Omron NT31 NT31C manual 4 1N Connection among RS-422A Ports

Connecting to the Host’s RS-422A/485 Port Section 5-2

C200HX-CPU65-ZE C200HX-CPU85-ZE

CQM1H-CPU51CQM1H-CPU61

114

1325

NT31/NT31C side

Abbreviation Pin number

Connector

FG hood

−1

RS-232C/	SD	2
422A/485	RD	3
connector
	RS	4
	CS	5
	−	6
	SG	7
	−	8
	TRM	9
	RDB (+)	10
	SDB (+)	11
	−	12
	−	13
	−	14
	SDA (−)	15
	RDA (−)	16
	−
	−	−
	RSB (+)	23
	RSA (−)	24
	−	25

(25-pin type)

Shielding wire

PC (CPU) side

Pin number	Abbreviation
Connector	FG
hood
1	SDA (−)	RS-422A
2	SDB (+)	connector
3	−
4	−
5	−
6	RDA (−)
7	−
8	RDB (+)
9	−

(9-pin type)

16

59

In order to avoid an FG ground loop, do not connect the functional ground of the

NT31/NT31C to the shielding of the RS-422A cable.

5-2-4 1:N Connection among RS-422A Ports

The connection method in which the RS-422A ports of multiple NT31/NT31Cs and one host are connected in a 1:N connection is described here.

CPU

NT31/NT31C

Serial port B (RS-422A, 25-pin type)

25-pin connector

Relay terminal block

Max. 2 m

CS1G/H C200HX/HG/HE(-Z)E CQM1H

9-pin connector

RS-422A cables

(max. total length 500 m)

24V

DCPRINTER PORT B

122