Omron CJ Series Operation Manual page 138

3 Isolated-type Universal Input Units
Precautions for Safe Use
• Do not remove the cold junction sensors that are connected to the CJ+ and CJ− terminals. If
they are removed, compensation will not be executed and temperatures will not be correctly
measured.
• Use the cold junction sensors that are included with the product. Cold junction sensors are cal-
ibrated for particular Units. If a sensor from another Unit is used, temperatures cannot be cor-
rectly measured.
Precautions for Correct Use Precautions for Correct Use
• When wiring voltage inputs, be careful not to connect the wrong terminals. Incorrect wiring
may damage the Unit.
• Use the same wiring length for connecting to A, B, a, and b, so that the impedance will be the
same. In particular (for resistance thermometers), do not connect the A-a and B-b terminals.
• Do not connect anything to unused terminals.
• Always ground the GR terminal on the Power Supply Unit.
• Be sure to ground all input devices (such as voltage generators, temperature calibrators, and
resistors) that have ground terminals.
Shielded Cable
When the Resolution and Process Data Length Setting is set to 1/16,000
cable as shown in the following figure.
Thermocouple Input
3-34
Input 1
1 to 4-A B1(10)
A1(1)
+
A2(2) B2(11)
1 to 4-B
−
B3(12)
1 to 4-C A3(3)
1 to 4-D A4(4) B4(13)
CJ-series Analog I/O Units Operation Manual for NJ-series CPU Unit(W498)
Input 2 Input 3 Input 4
A6(6) B6(15)
A7(7) B7(16)
A8(8) B8(17)
A9(9) B9(18)
5ms, connect shielded
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