Omron NT31 NT31C manual Settings at RS-232C/RS-422A Convertor Unit NT-AL001, Sysmac

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

Settings at the

RS-232C/RS-422A

Convertor Unit

(NT-AL001)

When making a connection between RS-232C and RS-422A/485 ports using an RS-232C/RS-422A convertor unit, set the DIP switches on the NT-AL001 as fol- lows.

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 NT31/NT31C and the RS-232C port of a host are connected via a convertor unit is described here.

An RS-232C/RS-422A convertor unit (NT-AL001) is used to convert between the RS-232C and RS-422A communication methods.

NT31/NT31C

Serial port B (RS-422A/485, 25-pin type)

Host link unit/CPU

SYSMAC

C-series PC,

CVM1/CV-series PC, SRM1

25-pin connector

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

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

9-pin connector or

25-pin connector

Reference: When using RS-485 as a port for the NT31/NT31C, only NT link (1:N) method (standard or high-speed) can be used.

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