Omron NT31 NT31C manual 103

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

Settings at the Host

When using the RS-422A type host link method, the settings shown below must be made at the host (depending on the unit, some of these settings may not be necessary, or settings not shown here may be necessary).

Item	Setting at Host
I/O port	RS-422A
Communications speed	Set the same speed as for the NT31/NT31C. (*1)
Transfer code	ASCII, 7 data bits, 2 stop bits
Parity	Even
1-to-1/1-to-N	1-to-N(*2)
Instruction level	Level 1, 2, 3
Unit #	00

*1 Set the host link communications speed at 9600 bps or 19200 bps with the Comm. Speed memory switch at the NT31/NT31C. For details, refer to Setting the Host Link Method (page 158).

*2 The 1-to-N setting enables BCC (Block Check Character). It is not actually possible to connect more than one NT31/NT31C in a single host link.

The setting methods for each type of unit are described in the following.

Connecting to a C Series Host Link Unit C200H/C200HS/C200HE(-Z)E/C200HG(-Z)E/C200HX(-Z)E Backplane mounting type: C200H-LK201-V1

Setting the Front Switches

Set each switch with a flat blade screwdriver so that the values or symbols in the setting value window agree with the following:

LK201
RUN	XMT
RCV	ERROR

SW1SW2

0 0

SW3SW4

5 2

@Unit # (SW1, SW2)

Set these switches to 0.

@Instruction level, parity, and transfer code (SW4) Set this switch to 2.

@Communications speed (SW3)

Set this switch to 5 to select 9600 bps. Set this switch to 6 to select 19200 bps.

Setting the Rear Switches

Terminator

ON

OFF

@Terminator setting (selector switch) Set this switch to ON.

1-to-1 (ON)

1-to-N (OFF)

@1-to-1/1-to-N protocol selection (selector switch) Set this switch to 1-to-N (OFF).

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