Omron NT631C manual Example the terminal resistor is active RS-422A, NT Link 1N

Connecting to the Host’s RS-232C Port Section 5-1

Example: the terminal resistor is active,

RS-422A, NT Link (1:N).

ON

1 2 3 4 5 6

omRon NT-AL001

Built-in terminal resistor setting (DIP SW1-2)

If at the end of the RS-422A/485 cable, set this switch to ON (to activate the built-in terminal resistor).

If not at the end of the RS-422A/485 cable, set this switch to OFF (to inactivate the built-in terminal resistor).

2-wire type/4-wire type selection (DIP SW1-3, SW1-4)

For RS-422A, set both of these switches to OFF (4-wire type). For RS-485, set both of these switches to ON (2-wire type).

Selection of RS-422A/485 send mode (DIP SW1-5, SW1-6) For host link or NT Link (1:1), set both of these switches to OFF. (Always send)

For NT Link (1:N), set SW1-5 to OFF and SW1-6 to ON. (Sends when CS is H)

Note Read the manual supplied with the NT-AL001 carefully before using the Unit.

5-1-2 1:1 Connection between RS-422A/485 at the PT and RS-232C at the Host

The connection method in which the RS-422A/485 port of an NT631/NT631C and the RS-232C port of a host are connected via a Adapter is described here.

An RS-232C/RS-422A Adapter (NT-AL001) is used to convert between the

RS-232C and RS-422A communications methods.

NT631/NT631C

RESET
RDA
TRM
RDB
SDA
SDB
CSA
CSB
24V	PR I NTER PORT B PORT A
+DC

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

RS-232C/RS-422A convertor unit (NT-AL001)

Host Link Unit or CPU Unit

SYSMAC

CS/CJ-series PLC

C-series PLC,

CVM1/CV-series PLC,

SRM1

9-pin connector or

25-pin connector

RS-422A/485 cable	RS-232C cable
(max. length: 500 m)
	with connectors
RS-422A terminal block	9-pin connector

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