Omron NT31 Operation Manuals page 669

Using an RS-232C/RS-422A Convertor Unit
Pin Arrangement
The convertor unit has a terminal block for an RS-422A/485 interface connection and a connector for an RS-232C
interface connection.
The pin arrangements for the RS-422A/485 terminal block and the RS-232C connector are as follows.
RS-422A/485 Terminal Block
Terminal
block pin No.
8
8
7
7
6
5
4 6
3
2 5
1
4
3
2
1
* The CSB and CSA signals are for specialized applications.
658
Note S Do not set both SW1-5 and SW1-6 ON at the same time. This may damage inter-
nal circuits.
S The power supply to the device supplying +5 V must be turned OFF before start-
ing wiring work.
S 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 conver-
tor unit or the RS-232C device may be damaged.
S When the convertor unit is connected to a C200HX/HG/HE (-ZE) model of OM-
RON PC as an RS-422A device, set DIP switches SW1-5 and SW1-6 as indi-
cated below.
Signal name
Request to send (−)
Request to send (+)
Receive data (−)
Receive data (+)
Send data (−)
Send data (+)
Signal ground
Functional ground
SW1-5 SW1-6
OFF ON
5 6
Abbreviation
CSA
CSB
RDA
RDB
SDA
SDB
SG (GND)
APPENDIX C
Signal direction
(convertor unit ⇔ RS-422 device)
→
→
←
←
→
→
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