Intab PC-logger 3150 How To Use Manual

How to use

PC-logger 3150

Hardware

with

accessories

Interface-Teknik AB

Gjutarevägen 1

SE-443 61 STENKULLEN

Tel. [phone]

www.intab.se, [e-mail]

Rev. E, January 2003

ii

MANUALS

of the

PC-Logger 3150 System:

-"How to Use PC-Logger 3150 "

How to connect sensors and transducers
correctly

-"EasyView - manual"

A tutorial guide to a user-friendly expert
data analysis program

-"Command Manual"

Describes the ASCII strings (used by
software) that make the PC-Logger 3150
tick

iii

CONTENTS

MAIN UNIT......................................................................1

1 AN OVERVIEW ..............................................................................................................................1

1.1 G

ENERAL INFORMATION

................................................................................................................1

1.2 ON-

LINE RECORDINGS

....................................................................................................................2

1.3 OFF-

LINE RECORDINGS

..................................................................................................................2

1.4 S

TORAGE CAPACITY

.......................................................................................................................2

1.4.1 Storage capacity in Computer .............................................................................................3

1.4.2 Storage Capacity in the PC-Logger 3150............................................................................3

1.5 B

LOCK DIAGRAM

...........................................................................................................................4

1.6 D

ISPLAY AND KEYS (OPTION

).........................................................................................................5

1.6 P

OWER SUPPLY

...............................................................................................................................6

2 INPUTS/RANGES ...........................................................................................................................7

2.1 R

ANGES: VOLTAGE AND CURRENT

.................................................................................................8

3 CONNECTIONS..............................................................................................................................9

3.1 P

OWER

...........................................................................................................................................9

3.2 C

OMPUTER

.....................................................................................................................................9

3.3 I

NPUTS

.........................................................................................................................................10

3.3.1 Differential Inputs.............................................................................................................. 11

3.3.2 Common Mode...................................................................................................................12

3.4 S

ENSOR CONNECTION EXAMPLES

................................................................................................13

3.4.1 Connecting 20mA current loops ........................................................................................13

3.4.2 Connecting Voltage Signals............................................................................................... 15

3.5 C

OMMON CONNECTION ERRORS

...................................................................................................16

4 STARTING RECORDINGS.........................................................................................................19

4.1 S

TART TRIG

..................................................................................................................................19

4.1.1 Start on key-stroke ............................................................................................................. 19

4.1.2 Start on digital input..........................................................................................................20

4.1.3 Start on Analog Level ........................................................................................................20

4.1.4 Digital and Level Start combined ......................................................................................20

4.2 S

TOP TRIG

....................................................................................................................................20

4.2.1 Stop on key-stroke..............................................................................................................20

4.2.2 Stop on Digital Signal........................................................................................................21

4.2.3 Stop on Analog Level.........................................................................................................21

4.2.4 Stop when Memory Full.....................................................................................................21

4.3 T

RIG WINDOW - PRE/POST TRIG RECORDING

...............................................................................22

4.4 Illustration: Start, Stop and Trig Sequences...........................................................................23

4.5 T

RIG OUTPUT

...............................................................................................................................24

5 MISCELLANEOUS.......................................................................................................................25

5.1 M

ASTER RESET

............................................................................................................................25

5.2 C

ONTROL PROGRAM

....................................................................................................................25

6 TECHNICAL SPECIFICATIONS...............................................................................................26

6.1 ANALOG CIRCUITS.................................................................................................................26

6.2 A

UXILIARY VOLTAGE SOURCE

...................................................................................................... 27

6.3 T

RIGGER INPUT/OUTPUT

...............................................................................................................27

6.4 S

TORAGE MEMORY (OPTIONAL

).................................................................................................... 28

6.5 C

OMPUTER COMMUNICATION

....................................................................................................... 28

6.6 C

OMMANDS

..................................................................................................................................28

iv

CONTENTS

6.7 P

OWER

......................................................................................................................................... 29

6.8 M

ECHANICAL SPECIFICATIONS

..................................................................................................... 29

OPTION: Digital I/O and Pulse Counters......................31

1 OVERVIEW...................................................................................................................................31

1.1 D

IGITAL OUTPUTS

........................................................................................................................31

1.2 D

IGITAL INPUTS

...........................................................................................................................32

1.2.1 Opto isolated inputs........................................................................................................32

1.2.2 TTL-compatible inputs....................................................................................................32

2 COUNTERS ...................................................................................................................................33

2.1 R

ESET MODE

................................................................................................................................33

2.2 N

ORMAL MODE

............................................................................................................................33

3 CONNECTIONS............................................................................................................................34

3.1 D

IGITAL OUTPUTS

........................................................................................................................35

3.2 D

IGITAL INPUTS

...........................................................................................................................35

3.2.1 Opto Isolated ................................................................................................................... 36

3.2.2 TTL Compatible............................................................................................................... 36

4 TECHNICAL DATA..................................................................................................................... 37

4.1 D

IGITAL OUTPUTS

........................................................................................................................37

4.2 D

IGITAL INPUTS (@

25C +/-10C) ................................................................................................37

4.2.1 Opto Isolated Inputs........................................................................................................37

4.2.2 TTL-compatible inputs.................................................................................................... 37

4.3 A

UXILIARY POWER

......................................................................................................................38

4.3.1 for Opto-Couplers ........................................................................................................... 38

4.3.2 for TTL-Inputs.................................................................................................................. 38

INDEX........................................................................................39

1

MAIN UNIT

1 AN OVERVIEW

MAIN UNIT

1 AN OVERVIEW

1.1 General Information

The PC-Logger 3150 is a very versatile addition to our line of Analog to
ASCII Converters. It will cover the medium measuring rate range: up to a 1000
times per second.

Input ranges are +/-10V; +/-1000mV; +/-100mV; +/-50mV; 20mA.

Pulse counters are available as an optional add-on.

An PC-Logger 3150 together with software and a personal computer
constitutes a powerful data acquisition system.
The main use is off-line when an internal memory (optional) of the PC-Logger
3150 stores data for later transferral to computer.
On-line use is also possible but is limited by the performance of connected
computer. Max speed has to be determined by experiment.

Main features are :

• 8 analog inputs

• Programmable ranges on all inputs

• 12 bit ADC

• Off-line memory data storage (optional)

• Trigger input and output

• Auxiliary voltage output

• Programmable sampling interval: 1ms to 1000ms

• Fully compatible with all INTAB logger software

The scope of this manual is to enable the user to correctly connect sensors and
transducers and use the PC-Logger 3150 off-line.
How the PC-Logger 3150 is handled using our software and a PC is explained
in the program manual and by the program itself by its user-friendly and self­explanatory menus.

For best use and best results it is ABSOLUTELY essential that this
manual is studied in its entirety. Special emphasis should be put on
studying chapter 3 which describes how to connect transducers and other
signal sources.

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INTAB Interface-Teknik AB

1.2 On-line Recordings

On-line measurements are performed with the PC-Logger 3150 connected to
the computer's RS-232 port. Measurements can in this mode be monitored in
real-timeon the computer's display. The user must however be aware of the
speed-limitations set by the computer: don't expect it to handle more than eight
channels five times a second. If you are the fortunate owner of a faster
computer with a fast disk-drive you can probably go faster.
The user him/herself has to determine the maximum speed on his/her particular
computer.

1.3 Off-line Recordings

Off-line recordings are possible with loggers equipped with (optional) data
memory.

Off-line measurements should be preceded by the transferral of measurement
parameters from the computer to the PC-Logger 3150.
These parameters contain, among others (see program manual), information
about measurement interval and what channels that are to be active. They are
effective until a new set of parameters are downloaded. The PC-Logger 3150
can, after downloading of the parameters, be disconnected from the computer
and started with the help of the keys next to the LCD (see section 1.5). After
all measurements are completed (see stop : section 4.2) the PC-Logger 3150 is
again connected to a computer for transferral of collected data (X-fer).

1.4 Storage Capacity

The number of measurements that can be stored by the PC-Logger 3150 and/or
computer is dependent on the size and type of memory used.
The longest possible duration of a recording is a function of the number of
channels that are active, sampling rate and the size of the storage medium.

A discussion of how the maximum length of a recording can be calculated
from known parameters follows below.
It is assumed that recordings are made using software supplied by INTAB.

3

MAIN UNIT

1 AN OVERVIEW

1.4.1 Storage capacity in Computer

Storage capacity in your computer can readily be calculated. The amount of
free space on the disk that will store your measurement data is the limiting
factor.

A 3½" disk will store more than 1,400,000 bytes. This is sufficient to store a
total of 700 000 values.

If we now consider a case where you sample and store 5 channels per second
the following formula applies:
Measuring time = 700 000/5 = 140 000 seconds or almost 40 hours. This time
is naturally multiplied by five if you only use one channel.

Another example: this storage space can be two measurement rounds, each of
two channels every other millisecond for a total duration of 700 seconds (or
nearly twelve minutes).

The formula you use is: interval*storage capacity divided by 2 and the number
of active channels : I*S/(2*C).
Apply this to a hard disk, and you will find that storage space will last a very
long time.

Remember that total storage time in a disk is the sum of all recordings. You
just have to allow for a header space of 16k bytes.

1.4.2 Storage Capacity in the PC-Logger 3150

Storage capacity in the PC-Logger 3150 itself is calculated almost in the same
way as it is calculated in the on-line case.

Three sizes of memory can be supplied: 64k, 64k+512k or 64k+1M.
Every value stored uses two bytes, so the formula in the previous section can
be used here too.

An example: having 64k memory, you want to measure four channels 10
times every second. The interval is 0.1 seconds.
The formula will then be: 0.1*64,000/(2*4)=800 seconds.

Note:

The internal memory of the PC-Logger 3150 will only store one recording at a
time. Starting a new recording will erase the previous one.
Recordings have to be transferred to your computer before loading new
parameters or starting new measurements.

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INTAB Interface-Teknik AB

There is no limit to the number of times the same recording can be transferred
to the computer.
Measurement data will also not be lost if the internal batteries run down. A
back-up lithium battery will retain data for more than 10 years.

1.5 Block Diagram

This illustration shows a simplified block diagram of the PC-Logger 3150.
The expert notes that all amplification takes place before the multiplexer.

5

MAIN UNIT

1 AN OVERVIEW

1.6 Display and Keys (option)

The LCD (Liquid Crystal Display) with adjacent keys are supplied with all
PC-Logger 3150:s that are equipped with internal measurement data memory.
This display and key combination is indispensable when making off-line
recordings.
You indicate which function you want using the up/down arrows and then
confirm your choice with the OK-key.

The Multimeter is used to check transducer connections and function before
recording is started. You scroll up and down among the channels using the
up/down keys. Automatic scrolling is started with the key "hidden" under the
logo. A new channel is then shown every three seconds (try this feature by
pressing "PC-Logger 3100").

Record is selected when you intend to collect data. Verify your choice with
"OK". See illustration below and section 4 of this manual.

Starting a new recording will delete the previous one.
Don't forget to transfer data to the computer between recordings.

(*) See section 4 : TRIGGER.... for further information on starting and

stopping a recordings

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INTAB Interface-Teknik AB

1.6 Power supply

The PC-Logger 3150 is normally powered by the supplied mains adaptor. It
has an output of 13.5V at a max of 500mA.

The PC-Logger 3150 is also fitted with internal rechargeable batteries. They
will give the user at least one hour of recording time without mains supply.
The batteries are trickle charged when the mains adaptor is connected. There is
no danger of overcharging the batteries, they should be left on charge to
prolong their life and keep them ready to use at all times.

Some applications require the PC-Logger 3150 to be powered by other
sources.
Use a cable fitted with a TA3F (Switchcraft) connector to connect to, for
example, a car battery.
Don't use sources supplying more than 16V as this is the maximum allowed.

The PC-Logger 3150 will "fall asleep", if it isn't powered by an outside source,
about two minutes after the last command or key-stroke has been entered. This
feature saves your rechargeable batteries for when they are needed.
Incoming serial (RS-232) commands or pressing the C-key will wake the PC­Logger 3150.

7

MAIN UNIT

2 INPUTS/RANGES

2 INPUTS/RANGES

NOTE !
To get good results it is of utmost importance that all signals to be
measured are connected correctly.
Experience tells us that 95% of all problems (like noise, electrical
interference, measurement errors etc.) are the result of incorrect
connections and wiring.
A careful study of sections 2 and 3 is therefore highly recommended.

All analog inputs are differential and have no internal connection to signal
ground. The impedance between the positive and negative inputs to ground is
of the order of several megohms. They must therefore never be allowed to float
outside the specified common mode range, but must be referenced to ground in
some way.
The inputs are also balanced making them very unsusceptible to electrical
noise. Sensor wiring can be very long if a pair of twisted wires is used and the
ground reference is connected to the lowest potential of the signal source via a
separate wire.

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INTAB Interface-Teknik AB

2.1 Ranges: Voltage and Current

Each programmable (option) range or preset range has a resolution of at least
+/-1800 divisions.
Translated into measured units this can be illustrated like this:

RANGE RESOLUTION ACCURACY
+/-10V

+/-1000mV
+/-100mV
+/-50mV
+/-20mA

5.5mV

0.55mV

0.055mV
30µV
11µA

0.12% of FSR

0.12% of FSR

0.12% of FSR

0.12% of FSR

0.12% of FSR

Each channel has an internal 51Ω shunt that is used to measure current. It is
connected into the input circuitry by putting the small DIP-switch in position
"current".

9

MAIN UNIT

3 CONNECTIONS

3 CONNECTIONS

3.1 Power

Power is applied through a TA3F (Switchcraft) female connector connected as
follows :

Pin 1 :
Pin 2 :
Pin 3 :

13 - 16VDC
0V
18 - 24VDC

N.B. Connecting power through pin 3 is an alternative to pin 1 !

3.2 Computer

PC-Logger 3150 connects to a serial port of the computer using the supplied
spiral cable.
The 15 pin D-Sub connector has the following pinouts:
pin 2: Tx
pin 3: Rx
pin 5: CTS
pin 6: DTR
pin 7: GND
Leave the rest of the pins unconnected!

Typical PC-Logger 3150 to computer cables:

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INTAB Interface-Teknik AB

3.3 Inputs

Transducers and sensors connect to the detachable screw terminals.
Here is an illustration of how the screw terminals are placed.

These are analog channel inputs.
Behind each channel input terminal there is a pair of Dip­switches.
One (Volt/Current) connects the shunt resistor into the
input circuitry for current measurements (0 - 20mA).

The other (Diff/ Gnd) shorts the negative input to signal
(or reference) ground for single ended measurements.

This terminal (Gnd) is logger signal ground. All signals
must in some way be referenced to this point.

"+5V" is an auxiliary voltage for the Trig input (T-in).
"T-in" is a trigger input to start or stop recordings.
"G" is the signal return (ground) for trig-signals.
"T-out" is an output reflecting trig status.

"V-Out" is an auxiliary voltage for sensors or x-ducers.
Its voltage is adjustable between 2V and 10V by a
potentiometer.

These terminals are found under the lid of the logger. They are detachable.
Use the 16-hole bracket as strain-relief for transducer cables. You can use a
tie-wrap or simply thread the wire trough two holes.

NOTE!

These terminals are accessible also in those loggers that are equipped with an
optional jack panel. The jack panel must be regarded as just an extension box
and does NOT make familiarisation with the terminal area unnecessary.
The user still has to determine how the dip-switches are to be programmed.

11

MAIN UNIT

3 CONNECTIONS

3.3.1 Differential Inputs

There are a two basic requisites that have to be fulfilled when connecting
signals and/or sensors and transducers :
1 - No signal must be left floating with respect to logger signal ground.
2 - System grounds must be connected so that no ground loops are created.
Use a one-point grounding scheme!
The following sections will help in understanding how this can be achieved.

Let us first take a look at a block diagram of the inputs.

Differential channels (inputs) can be considered to be two different inputs:

• the - input measures the voltage between the GND and -

• the + input measures the voltage between the GND and +

The difference between these two voltages is then "calculated" internally.

From the above it must be obvious that just applying a voltage between - and +
cannot possibly work! The amplifier must see signals referenced to GND.
(GND, by the way, is an internal "signal ground" or reference that has nothing
in common with mains protective ground or any other ground that may be
lying around.)

If you have problems in understanding this, it is a good idea to tie the - input to
GND by putting the "Diff/Gnd" switch in position "Gnd". The result will be
that the channel will measure the voltage at the + input and then subtract the
voltage at the - input (which is zero volts) and present the correct value.

Just be sure that all your minuses have the same potential so that no
smoke signals are generated.

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INTAB Interface-Teknik AB

N.B.

In all work connecting signals to the logger you have to take the following
points into account :

• Analog ground is common to all channels.

• Analog ground is internally connected to RS-232 signal return (D-sub

pin 7).

• Analog ground is internally connected to power input return ( pin 2).

• Analog ground is internally connected to trig input and output signal

return ("G")

• Analog ground is internally connected to negative V-out.

3.3.2 Common Mode

To maintain accuracy in your measurements you have to take the common
mode range into account. The common mode range is 10V.
This is another way of looking at or taking advantage of the "differentiality" of
the inputs.

The impedances between "Gnd" and positive and "Gnd" and negative inputs
are very high. This means that unless they in some way are connected, the
inputs may float electrically, way beyond the allowed limit.
The inputs will not be damaged by voltages above this as long as they are
within 30V off signal ground.

The following sections of this manual will provide some examples of how
transducers can be connected.

13

MAIN UNIT

3 CONNECTIONS

3.4 Sensor Connection Examples

Transducers can supply signals of differing types. They are usually "single
ended" or "differential" (ratiometric). Below are some examples of how they
can be connected. Note that combinations are always possible.
It is also always good practise to plan connections and to make a schematic
diagram before actually doing them.

3.4.1 Connecting 20mA current loops

Currents are usually process type signals: 0-20mA or 4-20mA.
These loops can be connected in more ways than one.

It cannot be stressed enough that it is necessary to have a diagram of the
system from which these signals emanate in order to connect multiple
signals correctly.

Remember that the 51Ω shunt resistor has to be connected to the input

circuitry by putting the Dip-switch in position "current". See illustrations
below.

1) Connecting current loops with common grounding :

One connection to
the common ground
potential is enough.

Two would have
created a ground
loop that may cause
problems in the
form of electrical

interference.
"Other instruments" may also be connected in the current return path if it is
absolutely certain that the total voltage drop across them is well within max
common mode range.

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INTAB Interface-Teknik AB

2) Connecting floating (ungrounded) current loops

All signals have to
be referenced to
"Gnd".
They may otherwise
drift outside the
common mode
range.

3) Connecting two-wire mA transmitters using power from V-out.

The auxiliary Voltage output
(V-out) can power 20mA
transmitters.
Make sure that the voltage is
sufficient for your x-mitter.

4) Connecting two-wire mA transmitters powered by external source.

Transmitters that require
higher voltages have to be
powered by an external
source.
Don't forget to put the dip­switch in position "Gnd"
unless this source has some
other connection to logger
ground.

15

MAIN UNIT

3 CONNECTIONS

3.4.2 Connecting Voltage Signals

Voltage signals can be connected in two basic ways. Which one to use depends
on whether the signal is "floating" or not.

Combinations of the two methods are of course possible!

Differential or ratiometric transducers may also be directly connected.

1) Connecting signals with common grounding

Note that only one of the
Diff/Gnd switches is in
position "Gnd".
This will establish a
good reference potential
for both channels.

2) Connecting isolated or "floating" signals.

Each floating signal has
to be individually
grounded to logger
"Gnd".

3) Differential or Ratiometric transducers

This illustration shows
how a bridge type
transducer (load cells,
pressure sensors etc.)
should be connected.
The "V-out" is used as
excitation voltage.

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INTAB Interface-Teknik AB

3.5 Common connection errors

1) Ground loops:

Instrument with two Single Ended Outputs

Two apparently separate outputs from an instrument are each connected to a
channel. Both channels have the negative input shorted to ground via the
"Diff/Gnd"-switches.
Measured values may be either unstable or inaccurate.
Solution: break the ground loop by putting one of the switches in the "Diff"
position.

2) Floating signal : no connection to system ground

A signal equivalent to a common flashlight battery is connected to + and - of
one of the channels. Readings are unstable.
Solution: give this signal a proper ground reference by shorting the negative
input to logger ground by placing the Dip-switch in the "Gnd" position.

17

MAIN UNIT

3 CONNECTIONS

3) Common mode voltage too high.

In many industrial applications, the signal from one mA transmitter may be
monitored by several instruments. These are always connected in series. If the
total series resistance of these instruments causes a voltage drop of more than
10V AND if it appears on the ground side of the logger, the common mode
range is exceeded. This will cause the input amplifier to saturate resulting in
inaccurate readings.
Solution 1 : move other instruments to positive side of channel.
Solution 2 : use isolation amplifiers.

4) Absurd value when measuring in current loop ( defect x-mitter? )

The logger shows an absurdly high value and the x-mitter seems to be defect.
This will be the result if the "Volt/Current" switch has been left in the Volt
position.
The x-mitter will try to output its current through the high impedance of a
voltage input instead of the 50Ω of the current shunt. It will consequently
output as much Voltage as it can, again making the input amplifiers saturate.
Solution : put the Dip-switch in the "Current" position.

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INTAB Interface-Teknik AB

5) Bridge connection error

The illustration shows how one leg of a bridge type transducer ( f. ex. load cell
or pressure transducer) may be shorted by mistake.
The V-out negative terminal is internally connected to logger ground. By
connecting the negative input by placing the switch in the "Gnd" position one
of the resistors in the bridge is effectively shorted.
Solution : place the switch in the "Diff" position.

19

MAIN UNIT

4 STARTING RECORDINGS

4 STARTING RECORDINGS

As you have seen in the previous sections, there are two ways of recording
data: on-line and off-line.
Programs supplied with the PC-Logger 3150, guide the user through the set-up
procedures necessary before recordings can be started.

On-Line Recordings are initiated from the computer.
Data is then continuously transferred via the RS-232 interface and stored on
disk.
The user must however be aware of the limited speed at which data can be
acquired in this mode (see 1.1).
This mode is explained in detail in the software manual. The rest of this
section will therefore deal exclusively with off-line recordings.

Off-line recordings are prepared by setting the appropriate parameters with
the help of the supplied software (see program manual).
Start and Stop parameters are particular to the "f"-version of the PC-Logger

3150. How they work is explained below.
Start and Stop levels are programmed in the "Activate channels" part of the
program. Access to this facility is gained in the "TRIG" column.
Don't forget to switch these levels ON after you have programmed them.
Start and Stop parameters are activated in the "parameter" part of the software.

4.1 Start Trig

There are four different factors that may start the PC-Logger 3150 recording
after "Start Recording" has been okayed by the operator:
1 - Another "OK" key-stroke or
2 - A logical high at the trig input or
3 - An analog signal outside a programmed level or
4 - A logical high at the trig input followed by an analog signal
outside a programmed level

4.1.1 Start on key-stroke

Use the keys next to the LCD and "OK" all steps up to the point where it says
RECORDING: READY FOR STOP.
It will now record with set sampling interval until a stop condition is met.

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INTAB Interface-Teknik AB

4.1.2 Start on digital input

A digital signal may be connected to the trig input. A high level will start the
recording if the LCD shows "STANDBY ... READY TO START".

A "high level" is a voltage above 4V.

The digital input source may be either a TTL/CMOS signal or a simple contact
closure. Be sure to get your wiring correct and note that the GND is the same
point as the analog GND. (See section 3 for implications)

4.1.3 Start on Analog Level

A recording may also be started by an analog signal being outside a
programmed level or "window".
Levels may be programmed so that a recording will be started when a signal
either goes above a set level or under another set level.
If these two levels are set to -2V and +3V respectively, the recording will not
start as long as the signal is inside this range. A signal below -2V or above 3V
will start the recording.

4.1.4 Digital and Level Start combined

Both the digital and level methods may be used in one recording. The logger
will first monitor the digital input for a trig condition. When it occurs it will
monitor analog inputs for levels outside set levels. When trig levels are
detected the recording starts.
In other words : both trig conditions must be met before recording starts.

4.2 Stop Trig

There are four ways of stopping a recording:
1 - A key-stroke or
2 - A logical low at the trig input or
3 - An analog signal outside a programmed level or
4 - Memory full

4.2.1 Stop on key-stroke
Any key-stroke will always stop a recording.

21

MAIN UNIT

4 STARTING RECORDINGS

4.2.2 Stop on Digital Signal

Recording parameters can be programmed so that a recording will stop as soon
as the digital input detects a "low". A "low" is a voltage below 0.8V!.
An "open" digital input is held low by an internal resistor.

4.2.3 Stop on Analog Level

Recordings may be programmed to stop on a signal outside a programmed
level.
An example may be in place:
A voltage being monitored should vary between 4V and 8V. Any value below
4V or above 8V indicates a malfunctioning. The recording should stop after
such an event so that data can be transferred to computer for analysis.
"Stop on level trigs" must then be programmed to 4V and 8V as the lower and
upper levels.

4.2.4 Stop when Memory Full.

Recording will automatically stop when the memory is full.

Unless of course endless or circulating memory is programmed, in which case
the memory will "wrap around" and only stop on key stroke or stop trig.

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INTAB Interface-Teknik AB

4.3 Trig Window - Pre/Post Trig Recording

The PC-Logger 3150 is often used as a trouble-shooter to catch transient
events. The area of interest is often the time just prior to the fault condition and
then a certain amount after.
The fault condition would trigger the stop.
The time before (pre) and after (post) this event constitute the "Trig Window".

Windows are programmed as a parameter in the "/RECORD/PARAMETERS/"
section of the "PC-Logger 3100 PC soft". It requires "circulating" memory
which is consequently automatically switched on.
The window is programmed as a pre-trig time and a total time. The post-trig
time will of course be the difference between the total and pre-trig time.

The recording, started with the trig-window active, will first go through a "pre­amble", corresponding to the pre-trig period, when it is insensitive to stop
trigs. After the pre trig period it will register a stop-trig when it occurs and
then continue for the post-trig period before stopping.

The recording can be left to run for very long periods thanks to the
"circulating" or endless memory. The window with correct time will just "slide
along" and always be there for transferral after the stop-trig and post trig
period.

The entire recording can, of course, be transferred to computer. It is, however,
usually more practical to just transfer the window. The software will give you
the choice!
When the transferred "window" is presented as graphs, a vertical line
indicating where the stop-trig occurred, is shown on the computer screen.

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4 STARTING RECORDINGS

4.4 Illustration: Start, Stop and Trig Sequences

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4.5 Trig Output

Several "F" loggers can be "synchronised" by interconnecting them via the trig
output.
The trig output goes high reflecting start trig status. It will go low to indicate
that a stop trig condition has occurred.
By connecting this output to the digital trig input of another "F" and using
these properties it is possible to start the recording of two loggers
simultaneously.

Logger 1 will trig Logger 2 as soon as it starts (or stops) storing values.
Logger 2 has to be programmed to start and/or stop on a trig from the digital
trig input.

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MAIN UNIT

5 MISCELLANEOUS

5 MISCELLANEOUS

As is implied by the topic, this section is intended for information that is not
readily covered by the other sections of this manual. The information is,
however, considered important or interesting enough to be included.

5.1 Master Reset

A master reset of the PC-Logger 3150 can be performed by temporarily
shorting pins 7 and 8 of the 15 pin D-Sub connector. A master reset will erase
the internal program of the PC-Logger 3150. You will then have to re-boot the
program from your computer. Make sure that you have the correct version of
the PC-Logger 3150 program installed (the name of the bootable file is
BFA_????.LDM ). where ???? is a version number.

Front view of the D-Sub PC-connector

5.2 Control Program

The program that controls the PC-Logger 3150 is stored in Random Access
Memories in the PC-Logger 3150 itself. This makes it possible to modify the
way the PC-Logger 3150 operates by simply downloading (or booting) a new
program.

Those users who write their own computer programs to operate the PC-Logger
3150, are recommended to study the separate "command manual" and the
BOOT command.

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6 TECHNICAL SPECIFICATIONS

6.1 ANALOG CIRCUITS

Measuring method :

Successive approximation
11 bits + sign

Measurement interval :

Off-line :

Min 1 ms per channel.
Max 1000ms

On-line :

Min NA
Max 1000ms

Inputs : 8 differential inputs

Impedance:

Max overvoltage :
Max overcurrent :
(20mA range)

min 400kΩ betw. + and ­min 5MΩ betw. + and GND
and betw. - and GND
Current inputs are shunted by
51Ω

30V

80mA

Ranges :
(Factory set or
programmable)

Voltages :

Current :

+/- 50mV
+/- 100mV
+/- 1000mV
+/- 10V

+/- 20mA

Dynamic range :
(No of divisions)

Min. +/- 1800 divs. on all ranges

Resultant resolution : 50mV range

100mV range
1000mV range
10V range

20mA range

+/-30µV
+/-55µV
+/-0.55mV
+/-5.5mV

+/-11µA

Uncertainty : @ 25°C
(all ranges)

0.25% of FSR

Tempco : 100ppm + offset drift

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6 TECHNICAL SPECIFICATIONS

Offset: (@ 25°C)

Initial :
Drift :
50mV range
100mV range
1000mV range
10V range

20mA range

+/-½ division (=bit)

72ppm/°C
36ppm/°C

3.6ppm/°C

0.4ppm/°C

3.6ppm/°C

Common mode range

at the:

CMRR (DC)

50mV range
100mV range
1000mV range
10V range

20mA range

all ranges

+/-10V
+/-10V
+/-10V
+/-5V

+/-10V

min. 80dB

6.2 Auxiliary voltage source

Voltage :

Current :

2 - 10V adjustable
Max 100mA using supplied PSU
Max 200mA using PSU with higher power rating

6.3 Trigger input/output

Trigger input

Trigger output

HC-CMOS Schmitt trigger input with 100kΩ
series resistor and 100kΩ pulldown.

HC-CMOS output. Low < 0.1V (Io> -4mA)
High > 4.7V (Io< +4mA)

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6.4 Storage memory (optional)

Sizes :

0k bytes (only on-line usage)
64k bytes
544k bytes
1046k bytes

Every stored measurement value

occupies two bytes.

6.5 Computer communication

Data is transferred in a serial form to and from the computer. The serial
standard conforms to a subset of RS-232.

Format :

8 bit ASCII
1 start bit
8 data bits
1 stop bit
19200 baud

Signals :

Tx (2)
(pin no.) Rx (3)
CTS (5)
DTR (6)
GND (7)

Handshaking :

Hardware handshaking is employed.
DTR : Signals that the logger is operational

(output)
CTS : Signal allowing the logger to transmit

(input)

6.6 Commands

See separate manual: "Command manual".

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6 TECHNICAL SPECIFICATIONS

6.7 Power

Voltage 13 - 16 VDC
Operating current Max 500 mA

6.8 Mechanical specifications

(Example)

Width : 165 mm
Length : 315 mm
Height : 50 mm
Weight : 1.7 Kg

31

OPTION: Digital I/O and Pulse Counters

1 OVERVIEW

OPTION: Digital I/O and Pulse Counters

1 OVERVIEW

The PC-Logger 3150 can, in addition to the analog inputs, be fitted with a
digital I/O-interface.
This digital board is mainly used in event-counting applications but can also be
used where status or on/off signals must be detected.

The relay outputs of the PC-Logger 3150 are not supported by existing
software.

This card is available in two versions: with or without counters.

A fully equipped card has the following I/O's:

- 4 digital outputs (relays)

- 8 digital inputs, 6 of which can be used as inputs to the
counters.

1.1 Digital Outputs

Four digital outputs in the form of (relay) contact closures are available. They
find their use as alarms and in simple regulating functions and, in the case of
the "f", are as such not supported by the software.

The relay coils are, to prolong battery life, powered directly by the mains
adapter and not by the internal batteries.

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1.2 Digital Inputs

Eight digital inputs are available. Input status of these can be monitored by the
computer.
This way you can measure analog signals and at the same time make sure that
digital (on/off) control signals assume the correct level at the right time.

Six event counters can be paralleled with these inputs.
By connecting pulse type transducers (flowmeters are often of this type) to
these inputs you will get values that represent pulses/time interval. This is the
easily transformed into litres per second.
The PC-Logger 3150 software can be said to be treating these values as if they
were ordinary analog values or voltages.

The digital inputs are on request fitted with filters for electrically noisy
environments.

1.2.1 Opto isolated inputs

The Opto isolated inputs (DI1 - DI8) are used to detect high-level (>10V)
signals or where isolation is essential.

The a and b inputs are equivalent and insensitive to reversal of polarity.

The auxiliary output (VO) will power the opto-couplers if no external source is
available (see 3.2.1). This output is connected directly to the mains adaptor and
is unfused. Make sure you have connected it if you want to use this output.
Remember also that you lose isolation when you use VO.

1.2.2 TTL-compatible inputs.

TTL- or low-level signals are connected to the so called pulse inputs (P1-P6).
These are paralleled with the corresponding DO inputs and do not provide any
isolation to the measured/monitored object.
The auxiliary power output for these inputs is Vp.
This voltage is derived from the internal battery through a current limiting
resistor

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OPTION: Digital I/O and Pulse Counters

2 COUNTERS

2 COUNTERS

The digital I/O card can be fitted with six sixteen bit counters. Each of these
counts up to 65535 and then wraps around to zero.
They can be read with constant time intervals resulting in measurements values
representing pulses per delta-t.

Flowmeters output a set number of pulses per given unit of volume. They are
therefore an excellent example of how the counters can be used to measure
flow.

2.1 Reset mode

Reset mode will reset (or zero) the counters as soon as their value is taken care
of. This value is then treated as if it were an ordinary analog measurement.
(Litres per second maybe ?)

2.2 Normal mode

Normal (or accumulating) mode does not reset the counters when they have
been read. Values that are taken with this mode are in fact the time-integral of
the transducer output.
This mode is not supported by the software. See the command manual for
further information on this mode.

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3 CONNECTIONS

Connections are made to the screw terminals under the lid of the PC-Logger

3150. Note that VO is unfused and should not be loaded more than the mains
adaptor is able to supply and never more than 500mA.

Terminal configuration is shown in the illustration below.

DI 8b

DI 8a

DO 4b

DO 4a

DO 3b

DO 3a

DO 2b

DO 2a

DI 7b

DI 7a

DI 6b

DI 6a

DI 5b

DI 5a

DO 1b

DO 1a

GND

GND

P6

P5

VO

GND

DI 4b

DI 4a

DI 2b

DI 2a

DI 3b

DI 3a

P2

P1

P4

P3

Vp

Vp

DI 1b

DI 1a

DO = Digital Output
DI = Digital Input
P = Pulse Input
Vo = Auxiliary Power (for DI)
Vp = Auxiliary Power (for P)

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OPTION: Digital I/O and Pulse Counters

3 CONNECTIONS

3.1 Digital outputs

The digital outputs are in the form of four normally open relays.
These potential free contacts are accessible on DO1a,b - DO4a,b; see figure.

RELAY SPST

DO a

DO b

Switching Capability:
Power - 30W/50VA
Voltage - 125V AC/150V DC
Current - 1.25A AC/DC

3.2 Digital inputs

The figure below shows how the TTL and opto-isolated inputs are
interconnected.

FILTER

OPTO
ISOL.

RECTI­FIER

DI a

DI b

Px

FILTER

1
2

3

To µ-Processor

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3.2.1 Opto Isolated

The opto-isolated digital inputs can be used in two ways. Which method you
use depends on your particular application.
See figure!
The transducer marked "PULSE" has to be able to drive the input:
see 4.2.1 for levels and frequencies.
Remember that mechanical contacts always bounce when brought together.
This bouncing will, unless filtered, result in a burst rather than one pulse.

VO

GND

OR

DI b

DI a

PULSE

MAX 24V

OPTO ISOLATION
ANY POLARITY

DI a

DI b

3.2.2 TTL Compatible

The TTL-compatible inputs (P = Pulse in) are connected as in the figure.
Note that signal ground (GND) of the digital card has to be connected to signal
ground of the system or transducer that is used with these inputs.

GND

GND

1 2

TTL/CMOS

P1

P2

Vp

Vp

AND/OR

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OPTION: Digital I/O and Pulse Counters

4 TECHNICAL DATA

4 TECHNICAL DATA

4.1 Digital Outputs

No of outputs : 4
Type : Potential-free relay contacts (NO, SPST)
Switching
capability

Power
Voltage
Current
Max operating
current

: 30W/50VA
: 125VAC/150VDC
: 125VAC/150VDC
: 1A @ 60°C

4.2 Digital Inputs (@ 25C +/-10C)

4.2.1 Opto Isolated Inputs

No of inputs
"Low" level
"High" level
Max input voltage
Impedance
Input current
Max frequency

: 8
: Max 4V
: Min 8V
: 30V
: Min 1k Ohms
: Max 30mA at 30V in
: Min 30kHz at duty cycle 50%

4.2.2 TTL-compatible inputs

No of inputs
"Low" level
"High" level
Max input voltage
Impedance
Input current
Max frequency

Min pulse width

: 6
: Max 1.5V
: Min 3.5V
: 20V
: Min 50k Ohms
: Max 30mA at 30V in
: Min 70kHz at 5V and duty cycle=50%
: Min 30kHz at 10V and duty cycle=50%
: Min 20kHz at 15V and duty cycle=50%
: Max 15µs

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4.3 Auxiliary Power

4.3.1 for Opto-Couplers

Voltage : mains adaptor output, max 15V.
Current : mains adaptor rating -300mA or max 200mA

4.3.2 for TTL-Inputs

Voltage : 4-6V
Impedance : 1kΩ

39

INDEX

INDEX

A

Analog ground, 13

auxiliary voltage, 10

B

batteries, 4
block diagram, 4
BOOT, 26
bridge, 16

C

car battery, 6
channel input, 10
circulating memory, 22
C-key, 6
collect data, 5
common mode, 13
Common mode, 28
counters, 31, 32
CTS, 9
current, 8
current loops, 14

D

data memory, 2, 5
detachable, 10
Diff/ Gnd, 10
Diff/Gnd, 12, 16

difference, 12
Differential, 12

Differential Inputs, 11
digital I/O-interface, 31
digital inputs, 32
DIP-switch, 8

dip-switches, 11
DTR, 9
duration, 2

E

endless, 22
endless memory, 23
event counters, 32
event-counting, 31
excitation voltage, 16
extension box, 11

F

fall asleep, 6
float, 13
floating signal, 16
Floating signal, 17
flowmeters, 32

G

G, 10
Gnd, 10, 12

GND, 9

Ground loops, 17

H

header space, 3

I

impedances, 13
input, 10
Input ranges, 1
internal batteries, 4

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J

jack panel, 11

K

keys, 20

L

LCD, 5
lid, 10
load cells, 16
logo, 5

M

mains supply, 6
master reset, 26
memory, 3

Multimeter, 5

O

off-line, 1
Off-line, 2
off-line recordings, 5

Offset, 28
OK-key, 5

On-line, 1, 2
Opto isolated inputs, 32

P

post-trig, 23
Power, 9
power input return, 13
Power supply, 6
powered, 6
Pre/Post Trig, 23
pressure sensors, 16
pre-trig, 23
pulse, 32
Pulse counters, 1

R

range, 8
ratiometric, 14
ratiometric transducers, 16
READY FOR STOP, 20
real-time, 2
re-boot, 26
rechargeable batteries, 6
Record, 5
relay, 31
resolution, 8, 27
RS-232, 2
Rx, 9

S

schematic diagram, 14
screw terminals, 10
serial port, 9
shunt resistor, 10
single ended, 10
speed-limitations, 2
spiral cable, 9
Start, 20
Start on Analog Level, 21
Start on digital input, 21
Start on key-stroke, 20
Start Trig, 20
STARTING RECORDINGS, 20
Stop, 20
Stop on Analog Level, 22
Stop on Digital Signal, 22
Stop on key-stroke, 21
Stop Trig, 21
Stop when Memory Full, 22
storage capacity, 3
strain-relief, 10
Successive approximation, 27

T

T-in, 10

total duration, 3
T-out, 10

41

transducer connections, 5
transmitter, 18
transmitters, 15
trickle charged, 6
trig output, 25
Trig Window, 23
TTL-compatible inputs, 36
Tx, 9

U

Uncertainty, 28

W

window, 23
Volt/Current, 10
Voltage signals, 16

V-out, 13
V-Out, 10

wrap around, 22

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