Omron NT31 Operation Manuals page 94

Connecting to the RS-232C Port at the Host
S Connecting to CVM1/CV series (-EVj)
Set the DIP switches on the front panel as follows.
When using the CVM1/CV series, "CPU execution processing (execution con-
trol 2)" in the PC system settings must be set to "Simultaneous processing".
I/O port selection (selector switch)
Set this to "RS-232C".
DIP switch setting (SW3)
6
5
Set SW3 to "use NT link"
4
3
("ON", right side).
2
1
ON
OFF
ON
Section 4-1
83