Omron NT31 Operation Manuals page 668

Using an RS-232C/RS-422A Convertor Unit
DIP Switch Settings
The convertor unit has 6 digits DIP switch for setting the RS-422A/485 communication conditions.
Before connecting the cable to the convertor unit, make the DIP switch settings.
ON
1 2 3 4 5 6
When using the host link or NT link (1:1), set the RS-422A send mode to "continual sending" (set both SW1-5 and 6
"OFF").
When using the NT link (1:N), set the RS-422A send mode to "complies with CS control of RS-232C" (i.e., one of
SW1-5 and SW1-6 must be ON).
(Factory settings)
om on
[SW1-1] Not used (always ON)
[SW1-2] Setting for built-in terminal resistance
- OFF Terminator not set
- ON Terminator set
[SW1-3, 4] Selection of 2-wire type/4-wire type
SW1-3
OFF
ON
SW1-3
OFF
ON
[SW1-5, 6] Selection of the RS-422A send mode
SW1-5
OFF
ON
SW1-5
OFF
ON
SW1-5
OFF
ON
R NT–AL001
SW1-4
2-wire type (RS-485)
SW1-4
4-wire type (RS-422A)
SW1-6
Continual sending
SW1-6
Complies with CS control of RS-232C
(Data sent at CS "H")
SW1-6
Complies with CS control of RS-232C
(Data sent at CS "L")
APPENDIX C
657