Omron NT631C manual Examples of Applicable Terminals, For M3.5

Connecting to the Host’s RS-422A/485 Port				Section 5-2
	Name	Model	Maker	Remarks
	Crimp ter-	1.25-N3A	Japan Solderless	Recommended cable size:
	minals	(fork type) *1	Terminal MFG	AWG22 to 18
		Y1.25-3.5L (fork	Molex Inc.	(0.3 to 0.75 mm2)
		type) *1

*1 Crimp terminals of common use for M3 and M3.5

The terminal screws of the NT631/NT631C are M3.5 specification. When wir- ing, use crimp terminals for M3.5 use. Tighten terminal screws with a tighten- ing torque of 0.8 N⋅m.

The terminal screws of the RS-422A adaptor (CPM1-CIF11) are M3 specifica- tion. When wiring, use crimp terminals for M3 use. Tighten terminal screws with a tightening torque of 0.5 N⋅m.

Note 1. Make sure to tighten screws at the connectors after cable connection.

2. Always use crimp terminals for wiring at terminal blocks.

Examples of Applicable Terminals

• For M3.5

Fork type

7 mm max.

Round type

7 mm max.

• For M3

Fork type

6.2 mm max.

Round type

6.2 mm max.

5-2-7 Setting the Terminal Resistance for RS-422A/485 Communications

The serial port B connector of the NT631/NT631C has a terminal resistance setting terminal (TRM).

In RS-422A/485 communications, a terminal resistor must be set at the device at the end of the communications cable, but not at any other device.

The NT631/NT631C has a built-in terminal resistor, and whether or not the terminal resistance is applied is set by shorting or opening the terminal resis- tance setting terminals (TRM). The terminal resistance is 120 Ω.

When carrying out RS-422A/485 communications using serial port B, short between terminals at the NT631/NT631C at the end of the RS-422A/485 cable. Leave these terminals open at NT631/NT631C PTs other than the one at the end of the cable.

When not using RS-422A/485 communications, the terminal resistance set- ting is ineffective.

Short-circuit tool

RDA

TRM

RDB

SDA

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