Omron NT631C manual 5 1N Connection among RS-485 Ports, C200HX-CPU65-ZE/85-ZE CQM1H-CPU51/61

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

C200HX-CPU65-ZE/85-ZE

CQM1H-CPU51/61

Note A Serial Communications Board cannot be installed.

RDA NT631/NT631C side

PLC side 1 6

TRM

RDB

SDA

SDB

RSA

RSB

24V

+DC

RS-422A/ 485 interface

Abbreviation

Shielding wire

RDA (-)

TRM

RDB (+)

SDA (-)

SDB (+)

RSA (-)

RSB (+)

Functional ground

Next PT

Pin number Abbreviation

Connector	FG
hood

1SDA (-)

2SDB (+)

3	−	RS-422A
4	−	interface

5−

6RDA (-)

7−

8RDB (+)

9−

(9-pin type) 5 9

For details on handling shield wires, refer to 5-2-8 Handling the Shield on RS- 422A/485 Cables on page 125.

5-2-5 1:N Connection among RS-485 Ports

The connection method in which the RS-485 ports of multiple NT631/

NT631Cs and one host are connected in a 1:N connection is described here.

CPU Unit

CS/CJ-series or

C200HX/HG/HE(-Z)E

PLC

RS-485 cables	9-pin connector
(max. total length 500 m)

NT631/NT631C

Serial port B (RS-422A/485, terminal block)

NT631/NT631C

NT631/NT631C

Reference: • Communications using the RS-485A standard NT link (1:N) method is possible only when a Serial Communications Board is installed in a CS- series PLC, a Serial Communications Unit is installed in a CS/CJ-series PLC, a Communications Board is installed in a C200HX/HG/HE(-Z)E, or a CQM1H-SCB41 Serial Communications Board is installed in a CQM1H.

•Communications using the RS-485A high-speed NT link (1:N) method is possible only when a Serial Communications Board is installed in a CS- series PLC or a Serial Communications Unit is installed in a CS/CJ-series PLC.

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