IT-1602 module for the measurement of thermocouples and mV signals

TCL2 modules 18.03.2020 16:25 18.03.2020 16:25

The module is not recommended for new installations, its successor is IT-1605

The IT-1602 expansion module contains 8 analogue inputs with a common terminal and 2 analogue outputs with a common terminal. The inputs are universal, independently configurable as voltage inputs or for direct connection of thermocouples. A compensation of the cold end is implemented by an external sensor Ni1000 connected to the CJC input (the cold junction compensation). The sensor needs to be placed on the terminal block, where the compensating cables are terminated (the equipotential terminal block). With 16-bit resolution, the module provides the processing of the values measured, convertion to engineering units, etc. The analogue outputs have a 10-bit resolution, bipolar -10 to + 10 V voltage. The analogue inputs and outputs are galvanically isolated from the internal circuits and the status of each input is indicated on the module panel.

 

 

 

The analogue inputs AI0 ÷ AI7

Voltage ranges

-0.1 ÷ +0.1 V

-1 ÷ +1 V

Thermocouples

J

K

R

S

B

T

N

–210 ÷ +1200 °C

–200 ÷ +1372 °C

–50 ÷ +1768 °C

–50 ÷ +1768 °C

+250 ÷ +1820 °C

–200 ÷ +400 °C

–200 ÷ +1300 °C

Input impedance in signal range:

> 1 MΩ

Measurement time of one channel

typically 65 ms (100 ms for thermocouples)

Recovery time value of each channel

typically 500 ms (800 ms for thermocouples)

Cold junction compensation sensor (CJC)

Ni1000, W100 = 1.617

 

 

The analogue outputs AO0, AO1

Output range

-10 V ÷ 10 V

Maximum output value

105 % of the output range upper limit

A minimum output value

-105 % low limits of the output range

Maximum output current

10 mA

Maximum load capacity

50 nF

 

 

Basic parameters

Supply voltage

24 VDC, +25 %, –15 %

Typical power consumption

1.7 W

Maximum power consumption

2.5 W

 

 

 

The connectors of the module are standard removable ones with a cage terminal in the removable part with 5.08 mm spacing. A flat-head screwdriver with the tip width of 3.5 mm is recommended for manipulation with the terminal. Detailed parameters of the connectors are specified in Chapter 13.3.1 Connectors with screw terminals, spacing 5.08 mm, modules on a DIN rail.

 


Fig. 1 The basic wiring diagram of the IT-1602 module

Wiring notes:

  1. The analogue inputs and outputs have a common AGND terminal.

  2. To improve the accuracy of measurement, it is recommended to connect the input signals (sensors) in accordance with the example, i.e. to use the B1 terminal as a common AGND terminal for the analogue inputs (the A5 for the analogue outputs and the A8 for the cold junction compensation).

  3. The CJC input is designed only to measure the cold junction during direct measurement of thermocouples. The connected sensor must be the Ni1000 type.