Omron NT31 NT31C Network Card User Manual


 
Appendix CUsing an RS-232C/RS-422A Convertor Unit
262
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.
123456
OFF
ON
SW1-3 SW1-4
ON
om on
R
NT–AL001-E
(Factory settings)
[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
2-wire type (RS-485)
SW1-3 SW1-4
OFF
ON
4-wire type (RS-422A)
SW1-5 SW1-6
SW1-5 SW1-6
SW1-5 SW1-6
[SW1-5, 6] Selection of the RS-422A send mode
Continual sending
Complies with CS control of RS-232C
(Data sent at CS high)
Complies with CS control of RS-232C
(Data sent at CS low)
OFF
ON
OFF
ON
OFF
ON
When using the host link or 1:1 NT Link, set the RS-422A send mode to continual sending (set both SW1-5 and 6
OFF).
When using the 1:N NT Link (standard or high-speed), 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).
Note 1. Do not set both SW1-5 and SW1-6 ON at the same time. This may damage internal circuits.
2. The power supply to the device supplying +5 V must be turned OFF before starting wiring work.
3. Before connecting the RS-232C cable and turning on the power to an RS-232C device such as a PT
(i.e., turning on the power to the convertor unit), check that the cable is wired correctly and that the DIP
switch settings are correct. If the power is turned on while there is a wiring fault, the internal circuits of the
convertor unit or the RS-232C device may be damaged.
4. When the convertor unit is connected to a C200HX/HG/HE (-ZE), CQM1H, CS1G/H model of OMRON
PC as an RS-422A device, set DIP switches SW1-5 and SW1-6 as indicated below.
56
SW1-5
OFF
SW1-6
ON