Campbell Scientific CR510 User Manual

CR510 DATALOGGER

OPERATOR'S MANUAL

REVISION: 2/03

COPYRIGHT (c) 1986-2003 CAMPBELL SCIENTIFIC, INC.

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WARRANTY AND ASSISTANCE

The

CR510 DATALOGGER

materials and workmanship under normal use and service for thirty-six (36) months from date of shipment
unless specified otherwise. Batteries have no warranty. CAMPBELL SCIENTIFIC, INC.'s obligation under
this warranty is limited to repairing or replacing (at CAMPBELL SCIENTIFIC, INC.'s option) defective
products. The customer shall assume all costs of removing, reinstalling, and shipping defective products
to CAMPBELL SCIENTIFIC, INC. CAMPBELL SCIENTIFIC, INC. will return such products by surface
carrier prepaid. This warranty shall not apply to any CAMPBELL SCIENTIFIC, INC. products which have
been subjected to modification, misuse, neglect, accidents of nature, or shipping damage. This warranty
is in lieu of all other warranties, expressed or implied, including warranties of merchantability or fitness for
a particular purpose. CAMPBELL SCIENTIFIC, INC. is not liable for special, indirect, incidental, or
consequential damages.

Products may not be returned without prior authorization. To obtain a Returned Materials Authorization
(RMA), contact CAMPBELL SCIENTIFIC, INC., phone [phone]. After an applications engineer
determines the nature of the problem, an RMA number will be issued. Please write this number clearly on
the outside of the shipping container. CAMPBELL SCIENTIFIC's shipping address is:

CAMPBELL SCIENTIFIC, INC.

RMA#_____
815 West 1800 North
Logan, Utah 84321-1784

is warranted by CAMPBELL SCIENTIFIC, INC. to be free from defects in

CAMPBELL SCIENTIFIC, INC. does not accept collect calls.
Non-warranty products returned for repair should be accompanied by a purchase order to cover the repair.

815 W. 1800 N.
Logan, UT 84321-1784
USA
Phone [phone]
FAX [phone]
www.campbellsci.com

Campbell Scientific Canada Corp.
11564 -149th Street
Edmonton, Alberta T5M 1W7
CANADA
Phone [phone]
FAX [phone]

Campbell Scientific Ltd.
Campbell Park
80 Hathern Road
Shepshed, Loughborough
LE12 9GX, U.K.
Phone [phone]
FAX [phone]

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CR510 MEASUREMENT AND CONTROL MODULE

TABLE OF CONTENTS

PAGE

OV1. PHYSICAL DESCRIPTION

OV1.1 Analog Inputs ......................................................................................................................OV-1

OV1.2 Excitation Outputs............................................................................................................... OV-2

OV1.3 Pulse Inputs ........................................................................................................................ OV-2

OV1.4 Digital I/O Ports................................................................................................................... OV-2

OV1.5 Analog Ground (AG) ........................................................................................................... OV-2

OV1.6 12 V, Power Ground (G), and Earth Terminals................................................................... OV-2

OV1.7 5 V Output........................................................................................................................... OV-2

OV1.8 Serial I/O .............................................................................................................................OV-2

OV1.9 Connecting Power to the CR510......................................................................................... OV-2

OV2. MEMORY AND PROGRAMMING CONCEPTS

OV2.1 Internal Memory..................................................................................................................OV-3

OV2.2 Program Tables, Execution Interval and Output Intervals .................................................. OV-5

OV2.3 CR510 Instruction Types..................................................................................................... OV-6

OV3. COMMUNICATING WITH CR510

OV3.1 Keyboard/Display................................................................................................................OV-8

OV3.2 Using Computer with Datalogger Support Software ........................................................... OV-9

OV3.3 ASCII Terminal or Computer with Terminal Emulator......................................................... OV-9

OV4. PROGRAMMING THE CR510

OV4.1 Programming Sequence ................................................................................................... OV-10

OV4.2 Instruction Format............................................................................................................. OV-10

OV4.3 Entering a Program...........................................................................................................OV-11

OV5. PROGRAMMING EXAMPLES

OV5.1 Sample Program 1............................................................................................................ OV-12

OV5.2 Editing an Existing Program.............................................................................................. OV-14

OV5.3 Setting the Datalogger Time ............................................................................................. OV-15

OV6. DATA RETRIEVAL OPTIONS.................................................................................... OV-16

OV7. SPECIFICATIONS.......................................................................................................... OV-18

PROGRAMMING

1. FUNCTIONAL MODES

1.1 Datalogger Programs - ∗1, ∗2, ∗3, and ∗4 Modes...................................................................1-1

1.2 Setting and Displaying the Clock - ∗5 Mode............................................................................1-4

1.3 Displaying/Altering Input Memory, Flags, and Ports - ∗6 Mode ..............................................1-4

1.4 Compiling and Logging Data - ∗0 Mode..................................................................................1-5

1.5 Memory Allocation - ∗A ...........................................................................................................1-5

1.6 Memory Testing and System Status - ∗B................................................................................1-9

1.7 ∗C Mode -- Security...............................................................................................................1-11

1.8 ∗D Mode -- Save or Load Program .......................................................................................1-11

i

CR510 TABLE OF CONTENTS

2. INTERNAL DATA STORAGE

2.1 Final Storage Areas, Output Arrays, and Memory Pointers................................................... 2-1

2.2 Data Output Format and Range Limits .................................................................................. 2-3

2.3 Displaying Stored Data on Keyboard/Display - ∗7 Mode........................................................ 2-3

3. INSTRUCTION SET BASICS

3.1 Parameter Data Types........................................................................................................... 3-1

3.2 Repetitions ............................................................................................................................. 3-1

3.3 Entering Negative Numbers................................................................................................... 3-1

3.4 Indexing Input Locations ........................................................................................................ 3-1

3.5 Voltage Range and Overrange Detection .............................................................................. 3-2

3.6 Output Processing.................................................................................................................. 3-2

3.7 Use of Flags: Output and Program Control........................................................................... 3-3

3.8 Program Control Logical Constructions ................................................................................. 3-4

3.9 Instruction Memory and Execution Time................................................................................ 3-7

3.10 Error Codes.......................................................................................................................... 3-11

DATA RETRIEVAL/COMMUNICATION

4. EXTERNAL STORAGE PERIPHERALS

4.1 On-Line Data Transfer - Instruction 96 .................................................................................. 4-1

4.2 Manually Initiated Data Output - ∗8 Mode.............................................................................. 4-3

4.3 Printer Output Formats........................................................................................................... 4-3

4.4 Storage Module...................................................................................................................... 4-4

4.5 ∗9 Mode -- SM192/716 Storage Module Commands............................................................. 4-5

5. TELECOMMUNICATIONS

5.1 Telecommunications Commands .......................................................................................... 5-1

5.2 Remote Programming of the CR510...................................................................................... 5-4

6. 9-PIN SERIAL INPUT/OUTPUT

6.1 Pin Description....................................................................................................................... 6-1

6.2 Enabling and Addressing Peripherals.................................................................................... 6-2

6.3 Ring Interrupts........................................................................................................................ 6-3

6.4 Interrupts During Data Transfer ............................................................................................. 6-3

6.5 Modem/Terminal Peripherals................................................................................................. 6-4

6.6 Synchronous Device Communication .................................................................................... 6-4

6.7 Modem/Terminal and Computer Requirements..................................................................... 6-5

PROGRAM EXAMPLES

7. MEASUREMENT PROGRAMMING EXAMPLES

7.1 Single-Ended Voltage 107 Temperature Probe ..................................................................... 7-1

7.2 Differential Voltage Measurement.......................................................................................... 7-1

7.3 HMP35C Temperature and RH Probe ................................................................................... 7-2

7.4 Anemometer with Photochopper Output................................................................................ 7-3

7.5 Tipping Bucket Rain Gage with Long Leads.......................................................................... 7-4

7.6 100 ohm PRT in 4 Wire Half Bridge....................................................................................... 7-4

7.7 100 ohm PRT in 3 Wire Half Bridge....................................................................................... 7-6

ii

CR510 TABLE OF CONTENTS

7.8 100 ohm PRT in 4 Wire Full Bridge ........................................................................................7-7

7.9 Pressure Transducer - 4 Wire Full Bridge ..............................................................................7-8

7.10 Lysimeter - 6 Wire Full Bridge.................................................................................................7-9

7.11 227 Gypsum Soil Moisture Block ..........................................................................................7-11

7.12 Nonlinear Thermistor in Half Bridge......................................................................................7-12

7.13 Water Level - Geokon's Vibrating Wire Pressure Sensor.....................................................7-13

7.14 4 to 20 mA Sensor Using CURS100 Terminal Input Module................................................7-17

8. PROCESSING AND PROGRAM CONTROL EXAMPLES

8.1 Computation of Running Average...........................................................................................8-1

8.2 Rainfall Intensity......................................................................................................................8-2

8.3 Sub 1 Minute Output Interval Synched to Real Time..............................................................8-3

8.4 Switch Closures on Control Port (Rain Gage).........................................................................8-3

8.5 Converting 0-360 Wind Direction Output to 0-540 for Strip Chart...........................................8-4

8.6 Use of 2 Final Storage Areas - Saving Data Prior to Event ....................................................8-5

8.7 Logarithmic Sampling Using Loops.........................................................................................8-6

INSTRUCTIONS

9. INPUT/OUTPUT INSTRUCTIONS.....................................................................................9-1

10. PROCESSING INSTRUCTIONS......................................................................................10-1

11. OUTPUT PROCESSING INSTRUCTIONS...................................................................11-1

12. PROGRAM CONTROL INSTRUCTIONS......................................................................12-1

MEASUREMENTS

13. CR510 MEASUREMENTS

13.1 Fast and Slow Measurement Sequence ...............................................................................13-1

13.2 Single-Ended and Differential Voltage Measurements .........................................................13-2

13.3 The Effect of Sensor Lead Length on the Signal Settling Time ............................................13-3

13.4 Bridge Resistance Measurements ......................................................................................13-12

13.5 Resistance Measurements Requiring AC Excitation ..........................................................13-16

13.6 Calibration Process.............................................................................................................13-17

INSTALLATION

14. INSTALLATION AND MAINTENANCE

14.1 Protection from the Environment ..........................................................................................14-1

14.2 Power Requirements.............................................................................................................14-1

14.3 Campbell Scientific Power Supplies......................................................................................14-2

14.4 Solar Panels..........................................................................................................................14-5

14.5 Direct Battery Connection to the CR510 Terminal Strip........................................................14-5

14.6 Vehicle Power Supply Connections ......................................................................................14-5

14.7 Grounding .............................................................................................................................14-6

14.8 Terminal Strip........................................................................................................................14-7

14.9 Use of Digital I/O Ports for Switching Relays........................................................................14-7

14.10 Maintenance..........................................................................................................................14-9

iii

CR510 TABLE OF CONTENTS

APPENDICES

A. GLOSSARY..............................................................................................................................A-1

B. ADDITIONAL TELECOMMUNICATIONS INFORMATION

B.1 Telecommunications Command with Binary Responses.......................................................B-1

B.2 Final Storage Format .............................................................................................................B-3

B.3 Generation of Signature.........................................................................................................B-5

B.4 ∗D Commands to Transfer Program with Computer..............................................................B-5

C. ASCII TABLE...........................................................................................................................C-1

D. DATALOGGER INITIATED COMMUNICATIONS

D.1 Introduction.............................................................................................................................D-1

D.2 Example Phone Callback Program Based On A Condition ...................................................D-1

D.3 PC208 DOS Computer Software and It’s Computer Setup ...................................................D-2

E. CALL ANOTHER DATALOGGER VIA PHONE OR RF

E.1 Introduction.............................................................................................................................E-1

E.2 Programming..........................................................................................................................E-1

E.3 Programming for the Calling CR510 ...................................................................................... E-1

E.4 Remote Datalogger Programming......................................................................................... E-3

F. MODBUS ON THE CR10 AND CR510

F.1 Terminology............................................................................................................................F-1

F.2 Communications and Compatibility........................................................................................ F-1

F.3 More on Modbus .................................................................................................................... F-2

G. TD OPERATING SYSTEM ADDENDUM FOR CR510, CR10X, AND

CR23X MANUALS

LIST OF TABLES..........................................................................................................................LT-1

LIST OF FIGURES........................................................................................................................ LF-1

iv

FEATURES OF CR510

The CR510 is programmed in the same way as the CR500 and executes existing CR500 programs. The
CR510 has a clock and memory backed by an internal battery. This keeps the time and data while the
CR510 is not connected to external power.

GENERAL

POWER UP

When primary power is applied to the CR510, it
tests the FLASH memory and loads the current
program to RAM. After the program compiles
successfully, the CR510 begins executing the
program. If the ring line on the 9 pin connector
is raised while the CR510 is testing memory,
there will be a 128 second delay before
compiling and running the program. This can
be used to edit or change the program before it
starts running. To raise the ring line, press any
key on the CR10KD keyboard display or call the
CR510 with the computer during the power up
sequence (i.e., while “HELLO” is displayed on
the CR10KD).

LITHIUM BATTERY

A lithium battery powers the clock and RAM
when the primary 12 VDC is not connected.
The clock is more accurate when connected to
the primary 12 VDC power supply. The lithium
battery has an expected life of four years of
continuous use. That is, the primary 12 VDC
can be disconnected for four years before the
clock stops and data are lost. The voltage of
the lithium battery is found in the 8th window of
the ∗B mode. The voltage of a new battery is
approximately 3 volts. The lithium battery must
be replaced when its voltage falls below 2.4
VDC. (Section 14.11)

INTERNAL FLASH PROGRAM STORAGE

Several programs can be stored in the CR510
Flash Memory and later recalled and run using
the ∗D Mode. (Section 1.8)

LOW VOLTAGE INDICATOR

When primary power falls below 9.6 VDC, the
CR510 stops executing its programs. The Low
Voltage Counter (∗B window 9) is incremented by
one each time the primary power drops below 9.6
VDC and E10 is displayed on the CR10KD. A
double dash (--) in the 9th window of the ∗B mode
indicates that the CR510 is currently in a low
primary power mode. (Section 1.6)

CONTROL PORT COUNTERS AND INTERRUPTS

Control port 2 can be used to measure switch
closures up to 40 Hz. Control port 2 can also
be used to activate interrupt driven subroutine

98. (Sections 1.1.2, 9, Instruction 3)

TAPE

Cassette tape is not supported as a data
retrieval method with the CR510.

NEW INSTRUCTIONS

P69 Wind Vector
P75 Histogram
P98 Send Character

TWO FINAL STORAGE AREAS

Final Storage can be divided into two parts:
Final Storage Area 1 and Final Storage Area 2.
Final Storage Area 1 is the default storage area
and the only one used if the operator does not
specifically allocate memory to Area 2. Each
Final Storage Area can be represented as ring
memory, where the newest data writes over the
oldest data.

v

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SELECTED OPERATING DETAILS

1. Storing Data - Data are stored in Final
Storage only by Output Processing
Instructions and only when the Output Flag
(Flag 0) is set. (Sections OV4.1.1 and

3.7.1)

2. Storing Date and Time - Date and time are
stored with the data in Final Storage ONLY
if the Real Time Instruction 77 is used.
(Section 11)

3. Data Transfer - On-line data transfer from
Final Storage to peripherals (printer,
Storage Module, etc.) occurs only if enabled
with Instruction 96 in the datalogger
program. (Sections 4 and 12)

4. Final Storage Resolution - All Input
Storage values are displayed (∗6 mode) as
high resolution with a maximum value of

99999. However, the default resolution for
data stored in Final Storage is low
resolution, maximum value of 6999.
Results exceeding 6999 are stored as 6999
unless Instruction 78 is used to store the
values in Final Storage as high resolution
values. (Sections 2.2.1 and 11)

5. Floating Point Format - The computations
performed in the CR510 use floating point
arithmetic. CSI's 4 byte floating point
numbers contain a 23 bit binary mantissa
and a 6 bit binary exponent. The largest
and smallest numbers that can be stored
and processed are 9 x 10

18

and 1 x 10

-19

,

respectively. (Section 2.2.2)

6. Erasing Final Storage - Data in Final
Storage can be erased without altering the
program by using the ∗A Mode to repartition
memory. (Section 1.5.2)

7. ALL memory can be erased and the
CR510 completely reset by entering 98765
for the number of bytes allocated to
Program Memory. (∗A Window 5, Section

1.5.2)

vii

CAUTIONARY NOTES

1. Damage will occur to the analog input
circuitry if voltages in excess of ±16 V are
applied for a sustained period. Voltages in
excess of ±5 V will cause errors and
possible overranging on other analog input
channels.

2. When using the CR510 with the PS12LA,
remember that the sealed lead acid
batteries are permanently damaged if deep
discharged. The cells are rated at a 7 Ahr
capacity but experience a slow discharge
even in storage. It is advisable to maintain
a continuous charge on the PS12LA battery
pack, whether in operation or storage
(Section 14).

3. When connecting power to the CR510, first
connect the positive lead from the power
source to the 12 V terminal. Then connect
the negative lead to G. Connecting these
leads in the reverse order makes it easier
for the positive wire to accidentally touch a
grounded component and short out the
power supply (Section 14).

4. Voltages in excess of 5.6 volts applied to a
control port can cause the CR510 to
malfunction and damage the datalogger.

5. Voltage pulses can be counted by CR510
Pulse Counters configured for High
Frequency Pulses. However, when the
pulse is actually a low frequency signal
(below about 10 Hz) AND the positive
voltage excursion exceeds 5.6 VDC, the 5
VDC supply will start to rise, upsetting all
analog measurements.

Pulses whose positive voltage portion
exceed 5.6 VDC with a duration longer than
100 milliseconds need external
conditioning. See the description of the
Pulse count instruction in Section 9 for
details on the external conditioning.

6. The CR510 board is coated with a
conformal coating to protect against excess
humidity and corrosion. To protect the
datalogger from corrosion, additional
desiccant must be placed inside the
enclosure. To reduce vapor transfer into
the enclosure, plug the cable entry conduit
with Duct Seal, a putty-type sealant shipped
with Campbell Scientific enclosures and
available at most electrical supply houses.
DO NOT totally seal enclosures equipped
with lead acid batteries. Hydrogen
concentration may build up to explosive
levels.

viii

CR510 DATALOGGER OVERVIEW

The CR510 is a fully programmable datalogger/controller with non-volatile memory and a battery backed
clock in a small, rugged module. The combination of reliability, versatility, and telecommunications
support make it a favorite choice for networks and single logger applications.

Campbell Scientific Inc. provides four aids to operating the CR510:

1. This Overview

2. The CR510 Operator's Manual

3. The CR510 Prompt Sheet

4. Short Cut

This Overview introduces the concepts required to take advantage of the CR510's capabilities. Hands­on programming examples start in Section OV5. Working with a CR510 will help the learning process,
so don't just read the examples, do them. If you want to start this minute, go ahead and try the
examples, then come back and read the rest of the Overview.

The sections of the Operator's Manual which should be read to complete a basic understanding of the
CR510 operation are the Programming Sections 1-3, the portions of the data retrieval Sections 4 and 5
appropriate to the method(s) you are using (see OV6), and Section 14 which covers installation and
maintenance.

Section 6 covers details of serial communications. Sections 7 and 8 contain programming examples.
Sections 9-12 have detailed descriptions of each programming instruction, and Section 13 goes into
detail on the CR510 measurement procedures.

The Prompt Sheet is an abbreviated description of the programming instructions. Once familiar with the
CR510, it is possible to program it using only the Prompt Sheet as a reference, consulting the manual if
further detail is needed.

Short Cut is an easy-to-use DOS-based software program. It features point-and-click menus to guide
you through the process of creating simple CR510 programs. In addition to the downloadable program
file, Short Cut creates a table to simplify wiring sensors to the CR510.

Read the Selected Operating Details and Cautionary Notes at the front of the Manual before using the
CR510.

OV1. PHYSICAL DESCRIPTION

The CR510 was designed to provide a rugged
datalogger with a low per unit cost. Some of its
distinguishing physical features are:

• The CR510 does not have an integral
keyboard/display. The user accesses the
CR510 with the portable CR10KD Keyboard
Display or with a computer or terminal
(Section OV2).

• The power supply is external to the CR510.
This gives the user a wide range of options
(Section 14) for powering the CR510.

OV1.1 ANALOG INPUTS

The terminals labeled 1H to 4L are analog
inputs. These numbers refer to the high and
low inputs to the differential channels 1 and 2.
In a differential measurement, the voltage on
the H input is measured with respect to the
voltage on the L input. When making single­ended measurements, either the H or L input
may be used as an independent channel to
measure voltage with respect to the CR510
analog ground (AG). The single-ended
channels are numbered sequentially starting
with 1H; e.g., the H and L sides of differential
channel 1 are single-ended channels 1 and 2;
the H and L sides of differential channel 2 are
single-ended channels 3 and 4, etc.

OV-1

CR510 OVERVIEW

OV1.2 EXCITATION OUTPUTS

The terminals labeled E1, and E2 are precision,
switched excitation outputs used to supply
programmable excitation voltages for resistive
bridge measurements. DC or AC excitation
voltages between -2500 mV and +2500 mV are
user programmable (Section 9).

OV1.3 PULSE INPUTS

The terminals labeled P1, P2, and P3 are the
pulse counter inputs for the CR510. P1 and P2
are programmable for high frequency pulse, low
level AC, or switch closure (Section 9,
Instruction 3). C2/P3 can be configured to
count switch closures up to 40 Hz.

OV1.4 DIGITAL I/O PORTS

Terminal C1 is a digital Input/Output port. On
power-up it is configured as an input port,
commonly used for reading the status of an
external signal. High and low conditions are:
3V < high < 5.5V; -0.5V < low < 0.8V.

Configured as output the port allows on/off
control of external devices. A port can be set
high (5V ± 0.1V), set low (<0.1V), toggled or
pulsed (Sections 3, 8.3, and 12).

Port C2/P3 can be configured as pulse counters
for switch closures (Section 9, Instruction 3) or
used to trigger subroutine execution (Section

1.1.2), or serial SDI-12 communication.

OV1.5 ANALOG GROUND (AG)

OV1.7 5V OUTPUT

The 5V (±0.2%) output is commonly used to
power peripherals such as the QD1 Incremental
Encoder Interface and AVW1 Vibrating Wire
Interface.

The 5V output is common with pin 1 on the 9
pin serial connector; 200 mA is the maximum
combined current output.

OV1.8 SERIAL I/O

The 9 pin serial I/O port contains lines for serial
communication between the CR510 and external
devices such as computers, printers, Storage
Modules, etc. This port does NOT have the

same configuration as the 9 pin serial ports
currently used on many personal computers.

It has a 5VDC power line which is used to power
peripherals such as the Storage Modules. The
same 5VDC supply is used for the 5V output on
the terminal strip. It also has a continuous 12 V
power supply on pin 8 for external
communication devices such as the COM200
and COM300. Section 6 contains technical
details on serial communication.

OV1.9 CONNECTING POWER TO THE CR510

The CR510 can be powered by any 12VDC
source. The green power connector is a plug in
connector that allows the power supply to be
easily disconnected without unscrewing the
terminals. The Terminal Strip power connection
is reverse polarity protected. See Section 14 for
details on power supply connections.

The AG terminals are analog grounds, used as
the reference for single-ended measurements
and excitation return.

OV1.6 12V, POWER GROUND (G), AND EARTH

TERMINALS

The 12V and power ground (G) terminals are
used to supply 12V DC power to the datalogger.
The extra 12V and G terminals can be used to
connect other devices requiring 12V power.

The G terminals are also used to tie cable
shields to ground, and to provide a ground
reference for pulse counters and binary inputs.
The G terminals are directly connected to the
Earth terminal. For protection against transient
voltage spikes, Earth Ground should be
connected to a good earth ground (Section

14.7.1).

OV-2

CAUTION: The metal surfaces of the

CR510 Terminal Strip, and CR10KD
Keyboard Display are at the same potential
as power ground. To avoid shorting 12
volts to ground, connect the 12 volt lead
first, then connect the ground lead.

When primary power falls below 9.6 VDC, the
CR510 stops executing its programs. The Low
Voltage Counter (∗B window 9) is incremented
by one each time the primary power falls below

9.6 VDC and E10 is displayed on the CR10KD.
A double dash (--) in the 9th window of the ∗B
mode indicates that the CR510 is currently in a
low primary power mode. (Section 1.6)

The datalogger program and stored data remain
in memory, and the clock continues to keep

CR510 OVERVIEW

time when power is disconnected. The clock
and Static Random Access Memory (SRAM)
are powered by an internal lithium battery.

OV2. MEMORY AND PROGRAMMING

CONCEPTS

OV2.1 INTERNAL MEMORY

The standard CR510 has 128 K of Flash
Electrically Erasable Programmable Read Only
Memory (EEPROM) and 128 K Static Random
Access Memory (SRAM). The Flash EEPROM
stores the operating system and user programs.
RAM is used for data and running the program.
Data Storage can be expanded with an optional
Flash EEPROM (Figure OV2.1-1). The use of
the Input, Intermediate, and Final Storage in the
measurement and data processing sequence is
shown in Figure OV2.1-2. The five areas of
SRAM are:

1. System Memory - used for overhead tasks
such as compiling programs, transferring
data, etc. The user cannot access this
memory.

2. Progr am Memory - available for user
entered programs.

3. Input Storage - Input Storage holds the
results of measurements or calculations.
The ∗6 Mode is used to view Input Storage
locations for checking current sensor

readings or calculated values. Input
Storage defaults to 28 locations. Additional
locations can be assigned using the ∗A
Mode.

4. Intermediate Storage - Certain Processing
Instructions and most of the Output
Processing Instructions maintain
intermediate results in Intermediate
Storage. Intermediate storage is
automatically accessed by the instructions
and cannot be accessed by the user. The
default allocation is 64 locations. The
number of locations can be changed using
the ∗A Mode.

5. Final Storage - Final processed values are
stored here for transfer to printer, solid state
Storage Module or for retrieval via
telecommunication links. Values are stored
in Final Storage only by the Output
Processing Instructions and only when the
Output Flag is set in the user’s program.
Approximately 62,000 locations are
allocated to Final Storage on power up.
This number is reduced if Input or
Intermediate Storage is increased.

While the total size of these areas remains
constant, memory may be reallocated between
the areas to accommodate different
measurement and processing needs (∗A Mode,
Section 1.5).

OV-3

CR510 OVERVIEW

Flash Memory

(EEPROM)

Total 128 Kbytes

Operating System

(96 Kbytes)

Active Program

(16 Kbytes)

Stored Programs

(16 Kbytes)

How it works:

The Operating System is loaded into
Flash Memory at the factory. System
Memory is used while the CR510 is
running calculations, buffering data and
for general operating tasks.

Any time a user loads a program into
the CR510, the program is compiled in
SRAM and stored in the Active
Program areas. If the CR510 is
powered off and then on, the Active
Program is loaded from Flash and run.

The Active Program is run in SRAM to
maximize speed. The program
accesses Input Storage and
Intermediate Storage and stores data
into Final Storage for later retrieval by
the user.

The Active Program can be copied into
the Stored Programs area. While 98
program "names" are available, the
number of programs stored is limited
by the available memory. Stored
programs can be retrieved to become
the active program. While programs
are stored one at a time, all stored
programs must be erased at once. That
is because the flash memory can only
be written to once before it must be
erased and can only be erased in 16
Kbytes blocks.

SRAM

Total 128 Kbytes

System Memory

(4096 Bytes)

Active Program

(default 2048 Bytes)

Input Storage

(default 28 locations,
112 bytes)

Intermediate Storage

(default 64 locations,
256 bytes)

Final Storage Area 1

(default 62,280
locations, 124,560
bytes)

Final Storage Area 2

(default 0 locations,
0 bytes)

Optional

Flash EEPROM

OV-4

With the Optional Flash Memory, up to
2 Mbytes of additional memory can be
added to increase Final Storage by
another 524,288 data values per
Mbyte. The user can allocate this extra
memory to any combination of Area 1
or Area 2.

(Memory Areas separated by dashed
lines:
can be re-sized by the user.)

FIGURE OV2.1-1. CR510 Memory

Final Storage Area 1

and/or

Final Storage Area 2

(Additional 524,288
locations per Mbyte)

CR510 OVERVIEW

OV2.2 PROGRAM TABLES, EXECUTION

INTERVAL AND OUTPUT INTERVALS

The CR510 must be programmed before it will
make any measurements. A program consists
of a group of instructions entered into a

program table. The program table is given an
execution interval which determines how

frequently that table is executed. When the
table is executed, the instructions are executed
in sequence from beginning to end. After
executing the table, the CR510 waits the
remainder of the execution interval and then
executes the table again starting at the
beginning.

The interval at which the table is executed
generally determines the interval at which the
sensors are measured. The interval at which
data are stored is separate from how often the
table is executed, and may range from samples
every execution interval to processed
summaries output hourly, daily, or on longer or
irregular intervals.

Table 1.
Execute every x sec.

0.125 < x < 8191

Instructions are executed
sequentially in the order they
are entered in the table. One
complete pass through the
table is made each execution
interval unless program
control instructions are used
to loop or branch execution.

Normal Order:
MEASURE
PROCESS
CHECK OUTPUT COND.
OUTPUT PROCESSING

Table 2.
Execute every y sec.

0.125 < y < 8191

Table 2 is used if there is a
need to measure and
process data on a separate
interval from that in Table 1.

Programs are entered in Tables 1 and 2.
Subroutines, called from Tables 1 and 2, are
entered in Subroutine Table 3. The size of
program memory can be fixed or automatically
allocated by the CR510 (Section 1.5).

Table 1 and Table 2 have independent
execution intervals, entered in units of seconds
with an allowable range of 1/8 to 8191 seconds.
Subroutine Table 3 has no execution interval;
subroutines are only executed when called from
Table 1 or 2.

OV2.2.1 THE EXECUTION INTERVAL

The execution interval specifies how often the
program in the table is executed, which is
usually determined by how often the sensors
are to be measured. Unless two different

measurement rates are needed, use only one
table. A program table is executed sequentially

starting with the first instruction in the table and
proceeding to the end of the table.

Table 3.
Subroutines

A subroutine is executed
only when called from Table
1 or 2.

Subroutine Label
Instructions
End
Subroutine Label
Instructions
End
Subroutine Label
Instructions
End

FIGURE OV2.2-1. Program and Subroutine Tables

OV-5

CR510 OVERVIEW

Each instruction in the table requires a finite
time to execute. If the execution interval is less
than the time required to process the table, an
execution interval overrun occurs; the CR510
finishes processing the table and waits for the
next execution interval before initiating the
table. When an overrun occurs, decimal points
are shown on either side of the G on the display
in the LOG mode (∗0). Overruns and table
priority are discussed in Section 1.1.

OV2.2.2. THE OUTPUT INTERVAL

The interval at which output occurs must be an
integer multiple of the execution interval (e.g., a
table cannot have a 10 minute execution
interval and output every 15 minutes).

A single program table can have many different
output intervals and conditions, each with a
unique data set (Output Array). Program
Control Instructions are used to set the Output
Flag. The Output Processing Instructions which
follow the instruction setting the Output Flag
determine the data output and its sequence.
Each additional Output Array is created by
another Program Control Instruction checking a
output condition, followed by Output Processing
Instructions defining the data set to output.

OV2.3 CR510 INSTRUCTION TYPES

Figure OV2.3-1 illustrates the use of three
different instruction types which act on data.
The fourth type, Program Control, is used to
control output times and vary program
execution. Instructions are identified by
numbers.

1. INPUT/OUTPUT INSTRUCTIONS (1-12,
16-29, 105-106, 114, 117, 130, 131, Section

9) control the terminal strip inputs and
outputs (Figure OV1.1-2), storing the results
in Input Storage (destination). Multiplier
and offset parameters allow conversion of
linear signals into engineering units. The
Digital I/O Ports are also addressed with I/O
Instructions.

2. PROCESSING INSTRUCTIONS (30-68,
Section 10) perform numerical operations
on values located in Input Storage and
store the results back in Input Storage.
These instructions can be used to develop
high level algorithms to process
measurements prior to Output Processing.

3. OUTPUT PROCESSING INSTRUCTIONS
(69-82, Section 11) are the only
instructions which store data in Final
Storage. Input Storage values are
processed over time to obtain averages,
maxima, minima, etc. There are two types
of processing done by Output Instructions:

Intermediate and Final.
Intermediate processing normally takes

place each time the instruction is executed.
For example, when the Average Instruction
is executed, it adds the values from the
input locations being averaged to running
totals in Intermediate Storage. It also keeps
track of the number of samples.

Final processing occurs only when the
Output Flag is high (Section 3.7.1). The
Output Processing Instructions check the
Output Flag. If the flag is high, final values
are calculated and output. With the
Average, the totals are divided by the
number of samples and the resulting
averages sent to Final Storage.
Intermediate locations are zeroed and the
process starts over. The Output Flag, Flag

0, is set high by a Program Control
Instruction which must precede the Output
Processing Instructions in the user entered
program.

4. PROGRAM CONTROL INSTRUCTIONS
(83-98, 111, 120-121, Section 12) are used
for logic decisions, conditional statements,
and to send data to peripherals. They can
set flags and ports, compare values or
times, execute loops, call subroutines,
conditionally execute portions of the
program, etc.

OV-6

INPUT/OUTPUT
INSTRUCTIONS

Specify the conversion of a sensor signal
to a data value and store it in Input
Storage. Programmable entries specify:
(1) the measurement type
(2) the number of channels to measure
(3) the input voltage range
(4) the Input Storage Location
(5) the sensor calibration constants
used to convert the sensor output to
engineering units

I/O Instructions also control analog
outputs and digital control ports.

INPUT STORAGE

Holds the results of measurements or
calculations in user specified locations.
The value in a location is written over
each time a new measurement or
calculation stores data to the locations.

CR510 OVERVIEW

PROCESSING INSTRUCTIONS

Perform calculations with values in Input
Storage. Results are returned to Input
Storage. Arithmetic, transcendental and
polynomial functions are included.

OUTPUT PROCESSING
INSTRUCTIONS

Perform calculations over time on the
values updated in Input Storage.
Summaries for Final Storage are
generated when a Program Control
Instruction sets the Output Flag in
response to time or events. Results
may be redirected to Input Storage for
further processing. Examples include
sums, averages, max/min, standard
deviation, histograms, etc.

Output Flag set high

FINAL STORAGE

Final results from OUTPUT
PROCESSING INSTRUCTIONS are
stored here for on-line or interrogated
transfer to external devices (Figure
OV5.1-1). When memory is full, new
data overwrites the oldest data.

FIGURE OV2.3-1. Instruction Types and Storage Areas

INTERMEDIATE STORAGE

Provides temporary storage for
intermediate calculations required by the
OUTPUT PROCESSING INSTRUCTIONS;
for example, sums, cross products,
comparative values, etc.

OV-7

CR510 OVERVIEW

OV3. COMMUNICATING WITH CR510

An external device must be connected to the
CR510's Serial I/O port to communicate with the
CR510. This may be either Campbell
Scientific's CR10KD Keyboard Display or a
computer/terminal.

The CR10KD is powered by the CR510 and
connects directly to the serial port via the SC12
cable (supplied with the CR10KD). No
interfacing software is required.

Computer communication and program editing
is accomplished using Campbell Scientific's
datalogger support software. This package
contains a program editor (EDLOG), datalogger
communications, automated
telecommunications data retrieval, a data
reduction program, and programs to retrieve
data from Campbell Scientific Storage Modules.

To participate in the programming examples
(Section OV5) you must communicate with the
CR510. Read Section OV3.1 if the CR10KD is
being used or Section OV3.2 if datalogger
support software is being used.

OV3.1 KEYBOARD/DISPLAY

The SC12 cable (supplied with the CR10KD) is
used to connect the Keyboard/Display to the 9
pin Serial I/O port on the CR510.

OV3.1.1 FUNCTIONAL MODES

CR510/User interaction is broken into different
functional MODES (e.g., programming the
measurements and output, setting time,
manually initiating a block data transfer to
Storage Module, etc.). The modes are referred
to as Star (∗) Modes since they are accessed by
first keying ∗, then the mode number or letter.
Table OV3.1-1 lists the CR510 Modes.

TABLE OV3.1-1. ∗∗∗∗ Mode Summary

Key Mode

0

∗
∗
∗
∗
∗
∗
∗

LOG data and indicate active Tables

1

Program Table 1

2

Program Table 2

3

Program Table 3, subroutines only

4

Parameter Entry Table

5

Display/set real time clock

6

Display/alter Input Storage data,
toggle flags or control ports.

7

∗
∗
∗
∗
∗
∗
∗
∗

Display Final Storage data

8

Final Storage data transfer to peripheral

9

Storage Module commands

A

Memory allocation/reset

B

Signature/status

C

Security

D

Save/load Program

#

Used with TGT1 satellite transmitter

If the Keyboard/Display is connected to the
CR510 prior to being powered up, the "HELLO"
message is displayed while the CR510 checks
memory. The total size of memory is then
displayed (256 for 256 K bytes of memory).
When the CR10KD is plugged in after the
CR510 has powered up, the display is
meaningless until "∗" is pressed to enter a
mode.

This manual describes direct interaction with
the CR510. If you have a CR10KD, work
through the direct programming examples in
this overview in addition to using EDLOG and
you will have the basics of CR510 operation as
well as an appreciation for the help provided by
the software.

OV-8

OV3.1.2 KEY DEFINITION

Keys and key sequences have specific
functions when using the CR10KD keyboard or
a computer/terminal in the remote keyboard
state (Section 5). Table OV3.1-2 lists these
functions. In some cases, the exact action of a
key depends on the mode the CR510 is in and
is described with the mode in the manual.

CR510 OVERVIEW

TABLE OV3.1-2 Key Description/Editing

Functions

Key Action

0

9

-

∗

Key numeric entries into display
Enter Mode (followed by Mode

Number)

A
B
C

Enter/Advance
Back up
Change the sign of a number or index

an input location to loop counter

D
#

Enter the decimal point
Clear the rightmost digit keyed into

the display

# A

Advance to next instruction in
program table (∗1, ∗2, ∗3) or to next
Output Array in Final Storage (∗7)

# B

Back up to previous instruction in
program table or to previous Output
Array in Final Storage

# D
# 0

Delete entire instruction
(then A) Back up to the start of the

current array.

When using a computer/terminal to communicate
with the CR510 (Telecommunications remote
keyboard state) there are some keys available in
addition to those found on the CR10KD. Table
OV3.1-3 lists these keys.

TABLE OV3.1-3. Additional Keys Allowed in

Telecommunications

Key Action

- Change Sign, Index (same as C)
CR Enter/advance (same as A)
: Colon (used in setting time)
S or ^S Stops transmission of data (10

second time-out; any character
restarts)

C or ^C Aborts transmission of Data

When using the support software, the
computer’s baud rate, port, and modem types
are specified and stored in a file for future use.

The simplest and most common interface is the
SC32A Optically Isolated RS232 Interface. The
SC32A converts and optically isolates the
voltages passing between the CR510 and the
external terminal device.

The SC12 Two Peripheral cable which comes
with the SC32A is used to connect the serial I/O
port of the CR510 to the 9 pin port of the SC32A
labeled "Datalogger". Connect the
"Terminal/Printer" port of the SC32A to the
serial port of the computer with a straight 25 pin
cable or, if the computer has a 9 pin serial port,
a standard 9 to 25 pin adapter cable.

OV3.3 ASCII TERMINAL OR COMPUTER WITH

TERMINAL EMULATOR

Devices which can be used to communicate
with the CR510 include standard ASCII
terminals and computers programmed to
function as a terminal emulator. See Section

6.7 for details.
To communicate with any device other than the

CR10KD, the CR510 enters its Telecom­munications Mode and responds only to valid
telecommunications commands. Within the
Telecommunications Mode, there are 2 "states";
the Telecommunications Command state and the
Remote Keyboard state. Communication is
established in the Telecommunications command
state. One of the commands is to enter the
Remote Keyboard state (Section 5).

The Remote Keyboard state allows the
keyboard of the computer/terminal to act like
the CR10KD keyboard. Various datalogger
modes may be entered, including the mode in
which programs may be keyed in to the CR510
from the computer/terminal.

OV3.2 USING COMPUTER WITH DATALOGGER

SUPPORT SOFTWARE

Direct datalogger communication programs in
the datalogger support software provide menu
selection of tools to perform the datalogger
functions (e.g., set clock, send program,
monitor measurements, and collect data). The
user also has the option of directly entering
keyboard commands via a built-in terminal
emulator (Section OV3.3).

OV4. PROGRAMMING THE CR510

A datalogger program is created on a computer
using EDLOG or one of the programming aids
such as Short Cut. A program can also be
entered directly into the datalogger. Section
OV4.3 describes options for loading the
program into the CR510.

OV-9

CR510 OVERVIEW

OV4.1 PROGRAMMING SEQUENCE

In routine applications, the CR510 measures
sensor output signals, processes the
measurements over some time interval and
stores the processed results. A generalized
programming sequence is:

1. Enter the execution interval. In most cases,
the execution interval is determined by the
desired sensor scan rate.

2. Enter the Input/Output instructions required
to measure the sensors.

3. If processing in addition to that provided by
the Output Processing Instructions (step 5)
is required, enter the appropriate
Processing Instructions.

4. Enter the Program Control Instruction to
test the output condition and set the Output
Flag when the condition is met. For
example, use

Instruction 92 to output based on time.
Instruction 86 to output every execution

interval.
Instruction 88 or 89 to output based on a

comparison of values in input locations.
This instruction must precede the Output

Processing Instructions which store data in
Final Storage. Instructions are described in
Sections 9 through 12.

Execution intervals and output intervals set with
Instruction 92 are synchronized with datalogger
time starting at midnight.

OV4.2 INSTRUCTION FORMAT

Instructions are identified by an instruction
number. Each instruction has a number of
parameters that give the CR510 the information
it needs to execute the instruction.

The CR510 Prompt Sheet has the instruction
numbers in red, with the parameters briefly
listed in columns following the description.
Some parameters are footnoted with further
description under the "Instruction Option Codes"
heading.

For example, Instruction 73 stores the
maximum value that occurred in an Input
Storage location over the output interval.

P73 Maximum

1: Reps
2: TimeOption
3: Loc

The instruction has three parameters (1)
REPetitionS, the number of sequential Input
Storage locations on which to find maxima, (2)
TIME, an option of storing the time of
occurrence with the maximum value, and (3)
LOC the first Input Storage location operated on
by the Maximum Instruction. The codes for the
TIME parameter are listed in the "Instruction
Option Codes".

5. Enter the Output Processing Instructions to
store processed data in Final Storage. The
order in which data are stored is determined
by the order of the Output Processing
Instructions in the table.

6. Repeat steps 4 and 5 for additional outputs
on different intervals or conditions.

NOTE: The program must be executed for
output to occur. Therefore, the interval at
which the Output Flag is set must be evenly
divisible by the execution interval. For
example, with a 2 minute execution interval
and a 5 minute output interval, the program
will only be executed on the even multiples
of the 5 minute intervals, not on the odd.
Data will be output every 10 minutes
instead of every 5 minutes.

OV-10

The repetitions parameter specifies how many
times an instruction's function is to be repeated.
For example, four 107 thermistor probes may be
measured with a single Instruction 11, Temp­107, with four repetitions. Parameter 2 specifies
the input channel of the first thermistor (the
probes must be connected to sequential
channels). Parameter 4 specifies the Input
Storage location in which to store measurements
from the first thermistor. If location 5 were used
and the first probe was on channel 1, the
temperature of the thermistor on channel 1
would be stored in input location 5, the
temperature from channel 2 in input location 6,
etc.

Detailed descriptions of the instructions are
given in Sections 9-12. Entering an instruction
into a program table is described in OV5.

CR510 OVERVIEW

OV4.3 ENTERING A PROGRAM

Programs are entered into the CR510 in one of
three ways:

1. Keyed in using the CR10KD keyboard.

2. Loaded from a pre-recorded listing using
the ∗D Mode. There are 2 types of
storage/input:
a. Stored on disk/sent from computer.
b. Stored/loaded from Storage Module.

3. Loaded from internal Flash Memory or
Storage Module upon power-up.

A program is created by keying it directly into
the datalogger as described in Section OV5, or
on a PC using EDLOG or a programming aid
such as Short Cut.

Program files (.DLD) can be downloaded directly to
the CR510 using Campbell’s datalogger support
software. Communication via direct wire,
telephone, or Radio Frequency (RF) is supported.

Programs can be copied to a Storage Module
with the appropriate software. Using the ∗D
Mode to save or load a program from a Storage
Module is described in Section 1.8.

Once a program is loaded in the CR510, the
program will be stored in flash memory and will
automatically be loaded and run when the
datalogger is powered-up.

OV5. PROGRAMMING EXAMPLES

The following examples stress direct interaction
with the CR510 using the CR10KD. At the
beginning of each example is an EDLOG listing
of the program. You can also participate in the
example by entering the program in EDLOG
and sending it to the CR510 and viewing
measurements with Campbell’s datalogger
support software. If you have the CR10KD,
work through the examples as well as using
EDLOG. You will learn the basics of CR510
operation as well as an appreciation for the help
provided by the software.

We will start with a simple programming
example. There is a brief explanation of each
step to help you follow the logic. When the
example uses an instruction, find it on the
Prompt Sheet and follow through the description
of the parameters. Using the Prompt Sheet
while going through these examples will help
you become familiar with its format. Sections 9­12 have more detailed descriptions of the
instructions.

Connect the CR510 to the CR10KD
Keyboard/Display or a terminal (Section OV3).
Hook up the power leads as described in
Section OV1.2. The programming steps in the
following examples use the keystrokes possible
on the keyboard/display. With a terminal, some
responses will be slightly different.

The program on power up function can also be
achieved by using a Storage Module. Up to 8
programs can be stored in the Storage Module,
the programs may be assigned any of the
numbers 1-8. If the Storage Module is
connected when the CR510 is powered-up the
CR510 will automatically load program number
8, provided that a program 8 is loaded in the
Storage Module (Section 1.8). The program
from the Storage Module will replace the active
program in flash memory.

If the CR10KD is connected to the CR510 when
it is powered up, the display will show:

Display Explanation
HELLO On power-up, the CR510

displays "HELLO" while it
checks the memory (this
display occurs only with the
CR10KD).

after a few seconds delay

:0256 The size of the machine's total

memory, 256 K (1280 if 1 meg
option).

When primary power is applied to the CR510, it
tests the FLASH memory and loads the current
program to RAM. After the program compiles
successfully, the CR510 begins executing the
program. If the ring line on the 9 pin connector
is raised while the CR510 is testing memory,

OV-11

CR510 OVERVIEW

there will be a 128 second delay before
compiling and running the program. This can
be used to edit or change the program before it
starts running. To raise the ring line, press any
key on the CR10KD keyboard display or call the
CR510 with the computer during the power up
sequence (i.e., while “HELLO” is displayed on
the CR10KD).

In order to ensure that there is no active
program in the CR510, we will load an empty
program using the *D Mode:

Display Will Show:

Key (ID:Data) Explanation

∗

00:00 Enter mode

D

13:00 Enter *D Mode

7

13:7 7 is command to load

program from flash

A

07:00 Execute command 7,

CR510 is ready for
program number

0

07:0 Load Program 0 (empty

program)

A

Execute program load,
after a short wait, the
display will show

13:0000 Indicating that the

command is complete.

OV5.1 SAMPLE PROGRAM 1

EDLOG Listing Program 1:
*Table 1 Program

01: 5.0 Execution Interval (seconds)
1: Internal Temperature (P17)

1: 1 Loc [ CR510Temp ]

2: Do (P86)

1: 10 Set Output Flag High

3: Sample (P70)

1: 1 Reps
2: 1 Loc [ CR510Temp ]

In this example the CR510 is programmed to
read its own internal temperature (using a built
in thermistor) every 5 seconds and to send the
results to Final Storage.

Display Will Show:

Key (ID:Data) Explanation

∗

00:00 Enter mode.

1

01:0000 Enter Program Table 1.

A

01:0.0000 Advance to execution

interval (In seconds)

5

01:5 Key in an execution

interval of 5 seconds.

A

01:P00 Enter the 5 second

execution interval and
advance to the first program
instruction location.

1 7

01:P17 Key in Instruction 17

which directs the CR510
to measure the internal
temperature in degrees
C. This is an
Input/Output Instruction.

A

01:0000 Enter Instruction 17 and

advance to the first
parameter.

1

01:1 The input location to

store the measurement,
location 1.

A

02:P00 Enter the location # and

advance to the second
program instruction.

The CR510 is now programmed to read the internal
temperature every 5 seconds and place the reading
in Input Storage Location 1. The program can be
compiled and the temperature displayed.

Display Will Show:

Key (

∗

ID:Data) Explanation

0LOG 1 Exit Table 1, enter ∗0

Mode, compile table and
begin logging.

∗

606:0000 Enter ∗6 Mode (to view

Input Storage).

A

01:21.234 Advance to first storage

location. Internal
datalogger temp. is

o

21.234

C (display shows
actual temperature so
exact value will vary).

OV-12

CR510 OVERVIEW

Wait a few seconds:

01:21.423 The CR510 has read the

sensor and stored the
result again. The internal
temp is now 21.423
The value is updated
every 5 seconds when
the table is executed. At
this point the CR510 is
measuring the
temperature every 5
seconds and sending the
value to Input Storage.
No data are being saved.
The next step is to have
the CR510 send each
reading to Final Storage.
(Remember, the Output
Flag must be set first.)

∗

101:0000 Exit ∗6 Mode. Enter

program table 1.

2 A

02:P00 Advance to 2nd

instruction location (this
is where we left off).

8 6

02:P86 This is the DO instruction

(a Program Control
Instruction).

A

01:00 Enter 86 and advance to

the first parameter (which
will specify the command
to execute).

1 0

01:10 This command sets the

Output Flag. (Flag 0)

A

03:P00 Enter 10 and advance to

third program instruction.

7 0

03:P70 The SAMPLE instruction.

It directs the CR510 to
take a reading from an
Input Storage location
and send it to Final
Storage (an Output
Processing Instruction).

A

01:0000 Enter 70 and advance to

the first parameter
(repetitions).

1

01:1 There is only one input

location to sample;
repetitions = 1.

A

02:0000 Enter 1 and advance to

second parameter (Input

Storage location to
sample).

1

02:1 Input Storage Location 1,

o

C.

A

04:P00 Enter 1 and advance to

where the temperature is
stored.

fourth program
instruction.

∗

00:00 Exit Table 1.

0

LOG 1 Enter ∗0 Mode, compile

program, log data.

The CR510 is now programmed to measure the
internal temperature every 5 seconds and send
each reading to Final Storage. Values in Final

∗

Storage can be viewed using the

7 Mode.

Display Will Show:

Key (

∗

ID:Data) Explanation

707: 13.000 Enter ∗7 Mode. The

Data Storage Pointer
(DSP) is at Location 13
(in this example).

A

01: 0102 Advance to the first

value, the Output Array
ID. 102 indicates the
Output Flag was set by
the second instruction in
Program Table 1.

A

02: 21.23 Advance to the first

stored temperature.

A

01: 0102 Advance to the next

output array. Same
Output Array ID.

A

02: 21.42 Advance to 2nd stored

temp, 21.42 deg. C.

There are no date and time tags on the data.
They must be put there with Output Instruction

77. Instruction 77 is used in the next example.
If a terminal is used to communicate with the

CR510, Telecommunications Commands
(Section 5) can be used to view entire Output
Arrays (in this case the ID and temperature) at
the same time.

OV-13

CR510 OVERVIEW

OV5.2 EDITING AN EXISTING PROGRAM

When editing an existing program in the CR510,
entering a new instruction inserts the
instruction; entering a new parameter replaces
the previous value.

To insert an instruction, enter the program table
and advance to the position where the
instruction is to be inserted (i.e., P in the data
portion of the display) key in the instruction
number, and then key A. The new instruction
will be inserted at that point in the table,

Instruction # Parameter
(Loc:Entry) (

Par#:Entry) Description
∗1 Enter Program Table 1
01:60 60 second (1 minute) execution interval

# D

Key

until 01:P00 Erase previous Program before

is displayed continuing.
01:P11 Measure reference temperature

01:1 Store temp in Location 1
02:5
03:3
04:1
05:1.0
06:0.0

advance through and enter the parameters.
The instruction that was at that point and all
instructions following it will be pushed down to
follow the inserted instruction.

An instruction is deleted by advancing to the
instruction number (P in display) and keying #D
(Table 4.2-1).

To change the value entered for a parameter,
advance to the parameter and key in the correct
value then press A. Note that the new value is
not entered until A is keyed.

SAMPLE PROGRAM 2

02:P92 If Time instruction

01:0 0 minutes into the interval
02:60 60 minute interval
03:10 Set Output Flag 0

The CR510 is programmed to measure the datalogger internal temperature every sixty seconds.
The If Time instruction sets the Output Flag high at the beginning of every hour. Next, the
Output Instructions for time and average are added.

03:P77 Output Time instruction

01:110 Store Julian day, hour, and minute

04:P71 Average instruction

01:1 one repetition
02:1 Location 1 - source of temps. to be averaged

05:P92 If Time instruction

01:0 0 minutes into the interval
02:1440 1440 minute interval (24 hrs.)
03:10 Set Output Flag 0

06: P77 Output Time instruction

01:100 Store Julian day

OV-14

Instruction # Parameter
(Loc.:Entry) (

Par.#:Entry) Description

07: P73 Maximize instruction

01:1 One repetition
02:10 Output time of daily maximum in hours and minutes
03:2 Data source is Input Storage Location 1.

08: P74 Minimize instruction

01:1 One repetition
02:10 Output the time of the daily minimum in hours

03:1 Data source is Input Storage Location 1.

The program to make the measurements and to send the desired data to Final Storage has
been entered. At this point, Instruction 96 is entered to enable data transfer from Final Storage
to Storage Module.

09:P96 Activate Serial Data Output.

1:71 Output Final Storage data to Storage Module.

OV5.3 SETTING THE DATALOGGER TIME

CR510 OVERVIEW

and minutes

The next example shows how to set the datalogger date and time using the CR10KD. Here the
example reverts back to the key-by-key format.

Key Display

5

∗

A
1 9 9
A
1 9 7
A
1 3 2 4
A

∗

0

00:21:32 Enter ∗5 Mode. Clock running but perhaps not set correctly.
05:0000 Advance to location for year.

8

05:1998 Key in year (1998).
05:0000 Enter and advance to location for Julian day.
05:197 Key in Julian day.
05:0021 Enter and advance to location for hours and minutes (24 hr. time).
05:1324 Key in hrs.:min. (1:24 PM in this example).
:13:24:01 Clock set and running.
LOG 1 Exit ∗5, compile Table 1, commence logging data.

Explanation

OV-15

CR510 OVERVIEW

OV6. DATA RETRIEVAL OPTIONS

There are several options for data storage and
retrieval. These options are covered in detail in
Sections 2, 4, and 5. Figure OV6.1-1
summarizes the various possible methods.

Regardless of the method used, there are three
general approaches to retrieving data from a
datalogger.

1) On-line output of Final Storage data to a
peripheral storage device. On a regular
schedule, that storage device is either
"milked" of its data or is brought back to the
office/lab where the data is transferred to
the computer. In the latter case, a "fresh"
storage device is usually left in the field
when the full one is taken so that data
collection can continue uninterrupted.

2) Bring a storage device to the datalogger
and milk all the data that has accumulated
in Final Storage since the last visit.

3) Retrieve the data over some form of
telecommunications link, whether it be RF,
telephone, short haul modem, or satellite.
This can be performed under program
control or by regularly scheduled polling of
the dataloggers. Campbell Scientific's
Datalogger Support Software automates
this process.

Regardless of which method is used, the
retrieval of data from the datalogger does NOT
erase those data from Final Storage. The data
remain in the ring memory until:

They are written over by new data (Section 2.1)
Memory is reallocated or the CR510 is reset

(Section 1.5)
Table OV6.1-1 lists the instructions used with

the various methods of data retrieval.

TABLE OV6.1-1. Data Retrieval Methods and Related Instructions

Method Instruction/Mode Section in Manual

Storage Module Instruction 96 4.1, 12

∗8
∗9

Telecommunications Telecommunications

Commands 5

Instruction 97 12
Printer or other Instruction 96 4.1, 12
Serial device

∗8

4.2

4.5

4.2

OV-16

S

DATALOGGER

SC12 CABLES

CR510 OVERVIEW

DSP4

HEADS UP

DISPLAY

SM192/716
STORAGE
MODULE

STORAGE
MODULE
OR CARD
BROUGHT
FROM THE
FIELD TO
THE
COMPUTER

SM192/716

STORAGE
MODULES

CSM1

CSM1

MD9
MULTIDROP
INTERFACE

COAXIAL
CABLE

MD9
MULTIDROP
INTERFACE

SC12 CABLE

SC532

RS-232

INTERFACE

COMPUTER

ASYNCHRONOUS SERIAL
COMMUNICATIONS PO RT

RF95 RF

RF

MODEM

MODEM

RF

RF100/RF200

TRANSCEIVER

TRANSCEIVER

W/ANTENNA

W/ ANTENNA

& CABLE

& CABLE

RF

RF100/RF200

TRANSCEIVER

TRANSCEIVER

W/ANTENNA

W/ ANTENNA &

& CABLE

CABLE

SC12 CABLE

RF232 RF

RF

BASE

BASE

STATION

STATION

SC32A

RS-232

INTERFACE

INTERFACE

SRM-5A RAD

SRM-6A RAD

SHORTHAUL

SHORTHAUL

MODEM

MODEM

2 TWISTED

PAIR WIRES

UP TO 5 MI.

SRM-5A RAD

SRM-6A RAD

SHORTHAUL

SHORTHAUL

MODEM

MODEM

RS-232

RS-232

CABLE

CABLE

SC932

COM200

DC112

PHONE

PHONE

MODEM

MODEM

PHONE
LINE

HAYES

COMPATIBLE

PHONE

MODEM

COM100

DC1765

CELLULAR

CELLULAR

PHONE

PHONE

NOTES: 1. ADDITIONAL METHODS OF DATA RETRIEVAL ARE:

A. SATELLITE TRANSMISSION
B. DIRECT DUMP TO PRINTER
C. VOICE PHONE MODEM TO VOICE PHONE OR PC WITH HAYES COMPATIBLE

PHONE MODEM

2. THE DSP4 HEADS UP DISPLAY ALLOWS THE USER TO VIEW DATA IN INPUT
STORAGE. ALSO BUFFERS FINAL STORAGE DATA AND WRITES IT TO PRINTER
OR STORAGE MODULE.

3. ALL CAMPBELL SCIENTIFIC RS-232 INTERFACES HAVE A FEMALE 25 PIN RS-232
CONNECTOR.

FIGURE OV6.1-1. Data Retrieval Hardware Options

OV-17

CR510 OVERVIEW

OV7. SPECIFICATIONS

Electrical specifications are valid over a -25° to +50°C range unless otherwise specified; non-condensing environment
required. To maintain electrical specifications, yearly calibrations are recommended.

PROGRAM EXECUTION RATE

System tasks initiated in sync with real-time up
to 64 Hz. One measurement with data transfer is
possible at this rate without interruption.

ANALOG INPUTS

NUMBER OF CHANNELS: 2 differential or 4

single-ended, individually configured.

RANGE AND RESOLUTION:

Full Scale Resolution (µV)

Input Range (mV) Diff

±2500 333 666

±250 33.3 66.6

±25 3.33 6.66
±7.5 1.00 2.00
±2.5 0.33 0.66

INPUT SAMPLE RATES: Includes the measurement

time and conversion to engineering units. The
fast and slow measurements integrate the signal
for 0.25 and 2.72 ms, respectively. Differential
measurements incorporate two integrations with
reversed input polarities to reduce thermal offset
and common mode errors.

Fast differential voltage: 4.2 ms
Slow differential voltage: 9.2 ms
Differential with 60 Hz rejection: 25.9 ms

ACCURACY: ±0.1% of FSR (-25° to 50°C);

INPUT NOISE VOLTAGE (for ±2.5 mV range):

COMMON MODE RANGE: ±2.5 V
DC COMMON MODE REJECTION: > 140 dB
NORMAL MODE REJECTION: 70 dB (60 Hz with

INPUT CURRENT: ±9 nA maximum
INPUT RESISTANCE: 20 Gohms typical

±0.05% of FSR (0° to 40°C);
e.g., ±0.1% FSR = ±5.0 mV for ±2500
mV range

Fast differential: 0.82 µV rms
Slow differential: 0.25 µV rms
Differential with

60 Hz rejection: 0.18 µV rms

slow differential measurement)

erential Single-Ended

ANALOG OUTPUTS

DESCRIPTION: 2 switched excitations, active only

during measurement, one at a time.
RANGE: ±2.5 V
RESOLUTION: 0.67 mV
ACCURACY: ±2.5 mV (0° to 40°C);

CURRENT SOURCING: 25 mA
CURRENT SINKING: 25 mA
FREQUENCY SWEEP FUNCTION: The switched

±5 mV (-25° to 50°C)

outputs provide a programmable swept frequency,

0 to 2.5 V square wave for exciting vibrating wire

transducers.

RESISTANCE MEASUREMENTS

MEASUREMENT TYPES: The CR510 provides

ratiometric bridge measurements of 4- and 6-wire

full bridge, and 2-, 3-, and 4-wire half bridges.

Precise dual polarity excitation using any of the

switched outputs eliminates dc errors.

Conductivity measurements use a dual polarity

0.75 ms excitation to minimize polarization errors.

ACCURACY: ±0.02% of FSR plus bridge errors.

PERIOD AVERAGING MEASUREMENTS

DEFINITION: The average period for a single cycle is

determined by measuring the duration of a speci­fied number of cycles. Any of the 4 single-ended
analog input channels can be used. Signal atten­tuation and ac coupling is typically required.

INPUT FREQUENCY RANGE:

Signal peak-to-peak

Min. Max. Pulse w. Freq.

500 mV 5.0 V 2.5 µs 200 kHz

10 mV 2.0 V 10 µs 50 kHz

5 mV 2.0 V 62 µs 8 kHz
2 mV 2.0 V 100 µs 5 kHz

RESOLUTION: 35 ns divided by the number of

cycles measured
ACCURACY: ±0.03% of reading
TIME REQUIRED FOR MEASUREMENT: Signal

period multiplied by the number of cycles

measured plus 1.5 cycles + 2 ms.

1

Min. Max

2

PULSE COUNTERS

NUMBER OF CHANNELS: 2 eight-bit or 1 sixteen-

bit; software selectable as switch closure, high

frequency pulse, or low-level ac modes. An addi-

tional channel (C2/P3) can be software configured

to read switch closures at rates up to 40 Hz.
MAXIMUM COUNT RATE: 16 kHz, eight-bit counter;

400 kHz, sixteen-bit counter. Channels are

scanned at 8 or 64 Hz (software selectable).
SWITCH CLOSURE MODE:

Minimum Switch Closed Time: 5 ms

Minimum Switch Open Time: 6 ms

Maximum Bounce Time: 1 ms open

without being counted

HIGH FREQUENCY PULSE MODE:

Minimum Pulse Width: 1.2 µs

Maximum Input Frequency: 400 kHz

Maximum Input Voltage: ±20 V

Voltage Thresholds: Count upon transition

from below 1.5 V to above 3.5 V at low frequen-

cies. Larger input transitions are required at high

frequencies because of input filter with 1.2 µs time

constant. Signals up to 400 kHz will be counted if

centered around +2.5 V with deviations ‡ – 2.5 V

for ‡ 1.2 µs.
LOW LEVEL AC MODE:

(Typical of magnetic pulse flow transducers or

other low voltage, sine wave outputs.)

Input Hysteresis: 14 mV

Maximum ac Input Voltage: ±20 V

Minimum ac Input Voltage:

(Sine wave mV rms)* Range (Hz)

20 1 to 1000

200 0.5 to 10,000

*16-bit config. or 64 Hz scan req’d for freq. > 2048 Hz

1000 0.3 to 16,000

DIGITAL I/O PORTS

DESCRIPTION: Port C1 is software selectable as a

binary input, control output, or as an SDI-12 port.

Port C2/P3 is input only and can be software con-

figured as an SDI-12 port, a binary input, or as a

switch closure counter (40 Hz max).
OUTPUT VOLTAGES (no load): high 5.0 V ±0.1 V;

low < 0.1 V
OUTPUT RESISTANCE: 500 ohms
INPUT STATE: high 3.0 to 5.5 V; low -0.5 to 0.8 V

INPUT RESISTANCE: 100 kohms

SDI-12 INTERFACE STANDARD

DESCRIPTION: Digital I/O Ports C1-C2 support

SDI-12 asynchronous communication; up to ten
SDI-12 sensors can be connected to each port.
Meets SDI-12 standard Version 1.2 for datalogger
and sensor modes.

EMI and ESD PROTECTION

The CR510 is encased in metal and incorporates EMI
filtering on all inputs and outputs. Gas discharge
tubes provide robust ESD protection on all terminal
block inputs and outputs. The following European
standards apply.

EMC tested and conforms to BS EN61326:1998.
Details of performance criteria applied are available

upon request.

CPU AND INTERFACE

PROCESSOR: Hitachi 6303.
PROGRAM STORAGE: Up to 16 kbytes for active

program; additional 16 kbytes for alternate
programs. Operating system stored in 128 kbytes
Flash memory.

DATA STORAGE: 128 kbytes SRAM standard

(approximately 62,000 values). Additional
2 Mbytes Flash available as an option.

OPTIONAL KEYBOARD DISPLAY: 8 digit LCD

(0.5" digits).

PERIPHERAL INTERFACE: 9 pin D-type

connector for keyboard display, storage module,
modem, printer, card storage module, and
RS-232 adapter.

BAUD RATES: Selectable at 300, 1200, and 9600,

76,800 for certain synchronous devices. ASCII
communication protocol is one start bit, one stop
bit, eight data bits (no parity).

CLOCK ACCURACY: ±1 minute per month

SYSTEM POWER REQUIREMENTS

VOLTAGE: 9.6 to 16 Vdc
TYPICAL CURRENT DRAIN: 1.3 mA quiescent,

13 mA during processing, and 46 mA during
analog measurement.

BATTERIES: Any 12 V battery can be connected as

a primary power source. Several power supply
options are available from Campbell Scientific.
The model CR2430 lithium battery for clock and
SRAM backup has a capacity of 270 mAhr.

PHYSICAL SPECIFICATIONS

SIZE: 8.4" x 1.5" x 3.9" (21.3 cm x 3.8 cm x 9.9 cm).

Additional clearance required for serial cable and
sensor leads.

WEIGHT: 15 oz. (425 g)

WARRANTY

Three years against defects in materials
and workmanship.

We recommend that you confirm system

configuration and critical specifications with

Campbell Scientific before purchase.

OV-18

Copyright © 1999, 2001
Campbell Scientific, Inc.
Printed September 2001

SECTION 1. FUNCTIONAL MODES

1.1 DATALOGGER PROGRAMS ­3, AND

∗∗∗∗

Data acquisition and processing functions are
controlled by user-entered instructions
contained in program tables. Programming can
be separated into 2 tables, each having its own
user-entered execution interval. A third table is
available for programming subroutines which
may be called by instructions in Tables 1 or 2 or
by a special interrupt. The ∗1 and ∗2 Modes
are used to access Tables 1 and 2. The ∗3
Mode is used to access Subroutine Table 3.

The ∗4 Mode Table is a table of values used in
the program that someone can change while
the rest of the program is protected. These
values may be used for sensor calibrations or to
select optional sensors. The ∗4 Table is only
available when a special program created by
EDLOG is loaded in the CR510.

When a program table is first entered, the
display shows the table number in the ID field
and 00 in the data field. Keying an "A" will
advance the editor to the execution interval. If
there is an existing program in the table, keying
an instruction location number prior to "A" will
advance directly to the instruction (e.g., 5 will
advance to the fifth instruction in the table).

1.1.1 EXECUTION INTERVAL

The execution interval is entered in units of
seconds as follows:

4 MODES

∗∗∗∗

1,

2,

∗∗∗∗

∗∗∗∗

offset, and the result placed in Input Storage).
Additional processing requires extra time. The
throughput rate is the rate at which a
measurement can be made and the resulting
value stored in Final Storage. The maximum
throughput rate for fast single-ended
measurements with standard software is 192
measurements per second (12 measurements
repeated 16 times per second).

If the specified execution interval for a table is
less than the time required to process that
table, the CR510 finishes processing the table
and waits for the next occurrence of the
execution interval before again initiating the
table (i.e., when the execution interval has
elapsed and the table is still executing, that
execution is skipped). Since no advantage is
gained in the rate of execution with this
situation, it should be avoided by specifying an
execution interval adequate for the table
processing time.

NOTE: Whenever the processing time of
the user's program exceeds a table's
execution interval, an error is logged in
memory. The number of overrun errors
can be displayed and reset in the ∗B mode
(Section 1.6) or using the Telecommunica­tions A command (Section 5.1). An overrun
will also cause decimal points to appear on
both sides of the sixth digit of the CR10KD.
The decimal points will not appear around
the G in LOG if the ∗0 Mode is entered

before the overrun occurs.

1/8 ....31.875 seconds, in multiples of 1/8 (0.125)

32 .....8191 seconds, in multiples of 1 second

Execution of the table is repeated at the rate
determined by this entry. The table will not be
executed if 0 is entered. Entries less than 32
seconds will be rounded to a valid interval if
they are within 1/512 (0.00195) second of a
valid interval, otherwise error E41 will be
displayed. Entries greater than 32 seconds are
rounded to the nearest second.

The sample rate for a CR510 measurement is
the rate at which the measurement instruction
can be executed (i.e., the measurement made,
scaled with the instruction's multiplier and

In some cases, the processing time may exceed
the execution interval only when the Output Flag is
set and extra time is consumed by final Output
Processing. This may be acceptable. For
example, suppose it is desired to sample some
phenomena every 0.125 seconds and output
processed data every 10 minutes. The processing
time of the table which does this is less than 0.125
seconds except when output occurs (every 10
minutes). With final output the processing time is
1 second. With the execution interval set at 0.125
seconds, and a one second lag between samples
once every 10 minutes, 8 measurements out of
4800 (.17%) are missed: an acceptable statistical
error for most populations.

1-1

SECTION 1. FUNCTIONAL MODES

1.1.2 SUBROUTINES

Table 3 is used to enter subroutines which may
be called with Program Control Instructions in
Tables 1 and 2 or other subroutines. The group
of instructions which form a subroutine starts
with Instruction 85, Label Subroutine, and ends
with Instruction 95, End (Section 12).

Subroutine 98 has the unique capability of being
executed when port 2 goes high. This
subroutine will interrupt Tables 1 and 2 (Section

1.1.3) when port 2 goes high. When the port
goes high, the processor awakes within a few
microseconds. The port triggers on the rising
edge (i.e., when it goes from low to high). If the
port stays high, the subroutine is not called
again.

1.1.3 TABLE PRIORITY/INTERRUPTS

Table 1 execution has priority over Table 2. If
Table 2 is being executed when it is time to
execute Table 1, Table 2 will be interrupted.
After Table 1 processing is completed, Table 2
processing resumes at the interruption point. If
the execution interval of Table 2 coincides with
Table 1, Table 1 is executed first, then Table 2.

Interrupts by Table 1 are not allowed in the
middle of an instruction or while output to Final
Storage is in process (flag 0 is set high). The
interrupt occurs as soon as the instruction is
completed or flag 0 is set low.

Subroutine 98 can be initiated by port 2 going
high (Section 1.1.2), can interrupt either Table 1
or 2 or can occur when neither is being
executed. This subroutine can interrupt a table
while the Output Flag is set. When the port
goes high during the execution of a table, the
instruction being executed is completed before
the subroutine is run (i.e., as if the subroutine
was called by the next instruction).

The priority is Subroutine 98, Table 1, Table 2.
If the interrupt subroutine started when neither
table was running, then neither table can
interrupt it.

While subroutine 98 is being executed as a
result of port 2 going high, that port interrupt is
disabled (i.e., the subroutine must be completed
before the port going high will have any effect).

1.1.4 ∗∗∗∗4 PARAMETER ENTRY TABLE

The ∗4 mode is a table with up to one hundred
values. Each value corresponds to an
instruction parameter in the datalogger
program. When the datalogger compiles the
program, values in the ∗4 table are transferred
to the corresponding instruction parameter.
The datalogger program must be created using
EDLOG which allows instruction parameters to
be assigned to the ∗4 table.

In a network of datalogger stations, the ∗4 table
can be used to simplify site customization and
the procedure of information entry. Once a
generalized program is developed, application
specific details, e.g., sensor calibration, can be
entered without accessing the ∗1 and ∗2
program tables or the ∗3 subroutine table.

ASSIGNING PARAMETERS TO ∗∗∗∗4 - EDLOG

The only way to implement the ∗4 mode is
through EDLOG. The datalogger program is
generated in EDLOG in the normal way.

To assign a parameter to a ∗4 location, position
the cursor on the desired parameter and press
the "@" key. EDLOG then prompts for the
location number in the ∗4 table to be assigned
to the associated parameter. After a valid
number is entered, EDLOG marks the
parameter with "@@nn" to the right of the
parameter description, where "nn" is the ∗4
location number.

Older versions of EDLOG (prior to DOS Version

6.0) may not support the ∗4 mode or may
require that the support be enabled. To enable
the ∗4 mode press the F5 key followed by the
"@" key while in EDLOG's edit mode. "F5=∗4
List" is displayed at the top of the screen
indicating that EDLOG's ∗4 feature is active.
Subsequent use of the F5 key displays a list
indicating which ∗4 locations are in use. If your
copy of EDLOG is earlier than 6.0 and it does
not display "F5=∗4 List", it is likely that that
version of EDLOG does not support the ∗4
mode. Please contact Campbell Scientific for
details of an upgrade.

Any program parameter or execution interval
can be marked for inclusion in the table, as
illustrated below.

1-2

SECTION 1. FUNCTIONAL MODES

PROGRAM

* Table 1 Program

01: 0.0 Execution Interval

(seconds) @@0

01: Volts (SE) (P1)

1: 1 Reps
2: 1 ±2.5 mV Slow Range
3: 1 SE Channel
4: 1 Loc [ _________ ]
5: 1 Mult @@1
6: 0 Offset @@2

In the above example, ∗4 location 0 is assigned
to the program table execution interval, and
locations 1 and 2 to the multiplier and offset of
the measurement instruction. Note that a
default execution interval of zero means the
program will not execute until an alternative
interval is entered in location 00 of the ∗4 mode.
A default multiplier and offset of 1 and 0 means
that the measurement value is in units of
millivolts. A different multiplier and offset can
be entered in ∗4 locations 1 and 2, respectively.

A ∗4 location can be used in only one program
parameter. For example, ∗4 locations 0, 1, and
2 used in the example cannot be reused in
another instruction in the same program.

If the ∗4 feature is enabled in EDLOG when
printing a program to a printer or disk file, the ∗4
list is printed at the end of the file.

To enter a value in a ∗4 location, advance to the
desired location, key in the number and enter it
by pressing the "A" key. The value is not
entered if the "A" key is not pressed.

Entering a new value causes the datalogger to
stop logging. Logging resumes when the
program is compiled. Upon compiling, all
current ∗4 values are incorporated into the
program. For this reason, whenever changes
are made in the ∗4 mode, make sure that all ∗4
values are correct before exiting the ∗4 mode.

Removing or adding an instruction to a program
residing in the datalogger disables the ∗4 mode.
An instruction parameter may be edited without
any adverse affect. If the ∗4 mode is disabled,
it may be reactivated by downloading the
program to the datalogger or, if the program
was saved to Flash storage, retrieving the
program from the stored program area.

The ∗C mode (Section 1.7) may be used to
secure the datalogger program and the ∗4
mode entries. The lowest level of security
prevents access to the ∗1, ∗2, and ∗3 modes.
Higher levels of security block ∗4.

The CR510 will not respond to the ∗4 command
if any of the following conditions exist.

• the program that was downloaded does not
contain any ∗4 assignments.

Once the EDLOG created program has been
sent to the CR510, it can be saved in the Flash
memory program storage area using the ∗D
Mode (Section 1.8).

CHANGING VALUES IN ∗∗∗∗4 TABLE

Enter the ∗4 Mode by keying "∗4"; "04:00" is
then displayed. At this point it is possible to
jump to any valid ∗4 location by keying the
desired location number and pressing the A
key. For example, when the display shows
04:00 and the desired location is 80, key in the
number 80, press the A key and the display will
show "80:XXXXX." where XXXXX. is the value
stored in location 80. Pressing the "A" key
advances to the next ∗4 location, and the "B"
key backs up to the previous location. If a ∗4
location is not assigned in the datalogger
program, it can not be displayed in the ∗4 mode.

• a program that was downloaded has since
been hand edited.

• Security is blocking access to ∗4.

1.1.5 COMPILING A PROGRAM

When a program is first loaded, or if any
changes are made in the ∗1, ∗2, ∗3, ∗4, ∗A, or
∗C Modes, the program must be compiled
before it starts running. The compile function
checks for programming errors and optimizes
program information for use during program
execution. If errors are detected, the
appropriate error codes are indicated on the
display (Section 3.10). The compile function is
executed when the ∗0 , ∗6, or ∗B Modes are
entered and prior to saving a program listing in
the ∗D Mode. The compile function is only
executed after a program change has been
made and any subsequent use of any of these

1-3

SECTION 1. FUNCTIONAL MODES

modes will return to the mode without
recompiling.

When the ∗0 or ∗B Mode is used to compile, all
output ports and flags are set low, the timer is
reset, and data values contained in Input and
Intermediate Storage are reset to zero.

When the ∗6 Mode is used to compile data
values contained in Input Storage, the state of
flags, control ports, and the timer (Instruction

26) are unaltered. Compiling always zeros
Intermediate Storage.

1.2 SETTING AND DISPLAYING THE
CLOCK -

The ∗5 Mode is used to display or set time.
When "∗5" is entered, time is displayed. It is
updated approximately once a second or longer
depending on the rate and degree of data
collection and processing taking place. The
sequence of time parameters displayed in the
∗5 Mode is given in Table 1.2-1.

To set the year, day, or hours and minutes,
enter the ∗5 Mode and advance to display the
appropriate value. Key in the desired number
and enter the value by keying "A". When a new
value for hours and minutes is entered, the
seconds are set to zero and current time is
again displayed. To exit the ∗5 Mode, key "∗"
and the mode you wish to enter.

When the time is changed, a partial recompile
is done automatically to synchronize the
program with real time.

Changing time affects the output and execution
intervals in which time is changed. Because
time can only be set with a 1 second resolution,
execution intervals of 1 second or less remain
constant. Averaged values will still be accurate,
though the interval may have a different number
of samples than normal. Totalized values will
reflect the different number of samples. The
pulse count instruction will use the previous
interval's value if an option has been selected to
discard odd intervals, otherwise it will use the
count accumulated in the interval.

5 MODE

∗∗∗∗

TABLE 1.2-1. Sequence of Time

Parameters in ∗∗∗∗5 Mode

Display

Key ID:DATA

5

∗

:HH:MM:SS Display current time

A
A

05:XXXX Display/enter year
05:XXXX Display/enter day of year

Description

1-365(366)

A

05:HH:MM: Display/enter

hours:minutes

1.3 DISPLAYING/ALTERING INPUT
MEMORY, FLAGS, AND PORTS ­MODE

The ∗6 Mode is used to display and/or change
Input Storage values and to toggle and display
user flags and ports. If the ∗6 Mode is entered
immediately following any changes in program
tables, the program will be compiled and run.

NOTE: Input Storage data and the state of
flags, control ports, and the timer
(Instruction 26) are UNALTERED
whenever program tables are altered and
recompiled with the ∗6 Mode. Compiling
always zeros Intermediate Storage.

TABLE 1.3-1. ∗∗∗∗6 Mode Commands

Key Action

A

B

C

D
0
#

1.3.1 DISPLAYING AND ALTERING INPUT STORAGE WITH THE KEYBOARD DISPLAY

When "∗6" is entered, the keyboard/display will
read "06:0000". One can advance to view the
value stored in input location 1 by keying "A".
To go directly to a specific location, key in the
location number before keying "A". For
example, to view the value contained in Input

Advance to next input location or
enter new value

Back-up to previous location
Change value in input location

(followed by keyed in value, then "A")
Display/alter user flags
Display/alter ports
Display current location and allow a

location number to be keyed in,
followed by "A" to jump to that
location

6

∗∗∗∗

1-4

SECTION 1. FUNCTIONAL MODES

Storage location 20, key in "*6 20 A". The ID
portion of the display shows the last 2 digits of
the location number. If the value stored in the
location being monitored is the result of a
program instruction, the value on the
keyboard/display will be the result of the most
recent scan and will be updated each time the
instruction is executed. When using the ∗6
Mode from a remote terminal, a number (any
number) must be sent before the value shown
will be updated.

Input locations can be used to store parameters
for use in computations. To store a value in a
location, or change the current value, key "C"
while monitoring the location, followed by the
desired number and "A". This number will be
saved once the program is recompiled.

If an algorithm requires parameters to be
manually modified during execution of the
Program without interruption of the Table
execution process, the ∗6 Mode can be used. (If
parameters will not need modification, it is better
to load them from the program using Instruction

30.) If initial parameter values are required to be
in place before program execution commences,
use Instruction 91 at the beginning of the
program table to prevent the execution until a
flag is set (see the next section). Initial
parameter values can be entered into input
locations using the ∗6 Mode C command. The
flag can then be set to enable the table(s).

If the program is altered and compiled with ∗0
Mode, all values previously entered via ∗6C will
be set to zero. To preserve ∗6C entered values,
compile in the ∗6 Mode after changing the
program.

1.3.2 DISPLAYING AND TOGGLING USE R FLAGS

If D is keyed while the CR510 is displaying a
location value, the current status of the user flags
will be displayed in the following format:
"00:010010". The characters represent the flags,
the left-most digit is Flag 1 and right most is Flag

8. A "0" indicates the flag is clear or “low” and a
"1" indicates the flag is set or “high”. In the above
example, Flags 4 and 7 are set. To toggle a flag,
simply press the corresponding number. To
return to displaying the input location, press "A".

Entering appropriate flag tests into the program
allows manual control of program execution.

For example, to manually start the execution of
Table 2: enter Instruction 91 as the first
instruction in Table 2. The first parameter is 25
(do if Flag 5 is low), the second parameter is 0,
go to end of program table. If Flag 5 is low, all
subsequent instructions in Table 2 will be
skipped. Flag 5 can be toggled from the ∗6
Mode, effectively starting and stopping the
execution of Table 2.

1.3.3 DISPLAYING AND TOGGLING PORTS

The status of the CR510 ports can be displayed
by hitting "0" while looking at an input location
(e.g., ∗6 A0). Ports are displayed left to right
as 0, 0, 0, 0, 0, 0, C2, C1 (exactly opposite to
the flags). A port configured as output can be
toggled by hitting its number while in the port
display mode. There is no effect on C2
because it is configured as an input only, or on
C1 when it is configured as input only.

On power up all ports are configured as inputs.
Instruction 20 is used to configure C1 as an
output. Port C1 can also be configured as an
output by any program control commands which
uses the port as an output (pulse, set high, set
low, toggle).

1.4 COMPILING AND LOGGING DATA ­0 MODE

∗∗∗∗

When the ∗0 Mode is entered after
programming the CR510, the program is
compiled and the display shows "LOG" followed
by the active program table numbers. The
display is not updated after entering ∗0.

NOTE: All output ports are set low, the
timer is reset, and data values in Input and
Intermediate Storage are RESET TO ZERO
whenever the program tables are altered
and the Program is recompiled with the ∗0
Mode. The same is true when the
programs are compiled with ∗B or ∗D.

To minimize current drain, the CR510 should be
left in the ∗0 Mode when logging data.

1.5 MEMORY ALLOCATION -

1.5.1 INTERNAL MEMORY

When powered up with the keyboard display
attached, the CR10KD displays HELLO while
performing a self check. The total system

A

∗∗∗∗

1-5

SECTION 1. FUNCTIONAL MODES

memory is then displayed in K bytes. The size
of memory can be displayed in the ∗B mode.

Input Storage is used to store the results of
Input/Output and Processing Instructions. The
values stored in input locations may be
displayed using the ∗6 Mode (Section 1.3).

Final Storage holds stored data for a
permanent record. Output Instructions store
data in Final Storage when the Output Flag is
set (Section 3.7). The data in Final Storage can
be monitored using the ∗7 Mode (Section 2.3).

Intermediate Storage is a scratch pad for
Output Processing Instructions. It is used to
store the results of intermediate calculations
necessary for averages, standard deviations,

histograms, etc. Intermediate Storage is not
accessible by the user.

Each Input or Intermediate Storage location
requires 4 bytes of memory. Each Final
Storage location requires 2 bytes of memory.
Low resolution data points require 1 Final
Storage location, and high resolution data
points require 2. Section 2 describes Final
Storage and data retrieval in detail.

Figure 1.5-1 lists the basic memory functions
and the amount of memory allotted to them.

1-6

SECTION 1. FUNCTIONAL MODES

Flash Memory

(EEPROM)

Total 128 Kbytes

Operating System

(96 Kbytes)

Active Program

(16 Kbytes)

Stored Programs

(16 Kbytes)

How it works:

The Operating System is loaded into
Flash Memory at the factory. System
Memory is used while the CR510 is
running for calculations, buffering data
and general operating tasks.

Any time a user loads a program into
the CR510, the program is compiled in
SRAM and stored in the Active
Program areas. If the CR510 is
powered off and then on, the Active
Program is loaded from Flash and run.

The Active Program is run in SRAM to
maximize speed. The program
accesses Input Storage and
Intermediate Storage and stores data
into Final Storage for later retrieval by
the user.

The Active Program can be copied into
the Stored Programs area. While 98
program "names" are available, the
number of programs stored is limited
by the available memory. Stored
programs can be retrieved to become
the active program. While programs
are stored one at a time, all stored
programs must be erased at once. That
is because the flash memory can only
be written to once before it must be
erased and can only be erased in 16
Kbytes blocks.

SRAM

Total 128 Kbytes

System Memory

(4096 Bytes)

Active Program

(default 2048 Bytes)

Input Storage

(default 28 locations,
112 bytes)

Intermediate Storage

(default 64 locations,
256 bytes)

Final Storage Area 1

(default 62,280
locations, 124,560
bytes)

Final Storage Area 2

(default 0 locations,
0 bytes)

Optional

Flash EEPROM

With the Optional Flash Memory, up to
2 Mbytes of additional memory can be
added to increase Final Storage by
another 524,288 data values per
Mbyte. The user can allocate this extra
memory to any combination of Area 1
or Area 2.

(Memory Areas separated by dashed
lines:
can be re-sized by the user.)

FIGURE 1.5-1. CR510 Memory

Final Storage Area 1

and/or

Final Storage Area 2

(

Additional

524,288

locations per Mbyte)

1-7

SECTION 1. FUNCTIONAL MODES

1.5.2 ∗∗∗∗A MODE

The ∗A Mode is used to 1) determine the number of
locations allocated to Input Storage, Intermediate
Storage, Final Storage Area 2, Final Storage Area
1, and Program Memory; 2) repartition this memory;

3) check the number of bytes remaining in Program
memory; 4) erase Final Storage; and 5) to
completely reset the datalogger.

A second Final Storage area (Storage Area 2)
can be allocated in the ∗A Mode. On power up,
the number of locations allocated for Storage
Area 2 defaults to 0. Final Storage Area 1 is the
source from which memory is taken when Input,
Intermediate, Final Storage Area 2, or program
memories are increased. When they are
reduced, Final Storage Area 1 memory is
increased. Allocation of Input and Intermediate
Storage locations does NOT change Final
Storage Area 2.

With the Flash EEPROM 1 or 2 meg. expanded
memory options, the boundary between Area 1
and Area 2 must lie between 32 K location
sectors. Entries for Area 2 greater than 32,769
locations will be rounded up to the next boundary.

When ∗A is entered, the first number displayed
is the number of memory locations allocated to
Input Storage. The "A" key is used to advance
through the next 6 windows. Table 1.5-2
describes what the values in the ∗A Mode
represent.

At the reset, the memory allocation defaults to
the values in Figure 1.5-1. The size of Final
Storage is determined by the size of memory
installed.

The sizes of Input, Intermediate, Final Storage
Area 2, and Program Memory may be altered by
keying in the desired value and entering it by
keying "A". One Input or Intermediate Storage
location can be exchanged for two Final Storage
locations. The size of Final Storage Area 1 will be
adjusted automatically.

The maximum size of Input and Intermediate
Storage and the minimum size of Final Storage
are determined by the memory installed (Figure

1.5-1). A minimum 28 Input location and one
Final Storage Area 1 location will ALWAYS be
retained. The size of Intermediate Storage may
be reduced to 0.

Keyboard Display
Entry ID: Data

A

∗

A

A

A

A

A

01: XXXX Input Storage Locations (minimum of 28, maximum limited by

02: XXXX Intermediate Storage Locations (maximum limited by available

03: XXXXX Final Storage Area 2 Locations (minimum of 0, maximum

04: XXXXX Final Storage Area 1 Locations (minimum of 1). This number is

05: Bytes allocated for user program. The number of bytes to

06: Bytes free in program memory. The user cannot change this

TABLE 1.5-2. Description of ∗∗∗∗A Mode Data

Description of Data

available memory and constraints on Final Storage). This value
can be changed by keying in the desired number.

memory and constraints on Input and Final Storage). This value
can be changed by keying in the desired number. Enter 0 and
the CR510 will assign the exact number needed. Entering 0
will also result in the CR510 erasing all data whenever the
program is changed and compiled.

limited by available memory). Changing this number
automatically reallocates Final Storage Area 1.

automatically altered when the memory allocation for Program,
Input, Intermediate, or Final Storage Area 2 is changed.

assign to program memory can be keyed in to change the size of
program memory. Changing the size of program memory results
in all data being erased. Enter 0 and the CR510 will assign the
exact number needed. Entering 0 will also result in the CR510
erasing all data whenever the program is changed and compiled.

Key in 98765 to completely reset datalogger.

window. It is a function of window 5 and the program.

1-8

SECTION 1. FUNCTIONAL MODES

After repartitioning memory, the program must be
recompiled. Compiling erases Intermediate
Storage. Compiling with ∗0 erases Input Storage;
compiling with ∗6 leaves Input Storage unaltered.

If Intermediate Storage size is too small to
accommodate the programs or instructions
entered, the "E:04" ERROR CODE will be
displayed in the ∗0, ∗6, and ∗B Modes. The
user may remove this error code by entering a
larger value for Intermediate Storage size.
Intermediate Storage and Program Memory can
be automatically allocated by entering 0 for their
size. When automatic allocation is used, all
data are erased any time the program is
exchanged and recompiled. Final Storage size
is maximized by limiting Intermediate Storage
and Program Memory to the minimum
necessary. The size of Final Storage and the
rate at which data are stored determines how
long it will take for Final Storage to fill, at which
point new data will write over old.

Intermediate Storage and Final Storage are
erased when memory is repartitioned. This
feature may be used to clear memory
without altering programming. The number
of locations (Windows 1-4) does not actually
need to be changed; the same value can be
keyed in and entered.

ENTERING 98765 for the number of bytes to
allocate for program memory (5th Window)
COMPLETELY RESETS THE CR510. All

memory is erased including any stored programs
and memory is checked. Memory allocation
returns to the default. The reset operation
requires approximately 1 minute for a CR510, 5
minutes for a CR510-1M, and 10 minutes for a
CR510-2M. Please be patient while the reset

takes place; if the CR510 is turned off in the
middle of a reset, it will perform the reset the
next time it is powered up.

1.6 MEMORY TESTING AND SYSTEM

STATUS -

The ∗B Mode is used to check the status of the
program’s operating system and lithium battery.
Table 1.6-1 describes what the values seen in
the ∗B Mode represent.

A signature is a number which is a function of
the data and the sequence of data in memory.
It is derived using an algorithm which assures a

99.998% probability that if either the data or its
sequence changes, the signature changes.
The signature of the program memory is used
to determine if the program tables have been
altered. During the self check on reset, the
signature computed for the Operating Sytem
(OS) is compared with a stored signature to
determine if a failure has occurred. The
algorithm used to calculate the signature is
described in Appendix C.

NOTE: Instruction 19 calculates one
signature for the program
System. Because this is a combined
signature, it is not the same as the
signatures in Windows 1 or 2.

The contents of windows 6 and 7, Operating System
(OS) version and version revision, are helpful in
determining what OS is in the datalogger. As
different versions are released, there may be
operational differences. When calling Campbell

Scientific for datalogger assistance, please have
these numbers available.

B

∗∗∗∗

the Operating

and

1-9

SECTION 1. FUNCTIONAL MODES

TABLE 1.6-1. Description of ∗∗∗∗B Mode Data

Keyboard Display
Entry ID: Data

B

∗

A
A
A
A
A
A
A
A
A
A

01: XXXXX Program memory Signature. The value is dependent upon the

02: XXXXX Operating System (OS) Signature
03: XXXXX Memory Size, Kbytes (Flash + SRAM)
04: XX Number of E08 occurrences (Key in 88 to reset)
05: XX Number of overrun occurrences (Key in 88 to reset)
06: X.XXXX Operating System version number
07: XXXX. Version revision number

08: X.XXXX Lithium battery voltage (measured daily)

09: XX Low 12 V battery detect counter (Key in 88 to reset)
10: XX Extended memory error counter (Key in 88 to reset)
11: X.XXXX Extended Memory time of erase, seconds

Description of Data

programming entered and memory allotment. If the program has
not been previously compiled, it will be compiled and run.

TABLE 1.7-1. ∗∗∗∗C Mode Entries

Keyboard Display
Entry ID: Data

C

∗

A
A

01:XXXX Non-zero password blocks entry to ∗1, ∗2, ∗3, ∗A, and ∗D

02:XXXX Non-zero password blocks ∗4, ∗5, and ∗6 except for display.
03:XXXX Non-zero password blocks ∗5, ∗6, ∗7, ∗8, ∗9, ∗B, and all

Keyboard Display
Entry ID: Data

C

∗

A

12:0000 Enter password. If correct, security is temporarily unlocked

01:XX Level to which security has been disabled.

SECURITY DISABLED

Description

Modes.

telecommunications commands except A, L, N, and E.

SECURITY ENABLED

Description

through that level.

0 -- Password 1 entered (everything unlocked)
1 -- Password 2 entered
2 -- Password 3 entered

1-10

SECTION 1. FUNCTIONAL MODES

1.7

C MODE -- SECURITY

∗∗∗∗

The ∗C Mode is used to block access to the
user's program information and certain CR510
functions. There are 3 levels of security, each
with its own 4 digit password. Setting a
password to a non-zero value "locks" the
functions secured at that level. The password
must subsequently be entered to temporarily
unlock security through that level. Passwords
are part of the program. If security is enabled in
the active program, it is enabled as soon as the
program is run when the CR510 is powered up.

When security is disabled, ∗C will advance
directly to the window containing the first
password. A non-zero password must be
entered in order to advance to the next window.
Leaving a password 0, or entering 0 for the
password disables that and subsequent levels
of security.

Security may be temporarily disabled by
entering a password in the ∗C Mode or using
the telecommunications L command (Section

5.1). The password entered determines what
operations are unlocked (e.g., entering
password 2 unlocks the functions secured by
passwords 2 and 3). Password 1 (everything
unlocked) must be entered before any
passwords can be altered.

When security is temporarily disabled in the ∗C
Mode, entering ∗0 will automatically re-enable
security to the level determined by the
passwords entered.

The telecommunications L command
temporarily changes the security level. After
hanging up, security is reset.

1.8

D MODE -- SAVE OR LOAD

∗∗∗∗

PROGRAM

The ∗D Mode is used to save or load CR510
programs, to set the degree to which memory is
cleared on powerup, to set the datalogger ID,
and to set communication to full or half duplex.

Programs (∗1, ∗2, ∗3, ∗4, ∗A, ∗C, and ∗D Mode
data) may be stored to and from computers,
internal flash memory, and Storage Modules.
Several programs can be stored in the CR510
Flash Memory and later recalled and run using
the ∗D Mode or Instruction 111.

Campbell Scientific’s datalogger support software
automatically makes use of the ∗D Mode to upload
and download programs from a computer.
Appendix C gives some additional information on
Commands 1 and 2 that are used for these
operations.

When "∗D" is keyed in, the CR510 will display
"13:00". A command (Table 1.8-1) is entered
by keying the command number and "A".

TABLE 1.8-1. ∗∗∗∗D Mode Commands

Command Description

1 Send (Print) ASCII Program
2 Load ASCII Program, ∗0 Compile
2-- Load ASCII Program, ∗6 Compile
6 Store Program in Flash
7 Load Program from Flash
7N Save/Load/Clear Program from

Storage Module N
8 Set Datalogger ID
9 Set Full/Half Duplex
10 Set Powerup Options

If the CR510 program has not been compiled
when the command to save a program is entered,
it will be compiled before the program is saved.
When a program is loaded, it is immediately
compiled and run. When a command is complete,
"13:0000" is displayed; ∗D must be entered again
before another command can be given.

TABLE 1.8-2. Progr am Load Error Codes

E 94 Program Storage Area full
E 95 Program does not exist in flash
E 96 Storage Module not connected or

wrong address
E 97 Data not encountered within 30 sec.
E 98 Uncorrectable errors detected
E 99 Wrong type of file or Editor Error

1.8.1 INTERNAL FLASH PROGRAM STORAGE

Several programs can be stored in the CR510
Flash Memory and later recalled and run using
the ∗D Mode. The Flash Electrically Erasable
Programmable Read Only Memory is non­volatile memory that can only be erased in 16K
blocks. The CR510 has 128K of Flash
EEPROM memory, one 16K block is reserved
for storing extra programs.

When a program is loaded and compiled, it is
saved as the active program. The active

1-11

SECTION 1. FUNCTIONAL MODES

program will be automatically loaded and run
when the CR510 is powered up. (If a Storage
Module with a program 8 is connected when the
CR510 powers-up, the Storage Module program
8 will be loaded into the CR510 and become the
active program.)

The active program can be stored in internal
flash memory program storage with ∗D
command 6 (Table 1.8-3). Programs can be
retrieved with ∗D command 7 (Table 1.8-4).

TABLE 1.8-3 Storing Program in

Internal Flash

Key entry Display

∗D 13:00
6A 06:00

You may now enter one of the following options:

xxA Save active program as

number xx, xx may be 1-98.
A Scroll forward and
B backward through saved

program numbers. The

numbers are displayed in the

order saved.
99A99A Clear all saved programs.
0A Display number of bytes free in

saved program area.

TABLE 1.8-4 Retrieving a Program from

Internal Flash

Key entry Display

∗D 13:00
7A 07:00

You may now enter one of the following options:

xxA Retrieve program number xx

(the most recent xx saved). To

have the program compile like

∗6 (no resetting of input

locations, flags, or ports) press

C (xx--) before A.
0A Erase active program (i.e., load a

blank program; memory allocation

and Final Storage are reset).
A Scroll forward and
B backward through saved

program numbers.

Scrolling through the program names begins
with the oldest program. "A" advances to the
next newer program, "B" backs up to the next
older program. While scrolling, at any time
typing in a number (xxA) will cause a save or a
retrieve operation.

Each program saved takes up the memory
required for the program + 6 bytes.

Flash memory can only be written to once
before being erased. Because it can only be
erased in 16K blocks, if one stored program is
to be erased, all must be erased. To allow
revising a program and storing it with the same
number (name) as an earlier version, the same
number can be used by more than one saved
program. When retrieving a program, the
programs are searched beginning with the last
program saved; the most recently saved version
will be retrieved. An older program with a
duplicate name cannot be retrieved. When the
flash program memory is full, all programs must
be erased before any more can be added (error
94 will be displayed).

1.8.2 PROGRAM TRANSFER WITH STORAGE MODULE

Storage Modules can store up to eight separate
programs. The Storage Module and
Keyboard/Display or Modem/Terminal must both
be connected to the CR510. After keying ∗D, the
command 7N, is entered (N is the Storage
Module address 1-8, Section 4.4.1). Address 1
will work with any Storage Module address; the
CR510 will search for the lowest address Storage
Module that is connected. The command to
save, load, or clear a program and the program
number (Table 1.8-5) is entered. After the
operation is finished "13:0000" is displayed. Error
96 indicates that the Storage Module is not
connected or the wrong address was given.

1-12

SECTION 1. FUNCTIONAL MODES

TABLE 1.8-5 Transferring a Program using a

Storage Module

Key entry Display

∗D 13:00
7NA 7N:00 (N is Storage Module

address 1-8)

You may now enter one of the following options:

1x Save Program x to Storage

Module (x = 1-8)

2x Load Program x from Storage

Module (x = 1-8)

3x Erase Program x in Storage

Module (x = 1-8)

The datalogger can be programmed on power­up using a Storage Module. If a program is
stored as program number 8, and the Storage
Module is connected to the datalogger I/O at
power-up, program number 8 is automatically
loaded into the active program area of the
datalogger and run.

1.8.3 FULL/HALF DUPLE X

The *D Mode can also be used to set
communications to full or half duplex. The default
is full duplex, which works best in most situations.

1.8.4 SET DATALOGGER ID

Command 8 is used to set the datalogger ID.
The ID can be moved to an input location with
Instruction 117 and can then be sampled as
part of the data.

TABLE 1.8-7 Setting Datalogger ID

Key Entry Display

∗D 13:00
8A 08:0XXX

Where XXX are 0s or the current ID. You may
now key in the ID (1-254, excluding 13).

1.8.5 SETTING POWERUP OPTIONS

Setting options for the Program on Powerup
allows the user to specify what information to
retain from when the datalogger was last on.
This allows Flag/Port status, the User Timer,
and the Input/Intermediate Storage to be
cleared or not cleared.

Table 1.8-8. Setting Powerup Options

Key entry Display

∗D 13:00
10A 10:0X

TABLE 1.8-6. Setting Duplex

Key entry Display

∗D 13:00
9A 09:0x

If x=0 the CR510 is set for full duplex.
If x=1 the CR510 is set for half duplex.

You may now change the option:

0A Set full duplex
1A Set half duplex

Where X is the powerup option currently
selected. You may now change the option:

0A Clears input locations, ports, flags, user

timer, and intermediate storage locations.

1A Clears intermediate storage only (leaves

Input Storage, Flags/Ports, and User Timer

as is).
2A Doesn’t clear anything.
3A Do not change power-up settings.

1-13

SECTION 1. FUNCTIONAL MODES

This is a blank page.

1-14

SECTION 2. INTERNAL DATA STORAGE

2.1 FINAL STORAGE AREAS, OUTPUT ARRAYS, AND MEMORY POINTERS

Final Storage is the memory where final
processed data are stored. Final Storage data
are transferred to your computer or external
storage peripheral.

The size of Final Storage is expressed in terms of
memory locations; one memory location is two
bytes. A low resolution data point (4 decimal
characters) occupies one memory location (2
bytes), whereas a high resolution data point (5
decimal characters) requires two memory
locations (4 bytes). Table 1.5-1 shows the default
allocation of memory locations to Program, Input,
Intermediate, and the two Final Storage areas.
The ∗A Mode is used to reallocate memory or
erase Final Storage (Section 1.5).

The default size of Final Storage with standard
memory is 62280 low resolution memory
locations.

Final Storage can be divided into two parts:
Final Storage Area 1 and Final Storage Area 2.

Final Storage Area 1 is the default storage area
and the only one used if the operator does not
specifically allocate memory to Area 2.

Two Final Storage Areas may be used to:

1. Output different data to different devices.

2. Separate archive data from real time display
data. In other words, you can record a short
time history of real time data and separately
record long term, archive data.

3. Record both high speed data (fast recording
interval) and slow data without having the
high speed data write over the slow data.

Each Final Storage Area can be represented as
ring memory (Figure 2.1-1) on which the newest
data are written over the oldest data.

The Data Storage Pointer (DSP) is used to
determine where to store each new data point in
the Final Storage area. The DSP advances to
the next available memory location after each
new data point is stored.

FIGURE 2.1-1. Ring Memory Representation of Final Data Storage

2-1

SECTION 2. I NTERNAL DATA STORAGE

Output Processing Instructions store data into
Final Storage only when the Output Flag is set.
The string of data stored each time the Output
Flag is set is called an OUTPUT ARRAY. The
first data point in the output array is a 3 digit
OUTPUT ARRAY ID. This ID number is set in
one of two ways:

1. In the default condition, the ID consists of
the program table number and the
Instruction Location Number of the
instruction which set the Output Flag for
that particular array of data. For example,
the ID of 118 in Figure 2.1-2 indicates that
the 18th instruction in Table 1 set the
Output Flag.

2. The output array ID can be set by the user
with the second parameter of Instruction 80
(Section 11). The ID can be set to any
positive integer up to 511. This option
allows the user to make the output array ID
independent of the programming. The
program can be changed (instructions
added or deleted) without changing the
output array ID. This avoids confusion
during data reduction, especially on long
term projects where program changes or
updates are likely.

Data are stored in Final Storage before being
transmitted to an external device. There are 4
pointers for each Final Storage Area which are
used to keep track of data transmission. These
pointers are:

1. Display Pointer (DPTR)

2. Printer Pointer (PPTR)

3. Telecommunications (Modem) Pointer (MPTR)

4. Storage Module Pointer (SPTR)
The DPTR is used to recall data to the keyboard/

display. The positioning of this pointer and data
recall are controlled from the keyboard (∗7 Mode).

The PPTR is used to control data transmission
to a printer or other serial device. Whenever
on-line printer transfer is activated (Instruction

96), data between the PPTR and DSP are
transmitted. The PPTR may also be positioned
via the keyboard for manually initiated data
transmission (∗8 Mode).

The MPTR is used in transmitting data over a
telecommunications interface. When
telecommunications is first entered, the MPTR is
set to the same location as the DSP. Positioning
of the MPTR is then controlled by commands from
the external calling device (Section 5.1).

FIGURE 2.1-2. Output Array ID

NOTE: If Instruction 80 is used to

designate the active Final Storage Area and
parameter 2 is 0, the output array ID is
determined by the position of Instruction 80
or by the position of the instruction setting
the Output Flag, whichever occurs last.

A start-of-array marker ($ in Figure 2.1-1) is
written into Final Storage with the Output Array
ID. This marker is used as a reference point
from which to number the data points of the
output array. The start of array marker occupies
the same Final Storage location as the Array ID
and is transparent for all user operations.

The SPTR is used to control data transmission to a
Storage Module. When on-line transfer is activated
by Instruction 96, data is transmitted each time an
output array is stored in Final Storage IF THE
STORAGE MODULE IS CONNECTED TO THE
CR510. If the Storage Module is not connected, the
CR510 does not transmit the data nor does it
advance the SPTR to the new DSP location. It
saves the data until the Storage Module is
connected. Then, during the next execution of
Instruction 96, the CR510 outputs all of the data
between the SPTR and the DSP and updates the
SPTR to the DSP location (Section 4.1)

The SPTR may also be positioned via the
keyboard for manually initiated data transfer to
the Storage Module (∗8 Mode, Section 4.2).

CAUTION: All memory pointers are set to
the DSP location when the datalogger
compiles a program. ALWAYS RETRIEVE
UNCOLLECTED DATA BEFORE MAKING
PROGRAM CHANGES.

2-2

SECTION 2. I NTERNAL DATA STORAGE

2.2 DATA OUTPUT FORMAT AND

RANGE LIMITS

Data are stored internally in Campbell Scientific's
Binary Final Storage Format (Appendix B.2).
Data may be sent to Final Storage in either LOW
RESOLUTION or HIGH RESOLUTION format.

2.2.1 RESOLUTION AND RANGE LIMITS

Low resolution data is a 2 byte format with 4
significant digits and a maximum magnitude of
+6999. High resolution data is a 4 byte format
with 5 significant digits and a maximum possible
output value of +99999 (see Table 2.2-1 below).

TABLE 2.2-1. Resolution Range Limits of

CR510 Data

Minimum Maximum

Resolution Zero

Low 0.000 +0.001 +6999.
High 0.0000 + .00001 +99999.

The resolution of the low resolution format is
reduced to 3 significant digits when the first (left
most) digit is 7 or greater. Thus, it may be
necessary to use high resolution output or an offset
to maintain the desired resolution of a measurement.
For example, if water level is to be measured and
output to the nearest 0.01 ft., the level must be less
than 70 ft. for low resolution output to display the

0.01 ft. increment. If the water level was expected
to range from 50 to 80 ft. the data could either be
output in high resolution or could be offset by 20 ft.
(transforming the range to 30 to 50 ft.).

Magnitude Magnitude

seventh digit. For example, the resolution of
97,386,924 is better than 10. The resolution of

0.0086731924 is better than 0.000000001.
A precise calculation of the resolution of a

number may be determined by representing the
number as a mantissa between .5 and 1
multiplied by 2 raised to some integer power. The
resolution is the product of that power of 2 and

-24

. For example, representing 478 as .9336 ∗

2

9

, the resolution is 29 ∗ 2

2
A description of Campbell Scientific's floating
point format may be found in the description of
the J and K Telecommunications Commands in
Appendix B.

-24

= 2

-15

= 0.0000305.

2.3 DISPLAYING STORED DATA ON
KEYBOARD/DISPLAY -

(Computer/terminal users refer to Section 5 for
instructions on entering the Remote Keyboard
State.)

Final Storage may be displayed by using the ∗7
Mode. Key ∗7.

If you have allocated memory to Final Storage
Area 2, the display will show:

07:00

Select which Storage Area you wish to view:

00 or 01 = Final Storage Area 1

02 = Final Storage Area 2

7 MODE

∗∗∗∗

The default for Final Storage is low resolution.
Program instruction 78 can be used to change this to
high resolution.

2.2.2 INPUT AND INTERMEDIATE STORAGE DATA FORMAT

While output data have the limits described
above, the computations performed in the
CR510 are done in floating point arithmetic. In
Input and Intermediate Storage, the numbers
are stored and processed in a binary format
with a 23 bit binary mantissa and a 6 bit binary
exponent. The largest and smallest numbers
that can be stored and processed are 9 x 10
and 1 x 10
number determines the resolution of the
arithmetic. A rough approximation of the
resolution is that it is better than 1 in the

-19

, respectively. The size of the

18

If no memory has been allocated to Final
Storage Area 2, this first window will be
skipped.

The next window displays the current DSP
location. Pressing A advances you to the
Output array ID of the oldest Array in the
Storage Area. To locate a specific Output
Array, enter a location number that positions the
Display Pointer (DPTR) behind the desired data
and press the "A" key. If the location number
entered is in the middle of an Output Array, the
DPTR is automatically advanced to the first data
point of the next Output Array. Repeated use of
the "A" key advances through the Output Array,
while use of the "B" key backs the DPTR
through memory.

The memory location of the data point is
displayed by pressing the "#" key. At this point,

2-3

SECTION 2. I NTERNAL DATA STORAGE

another memory location may be entered,
followed by the "A" key to jump to the start of
the Output Array equal to or just ahead of the
location entered. Whenever a location number
is displayed by using the "#" key, the
corresponding data point can be displayed by
pressing the "C" key.

The same element in the next Output Array with
the same ID can be displayed by hitting #A.
The same element in the previous array can be
displayed by hitting #B. If the element is 1
(Array ID), then #A advances to the next array
and #B backs up to the previous array. #0A
backs up to the start of the current array.

The keyboard commands used in the ∗7 Mode
are summarized in Table 2.3-1.

Advancing the DPTR past the Data Storage
Pointer (DSP) displays the oldest data point.
Upon entering the ∗7 Mode, the oldest Output
Array can be accessed by pressing the "A" key.

TABLE 2.3-1. ∗∗∗∗7 Mode Command Summary

Key Action

A
B
#

Advance to next data point
Back-up to previous data point
Display location number of currently

displayed data point value

C
# A

Display value of current location
Advance to same element in next

Output Array with same ID

# B

Back-up to same element in
previous Output Array with same ID

# 0 A

Back-up to the start of the current
Final Data Storage Array

∗

Exit ∗7 Mode

2-4

SECTION 3. INSTRUCTION SET BASICS

The instructions used to program the CR510 are divided into four types: Input/Output (I/O), Processing,
Output Processing, and Program Control. I/O Instructions are used to make measurements and store
the readings in input locations or to initiate analog or digital port output. Processing Instructions perform
mathematical operations using data from Input Storage locations and place the results back into
specified Input Storage locations. Output Processing Instructions provide a method for generating time
or event dependent data summaries from processed sensor readings residing in specified Input Storage
locations. Program Control Instructions are used to direct program execution based on time and or
conditional tests on input data and to direct output to external devices.

Instructions are identified by a number. There are a fixed number of parameters associated with each
instruction to give the CR510 the information required to execute the instruction. The set of instructions
available in the CR510 is determined by the CR510 Operating System.

3.1 PARAMETER DATA TYPES

There are 3 different data types used for
Instruction parameters: Floating Point (FP), 4
digit integers (4), and 2 digit integers (2). The
parameter data type is identified in the listings
of the instruction parameters in Sections 9-12.
Different data types are used to allow the
CR510 to make the most efficient use of its
memory.

Floating Point parameters are used to enter
numeric constants for calibrations or
mathematical operations. While it is only
possible to enter 5 digits (magnitude +.00001 to
+99999.), the internal format has a much
greater range (1x10

2.2.1). Instruction 30 can be used to enter a
number in scientific notation into an input
location.

-19

to 9x1018, Section

3.2 REPETITIONS

The repetitions parameter on many of the I/O,
Processing, and Output Processing Instructions
is used to repeat the instruction on a number of
sequential Input Channels or Input Storage
locations. For example, if you are making 2
differential voltage measurements on the same
voltage range, wire the inputs to sequential
channels and enter the Differential Voltage
Measurement Instruction once with 2 repetitions,
rather than entering 2 separate measurement
instructions. The instruction will make 2
measurements starting on the specified channel
number and continuing through the other
differential channel. The results will be stored in
the specified input location and the next
succeeding input location. Averages for both

measurements can be calculated by entering the
Average Instruction with 2 repetitions.

When several of the same type of
measurements will be made, but the
calibrations of the sensors are different, it
requires less time to make the measurements
using one measurement with repetitions and
then apply the calibrations with a scaling array
(Inst. 53) than it does to enter the instruction
several times in order to use a different
multiplier and offset. This is due to set up and
calibration time for each measurement
instruction. However, if time is not a constraint,
separate instructions may make the program
easier to follow.

3.3 ENTERING NEGATIVE NUMBERS

After keying in a number, press C or "-" to
change the number's sign. On floating point
numbers a minus sign (-) will appear to the left
of the number. Excitation voltages in millivolts
for I/O Instructions are 4 digit integers; when C
is keyed 2 minus signs (--) will appear to the
right of the number indicating a negative
excitation. Even though this display is the same
as that indicating an indexed input location,
(Section 3.4) there is no indexing effect on
excitation voltage.

3.4 INDEXING INPUT LOCATIONS

When used within a loop, the parameters for
input locations can be Indexed to the loop
counter. The loop counter is added to the
indexed value to determine the actual Input
Location the instruction acts on. Normally the
loop counter is incremented by 1 after each
pass through the loop. Instruction 90, Step

3-1

SECTION 3. INSTRUCTION SET BASICS

Loop Index, allows the increment step to be
changed. See Instructions 87 and 90, Section
12, for more details.

To index an input location (4 digit integer), C or
"-" is pressed after keying the value but before
entering the parameter. Two minus signs (--)
will be displayed to the right of the parameter.

3.5 VOLTAGE RANGE AND OVERRANGE DETECTION

The voltage RANGE code parameter on
Input/Output Instructions is used to specify the
full scale range of the measurement and the
integration period for the measurement (Table

3.5-1).
The full scale range selected should be the

smallest that will accommodate the full scale
output of the sensor being measured. Using
the smallest possible range will result in the
best resolution for the measurement.

Four different integration sequences are
possible. The relative immunity of the
integration sequences to random noise is: 60
Hz rej. = 50 Hz rej. > 2.72ms integ. > 272 µs
integ. The 60 Hz rejection integration rejects
noise from 60 Hz AC line power. The 50 Hz
rejection is for countries whose electric utilities
operate at 50 Hz (Section 13.1).

When a voltage input exceeds the range
programmed, the value which is stored is set to
the maximum negative number and displayed
as -99999 in high resolution or -6999 in low
resolution.

Voltages greater than 16 volts may permanently
damage the CR510.

NOTE: Voltages in excess of 5.5 volts
applied to a control port can cause the
CR510 to malfunction.

3.6 OUTPUT PROCESSING

Most Output Processing Instructions have both
an Intermediate Data Processing operation and
a Final Data Processing operation. For
example, when the Average Instruction, 71, is
initiated, the intermediate processing operation
increments a sample count and adds each new
Input Storage value to a cumulative total
residing in Intermediate Storage. When the
Output Flag is set, the final processing
operation divides the cumulative total by the
number of samples to find the average. The
average is then stored in final storage and the
cumulative total and number of samples are set
to zero in Intermediate Storage.

Final Storage Area 1 (Sections 1.5, 2.1) is the
default destination of data output by Output
Processing Instructions. Instruction 80 may be
used to direct output to either Final Storage
Area 2 or to Input Storage.

Output Processing Instructions requiring
intermediate processing sample the specified
input location(s) each time the Output
Instruction is executed, NOT each time the
location value is updated by an I/O Instruction.
For example: Suppose a temperature
measurement is initiated by Table 1 which has
an execution interval of 1 second.

An input voltage greater than +5 volts on one of
the analog inputs will result in errors and
possible overranging on the other analog inputs.

TABLE 3.5-1. Input Voltage Ranges and Codes

Range Code Full Scale Range Resolution*

Slow Fast

2.72ms 250 us 60 Hz 50 Hz
Integ. Integ. Reject. Reject.

1112131 ±2.5 mV 0.33 µV
2122232 ±7.5 mV 1.0 µV
3132333 ±25 mV 3.33 µV
4142434 ±250 mV 33.3 µV
5152535±2500 mV 333. µV

* Differential measurement, resolution for single-ended measurement is twice value shown.

3-2

SECTION 3. INSTRUCTION SET BASICS

The instructions to output the average
temperature every 10 minutes are in Table 2
which has an execution interval of 10 seconds.
The temperature will be measured 600 times in
the 10 minute period, but the average will be the
result of only 60 of those measurements
because the instruction to average is executed
only one tenth as often as the instruction to
make the measurement.

Intermediate Processing can be disabled by
setting Flag 9 which prevents Intermediate
Processing without actually skipping over the
Output Instruction.

All of the Output Processing Instructions store
processed data values when and only when the
Output Flag is set high (Section 3.7.1). The
Output Flag (Flag 0) is set high at desired
intervals or in response to certain conditions by
using an appropriate Program Control
Instruction (Section 12).

3.7 USE OF FLAGS: OUTPUT AND PROGRAM CONTROL

There are 10 flags which may be used in
CR510 programs. Two of the flags are
dedicated to specific functions: Flag 0 causes
Output Processing Instructions to write to Final
Storage, and Flag 9 disables intermediate
processing. Flags 1-8 may be used as desired
in programming the CR510. Flags 0 and 9 are
automatically set low at the beginning of each
execution of the program table. Flags 1-8 start
out low when a program is compiled with ∗0 and
remain unchanged until acted on by a Program
Control Instruction or until manually toggled
from the ∗6 Mode.

TABLE 3.7-1. Flag Description

Flag 0 - Output Flag
Flag 1 to 8 - User Flags
Flag 9 - Intermediate Processing

Disable Flag

Flags are set with Program Control Instructions.
The Output Flag (Flag 0) and the intermediate
programming disable flag (Flag 9) will always be
set low if the set high condition fails. The status
of flags 1-8 does not change when a conditional
test is false.

3.7.1 THE OUTPUT FLAG

A group of processed data values is placed in
Final Data Storage by Output Processing
Instructions when the Output Flag (Flag 0) is set
high. This group of data is called an Output
Array. The Output Flag is set using Program
Control Instructions according to time or event
dependent intervals specified by the user. The
Output Flag is set low at the beginning of each
execution of the program table.

Output is most often desired at fixed intervals;
this is accomplished with Instruction 92, If Time.
Output is usually desired on the even interval,
so Parameter 1, time into the interval, is 0. The
time interval (Parameter 2), in minutes, is how
often output will occur; i.e., the Output Interval.
The command code (Parameter 3) is 10,
causing Flag 0 to be set high. The time interval
is synchronized to 24 hour time; output will
occur on each integer multiple of the Output
Interval starting from midnight (0 minutes). If
the Output Interval is not an even divisor of
1440 minutes (24 hours), the last output interval
of the day will be less than the specified time
interval. Output will occur at midnight and will
resume synchronized to the new day.
Instruction 92 is followed in the program table
by the Output Instructions which define the
Output Array desired.

Each group of Output Processing Instructions
creating an Output Array is preceded by a
Program Control Instruction that sets the Output
Flag high.

NOTE: If the Output Flag is already set high
and the test condition of a subsequent
Program Control Instruction acting on Flag
0 fails, the flag is set low. This eliminates
entering another instruction to specifically
reset the Output Flag before proceeding to
another group of Output Instructions with a
different output interval.

3.7.2 THE INTERMEDIATE PROCESSING DISABLE FLAG

The Intermediate Processing Disable Flag (Flag

9) suspends intermediate processing when it is
set high. This flag is used to restrict sampling
for averages, totals, maxima, minima, etc., to
times when certain criteria are met. The flag is
automatically set low at the beginning of each
execution of the program table.

3-3

SECTION 3. INSTRUCTION SET BASICS

TABLE 3.7-2. Example of the Use of Flag 9

1: If time is (P92)

1: 0 Minutes (Seconds --) into a
2: 10 Interval (same units as above)
3: 10 Set Ouptut Flag High (Flag 0)

2: If (X!F) (P89)

1: 14 X Loc [ Wind_spd ]
2: 4 <
3: 4.5 F

4: 19 Set Intermed. Proc. Disable Flag High (Flag 9)
3: Histogram (P75) ; See Section 11 for details of this intruction.
4: Do (P86) ; Required when additional output processing follows

1: 29 Set Intermed. Proc. Disable Flag Low (Flag 9)
5: Maximum (P73)

1: 1 Reps

2: 00 Time Option

3: 14 Loc [ Wind_spd ]

As an example, suppose it is desired to obtain a
wind speed rose incorporating only wind speeds
greater than or equal to 4.5 m/s. The wind
speed rose is computed using the Histogram
Instruction 75, and wind speed is stored in input
location 14, in m/s. Instruction 89 is placed just
before Instruction 75 and is used to set Flag 9
high if the wind speed is less than 4.5 m/s:

NOTE: Flag 9 is automatically reset the
same as Flag 0. If the intermediate
processing disable flag is already set high
and the test condition of a subsequent
Program Control Instruction acting on Flag
9 fails, the flag is set low. This feature
eliminates having to enter another
instruction to specifically reset Flag 9 low
before proceeding to another group of test
conditions.

3.7.3 USER FLAGS

Flags 1-8 are not dedicated to a specific
purpose and are available to the user for
general programming needs. The user flags
can be manually toggled from the keyboard in
the ∗6 Mode (Section 1.3). By inserting the flag
test (Instruction 91) at appropriate points in the
program, the user can use the ∗6 Mode to
manually direct program execution.

3.8 PROGRAM CONTROL LOGICAL CONSTRUCTIONS

Most of the Program Control Instructions have a
command code parameter which is used to
specify the action to be taken if the condition
tested in the instruction is true. Table 3.8-1 lists
these codes.

TABLE 3.8-1. Command Codes

0 Go to end of program table
1-9, 79-99 Call Subroutine 1-9, 79-99
10-19 Set Flag 0-9 high
20-29 Set Flag 0-9 low
30 Then Do
31 Exit loop if true
32 Exit loop if false
41 Set Port 1 high
51 Set Port 1 low
61 Toggle Port 1
71 Pulse Port 1

1

98 is a special subroutine which can be
called by Control port 2 going high; see
Instruction 85 for details (Section 12).

2

If this command is executed while in a
subroutine, execution jumps directly to the
end of the table that called the subroutine.

1

2

3-4

3.8.1 IF THEN/ELSE COMPARISONS

Program Control Instructions can be used for If
then/else comparisons. When Command 30
(Then do) is used with Instructions 83 or 88-92,
the If Instruction is followed immediately by
instructions to execute if the comparison is true.
The Else Instruction (94) is optional and is
followed by the instructions to execute if the
comparison is false. The End Instruction (95)
ends the If then/else comparison and marks the
beginning of the instructions that are executed
regardless of the outcome of the comparison
(see Figure 3.8-1).

SECTION 3. INSTRUCTION SET BASICS

FIGURE 3.8-2. Logical AND Construction

;Logical AND construction example:
;Check first condition

6: If (X!F) (P89)

1: 1 X Loc [ DO_ppm ]
2: 4 <
3: 3.5 F
4: 30 Then Do

FIGURE 3.8-1. If Then/Else

Execution Sequence

;Logical ELSE construction example:
;Check condition

1: If (X!F) (P89)

1: 1 X Loc [ DO_ppm ]
2: 4 <
3: 3.5 F
4 30 Then Do

;Instruction(s) to execute if above condition is true
2: Do (P86)

1: 41 Set Port 1 High
3: Else (P94)
;Instruction(s) to execute if above condition is false

4: Do (P86)

1: 51 Set Port 1 Low

;AND check second condition
7: If (X!F) (P89)

1: 2 X Loc [ Counter ]
2: 3 >=
3: 10 F
4: 30 Then Do

;Instruction(s) to execute if both conditions are true
8: Do (P86)

1: 41 Set Port 1 High
9: End (P95)
10: End (P95)
If Then/Else comparisons may be nested to

form logical AND or OR branching. Figure 3.8­2 illustrates an AND construction. If conditions A
and B are true, the instructions included
between IF B and the first End Instruction will
be executed.

If either of the conditions is false, execution will
jump to the corresponding End Instruction,
skipping the instructions between.

5: End (P95)

A logical OR construction is also possible.
Figure 3.8-3 illustrates the instruction sequence
that will result in subroutine X being executed if
either A or B is true.

3-5

SECTION 3. INSTRUCTION SET BASICS

;Logical OR construction example:
11: If (X!F) (P89)

1: 1 X Loc [ DO_ppm ]
2: 4 <
3: 3.5 F
4: 30 Then Do

12: Do (P86)

1: 41 Set Port 1 High
13: Else (P94)
14: If (X!F) (P89)

1: 2 X Loc [ counter ]

2: 3 >=

3: 10 F

4: 30 Then Do
15: Do (P86)

1: 41 Set Port 1 High
16: End (P95)
17: End (P95)
A logical OR can also be constructed by setting

a flag high if a comparison is true. (The flag is
cleared or set low before making comparisons.)
After all comparisons have been made, execute
the desired instructions if the flag is set high.

;CASE Logic construction example:
18: CASE (P93)

1: 3 Case Loc [ Reading ]

19: If Case Location < F (P83)

1: 1.8 F
2: 30 Then Do

;See Section 9 for details of this Instruction
20: AC Half Bridge (P5)

21: End (P95)
22: If Case Location < F (P83)

1: 9.25 F
2: 30 Then do

;See Section 9 for details of this Instruction
23: Full Bridge (P6)

24: End (P95)
25: If Case Location < F (P83)

1: 280 F
2: 30 Then do

;See Section 9 for details of this Instruction
26: Full Bridge (P6)

27: End (P95)

The Begin Case Instruction 93 and If Case
Instruction 83 allow a series of tests on the
value in an input location. The case test is
started with Instruction 93 which specifies the
location to test. A series of Instruction 83s are
then used to compare the value in the location
with fixed values. When the value in the input
location is less than the fixed value specified in
Instruction 83, the command in that Instruction
83 is executed, and execution branches to the
END Instruction 95 which closes the case test
(see Instruction 93, Section 12).

28: End (P95)

3.8.2 NESTING

A branching or loop instruction which occurs
before a previous branch or loop has been
closed is nested. The maximum nesting level is
11 deep. Loop Instruction 87 and Begin Case
Instruction 93 both count as 1 level.
Instructions 83, 86, 88, 89, 91, and 92 each
count as one level when used with the
Command "30" which is the "Then Do"
command. Use of Else, Instruction 94, also
counts as one nesting level each time it is used.
For example, the AND construction above is
nested 2 deep while the OR construction is
nested 3 deep.

Subroutine calls do not count as nesting with
the above instructions, though they have their
own nesting limit (maximum of 6, see
Instruction 85, Section 12). Branching and loop
nesting start at zero in each subroutine.

3-6

Any number of groups of nested instructions
may be used in any of the three Programming
Tables. The number of groups is only restricted
by the program memory available.

3.9 INSTRUCTION MEMORY AND EXECUTION TIME

Each instruction requires program memory and
uses varying numbers of Input, Intermediate,
and Final Storage locations. Tables 3.9-1 to

3.9-4 list the memory used by each instruction
and the approximate time required to execute it.

When attempting to make a series of
measurements and calculations at a fast rate, it
is important to examine the time required for the
automatic calibration sequence and possibly
make use of the program controlled calibration,
Instruction 24. Section 13.7 describes the
calibration process.

NOTE: EDLOG generates a “trace” file with
the extension .PTI which shows the
estimated program execution time.

SECTION 3. INSTRUCTION SET BASICS

3-7

SECTION 3. INSTRUCTION SET BASICS

3-8

SECTION 3. INSTRUCTION SET BASICS

TABLE 3.9-2. Processing Instruction Memory and Execution Times R = No. of Reps.

INPUT MEMORY PROG.

INSTRUCTION LOC.

INTER. LOC. BYTES EXECUTION TIME (ms)

30 Z=F 1 0 9 1.0 + 0.2 ∗ exponent
31 Z=X 1 0 6 0.7
32 Z=Z+1 1 0 4 0.8
33 Z=X+Y 1 0 8 1.2
34 Z=X+F 1 0 10 1.1
35 Z=X-Y 1 0 8 1.2
36 Z=X∗Y1081.5
37 Z=X∗F10101.2
38 Z=X/Y 1 0 8 3.0
39 Z=SQRT(X) 1 0 6 9.0
40 Z=LN(X) 1 0 6 8.4
41 Z=EXP(X) 1 0 6 6.6
42 Z=1/X 1 0 6 2.9
43 Z=ABS(X) 1 0 6 1.0
44 Z=FRAC(X) 1 0 6 1.1
45 Z=INT(X) 1 0 6 1.4
46 Z=X MOD F 1 0 10 3.5
47 Z=X

Y

1 0 8 14.9
48 Z=SIN(X) 1 0 6 7.3
49 SPA. MAX 1 or 2 0 8 2.7 + 0.6 * swath
50 SPA. MIN 1 or 2 0 8 2.3 + 0.6 * swath
51 SPA. AVG 1 0 8 3.0 + 0.6 * swath
52 RUNNING AVG 1 (R ∗ par 4) + R + 1 11 2.1 + 3.7R
53 A∗X+B 4 0 36 3.5
54 BLOCK MOVE R 0 10 0.3 + 0.2R
55 POLYNOMIAL R 0 31 1.2 + (2.0 + 0.4 ∗ order)R
56 SAT. VP 1 0 6 4.5
58 LP FILTER R R + 1 13 1.0 + 2.2R
59 X/(1-X) 1 0 9 0.4 + 1.2R
61 INDIR. MOVE 1 0 6 0.6
63 PARA.EXTN. 0 0 10 0.2
65 BULK LOAD 8 0 36 4.5
66 ARC TAN 1 0 8 8.7
68 4 DIG PARA. EXTN. 0 0 8 0.7

3-9

SECTION 3. INSTRUCTION SET BASICS

TABLE 3.9-3. Output Instruction Memory and Execution Times R = No. of Reps.

INTER. MEM. FINAL PROG. EXECUTION TIME (ms)

INSTRUCTION LOC.

VALUES

1

BYTES FLAG 0 LOW FLAG 0 HIGH

69 WIND VECTOR 2+9R (2, 3, or 4)R 12

Options 00, 01, 02 4.0 + 17.4R 3.3 + 70.7R
Options 10, 11, 12 3.0 + 16.3R 4.0 + 75R

70 SAMPLE 0 R 6 0.2 0.5+ 0.4R
71 AVERAGE 1+R R 7 0.6+ 1.1R 1.5+ 4.4R
72 TOTALIZE R R 7 0.6+ 1.0R 1.0+ 1.7R
73 MAXIMIZE (1 or 2)R (1,2, or 3)R 8 1.0+ 1.2R 5.0+ 3.0R
74 MINIMIZE (1 or 2)R (1,2, or 3)R 8 0.8+ 1.2R 5.0+ 3.0R
75 HISTOGRAM 1+bins∗Rbins∗R 24 0.8+ 3.4R 1.6+ 5.2 + (1.4 ∗ bins)R
77 REAL TIME 0 1 to 4 4 0.2 3.8
78 RESOLUTION 0 0 3 0.4 0.4
79 SMPL ON MM R R 7 0.4 1.7 + 1.1R

1

80 STORE AREA

00 70.3 0.3

82 STD. DEV. 1+3R R 7 1.5+ 2.0R 2.9+ 2.1R

1

Output values may be sent to either Final Storage area or Input Storage with Instruction 80.

TABLE 3.9-4. Program Control Instruction Memory and Execution Times

MEMORY

INTER. PROG.

INSTRUCTION LOC. BYTES EXECUTION TIME (ms)

83 IF CASE <F 0 10 0.5
85 LABEL SUBR. 0 3 0
86 DO 0 6 0.3
87 LOOP 1 10 0.3
88 IF X<=>Y 0 11 0.8
89 IF X<=>F 0 13 0.6
90 LOOP INDEX 0 3 0.7
91 IF FLAG/PORT 0 7 0.4
92 IF TIME 1 12 0.4
93 BEGIN CASE 1 8 0.3
94 ELSE 0 4 0.2
95 END 0 4 0.2
96 SERIAL OUT 0 3 Option: 0x 1x 2x 3x

Time: 0.4 1.8 2.1 0.9
Option: 4x 5x 6x 7x

Time: 1.7 1.9 0.7 0.5
97 INIT.TELE. 7 17 2.3
120 GOES SAT 0 or 2 5 8000
121 ARGOS SAT 0 8 250

3-10

SECTION 3. INSTRUCTION SET BASICS

3.10 ERROR CODES

There are four types of errors flagged by the
CR510: Compile, Run Time, Editor, and ∗D Mode.
Compile errors are errors in programming which
are detected once the program is entered and
compiled for the first time (∗0, ∗6, or ∗B Mode
entered). If a programming error is detected during
compilation, an E is displayed with the 2 digit error
code. The Instruction Location Number of the
Instruction which caused the error is displayed to
the right of the error code (e.g., E23 105; 105
indicates that the fifth instruction in Table 1 caused
error 23). Error 22, missing END, will indicate the
location of the instruction which the compiler
cannot match with an END instruction.

Run time errors are detected while the program
is running. The number of the instruction being
executed at the time the error is detected is
displayed to the right of the error code (e.g.,
E09 06 indicates that an Instruction 6 in the
program is attempting to store data in input
locations beyond those allocated). Run time
errors 9 and 31 are the result of programming
errors. While E08 will display the number of the
instruction that was being executed when the
error occurred, it is unlikely that the instruction
has anything to do with the error.

transients. Frequent repetitions of E08 are
indicative of a hardware problem or a software
bug and should be reported to Campbell
Scientific. The CR510 keeps track of the
number of times (up to 99) that E08 has
occurred. The number can be displayed and
reset in the ∗B Mode (Section 1.6) or with the
Telecommunications A command (Section 5.1).

Error 10 is displayed if the primary power drops
below 9.6 volts. When this happens, the
CR510 stops executing programs. The low
voltage counter (∗B Window 9, Section 1.6)
counts the number of times the voltage drops
below 9.6 volts and displays a double dash (--) if
the CR510 is currently in a low voltage shut
down. Below approximately 8.5 volts the
CR510 will not communicate with the CR10KD
or modem, although there may be enough
power to display characters on the CR10KD.

Editor errors are detected as soon as an
incorrect value is entered and are displayed
immediately. Only the error code is displayed.
∗D Mode errors indicate problems with saving
or loading a program. Only the error code is
displayed.

TABLE 3.10-1. Error Codes

If there is a run time error in a table with a fast
execution interval, the error may be written to
the display so frequently that it seems the
CR510 is not responding to the keyboard.
Once the program is stopped, normal function
will return. To stop the program some entry
must be changed which requires recompiling
(Section 1.1.4). For example, enter 0 for the
execution interval of Table 1 (i.e., enter ∗1A0A
as fast as possible). The program can easily be
stopped by pressing any key while the CR10KD
is displaying “HELLO” after applying power (turn
the CR510 off and then on again). This delays
program execution for about two minutes,
allowing the program to be changed.

Error 8 is the result of a hardware and software
"watchdog" that checks the processor state,
software timers, and program related counters.
The watchdog will attempt to reset the
processor and program execution if it finds that
the processor has bombed or is neglecting
standard system updates, or if the counters are
out of allowable limits. Error code 08 is flagged
when the watchdog performs this reset. E08 is
occasionally caused by voltage surges or

Code Type Description

03 Editor Program table full
04 Compile Intermediate Storage full
05 Compile Storage Area #2 not

allocated

08 Run Time CR510 reset by

watchdog timer
09 Run Time Insufficient Input Storage
10 Run Time Low battery voltage
11 Editor Attempt to allocate more

Input or Intermediate

Storage than is available
12 Compile Duplicate ∗4 ID
20 Compile SUBROUTINE encountered

before END of previous

subroutine
21 Compile END without IF, LOOP or

SUBROUTINE
22 Compile Missing END
23 Compile Nonexistent

SUBROUTINE
24 Compile ELSE in SUBROUTINE

without IF
25 Compile ELSE without IF

3-11

SECTION 3. INSTRUCTION SET BASICS

26 Compile EXIT LOOP without

LOOP

27 Compile IF CASE without BEGIN

CASE

30 Compile IF and/or LOOP nested

too deep

31 Run Time SUBROUTINES nested

too deep

32 Compile Instruction 3 and interrupt

subroutine use same port
40 Editor Instruction does not exist
41 Editor Incorrect execution

interval
60 Compile Insufficient Input Storage
92 Compile Instruction 92, intervals in

seconds: Time into Interval

> 59 or Interval > 60
94 ∗D MODE Program Storage Area

full
95 ∗D MODE Program does not exist in

Flash memory
96 ∗D MODE Addressed device not

connected or wrong

address (see Table 1.8-2)
97 ∗D MODE Data not received within

30 seconds
98 ∗D MODE Uncorrectable errors

detected
99 ∗D MODE Wrong file type or editor

error

3-12

SECTION 4. EXTERNAL STORAGE PERIPHERALS

External data storage devices are used to provide a data transfer medium that the user can
carry from the test site to the lab and to supplement the internal storage capacity of the CR510,
allowing longer periods between visits to the site. The standard data storage peripheral for the
CR510 is the Storage Module (Section 4.4). Output to a printer or related device is also
possible (Section 4.3).

Data output to a peripheral device can take place ON-LINE (automatically, as part of the
CR510's routine operation) or it can be MANUALLY INITIATED. On-line data transfer is

∗

accomplished with Instruction 96 (Section 4.1). Manual initiation is done in the
(Section 4.2).

The CR510 can output data to multiple peripherals. The CR510 activates the peripheral it
sends data to in one of two ways (Section 6.2):

1. A specific pin in the 9-pin connector is dedicated to that peripheral; when that pin goes
high, the peripheral is enabled. This is referred to as "PIN-ENABLED" or simply
"ENABLED".

2. The peripheral is synchronously addressed by the CR510. This is referred to as
"ADDRESSED".

Modems are pin-enabled. Only one modem device may be connected to the CR510 at any one
time. The CR510 considers the following devices to be pin-enabled modems: SC32A, SC932,
short-haul, MD9, radio modems, and telephone modems except for voice modems.

8 Mode

The SM192, SM716, and CSM1 Storage Modules are addressed. The CR510 can tell when the
addressed device is present. The CR510 will not send data meant for the Storage module if the
Storage Module is not present (Section 4.4.2). Other addressed devices include the CR10KD and
voice modems.

∗

9 Mode (Section 4.5) allows the user to communicate directly with the Storage Module and

The
to perform several functions, including review of data, battery test, review of Storage Module
status, etc.

Cassette tape data storage is not supported by the CR510.

4.1 ON-LINE DATA TRANSFER ­INSTRUCTION 96

All on-line data output to a peripheral device is
accomplished with Instruction 96. (Instruction
96 can also be used to transfer data from one
Final Storage Area to the other, Section 8.8,

12). This instruction must be included in the
datalogger program for on-line data transfer to
take place. Instruction 96 should follow the
Output Processing Instructions, but only needs
to be included once in the program table unless
both Final Storage areas are in use. The
suggested programming sequence is:

1. Set the Output Flag.

2. If both Final Storage Areas are in use or if
you wish to set the Output Array ID, enter
Instruction 80 (Section 11).

3. Enter the appropriate Output Processing
Instructions.

4. Enter Instruction 96 to enable the on-line
transfer of Final Storage data to the
specified device. If outputting to more than
one device, Instruction 96 must be entered
separately for each device.

5. Repeat steps 2 through 4 if you wish to
output data to the other Final Storage Area
and the peripheral.

4-1

SECTION 4. EXTERNAL STORAGE PERIPHERALS

Instruction 96 has a single parameter which
specifies the peripheral to send output to. Table

4.1-1 lists the output device codes.

TABLE 4.1-1. Output Device Codes for

Instruction 96 and ∗∗∗∗8 Mode

Code Device

ADDRESSED PRINTER
1y Printable ASCII
2y Comma separated ASCII
3y Binary

PIN ENABLED PRINTER
4y Printable ASCII
5y Comma separated ASCII
6y Binary

y = BAUD RATE CODES

0 300
1 1200
2 9600
3 76,800

7N Storage Module N (N=address, 1...8)
7N-- Output File Mark to Storage Module N
80 To the other Final Storage Area [Inst.

96 only], new data since last output
81 To the other Final Storage Area

[Inst. 96 only], entire active Final

Storage Area
The source of data for Instruction 96 is the

currently active Final Storage Area as set by
Instruction 80 (the default is Final Storage Area 1
at the beginning of each program table execution).

If the CR510 is using the 9-pin connector for
other I/O tasks when Instruction 96 is executed,
the output request is put in a queue and
program execution continues. As the 9-pin

connector becomes available, each device in
the queue gets its turn.

An output request is not put in the queue if the
same device is already in the queue. The data
contained in the queue (and which determine a
unique entry) are the device, baud rate (if
applicable), and the Final Storage Area.

When an entry reaches the top of the queue, the
CR510 sends all data accumulated since the last
transfer to the device up to the location of the
DSP at the time the device became active.

Printer output can be either pin-enabled or
addressed. However, there is not a pin
specifically dedicated to print enable. When a
pin-enabled print output is specified, the SDE
line, which is normally used in the addressing
sequence, is used as a print enable. This
allows some compatibility with the CR21, 21X,
and CR7 dataloggers which have a Print Enable
line. The pin-enabled print option will result in
garbage being sent to the print peripheral if an
addressed device is also connected to the
CR510 (i.e., CR10KD, SM192 or SM716 etc.).
The SDC99 Synchronous Device Interface can
convert a print device to an Addressed
peripheral (Section 6.2).

The STORAGE MODULE address is important
only when using more than one Storage
Module. One is a universal address which will
find the Storage Module with lowest number
address that is connected. If a Storage Module
is not connected, the CR510 will not advance
the SPTR (Section 2.1) and the Storage Module
drops out of the queue until the next time
Instruction 96 is executed. Section 4.4 contains
specifics on the Storage Modules.

Display

Key ID:DATA

8

∗

A
A

A

A

08:00 Key 1 or 2 for Storage Area. (This window is skipped if no memory has

01:XX Key in Output Device Option. See Table 4.1-1.
02:XXXXX Start of dump location. Ini tially the SPTR or PPTR location; a different

03:XXXXX End of dump location. Initially the DSP location; a different location may

04:00 Ready to dump. To initiate dump, key any number, then A. While

4-2

TABLE 4.2-1. ∗∗∗∗8 Mode Entries

Description

been allocated to Final Storage Area 2.)

location may be entered if desired.

be keyed in if desired.

dumping, "04" will be displayed in the ID field and the location number
in the Data field. The location number will stop incrementing when the
dump is complete. (Any key aborts transmission after completion of the
current data block.)

SECTION 4. EXTERNAL STORAGE PERIPHERALS

4.2 MANUALLY INITIATED DATA
OUTPUT -

Data transfer to a peripheral device can be
manually initiated in the ∗8 Mode. This process
requires that the user have access to the
CR510 through a terminal or the CR10KD. The
∗8 Mode allows the user to retrieve a specific
block of data, on demand, regardless of
whether or not the CR510 is programmed for
on-line data output.

If external storage peripherals are not left on­line, the maximum time between collecting data
must be calculated to ensure that data in Final
Storage are not lost due to write-over. To
calculate this time it is necessary to know: (1)
the size of Final Storage, (2) the number of
Output Arrays being generated, (3) the number
of low and/or high resolution data points per
Output Array, and (4) the rate at which Output
Arrays are placed into Final Storage. When
calculating the number of data points per
Output Array, remember to add 1 data point per
array for the Output Array ID.

For example, assume that 62,280 locations are
assigned to Final Storage (∗A Mode), and that 1
Output Array, containing the Array ID (1 memory
location), 9 low resolution data points (9 memory
locations) and 5 high resolution data points (10
memory locations), is stored each hour. In
addition, an Output Array with the Array ID and 5
high resolution data points (11 memory locations)
is stored daily. This is a total of 491 memory
locations per day ((20 x 24) + 11). 62,280 divided
by 491 = 126.8 days. Therefore, the CR510
would have to be visited every 126 days to
retrieve data, because write-over would begin on
the 127th day. The site should be visited more
frequently than this for routine maintenance.
Thus data storage capacity would not be a factor
in determining how frequently to visit the site.

8 MODE

∗∗∗∗

The output device codes used with the ∗8 Mode
are the same as those used with Instruction 96
(Table 4.1-1), with the exception of the option to
transfer data from one Final Storage area to the
other (80, 81). Table 4.2-1 lists the keystrokes
required to initiate a ∗8 data dump.

4.3 PRINTER OUTPUT FORMATS

Printer output can be sent in binary Final Storage
Format (Appendix C.2), Printable ASCII, or
Comma Separated ASCII. These ASCII formats
may also be used when data from the Storage
Modules or Telecommunications are stored on
disk with Campbell Scientific's datalogger support
software.

4.3.1 PRINTABLE ASCII FORMAT

In the Printable ASCII format each data point is
preceded by a 2 digit data point ID and a (+) or
(−) sign. The ID and fixed spacing of the data
points make particular points easy to find on a
printed output. This format requires 10 bytes
per data point to store on disk.

Figure 4.3-1 shows both high and low resolution
data points in a 12 data point Output Array. The
example data contains Day, Hour-Minute, and
Seconds in the 2nd - 4th data points. REMEMBER!
You must specifically program the CR510 to output
the date and time values. The Output Array ID,
Day, and Time are always 4 character numbers,
even when high resolution output is specified. The
seconds resolution is .125 seconds.

Each full line of data contains 8 data points (79
characters including spaces), plus a carriage
return (CR) and line feed (LF). If the last data
point in a full line is high resolution, it is followed
immediately with a CR and LF. If it is low
resolution, the line is terminated with a space,
CR and LF. Lines of data containing less than 8
data points are terminated similarly after the last
data point.

4-3

SECTION 4. EXTERNAL STORAGE PERIPHERALS

FIGURE 4.3-1. Example of CR510 Printable ASCII Output Format

4.3.2 COMMA SEPARATED ASCII

Comma Separated ASCII strips all IDs, leading
zeros, unnecessary decimal points and trailing
zeros, and plus signs. Data points are separated
by commas. Arrays are separated by Carriage
Return Line Feed. Comma Separated ASCII
requires approximately 6 bytes per data point.
Example:

1,234,1145,23.65,-12.26,625.9
1,234,1200,24.1,-10.98,650.3

4.4 STORAGE MODULE

The Storage Module stores data in battery
backed RAM. Backup is provided by an internal
lithium battery. The RAM is internal on the
SM192/716 and on a PCMCIA card in the CSM1.
Operating power is supplied by the CR510 over
pin 1 of the 9-pin connector. Whenever power is
applied to the 9-pin connector (after having been
off), the Storage Module places a File Mark in
the data (if a File Mark is not the last data point
already in storage).

The File Mark separates data. For example, if
you retrieve data from one CR510, disconnect
the Storage Module and connect it to a second
CR510, a File Mark is automatically placed in
the data. This mark follows the data from the
first CR510 but precedes the data from the
second.

The SM192 has 192K bytes of RAM storage; the
SM716 has 716K bytes. Both can be configured
as either ring or fill and stop memory. The size of
memory in the CSM1 depends on the PC Card
used. The CSM1 is always fill and stop.

4.4.1 STORAGE MODULE ADDRESSING

The CSM1 does not support individual addresses.
Use address 1 when sending data to the CSM1.

The SM192/716 Storage Modules can have
individual addresses. Different addresses allow 1)
up to 8 Storage Modules to be connected to the
CR510 during on-line output, 2) different data to be
output to different Modules, and 3) transfer of data
from a Module that is left with the CR510 to a
Module that is hand carried to the site for data
transfer (∗9 Mode).

Storage Modules are assigned addresses (1-8) either
through the ∗9 Mode or with the SMCOM or SMS
software. 1 is the default address when the Storage
Module is reset. Unless you are using one of the
features which require different addresses, you need
not assign any other address.

Address 1 is also a universal address when
sending data or commands to a storage module
with Instruction 96, ∗8, or ∗9. When address 1
is entered in the ∗9 Mode (default) or in the
device code (71, Table 4.2-1) for Instruction 96
or the ∗8 Mode, The CR510 searches for the

4-4

SECTION 4. EXTERNAL STORAGE PERIPHERALS

Storage Module with the lowest address that is
not full (fill and stop configuration only) and
addresses it. In other words, if a single Storage
Module is connected, and it is not full, address 1
will address that Storage Module regardless of
the address that is assigned to the Module.

Address 1 would be used with Instruction 96 if
several Storage Modules with different
addresses were connected to the CR510 and
were to be filled sequentially. The Storage
modules would be configured as fill and stop.
When the lowest addressed Module was full
data would be written to the next lowest
addressed Module, etc.

4.4.2 STORAGE MODULE USE WITH INSTRUCTION 96

When output to the Storage Module is enabled
with Instruction 96, the Storage Module(s) may
be either left with the CR510 for on-line data
transfer and periodically exchanged, or brought
to the site for data transfer.

USE OF STORAGE MODULE TO PICK UP
DATA

The CR510 is capable of recognizing whether or
not the Storage Module is connected. Each time
Instruction 96 is executed and there is data to
output, the CR510 checks for the presence of a
Storage Module. If one is not present, the
CR510 does not attempt to output data. Instead,
the CR510 saves the data and continues its
other operations without advancing the Storage
Module Pointer (SPTR, Section 2.1).

When the user finally does connect the Storage
Module to the CR510, two things happen:

1. Immediately upon connection, a File Mark is

placed in the Storage Module Memory
following the last data stored (if a File Mark
wasn't the last data point already in storage).

2. During the next execution of Instruction 96,

the CR510 recognizes that the Storage
Module (SM) is present and outputs all data
between the SPTR and the DSP location.

The File Mark allows the operator to distinguish
blocks of data from different dataloggers or
from different visits to the field.

To be certain that the Storage Module has been
connected to the CR510 during an execution of
P96, the user can:

• Leave the Storage Module connected for a time

period longer than an execution interval or

• Use the SC90 9-Pin Serial Line Monitor. The
SC90 contains an LED which lights up during
data transmission. The user connects the SM
to the CR510 with the SC90 on the line and
waits for the LED to light. When the light goes
off, data transfer is complete and the SM can
be disconnected from the CR510.

4.4.3 ∗∗∗∗8 DUMP TO STORAGE MODULE

In addition to the on-line data output procedures
described above, output to the Storage Module
can be manually initiated in the ∗8 Mode. The
procedure for setting up and transferring data is
as follows:

1. Connect both the CR10KD Keyboard/Display
(or terminal) and the Storage Module to the
CR510 using the SC12 cable. (For terminals,
an SC32A is needed. See Section 5 for
interfacing details.)

2. Key in the appropriate commands as listed
in Table 4.2-1.

4.5

9 MODE -- SM192/716 STORAGE

∗∗∗∗

MODULE COMMANDS

The CSM1 does not support the ∗9 Mode Commands.
The ∗9 Mode is used to issue commands to the

SM192/716 Storage Module, through the CR510,
using the CR10KD or a terminal/computer. These
commands are like ∗ Modes for the Storage
Module and in some cases are directly analogous
to the CR510 ∗ Modes. Command 7 enters a
mode used to review stored data, and 8 is used to
transfer data between two Storage Modules
connected to the CR510. The operations with the
Storage Module are not directly analogous as may
be seen in Table 4.5-1 which lists the commands
(e.g., when reviewing data, #A advances to the
start of the next Output Array rather than to the
same element in the next array with the same ID).

When ∗9 is keyed, the CR510 responds: 09:01.
1 is the default address for the Storage Module
(Section 4.4.1). If you have more than 1 Storage
Module connected, enter the address of the
desired Storage Module. Address 1 will always
work if only one Module is connected. Key A and
the CR510 responds: 9N:00 Where N is the
address which was entered.

You may now enter any of the commands in
Table 4.5-1 (key in the command number and
enter with A). Most commands have at least one
response. Advance through the responses and
return to the *9 command state by keying A.

4-5

SECTION 4. EXTERNAL STORAGE PERIPHERALS

TABLE 4.5-1. ∗∗∗∗9 Commands for Storage Module

COMMAND DISPLAY DESCRIPTION

1 01: 0000 RESET, enter 248 to erase all data and programs. While erasing,

the SM checks memory. The number of good chips is then

01: XX displayed (6 for SM192, 22 SM716).

3 03: 01 INSERT FILE MARK, 1 indicates that the mark was inserted, 0

that it was not.

4 04: XX DISPLAY/SET MEMORY CONFIGURATION enter the

appropriate code to change configuration 0=ring, 1=fill & stop

5 DISPLAY STATUS (A to advance to each window)

01: ABCD Window 1:

AB Storage pointer location (chip no.)

CD Total good RAM chips (1-22)

02: ABCD Window 2:

AB Display pointer location (chip no.)

C Unloaded Batt. Chk. 0=low, 1=OK

D No. of Programs stored (Max=8)

03: A0CD Window 3:

A Errors logged (up to 9)

0 Not Used

C Memory Config. (0=ring, 1=fill&stop)

D Memory Status (0=not full, 1=full)

04: XXXXX PROM signature (0 if bad PROM)
6 06: 0X BATTERY CHECK UNDER LOAD (0=low, 1=OK)
7 07: 00 DISPLAY DATA, Select the Storage Module Area with these codes:

0 Dump pointer to SRP
1 File 1, current file
2 File 2, previous to file 1
3 File 3, previous to file 2
4 File 4, previous to file 3
5 File 5, previous to file 4
7 Display pointer to SRP
9 Oldest data to SRP

1-5 will loop within file boundaries, 0,7,9 allow display to

cross boundaries

07:XXXXXX SM location at end of area selected. Key A to advance to first

data. If another location is keyed in SM will jump to 1st start of
array following that location.
Review data with:

A Advance and display next data point
B Back-up one data point
# Display location, C to return to data
#A Advance to next start of Array
#B Back-up to start of Array
#D Return to ∗9 command mode

8 DUMP TO ANOTHER STORAGE MODULE

08:00 Select Area as in 7 above

01:XXXXXX First Loc. in area selected/Enter Loc. to start dump

02:XXXXXX Final Loc. in area selected/Enter Loc. to end dump

03:XX Enter destination SM address
9 DISPLAY ADDRESSES OF CONNECTED SM

XXXXXXXX 1 = occupied, 0 = unoccupied

87654321 (Addresses 8-1 from left to right)
10 CHANGE ADDRESS

10:0X X is current address, enter address to change to (1-8)

4-6

SECTION 5. TELECOMMUNICATIONS

Telecommunications is used to retrieve data from Final Storage directly to a computer/terminal and to
program the CR510. Any user communication with the CR510 that makes use of a computer or terminal
instead of the CR10KD is through Telecommunications.

Telecommunications can take place over a variety of links including:

• Telephone

• Cellular phone

• Radio frequency

• Short haul modem and twisted pair wire

• SC32A and ribbon cable

• Multi-drop interface and coax cable

This section does not cover the technical interface details for any of these links. Those details are
covered in Section 6 and in the individual manuals for the devices.

Data retrieval can take place in either ASCII or BINARY. The BINARY format is 5 times more compact
than ASCII. The shorter transmission times for binary result in lower long distance costs if the link is
telephone and lower power consumption with an RF link. On "noisy" links shorter blocks of data are
more likely to get through without interruption.

For more efficient data transfer, binary data retrieval makes use of a signature for error detection. The
signature algorithm assures a 99.998% probability that if either the data or its sequence changes, the
signature changes.

Campbell Scientific has developed a software package which automates data retrieval and facilitates the
programming of Campbell Scientific dataloggers and the handling of data files. This package has been
designed to meet the most common needs in datalogger support and telecommunications. Therefore,
this section does not furnish sufficient detail to write telecommunications software. Appendix B contains
some details of binary data transfer and Campbell Scientific's binary data format.

The emphasis of this section is on the commands that a person would use when manually (i.e., keyed in
by hand) interrogating or programming the CR510 via a computer/terminal. These commands and the
responses to them are sent in the American Standard Code for Information Interchange (ASCII).

The telecommunications commands allow the user to perform several operations including:

• monitor data in Input Storage and review data in Final Storage

• retrieve Final Storage data in either ASCII or BINARY

• open communications with the Storage Module

• remote keyboard programming

The Remote Keyboard State (Section 5.2) allows the user with a computer/terminal to use the same
commands as the CR10KD.

5.1 TELECOMMUNICATIONS COMMANDS

When a modem/terminal rings the CR510, the
CR510 should answer almost immediately.
Several carriage returns (CR) must be sent to
the CR510 to allow it to set its baud rate to that
of the modem/terminal (300, 1200, or 9600).
Once the baud rate is set, the CR510 will send
back the prompt, "∗∗∗∗", signaling that it is ready to
receive a command.

GENERAL RULES governing the
telecommunications commands are as follows:

1. ∗∗∗∗ from datalogger means "ready for
command".

2. All commands are of the form: [no.]letter,
where the number may or may not be
optional.

3. Valid characters are the numbers 0-9, the
capital letters A-M, the colon (:), and the
carriage return (CR).

5-1

SECTION 5. TELECOMMUNICATIONS

4. An illegal character increments a counter
and zeros the command buffer, returning a
∗∗∗∗.

5. CR to datalogger means "execute".

6. CRLF from datalogger means "executing
command".

7. ANY character besides a CR sent to the
datalogger with a legal command in its buffer
causes the datalogger to abort the command
sequence with CRLF∗∗∗∗ and to zero the
command buffer.

8. All commands return a response code,
usually at least a checksum.

9. The checksum includes all characters sent by
the datalogger since the last ∗∗∗∗, including the
echoed command sequence, excluding only
the checksum itself. The checksum is
formed by summing the ASCII values, without
parity, of the transmitted characters. The
largest possible checksum value is 8191.
Each time 8191 is exceeded, the CR510
starts the count over; e.g., if the sum of the
ASCII values is 8192, the checksum is 0.

10. Commands that return Campbell Scientific
binary format data (i.e., F and K
commands) return a signature (see
Appendix B.3).

The CR510 sends ASCII data with 8 bits, no
parity, one start bit, and one stop bit.

After the CR510 answers a ring, or completes a
command, it waits about 40 seconds (127
seconds in the Remote Keyboard State) for a
valid character to arrive. It "hangs up" if it does
not receive a valid character in this time interval.
Some modems are quite noisy when not on line;
it is possible for valid characters to appear in
the noise pattern. To insure that this situation
does not keep the CR510 in
telecommunications, the CR510 counts all the
invalid characters it receives from the time it
answers a ring, and terminates communication
after receiving 150 invalid characters.

The CR510 continues to execute its
measurement and processing tasks while
servicing the telecommunication requests. If
the processing overhead is large (short
Execution Interval), the processing tasks will
slow the telecommunication functions. In a
worst case situation, the CR510 interrupts the
processing tasks to transmit a data point every

0.125 second.
The best way to become familiar with the

Telecommunication Commands is to try them
from a terminal connected to the CR510 via the
SC32A (Section 6.7.1) or other interface.
Commands used to interrogate the CR510 in
the Telecommunications Mode are described in
the following Table.

5-2

SECTION 5. TELECOMMUNICATIONS

TABLE 5.1-1. Telecommunications Commands

Command Description

[F.S. Area]A SELECT AREA/STATUS - If 1 or 2 does not precede the A to select the

Final Storage Area, the CR510 will default to Area 1. All subsequent
commands other than A will address the area selected. Datalogger
returns Reference, the DSP location; the number of filled Final Storage
locations; Version of datalogger; Final Storage Area; Location of MPTR
(the location number may be 1 to 7 characters long); Errors #1, #2, and
#3 where #1 is the number of E08's, #2 is the number of overrun errors,
and #3 is the number of times the program stopped due to low voltage
(all are cleared by entering 8888A; #2 is also cleared at time of program
compilation); size of total Memory in CR510; the lithium Battery voltage;
and Checksum. All in the following format:

R+xxxxx F+xxxxx Vxx Axx L+xxxxxxx Exx xx xx Mxxxx B+xxxxx Cxxxx
If data is stored while in telecommunications, the A command must be

issued to update the Reference to the new DSP.

[no. of arrays]B BACK-UP - MPTR is backed-up the specified number of Output Arrays

(no number defaults to 1) and advanced to the nearest start of array.
CR510 sends the Area, MPTR Location, and Checksum:

Ax Lxxxxxxx Cxxxx

[YR:DAY:HR:MM:SS]C RESET/SEND TIME - If time is entered the time is reset. If only 2

colons are in the time string, HR:MM:SS is assumed; 3 colons means
DAY:HR:MM:SS. If only the C is entered, time is unaltered. CR510
returns year, Julian day, hr:min:sec, and Checksum:

Y:xx Dxxxx Txx:xx:xx Cxxxx

[no. of arrays]D ASCII DUMP - If necessary, the MPTR is advanced to start of scan.

CR510 sends the number of arrays specified (no number defaults to 1)
or the number of arrays between MPTR and Reference, whichever is
smaller, CRLF, Location, Checksum.

E End call. Datalogger sends CRLF only.

[no. of loc.]F BINARY DUMP - Used by CSI software for data retrieval. See

Appendix C.

[F.S. loc. no.]G MOVE MPTR - MPTR is moved to specified Final Storage location.

The location number must be entered. CR510 sends Area, Location,
and Checksum: Ax Lxxxxxxx Cxxxx

7H or 2718H REMOTE KEYBOARD - CR510 sends the prompt ">" and is ready to

execute standard keyboard commands (Section OV3).

[loc. no.]I Display/change value at Input Storage location. CR510 sends the value

stored at the location. A new value and CR may then be sent. CR510
sends checksum. If no new value is sent (CR only), the location value
will remain the same.

5-3

SECTION 5. TELECOMMUNICATIONS

3142J TOGGLE FLAGS AND SET UP FOR K COMMAND - Used in the

Monitor Mode and with the Heads Up Display. See Appendix C for
details.

K CURRENT INFORMATION - In response to the K command, the

CR510 sends datalogger time, user flag status, the data at the input
locations requested in the J command, and Final Storage Data if
requested by the J command. Used in the Monitor Mode and with
Heads Up Display. See Appendix B.

[Password]L Unlocks security (if enabled) to the level determined by the password

entered (See ∗C Mode, Section 1.7). CR510 sends security level (0-3)
and checksum: Sxx Cxxxx

[X]M Connect to Storage Module with address 'X' and enter the Storage

Module's Telecommunications Mode (see Storage Module manual).
The Storage Module can also be accessed through the ∗9 Commands
while in the Remote Keyboard (Section 4.5 and the Storage Module
manual).

1N Connect phone modem to RF modem at phone to RF base station

(requires 1200 baud communication).

5.2 REMOTE PROGRAMMING OF THE CR510

Remote programming of the CR510 can be
accomplished with the datalogger support
software or directly through the Remote
Keyboard State.

The datalogger support software was developed
by Campbell Scientific for use with IBM or
compatible PC's. Datalogger programs are
developed on the computer using the program
editor and downloaded to the datalogger with
the terminal emulator program.

The CR510 is placed in the Remote Keyboard
State by sending either "7H" or "2718H" and a
carriage return (CR). The CR510 responds by
sending a CR, line feed (LF), and the prompt '>'.
The CR510 is then ready to receive the standard
keyboard commands; it recognizes all the
standard CR510 keyboard characters plus
several additional characters, including the
decimal point, the minus sign, and Enter (CR)
(Section OV3.2). ENTERING ∗0 RETURNS
THE CR510 TO THE TELECOMMUNICATIONS
COMMAND STATE.

Remember that entering ∗0 will compile and run
the CR510 program if program changes have
been made. If the CR10KD is connected it will
just display "LOG" when ∗0 is executed via
telecommunications. It will not indicate active
tables (keying "∗0" on the Keyboard/Display will
show the tables).

The 7H Command is generally used with a
terminal for direct entry since H makes use of a
destructive backspace and does not send
control Q between each entry. The 2718H
Command functions the same as it does for
other Campbell Scientific dataloggers (deleting
an entry causes the entire entry to be sent,
"control Q" is sent after each user entry).

It is important to remember that the Remote
Keyboard State is still within
Telecommunications. Entering ∗0 exits the
Remote Keyboard State and returns the
datalogger to the Telecommunications
Command State, awaiting another command.
So, the user can step back and forth between
the Telecommunications Command State and
the Remote Keyboard State.

5-4

7H (or 2718H)

Telecommunications Remote

Command Keyboard

State State

∗0

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

6.1 PIN DESCRIPTION

All external communication peripherals connect
to the CR510 through the 9-pin subminiature D­type socket connector located on the front of
the Terminal Strip (Figure 6.1-1). Table 6.1-1
shows the I/O pin configuration, and gives a
brief description of the function of each pin.

TABLE 6.1-1. Pin Description

FIGURE 6.1-1. 9-pin Female Connector

ABR = Abbreviation for the function name.
PIN = Pin number.
O = Signal Out of the CR510 to a
peripheral.
I = Signal Into the CR510 from a
peripheral.

PIN ABR

1 5 V O 5V: Sources 5 VDC, used

2 SG Signal Ground: Provides

3 RING I Ring: Raised by a

4 RXD I Receive Data: Serial

5 ME O Modem Enable: Raised

I/O Description

to power peripherals.

a power return for pin 1
(5V), and is used as a
reference for voltage
levels.

peripheral to put the
CR510 in the
telecommunications
mode.

data transmitted by a
peripheral are received
on pin 4.

when the CR510
determines that a
modem raised the ring
line.

PIN ABR

6 SDE O Synchronous Device

7 CLK/HS I/O Clock/Handshake: Used

8 12 V: Sources

9 TXD O Transmit Data: Serial

I/O Description

Enable: Used to
address Synchronous
Devices (SDs), and can
be used as an enable
line for printers.

with the SDE and TXD
lines to address and
transfer data to SDs.
When not used as a
clock, pin 7 can be used
as a handshake line
(during printer output,
high enables, low
disables).

continuous 12 V, used to
power telephone
modems.

data are transmitted
from the CR510 to
peripherals on pin 9;
logic low marking (0V)
logic high spacing (5V)
standard asynchronous
ASCII, 8 data bits, no
parity, 1 start bit, 1 stop
bit, 300, 1200, 9600,
76,800 baud (user
selectable).

6-1

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

(ME)

MODEM

(COM200

RF95

SC32A)

FIGURE 6.2-1. Hardware Enabled and Synchronously Addressed Peripherals

6.2 ENABLING AND ADDRESSING PERIPHERALS

While several peripherals may be connected in
parallel to the 9-pin port, the CR510 has only
one transmit line (pin 9) and one receive line (pin
4, Table 6.1-1). The CR510 selects a peripheral
in one of two ways: 1) A specific pin is dedicated
to that peripheral and the peripheral is enabled
when the pin goes high; we will call this pin­enabled or simply enabled. 2) The peripheral is
addressed; the address is sent on pin 9, each bit
being synchronously clocked using pin 7. Pin 6
is set high while addressing.

6.2.1 PIN-ENABLED PERIPHERALS

Modem Enable (pin 5) is dedicated to a specific
device. Synchronous Device Enable (pin 6) can
either be used as a Print Enable or it can be
used to address Synchronous Devices (Section

6.6).
Modem Enable (ME), pin 5, is raised to enable

a modem that has raised the ring line.
Modem/terminal peripherals include Campbell
Scientific phone modems and computers or
terminals using the SC32A RS232 interface.
The CR510 interprets a ring interrupt (Section

6.3) to come from a modem if the device raises
the CR510's Ring line, and holds it high until the
CR510 raises the ME line. Only one modem/
terminal may be connected to the CR510.

Print Peripherals are defined as peripherals
which have an asynchronous serial
communications port used to RECEIVE data
transferred by the CR510. In most cases the

print peripheral is a printer, but could also be an
on-line computer or other device.

Synchronous Device Enable (SDE), pin 6, may be
used to enable a print peripheral only when no
other addressable peripherals are connected to
the 9-pin connector. Use of the SDE line as an
enable line maintains CR510 compatibility with
printer-type peripherals which require a line to be
held high (Data Terminal Ready) in order to
receive data.

If output to both a print peripheral and an
addressable peripheral is necessary the SDC99
Synchronous Device Interface is required. With
the SDC99 the print peripheral functions as an
addressable peripheral. If the SDC99 is not
used, the print peripheral receives the address
and data sent to the addressed peripheral.
Synchronous addressing appears as garbage
characters on a print peripheral.

6.2.2 ADDRESSED PERIPHERALS

The CR510 has the ability to address
Synchronous Devices (SDs). SDs differ from
enabled peripherals in that they are not enabled
solely by a hardware line (Section 6.2.1); an SD is
enabled by an address synchronously clocked
from the CR510 (Section 6.6).

Up to 16 SDs may be addressed by the CR510.
Unlike an enabled peripheral, the CR510
establishes communication with an addressed
peripheral before data are transferred. During
data transfer an addressed peripheral uses pin
7 as a handshake line with the CR510.

6-2

Synchronously addressed peripherals include the
CR10KD Keyboard Display, Storage Modules,
SDC99 Synchronous Device Interface (SDC99),
and RF95 RF Modem when configured as a
synchronous device. The SDC99 interface is
used to address peripherals which are normally
pin enabled (Figure 6.2-1).

6.3 RING INTERRUPTS

There are three peripherals that can raise the
CR510's ring line; modems, the CR10KD
Keyboard Display, and the RF Modem
configured for synchronous device for
communication (RF-SDC). The RF-SDC is
used when the CR510 is installed at a
telephone to RF base station.

When the Ring line is raised, the processor is
interrupted, and the CR510 determines which
peripheral raised the Ring line through a process
of elimination (Figure 6.3-1). The CR510 raises
the CLK/HS line forcing all SDs to drop the ring
line. If the ring line is still high the peripheral is a
modem, and the ME line is raised. If the ring line
is low the CR510 addresses the Keyboard
Display and RF-SDC to determine which device
to service. (Section 6.6)

After the CR510 has determined which
peripheral raised the Ring line, the hierarchy is
as follows:

A modem which raises the Ring line will interrupt
and gain control of the CR510. A ring from a
modem aborts data transfer to pin-enabled and
addressed peripherals.

The CR10KD raises the ring line whenever a key
is pressed. The CR10KD will not be serviced
when the modem or RF-SDC is being serviced.

The ring from the CR10KD is blocked when the
SDE line is high, preventing it from interrupting
data transfer to a pin-enabled print device.

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

FIGURE 6.3-1. Servicing of Ring Interrupts

6.4 INTERRUPTS DURING DATA TRANSFER

Instruction 96 is used for on-line data transfer to
peripherals (Section 4.1). Each peripheral
connected to the CR510 requires an Instruction
96 with the appropriate parameter. If the CR510
is already communicating on the 9-pin connector
when Instruction 96 is executed, the instruction
puts the output request in a "queue" and program
execution continues. As the 9-pin connector
becomes available, each device in the queue will
get its turn until the queue is empty.

Instruction 96 is aborted if a modem raises the Ring
line. Data transfer to an addressed peripheral is
aborted if the ring line is raised by a CR10KD or RF
Modem configured as a synchronous device.
Transfer of data is not resumed until the next time
Instruction 96 is executed and the datalogger has
exited telecommunications.

The ∗8 Mode is used to manually initiate data
transfer from Final Storage to a peripheral. An
abort flag is set if any key on the CR10KD or
terminal is pressed during the transfer. Data
transfer is stopped and the memory location
displayed when the flag is set. During ∗8 data
transfer the abort flag is checked as follows:

1. Comma separated ASCII - after every 32
characters.

2. Printable ASCII - after every line.

3. Binary - after every 256 Final Storage locations.

6-3

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

6.5 MODEM/TERMINAL PERIPHERALS

The CR510 considers any device with an
asynchronous serial communications port which
raises the Ring line (and holds it high until the
ME line is raised) to be a modem peripheral.
Modem/terminals include Campbell Scientific
phone modems, and most computers,
terminals, and modems using the SC32A
Optically Isolated RS232 Interface or the SC932
RS232 DCE Interface.

When a modem raises the Ring line, the CR510
responds by raising the ME line. The CR510
must then receive carriage returns until it can
establish baud rate. When the baud rate has
been set, the CR510 sends a carriage return, line
feed, "∗".

The ME line is held high until the CR510 receives
an "E" to exit telecommunications. The ME is
also lowered if a character is not received after 40
seconds in the Telecommunications Command
State (2 minutes in the Remote Keyboard State).

Some modems are quite noisy when not on line; it
is possible for valid characters to appear in the
noise pattern. For this reason, the CR510 counts
all the invalid characters it receives from the time
it answers a ring, and terminates communication
(lowers the ME line and returns to the ∗0 Mode)
after receiving 150 invalid characters.

6.6 SYNCHRONOUS DEVICE COMMUNICATION

The CR510 has the ability to address
Synchronous Devices (SDs). SDs differ from
enabled peripherals (Section 6.2.1) in that they

are not enabled solely by a hardware line. An
SD is enabled by an address synchronously
clocked from the CR510. Up to 16 SDs may be
addressed by the CR510, requiring only three
pins of the 9-pin connector.

Synchronous Device Communication (SDC)
discussed here is for those peripherals which
connect to the 9-pin serial port. (This should
not be confused with Synchronous Device for
Measurement (SDM) peripherals. Although the
communication protocol for SDMs is very
similar, their addressing is independent of SDC
addresses and they do not have a ring line.)

SD STATES
The CR510 and the SDs use a combination of

the Ring, Clock Handshake (CLK/HS) and
Synchronous Device Enable (SDE) lines to
establish communication. The CR510 can put
the SDs into one of six states.

STATE 1, the SD Reset State
The CR510 forces the SDs to the reset/request

state by lowering the SDE and CLK/HS lines.
The SD cannot drive the CLK/HS or RXD lines
in State 1, however, it can raise the Ring line if
service is needed. The SD can never pull the
Ring low if a Modem/Terminal is holding it high.
Data on TXD is ignored by the SD.

STATE 2, the SD Addressing State
The CR510 places the SDs in the addressing

state by raising CLK/HS followed by or
simultaneously raising SDE (Figure 6.6-1). TXD
must be low while SDE and CLK/HS are
changing to the high state.

6-4

FIGURE 6.6-1. Addressing Sequence for the RF Modem

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

State 2 requires all SDs to drop the Ring line
and prepare for addressing. The CR510 then
synchronously clocks 8 bits onto TXD using
CLK/HS as a clock. The least significant bit is
transmitted first and is always logic high. Each
bit transmitted is stable on the rising edge of
CLK/HS. The SDs shift in bits from TXD on the
rising edge of CLK/HS provided by the CR510.
The CR510 can only address one device per
State 2 cycle. More than one SD may respond
to the address, however. State 2 ends when
the 8th bit is received by the SD.

SDs implemented with shift registers decode
the 4 most significant bits (bits 4, 5, 6, and 7) for
an address. Bit 0 is always logic high. Bits 1, 2,
and 3 are optional function selectors or
commands. Addresses established to date are
shown in Table 6.6-1 and are decoded with
respect to the TXD line.

TABLE 6.6-1. SD Addresses

B7 B6 B5 B4 B3 B2 B1 B0
SDC99 Printer 0000XXX1
Storage Module 0001XXX1

CR10KD Keyboard

CR10KD Display00101XX1
RF Modem 0011XXX1

STATE 3, the SD Active State
The SD addressed by State 2, enters State 3.

All other SDs enter State 4. An active SD
returns to State 1 by resetting itself, or by the
CR510 forcing it to reset.

Active SDs have different acknowledgment and
communication protocols. Once addressed, the
SD is free to use the CLK/HS, TXD, and RXD
lines according to its protocol with the CR510.
The CR510 may also pulse the SDE line after
addressing, as long as the CLK/HS and SDE
are not low at the same time.

STATE 4, the SD Inactive State
The SDs not addressed by State 2 enter State

4, if not able to reset themselves (e.g., SM192
Storage Module). Inactive SDs ignore data on
the TXD line and are not allowed to use the
CLK/HS or RXD lines. Inactive SDs may raise
the Ring line to request service.

00100XX1

STATE 5

State 5 is a branch from State 1 when the SDE
line is high and the CLK/HS line is low. The
SDs must drop the Ring line in this state. This
state is not used by SDs. The CR510 must
force the SDs back to the reset state from State
5 before addressing SDs.

STATE 6

State 6 is a branch from State 1, like State 5,
except the SDE line is low and the CLK/HS line
is high. The SDs must drop the Ring line in this
state.

6.7 MODEM/TERMINAL AND COMPUTER REQUIREMENTS

The CR510 considers any device with an
asynchronous serial communications port which
raises the Ring line (and holds it high until the
ME line is raised) to be a modem peripheral.
Modems include Campbell Scientific phone
modems, and most computers, terminals, and
modems using the SC32A Optically Isolated
RS232 Interface.

6.7.1 SC32A INTERFACE TO COMPUTER

Most computers require the SC32A Optically
Isolated RS232 Interface. The SC32A raises
the CR510's ring line when it receives
characters from a modem, and converts the
CR510's logic levels (0 V logic low, 5V logic
high) to RS232 logic levels.

The SC32A 25-pin port is configured as Data
Communications Equipment (DCE) (see Table

6.7-1) for direct connection to Data Terminal
Equipment (DTE), which includes most PCs
and printers.

When the SC32A receives a character from the
terminal/computer (pin 2), 5 V is applied to the
datalogger Ring line (pin 3) for one second or
until the Modem Enable line (ME) goes high.
The CR510 waits approximately 40 seconds to
receive carriage returns, which it uses to
establish baud rate. After the baud rate has
been set the CR510 transmits a carriage return,
line feed, "∗", and enters the Telecommunica­tions Command State (Section 5). If the
carriage returns are not received within the 40
seconds, the CR510 "hangs up".

6-5

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

TABLE 6.7-1. SC32A Pin Description

PIN = Pin number
O = Signal Out of the SC32A to a peripheral
I = Signal Into the SC32A from peripheral

25-PIN FEMALE PORT:
PIN #

1 GROUND
2ITX
3ORX
4 I RTS (POWER)
5OCTS
6ODSR
7 GROUND
8 O DCD
20 I DTR (POWER)

9-PIN MALE PORT:
PIN #

1 +5V INPUT
2 GROUND
3RING
4RX
5ME
6SDE
9TX

NOTE: The SC32A has a jumper, which
when used, passes data only when the ME
line is high and the SDE line is low. The
function of the jumper is to block data sent
to SDs from being received by a
computer/terminal used to initiate data
transfer. Synchronous data will appear as
garbage characters on a computer/terminal.

6.7.2 SC932 INTERFACE TO MODEMS

Most modems have an RS232 port configured
as DCE. For connection to DCE devices such
as modems and some computers, the SC932
9-pin to RS232 DCE Interface should be used.

6.7.3 COMPUTER/TERMINAL REQUIREMENTS

Computer/terminal peripherals are usually
configured as Data Terminal Equipment (DTE).
Pins 4 and 20 are used as handshake lines,
which are set high when the serial port is
enabled. Power for the SC32A RS232 section
is taken from these pins. For equipment
configured as DTE (see Table 6.7-2) a direct
ribbon cable connects the computer/terminal to
the SC32A. Clear to Send (CTS) pin 5, Data
Set Ready (DSR) pin 6, and Data Carrier Detect
(DCD) pin 8 are held high by the SC32A (when
the RS232 section is powered) which should

I/O ABBREVIATION

ABBREVIATION

satisfy hardware handshake requirements of
the computer/terminal.

Table 6.7-2 lists the most common RS232
configuration for Data Terminal Equipment.

TABLE 6.7-2. DTE Pin Configuration

PIN = 25-pin connector number
ABR = Abbreviation for the function name
O = Signal Out of terminal to another device
I = Signal Into terminal from another device

PIN ABR

2 TD O Transmitted Data: Data

3 RD I Received Data: Data is

4 RTS O Request to Send: The

5 CTS I Clear to Send: The

20 DTR O Data Terminal Ready:

6 DSR I Data Set Ready: The

8 DCD I Data Carrier Detect: The

22 RI I Ring Indicator: The

7 SG Signal Ground: Voltages

I/O FUNCTION

is transmitted from the
terminal on this line.

received by the terminal
on this line.

terminal raises this line
to ask a receiving device
if the terminal can
transmit data.

receiving device raises
this line to let the
terminal know that the
receiving device is ready
to accept data.

The terminal raises this
line to tell the modem to
connect itself to the
telephone line.

modem raises this line to
tell the terminal that the
modem is connected to
the phone line.

modem raises this line to
tell the terminal that the
modem is receiving a
valid carrier signal from
the phone line.

modem raises this line to
tell the terminal that the
phone is ringing.

are measured relative to
this point.

6-6

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

FIGURE 6.7-1. Transmitting the ASCII Character 1

6.7.3 COMMUNICATION PROTOCOL/TROUBLE SHOOTING

The ASCII standard defines an alphabet
consisting of 128 different characters where
each character corresponds to a number, letter,
symbol, or control code.

An ASCII character is a binary digital code
composed of a combination of seven "bits", each
bit having a binary state of 1 (one) or 0 (zero).
For example, the binary equivalent for the ASCII
character "1" is 0110001 (decimal 49).

ASCII characters are transmitted one bit at a
time, starting with the 1st (least significant) bit.
During data transmission the marking condition
is used to denote the binary state 1, and the
spacing condition for the binary state 0. The
signal is considered marking when the voltage
is more negative than minus three volts with
respect to ground, and spacing when the
voltage is more positive than plus three volts.

Most computers use 8-bits (1 byte) for data
communications. The 8th bit is sometimes
used for a type of error checking called parity­checking. Even parity binary characters have
an even number of 1's, odd-parity characters
have an odd number of 1's. When parity
checking is used, the 8th bit is set to either a 1
or a 0 to make the parity of the character
correct. The CR510 ignores the 8th bit of a
character that is received, and transmits the 8th
bit as a binary 0. This method is generally
described as "no parity".

To separate ASCII characters, a Start bit is sent
before the 1st bit and a Stop bit is sent after the
8th bit. The start bit is always a space, and the
stop bit is always a mark. Between characters
the signal is in the marking condition.

Figure 6.7-1 shows how the ASCII character "1"
is transmitted. When transmitted by the CR510
using the SC32A RS232 interface spacing and
marking voltages are positive and negative, as

shown. Signal voltages at the CR510 I/O port
are 5V in the spacing condition, and 0V in the
marking condition.

BAUD RATE
BAUD RATE is the number of bits transmitted

per second. The CR510 can communicate at
300, 1200, 9600, and 76,800 baud. In the
Telecommunications State, the CR510 will set
its baud rate to match the baud rate of the
computer/terminal.

Typically the baud rate of the modem/computer/
terminal is set either with dip switches, or
programmed from the keyboard. The instrument's
instruction manual should explain how to set it.

DUPLEX
Full duplex means that two devices can

communicate in both directions simultaneously.
Half duplex means that the two devices must send
and receive alternately. Full duplex should always
be specified when communicating with Campbell
Scientific peripherals and modems. However,
communication between some Campbell Scientific
modems (such as the RF95 RF modem) is carried
out in a half duplex fashion. This can affect the
way commands should be sent to and received
from such a modem, especially when implemented
by computer software.

To overcome the limitations of half duplex,
some communications links expect a terminal
sending data to also write the data to the
screen. This saves the remote device having to
echo that data back. If, when communicating
with a Campbell Scientific device, characters
are displayed twice (in pairs), it is likely that the
terminal is set to half duplex rather than the
correct setting of full duplex.

6-7

SECTION 6. 9-PIN SERIAL INPUT/OUTPUT

IF NOTHING HAPPENS
If the CR510 is connected to the SC32A RS232

interface and a modem/terminal, and an "∗" is
not received after sending carriage returns:

1. Verify that the CR510 has power AT THE
12V AND GROUND INPUTS, and that the
cables connecting the devices are securely
connected.

2. Verify that the port of the modem/terminal is
an asynchronous serial communications
port configured as DTE (see Table 6.7-2).
The most common problems occur when
the user tries to use a parallel port, or
doesn't know the port assignments, i.e.
COM1 or COM2. IBM, and most
compatibles come with a Diagnostic disk
which can be used to identify ports, and
their assignments. If the serial port is
standard equipment, then the operators
manual should give you this information.

3. Verify that there is 5 volts between the
CR510 5V and G terminals. Call Campbell
Scientific technical support if the voltage is
less than 4.8 volts.

Some serial ports, e.g., the Super Serial Card
for Apple computers, can be configured as DTE
or DCE with a jumper block. Pin functions must
match Table 6.7-2.

If you are using a computer to communicate
with the datalogger, communication software
must be used to enable the serial port and to
make the computer function as a terminal. The
port should be enabled for 300, 1200, or 9600
baud, 8 data bits, 1 stop bit, and no parity.
Campbell Scientific's GraphTerm, PC208E,
PC208W, and TCOM provide this function.

If you are not sure that your computer/terminal
is sending or receiving characters, there is a
simple way to verify it. Make sure that the
duplex is set to full. Next, take a paper clip and
connect one end to pin 2, and the other end to
pin 3 of the serial port. Each character typed on
the keyboard will be displayed only if
transmitted from the terminal on pin 2, and
received on pin 3 (if duplex is set to half, the
character will be displayed once if it is not
transmitted, or twice if it is transmitted).

IF GARBAGE APPEARS
If garbage characters appear on the display,

check that the baud rate is supported by the
CR510. If the baud rate is correct, verify that
the computer/terminal is set for 8 data bits, and
no parity. Garbage will appear if 7 data bits and
no parity are used. If the computer/terminal is
set to 8 data bits and even or odd parity,
communication cannot be established.

6-8

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

This section gives some examples of Input Programming for common sensors used with the CR510.
These examples detail only the connections, Input, Program Control, and Processing Instructions
necessary to perform measurements and store the data in engineering units in Input Storage. Output
Processing Instructions are omitted (see Section 8 for some processing and program control examples).
It is left to the user to program the necessary instructions to obtain the final data in the form desired. No
output to final storage will take place without additional programming.

The examples given in this section would likely be only fragments of larger programs. In general, the
examples are written with the measurements made by the lowest numbered channels, the instructions at
the beginning of the program table, and low number Input Storage Locations used to store the data. It is
unlikely that an application and CR510 configuration exactly duplicates that assumed in an example.

These examples are not meant to be used verbatim; sensor calibration, input channels, and input
locations must be adjusted for the actual circumstances. Unless otherwise noted, all excitation channels
are switched analog output.

7.1 SINGLE ENDED VOLTAGE

107 TEMPERATURE PROBE

Instruction 11 excites Campbell Scientific's 107
Thermistor Probe with a 2 VAC excitation, makes a
single ended measurement and calculates
temperature (°C) with a fifth order polynomial. In this
example, the temperatures are obtained from three
107 probes. The measurements are made on single­ended channels 1-3 and the temperatures are stored in
Input Locations 1-3.

CONNECTIONS
The black leads from the probes go to

excitation channel 1, the purple leads go to
analog ground (AG), the clear leads go to
ground (G), and the red leads go to single­ended channels 1, 2, and 3 (channel 1H,
channel 1L, and channel 2H, respectively).

PROGRAM

01: Temp (107) (P11)

1: 3 Reps
2: 1 SE Channel
3: 1 Excite all reps w/E1
4: 1 Loc [ 107_T_1 ]
5: 1 Mult
6: 0 Offset

7.2 DIFFERENTIAL VOLTAGE

MEASUREMENT

output is referenced to the sensor ground. The
associated current drain usually requires a
power source external to the CR510. A typical
connection scheme where AC power is not
available and both the CR510 and sensor are
powered by an external battery is shown in
Figure 7.2-1. Since a single-ended
measurement is referenced to the CR510
ground, any voltage difference between the
sensor ground and CR510 ground becomes a
measurement error. A differential measurement
avoids this error by measuring the signal
between the 2 leads without reference to ground.
This example analyzes the potential error on a
differential CO
CO

The wire used to supply power from the external
battery is 18 AWG with an average resistance of

6.5 ohms/1000 ft. The power leads to the CR510
and LI-6262 are 2 ft and 10 ft, respectively.
Typical current drain for the LI-6262 is 1000 mA.
When making measurements, the CR510 draws
about 35 mA. Since voltage is equal to current
multiplied by resistance (V=IR), ground voltages
at the LI-6262 and the CR510 relative to battery
ground are:

O analyzer, model LI-6262.

2/H2

1A ∗ 6.5 ohms/1000 ft ∗ 10 ft = +0.065 V

measurement using a LI-COR

2

LI-6262 ground =

Some sensors either contain or require active
signal conditioning circuitry to provide an easily
measured analog voltage output. Generally, the

CR510 ground =

0.035A ∗ 6.5 ohms/1000 ft ∗ 2 ft = +0.0005 V

7-1

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

CR510

FIGURE 7.2-1. Typical Connection for Active Sensor with External Battery

Ground at the LI-6262 is 0.065 V higher than ground
at the CR510. The LI-6262 can be programmed to
output a linear voltage (0 to 100 mV) that is
proportional to differential CO
scale, or 1 µmol/mol/mV. If the output is measured
with a single-ended voltage measurement, it is

0.065 V or 65 µmol/mol high. If this offset remained

constant, it could be corrected in programming.
However, it is better to use a differential voltage
measurement which does not rely on the current
drain remaining constant. The program that follows
illustrates the use of Instruction 2 to make the
measurement. A multiplier of 1 is used to convert
the millivolt output into µmol/mol.

PROGRAM

01: Volt (Diff) (P2)

1: 1 Reps
2: 25 ±2500 mV 60 Hz Rejection

Range
3: 1 DIFF Channel
4: 1 Loc [ umol_mol ]
5: 1 Mult
6: 0 Offset

, 100 µmol/mol full

2

7.3 HMP45C TEMPERATURE AND RH PROBE

Instruction 11 (107 Probe) is used to measure
the temperature portion of the HMP45C Probe.
It makes a single ended voltage measurement,
and calculates temperature with a fifth order
polynomial. A multiplier of 1.0 and offset of 0.0
yields temperature in degrees Celsius.

Instruction 4 is used to measure relative
humidity. It provides an excitation voltage to
power the RH sensor. A 150 millisecond delay
is allowed for warm-up before the single-ended
measurement is made.

The probe has an output of 0 to 100 millivolts
for the 0 to 100% RH range, a multiplier of 0.1
and an offset of 0.0 provides relative humidity in
percent.

This example uses Control Port 1 to power the
RH sensor.

CONNECTIONS
The HMP45C probe is measured by two single-

ended analog input channels. The green (RH)
and the orange (temperature) leads are
connected to either a HI or LO input. The black
thermistor excitation lead connects to any
excitation channel. The yellow lead powers the
RH sensor via control port 1. The white and
purple leads connect to Analog Ground (AG).
The clear lead is the shield which connects to
Ground (G) on the CR510.

01: Temp (107) (P11)

1: 1 Reps
2: 1 SE Channel
3: 1 Excite all reps w/E1
4: 1 Loc [ air_temp ]
5: 1.0 Mult
6: 0.0 Offset

7-2

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

02: Do (P86)

1: 41 Set Port 1 High

03: Excitation with Delay (P22)

1: 2 Ex Channel
2: 0 Delay w/Ex (units = 0.01 sec)
3: 15 Delay after Ex (units = 0.01

sec)

4: 0 mV Excitation

04: Volts (SE) (P1)

1: 1 Reps
2: 5 2500 mV Slow Range
3: 2 SE Channel
4: 2 Loc [ RH ]
5: .1 Mult
6: 0 Offset

05: Do (P86)

1: 51 Set Port 1 Low

7.4 ANEMOMETER WITH PHOTOCHOPPER OUTPUT

An anemometer with a photochopper
transducer produces a pulse output which is
measured by the CR510's Pulse Count
Instruction. The Pulse Count Instruction with a
Configuration Code of 20, measures "high
frequency pulses", "discards data from
excessive intervals", and "outputs the reading
as a frequency" (Hz = pulses per second). The
frequency output is the only output option that is
independent of the scan rate.

The anemometer used in this example is the R. M.
Young Model 12102D Cup Anemometer, with a 10

window chopper wheel. The photochopper
circuitry is powered from the CR510 12 V supply;
AC power or back-up batteries should be used to
compensate for the increased current drain.

Wind speed is desired in meters per second
(m/s). There is a pulse each time a window in
the chopper wheel, which revolves with the
cups, allows light to pass from the source to the
photoreceptor. Because there are 10 windows
in the chopper wheel, there are 10 pulses per
revolution. Thus, 1 revolution per minute (rpm)
is equal to 10 pulses per 60 seconds (1 minute)
or 6 rpm = 1 pulse per second (Hz). The
manufacturer's calibration for relating wind
speed to rpm is:

Wind(m/s) =

(0.01632 m/s)/rpm ∗ Xrpm + 0.2 m/s

The result of the Pulse Count Instruction
(Configuration Code = 20) is X pulses per sec.
(Hz). The multiplier and offset to convert XHz to
meters per second are: Wind (m/s) = (0.01632
m/s)/rpm x (6 rpm/Hz) x XHz + 0.2 m/s

Wind (m/s) =

(0.09792 m/s)/Hz x XHz + 0.2 m/s

PROGRAM

01: Pulse (P3)

1: 1 Reps
2: 1 Pulse Input Channel
3: 20 High Frequency, Output Hz
4: 10 Loc [ WS_mph ]
5: .09792 Mult
6: .2 Offset

CR510

FIGURE 7.4-1. Wiring Diagram for Anemometer

7-3

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

CR510

FIGURE 7.5-1. Wiring Diagram for Rain Gage with Long Leads

7.5 TIPPING BUCKET RAIN GAGE WITH LONG LEADS

A tipping bucket rain gage is measured with the
Pulse Count Instruction configured for Switch
Closure. Counts from long intervals will be
used, as the final output desired is total rainfall
(obtained with Instruction 72, Totalize). If
counts from long intervals were discarded, less
rainfall would be recorded than was actually
measured by the gage (assuming there were
counts in the long intervals). Output is desired
in millimeters of precipitation. The gage is
calibrated for a 0.01 inch tip, therefore, a
multiplier of 0.254 is used.

In a long cable there is appreciable capacitance
between the lines. The capacitance is
discharged across the switch when it closes. In
addition to shortening switch life, a transient
may be induced in other wires packaged with
the rain gage leads each time the switch closes.
The 100 ohm resistor protects the switch from
arcing and the associated transient from
occurring, and should be included any time
leads longer than 100 feet are used with a
switch closure.

NOTE: The TE525 and TE525MM
raingages from CSI always have this
resistor insta lled.

PROGRAM

01: Pulse (P3)

1: 1 Reps
2: 1 Pulse Input Channel
3: 2 Switch Closure, All Counts
4: 11 Loc [ Precip_mm ]
5: .254 Mult
6: 0 Offset

7.6 100 OHM PRT IN 4 WIRE HALF BRIDGE

Instruction 9 is the best choice for accuracy
where the Platinum Resistance Thermometer
(PRT) is separated from other bridge
completion resistors by a lead length having
more than a few thousandths of an ohm
resistance. In this example, it is desired to
measure a temperature in the range of -10 to
40°C. The length of the cable from the CR510
to the PRT is 500 feet.

Figure 7.6-1 shows the circuit used to measure
the PRT. The 10 kohm resistor allows the use
of a high excitation voltage and low voltage
ranges on the measurements. This insures that
noise in the excitation does not have an effect
on signal noise. Because the fixed resistor (R
and the PRT (R
resistance, the differential measurement of the
voltage drop across the PRT can be made on
the same range as the differential measurement
of the voltage drop across R

If the voltage drop across the PRT (V
under 50 mV, self heating of the PRT should be
less than 0.001°C in still air. The best
resolution is obtained when the excitation
voltage is large enough to cause the signal
voltage to fill the measurement voltage range.
The resolution of this measurement on the
25mV range is +0.04°C. The voltage drop
across the PRT is equal to V
ratio of R

s

greatest when R
at 40°C). To find the maximum excitation
voltage that can be used, we assume V
to 25 mV and use Ohm's Law to solve for the
resulting current, I.

) have approximately the same

s

.

f

2

multiplied by the

x

to the total resistance, and is

is greatest (Rs=115.54 ohms

s

) is kept

equal

2

)

f

7-4

I = 25 mV/R

= 25 mV/115.54 ohms = 0.216 mA

s

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

Next solve for V

:

x

V

= I(R1+Rs+Rf) = 2.21 V

x

If the actual resistances were the nominal
values, the CR510 would not over range with V
= 2.2 V. To allow for the tolerances in the actual
resistances, it is decided to set V

equal to 2.1

x

volts (e.g., if the 10 kohms resistor is 5% low,
then R

/(R1+Rs+Rf)=115.54/9715.54, and V

s

x

must be 2.102 V to keep Vs less than 25 mV).
The result of Instruction 9 when the first

differential measurement (V
the 2.5 V range is equivalent to R

) is not made on

1

s/Rf

.
Instruction 16 computes the temperature (°C)
for a DIN 43760 standard PRT from the ratio of
the PRT resistance at the temperature being
measured to its resistance at 0°C (R
Thus, a multiplier of R

is used in Instruction

f/R0

9 to obtain the desired intermediate, R

s/R0

s/R0

).

(=Rs/Rf x Rf/Ro). If Rs and R0 were each
exactly 100 ohms, the multiplier would be 1.
However, neither resistance is likely to be exact.
The correct multiplier is found by connecting the
PRT to the CR510 and entering Instruction 9
with a multiplier of 1. The PRT is then placed in
an ice bath (@ 0°C; R

), and the result of

s=R0

the bridge measurement is read using the ∗6
Mode. The reading is R

since Rs=Ro. The correct value of the

R

o/Rf

multiplier, R

, is the reciprocal of this

f/R0

, which is equal to

s/Rf

reading. The initial reading assumed for this
example was 0.9890. The correct multiplier is:

= 1/0.9890 = 1.0111.

R

f/R0

The fixed 100 ohm resistor must be thermally
stable. Its precision is not important because
the exact resistance is incorporated, along with
that of the PRT, into the calibrated multiplier.
The 10 ppm/°C temperature coefficient of the

x

fixed resistor will limit the error due to its change
in resistance with temperature to less than

0.15°C over the specified temperature range.
Because the measurement is ratiometric

), the properties of the 10 kohm resistor

(R

s/Rf

do not affect the result.
A terminal input module (Model 4WPB100) can

be used to complete the circuit shown in Figure

7.8-1.

PROGRAM

01: Full Bridge w/mv Excit (P9)

1: 1 Reps
2: 23 ±25 mV 60 Hz Rejection

Ex Range

3: 23 ±25 mV 60 Hz Rejection

Br Range
4: 1 DIFF Channel
5: 1 Excite all reps w/Exchan 1
6:2100 mV Excitation
7: 1 Loc [ Rs_Ro ]
8: 1.0111 Mult
9: 0 Offset

02: Temperature RTD (P16)

1: 1 Reps
2: 1 R/Ro Loc [ Rs_Ro ]
3: 2 Loc [ Temp_C ]
4: 1 Mult
5: 0 Offset

CR510

FIGURE 7.6-1. Wiring Diagram for PRT in 4 Wire Half Bridge

7-5

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

7.7 100 OHM PRT IN 3 WIRE HALF BRIDGE

The temperature measurement requirements in
this example are the same as in Section 7.8. In
this case, a three wire half bridge, Instruction 7,
is used to measure the resistance of the PRT.
The diagram of the PRT circuit is shown in Fig.

7.7-1.
As in the example in Section 7.8, the excitation

voltage is calculated to be the maximum
possible, yet allow the +25 mV measurement
range. The 10 kohm resistor has a tolerance of
±1%; thus, the lowest resistance to expect from
it is 9.9 kohms. We calculate the maximum
excitation voltage (V
across the PRT less than 25 mV:

0.025V > V

The excitation voltage used is 2.1 V.
The multiplier used in Instruction 7 is

determined in the same manner as in Section

7.8. In this example, the multiplier (R
assumed to be 100.93.

) to keep the voltage drop

x

115.54/(9900+115.54);

x

< 2.17 V

V

x

f/R0

) is

resistance is 2%, but is more likely to be on the
order of 1%. The resistance of R
with Instruction 7, is actually R

calculated

s

plus the

s

difference in resistance of wires A and B. The
average resistance of 22 AWG wire is 16.5
ohms per 1000 feet, which would give each 500
foot lead wire a nominal resistance of 8.3 ohms.
Two percent of 8.3 ohms is 0.17 ohms.
Assuming that the greater resistance is in wire
B, the resistance measured for the PRT (R

=

0

100 ohms) in the ice bath would be 100.17
ohms, and the resistance at 40°C would be

115.71. The measured ratio R

is 1.1551;

s/R0

the actual ratio is 115.54/100 = 1.1554. The
temperature computed by Instruction 16 from
the measured ratio would be about 0.1°C lower
than the actual temperature of the PRT. This
source of error does not exist in the example in
Section 7.8, where a 4 wire half bridge is used
to measure PRT resistance.

The advantages of the 3 wire half bridge are
that it only requires 3 lead wires going to the
sensor and takes 2 single-ended input
channels, whereas the 4 wire half bridge
requires 4 wires and 2 differential channels.

A terminal input module (Model 3WHB10K) can
be used to complete the circuit in Figure 7.7-1.

The 3 wire half bridge compensates for lead
wire resistance by assuming that the resistance
of wire A is the same as the resistance of wire
B. The maximum difference expected in wire

CR510

FIGURE 7.7-1. 3 Wire Half Bridge Used to Measure 100 ohm PRT

7-6

E1

CR510

H1

L1

AG

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

FIGURE 7.8-1. Full Bridge Schematic for 100 ohm PRT

PROGRAM

01: 3W Half Bridge (P7)

1: 1 Reps
2: 23 ±25 mV 60 Hz Rejection

Range
3: 1 SE Channel
4: 1 Excite all reps w/Exchan 1
5:2100 mV Excitation
6: 1 Loc [ Rs_Ro ]
7: 100.93 Mult
8: 0 Offset

02: Temperature RTD (P16)

1: 1 Reps
2: 1 R/Ro Loc [ Rs_Ro ]
3: 2 Loc [ Temp_C ]
4: 1 Mult
5: 0 Offset

7.8 100 OHM PRT IN 4 WIRE FULL BRIDGE

This example describes obtaining the
temperature from a 100 ohm PRT in a 4 wire
full bridge (Instruction 6). The temperature
being measured is in a constant temperature
bath and is to be used as the input for a control
algorithm. The PRT in this case does not
adhere to the DIN standard (alpha = 0.00385)
used in the temperature calculating Instruction

16. Alpha is defined as ((R
where R

and R0 are the resistances of the

100

PRT at 100°C and 0°C, respectively. In this
PRT alpha is equal to 0.00392.

The result given by Instruction 6 (X) is 1000

(where Vs is the measured bridge output

V

s/Vx

voltage, and V

is the excitation voltage) which

x

is:

X = 1000 (R

/(Rs+R1)-R3/(R2+R3))

s

100/R0

)-1)/100,

The resistance of the PRT (R

) is calculated

s

with the Bridge Transform Instruction 59:

= R1 X'/(1-X')

R

s

Where

X' = X/1000 + R

Thus, to obtain the value R

/(R2+R3)

3

, (R0 = Rs @

s/R0

0°C) for the temperature calculating Instruction
16, the multiplier and offset used in Instruction 6
are 0.001 and R
multiplier used in Instruction 59 to obtain R

/(R2+R3), respectively. The

3

s/R0

is R1/R0 (5000/100 = 50).
It is desired to control the temperature bath at

50°C with as little variation as possible. High
resolution is needed so that the control
algorithm will be able to respond to minute
changes in temperature. The highest resolution
is obtained when the temperature range results
in an output voltage (V

) range which fills the

s

measurement range selected in Instruction 6.
The full bridge configuration allows the bridge to
be balanced (V

= 0V) at or near the control

s

temperature. Thus, the output voltage can go
both positive and negative as the bath
temperature changes, allowing the full use of
the measurement range.

The resistance of the PRT is approximately

119.7 ohms at 50°C. The 120 ohm fixed
resistor balances the bridge at approximately
51°C. The output voltage is:

= Vx [Rs/(Rs+R1) - R3/(R2+R3)]

V

s

= Vx [R

/(Rs+5000) - 0.023438]

s

The temperature range to be covered is ±50
±10°C. At 40°C R

is approximately 115.8

s

ohms, or:

= -8.0224x10-4 V

V

s

x

7-7

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

Even with an excitation voltage (V
mV, V

can be measured on the +2.5 mV scale

s

) equal to 2500

x

(40°C = 115.8 ohms = -2.006 mV, 60°C = 123.6
ohms = 1.714 mV). There is a change of
approximately 2 mV from the output at 40°C to the
output at 51°C, or 181 µV/°C. With a resolution of

0.33 µV on the 2.5 mV range, this means that the
temperature resolution is 0.0018°C.

The 5 ppm per °C temperature coefficient of the
fixed resistors was chosen so that their 0.01%
accuracy tolerance would hold over the desired
temperature range.

The relationship between temperature and PRT
resistance is slightly nonlinear one. Instruction
16 computes this relationship for a DIN
standard PRT where the nominal temperature
coefficient is 0.00385/°C. The change in
nonlinearity of a PRT with the temperature
coefficient of 0.00392/°C is minute compared
with the slope change. Entering a slope
correction factor of 0.00385/0.00392 = 0.98214
as the multiplier in Instruction 16 results in a
calculated temperature which is well within the
accuracy specifications of the PRT.

PROGRAM

01: Full Bridge (P6)

1: 1 Reps
2: 21 ±2.5 mV 60 Hz Rejection

Range
3: 1 DIFF Channel
4: 1 Excite all reps w/Exchan 1
5:2500 mV Excitation
6: 11 Loc [ Rs_Ro ]
7: .001 Mult
8: .02344 Offset

02: BR Transform Rf[X/(1-X)] (P59)

1: 1 Reps
2: 11 Loc [ Rs_Ro ]
3: 50 Multiplier (Rf)

03: Temperature RTD (P16)

1: 1 Reps
2: 11 R/Ro Loc [ Rs_Ro ]
3: 12 Loc [ Temp_C ]
4: .98214 Mult
5: 0 Offset

7.9 PRESSURE TRANSDUCER - 4 WIRE FULL BRIDGE

This example describes a measurement made
with a Druck PDCR 1230 depth measurement
pressure transducer. The pressure transducer
was ordered for use with 5 volt positive or negative
excitation and has a range of 5 psi or about 3.5
meters of water. The transducer is used to
measure the depth of water in a stilling well.

Instruction 6, 4 Wire Full Bridge, is used to
measure the pressure transducer. The high output
of the semiconductor strain gage necessitates the
use of the 25 mV input range. The sensor is
calibrated by connecting it to the CR510 and using
Instruction 6, an excitation voltage of 2500 mV, a
multiplier of 1 and an offset of 0, noting the
readings (∗6 Mode) with 10 cm of water above the
sensor and with 334.6 cm of water above the
sensor. The output of Instruction 6 is 1000 V
or millivolts per volt excitation. At 10 cm the
reading is 0.19963 mV/V and at 334.6 cm the
reading is 6.6485 mV/V. The multiplier to yield
output in cm is:

(334.6 - 10)/(6.6485-.19963) =

50.334 cm/mV/V

The offset is determined after the pressure
transducer is installed in the stilling well. The
sensor is installed 65 cm below the water level
at the time of installation. The depth of water at
this time is determined to be 72.6 cm relative to
the desired reference. When programmed with
the multiplier determined above and an offset of
0, a reading of 65.12 is obtained. The offset for
the actual measurements is thus determined to
be 72.6 - 65.12 = 7.48 cm.

The lead length is approximately 10 feet, so
there is no appreciable error due to lead wire
resistance.

PROGRAM

01: Full Bridge (P6)

1: 1 Reps
2: 23 ±25 mV 60 Hz Rejection

Range
3: 1 DIFF Channel
4: 1 Excite all reps w/Exchan 1
5:2500 mV Excitation
6: 1 Loc [ HT_cm ]
7: 50.334 Mult
8: 7.48 Offset

s/Vx

7-8

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

CR510

FIGURE 7.9-1. Wiring Diagram for Full Bridge Pressure Transducer

FIGURE 7.10-1. Lysimeter Weighing Mechanism

7.10 LYSIMETER - 6 WIRE FULL BRIDGE

When a long cable is required between a load cell
and the CR510, the resistance of the wire can
create a substantial error in the measurement if
the 4 wire full bridge (Instruction 6) is used to
excite and measure the load cell. This error arises
because the excitation voltage is lower at the load
cell than at the CR510 due to voltage drop in the
cable. The 6 wire full bridge (Instruction 9) avoids
this problem by measuring the excitation voltage at
the load cell. This example shows the errors one
would encounter if the actual excitation voltage
was not measured and shows the use of a 6 wire
full bridge to measure a load cell on a weighing
lysimeter (a container buried in the ground, filled
with plants and soil, used for measuring
evapotranspiration).

The lysimeter is 2 meters in diameter and 1.5
meters deep. The total weight of the lysimeter
with its container is approximately 8000 kg. The
lysimeter has a mechanically adjustable counter­balance, and changes in weight are measured
with a 250 pound (113.6 kg) capacity Sensotec

Model 41 tension/compression load cell. The
load cell has a 4:1 mechanical advantage on the
lysimeter (i.e., a change of 4 kg in the mass of the
lysimeter will change the force on the load cell by
1 kg-force or 980 N).

2

The surface area of the lysimeter is 3.1416 m
31,416 cm

2

, so 1 cm of rainfall or evaporation

or

results in a 31.416 kg change in mass. The load
cell can measure ±113.6 kg, a 227 kg range. This
represents a maximum change of 909 kg (28 cm of
water) in the lysimeter before the counterbalance
would have to be readjusted.

There is 1000 feet of 22 AWG cable between the
CR510 and the load cell. The output of the load cell
is directly proportional to the excitation voltage.
When Instruction 6 (4 wire half bridge) is used, the
assumption is that the voltage drop in the
connecting cable is negligible. The average
resistance of 22 AWG wire is 16.5 ohms per 1000
feet. Thus, the resistance in the excitation lead
going out to the load cell added to that in the lead
coming back to ground is 33 ohms. The resistance

7-9

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

of the bridge in the load cell is 350 ohms. The
voltage drop across the load cell is equal to the
voltage at the CR510 multiplied by the ratio of the
load cell resistance, R

, to the total resistance, RT,

s

of the circuit. If Instruction 6 were used to measure
the load cell, the excitation voltage actually applied
to the load cell, V

V

= Vx Rs/RT = Vx 350/(350+33) = 0.91 V

1

, would be:

1

x

Where Vx is the excitation voltage. This means
that the voltage output by the load cell would only
be 91% of that expected. If recording of the
lysimeter data was initiated with the load cell
output at 0 volts, and 100 mm of evapotranspira­tion had occurred, calculation of the change with
Instruction 6 would indicate that only 91 mm of
water had been lost. Because the error is a fixed
percentage of the output, the actual magnitude of
the error increases with the force applied to the
load cell. If the resistance of the wire was
constant, one could correct for the voltage drop
with a fixed multiplier. However, the resistance of
copper changes 0.4% per degree C change in
temperature. Assume that the cable between the
load cell and the CR510 lays on the soil surface
and undergoes a 25°C diurnal temperature
fluctuation. If the resistance is 33 ohms at the
maximum temperature, then at the minimum
temperature, the resistance is:

(1-25x0.004)33 ohms = 29.7 ohms

The actual excitation voltage at the load cell is:

= 350/(350+29.7) Vx = .92 V

V

1

x

The excitation voltage has increased by 1%,
relative to the voltage applied at the CR510. In

the case where we were recording a 91 mm
change in water content, there would be a 1 mm
diurnal change in the recorded water content that
would actually be due to the change in
temperature. Instruction 9 solves this problem by
actually measuring the voltage drop across the
load cell bridge. The drawbacks to using
Instruction 9 are that it requires an extra
differential channel and the added expense of a 6
wire cable. In this case, the benefits are worth
the expense.

The load cell has a nominal full scale output of 3
millivolts per volt excitation. If the excitation is 2.5
volts, the full scale output is 7.5 millivolts; thus, the
±7.5 millivolt range is selected. The calibrated
output of the load cell is 3.106 mV/V

at a load of

1

250 pounds. Output is desired in millimeters of
water with respect to a fixed point. The "4" found
in equation 7.12-1 is due to the mechanical
advantage. The calibration in mV/V

3.106 mV/V

/250 lb x 2.2 lb/kg x

1

3.1416 kg/mm/4 = 0.02147 mV/V

/mm is :

1

/mm

1

The reciprocal of this gives the multiplier to
convert mV/V

into millimeters. (The result of

1

Instruction 9 is the ratio of the output voltage to
the actual excitation voltage multiplied by 1000,
which is mV/V

1/0.02147 mV/V

):

1

/mm = 46.583 mm/mV/V

1

1

The output from the load cell is connected so
that the voltage increases as the mass of the
lysimeter increases. (If the actual mechanical
linkage was as shown in Figure 7.10-1, the
output voltage would be positive when the load
cell was under tension.)

7-10

CR510

FIGURE 7.10-2. 6 Wire Full Bridge Connection for Load Ce ll

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

When the experiment is started, the water content
of the soil in the lysimeter is approximately 25% on
a volume basis. It is decided to use this as the
reference (i.e., 0.25 x 1500 mm = 375 mm). The
experiment is started at the beginning of what is
expected to be a period during which
evapotranspiration exceeds precipitation.
Instruction 9 is programmed with the correct
multiplier and no offset. After hooking everything
up, the counterbalance is adjusted so that the load
cell is near the top of its range; this will allow a
longer period before readjustment is necessary.
The result of Instruction 9 (monitored with the ∗6
Mode) is 109. The offset needed to give the
desired initial value of 375 mm is 266. However, it
is decided to add this offset in a separate
instruction so the result of Instruction 9 can be
used as a ready reminder of the strain on the load
cell (range = ±140 mm). When the strain on the
load cell nears its rated limits, the counterbalance
is readjusted and the offset recalculated to provide
a continuous record of the water budget.

The program table has an execution interval of 10
seconds. The average value in millimeters is output
to Final Storage (not shown in Table) every hour.
The average is used, instead of a sample, in order to
cancel out effects of wind loading on the lysimeter.

PROGRAM

01: Full Bridge w/mv Excit (P9)

1: 1 Reps
2: 25 ±2500 mV 60 Hz

Rejection Ex Range

3: 22 ±7.5 mV 60 Hz Rejection

Br Range
4: 1 DIFF Channel
5: 1 Excite all reps w/Exchan 1
6:2500 mV Excitation
7: 1 Loc [ Raw_mm ]
8: 46.583 Mult
9: 0 Offset

02: Z=X+F (P34)

1: 1 X Loc [ Raw_mm ]
2: 266 F
3: 2 Z Loc [ mm_H2O ]

7.11 227 GYPSUM SOIL MOISTURE BLOCK

Soil moisture is measured with a gypsum block by
relating the change in moisture to the change in
resistance of the block. An AC Half Bridge
(Instruction 5) is used to determine the resistance
of the gypsum block. Rapid reversal of the
excitation voltage inhibits polarization of the
sensor. Polarization creates an error in the output
so the fast integration option is used. The output
of Instruction 5 is the ratio of the output voltage to
the excitation voltage; this output is converted to
gypsum block resistance with Instruction 59,
Bridge Transform.

The Campbell Scientific 227 Soil Moisture Block
uses a Delmhorst gypsum block with a 1 kohm
bridge completion resistor. Using data supplied by
Delmhorst, Campbell Scientific has computed
coefficients for a 5th order polynomial to convert
block resistance to water potential in bars. There
are two polynomials: one to optimize the range from

-0.1 to -2 bars, and one to cover the range from -0.1
to -10 bars (the minus sign is omitted in the output).
The -0.1 to -2 bar polynomial requires a multiplier of
1 in the Bridge Transform Instruction (result in
kohms) and the -0.1 to -10 bar polynomial requires a
multiplier of 0.1 (result in 10,000s of ohms). The
multiplier is a scaling factor to maintain the
maximum number of significant digits in the
polynomial coefficients.

In this example, we wish to make measurements
on four gypsum blocks and output the final data in
bars. The soil where the moisture measurements
are to be made is quite wet at the time the data
logging is initiated, but is expected to dry beyond
the -2 bar limit of the wet range polynomial. The
dry range polynomial is used, so a multiplier of 0.1
is entered in the bridge transform instruction.

When the water potential is computed, it is
written over the resistance value. The
potentials are stored in Input Locations 1-4
where they may be accessed for output to Final
Storage. If it was desired to retain the
resistance values, the potential measurements
could be stored in Locations 5-8 by changing
the value in Parameter 3 to 7 in Instruction 55.

7-11

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

CR510

FIGURE 7.11-1. 6 227 Gypsum Blocks Connected to the CR510
PROGRAM

01: AC Half Bridge (P5)

1: 4 Reps
2: 15 ±2500 mV Fast Range
3: 1 SE Channel
4: 1 Ex Channel Option
5:2500 mV Excitation
6: 1 Loc [ H2O_bar_1 ]
7: 1 Mult
8: 0 Offset

02: BR Transform Rf[X/(1-X)] (P59)

1: 4 Reps
2: 1 Loc [ H2O_bar_1 ]
3: .1 Multiplier (Rf)

03: Polynomial (P55)

1: 4 Reps
2: 1 X Loc [ H2O_bar_1 ]
3: 1 F(X) Loc [ H2O_bar_1 ]
4: .15836 C0
5: 6.1445 C1
6: -8.4189 C2
7: 9.2493 C3
8: -3.1685 C4
9: .33392 C5

7.12 NONLINEAR THERMISTOR IN HALF BRIDGE

Instruction 11, 107 Thermistor Probe, automatically
linearizes the output of a nonlinear thermistor, 107
Probe, by transforming the millivolt reading with a 5th
order polynomial. Instruction 55, Polynomial, can be
used to calculate temperature of any nonlinear
thermistor, provided the correlation between
temperature and probe output is known, and an
appropriate polynomial fit has been determined. In
this example, the CR510 is used to measure the

temperature of four 101 Probes (used with the CR21
but usually not the CR510). Instruction 4, Excite,
Delay, and Measure, is used because the high
source resistance of the probe requires a long input
settling time (Section 10.3.1). The excitation voltage
is 2000 mV, the same as used in the CR21. The
signal voltage is then transformed to temperature
using the Polynomial Instruction.

The manual for the 101 Probe gives the coefficients
of the 5th order polynomial used to convert the
output in millivolts to temperature (E denotes the
power of 10 by which the mantissa is multiplied):

C0 -53.7842
C1 0.147974
C2 -2.18755E-4
C3 2.19046E-7
C4 -1.11341E-10
C5 2.33651E-14

The CR510 will only allow 5 significant digits to the
right or left of the decimal point to be entered from the
keyboard. The polynomial cannot be applied exactly
as given in the 101 manual. The initial millivolt
reading must be scaled if the coefficients of the higher
order terms are to be entered with the maximum
number of significant digits. If 0.001 is used as a
multiplier on the millivolt output, the coefficients are
divided by 0.001 raised to the appropriate power (i.e.,
C0=C0, C1=C1/0.001, C2=C2/.000001, etc.). With
this adjustment, the coefficients entered in
Parameters 4-9 of Instruction 55 become:

C0 -53.784
C1 147.97
C2 -218.76
C3 219.05
C4 -111.34
C5 23.365

7-12

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

CR510

FIGURE 7.12-1. Nonlinear Thermistor Probes Connected to CR510

PROGRAM

01: Excite-Delay (SE) (P4)

1: 4 Reps
2: 25 ±2500 mV 60 Hz

Rejection Range
3: 1 SE Channel
4: 1 Excite all reps w/Exchan 1
5: 10 Delay (units 0.01 sec)
6:2000 mV Excitation
7: 1 Loc [ Temp_C_1 ]
8: .001 Mult
9: 0 Offset

02: Polynomial (P55)

1: 4 Reps
2: 1 X Loc [ Temp_C_1 ]
3: 1 F(X) Loc [ Temp_C_1 ]
4: -53.784 C0
5: 147.97 C1
6: -218.76 C2
7: 219.05 C3
8: -111.34 C4
9: 23.365 C5

7.13 WATER LEVEL - GEOKON'S VIBRATING WIRE PRESSURE SENSOR

The vibrating wire sensor utilizes a change in
the frequency of a vibrating wire to sense
pressure. Figure 7.13-1 illustrates how an
increase in pressure on the diaphragm
decreases the tension on the wire attached to
the diaphragm. A decrease in the wire tension
decreases the resonant frequency in the same
way that loosening a guitar string decreases its
frequency.

Vibrating Wire Measurement Instruction 28
excites the "plucking" and "pickup" coils shown
in Figure 7.13-1 with a "swept" frequency. A
"swept" frequency is a group of different
frequencies that are sent one right after another
starting with the lowest frequency and ending
with the highest. The lowest and highest
frequencies are entered by the user in units of
hundreds of Hz. This swept frequency causes
the wire to vibrate at each of the individual
frequencies. Ideally, all of the frequencies
except the one matching the resonant
frequency of the wire will die out in a very short
time. The wire will vibrate with the resonant
frequency for a relatively long period of time,
cutting the lines of flux in the "plucking" and
"pickup" coils and inducing the same frequency
on the lines to the CR510. Instruction 28 then
accurately measures how much time it takes to
receive a user specified number of cycles.

The vibrating wire requires temperature
compensation. A nonlinear thermistor built into
the probe is measured using Instruction 4, a
single-ended half bridge measurement with
excitation, and calculated with Instruction 55, a
fifth order polynomial instruction.

Campbell Scientific's AVW1 Vibrating Wire
Sensor Interface is required between the sensor
to the datalogger. The purpose is twofold:

• 5 or 12 volts can be used as the potential in
the swept frequency excitation, thus
plucking the wire harder than the maximum

2.5 volt switched excitation. The result is a
larger magnitude signal for a longer time.

• A transformer strips off any DC noise on the
signal, improving the ability to detect cycles.

7-13

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

FIGURE 7.13-1. A Vibrating Wire Sensor

The following calculations are based on using a
Geokon model 4500 Vibrating Wire sensor. An
individual multiplier and offset must be
calculated for each sensor used in a system.

MULTIPLIER
The fundamental equation relating frequency to

pressure is

P = -F

G + B where

x

P = pressure, PSI
G = the Gage Factor obtained from the

sensors calibration sheet in PSI/digit.

2

The units of a digit are Hz

(10-3).

B = offset

=f2Hz2(10-3), where f is frequency.

F

x

Instruction 28 measures period, T, of the
vibrating wire in milliseconds (ms) and returns a
measured value, X, of

X = 1/(T

2

(ms)2) = f2(10-6)Hz

2

A multiplier of -1000 in Instruction 28 converts
the measurement to digits, as shown below.

= -X(-103) = -f2(10-3)Hz

-F

x

2

To calculate the multiplier, convert Geokon's
gage factor, G, to the desired units (i.e., feet of
water per digit) and multiply by -1000 digits/kHz

P

= P + C ∗ (t1 - t0), where

T

P

= Pressure corrected for temperature, °C

T

C = Temperature coefficient, PSI/°C

(from Geokon calibration sheet)

& t1= Initial and current temperatures, °C.

t

0

The temperature coefficient, C, must be
converted to units compatible with the gage
factor, G.

WELL MONITORING EXAMPLE
In this example the vibrating wire sensor is used

to monitor water table height (Figure 7.13-2).
The desired data is the distance from the lip of
the well to the water surface. The sensor is
vented to atmosphere to eliminate
measurement errors due to changes in
barometric pressure. The water level is
expected to stay within 40 to 80 feet of the lip so
the 50 psi pressure sensor is placed
approximately 100 feet below the lip of the well.
The calibration data from Geokon is provided in
Table 7.13-1.

TABLE 7.13-1 Calibration Data for

Sensor 3998

Gage Factor Temp. Coeff.

(psi/digit) (psi/°C)

2

.

0.0151 -0.0698

TEMPERATURE CORRECTION
The temperature correction is applied as

follows.

7-14

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

The multiplier, m, is calculated to convert the
reading to feet of water.

m = 0.0151 (psi/digit) ∗ 2.3067 (ft of water/psi) ∗

-1000 digits/kHz

2

= -34.831 ft of water/kHz

2

After the probe reaches thermal equilibrium, the
initial temperature, t

, is measured to be 24°C.

0

The water column above the sensor is referred
to as the "Reading". The Reading decreases
with increasing "Distance" from lip of well to
water surface so the Distance is computed by
subtracting the Reading from the Offset as
shown in Figure 7.13-2.

CR510 & AVW1

The "Initial Distance" to the water surface is
measured with a chalked line to be 47.23 feet
below the lip. The first time the program is
executed, the program calculates the offset
(Offset = Distance + Reading) required to obtain
a reading of 47.23 feet. The offset is stored in
Location 4 and applied to subsequent
measurements.

NOTE: Following program compilation in
the ∗0 Mode, all input locations are set to
zero. This fact is utilized to detect the first
execution following a program compilation.

The example assumes the sensor has been
connected as shown here.

FIGURE 7.13-2. Well Monitoring Example

7-15

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

CR510

Ch E1

12 V or 5 V

FIGURE 7.13-3. Hook up to AVW1

PROGRAM

AVW1 & CR510 USED TO MEASURE 1
GEOKON VIBRATING WIRE SENSOR.

* Table 1 Program

01: 60 Execution Interval (seconds)

01: Excite-Delay (SE) (P4)

1: 1 Reps
2: 15 ±2500 mV Fast Range
3: 1 SE Channel
4: 1 Excite all reps w/Exchan 1
5: 1 Delay (units 0.01 sec)
6:2500 mV Excitation
7: 1 Loc [ Temp ]
8: .001 Mult
9: 0 Offset

02: Polynomial (P55)

1: 1 Reps
2: 1 X Loc [ Temp ]
3: 1 F(X) Loc [ Temp ]
4: -104.78 C0
5: 378.11 C1
6: -611.59 C2
7: 544.27 C3
8: -240.91 C4
9: 43.089 C5

03: Vibrating Wire (SE) (P28)

1: 1 Reps
2: 2 SE Channel
3: 1 Excite all reps w/Exchan 1
4: 24 Starting Freq. (units = 100 Hz)
5: 32 End Freq. (units = 100 Hz)
6: 500 No. of Cycles
7: 0 Rep Delay (units = 0.01 sec)
8: 2 Loc [ Pressure ]
9: -34.836 Mult
10: 0 Offset

7-16

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

04: Z=X+F (P34)

1: 1 X Loc [ Temp ]
2: -24 F
3: 3 Z Loc [ Temp_Comp ]

05: Z=X*F (P37)

1: 3 X Loc [ Temp_Comp ]
2: -.0698 F
3: 3 Z Loc [ Temp_Comp ]

06: Z=X+Y (P33)

1: 3 X Loc [ Temp_Comp ]
2: 2 Y Loc [ Pressure ]
3: 2 Z Loc [ Pressure ]

07: IF (X<=>F) (P89)

1: 5 X Loc [ Cmpile_Ck ]
2: 1 =
3: 0 F
4: 30 Then Do

08: Z=X+F (P34)

1: 2 X Loc [ Pressure ]
2: 47.23 F
3: 4 Z Loc [ Offset ]

09: Z=F (P30)

1: 1 F
2: 0 Exponent of 10
3: 5 Z Loc [ Cmpile_Ck ]

(-40°C)] / [2000 mV - 400 mV] = 0.06875°C/mV.
The offset is found by taking the linear
relationship °C = mV ∗ Mult + Offset and solving
for the Offset. At -40°C the voltage is 400 mV,
thus the Offset = -40 - [400 mV ∗

0.06875°C/mV] = -67.5°C.

CONNECTIONS
The dew point sensor is measured with a
differential voltage measurement on differential
analog input 1. The CURS100 TIM and dew
point sensor are wired to the CR510 terminal
strip panel as shown in Figure 7.14-1.

PROGRAM

01: Volt (Diff) (P2)

1: 1 Reps
2: 25 ±2500 mV 60 Hz Rejection

Range
3: 1 DIFF Channel
4: 1 Loc [ Dew_Pnt_C ]
5: .06875 Mult
6: -67.5 Offset

INPUT LOCATIONS

1 Dew_Pnt_C

10: End (P95)
11: Z=X-Y (P35)

1: 4 X Loc [ Offset ]
2: 2 Y Loc [ Pressure ]
3: 6 Z Loc [ Distance ]

7.14 4 TO 20 MA SENSOR USING CURS100 TERMINAL INPUT MODULE

A dew point sensor has a 4 to 20 mA output
over the dew point temperature range of -40° to
+70°C. The dew point sensor output may be
measured by the CR510 using the CUS100
Terminal Input Module (TIM). The CUS100
uses a 100 Ω, ± 0.01 % resistor to convert the 4
to 20 mA range to 400 to 2000 mV. The
millivolt range was found using the relationship
V = IR, where V is voltage, I is current, and R is
resistance, e.g. the voltage at -40°C is given by
V = 4 mA ∗ 100 Ω = 400 mV. The dew point
sensor is measured with Instruction 2 (Volt Diff).
The multiplier for dew point temperature is
found with the following relationship [70°C -

7-17

SECTION 7. MEASUREMENT PROGRAMMING EXAMPLES

CR510

CR10X

H

4H

1H

1L

4L

AG

AG

100

0.01%

±

Ω

L

GND

CURS100

G

12V

G

4 to 20 mA

Sensor

FIGURE 7.14-1 Wiring Diagram for CURS100 Terminal Input Module and 4 to 20 mA Sensor.

7-18

SECTION 8. PROCESSING AND PROGRAM CONTROL EXAMPLES

The following examples are intended to illustrate the use of Processing and Program Control
Instructions, flags, dual Final Storage, and the capability to direct the results of Output Processing
Instructions to Input Storage.

The specific examples may not be as important as some of the techniques employed, for example:
Directing Output Processing to Input Storage is used in the Running Average and Rainfall Intensity

examples (8.1 and 8.2).
Flag tests are used in the Running Average, Interrupt Subroutine, Converting Wind Direction, and

Saving Data Prior to Event examples (8.1, 8.5, 8.7 and 8.8).
An algorithm for a down counter is used in the Saving Data Prior to Event example (8.8).

As in Section 7 these examples are not complete programs to be taken verbatim. They need to be
altered to fit specific needs.

8.1 COMPUTATION OF RUNNING AVERAGE

It is sometimes necessary to compute a running
average (i.e., the average covers a fixed
number of samples and is continuously updated
as new samples are taken). Because the
output interval is shorter than the averaging
period, Instruction 71 cannot be used; the
algorithm for computing this average must be
programmed by the user. The following
example demonstrates a program for
computing a running average.

In this example, each time a new measurement
is made (in this case the CR510 internal
temperature) an average is computed for the 10
most recent samples. This is done by saving all
10 temperatures in contiguous input locations
and using the Spatial Average Instruction (51)
to compute the average. The temperatures are
stored in locations 2 through 11. Each time the
table is executed, the new measurement is
stored in location 11 and the average is stored
in location 1. The Block Move Instruction (54) is
then used to move the temperatures from
locations 3 through 11 down by 1 location; the
oldest measurement (in location 3) is lost when
the temperature from location 4 is written over
it.

PROGRAM

* Table 1 Program

01: 10.0 Execution Interval (seconds)

01: Internal Temperature (P17)

1: 11 Loc [ Temp_i ]

02: Spatial Average (P51)

1: 10 Swath
2: 2 First Loc [ Temp_i_9 ]
3: 1 Avg Loc [ Av_10smpl ]

03: Block Move (P54)

1: 9 No. of Values
2: 3 First Source Loc [ Temp_i_8 ]
3: 1 Source Step
4: 2 First Destination Loc [ Temp_i_9 ]
5: 1 Destination Step

04: Do (P86)

1: 10 Set Output Flag High

05: Sample (P70)

1: 1 Reps
2: 1 Loc [ Av_10smpl ]

INPUT LOCATIONS

1 Av_10smpl 7 Temp_i_4
2 Temp_i_#9 8 Temp_i_3
3 Temp_i_8 9 Temp_i_2
4 Temp_i_7 10 Temp_i_1
5 Temp_i_6 11 Temp_i
6 Temp_i_5

8-1

SECTION 8. PROCESSING AND PROGRAM CONTROL EXAMPLES

In the above example, all samples for the
average are stored in input locations. This is
necessary when an average must be output
with each new sample. In most cases,
averages are desired less frequently than
sampling. For example, it may be necessary to
sample some parameter every 5 seconds and
output every hour an average of the previous
three hours' readings. If all samples were
saved, this would require 2160 input locations.
The same value can be obtained by computing
an hourly average and averaging the hourly
averages for the past three hours. To do this
requires that hourly averages be stored in input
locations.

Instruction 80 is used to send the 1 hour
average to Input Storage and again to send the
3 hour average to Final Storage.

PROGRAM

* Table 1 Program

01: 5.0 Execution Interval (seconds)

01: Volt (Diff) (P2)

1: 1 Reps
2: 25 ±2500 mV 60 Hz

Rejection Range
3: 1 DIFF Channel
4: 5 Loc [ XX_mg_M3 ]
5: 10 Mult
6: 0 Offset

02: If time is (P92)

1: 0 Minutes (Seconds --) into a
2: 60 Interval (same units as

above)
3: 10 Set Output Flag High

03: Set Active Storage Area (P80)

1: 3 Input Storage Area
2: 3 Array ID or Loc [ avg_i ]

07: Real Time (P77)

1: 0110 Day,Hour/Minute

08: Sample (P70)

1: 1 Reps
2: 4 Loc [ 3_Hr_avg ]

09: If Flag/Port (P91)

1: 10 Do if Output Flag is High

(Flag 0)

2: 30 Then Do

10: Block Move (P54)

1: 2 No. of Values
2: 2 First Source Loc

[ avg_i_1 ]
3: 1 Source Step
4: 1 First Destination Loc

[ avg_i_2 ]
5: 1 Destination Step

11: End (P95)

INPUT LOCATIONS

1 avg_i_2
2 avg_i_1
3 avg_i
4 3_Hr_avg
5 XX_mg_M3

8.2 RAINFALL INTENSITY

In this example, the total rain for the last 15
minutes is output only if any rain has occurred.
The program makes use of the capability to
direct the output of Output Processing
Instructions to Input Storage.

Every 15 minutes, the total rain is sent to Input
Storage. If the total is not equal to 0, output is
redirected to Final Storage Area 1, the time is
output and the total is sampled.

04: Average (P71)

1: 1 Reps
2: 5 Loc [ XX_mg_M3 ]

05: Spatial Average (P51)

1: 3 Swath
2: 1 First Loc [ avg_i_2 ]
3: 4 Avg Loc [ 3_Hr_avg ]

06: Set Active Storage Area (P80)

1: 1 Final Storage Area 1
2: 25 Array ID or Loc [ _________ ]

8-2

PROGRAM

* Table 1 Program

01: 60.0 Execution Interval (seconds)

01: Pulse (P3)

1: 1 Reps
2: 1 Pulse Input Channel
3: 2 Switch Closure
4: 1 Loc [ Precip_mm ]
5: .254 Mult
6: 0 Offset

SECTION 8. PROCESSING AND PROGRAM CONTROL EXAMPLES

02: If time is (P92)

1: 0 Minutes (Seconds --) into a
2: 15 Interval (same units as above)
3: 10 Set Output Flag High

03: Set Active Storage Area (P80)

1: 3 Input Storage Area
2: 2 Array ID or Loc [ 15min_tot ]

In this example a temperature (107
Temperature Probe) is measured every 0.5
seconds and the average output every 30
seconds.

PROGRAM

* Table 1 Program

01: 0.5 Execution Interval (seconds)

04: Totalize (P72)

1: 1 Reps
2: 1 Loc [ Precip_mm ]

05: IF (X<=>F) (P89)

1: 2 X Loc [ 15min_tot ]
2: 2 <>
3: 0 F
4: 30 Then Do

06: Set Active Storage Area (P80)

1: 1 Final Storage Area 1
2: 25 Array ID or Loc

[ _________ ]

07: Real Time (P77)

1: 0110 Day,Hour/Minute

08: Sample (P70)

1: 1 Reps
2: 2 Loc [ 15min_tot ]

09: End (P95)

INPUT LOCATIONS

1 Precip_mm
2 15min_tot

8.3 SUB 1 MINUTE OUTPUT INTERVAL SYNCHED TO REAL TIME

Output can be synchronized to seconds by
pressing “-” or “C” whi le entering the first
parameter in Instruction 92. If a counter,
incremented within the program, was used to
determine when to set the Output Flag, output
would depend on the number of times the table
was executed. The actual time of output would
depend on when the program was actually
compiled and started running. If the table
overran its execution interval (Section 1.1.1),
the output interval would not be the count
multiplied by the execution interval, but some
longer interval.

01: Temp (107) (P11)

1: 1 Reps
2: 1 SE Channel
3: 1 Excite all reps w/E1
4: 1 Loc [ Temp ]
5: 1.0 Mult
6: 0.0 Offset

02: If time is (P92)

1: 0-- Minutes (Seconds --) into a
2: 30 Interval (same units as above)
3: 10 Set Output Flag High

03: Average (P71)

1: 1 Reps
2: 2 Loc [ TC_Temp ]

INPUT LOCATIONS

1 Ref_Temp
2 TC_Temp

8.4 SWITCH CLOSURES ON CONTROL PORTS (RAIN GAGE)

Control port 2 can be used to measure switch
closures up to 40 Hz. Instruction 3, pulse, is
used to measure two rain gages on pulse input
1, and a rain gage with control port 2. This is
done as a comparison. In a real application the
pulse channel would be used for wind speed
and a control port for a rain gage. The rain
gage is connected as diagrammed below.

CR510

+5

C2/P3

FIGURE 8.4-1. Connections for Rain Gage

8-3

SECTION 8. PROCESSING AND PROGRAM CONTROL EXAMPLES

PROGRAM

* Table 1 Program

01: 10.0 Execution Interval (seconds)

01: Pulse (P3)

1: 1 Reps
2: 1 Pulse Input Channel
3: 2 Switch Closure
4: 10 Loc [ Precip_1 ]
5: .254 Mult
6: 0 Offset

02: Pulse (P3)

1: 1 Reps
2: 3 Pulse Channel 3
3: 2 Switch Closure
4: 11 Loc [ Precip_2 ]
5: .254 Mult
6: 0 Offset

03: If time is (P92)

1: 0 Minutes (Seconds --) into a
2: 60 Interval (same units as above)
3: 10 Set Output Flag High

04: Real Time (P77)

1: 0110 Day,Hour/Minute

05: Totalize (P72)

1: 2 Reps
2: 10 Loc [ Precip_1 ]

INPUT LOCATIONS

10 Precip_1
11 Precip_2

8.5 CONVERTING 0-360 WIND DIRECTION OUTPUT TO 0-540 FOR STRIP CHART

If 0-360 degree wind direction is output to a strip
chart the discontinuity at 0/360 will cause the pen
to jump back and forth full scale when the winds
are varying from the north. In the days of strip
charts this was solved with a 0-540 degree pot on
the wind vane (direction changes from 540 to 180
and from 0 to 360 so the pen only jumps once
when the wind is out of the north or south).

When faced with the necessity of strip chart
output, the following algorithm can be used to
change a 0-360 degree input to 0-540. (If you
have a 0-540 pot, it can be used with the
CR510 since the Wind Vector Instruction, 69,
will work with this output.)

To change 0-360 degrees to the 0-540 degrees,
360 degrees must sometimes be added to the
reading when it is in the range of 0 to 180. The
following algorithm does this by assuming that if
the previous reading was less than 270, the vane
has shifted through 180 degrees and does not
need to be altered. If the previous 0-540 reading
was greater than 270, 360 degrees is added.

This example is written as a subroutine which is
used to output an analog voltage to a strip
chart.

* Table 3 Subroutines
01: Beginning of Subroutine (P85)

1: 1 Subroutine 1

02: IF (X<=>F) (P89)

1: 10 X Loc [ 0_540_WD ]
2: 3 >=
3: 270 F
4: 30 Then Do

03: Do (P86)

1: 11 Set Flag 1 High
04: Else (P94)
05: Do (P86)

1: 21 Set Flag 1 Low
06: End (P95)
07: Z=X (P31)

1: 2 X Loc [ 0_360_WD ]

2: 10 Z Loc [ 0_540_WD ]
08: IF (X<=>F) (P89)

1: 10 X Loc [ 0_540_WD ]

2: 4 <

3: 180 F

4: 30 Then Do
09: If Flag/Port (P91)

1: 11 Do if Flag 1 is High

2: 30 Then Do
10: Z=X+F (P34)

1: 10 X Loc [ 0_540_WD ]

2: 360 F

3: 10 Z Loc [ 0_540_WD ]
11: Z=X (P31)

1: 10 X Loc [ 0_540_WD ]

2: 6 Z Loc [ 0_540_out ]

8-4