dataTaker - Data Loggers, Powerful and Flexible Data Acquisition & Data Logging Systems

The Analog Input Channels

The dataTaker analog input channels are used for measuring a large variety of analog signals from sensors, transducers, instruments, etc. The dataTaker models have a different number of analog input channels as follows

dataTaker 50                                       5 differential, 10 single ended analog channels
dataTaker 500/600 series loggers           10 differential, 30 single ended analog channels
Channel Expansion Module (CEM            10 differential, 30 single ended analog channels

The dataTakers and the Channel Expansion Modules also have several internal analog channels, which are used for monitoring calibration references, and case temperature. These channels are not available for measurement of external signals, but can be read in the same manner as the analog input channels.

The allocation of analog input channels for each of the models of the dataTaker and the Channel Expansion Module are summarised in the sections below.

Analog Channels of the dataTaker 50

The dataTaker 50 has 7 analog input channels, which are allocated between external user channels and internal reference channels as follows

Channels 1 to 5                ñ user analog input channels
                                     ñ differential and single ended modes

Channel 1%                     ñ dataTaker 50 case temperature
                                     ñ LM35 solid state temperature sensor
                                     ñ cold junction temperature ref for thermocouples
                                     ñ read as channel 1%LM35

Channel 2%                     ñ zero voltage, and 100.0 Ohm resistance reference
                                     ñ 100.0 Ohm resistance, grounded
                                     ñ zero voltage reference for thermocouple compensation
                                     ñ read as channel 2%V for zero voltage
                                     ñ read as channel 2%R for 100.0 Ohm reference

Analog Channels of the dataTaker 500/600 Series

The dataTaker 500/600 series loggers have 12 analog input channels, which are allocated between external user channels and internal reference channels as follows

Channels 1 to 10               ñ user analog input channels
                                     ñ differential and single ended modes

Channel 1%                     ñ dataTaker 500/600 case temperature
                                     ñ LM35 solid state temperature sensor
                                     ñ cold junction temperature reference for thermocouples
                                     ñ read as channel 1%LM35

Channel 2%                     ñ Internal zero voltage, and 100.0 Ohm resistance reference
                                     ñ 100.0 Ohm resistance, grounded
                                     ñ zero voltage reference for thermocouple compensation
                                     ñ read as channel 2%V for zero voltage
                                     ñ read as channel 2%R for 100.0Ω reference

Analog Channels of the Channel Expansion Modules

The Channel Expansion Module (CEM-AD) has 12 analog input channels which are allocated as follows

Channels n:1 to 10            ñ user analog input channels
                                     ñ differential and single ended modes

Channel n:1%                   ñ CEM case temperature
                                     ñ LM35 solid state temperature sensor
                                     ñ cold junction temperature reference for thermocouples
                                     ñ read as channel n:1%LM35

Channel n:2%                   ñ internal zero voltage
                                     ñ zero voltage reference for thermocouple compensation
                                     ñ read as channel n:2%V for zero voltage

where n is the Channel Expansion Module number. The analog input channels of the Channel Expansion Module are implemented in same way as those of the dataTaker.

Differential and Single Ended Analog Inputs

The analog input channels of the dataTaker and Channel Expansion Modules can be used for measuring differential inputs and single ended inputs. The differential and single ended input modes can be mixed within an application. Details for connecting analog signals as differential inputs and as single ended inputs are given in Section II.

Differential Analog Inputs

Differential inputs are applied between the positive terminal and the negative terminal of each of the analog input channels. The dataTaker 50 can accept up to 5 differential inputs, while the dataTaker 500/600 series can accept up to 10 differential inputs. Details for connecting analog signals as differential inputs are given in Section II.

Differential analog inputs are specified by nominating the channel number and signal type as the following examples illustrate

3V                  voltage between + and - terminals of channel 3
8TK                thermocouple K between + and - of channel 8
1:2I               current between + and - terminals of channel 2 of CEM 1

Using DeTransfer, differential analog inputs are specified if the channel number has no analog terminal specified, as shown in the examples

3V
8TK
1:2L

Using DeLogger, differential analog inputs are selected from the dialog which opens for the selected signal or sensor group, for example

 

Single Ended Analog Inputs

Single ended inputs are applied to the analog input channels in several different configurations

between the positive terminal + and Analog Return terminal R

between the positive terminal + and the SE REF terminal

between the negative terminal ñ and Analog Return terminal R

between the negative terminal ñ and the SE REF terminal

between the Excite terminal T and the Analog Return terminal R or the SE REF terminal. This mode is not appropriate for resistance or RTD inputs, and is not available in the dataTaker 50

between the Analog Return terminal R and any Ground terminal G for current, current loop and AD590 types only

The single ended inputs between the +ve, ñve or T terminals and the SE REF terminal are actually measured differentially by the dataTaker.

However, these input configurations are referred to as single ended input modes, as distinct from the true differential input mode.

Single ended analog inputs are specified by nominating the channel number and the terminal for the positive lead of the signal, and the signal type as the following examples illustrate

3+V                    voltage between + and R terminals of channel 3
8ñTK                  thermocouple K between ñ and R of channel 8
2:7+I                current between + and R terminals of channel 7 of CEM 2

Using DeTransfer, single ended analog inputs are specified if the channel number includes an analog terminal which is the nominal positive side of the signal, as shown in the examples

3+V
8-TK
2:7+I

Using DeLogger, single ended analog inputs are selected from the dialog, which opens for the selected signal or sensor group, for example

 

 

Single Ended Inputs for the dataTaker 50

These single ended analog input arrangements provide a for a total number of single ended channels for the dataTaker 50 as follows

15 single ended input channels for measuring current, 4-20 mA current loop and AD590 temperature sensors

10 single ended input channels for measuring resistance and RTDs

10 single ended input channels for measuring all other analog signal and sensor types.

Details for connecting analog signals to the dataTaker 50 as single ended inputs are given throughout Section II.

Single Ended Inputs for the dataTaker 500/600 Series

These single ended input arrangements provide a total number of single ended channels for the dataTaker 500/600 series loggers as follows

40 single ended input channels for measuring current, 4-20 mA current loop and AD590 temperature sensors

20 single ended input channels for measuring resistance and RTDs

30 single ended input channels for measuring all other analog signal and sensor types.

Details for connecting analog signals to dataTaker 500/600 series loggers as single ended inputs are given throughout Section II.

Analog Input Types

The different types of analog signals and sensors that are supported by the dataTaker are described in detail in Section II of this manual.

Each of the signals and sensors supported are specified in schedule lists using input signal type or sensor type identifiers. These type identifiers generally are abbreviations of the actual signal or sensor name.

The type identifiers, channel capacity, connection configurations, default channel options and other details for the various analog signal and sensor types supported by the dataTaker are detailed in the table overleaf.

 


Analog Input Types

 

Signal Category

Signal or Sensor Details

Channel Type Label

Example

Channel Options

Channel Factor

Resolution

Units

Voltage

Voltage, ±25mV, ±250mV, ±2500mV

V

1V

(1.0,T*)

attenuation factor

1 microV

mV

 

High Voltage, ±7V, ±70V, ±100V,

HV

2HV

(1.0,A)

attenuation factor

250 microV

V

Current

Current, internal 100Ohm shunt, or external shunt

I

3#I

(100.0,T*)
(100.0,A)

shunt resistance
(ohms)

10 nA

mA

 

4-20 mA current loop

L

5#L

(100.0,T*)

shunt resistance
(ohms)

0.01%

Percent

Resistance

Resistance by 2, 3, 4 wire methods, 7KOhm max

R

4R(II)

(1.0,I)

scale factor

1 mOhm

Ohms

Bridge

Quarter, half, full bridge, 3 & 4 wire, current excitation

BGI

1BGI(60)

(350.0,II)

arm resistance
(ohms)

1 ppm

ppm

 

Ratiometric, 4 & 6 wire bridges, voltage excitation

BGV

3BGV

(0.0,V,4W)

offset
(ppm)

0.1 ppm

ppm

Frequency

Freguency, 0.102Hz to 20KHz

F

2F

(30.0,T*)

longest period
(mSec)

0.01 Hz

Hz

 

Period, 50uSec to 9.8 sec

P

7+P

(30.0,T*)

longest period
(mSec)

1 mSec

uS

 

Vibrating wire sensor, frequency

FW

6FW

(ES9,200.0)

delay
(mSec)

0.1°C

DegC*

Temperature

Thermocouples B, C, D, E, G, J, K, N, R, S, T

TB, TC, TD, TE, TG, TJ, TK, TN, TR, TS, TT

3TK

(1.0,T*)

attenuation factor

0.1°C

DegC*

 

Platinum RTD, a=0.00385, 0.003916

PT385, PT392

1PT385

(100.0,II)

resistance at 0°C

0.1°C

DegC*

 

Nickel RTD, a=0.005001

NI

4NI

(1000.0,II)

resistance at 0°C

0.1°C

DegC*

 

Copper RTD, a=0.0039

CU

9CU

(100.0,II)

resistance at 0°C

0.1°C

DegC*

 

Thermistors (Yellow Springs 400xx series)

YS101..07
16,17

2YS04

(1e10,I)

parallel resistance
(ohms)

0.1°C

DegC*

 

AD590 and AD592, Analog Devices

AD590

6AD590

100.0,V)

shunt resistance
(ohms)

0.1°C

DegC*

 

LM335, National Semiconductor Corp

LM335

3LM335

(2.0,V)

attenuation factor

0.1°C

DegC*

 

LM34, LM35, National Semiconductor Corp

LM34
LM35

5LM35

(1.0,V)

calibration factor

0.1°C

DegC*

State

Digital state, definable threshold

AS

7--AS

(2500,T*)

threshold
(mV)

1

State

       

*differential only

   

* also DegF, DegK, DegR

 


Reading Differential Analog Channels

The dataTaker 50 has 5 differential analog input channels, and the dataTaker 500/600 series loggers have 10 differential analog input channels. These analog input channels are used as differential channels to differentially measure analog signals.

In the differential input mode, the input signals are connected between the positive (+) terminal and the negative (ñ) terminal of each channel (See Section II ñ Differential Analog Input Mode).

Specifying Differential Channels

Differential analog input channels are specified by the general format

ntype(options)

and

n..mtype(options)

where

n                 is a single differential analog channel
n..m             is a sequence of differential analog channels
type             is the analog input signal type identifier
(options)        are channel management options

If the analog channels are located on a Channel Expansion Module, then the module number precedes the channel number(s).

Some examples of specifying differential analog input channels using DeTransfer are given below

BEGIN
 RA5M
  1V(2.5)
  2L(120)
  3..5TK
  10R(4W)
  8F
END

which returns data for the channels every 5 minutes as follows

the voltage input to channel 1, multiplied by an attenuation factor of 2.5

the 4 - 20mA current loop input to channel 2 across an external 120 Ohm shunt

the temperature from three type K thermocouples input to channels 3, 4 and 5

the resistance input to channel 10 by a 4 wire configuration

the frequency input to channel 8

In DeLogger, differential channels are specified for reading in the Program Builder by selecting the channel number and channel types descriptively from the walking menus and dialog boxes. For example

Reading Single Ended Analog Channels

The analog input channels of the dataTaker can also be used for single ended inputs, to measure analog signals that are referenced to a common point.

The dataTaker 50 supports 10 single ended analog inputs (two per physical analog channel), while the dataTaker 500/600 series loggers support 30 single ended analog inputs (three per physical analog channel).

In the single ended input mode, the input signals are applied to the analog input channels in a number of ways (See Section II - Single Ended Analog Input Mode).

The single ended measurements can be referenced to the dataTaker ground, to an external ground different to dataTaker ground, or to a 2.5 Volt reference within the dataTaker.

Single Ended Inputs Referenced to dataTaker Ground

Single ended analog inputs which are to be measured with reference to dataTaker ground are connected to analog channels as follows

between the positive terminal + and Analog Return terminal R

between the negative terminal ñ and Analog Return terminal R

between the Excite terminal T and Analog Return terminal R. This mode is not suitable for resistance or RTD inputs, and is only available in the dataTaker 500/600 series loggers

between the Analog Return terminal R and any Ground terminal G for current, current loop and AD590 temperature sensors only

Single Ended Inputs Referenced to anExternal Ground

Single ended analog inputs that are to be measured with reference to an external ground are connected to analog channels as follows

between the positive terminal + and the SE REF terminal

between the negative terminal ñ and the SE REF terminal

between the Excite terminal T and the SE REF terminal. This mode is not suitable for resistance, RTD or thermistor inputs, and is only available in the dataTaker 500/600 series loggers.

The Number of Single Ended Inputs

The single ended configurations provide for the following number of single ended channels in the dataTaker 50

15 single ended analog input channels for current, current loop and AD590 measurements

10 single ended analog input channels for all other analog signal measurements.

The single ended configurations provide for the following number of single ended channels in the dataTaker 500/600 series loggers

40 single ended analog input channels for current, current loop and AD590 temperature sensor measurements

30 single ended analog input channels for all other analog signal measurements.

Single ended input channels cannot be used for some analog input types such as 4 wire resistances, 4 wire RTDs, current excited bridges, etc. as detailed in the table of Analog Input Types above.

Specifying Single Ended Channels

When single ended inputs are measured with reference to the Analog Return terminal, the input mode is specified by suffixing the following special characters to the channel number

T   for Excite terminal single ended inputs
+   for positive terminal single ended inputs
ñ    for negative terminal single ended inputs
#   for Return terminal single ended inputs

 

The general formats of commands for specifying single ended analog inputs referenced to Analog Return follow

nTtype
n+type
nñtype
n#type

The dataTaker 50 does not support the excite terminal as an input terminal.

The positive side of the signal is connected to these terminals, and the negative side is connected to the reference (Analog Return or SE REF). The commands detailed below configure the channel inputs internally for the correct polarity.

Specifying Sequences of Single Ended Channels

The general format for specifying sequences of single ended analog inputs referenced to Analog Return follows

nT..mTtype                           nT..m+type                   nT..mñtype
n+..mT type                           n+..m+type                    n+..mñtype
nñ..mTtype                            nñ..m+type                    nñ..mñtype
                                           n#..m#type

where

n                 is a single ended analog channel
n..m             is a sequence of single ended analog channels
T                single ended input between excite T and Analog Return
+                 single ended input between positive (+) and Analog Return
–                 single ended input between negative (ñ) and Analog Return
#                 single ended input between the Analog Return (R) and Ground
type             is the input signal type identifier

If the analog channels are located on a Channel Expansion Module, then the module number precedes the channel number(s).

When sequences of single ended inputs are specified in these formats, then the actual sequence of successive single ended input channels is interpreted as follows

if the single ended channel sequence is specified in terms of the +ve and ñve terminals only, the sequence is interpreted as successive +ve and –ve terminals. For example

1+..3ñ       interprets as  1+  1ñ  2+  2ñ  3+  3ñ

if the single ended channel sequence is specified in terms of the T terminal and either the +ve or the ñve terminal, then the sequence is interpreted as successive T, +ve and ñve terminals. For example

3T..4ñ      interprets as   3T  3+  3ñ  4T  4+  4ñ

if the single ended channel sequence is specified in terms of the Analog Return # terminal, then the sequence is interpreted as successive Analog Return # terminals. For example

1#..4#       interprets as   1#  2#  3#  4#

Some examples of specifying single ended analog input channels referenced to the Analog Return (R) using DeTransfer are given below

RA1H  3+V  5-V

returns data every hour for the single ended voltage input connected between channel 3+ and R, and the single ended voltage connected between channel 5ñ and R.

R5S  1*..2ñTK

returns data every 5 seconds for the six single ended thermocouples inputs connected between channels 1T and R,  1+ and R,  1ñ and R,  2T and R,  2+ and R,  2ñ and R.

R1M  3+..4+F

returns data every minute for the three single ended frequency inputs connected between channels 3+ and R,  3ñ and R,  4+ and R.

In DeLogger, single ended channels referenced to Analog Return (R) are specified for reading in the Program Builder by selecting the channel number and channel types descriptively from the walking menus and dialog boxes.

Single Ended Inputs Referenced to an External Common

When single ended inputs have a common external ground point which is different to dataTaker ground, then these can be measured with respect to that external ground by connecting the ground to the SE REF terminal. Measurements made with respect to this external ground are actually made differentially between the input terminal and SE REF. This reference to the external common rather than to dataTaker ground is specified by the X (eXternal ground) channel option

channel(X)

The general format for specifying externally referenced single ended analog inputs is the same as that described above for single ended analog inputs referenced to Analog Return.

Some examples of specifying single ended analog input channels referenced to an external ground connected to SE REF using DeTransfer are given below

R2H  5+V(X)  6-LM35(X)

returns data every 2 hours for a single ended voltage input between channel 5+ and SE REF, and a single ended LM35 input between channel 6ñ and SE REF.

R1M  4+..5*V(X)

returns data every minute for the three single ended voltage inputs between channels 4+,  4ñ,  5T,  and SE REF

R10S  3*..4ñTK(X)

returns data every 10 seconds for the six single ended thermocouples connected between channels 3T,  3+,  3ñ,  4T,  4+,  4ñ  and SE REF.

In DeLogger, single ended channels referenced to an external grounds are specified for reading in the Program Builder by selecting the channel number and channel types descriptively from the walking menus and dialog boxes.

Combining Input Modes

Schedule lists can include a mix of differential and single ended channels, and a mix of single ended references. The list can also include a mix of single channels and channel sequences.

An example of a channel list which includes both differential and single ended analog channels is given below

R1D  1+..6-V(X)  7R  8TN  9+F  10*..10ñLM34

Reading the Same Channel for a Number of Inputs

Each analog input channel of the dataTaker data loggers can be read for any number of different analog input types if required.

For example the following readings for a type J thermocouple connected between the +ve and ñve terminals of analog input channel 3 are allowable

3V  3+V  3-V  3TJ

which will return

the differential voltage output by the thermocouple in response to temperature

the offset voltage or common mode voltage for each side of the thermocouple, with respect to dataTaker ground

the temperature sensed by the thermocouple

Page Content


Home

Title and Waranty

Go to: Section 2 | Section 3

Section 1


Construction of the dataTaker 50

Construction of the dataTaker 500 600

Construction of the CEM

Getting Started

 

Section 2


Interfacing

Powering the dataTaker

Powering Sensors from the dataTaker

The Serial Interfaces

The RS232 COMMS Serial Interface

The NETWORK Interface

Analog Process

Connect Analog

Analog Chns

Measuring Low Level Voltages

Measuring High Level Voltages

Measuring Currents

Measuring 4-20mA Current Loops

Measuring Resistance

Measuring Frequency and Period

Measuring Analog Logic State

Measuring Temperature

Measuring Temperature with Thermocouples

Measuring Temperature with RTDs

Measuring Temperature with IC Temperature Sensors

Measuring Temperature with Thermistors

Measuring Bridges and Strain Gauges

Measuring Vibrating Wire Strain Gauges

The Digital Input Channels

Monitoring Digital State

The Low Speed Counters

The Phase Encoder Counter

The High Speed Counters

The Digital Output Channels

The Channel Expansion Module

Installing The Panel Mount Display

 

Section 3


Programming the dataTaker

Communication Protocols and Commands

Entering Commands and Programs

Format of Returned Data

Specifying Channels

The Analog Input Channels

The Digital Input Channels

The Counter Channels

The Digital Output Channels

The Real Time Clock

The Internal Channels

Channel Options

Schedules

Alarms

Scaling Data - Polynomials, Spans and Functions

CVs Calcs and Histogram

Logging Data to Memory

Programming from Memory Cards

STATUS RESET TEST

Switches and Parameters

Networking

Writing Programs

Keypad and Display

Error Mess Text

Appendix A - ASCII

Appendix B - ADC Timing