Omron CQM1H-SCB41 operation manual WiringSection

WiringSection 2-3

2-3-4 Port Applicability and Restrictions for 2-Wire/4-Wire Connections

The following table shows the port connections that can be used for each serial communications mode.

Serial communications	RS-232C port					RS-422A/485 port
mode
	1:1	1:N		4-wire				2-wire
				1:1		1:N	1:1		1:N
Host Link	OK	OK (See	OK		OK		No		No
		note 2)
Protocol macros	OK		OK		OK		OK		OK
No-protocol	OK		OK		OK		No		No
1:1 Data Links	OK	No	OK		No		No		No
1:N-mode NT Links	OK		OK		OK		OK		OK
1:1-mode NT Links	OK	No	OK		No		No		No

Note 1. The 1:N connection method can be used by converting between RS-232C and RS-422A/485 through NT-AL001-E Converting Link Adapters.

2.Use 4-wire connections between the Converting Link Adapters.

3.The 2-wire RS-422A/485 connections cannot be used for Host Link commu- nications. Use 4-wire connections.

The transmission circuits for 2-wire and 4-wire connections are different, as shown in the following diagram.

Example of 4-Wire Connections Example of 2-Wire Connections

2/4-wire switch		2/4-wire switch
(DPDT)	Other Unit	(DPDT)	Other Unit	Other Unit
Other Unit
			Not connected
		Board
Board

Note 1. Use the same transmission circuit (2-wire or 4-wire) for all nodes.

2.Do not use 4-wire connections when the 2/4-wire switch on the Board is set to 2-wire.

NT-AL001-E Link Adapter The NT-AL001-E Link Adapter has a DIP switch for setting RS-422A/485 com-

Settingsmunications conditions. When connecting the Board, refer to the DIP switch set- tings shown in the following table.

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