Block Diagram - Omron Programmable Terminals NT31 NT31C Setup Manual

Using an RS-232C/RS-422A Convertor Unit

Block Diagram

A diagram showing the internal blocks of the convertor unit is shown below. Refer to this diagram when making
cables yourself, or when connecting devices with special interfaces.
RS-232C side
D-SUB 9P CASE
Fuse
6
+5 V
9
SG
3
RD
2
SD
4
RS
5
CS
7
DR
8
ER
264
POWER
LED
R
Photocoupler
RS-232C
Dr/Rec
R
RS-422A/485 Dr/Rec
DC-DC Convertor
IS_5 V
L L REG
IS_0 V
R R R
SW1-6
SW1-3
SW1-5
R
Terminator
RS-422A Dr
Appendix C
RS-422A/485 side
8P terminal block
1
FG
2
SG
3
SDB
4
SDA
2-wire type/
4-wire type
SW1-4
5
RDB
6
RDA
SW1-2
7
CSB
8
CSA