Campbell Scientific RF300 User Manual

Radiotelemetry Network

Revision: 3/00

Copyright © 1989-2000

Campbell Scientific, Inc.

Warranty and Assistance

The RADIOTELEMETRY NETWORK COMPONENTS are warranted by
CAMPBELL SCIENTIFIC, INC. to be free from defects in materials and
workmanship under normal use and service for twelve (12) 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. The following
contact information is for US and International customers residing in countries
served by Campbell Scientific, Inc. directly. Affiliate companies handle
repairs for customers within their territories. Please visit
www.campbellsci.com to determine which Campbell Scientific company
serves your country. 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

CAMPBELL SCIENTIFIC, INC. does not accept collect calls.

RADIOTELEMETRY NETWORK

TABLE OF CONTENTS

PDF viewers note: These page numbers refer to the printed version of this document. Use
the Adobe Acrobat® bookmarks tab for links to specific sections.

PAGE

1. GENERAL RADIOTELEMETRY NETWORK

1.1 Introduction.............................................................................................................................1-1

1.2 Field Station ........................................................................................................................... 1-2

1.3 Base Station...........................................................................................................................1-3

1.4 Repeater.................................................................................................................................1-4

2. ASSEMBLING THE RADIOTELEMETRY NETWORK

2.1 Final Layout............................................................................................................................2-1

2.2 Install Base Station.................................................................................................................2-1

2.2.1 Base Station Hardware..........................................................................................................2-1

2.2.2 PC208W Datalogger Support Software.................................................................................2-1

2.3 Install Nearest Repeater/Field Station...................................................................................2-5

2.4 Test the Radiotelemetry Link ................................................................................................. 2-5

2.4.1 A Successful Test ..................................................................................................................2-5

2.4.2 An Unsuccessful Test ............................................................................................................2-5

2.5 Troubleshooting Unsuccessful Communication Attempts ..................................................... 2-5

2.5.1 Troubleshooting Physical Link Between Base and Field Station........................................... 2-5

2.5.2 Error Messages......................................................................................................................2-6

2.5.3 Troubleshooting with the Terminal Emulator ......................................................................... 2-6

3. RADIOTELEMETRY NETWORK COMPONENTS

3.1 RF95A Modem.......................................................................................................................3-1

3.1.1 Physical Description...............................................................................................................3-1

3.1.2 RF95A States......................................................................................................................... 3-1

3.1.3 Setting Station ID ................................................................................................................... 3-2

3.1.4 The Carrier Detect Light.........................................................................................................3-2

3.1.5 Data Transfer Rate.................................................................................................................3-2

3.1.6 RF95A Modem Communication Protocol...............................................................................3-3

3.1.7 RF95A Modem and the RF Link.............................................................................................3-3

3.1.8 RF95A Connections...............................................................................................................3-5

3.2 RF300 Radios ........................................................................................................................3-6

3.2.1 Radio Description...................................................................................................................3-6

3.2.2 Radio Specifications............................................................................................................... 3-6

3.2.3 Radio Installation.................................................................................................................... 3-7

3.3 Antennas and Cables.............................................................................................................3-7

3.3.1 Antenna Mounts.....................................................................................................................3-7

3.3.2 Antenna Orientation...............................................................................................................3-7

3.3.3 Antenna Cables and Connectors...........................................................................................3-7

3.4 Tripods, Towers, Enclosures, and Power Supplies...............................................................3-9

3.4.1 Tripods and Towers for Mounting..........................................................................................3-9

3.4.2 Enclosures..............................................................................................................................3-9

3.4.3 Power Supply.........................................................................................................................3-9

3.5 RF232A Base Station...........................................................................................................3-10

3.5.1 RF232A Introduction............................................................................................................3-10

3.5.2 220, 230, and 240 VAC Conversion ....................................................................................3-11

i

RF MANUAL TABLE OF CONTENTS

4. OPERATION OF THE RADIOTELEMETRY NETWORK

4.1 Monitoring and Collecting Data - PC208W RF Notes............................................................4-1

4.1.1 Basic Concepts ......................................................................................................................4-1

4.1.2 Using PC208W Setup Window .............................................................................................. 4-1

4.1.3 Automated Data Collection - PC208W...................................................................................4-2

4.1.4 General Communication - PC208W Connect Window..........................................................4-3

4.2 Datalogger Initiated Communications....................................................................................4-4

APPENDIX A. SETTING THE STATION ID........................................................................A-1

APPENDIX B. ALTERNATE BASE STATION CONFIGURATIONS

B.1 The Portable Base Station.........................................................................................................B-1

B.2 Phone-to-RF Base Station ........................................................................................................B-1

B.3 Phone-to-RF Base Station with Measurement Capability.........................................................B-2

APPENDIX C. POWER CALCULATIONS...........................................................................C-1

APPENDIX D. FUNDAMENTALS OF RADIOTELEMETRY

D.1 Radio Waves..........................................................................................................................D-1

D.2 Antennas................................................................................................................................D-1

D.3 RF95A Modem.......................................................................................................................D-2

D.4 Transceiver.............................................................................................................................D-2

APPENDIX E. RF95A STATES

E.1 RF95A-ME States ..................................................................................................................E-1

E.2 RF95A-SDC State..................................................................................................................E-1

APPENDIX F. EQUIPMENT COMPATIBILITY

F.1 Compatibility of Current and Past RF Equipment..................................................................F-1

F.2 The "U" Command .................................................................................................................F-1

F.3 Incorporating the RF300 and the RF95A...............................................................................F-2

APPENDIX G. P50 RADIO

G.1 P50 Radio Setup and Specifications..................................................................................... G-1

G.1.1 Volume Control...................................................................................................................... G-1

G.1.2 Squelch Control..................................................................................................................... G-1

G.1.3 Frequency Switch.................................................................................................................. G-1

G.1.4 P50 Specifications................................................................................................................. G-1

G.2 Additional Troubleshooting for P50 Radios........................................................................... G-1

G.3 Troubleshooting with Attenuation Pads ................................................................................ G-2

APPENDIX H. RF300 RADIO SPECIFICATIONS.............................................................H-1

APPENDIX I. RF100/200 RADIOS

I.1 Radio Description.................................................................................................................... I-1

I.2 Radio Specifications................................................................................................................ I-1

ii

RF MANUAL TABLE OF CONTENTS

APPENDIX J. CABLE PIN OUTS AND LED FUNCTION

FOR RF95A AND RF300...............................................................................................H-1

GLOSSARY................................................................................................................a

LIST OF FIGURES

1-1 A Basic Radiotelemetry Network ........................................................................................... 1-1

1-2 A CR10(X) Field Station.........................................................................................................1-2

1-3 An RF Telemetry Base Station...............................................................................................1-3

1-4 A Typical RF Telemetry Repeater Station.............................................................................1-4

3-1 The RF95A Modem................................................................................................................3-1

3-2 Setting the Station ID.............................................................................................................3-2

3-3 RF300 On Bracket With Connector.......................................................................................3-6

3-4 The PD237 Crossover Plate Antenna Mount.........................................................................3-7

3-5 The PD46 Clamp Mount.........................................................................................................3-8

3-6 Type-NM (male), BNC, and Type-NF (female) Connectors...................................................3-8

3-7 The RF232A Base Station...................................................................................................3-11

3-8 Top View of the RF232A Base Station................................................................................3-12

4.1-1 PC208W Main Tool Bar .........................................................................................................4-1

4.1-2 PC208W Setup Window/Schedule Tab.................................................................................4-2

4.1-3 PC208W Connect Window, Tools Tab .................................................................................. 4-3

B-1 Portable Base Station ............................................................................................................B-2

B-2 Phone-to-RF Base Station.....................................................................................................B-3

B-3 Phone-to-RF Base with Measurement Capability..................................................................B-3

G-1 P50 Radio Settings ............................................................................................................... G-1

I-1 RF100 On Bracket With Connector ........................................................................................I-1

LIST OF TABLES

3-1 A Sample of Station ID Numbers and the Corresponding Switch Settings...........................3-2

3-2 RF95A Command Character Summary.................................................................................3-4

3-3 Summary of the Shutdown Block...........................................................................................3-5

3-4 RF95/A Serial I/O to Datalogger Connector Description.......................................................3-6

3-7 Common Antennas and Characteristics................................................................................3-8

3-8 PS12LA Battery and AC Transformer Specifications..........................................................3-10

3-9 Pin Description for RF232A's 25-Pin Port............................................................................3-11

3-10 RF232A Power Conversions................................................................................................ 3-11

F-1 Different RF Setups................................................................................................................F-1

F-2 Radio Frequency Range........................................................................................................F-2

H-1 RF300 Radio Specifications - UHF........................................................................................H-1

H-2 RF300 Radio Specifications - VHF........................................................................................H-2

H-3 RF300 Radio Specifications - Loader Board .........................................................................H-4

I-1 Radio to RF Modem Pin Descriptions..................................................................................... I-1

I-2 RF100/RF200 Radio Specifications........................................................................................I-2

J-1 Radio 10 Pin RF Connector...................................................................................................J-1

J-2 RF95A 10 Pin RF Connector ................................................................................................. J-1

J-3 Radio to RF95A Cable Pin Outs ............................................................................................ J-1

J-4 Radio 9 Pin Serial Communications Connectors................................................................... J-2

J-5 JDT Software.......................................................................................................................... J-2

iii

RF MANUAL TABLE OF CONTENTS

LIST OF EXAMPLES

3-1 A Sample Setup Block............................................................................................................3-4

3-2 Sample Shutdown Block........................................................................................................3-5

F-1 Use of the "U" Command.......................................................................................................F-1

iv

SECTION 1. GENERAL RADIOTELEMETRY NETWORK

1.1 INTRODUCTION

Data retrieval from a remote site can be difficult.
To accomplish data collection from isolated
sites Campbell Scientific, Inc. utilizes a
radiotelemetry (RF telemetry) network.
Dataloggers can be accessed by RF telemetry
which requires no physical connection from the
computer to the datalogger. The RF telemetry
link reduces the number of visits to a remote
site for data collection.

The RF telemetry network is designed for
complete computer control. One computer can
establish communication with up to 254 remote
sites. PC208W Datalogger Support Software
allows data collection from the datalogger,
transmitting datalogger programs, and
displaying current readings from the datalogger.

The requirements specific to a RF telemetry
network include:

• The distance between radio stations should
not be greater than approximately 25 miles.

• The stations should not have major
obstacles between them; therefore, they
should be within line-of-sight of each other.

The stations communicate over a radio
frequency which is specified in Megahertz
(MHz, 132 to 170 MHz and 403 to 512 MHz are
supported). A data communication network
must have its own specific frequency to prevent
interference from other sources. Typical radio
frequencies are either VHF (Very High
Frequency) ranging from 132 to 170 MHz or
UHF (Ultra High Frequency) ranging from 403
to 512 MHz. A typical RF system is shown in
Figure 1-1.

Telemetry network’s three basic components
are:

• Field Station

• Base Station

• Repeater Station

FIGURE 1-1. A Basic RF telemetry Network

1-1

SECTION 1. GENERAL RADIOTELEMETRY NETWORK

1.2 FIELD STATION

Purpose: The field station is where the

measurements are made. The
Campbell Scientific datalogger
resides at this station taking the
desired measurements. Any field
station can also operate as a
repeater. The only requirement is
that the station’s antenna must be
able to communicate in all desired
directions. This may require an
omnidirectional antenna.

Equipment Required:

• Radio

• RF Modem

• Antenna and antenna cable

• Datalogger

• Power supply, enclosure,

sensors, and mounting needs

ANTENNA

CR10X

RF95A

FIGURE 1-2. A CR10(X) Field Station

1-2

SECTION 1. GENERAL RADIOTELEMETRY NETWORK

1.3 BASE STATION

Purpose: A base station utilizes a computer

to collect data from the field
station(s). Normally, all
communication to the field stations
originate at the base station. Data
retrieval, remote programming, and
system analysis can all be done
from the base station.

Equipment Required:

• Radio

• RF Base Station

• Computer with PC208W

software

• Antenna and antenna cable

• AC power

RS232 Cable

To Antenna

PC208W

Datalogger Support Software for Windows

Setup Instructions: Disk 1 of 4

1. Start Microsoft Windows

2. Insert Disk 1 in drive A.

3. From Program Manager, select File menu and
choose Run

4. Type a:\setup and press ENTER.

815 W. 1800 N. Logan Utah 84321-1784 [phone] FAX [phone]

Copyright(c) 1996

FIGURE 1-3. An RF Telemetry Base Station

POWER
ON

RF232A

RF BASE STATION

CARRIER DETECT

MADE IN U.S.A.

1-3

SECTION 1. GENERAL RADIOTELEMETRY NETWORK

1.4 REPEATER

Purpose: To act as relay between two

communicating stations separated
by too long of a distance or an
obstacle which impedes direct
communication. A repeater is not
always required in a RF telemetry
network. A field station can also
function as a repeater.

Equipment Required:

• Radio

• RF Modem

• Antenna and antenna cable

• 12V and 5V power supply

(PS512M or CH512R and
BP12)

• Enclosure and other mounting

needs

PS512M

RF95A

RF300

FIGURE 1-4. A Typical RF Telemetry Repeater Station

1-4

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

This section provides a logical order for RF network assembly and deployment. Details of specific
components in the system are described in Section 3 “Radiotelemetry Network Components.” Section 3
is cross-referenced throughout this assembly section.

2.1 FINAL LAYOUT

The initial locations of the base, field, and
repeater stations have likely been determined
already. Locate RF stations on an area map,
preferably a topographic map. Draw a line
along every communication path. Each field
station must have a path connecting it back to
the base station. No path can be going through
a mountain or large obstacle; this would negate
the line-of-sight requirement. A station may
need to be moved or a repeater station may
need to be added if this requirement is not met.

At each station there is an RF modem. Each
modem requires a unique ID number (Station
ID). The number may range from 0 to 255. On
the map, label the base station as 254. Label
the remaining stations with different ID
numbers. Later, each modem will be set with
the corresponding ID number. The Station ID,
similar to a phone number, allows the base
station to call many different field stations.

2.2 INSTALL BASE STATION

2.2.1 BASE STATION HARDWARE

The major component of the base station is the
RF232A Base Station. Refer to Section 3.5 for
location drawings and a description of the
RF232A Base Station.

1. Remove the top of the RF232A by
unscrewing the four screws on the sides.

2. Remove the radio and its cable from its
mounting bracket. Mount the radio directly
onto the bottom of the RF232A. Secure the
BNC connector from the radio's cable to its
hole on the back of the RF232A. See
Figure 3-7 for assistance.

3. Connect the radio to 12 V, ground, and the
RF Modem (RF95A). The RF modem is
located behind the front panel above the
"POWER ON" light. See Figure 3-8 for
assistance.

CAUTION: Radio transmission without an
antenna connected can damage radio.

4. Mount the base station antenna in a
location that is higher than any surrounding
buildings or obstacles. Refer to Section 3.3
for more information on mounting the
antenna.

5. After the antenna is mounted, connect the
coax cable between the antenna and the
BNC connector mounted in Step 2.

6. Replace the cover of the RF232A.

7. Connect a large gauge (approximately 8
AWG) copper wire from the antenna to a
good earth ground. This is for lightning
protection. This is required for any
antenna, especially if the coax cable from
the antenna goes inside a building.

8. Connect a 25-pin RS232 cable from the
computer serial port to the RF232A.

9. After verifying that the RF232A power
switch is off, plug in the RF232A's wall
transformer.

2.2.2 PC208W DATALOGGER SUPPORT SOFTWARE

Once the base station hardware is installed, the
PC208W software must be setup. If PC208W
is not installed on the computer, you will need to
install it. Refer to the PC208W Manual if you
have questions about the installation procedure
or PC208W.

There are eight main windows in PC208W:

• SETUP - Used to define communication

paths, set data collection parameters, and
schedule automatic data collection.

• CONNECT - Used for manual

communications with field site. Supports
real time data display, graphs, data retrieval
and program transfer.

• STATUS - Shows status of schedules and

communication information.

• PROGRAM - Editor to aid writing datalogger

programs.

2-1

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

• REPORT - Generates reports and reduces
data stored on computer.

• VIEW - Used to view text files.

• STG MODULE - Used to service storage

modules, SM192 or SM716.

• HELP - On line help. Also accessed
anywhere by typing F1.

PC208W uses a main tool bar to access each
of the eight windows. The shape of the main
tool bar can be changed using standard
Windows methods. Closing the main tool bar
closes all other PC208W windows.

The SETUP window is used to create a device
map which contains the RF Link information.
This information includes the station ID,
communication path and conditions for calling a
particular field station. Procedures for creating an
RF communications link are explained in section
1 of the PC208W manual.

Basic steps required to setup an RF link include:

1) select appropriate communications port (COM
Port), 2) attach RF modem to COM port, and 3)
attach datalogger to RF modem. The default COM
port settings should not be changed. The RF
modem default settings will work for current
hardware. Use the hardware tab to select 1200
baud for RF systems using the DC95. The default
datalogger settings do not need changing except for
the “Dialed using RF 95 path:”.

The RF Path (Dialed Using RF 95 Path:), found on
the datalogger hardware tab of the setup screen,
designates which field station to call. In the
example shown, the base station will call the field
station with an RF path of 10. If a repeater is
needed to contact Field Station 10, the repeater ID
must also be specified. For example, "RF Path: 5
10F," would call Field Station 10 through a repeater
with a Station ID of 5. The "F" at the end of the RF
Path is optional and is explained later. Click on
Save Edits.

2-2

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

Select the Appropriate Communications port. If your computer uses COM2, click the “Add COM port”
button to add an RS232 communications port. Next click the “Add Device” button.

When the “Add Device” button is clicked the “Add New Device” dialog box opens. Select the RF Modem
and attach to the appropriate RS232 communications port. Click OK.

2-3

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

This window shows the RF modem (RF1) attached to RS232 communication port 2. Next use the Add
Device button again to connect the datalogger to RF1.

This window shows the CR10X datalogger connected to the RF modem. Notice the Dialed Using RF95
path has been set to 10F. The RF95A path is unique to the RF95A dip switch settings.

2-4

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

2.3 INSTALL NEAREST REPEATER/

FIELD STATION

Now to install the nearest field station. If it
communicates with the base station via a
repeater, the repeater station must also be
installed.

Following is the order in which a general RF
field station should be installed. A repeater
station is installed in the same order. For
instructions on installing any particular
component, refer to either Section 3 of this
manual or the Weather Station Manual.

1. Tripod or tower

2. Enclosure and datalogger

3. Antenna - Orient correctly; remember
direction and polarization

4. Solar Panel

5. Power Supply

6. Sensors

7. RF Modem - Set the Station ID according to
the map

8. Radio - Make sure to connect to RF
Modem, to power supply, and turn on power
supply

2.4 TEST THE RADIOTELEMETRY LINK

With the field station installed, return to the
base station for initial testing of the
communication link. An RF link can also be
tested at the field site with a portable base
station; hardware requirements for the portable
base station are described in Appendix B.

2.4.1 A SUCCESSFUL TEST

The test is considered successful if you
establish communications between the PC and
the datalogger.

2.4.2 AN UNSUCCESSFUL TEST

When an RF test is unsuccessful, there are
three ways to troubleshoot the system:

1. Verify everything is connected properly.
See Section 2.5.1 for more suggestions.

2. Use the error messages in the error file to
identify where the link is breaking down.
See Section 2.5.2 for more information.

3. Try communicating from the base station to
the field station, one step at a time. Identify
where communications failed. See Section

2.5.3 for more information.

2.5 TROUBLESHOOTING UNSUCCESS­FUL COMMUNICATION ATTEMPTS

2.5.1 TROUBLESHOOTING PHYSICAL LINK BETWEEN BASE AND FIELD STATION

When communication is not established,
troubleshooting begins with the simplest RF link
in the system, which is usually communication
with the nearest field station. There is NO
substitute for first checking the hardware
connections, Station IDs, and everything listed
in the previous section. Below are a few
additional items to check:

1. Antenna is used in proximity of metal.

2. Transmitting inside a building.

Testing begins with turning the RF232A base
station on. A quick check of connections is in
order. Start PC208W software and open the
Connect Window. The “Station List” will show
all dataloggers or field stations available. Using
the mouse, highlight the datalogger of interest
then click on the Connect button. The software
requires about 15 seconds to establish a PC to
datalogger RF link. The computer is “talking”
with the datalogger when the first button to the
right of the Connect button changes from
Terminate to Disconnect.

If you do not click on the Disconnect or
Terminate button before closing the Connect
window, PC208W will automatically start calling
the datalogger when the Connect window is
reopened.

3. Damaged or shorted cables.

4. Bad or improper connections.

5. Antenna frequency does not match the

radio frequency.

6. Base and field station radios aren't using

same frequency.

7. Datalogger power drops below 9.6 Volts

during RF transmission. Use datalogger
Instruction 10 or volt meter to measure
battery voltage.

If the field station's RF95A Modem's Carrier
Detect light goes on, then at least a signal is
reaching the site. If this occurs, check the
following:

2-5

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

1. RF modem's ID matches ID in the RF Path.

2. Field station's radio and datalogger have
sufficient power.

3. Radio is connected to RF modem.

4. RF modem is the only thing connected to
datalogger's 9-pin connector.

2.5.2 ERROR MESSAGES

PC208W will log all activity related to each
Communications port (COM port). There are
two ways to view the messages. On the
PC208W main tool bar, click the Status button.
The lower right part of the Status window has a
button labeled “View Messages”. Click the View
Messages button. The message window lists
all events. The Status window has a check box
to allow these messages to be logged to disk.
The log file is a text file.

One possible error message is "RF1 Failed to
Get Attention." This message indicates
PC208W cannot communicate with the RF95A
modem. Check the following items:

4. Are Station IDs set properly in the RF
Modems?

5. Is the RF Path in the Setup Window
correct?

6. Are the antennas oriented correctly?

7. Check all antenna cable connections.

8. Turn radio off. Unplug the SC12 9-pin
ribbon cable from the RF95A in the
RF232A, reconnect the SC12 cable and
watch the carrier detect light. Does the light
stay on for one second, off for one second,
on for one second, and then off? If not, the
RF95A could have bad RAM or ROM. Also
check the field/repeater station modems.

9. Is the field station datalogger turned on and
does it have sufficient power?

VERIFY NEXT ERROR MESSAGE

The error message "RF Modem Does Not
Respond" can occur if communication is not
returned to the base station. Check the
following items:

1. RF232A Base Station plugged into
computer and wall outlet?

2. RF232A Power Switch turned on?

3. Has PC208W been set up correctly?

4. Is the proper COM port specified in the
Setup window?

5. Is the SC12 9-pin ribbon cable inside the
RF232A connected from the small circuit
board to the RF95A Modem?

6. Is there other software open that uses a
COM port?

Another possible error message is "CR10X_1
Failed to Connect" (where “CR10X_1” is the
station name). If this message is given without
the previous message, "RF1 Failed to Get
Attention", PC208W did connect with the RF
modem but not the datalogger. In this case,
check the following items:

1. Are the radios plugged in to the RF
modems?

2. Are the radios connected to power?

3. Verify that nothing but an RF modem is
connected to the datalogger's 9-pin
connector.

1. Are all RF Modems connected to radios and
dataloggers?

2. Are the antennas oriented properly?

3. Is the SDC switch open?

4. Is the proper COM port being specified?

2.5.3 TROUBLESHOOTING WITH THE TERMINAL EMULATOR

A general understanding of the communication
sequences is necessary to properly trouble­shoot an RF link. The base station RF modem
(RF95A) is called the Start Of Link modem, or
SOL modem. The field station RF modem is
called the End Of Link modem, or EOL modem.
When powered up, the SOL modem
immediately goes into a Wait Mode. The
RF95A Modem has five different modes of
operation; these are described in Section 3 of
this manual.

PC208W, Connect window has three tabs:
Tools, Numeric Display and Terminal Emulator.
With the Tools tab active, select the datalogger
of interest in the “Station List”. Select the
“Terminal Emulator” tab. Once in the Terminal
Emulator window, select “Open Port”. Terminal
Emulator allows you to send individual
commands to each device in the

2-6

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

communication path. This will allow you to test
each piece of the communication path
separately.

Try the following TASKs in order.
TASK A, Contact RF232A: Press [ENTER] a

few times, to set the baud rate between the
Base Station's RF modem and the computer.
This baud rate can be set at 300, 1200, or 9600
baud. The RF95A will detect the computer’s
baud rate and match it.

RESPONSE IF SUCCESSFUL: "!" prompt
given, SOL modem is now in the Local
Command Mode. This is where PC208W is
communicating with the RF232A base station.

If TASK A is unsuccessful, check:

1. Communication port (COM port) could be
configured improperly, computer setup.

2. The wrong COM port may be specified in
the Station File, PC208W setup.

3. Communication cable may be connected to
the wrong port. Use the correct serial port,
not the parallel port.

4. Computer mouse driver could be interfering
with COM port.

5. The base station or radio may not be
powered sufficiently.

6. The radio and RF modem may not be
connected properly.

7. Communications cable between computer
and RF232A must be standard RS232
cable.

TASK B: Task A must be successful before
Task B can be tested. To test the RF link; enter
the 'RF Path' at the “!” prompt. For example,
"S5 8F" communicates to a field station with a
Station ID of 8 through a repeater with an ID of

5. After typing the 'RF Path', press [ENTER].

RESPONSE IF SUCCESSFUL: "$" prompt
given. The dollar sign prompt is returned by the
EOL modem. The “$” indicates you are now
communicating with the modem at the field site.

Things to check if TASK B is unsuccessful:

1. Improper antenna orientation.

2. Bad connections on the antenna cables, or
improper antenna cables.

3. Insufficient current supply at the base
station. Is AC power good?

4. Field station radio is not connected to power
or power supply is weak. Check battery
voltage under load, should be no less than

11.7 volts. Battery voltage no load and no
charging source should be about 12.4 volts.

5. Field station radio and RF modem may not
be connected properly. Check cable.

6. Field station RF modem is not receiving 5
Volts from datalogger connection on pin 1
of the 9-pin cable. The RF modem must be
connected to the datalogger Serial I/O or
CS /IO port with a straight through cable,
SC12.

7. Using wrong RF path. Are the RF95A dip
switches set correctly?

TASK C: Establish link and baud rate between
RF Modem and Datalogger by slowly pressing
[ENTER] a few times. Pause about 2 seconds
between each press of the enter key.

RESPONSE IF SUCCESSFUL: "*" from
datalogger. The Asterisk prompt indicates the
datalogger is now communicating with the
computer at the base station.

Things to check if TASK C is unsuccessful:

1. Datalogger is on and has sufficient power.

2. Datalogger does not think it is still
communicating with some other device like
a CR10KD keypad or phone modem.

3. Datalogger and RF Modem are the only
devices connected together on the 9-pin
connections.

Upon successful completion of TASK C, the
datalogger is now in standard Telecom­munications Mode. See Section 5 of the
datalogger manual for more information about
the Telecommunication mode. At this point the
SOL modem and EOL modem will be in the
Transparent Mode of operation. Type "A," wait
2 seconds, and then type [ENTER] to receive a
status sequence from the datalogger. If
everything is successful, type “E” to drop the
link. If task C is successful, PC208W should be
able to call the field site.

2-7

SECTION 2. ASSEMBLING THE RADIOTELEMETRY NETWORK

This is a blank page.

2-8

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

3.1 RF95A MODEM

The RF95A is an interface between the
computer and the radio when used at a base
station, and an interface between the radio and
the datalogger at a field station. In a repeater
station, the RF95A is an interface between two
other communication stations.

The RF95A replaces Campbell Scientific's
RF95, DC95 and SDC RF Modems. The
RF95A is compatible with previous modems.
Refer to Appendix F “Equipment Compatibility"
for compatibility considerations. The RF95A is
the same RF modem as the RF95, except the
RF95A strobes power to the RF300 radio and
uses a different operating system. This is done
to reduce current consumption and extend
battery life. The RF95A should be used with the
RF300 radio.

3.1.1 PHYSICAL DESCRIPTION

The front panel of the RF95A is shown in Figure
3-1. There are two ports for interfacing external
devices. The port labeled TRANSCEIVER
connects to the radio, and the port labeled
SERIAL I/O connects to the datalogger,
PS512M or CH512R in the case of a repeater or
phone-to-RF base station. The red light labeled
CARRIER DETECT is used primarily to indicate
when a carrier frequency has been detected by
the radio. The RF95 to RF100/RF200 cable is
different than the RF95A to RF300 cable.

3.1.2 RF95A STATES

The RF95A Modem operates in one of two
separate states. The RF95A can be utilized in
either the RF95A-ME (Modem Enable) state or
the RF95A-SDC (Synchronous Device
Communication) state. The proper state must
be determined before employing the RF95A in
the field. A switch inside the RF95A needs to
be set accordingly.

The RF95A-ME state is ALWAYS used with
21X and CR7 dataloggers. The RF95A-ME
state is NORMALLY used with all dataloggers.
SDC compatible dataloggers (CR10, CR10X,
CR23X, CR510, and CR500) can also use the
RF95A-SDC state. The SDC state has the
advantage that a phone-to-RF base station can
have measurement capability. Only the RF95A
at a phone-to-RF base station with
measurement should to be switched to the
RF95A-SDC state.

A switch with nine different dip switches is
inside the RF95A; the RF95A cover must be
removed to locate the switch. The ninth switch
sets the RF95A state. The RF95A-ME state is
chosen by setting the ninth dip switch open,
represented by 1. The RF95A-SDC state is
chosen by setting the ninth dip switch closed,
represented by 0. Refer to Figure 3-2.

RF95A

FIGURE 3-1. The RF95A Modem

3-1

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

TABLE 3-1. A Sample of Station ID Numbers

and the Corresponding Switch Settings

Station Switch Settings

ID 1234

0 0000 0000X
10 0101 0000X
20 0010 1000X
30 0111 1000X
40 0001 0100X
50 0100 1100X
60 0011 1100X
70 0110 0010X
80 0000 1010X
90 0101 1010X

100 0010 0110X
110 0111 0110X
120 0001 1110X
130 0100 0001X

* Station ID 255 is reserved for

phone-to-RF base stations.

The RF95A is shipped with the switch set for
the RF95A-ME state and station ID of 1.

Further information on the RF95A compatibility
with older Campbell Scientific equipment can be
found in Appendix F “Equipment Compatibility.”

3.1.3 SETTING STATION ID

Each RF95A, including the one in the RF base
station, must have a unique Station ID. The
station ID is similar to a phone number. This
allows one base station to communicate with
any one particular field station.

The Station ID can be any number from 1 to

255. The Station ID is set with the switch inside
the RF95A. The first eight dip switches are
used to set the Station ID. Table 3-1 shows the
switch settings for several Station ID numbers.
Appendix A shows all possible Station ID
numbers. The dip switches can either be open,
represented by 1, or closed, represented by 0;
X in Table 3-1 refers to "don't care." The ninth
dip switch is set according to the desired RF95A
state, see Section 3.1.2 "RF95A States." All
RF95s are shipped with a Station ID of 1 and
are set in the RF95A-ME state. RF95s inside
the RF base station ship with a station ID of 254
and RF95A-ME state.

56789

3.1.4 THE CARRIER DETECT LIGHT

3.1.5 DATA TRANSFER RATE

FIGURE 3-2. Setting the Station ID

The Carrier Detect light on the front panel of the
RF95A has several purposes. The primary
function of the light is to indicate when data is
being received or transmitted. The light will stay
on when a network frequency originating from
another RF95A is detected. If a signal is
detected which isn't intended for that station, the
light will shut off after about two-tenths of a
second.

The Carrier Detect light can also be used to
check the RAM (Random Access Memory) and
ROM (Read Only Memory) of the RF95A. With
the radio disconnected and the datalogger in
the LOG (*0) Mode, connect the datalogger to
the RF95A Serial I/O Port with a 9-pin ribbon
cable. The sequence of the light flashing after
connection indicates the RAM and ROM status.

Both the RAM and ROM are good if the light
goes on for one second, off for one second, and
then back on for one second. The RAM is
faulty if the light is on for one half second and
off for one half second, continuously. The ROM
is faulty if the light goes on for one second, off
for one half second, on for one half second, and
then off for one half second, continuously.

The data transfer rate is the time it takes to get
data from the datalogger to the computer. In
general, data can be transferred at a rate of
about 30 data points/second (60 bytes/second)
without a repeater. If a repeater is used, an
approximate data transfer rate is 22 data
points/second.

3-2

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

3.1.6 RF95A MODEM COMMUNICATION PROTOCOL

Comprehension of this section is not
necessary for routine operation of the
RF95A Modem. The PC208W Datalogger
Support Software accounts for the
necessary communication protocol.

There must be an RF95A Modem at both the
calling (or computer) end of the transmission
link, and at the answer (or datalogger) end of
the transmission link. The modem at the calling
end is the Start Of Link (SOL) modem, and the
modem at the answer end is the End Of Link
(EOL) modem.

RF95A Modems must also be used at repeater
stations. These RF95A Modems are termed
Middle Of Link (MOL) modems.

The RF95A Modem has five general modes of
operation:

• Wait Mode

• Local Command Mode

• Repeater Mode

• End of Link Mode

• Transparent Mode.

The RF95A is in the Wait Mode of operation
when it is waiting to enter one of the four other
modes of operation. The Wait Mode is entered

1) after the power-up sequence is completed, 2)
following the "T" command when in the Local
Command Mode, and 3) when the system is
reset by the Time-out Timer. The Time-out
Timer is a 60-second timer which is set every
time a valid transmission block is received on
the RF link. The datalogger, being in
Telecommunications Mode, will override the
Time-out Timer.

The Local Command Mode is used to set up
and shut down an RF link. The Local
Command Mode is entered when the
datalogger goes into Telecommunications Mode
after being in the Wait Mode. In this mode the
RF95A responds to command characters
received on the Serial I/O port.

Serial I/O port are organized into data blocks for
transfer through the RF link.

The Repeater Mode is entered by MOL RF95A
Modems. The function of the Repeater Mode is
to receive and then transmit data blocks. The
signature of each data block is checked before
being sent to the next RF station. The block is
discarded if the signature of the data block is
incorrect. The RF95A enters the Repeater
Mode when it receives a valid setup block that
sets the RF95A as a repeater.

The End Of Link Mode is entered when the
RF95A receives a valid setup block that sets the
RF95A as the EOL modem. Upon entering the
EOL Mode, the RF95A brings the Serial I/O
Ring line high which raises the datalogger ME
line, thus causing the RF95A to enter the
Transparent Mode. The Ring line is reset after
the ME line comes high.

3.1.7 RF95A Modem and the RF Link

The RF link is the communication path which is
opened between the Start Of Link modem and
the End Of Link modem, along with any Middle
Of Link modems. Any RF link must first be
established, then maintained, and finally shut
down.

When collecting data, PC208W establishes,
maintains, and shuts down the RF link as
discussed below.

3.1.7.1 Establishing the RF Link

The SOL RF95A is first brought into the Local
Command Mode of operation. In the RF95A­ME State, this is done when the ME line is high
on the Serial I/O port and the SOL modem is in
the Wait Mode of operation. After the ME line is
brought high, the baud rate of the SOL modem
is set by repetitively pressing [ENTER]. The
SOL modem can operate at 300, 1200, or 9600
baud. When the baud rate is set, the SOL
modem will respond by sending a carriage
return line feed (CR-LF) and an exclamation
point (!). In the RF95A-SDC State, the Local
Command Mode is entered after addressing.
Some explanation is contained in Appendix E
"RF95A States."

The RF95A is in the Transparent Mode after
the RF link has been established. In the
Transparent Mode, any data received on the

In the Local Command Mode, the SOL modem
responds to command characters received from
the terminal or computer. The command

3-3

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

characters are summarized in Table 3-2. All
command characters must be capital letters.

TABLE 3-2. RF95A Command

Character Summary

Command Description

E Exit Link Command. The "E"

command causes the datalogger
to drop its ME line and shut
down the RF link.

F Fast Command. The "F"

Command is placed at the end
of the string of setup numbers.
In the RF95A-ME State, the
Serial I/O port of the EOL
modem will communicate with
the datalogger at 9600 baud with
the "F" Command. In the
RF95A-SDC State, the baud
rate from the computer to the
SOL modem will be 9600.

R Read Command. The "R"

Command reads back the
Shutdown Block.

S Link Setup Command. The Link

Setup Command is followed by
a string of setup numbers
representing the ID numbers of
the modems in the RF link.

T Terminate Command. The "T"

Command will reset the SOL
modem to the Wait Mode of
operation.

U Old Link Command. The "U"

Command will force RF
communication between radios
to 2400 baud rather than 3000
baud. DC95s purchased before
February 1989 can only be used
at 2400 baud. For further
information see Appendix F.

W Wait Command. The "W"

Command will force the RF
modem to wait until there is no
carrier detect before transmitting.

The first step in setting up an RF link, once in
the Local Command Mode, is to create a setup

block using the "S" command. The setup string
is entered via the computer as follows:

Sxxx yyy

where:

xxx = ID number of the RF95A which is

acting as the repeater in the link.
If no repeater is used then xxx is
omitted.

yyy = ID number of the EOL modem.

xxx and yyy are numbers from 1 to 255,
inclusive. The user can have up to 12 repeaters
in any RF link. Example 3-1 shows the setup
block for an RF link which will communicate
through three repeaters to an EOL modem, with
Station ID numbers of 10, 25, 50, and 30,
respectively. The Fast Command is used to
speed data transfer.

EXAMPLE 3-1. A Sample Setup Block

S10 25 50 30F

Notice that it is not necessary to include the
station ID of the SOL modem.

Press [ENTER] following the setup string of
station IDs to transmit the setup block. When
the RF link is established, a verification block is
sent from the EOL modem to the SOL modem.
Upon receiving this verification block, the SOL
modem and EOL modem have entered the
Transparent Mode of operation. At this point,
the dollar sign prompt "$" will be returned to the
computer screen. The datalogger connected to
the EOL modem is now in the
Telecommunications Mode and will respond to
the standard datalogger telecommunications
commands. If the verification block does not
return shortly, pressing [ENTER] will cause the
SOL modem to return to the Local Command
Mode.

3.1.7.2 Maintaining the RF Link

Data can be transferred once the RF link is
established. Data blocks are created and
transmitted by the SOL and EOL modems
according to the following two rules. First,
characters received on the Serial I/O port are
placed into data blocks of 238 characters each.
The block is then closed and transmitted. Any
remaining or new characters received at this
point are placed into a new data block. Second,
if during this loading process a delay of 290 ms

3-4

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

occurs between characters, the data block will
be closed and transmitted.

Most of the time, the SOL modem will be
sending command strings which will be
answered by the EOL modem and the
datalogger. The response from the datalogger
is not instantaneous. If a command is sent
before the response from the previous
command has been received, the current
command will be sent and a possible collision of
the RF signal may occur. This results in a loss
of the response and the current command. The
general rule is that the person sending
characters should wait for the response to come
back before issuing further commands.

3.1.7.3 Shutting Down the RF Link

Sending the "E" character to a datalogger
causes the datalogger to drop its ME line, which
causes a shutdown of the RF link.

A shutdown block is created by the EOL
modem which can be sent to the computer as
an indicator of communication quality. The
shutdown block consists of three RF Link
Quality Accumulators (RLQA). Each RF95A in
the link will have three RLQAs which are
appended to the shutdown block. The RLQA
from each RF95A are representative of the
active period of the link. The first three RLQAs
represent the EOL modem connected to the
datalogger, the following sets of numbers will be
for any MOL modems (in order of occurrence
from the EOL modem), and last will be the SOL
modem. A description of the shutdown block is
contained in Table 3-3.

TABLE 3-3. Summary of the Shutdown

Block

xxxx yyyy zzzz

xxxx = Number of

communication failures.
yyyy = Noise level indicator.
zzzz = Noise level indicator.

The noise level indicators are reset and
subsequently become active in the respective
EOL and SOL modems as the Transparent
Mode is entered (immediately after setup). The
MOL modems are reset and become active
when the setup block is propagated to the next
station in the RF link.

After the "E" character is received by the
datalogger a CR-LF is sent through the RF link
to the SOL modem. The shutdown block
follows after a one second delay. When the
shutdown block is received and verified the SOL
modem will leave the Transparent Mode and re­enter the Local Command Mode, indicated by
sending an exclamation point (!) to the
computer.

The shutdown block can be viewed by sending
the "R" command. Example 3-2 illustrates a
shutdown block for three RF95s.

EXAMPLE 3-2. Sample Shutdown Block

!R

EOL modem - > 0004 0110 0097
MOL modem - > 0002 0108 0090
SOL modem - > 0000 0105 0093
!

The first line of numbers, which are the first
three RLQAs, represent the EOL modem. The
second line represents a MOL modem, and last
is the RLQAs for the SOL modem. The 0004
indicates that four interruptions occurred on the
EOL modem while the link was active.
Interruptions are non-data blocks such as voice
transmissions on the same carrier frequency.
All noise level indicators are within acceptable
bounds in this example.

The "T" command should now be used to reset
the SOL modem to the Wait Mode of operation.
This step should not be done if further calls are
going to be made through a phone modem.

3.1.8 RF95A CONNECTIONS

A communication failure occurs when a
signature of a block of data doesn't match its
original signature. These blocks are
subsequently retransmitted. The noise level
indicators should be 102 (±70) at the standard

3.0K baud rate, or 124 (±70) at 2.4K baud.

The 9-pin Serial I/O connector is normally used
to connect the RF95/A to the datalogger,
PS512M or CH512R. Table 3-4 describes the
9-pin connections. The 10-pin rectangular
connector is for connection to the transceiver.
The RF300 transceiver cable has a different pin
out then the RF100/200 transceiver cable.

3-5

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

Appendix H contains the pin out for the radio to
modem cables.

TABLE 3-4. RF95/A Serial I/O to Datalogger

Connector Description

Pin Description
1 +5 V: Supply from external source

2 GND: Ground
3 Ring: Ring to datalogger
4 RXD: Transmit from RF95A
5 ME: Modem Enable from datalogger
6 Printer Enable: Not used
7 Unload Enable: Not used
8 Tape Enable: Not used
9 TXD: Received by RF95A

3.2 RF300 RADIOS

3.2.1 RADIO DESCRIPTION

The RF300 is used in Campbell Scientific's RF
applications to transmit and receive data blocks.
The radios are shipped from Campbell Scientific
secured on a mounting bracket designed to
fasten on the top of the RF modem (see Figure
3-3).

The mounting bracket also supports a BNC
Jack connector from the radio. The coax cable
that is required to connect the radio to its
antenna should be connected to the radio at this
BNC connector. See Section 3.3 for more
information on the antenna cable.

The RF300 Radios are connected to the RF
modem by a special radio cable. The first 10­pin connector on this radio cable has a red and
black wire coming out of the connector. This is
the 10-pin connector (labeled "radio") that
should be connected to the radio. The red and
black power wires should be connected to 12V
and Ground respectfully. The second 10-pin
connector (labeled "RF modem") should be
connected to the RF modem.

3.2.2 RADIO SPECIFICATIONS

The RF300 radios are manufactured by
Johnson Data Telemetry (JDT). Campbell
Scientific modifies the radios to work with the
RF95A Modem. Appendix H contains the radio
specifications.

3-6

RF300

FIGURE 3-3. RF300 On Bracket With Connector

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

3.2.3 RADIO INSTALLATION

The RF300 Radios are shipped from Campbell
Scientific mounted on a special bracket with a
cable going from the radio to a BNC connector
(see Figure 3-3). The following steps will install
a radio for a field or repeater station.

1. Secure the radio and its bracket using the
four screws from the RF95A Modem's lid.

2. Connect the 10-pin connector (with the red
and black power leads coming out of it) of
the radio/RF modem cable into the radio.

3. Connect the second 10-pin connector of the
cable into the RF modem.

4. Connect the red and black power leads
from the radio cable to the 12V and Ground.

5. Route the BNC end of the antenna cable
through the enclosure conduit. Connect the
cable to the BNC Jack connector secured
on the radio mounting bracket.

3.3 ANTENNAS AND CABLES

Antennas radiate and receive the radio signals.
Each radio in an RF telemetry system must
have an antenna. Coax cable is used to
connect the antenna to the radio.

3.3.1 ANTENNA MOUNTS

omnidirectional antenna will be a straight
cylindrical rod which is to be mounted vertically
at the top of a tripod.

A unidirectional antenna is designed to
transmit/receive in a particular direction, or in a
specified sector. There are various shapes of
unidirectional antennas. The most common is
the Yagi antenna (see Figure 1-2). The
elements of a Yagi antenna can be mounted
either vertically or horizontally, corresponding to
either vertical or horizontal polarization.

FIGURE 3-4. The PD237 Crossover Plate

Antenna Mount

Antennas must be mounted above any
surrounding buildings or obstacles. Antennas
must be properly oriented in relationship to the
other antennas for RF communications to work.
Antennas have various mounting options.
Table 3-7 lists mounting specifications for
several common Celwave antennas. Specific
questions regarding antennas can be directed
to Campbell Scientific, Inc. or Celwave.
Celwave's address and phone numbers are:

Celwave
Route 79
Marlboro, NJ 07746
[phone] or [phone]
FAX [phone]

3.3.2 ANTENNA ORIENTATION

Antennas must be oriented correctly to allow
communication between RF sites. First
determine if your antenna is omnidirectional or
unidirectional.

An omnidirectional antenna will transmit/
receive in a full 360 degree circle. Generally, an

Normally, all antennas will be mounted with
vertical polarization. Whichever polarization is
used, be sure to keep antennas at all sites
identically polarized.

3.3.3 ANTENNA CABLES AND CONNECTORS

The most common cable type to connect a
radio to the antenna is a coaxial RG-8A/U
cable. Two connectors are required for each
length of cable. The connector for the radio is a
BNC type connector. The connector for the
antenna is usually either a Type-NM or Type­NF. The BNC, Type-NM, and Type-NF
connectors are shown in Figure 3-6. The Type­NM (male) connector is for antennas with a
female receptacle, and Type-NF (female) for
antennas with male receptacles.

A Campbell Scientific antenna cable complete
with connectors is specified as either COAX
NM-L or COAX NF-L. COAX NF-L is a coaxial
RG-8A/U cable with a BNC connector on one
end and a Type-NF connector on the other.

3-7

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

See Table 3-7 for cable requirements for
common antennas.

Due to power loss through the cable, the length
of coax cable cannot be extended to any
desired length. The amount of power loss is
dependent on the radio frequency. RG-8A/U
will lose approximately 3.1 dB/100 ft. at 200
MHz and 5.0 dB/100 ft. at 400 MHz. Power loss
calculations are reviewed in Appendix C.

FIGURE 3-6. Type-NM (male), BNC, and

Type-NF (female) Connectors

FIGURE 3-5. The PD46 Clamp Mount

TABLE 3-7 Common Antennas and Characteristics

VHF or Pipe Mounting

Antenna Type UHF Cable Gain(dB) O.D. Type

BA1010 Omni VHF Coax NM-L Unity 3/4" - 2 1/8" U-Bolts
BA1012 Omni VHF Coax NM-L Unity 1" - 2 1/4" U-Bolts
BA1312 Omni VHF Coax NM-L 3.0 1" - 2 1/4" U-Bolts
BA6012 Omni UHF Coax NM-L Unity 1" - 2 1/4" U-Bolts
BA6110 Omni UHF Coax NM-L Unity 3/4" - 2 1/8" U-Bolts
BA6312 Omni UHF Coax NM-L 3.0 1" - 2 1/4" U-Bolts
PD200 Omni VHF Coax NF-L 5.8 1" - 2 3/4" PD46 (Fig 3-5)
PD201 Omni UHF Coax NF-L 5.0 1" - 2 3/4" PD46 (Fig 3-5)
PD220 Omni VHF Coax NF-L 5.25 1" - 2 3/4" PD46 (Fig 3-5)
PD344 Dipole VHF Coax NF-L 4.5 2 1/2" Clamps
PD390S Yagi VHF Coax NF-L 8.0 1 5/16, 2 1/4, or 2 3/8 PD37 (Fig 3-4)
PD400 Omni VHF Coax NM-L 7.5 1" - 2 3/4" PD46 (Fig 3-5)
PD688S Yagi UHF Coax NF-L 10.0 1 5/16" - 2 1/4" U-Bolts
PD1107 Omni VHF Coax NF-L 3.0 1" - 2 3/4" PD46 (Fig 3-5)
PD1121 Dipole VHF Coax NF-L 3.0 2 1/2" Clamps

3-8

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

3.4 TRIPODS, TOWERS, ENCLOSURES, AND POWER SUPPLIES

There are several methods of mounting and
housing sensors and other equipment for a
station.

3.4.1 TRIPODS AND TOWERS FOR MOUNTING

For the different mounting requirements,
Campbell Scientific offers the CM6 Tripod,
CM10 Tripod, UT10 Tower, and UT30 Tower.
All mounting options available from Campbell
Scientific are rugged instrument mounts that
provide sturdy support for Campbell Scientific
sensors, enclosures, and measurement
electronics. The CM6 and CM10 Tripods can
be used as a portable instrument mount in a
variety of applications. The UT10 and UT30
Towers provide a more sturdy long-term
support.

3.4.2 ENCLOSURES

Enclosures are needed to keep water and
debris from damaging the data acquisition
equipment. Campbell Scientific, Inc. enclosures
are designated as “rain-tight,” and are designed
to mount to a tripod or tower. Following is a
description of the standard enclosures.

3.4.2.1 CR10X and CR23X Enclosures

Campbell Scientific offers two enclosures for
housing a CR10X or CR23X and peripherals.
The fiberglass enclosures are classified as
NEMA 4X (water-tight, dust-tight, corrosion­resistant, indoor and outdoor use). A 1.25”
diameter entry/exit port is located at the bottom
of the enclosure for routing cables and wires.
The enclosure door can be fastened with the
clasp for easy access. The enclosure’s clasp
door can be secured with a basic lock. Both
enclosures are white for reflecting solar
radiation, reducing the internal temperature.

The Model ENC 12/14 fiberglass enclosure
houses the CR10X and power supply, and one
or more peripherals. Inside dimensions of the
ENC 12/14 are 14" x 12" x 5.5", outside
dimensions are 18" x 13.5" x 8.13" (with
brackets); weight is 11.16 lbs.

The model ENC 16/18 fiberglass enclosure
houses the CR10X or CR23X and power
supply, and two or more peripherals. Inside
dimensions of the ENC 16/18 are 18" x 16" x

8.5." Outside dimensions are 21.75" x 21" x 11"
(with brackets); weight is 17.2 lbs.

3.4.2.2 CR7 Enclosures

Most CR7 radiotelemetry applications have
special needs depending on the individual
system. The ENC-24 is normally used in CR7
RF applications. Contact Campbell Scientific's
customer service department for special
applications.

3.4.3 POWER SUPPLY

A radiotelemetry network requires a reliable
power supply at each station. A solar panel or
110/220 VAC charging source is normally
required due to the large current drain of the
radio.

3.4.3.1 Lead Acid Batteries

Lead acid batteries are designed to be float
charged by a solar panel or AC power source.
The role of the lead acid battery is to supply
power when the charging source is absent, e.g.,
in case of power failures (AC charging), or
during times of zero charge with a solar panel.

21XL and CR7 lead acid batteries do not have
the required capacity for a typical RF station,
they are only 2.5 Amp-hour batteries.
Generally, we recommend a minimum of 7
Amp-hour batteries for RF applications.

3.4.3.2 PS12LA Lead Acid Power Supply

The PS12LA power supply includes a 12V, 7.0
Amp-hour lead acid battery, AC transformer,
and a temperature-compensated charging
circuit with a charge indicating diode. An AC
transformer or solar panel should always be
connected to the PS12. The charging source
trickle charges the lead acid batteries which
power the datalogger. The internal lead acid
battery continues to power the datalogger if the
charging source is interrupted. The PS12LA
specifications are given in Table 3-8.

The two leads from the charging source can be
inserted into either of the CHG ports, polarity
doesn’t matter. A tranzorb provides transient
protection to the charging circuit. A sustained
input voltage in excess of 40V will cause the
tranzorb to limit voltage.

Some solar panels are supplied with a
connector. This connector must be clipped off

3-9

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

so the two wires can be inserted into the two
terminal ports.

The red charge light is on when AC power or a
solar panel is connected to the PS12. If the
input voltage is high enough, the battery will
charge even when the datalogger is on.

CAUTION: Switch the power to OFF
before disconnecting or connecting the
power leads to the Wiring Panel. The
Wiring Panel and PS12LA are at power
ground. If 12V is shorted to either of these,
excessive current will be drawn until the
thermal fuse opens.

The external port, labeled EXT, is not meant to
be used with the PS12LA. The primary power
source is the charging source, and the
secondary power source is the internal lead
acid battery. Connecting a lead acid battery to
the external source is the same as connecting
two lead acid batteries in parallel, causing one
battery to drop voltage and the other to raise
voltage. Alkaline batteries connected to the
external port would be charged by the charging
source, which can cause an explosion.

CAUTION: Do not use the external port,
labeled EXT, with the PS12LA.

Monitor the power supply using datalogger
Instruction 10. Users are strongly advised to
incorporate this instruction into their data
acquisition programs to keep track of the state
of the power supply. If the system voltage level
consistently decreases through time, some
element(s) of the charging system has failed.
Instruction 10 measures the voltage of the lead
acid battery. External power sources must be
disconnected from the CR10 and charging
circuit in order to measure the actual lead acid
battery voltage.

TABLE 3-8. PS12LA Battery and AC

Transformer Specifications

Lead Acid Battery

Battery type Yuasa NA 7-12
Float life @ 25°C 5 years typical
Capacity 7.0 Amp-hour
Shelf life, full charge Check twice yearly
Charge time, (AC Source) 40 hr. full charge

20 hr. 95% charge

AC Transformer

Input: 120V AC, 60 Hz
Isolated output: 18V AC @ 880 mA

max.

3.4.3.3 PS512M Voltage Regulator with Null
Modem Ports.

The PS512M 12 Volt Lead Acid Power Supply
with Charging Regulator and Null Modem Ports
is used when 5 Volts is needed to power
external modems besides the capabilities of the
PS12LA. The PS512M supplies 5 Volts to pin 1
of the 9-pin null modem ports, otherwise the
capabilities and functions are identical to the
PS12LA. A common use for the PS512M is in
radiotelemetry networks. The PS12LA cannot
be modified to the PS512M. The maximum
current drain on the 5 Volt supply of the
PS512M is 150 mA.

3.5 RF232A BASE STATION

3.5.1 RF232A INTRODUCTION

The RF232A Base Station provides a "single
box" desktop base station with the following
features:

• Internal RF modem.

• 25-pin RS232 port for connection to IBM

PC.

• 110 VAC/12 VDC transformer and mount
for the base radio.

• Easy access to radio for antenna cable
connection.

3-10

The RF232A Base Station includes an RF
Modem with a carrier detect light. The RF
Modem sits directly behind the RF232A front
panel. For a description of the Carrier Detect
Light and the communication protocol, refer to
Section 3.1. The RF Modem comes shipped
from the factory with a Station ID number of

254. Under most circumstances there is no

need to change this address.

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

The RF232's 25-pin female port connects to the
computer's 25-pin RS232 port. The RF232A's
25-pin port is configured as Data
Communications Equipment (DCE) for direct
cable connection to Data Terminal Equipment
(DTE), such as an IBM-PC serial port. Table
3-9 shows the pin description.

3.5.2 220, 230, AND 240 VAC CONVERSION

The RF232 can be used with 220, 230, or 240
VAC if a small wiring modification is done.

1. First, disconnect any AC power!

2. Lift the cover off the RF232A and locate the
power supply (P/N 4918) as shown in
Figure 3-8.

3. Unscrew the four Phillips head screws on
top of the power supply and turn the power
supply upside down.

4. Clip the wire ties holding the power supply
leads to the base.

5. With the power supply on its back, locate
pins 1 through 5. The power supply is
shipped from the manufacturer configured
for 120 VAC with pins 1 and 3 jumpered,
pins 2 and 4 jumpered, and AC power
coming onto pins 1 and 4. These
connections must be desoldered.

TABLE 3-10. RF232A Power Conversions

Pins Jumpered Apply AC

110 VAC 1-3, 2-4 1-4
120 VAC 1-3, 2-4 1-4
220 VAC 2-3 1-5
230 VAC 2-3 1-4
240 VAC 2-3 1-4

6. Resolder the pins as shown in Table 3-10
for the Power Conversion you require.

TABLE 3-9. Pin Description for RF232A's

25-Pin Port

Pin I/O
1 − Ground

2ITX
3ORX
4 I RTS
20 I DTR
22 O RING

Description

FIGURE 3-7. The RF232A Base Station

3-11

SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS

RF232A TOP VIEW

3-12

FIGURE 3-8. Top View of the RF232A Base Station

SECTION 4. OPERATION OF THE RADIOTELEMETRY NETWORK

All field stations can be accessed and monitored from the central base site. Regular visits to the field
sites are required to ensure that all sensors are in place, enclosures are dry, solar panel is clean, and
that the tripod and antenna are secure. Frequency of visits to the field sites are variable depending on
environmental conditions and the sensors utilized.

This section of the manual includes a description of the PC208W Datalogger Support Software as it
applies to RF applications, as well as a description of some special RF applications.

FIGURE 4.1-1 PC208W Main Tool Bar

4.1 MONITORING AND COLLECTING DATA - PC208W RF NOTES

The PC208W Datalogger Support Software is
the key to communicating with the field stations.
Complete information on the PC208W Software
is included in the PC208W Manual. This
section gives a brief description of software
setup, specific RF application notes, and data
collection methods.

4.1.1 BASIC CONCEPTS

PC208W is designed to use a unique
communication path for each datalogger field
site. Setup communication parameters and a
communication path for each datalogger you
will service. In the Setup Window of PC208W,
see the Device Map. The Device Map shows
each communication path. A typical RF
communication path will start with the RS232
port, usually listed as COM1 or COM2. The
next item in the typical communication path is
the RF Modem, RF95A. After the RF Modem,
each datalogger is connected to the RF
Modem. The name and address (“Dialed using
RF Path”) of each datalogger can be changed.

4.1.2 USING PC208W SETUP WINDOW

This section covers the basic RF
Communications Path. The RF path must be
setup for PC208W to communicate with an RF
field site. See section 2.2.2 for additional
information about the setup window. To create
an RF communication path, open the Setup
Window of PC208W. Next select the COM

port. If you need an RS232 port other than
COM1, use the “Add COM Port” button. Use
the “Add Device…” button to add your RF
modem or Phone modem to the COM port. The
Add Device button opens the “Add New Device”
Dialog box. Once a device is selected the
“Attach Selected Device to” box is opened.
When adding a device you must attach it to a
device in bold lettering. The last device to add
is a datalogger. Using the Add Device button,
add the appropriate datalogger. The
dataloggers are attached to the RF Modem.
Many dataloggers can be attached to one RF
Modem. If a mistake is made, highlight the
mistaken device in the Device Map and use the
Delete button.

There are several fields requiring unique
settings. PC208W Setup window shows
different options based on which device is
selected in the Device Map. Select a device by
left clicking your mouse on the device. Do not
change any settings for the COM port unless
you are doing Callback. Select the RF modem,
the default name is RF1. Using the “RF Modem
Name” box, you can change the name of the
RF modem. The “Baud rate” box can be used
to change the communication rate between the
RF modem and the datalogger. Select 9600
baud for the RF95 and RF95A RF modems.
Older RF modems must remain at 1200 baud.
The datalogger has one setting that must be
changed. Select the “Dialed Using RF Path”
box and enter the address of the RF95A. The
address is the value set with the dip switches
inside the RF95A. See section 3.1.3 for details.

4-1

SECTION 4. OPERATION OF THE RADIOTELEMETRY NETWORK

An example of a simple RF path is “32F”. The
F is only used when 9600 baud has been
selected, see above. The 32 is the value of the
dip switch settings inside the RF95A. If your
datalogger is using a security code, add the
code to the “Security Code” box.

4.1.3 AUTOMATED DATA COLLECTION ­PC208W

One feature of PC208W is automated/scheduled
data collection. PC208W can be setup to call
each station based on time. To setup the
scheduler click on the setup button of the main
PC208W tool bar. Using the mouse, highlight
the datalogger of interest in the device map. If
the device map does not have the datalogger
listed, you must setup the datalogger including
the correct RF path. See Section 2.2.2 of your
PC208W manual for details. Using the
Schedule tab of the Setup window, set your
Calling Interval, Next time to Call, etc. If you
have questions concerning a field, press F1
while your cursor is in the field. Figure 4.1.2
shows the Setup window on the Schedule tab.
The current settings show a data collection

interval of 7 days, next time to call is October 31
at 10:00 p.m. If this time is in the past, PC208W
will start calling when the scheduler is turned on.
See the check box next to the datalogger name,
the check box is used to turn scheduled data
collection on and off.

The Primary Retry Interval is the time between
calls when the first call attempt failed. The
Retries Using Primary Interval is how many
times the software will continue to call when the
call fails. The time between each call is the
Primary Retry Interval. After the Retries Using
Primary Interval are used up, PC208W will go
into the Secondary Retry Interval. The
Secondary Retry Interval will continue until the
call is successful or the scheduler is turned off.
The Secondary Retry Interval is usually set to a
longer period, such as a day. The Clock Check
Interval, is used to set the datalogger clock to
match the computer clock. The automatic clock
update should be used with caution, computer
clocks are notoriously bad. The “After Call Do”
box can be used to run data management
software after PC208W is finished collecting
data. See your PC208W manual for details.

4-2

FIGURE 4.1-2. PC208W Setup Window/Schedule Tab

SECTION 4. OPERATION OF THE RADIOTELEMETRY NETWORK

4.1.4 GENERAL COMMUNICATION - PC208W CONNECT WINDOW

General communications include: collect data,
send and retrieve programs, monitor
measurements in real time, graph real time
data, etc. PC208W/Connect window supports
these general communication tasks. First
establish a communication link. This can only
be done after the RF communication path has
been setup in the Setup Window. To establish
a communication link, open the Connect
Window. The Connect Window has three tabs
along the bottom. First select the tools tab then
select the datalogger of interest in the Station
List. Using the Connect button of the Connect

Window, initiate the connect sequence. The
computer is communicating with the datalogger
(on line) when the Terminate button changes to
Disconnect. With the datalogger on line, the
Collect or Collect All buttons will collect data
from the datalogger. The Send and Receive
buttons will send a program to the datalogger or
receive a program from the datalogger
respectively. The set datalogger clock button
will set the datalogger clock to match the
computer clock. The Launch Graphs section
has three buttons used to Launch Graphs of
real time data. The Numeric Display tab will
show real time data. See your PC208W manual
for details on using PC208W.

FIGURE 4.1-3. PC208W Connect Window, Tools Tab

4-3

SECTION 4. OPERATION OF THE RADIOTELEMETRY NETWORK

4.2 DATALOGGER INITIATED COMMUNICATIONS

The datalogger can call the computer to initiate
data collection, sometimes termed "call back."
Instruction 97, Initiate Telecommunications, is
used for this purpose. Call back is commonly
used to initiate data collection under emergency
situations (e.g., water level falls below lower
limit). Call back is not the preferred method for
routine data collection.

The computer must be left on and dedicated to
RF communication to implement the call back
option. Call back instructions are explained in
the datalogger manual. The PC208W Manual
explains the use of call back in a
telecommunications network.

4-4

APPENDIX A. SETTING THE STATION ID

Each RF95, including the one in the RF base station, must have a unique Station ID. Each RF modem
has nine dip switches; the first eight must be set for a particular Station ID. Following is a list of all
possible Station IDs with the corresponding setting of the dip switches. Here, 1 represents open, 0 is
closed, and X is "don't care." RF95 and RF95A switches are identical.

SWITCHES SWITCHES SWITCHES

ID 1234

1 1000 0000X 44 0011 0100X 87 1110 1010X
2 0100 0000X 45 1011 0100X 88 0001 1010X
3 1100 0000X 46 0111 0100X 89 1001 1010X
4 0010 0000X 47 1111 0100X 90 0101 1010X
5 1010 0000X 48 0000 1100X 91 1101 1010X
6 0110 0000X 49 1000 1100X 92 0011 1010X
7 1110 0000X 50 0100 1100X 93 1011 1010X
8 0001 0000X 51 1100 1100X 94 0111 1010X

9 1001 0000X 52 0010 1100X 95 1111 1010X
10 0101 0000X 53 1010 1100X 96 0000 0110X
11 1101 0000X 54 0110 1100X 97 1000 0110X

56789 ID 1234 56789 ID 1234 56789

43 1101 0100X 86 0110 1010X

12 0011 0000X 55 1110 1100X 98 0100 0110X
13 1011 0000X 56 0001 1100X 99 1100 0110X
14 0111 0000X 57 1001 1100X 100 0010 0110X
15 1111 0000X 58 0101 1100X 101 1010 0110X
16 0000 1000X 59 1101 1100X 102 0110 0110X
17 1000 1000X 60 0011 1100X 103 1110 0110X
18 0100 1000X 61 1011 1100X 104 0001 0110X
19 1100 1000X 62 0111 1100X 105 1001 0110X

A-1

APPENDIX A. SETTING THE STATION ID

20 0010 1000X 63 1111 1100X 106 0101 0110X
21 1010 1000X 64 0000 0010X 107 1101 0110X
22 0110 1000X 65 1000 0010X 108 0011 0110X
23 1110 1000X 66 0100 0010X 109 1011 0110X
24 0001 1000X 67 1100 0010X 110 0111 0110X
25 1001 1000X 68 0010 0010X 111 1111 0110X
26 0101 1000X 69 1010 0010X 112 0000 1110X
27 1101 1000X 70 0110 0010X 113 1000 1110X
28 0011 1000X 71 1110 0010X 114 0100 1110X
29 1011 1000X 72 0001 0010X 115 1100 1110X
30 0111 1000X 73 1001 0010X 116 0010 1110X
31 1111 1000X 74 0101 0010X 117 1010 1110X
32 0000 0100X 75 1101 0010X 118 0110 1110X
33 1000 0100X 76 0011 0010X 119 1110 1110X
34 0100 0100X 77 1011 0010X 120 0001 1110X
35 1100 0100X 78 0111 0010X 121 1001 1110X
36 0010 0100X 79 1111 0010X 122 0101 1110X
37 1010 0100X 80 0000 1010X 123 1101 1110X
38 0110 0100X 81 1000 1010X 124 0011 1110X
39 1110 0100X 82 0100 1010X 125 1011 1110X
40 0001 0100X 83 1100 1010X 126 0111 1110X

A-2

APPENDIX A. SETTING THE STATION ID

SWITCHES SWITCHES SWITCHES
ID 1234
41 1001 0100X 84 0010 1010X 127 1111 1110X
42 0101 0100X 85 1010 1010X 128 0000 0001X

129 1000 0001X 172 0011 0101X 215 1110 1011X
130 0100 0001X 173 1011 0101X 216 0001 1011X
131 1100 0001X 174 0111 0101X 217 1001 1011X
132 0010 0001X 175 1111 0101X 218 0101 1011X
133 1010 0001X 176 0000 1101X 219 1101 1011X
134 0110 0001X 177 1000 1101X 220 0011 1011X
135 1110 0001X 178 0100 1101X 221 1011 1011X
136 0001 0001X 179 1100 1101X 222 0111 1011X
137 1001 0001X 180 0010 1101X 223 1111 1011X
138 0101 0001X 181 1010 1101X 224 0000 0111X

56789 ID 1234 56789 ID 1234 56789

139 1101 0001X 182 0110 1101X 225 1000 0111X
140 0011 0001X 183 1110 1101X 226 0100 0111X
141 1011 0001X 184 0001 1101X 227 1100 0111X
142 0111 0001X 185 1001 1101X 228 0010 0111X
143 1111 0001X 186 0101 1101X 229 1010 0111X
144 0000 1001X 187 1101 1101X 230 0110 0111X
145 1000 1001X 188 0011 1101X 231 1110 0111X
146 0100 1001X 189 1011 1101X 232 0001 0111X
147 1100 1001X 190 0111 1101X 233 1001 0111X
148 0010 1001X 191 1111 1101X 234 0101 0111X
149 1010 1001X 192 0000 0011X 235 1101 0111X
150 0110 1001X 193 1000 0011X 236 0011 0111X
151 1110 1001X 194 0100 0011X 237 1011 0111X
152 0001 1001X 195 1100 0011X 238 0111 0111X

A-3

APPENDIX A. SETTING THE STATION ID

153 1001 1001X 196 0010 0011X 239 1111 0111X
154 0101 1001X 197 1010 0011X 240 0000 1111X
155 1101 1001X 198 0110 0011X 241 1000 1111X
156 0011 1001X 199 1110 0011X 242 0100 1111X
157 1011 1001X 200 0001 0011X 243 1100 1111X
158 0111 1001X 201 1001 0011X 244 0010 1111X
159 1111 1001X 202 0101 0011X 245 1010 1111X
160 0000 0101X 203 1101 0011X 246 0110 1111X
161 1000 0101X 204 0011 0011X 247 1110 1111X
162 0100 0101X 205 1011 0011X 248 0001 1111X
163 1100 0101X 206 0111 0011X 249 1001 1111X
164 0010 0101X 207 1111 0011X 250 0101 1111X
165 1010 0101X 208 0000 1011X 251 1101 1111X
166 0110 0101X 209 1000 1011X 252 0011 1111X
167 1110 0101X 210 0100 1011X 253 1011 1111X
168 0001 0101X 211 1100 1011X 254 0111 1111X
169 1001 0101X 212 0010 1011X 255 1111 1111X
170 0101 0101X 213 1010 1011X
171 1101 0101X 214 0110 1011X

A-4

APPENDIX B. ALTERNATE BASE STATION CONFIGURATIONS

The basic base station consists of a computer and the RF232 Base Station. There are other options for
a base station including a portable base station, a phone-to-RF base station, and a phone-to-RF base
station with measurement capability. The RF95A is used with RF300 radios. The RF95 is used with
RF100/200 radios.

B.1 THE PORTABLE BASE STATION

The portable base station is an aid in setting up
a large radiotelemetry network, or in trouble­shooting RF network communication problems.
A portable base station allows any of the field or
repeater stations to act as a base station.
Therefore, to try any particular RF link, it is not
necessary to travel to the fixed base station.

Figure B-1 is a block diagram of a portable base
station. The computer, with PC208W installed,
is the user interface to the RF network.
Remember that the "RF Path" designation will
be changed often to test various RF links. The
SC532 is the interface from the laptop computer
to the RF95A Modem. The transformer on the
SC532 should be cut off 6" up the cable. The
two leads on the SC532 should be stripped and
tinned for connection to a battery. Most laptops
have a 9-pin RS232 port, so a 9- to 25-pin
RS232 cable is needed to connect the
computer to the SC532.

B.2 PHONE-TO-RF BASE STATION

When an RF network is a great distance from
the desired place of data collection, a phone
modem can be used to call the RF base station.
A computer, with PC208W Datalogger Support

Software, and a Hayes compatible phone
modem can call a phone-to-RF base station.
The configuration is shown in Figure B-2.

The Device Map in the Setup Window of
PC2082 must include the following
communication path: COM Port, Phone
Modem, RF Modem, Datalogger. The phone
number and RF Path need to be filled in to
match your setup. The PS512M Power Supply
and Charging Regulator supplies 5 V to the
RF95A, supplies 12 V to the COM200 Phone
modem and RF300 Radio, and acts as a null
modem between the COM200 and the RF95A.
The PS512M and CH512R need to supply 12
volts on Pin 8 of the 9 pin connectors. PS512M
with serial number less than 1712 require a
power adapter, part number 10704. CH512R
serial number less than 1075 also require the
same power adapter. The RF95A and COM200
are both connected to a separate 9-pin port on
the PS512M. The RF95A Station ID at the
phone-to-RF base station must be 255 to allow
more than one field station to be called without
terminating the initial phone link. The RF95A in
the RF95A-ME State recognizes Station ID 255
as a command to answer the phone and hold
the ring line high which keeps the Modem
Enable line high after the Ring from the phone
modem has quit.

B-1

APPENDIX B. ALTERNATE BASE STATION CONFIGURATIONS

FIGURE B-1. Portable Base Station

RF95A

RF300

B.3 PHONE-TO-RF BASE STATION

WITH MEASUREMENT CAPABILITY

When it is desired to have a datalogger at a phone­to-RF base station, the datalogger must be a CR10,
CR10X, CR23X, CR510, or CR500 and the RF95A
must be in the RF95A-SDC State. This
configuration is used when the computer uses a
phone modem to call the RF base station which is
also being used as a field station (because
measurements are being made at the station). The
configuration is shown in Figure B-3.

The Device Map in the Setup Window of
PC208W must include the following interface
devices: COM Port, Phone Modem, RF Modem,
and Datalogger. The Phone number and RF Path

must be set. The COM200 Phone Modem and
the RF95A are connected to and powered by the
Datalogger. The RF95A Station ID at the phone­to-RF base station does not have to be 255 in this
case. This is because the Datalogger will
automatically hold the Modem Enable line high,
not being reliant on the RF95A.

The datalogger at the base station should have
security set. See the Datalogger manual for the
details of security. With security set, a pass­word (number) is required before data can be
collected. Without security set, data can
inadvertently be collected from the base
Datalogger if an RF link fails during
communication with another datalogger.

B-2

APPENDIX B. ALTERNATE BASE STATION CONFIGURATIONS

RF95A

RF300

FIGURE B-2. Phone-To-RF Base Station

RF95A

RF300

FIGURE B-3. Phone-To-RF Base Station With Measurement Capability

B-3

APPENDIX B. ALTERNATE BASE STATION CONFIGURATIONS

This is a blank page.

B-4

APPENDIX C. POWER CALCULATIONS

There must be enough transmission power in any RF link to complete communication. The sources of
power are the radio and the antennas. Conversely, power is lost both through the cables (coax loss)
and over the distance of communication (path loss). The power of the signal received (Signal Power)
can be calculated as stated below.

The signal power must be greater than -95 dBm (-80 dBm @ 2.4K baud) to have a good radiotelemetry
link. Decibel milliwatts (dBm) is a scale of power, 0 dBm represents one milliwatt of power. The lower
limit of power for good data transmission is approximately 0.0000000000003 Watts (3X10-13), which
represents -95 dBm.

Signal Power

SP = TP + AG - PL - CL

where, SP = Signal Power (dBm) Power of the signal received,

TP = Transmit Power (dBm) Rated output power of transmitting radio,

PL = Path Loss (dB) Power lost over the distance of communication (calculated below),

AG = Antenna Gain (dB) Total power gained by both the transmit and receive antennas,

and, CL = Coax Loss (dB) Total power lost through both lengths of cable connecting the

transmit and receive radios to the antennas.

Path Loss

PL = 36.6 + 20*Log(F) + 20*Log(D)

where, PL = Path Loss,

F = Frequency (MHz),

and, D = Distance (miles).

Coaxial Cable Loss

Typical coaxial cable losses are listed below.

200 MHz 400 MHz
Cable Type Loss/100 ft.
RG-8A/U 3.1 dB 5.0 dB
RG-58A/U 6.2 dB 9.5 dB

Transmit Power

5 Watt Radio 36.99 dBm
4 Watt Radio 36.02 dBm

Power Conversion

Conversion of Watts to dBm can be done with the following formula.

dBm = 10 * Log((Watts)/0.001)

C-1

This is a blank page.

APPENDIX D. FUNDAMENTALS OF RADIOTELEMETRY

D.1 RADIO WAVES

Radiotelemetry is the process of transferring
information (data) in the form of radio waves.
The data is transferred on a carrier wave which
normally has a sinusoidal form. Therefore, the
carrier wave can be described entirely by the
frequency, amplitude, and phase with respect to
a reference.

The commonly used term for radiotelemetry,
RF, refers to radio frequency, which in actuality
is the frequency of the carrier wave.

Radio waves can be divided into three
categories: 1) ground waves, 2) direct waves,
and 3) sky waves. All communication with
Campbell Scientific's RF networks are done via
direct waves. Direct waves travel "line-of-sight"
at a maximum distance of approximately 25
miles.

Low frequency radio waves (5-10 mHz) can
travel for thousands of miles using the ground
wave portion of the radio wave. The ground
wave is that portion of the radio wave which
travels just above the surface of the ground.
Conversely, the sky wave radiates to the
ionosphere where a certain percentage of the
energy is reflected back to earth. At the higher
frequencies used for data transmission the
ionosphere is penetrated by the radio wave and
too small of a percentage is reflected back to
earth. However, neither the ground wave or sky
wave is used in Campbell Scientific's RF
networks.

Energy is lost from radio waves as they travel
away from the transmitting antenna. One
reason for this is the loss due to dispersion of
energy over a larger area; analogous to water
waves reducing in size (energy) as they get
farther from the source. Second, is that energy
is absorbed by the earth over the distance of
travel. Eddy currents cut down signal power,
and intervening terrain and buildings can
prevent a signal from being strongly received.

The higher the frequency, the stronger the
radiation field. However, at higher frequencies
more energy is absorbed by the surface. The
VHF and UHF frequencies can travel only a
short distance between radio stations. The

direct wave, where there is no obstacles
between stations, will transmit farther than any
indirect waves which have been transmitted
through or reflected from obstacles.

The carrier wave can be thought of as the radio
wave which "carries" the data from one radio to
the next. The "data" consists of an electrical
signal which rides with the carrier wave. The
process of placing the signal on the carrier
wave is called modulation. The signal is also in
the form of a wave, but usually the signal has a
much lower frequency. The carrier with the
modulating signal is called the modulated
carrier.

The signal wave isn't used as a carrier wave
because radio transmission must be of a high
frequency to keep radio components small,
antennas small, filtering efficient, and to isolate
the radio waves from the common low
frequency man-made noise.

The main forms of modulation are amplitude,
frequency, and pulse modulation. Frequency
modulation (FM) is used by Campbell Scientific.

D.2 ANTENNAS

An antenna is a device which captures and
radiates radio waves. The antenna at the
transmitting station is excited by the transmitting
radio. The antenna converts energy from the
radio to radiated energy. Electrons within the
antenna oscillate at the frequency of the radio
thereby producing radio waves. These radio
waves radiate out from the antenna at the
speed of light (299,800 km/s).

The transmitted radio wave will cause electrons
in the receiving antenna to oscillate at the
carrier frequency. The AC current thereby
produced in the antenna is transferred to the
radio for demodulation.

The antenna is constructed for a particular
frequency, operating radius, and gain. Length,
diameter, number of elements, and element
spacing are among the items that can be
changed to alter antenna performance at the
design stage.

D-1

APPENDIX D. FUNDAMENTALS OF RADIOTELEMETRY

Every antenna has a known horizontal and
vertical pattern of radiation. The horizontal
radiation pattern consists of any segment of a
360 degree circle surrounding the antenna. The
horizontal pattern is important to consider when
a RF station is to communicate with more than
one other RF station. The vertical pattern is the
radiating pattern in the upward and downward
directions.

Any two communicating RF stations must have
a minimum level of signal power. Power is
normally expressed in decibels (dB), or decibel
milliwatts (dBm). Power is lost through
transmission cables (transmitting and receiving)
and over the communicating distance. Power is
gained through the transmitting radio, and the
two antennas. Antenna gain is specified in
decibels in reference to a dipole, and can vary
from 0 to 10 dB in common antennas. A unity
gain antenna has a 0 dB gain, therefore no
additional power is added by using these
antennas.

Antenna gain is accomplished by either
concentrating the radiating power in a small
sector, or using multiple radiating elements with
additive patterns.

D.3 RF95A MODEM

The RF95A Modem is the main communication
control device in a radiotelemetry network. The
RF Modem enables a central base site to
communicate with up to 254 different RF
stations.

The RF Modem is a microprocessor controlled
device which codes all transmissions for a
specific communication path. Each has a
hardware ID switch for identifying different
stations.

The purpose of the RF Modem is to control
operation of the radio and provide protection for
data integrity. The RF Modem controls the
communication sequences, sets data to be
transferred into data blocks, creates signatures
of data blocks, modulates the radio's carrier
wave, and stores information on communication
quality.

The user at the computer is responsible for
naming the desired communication path with a
setup string. This setup string contains any
repeater (MOL) modem IDs and the destination

(EOL) modem ID in sequence. After sending
this information out through the RF system, all
of the RF Modems in the specified link will set
themselves in the proper mode. The RF
Modem has different modes to distinguish
responsibilities at various localities within a link.
These modes are described in Section 3.1.6.

Establishment of an RF link consists of getting
all of the RF Modems in the proper mode and
receiving a verification block from the EOL
modem.

D.4 TRANSCEIVER

The purpose of a transceiver (radio) is to
transmit and receive the modulated carrier
wave.

A radio is both a transmitter and receiver. The
main component in the transmitter is the
oscillator of which the frequency of oscillation is
provided by a crystal. The crystal oscillates at a
desired frequency, which is specific for the
carrier frequency. The oscillator converts DC
power to an AC signal. This signal is then
amplified, modulated with the signal, and
transmitted to the antenna system. The
receiver consists of an amplifier, frequency
converter to slow signal, limiter to give constant
amplitude but same frequency, and
discriminator or demodulator.

The radio has a known impedance, or
resistance. Maximum power is transferred if
the impedance of the radio matches the
impedance of the antenna and cable. This
impedance is generally 50 ohms. Mismatching
of impedance will cause a lesser transmit power
and result in a higher VSWR (Voltage Standing
Wave Ratio).

When the transmission cable and antenna does
not match the impedance of the output circuit of
the radio, not all of the energy fed down the
cable will flow into the antenna. A percentage
of the energy will be reflected back forming
standing waves on the cable. The ratio of
voltage across the line at the high voltage points
to that at the low voltage points is known as the
VSWR. When the VSWR is 3.0:1 or greater,
the percentage of errors per data value is
greater than 50%. The VSWR should be kept
below 1.5:1 for error free radiotelemetry.

D-2

APPENDIX E. RF95A STATES

The RF95A Modem operates in one of two
separate states. The RF95A can be utilized in
either the RF95A-ME (Modem Enable) State or
the RF95A-SDC (Synchronous Device
Communication) State. The RF95A-ME State is
normally used for all RF networks. The RF95A­SDC State must be used when there is a
phone-to-RF base station with a datalogger.
Note: the 21X and CR7 dataloggers don’t
support the SDC state. A switch inside the
RF95A needs to be set according to the chosen
state.

E.1 RF95A-ME STATE

The RF95A-ME State is always used with 21X
and CR7 dataloggers, and normally with all
other dataloggers.

RF95A-ME State Description

The RF95A rings the datalogger until the
datalogger raises the ME line. The Datalogger
waits approximately 40 seconds to receive
carriage returns to establish the baud rate.
After the baud rate is set the Datalogger
transmits a carriage return, line feed, "*", and
enters the Telecommunications Mode. If the
carriage returns are not received within the 40
seconds, the Datalogger hangs up.

When the datalogger is in the
Telecommunications Mode, the ME line is high,
and the RF95A is subsequently in the
Transparent Mode or EOL Mode depending on
the relative location of the RF95A.

Device Enable (SDE, pin 6) lines to establish
communication rather than just the Modem
Enable line.

When the Datalogger is connected to the
RF95A, a 1N command is sent to the
datalogger at setup. The baud rate is set and
the Datalogger completes connections with the
RF95A. The Datalogger sets the RF95A in an
addressing state by raising the CLK/HS followed
by or simultaneously raising the SDE line. The
RF95A drops the ring line and prepares for
addressing.

The Dataloggger then synchronously clocks 8
bits (the address) onto TXD using CLK/HS as a
clock. The least significant bit is transmitted
first, each bit is transmitted on the rising edge of
CLK/HS. The RF95A completes addressing
when the eighth bit is received.

The synchronous device capability enables the
Datalogger to have measurement capability at a
phone-to-RF base station. A command within
the address sent to the RF95A can tell the
RF95A to connect to the phone modem which
requires the RF95A to switch its TXD and RXD
lines. Therefore all characters are routed
through the phone modem to the RF95A which
controls the radio accordingly.

The RF95A then enters the Active State. The
receiver is enabled when SDE and CLK/HS are
high. The transmitter is enabled when SDE is
high and CLK/HS is low.

E.2 RF95A-SDC STATE

The RF95A-SDC State can be used to enable a
Datalogger to be recording measurements at a
phone-to-RF base station. The SDC State is
never used with 21X or CR7 dataloggers.

RF95A-SDC State Description

The RF95A obeys all Synchronous Device
Communication (SDC) protocol when set in the
RF95A-SDC State. Most dataloggers have the
ability to address synchronous devices. The
21X and CR7 do not support the SDC state.
The Datalogger and the RF95A use a
combination of the Ring (pin 3),
Clock/Handshake (pin 7), and Synchronous

In the Active State, the RF95A responds to the
commands S, R, T, F, and U.

E-1

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APPENDIX F. EQUIPMENT COMPATIBILITY

F.1 COMPATIBILITY OF CURRENT AND

PAST RF EQUIPMENT

This section is to aid customers who have older
RF equipment from Campbell Scientific. Table
F-1 lists the different components of past and
current RF systems.

TABLE F-1. Different RF Setups

Oldest Obs. 2nd Obs. 3rd Obs.

RF Setup RF Setup

Radios HT90/ P50 RF100

HT90-SDC RF200
RF Modem DC95 RF95 RF95
Base Station PS232 RF232

A site of one setup will communicate with a site
of another setup as long as the following
conditions are met:

• Both radios are set to the same frequency.

RF Setup

6. A CR10 with old software can be used with
an RF95 in the ME State, however the
datalogger loses the "callback" capability as
well as the SDC function.

F.2 THE "U" COMMAND

The "U" command, or Old Link command, is
only needed if a DC95 with PROM 399B or
399D is being utilized at a field or repeater
station and a newer DC95 PROM or an RF95 is
used at the base station.

When a remote station with an RF95 (or newer
DC95 PROM) is interrogated by a base station
with the older DC95 PROM at the 2400 baud
rate, the remote station detects the 2400 baud
rate and automatically communicates at that
baud rate.

When the base station modem is changed to an
RF95 (or newer DC95 PROM) and there are still
old DC95s in some of the remote stations, then
the "U" command must be used to
communicate with those stations.

• Both antennas are oriented to receive from
the other.

• Both sites are line-of-site of each other.

• Both sites are close enough together for the

signal to transmit.

There are a few basic rules to remember when
interfacing equipment of different setups at the
same site.

1. An RF95 is a direct replacement for a DC95
when used with a 21X or CR7.

2. The RF95 Modem will work with the HT90,
P50, RF100, and RF200 radios.

3. The DC95 Modem will not work with the
P50, RF100, or RF200 radios.

4. Each Base Station will only physically hold
the RF Modem from the same RF Setup.
That is, a PS232 holds a DC95 and an
RF232 holds an RF95.

5. When replacing an HT90-SDC radio, the
CR10 must have current software PROMs.

The DC95 PROM numbers 399B and 399D are
2400 baud, PROM 589-1 in the DC95 enables
3000 baud. The PROM number is written on
the top of the PROM which is located to the left
of the ID switch under the cover of the DC95.

DC95s with the 2400 baud PROMs can be used
only at 2400 baud. The "U" command
preceding the setup string will force
communication at 2400 baud. The "S"
command precedes the U command when used
with the Terminal Emulator. TELCOM and
TERM otherwise add the "S" command
automatically. Example F-1 shows the use of
the "U" command in a setup block. The default,
without a "U" command, is 3000 baud.
Alternatively, DC95s can be updated with
PROM 589-1 to communicate at 3000 baud.

EXAMPLE F-1. Use of the "U" Command

Path: U5 10 12 7

F-1

APPENDIX F. EQUIPMENT COMPATIBILITY

F.3 INCORPORATING THE RF300 AND

THE RF95A

The RF300 is similar to the RF100 and RF200
radios. The 100/200 series uses a Crystal to
generate the carrier frequency and were
manufactured by EF Johnson. The RF300
radios digitally synthesize the carrier frequency
and are manufactured by Dataradio COR Ltd.
(DRL). The DRL radio is modified to work with
the RF95A. RF300 radios can have their carrier
frequency changed using a PC, the RS232 port
and the appropriate software. There are limits
to how far the frequency can be changed.
Contact CSI to purchase a copy of the software.
See Table F-2 for more information.

TABLE F-2. Radio Frequency Range

Frequency

CSI Model #

RF300 150 - 174 3422-510
RF301 132 - 150 3422-410

range, MHz

JDT

Model #

TABLE F-3. Radio/Modem/Cable

Combinations

RF

Radio

RF100/200 RF95 Original RF100/200
RF100/200 RF95A New RF300
RF300 RF95 RF300
RF300 RF95A RF300

Modem Cable

RF302 450 - 470 3412-510
RF303 403 - 419 3412-210
RF304 419 - 435 3412-310

The RF95A is very similar to the RF95. The
RF95A strobes power to the radio. This is done
to conserve battery life. The RF300 radios will
work with the RF95 but will use three times
more quiescent current without the power
strobe, approximately 100 mA. The RF95A
also uses different communications techniques
which benefit the RF300 radios. A RF95A will
work anywhere the RF95 works provided the
correct cable is used, Table F-3.

F-2

APPENDIX G. P50 RADIO

G.1 P50 RADIO SETUP AND

SPECIFICATIONS

The P50 Radio transmits and receives data
blocks. The volume, squelch, and frequency
controls on the radio must be set properly.

G.1.1 VOLUME CONTROL

The volume control should be set to
approximately 1/2 of the operational range.
This is equivalent to approximately 9:00
assuming the off position is at 4:00. Marginal
RF links can be enhanced by "fine tuning" the
volume control at any respective RF station.

G.1.2 SQUELCH CONTROL

The squelch control determines the input power
level that the radio will break squelch. The
squelch control should be set fully clockwise or
approximately 12:30.

G.1.3 FREQUENCY SWITCH

The frequency switch should always be set to 1,
unless you are using a dual frequency system.

G.1.4 P50 SPECIFICATIONS

VHF UHF
Power output 5W 4W
Frequency (MHz) 150-174 450-470
Channel capability 2 2
Dimensions 6.7"x2.5"x1.2" 6.7"x2.5"x1.2"
Weight 15.5 oz 15.5 oz
FCC Designation AZ489FT3729 AZ489FT4724

Current drain
Quiescent 10 mA 1.35 A
Active 15 mA 1.10 A

G.2 ADDITIONAL TROUBLESHOOTING

FOR P50 RADIO

To test a station's radio/cable/antenna
transmission capabilities, a directional
wattmeter is needed such as Bird Electronic
Corporation's Model 4304A Wattmeter. Proper
connectors are also needed to place the
wattmeter in series between the radio and
antenna cable. A voltmeter is required to
measure the battery voltage of the datalogger
with and without radio transmission.

Place the wattmeter in series between the radio
and antenna cable. Set the wattmeter to the 15
Watt range, or the next highest wattmeter
setting, and point the directional arrow first
toward the antenna cable to measure forward
power (Wf). Depress the transmit button on the
radio, let the wattmeter stabilize, and write down
the wattmeter reading. Reverse the directional
arrow so it is pointing back toward the radio,
depress the transmit button, let the wattmeter
stabilize, and write down the wattmeter reading.
This second reading is the reflected power
(Wr). Take the square root of the quantity
reflected power divided by the forward power to
arrive at the square root ratio (R). Calculate the
Voltage Standing Wave Ratio (VSWR) with the
following equation:

VSWR = [(1+R) / (1-R)]

1/2

where, R = (Wr / Wf)

The impedance of the R transmission cable
(usually RG-8A/U) and antenna combination
should match the impedance (50 ohms) of the
radio output circuit. When the transmission
cable or antenna does not match the
impedance of the output circuit of the radio, not
all of the energy supplied to the cable will flow
into the antenna. Some of the energy supplied
will be reflected back to the radio, causing
standing waves on the cable. The ratio of
voltage across the line at the high voltage points
to that at the low voltage points is known as the
Voltage Standing Wave Ratio, or VSWR. The
VSWR should be kept below 1.5:1 for error-free
radiotelemetry.

.

FIGURE G-1. P50 Radio Settings

For example, if the forward power (Wf) is 5
Watts and the reflected power (Wr) is 0.2
Watts, the VSWR is 1.5:1.

G-1

APPENDIX G. P50 RADIO

A problem has been found if the VSWR is greater
than 1.5:1. The VSWR will increase when:

• The antenna is used in proximity of metal

• Transmitting inside a building

• The cable is bad

• The antenna frequency does not match the

radio frequency

• There is a bad connection
If the VSWR is below 1.5:1, then that

radio/cable/antenna link is good. However, be
sure the antenna is oriented properly.

While at the station also check the voltage on the
12 V port both with and without the transmit
button depressed. Regardless of the battery type,
the datalogger requires a minimum of 9.6 Volts.

G.3 TROUBLESHOOTING WITH

ATTENUATION PADS

If stations can be heard breaking squelch on
this base station radio, but communication
quality is poor or not being set up properly,
there many be a marginal or low signal power
inherent in the RF link. In this case, it is a good
idea to do a signal power check with attenuation
pads for each sublink in a complete RF link.
Every RF link has one or more sublinks. For
example, if there is one repeater in an RF link
then there is a sublink between the base station
and the repeater and a sublink between the
repeater and the field station. The sublinks
should be checked in both directions of
communication.

Before proceeding, it is a good idea to calculate
the theoretical signal power for each of the RF
links. Appendix C of the RF Telemetry manual
outlines the calculations.

Signal power must be greater than -95 dBm at
the standard 3.0K baud rate transmission rate,
or -80 dBm @ 2.4K baud. However, squelch
will break on the radios with a power greater
than -115 dBm. Therefore, there is a 20 dBm
range in which the radios are not working, but
may "sound" proper.

An attenuation pad inserted into the link
increases the power loss of the system. If a 20
dBm attenuation pad, or two 10 dBm pads in
series, is inserted into the link and subsequently
the radio will not break squelch, the signal
power is between -95 and -115 dBm which is
below the power limit for good data
transmission.

Similarly, if a 10 dBm attenuation bad is
inserted in the link and the radio subsequently
will not break squelch, the actual signal power is
between -105 and -115 dBm. In this case, the
signal power is far below the power limit. First,
test the sublink of the base station to the first
repeater or field station. Initially treat the base
station as the transmitting station and the first
field or repeater station as the receiving station.
Disconnect the radio's multicolored cable from
the RF modem. With somebody at each
station, depress the base station transceiver
button and listen at the receiving station to hear
if squelch is broken. If squelch is not broken,
then either the signal power is less than -115
dBm, or something is wrong with the power
supply, antenna orientation, or cable
connections. If squelch is broken on the
receiving radio, the site can be tested with the
attenuation pads to determine the approximate
signal power if it is between -115 and -95 dBm.

Insert the attenuation pad(s) (20dBm) between
the radio and antenna of the receiving station
ONLY (most attenuation pads have a limited
current capacity). Depress the base station
transceiver button. If squelch is broken at the
receiving station, this sublink is good in this
direction. If squelch is not broken, this sublink
has signal power between -95 and -115 dBm
which should be corrected. Corrections can
involve shortening distances, reorienting
antennas, providing a better power supply, or
shortening coaxial cable lengths.

If it did not break squelch with the 20 dBm
attenuation pad, it is possible to decrease the
attenuation to 10 dBm to determine if signal
power is between -95 and -105 dBm, or
between -105 and -115 dBm. This will identify if
the signal power is close or far away from -95
dBm.

If it did break squelch with the 20 dBm
attenuation pad, then that sublink is good in that
direction. The next sublink can now be tested.
Remember to place the attenuation pads at the
receiving station only! If all of the sublinks were
good, the same sublinks can be tested in the
opposite direction. If reversing directions in a
sublink gives bad results while the other
direction is good, be suspicious of the
transmitting radio in the bad direction and the
radio's power supply.

G-2

APPENDIX H. RF300 RADIO SPECIFICATIONS

TABLE H-1. RF300 Radio Specifications - UHF

GENERAL

Frequency Range 403 - 512 MHz
Frequency Control Synthesized
Channel Spacing 12.5/25 kHz
Mode of Operation Simplex of Half Duplex
Operation Voltage +13.3V DC nominal (10 -16V DC operational)
Regulated Supply Voltages +5.5V DC, +9.6V DC
Transmit Enable
Receive Enable
Transceiver Enable
Power and Data Connector 15-pin in-line Socket (Dupont 76308-14)
RF Input/Output Connector SMA Jack (female)
Operating Temperature
Storage Temperature
Humidity
Maximum Dimensions 4.585” L, 3.25” W, 2.212” H
FCC Compliance
DM3412 Customer must apply
DL3412 Part 90, Part 15(403-512 MHz), Industry Canada RSS119, Issue 5

3-16V DC at 100 µA Max
3-16 DC ± 5% at 150 µA nominal (150 µA During receive)
3-16V DC at less than 150 µA

-30°C to +60°C

-40° C to + 85° C
95% maximum RH at 40° C, non-condensing

RECEIVER

Bandwidth 16 MHz all bands except (20 MHz 308-405/450-470 MHz)
Frequency Stability
Sensitivity - 12 dB SINAD
RF Input Impedance 50 ohms
Selectivity -70 dB/-60 dB (tN/t/E) for 25 kHz, 60 dB/50db (tN/t/E) for 12.5 kHz
Spurious and Image Rejection -70 dB
Conducted Spurious Emissions <-57dBm
Intermodulation -70 dB
FM Hum and Noise -40 dB 12.5/25 kHz
Receive Attack Time < 5 ms
Total Receive On Time 7 mS Maximum
Audio
Distortion <3%
Buffered Output Level 150 mV RMS nominal at 2.5V DC bias
Discriminator Output
Output Bias
Output impedance >10k Ohms
RSSI 0.9V to 2.4V DC output from -120 to -60 dBm, attack time < 2 ms

±1.5 PPM (-30° C to +60°C)
≤ 0.35 µV

±1 dB from DC to 5 kHz (reference to 1 kHz)

2.5V DC ±10%

H-1

APPENDIX H. RF300 RADIO SPECIFICATIONS

TRANSMITTER

Frequency Stability
Bandwidth 16 MHz without Tuning, 20 MHz without tuning 380-403 & 450-470

Maximum System Deviation 5 kHz (25 kHz), 2.5 kHz (12.5 kHz)
Modulation FM/DC coupled
Input Bias

Input Impedance >40k
Distortion <3% at 60% of maximum system deviation, 1 kHz tone
Capability
Flatness

RF Power Output
Deviation Symmetry 5%
RF Output Impedance 50 ohms
Duty Cycle 50% (30 sec. Max transmit)
Adjacent Channel Power -70 dB
Intermodulation Attenuation -40 dB
Spurious and Harmonic FM -26 dBm max.
FM Hum and Noise 045 dB 25 kHz, -40 dB 12.5 kHz

±1.5 PPM (-30° C to +60° C)
MHz bands

2.5V DC ±1% temperature compensated to ±100 mV. Supplied in
Tx/Rx

1.8v P-P ±2dB produces ±5 kHz deviation with a 1 kHz tone
±2 dB, DC-5 kHz at 1 kHz (Programmable to ±0.5 dB with
diagnostic DAC
1-5W ±20% adjustable (5W at 13.3 V nominal

TABLE H-2. RF300 Radio Specifications - VHF

GENERAL

Frequency Range 132-150 MHz/150 - 174 MHz
Frequency Control Synthesized
Channel Spacing 15/30 kHz
Mode of Operation Simplex of Half Duplex
Operation Voltage +13.3V DC nominal (10 -16V DC operational)
Regulated Supply Voltages
Transmit Enable
Receive Enable
Transceiver Enable
Power and Data Connector 14-pin in-line Socket (Dupont 76308-14)
RF Input/Output Connector SMA Jack (female)
Operating Temperature
Storage Temperature
Humidity
Maximum Dimensions 4.585” L, 3.25” W, 2.212” H
FCC Compliance Part 90, Part 15
DM3412 Customer must apply

+5V DC ±5%
3-16V DC at 400 µA max
3-16 DC ± 5% at 400 µA nominal (400 µA during receive)
3-16V DC at less than 4000 µA

-30°C to +60°C

-40° C to + 85° C
95% maximum RH at 40° C, non-condensing

H-2

APPENDIX H. RF300 RADIO SPECIFICATIONS

RECEIVER

Bandwidth 132 - 15- MHz: 18 Mhz with electronic tuning, 6 MHz without

retuning from 132 - 150 MHz.
150 - 174 MHz: 24 MHz with electronic tuning, 6 MHz without

retuning from 150 - 174 MHz.
Frequency Stability
Sensitivity - 12 dB SINAD
RF Input Impedance 50 ohms
Selectivity -70 dB/-60 dB (tN/t/E) for 30 kHz, 60 dB/50db (tN/t/E) for 15 kHz
Spurious and Image Rejection -70 dB
Conducted Spurious Emissions <-57dBm
Intermodulation -70 dB
FM Hum and Noise -45 dB, 30 kHz channels psophometrically weighted

Receive Attack Time < 5 ms
Total Receive On Time 7 mS maximum
Audio
Distortion <3% psophometrically weighted
Buffered Output Level 150 mV RMS nominal at 2.5V DC bias
Discriminator Output +1/-3 dB from DC to 5 kHz (reference to 1 kHz)
Output Bias
Output impedance >10k Ohms
Data Characteristics 4800/9600 BPS NRZ
RSSI 0.75V to 2.0V DC output from -120 to -60 dBm, attack time < 2 ms

±2.5 PPM (-30° C to +60°C)

≤ 0.35 µV, -116 dBm psophometrically weighted

-40 dB, 15 kHz channels psophometrically weighted

2.5V DC ±20%

TRANSMITTER

Frequency Stability
Bandwidth 132 - 150 MHz, 18 MHz without tuning

Maximum System Deviation 5 kHz (30 kHz), 2.5 kHz (15 kHz)
Modulation FM/DC coupled
Input Bias

Input Impedance >40k
Distortion <3% at 60% of maximum system deviation, 1 kHz tone
Capability
Flatness

RF Power Output
Deviation Symmetry 5%
RF Output Impedance 50 ohms
Duty Cycle 50% (30 sec. Max transmit)
Adjacent Channel Power -70 dB
Intermodulation Attenuation -40 dB
Spurious and Harmonic FM -20 dBm max.
FM Hum and Noise 045 dB 30 kHz, -40 dB 15 kHz

±2.5 PPM (-30° C to +60° C)

150 - 174 MHz, 24 MHz without tuning

2.5V DC ±1% temperature compensated to ±100 mV. Supplied in

Tx/Rx

1.8v P-P ±2dB produces ±5 kHz deviation with a 1 kHz tone

±2 dB, DC-5 kHz at 1 kHz (Programmable to ±0.5 dB with

diagnostic DAC

1-5W ±20% adjustable (5W at 13.3 V nominal

H-3

APPENDIX H. RF300 RADIO SPECIFICATIONS

TABLE H-3. RF300 Radio Specifications - Loader Board

TRANSMIT

Transmit Current Adds no more than 27 mA to transceiver Transmit current.
Audio Response
Wide Band Input
DC Coupled +1/-3 dB from DC to 5 kHz (referenced to 1 kHz)
AC Coupled +1/-3 dB from 1 kHz to 5 kHz (referenced to 1 kHz)
Wide Band Output Bias
DC Coupled

AC Coupled
Narrow Band Input

FSK Input +1/-3 dB from 65 Hz to 2.5 kHz (referenced to 1 kHz) -30
Audio Input +1/-3 dB from 6 dB/octave pre-emphasis from 300-3000 Hz

Narrow Band Input Bias
FSK or Audio

Modulation Capability
Wide Band Input See transmitter specifications
Narrow Band Input

Audio Distortion <= 5% with 1 kHz tone at 60% maximum rated system deviation
Audio Input Impedance
Wide Band Input >= 40 k Ohms
Narrow Band Input >= 40 k Ohm or 600 Ohm, programmable

2.5V DC ±1% temp compensated to ±100 mV.(Must be supplied to
Tx/Rx)

2.5V DC ±1% temp compensated to ±100 mV.(supplied in Tx/Rx,
internally set)

dB/octave above 3 kHz
(referenced to 1 kHz (per TIA/EIA-603)) -42 dB/octave above 3

kHz.

2.5V DC ±1% temp compensated to ±100 mV.(supplied in Tx/Rx,
internally set)

Adjustable, factory preset for 60% ±10% maximum rated system
deviation with a 400 mV RMS, 1 kHz input.

RECEIVE

Current Drain Adds no more than 27 mA to transceiver receiver current
Carrier Detect
Attack Time Within 2ms of receiving an RF signal 20 dB greater than an RF

signal which produces at least 25 dB SINAD before squelching.
Dynamic Range 30 dB minimum -116 to -86 dBm
Audio Response
DC Coupled +1/-3 dB from DC to 5 kHz (referenced to 1 kHz)
AC Coupled +1/-3 dB from a 7 dB/octabe pre-emphasis curve from 300-3000

Hz referenced to 1 kHz (per TIA/EIA-603) - 18 dB/octave above 3

kHz
Output Load
Wide Band Output Load > 10k ohm
Narrow Band Output Load > or = 600 ohm
Output Level
Wide band Output
Narrow band Output

Distortion, Narrow/ Wide band
Output
Overload < or = to 10 % with RF input > or = to1 mV and < or = to 100 mV

100-200 mV RMS ±5% over voltage and temp variation

200-1600 mV RMS ± over voltage and temp variation at ±60%

max system dev, 1 kHz tone

< or = 5% with 1 mB RF input.

H-4

APPENDIX I. RF100/200 RADIOS

I.1 RADIO DESCRIPTION

The RF100 and RF200 are obsolete radios
used in Campbell Scientific's RF applications to
transmit and receive data blocks. The radios
are shipped from Campbell Scientific secured
on a mounting bracket designed to fasten on
the top of the RF modem (see Figure I-1). See
Appendix F for compatibility information.

The mounting bracket also supports a BNC
Jack connector from the radio. The coax cable
that is required to connect the radio to its
antenna should be connected to the radio at this
BNC connector. See Section 3.3 for more
information on the antenna cable.

The RF100/RF200 Radios are connected to the
RF modem by a special radio cable. The first
10-pin connector on this radio cable has a red
and black wire coming out of the connector.
This is the 10-pin connector (labeled "radio")
that should be connected to the radio. The red
and black power wires should be connected to
12 V and Ground respectfully. The second 10­pin connector (labeled "RF modem") should be
connected to the RF modem.

I.2 RADIO SPECIFICATIONS

The RF100/200 radios were manufactured by E.
F. Johnson. Campbell Scientific modifies the
radios to work with the RF95 Modem..

FIGURE I-1. RF100 On Bracket With Connector

TABLE I-1. Radio to RF Modem Pin Descriptions

RF100/RF200 RF95 RF
Radio 10-pin Modem 10-pin

17
23
3 +12V (Red) open (4)
46
58
69
72
85
9 GND (Black) open (10)

10 1

I-1

APPENDIX I. RF100/200 RADIOS

TABLE I-2. RF100/RF200 Radio Specifications

RF100 RF200

VHF UHF
E.F. Johnson Model No. 3420 3410
Power Output 4W 5W
Frequency (MHz)* 132-142, 142-150, 403-430, 430-450,

150-162, 162-174 450-470, 470-512
Channel Capability 1 1
Dimensions (w/o mounting) 3.6" x 2.9" x 2.2" 3.6" x 2.9" x 2.2"
Operating Temperature Range -30°C to +60°C -30°C to +60°C
Emissions Designator 16KOF2D 16KOF2D
Deviation ± 2.5 kHz ± 2.5 kHz
Current Drain
Quiescent 30mA 30mA
Active 1.7 A 1.5 A

* DOC Compliance for 138-174 MHz and 403-470 MHz only.

I-2

APPENDIX J. CABLE PIN OUTS AND LED FUNCTION

FOR RF95A AND RF300

TABLE J-1. Radio 10 Pin RF Connector

10 Pin
Radio Radio Description / Usage

1 Not used: TX Wideband (IN)
2 Not used: RX Wideband (OUT)
3 Not used: Frequency Select (IN)

Logic High = Freq. 1, GND = Freq. 2
4 Ground via pin 9
5 12VDC (IN)
6 Push To Talk [PTT] (IN) Logic High
7 Carrier Detect (OUT)
8 TX Data (IN)
9 Ground
10 RX Data (OUT)

TABLE J-3. Radio to RF95A Cable Pin Outs

10 Pin 10 Pin Extra
Radio RF Modem

1 8 Sleep Mode
2
3 3 Frequency Select (IN) Logic High.

4 6 TX Ground
5 N/C Red wire 12VDC (IN to Radio)
6 9 PTT Button Push To Talk [PTT] (IN To Radio From RF Modem)
7 2 Carrier Detect (OUT From Radio To RF Modem)
8 5 TX Data (IN To Radio From RF Modem)
9 2 Black wire Ground

10 1 RX Data (OUT)

Connections Description / Usage

PTT Button Return

TABLE J-2. RF95A 10 Pin RF Connector

10 Pin
Modem RF Modem Description / Usage

1 RXD (IN)
2 GND
3 Frequency Channel 1 or 2
4 Not used
5 TXD (OUT)
6 TXD Return
7 Not used
8 Sleep Mode
9 Receive/Transmit Control
10 Not used

FYI - All unused pins of the RF
Modem are connected to Ground
on the RF Modem.

No connection = Freq. 1; GND = Freq. 2

J-1

APPENDIX J. CABLE PIN OUTS AND LED FUNCTION FOR RF95A AND RF300

TABLE J-4. Radio 9 pin Serial

Communications Connector

9 Pin
Radio Description

1 Sleep/Wake Mode
2 RS-232 RX
3 RS-232 TX
4
5 Ground
6 Channel Select
7
8 Channel Select 1
9 Channel Select 2

LED’s

Yellow = Carrier Detect, indicates a carrier
frequency has been detected.

Green = Power applied to Loader, see below.
Red = Transmit, indicates the radio is

transmitting.

TABLE J-5. JDT Software

Items that can be set be the JDT Software and
the settings CSI will set the radios up for:

Radio Model: 3412 = UHF or 3422 = VHF
Range: See Chart

RX Audio Mode: FSK
TX Audio Model: Audio
600 Ohm input: On
Enable LEDs: On
PTT Polarity: Active Low
Carrier Detect Polarity: Active High
Sleep Mode Polarity: Active Low
RX Mute Control: Mute As Squelch
TX Only: No

Radios are factory configured with LED’s
enabled. When the radio is connected to
power, the Green power LED will stay on
unless the radio is connected to an RF95A and
a datalogger. When using the RF95A and
datalogger, the green LED will start flashing
after 45 seconds. A flashing green LED
indicates the RF300 is in sleep mode.

LED’s can be Enable/Disabled via the JDT
Software

J-2

GLOSSARY

Antenna - Device for radiating and receiving

radio signals.
Attenuation - The reduction of an electrical

signal without appreciable distortion.
Base Station - The destination for accumulated

data; where data is received via radio from one
or more field stations.

Baud Rate - A unit of data transmission speed,
normally equal to one bit per second.

Block - Group of ones and zeroes which
represent data or commands.

BNC Connector - A commonly used "twist
type" connector on radios.

Carrier Wave - A radio wave upon which the
signal is transmitted.

Coaxial Cable - An insulated RF transmission
line consisting of two conductors separated by a
dielectric.

COM Port (Communication Port) - The serial
port of the computer where communication is
intended.

Decibel - A unit of power equal to 10 times the
common logarithm of the ratio of two amounts
of signal power.

End of Link Modem - An RF modem which is
at the field station.

Field Station - The place of origin of the data,
from which the data is then transmitted by
radiotelemetry.

Megahertz - Cycles per second multiplied by
1,000,000.

Middle of Link Modem - Any modem in an RF
link which is not at the base station or the
designated field station.

Modem ID Number - A communication
identification number for an RF Modem, also an
aid in specifying the RF path.

Modulation - Process by which one waveform
(carrier) is caused to vary according to another
waveform (signal).

Omnidirectional - Capable of operating in all
directions.

Radio - Device which transmits and receives
electrical signals by means of radio waves.

Radio Frequency - The number of cycles per
second with which the carrier wave travels,
usually specified in Megahertz.

Radiotelemetry - Process of transmitting data
by radio communication.

Radiotelemetry Link - A temporary
communication path within a network.

Radiotelemetry Network - A group of stations
which communicate by radio and are used to
indicate or record data.

Reflected Power - Energy that is transferred
back into the radio after it has been transmitted
by the same radio.

Remote Site - See Field Station.

Forward Power - Energy that is transmitted

from a radio, through coaxial cable, and through
the antenna without being reflected back to the
radio.

Line of sight - Straight path between the
transmitting and receiving antenna when
unobstructed by the horizon.

Repeater - An intermediate station in an RF link
used for the sole purpose of relaying data.

RF - An abbreviation for radio frequency,
commonly used in place of radiotelemetry.

RF Modem - Device which modulates an
electrical signal on the carrier wave, and codes
all transmissions for a specific path.

a

GLOSSARY

RF Path - The designation of an RF link with

modem ID Numbers and modem commands.
RLQA (RF Link Quality Accumulators) -

Numbers which represent the quantity of
communication interruptions and the level of
communication noise.

Shutdown Block - Block of numbers which
contain the RF Link Quality Accumulators for
each modem in a terminated radiotelemetry
link.

Signal Power - Power of a signal at the
receiving radio, after power is lost through
transmission.

Start of Link Modem - The modem located at
the base station.

Squelch - Setting on the radio which specifies
the minimum power level which signals must be
received.

Sub Link - Any segment of an RF link which
begins and ends with an RF station.

Telecommunications Mode - A datalogger
status which enables communication from a
computer directly to the datalogger.

UHF (Ultra High Frequency) - Carrier
frequencies commonly in the range of 406 to
512 MHz.

VHF (Very High Frequency) - Carrier
frequencies commonly in the range of 130 to
174 MHz.

VSWR (Voltage Standing Wave Ratio) - The
ratio of the standing wave voltage across the
RF transmission cable at the high voltage points
to that at the low voltage points.

Unidirectional - Capable of operating only in a
single direction.

b

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