Omron NT31 NT31C manual 106

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

Connecting to a CVM1/CV Series Host Link Unit

CVM1/CV series rack-mounting type: CV500-LK201

A CVM1/CV series host link unit (CV500-LK201) has two connectors (commu- nication ports 1 and 2). To use the RS-422A type host link method, set commu- nication port 2 to RS-422A.

Communication port 2 is a 9-pin connector which allows selection of the RS-232C or RS-422A method. When this port is used with the RS-422A method, the I/O port selector switch on the front of the unit must be set to RS-422A (the lower position).

CPU Bus Unit Settings

When connecting to a CVM1/CV series host link unit, set the following commu- nication conditions for the CPU bus unit settings.

Item	Setting at Host
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

*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).

*1 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.

Set the CPU bus unit settings directly from a Programming Device (e.g. SYS-

MAC support software).

For details on the CPU bus unit settings, refer to the SYSMAC CVM1/CV-series

Host Link Unit Operation Manual (W205-E1-j).

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