470
Temperature Sensor Units Section 7-5
Connecting Temperature
Sensors
Thermocouples
Either K or J thermocouples can be connected, but all twelve of the thermo-
couples must be of the same type and the same input range must be used for
each.
Note When connecting a thermocouple input, observe the following precautions:
• Do not remove the cold junction compensator attached at the time of
delivery. If the cold junction compensator is removed, the Unit will not be
able to measure temperatures correctly.
• Each of the input circuits is calibrated with the cold junction compensator
attached to the Unit. If the Unit is used with the cold junction compensator
from other Units, the Unit will not be able to measure temperatures cor-
rectly.
• Do not touch the cold junction compensator. Doing so may result in incor-
rect temperature measurement.
• Use the thermocouple with metallic shield and connect the shield to
ground.
Open-circuit Detection
Function for Temperature
If the circuit is disconnected, the open-circuit detection function will operate
and the converted temperature data will be set to 7FFF.
Creating a Ladder
Program
Word Allocations
Temperature Sensor Units are allocated words in the same way as other CP-
series Expansion Units or Expansion I/O Units, in order of connection. A Tem-
perature Sensor Unit is allocated the next input words following the input
words of the CPU Unit or previous Expansion Unit or Expansion I/O Unit. Two
input words and one output word are allocated to CP1W-TS004.
Example
Temperature Data Read Operation
There are 12 temperature input data to be read, but only two input words are
allocated to CP1W-TS004. The operation is shown as the following.
Temperature input 0
Temperature input 1
Temperature input 11
Cold junction
compensator
CIO 102
CP1H
Input word
addresses
Output word
addresses
CIO 0
CIO 1
CIO 100
CIO 101
CIO 2
CIO 3
CP1W-TS004
Temperature Sensor Uni
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