Omron Programmable Terminals NT31 NT31C Setup Manual page 131

Connecting to the Host's RS-422A/485 Port
1
13
120
CVM1/CV-series CPUs whose model names do not have the suffix -EVj can-
not be connected by any connection method.
14 NT31/NT31C side
Abbreviation Pin number
Connector
FG
hood
−
1
SD 2
RS-232C/
422A/485
RD 3
connector
RS
4
CS 5
−
6
SG
7
−
8
TRM
9
RDB (+) 10
SDB (+) 11
−
12
−
13
−
14
SDA (−)
25 15
RDA (−) 16
−
− −
RSB (+) 23
RSA (−)
24
−
25
(25-pin type)
In order to avoid an FG ground loop, do not connect the functional ground of the
NT31/NT31C to the shielding of the RS-422A cable.
Wiring for a Memory Link Connection
Prepare the adapter cable while referring to the following diagram.
1
13
In order to avoid an FG ground loop, do not connect the functional ground of the
NT31/NT31C to the shielding of the RS-422A cable.
PC (CPU) side
Pin number Abbreviation
Connector
FG
hood
1 SDA
RS-422A
2 SDB connector
−
3
4 RS
5 CS
6 RDA
−
7
8
RDB
−
9
(9-pin type)
Shielding wire
14
NT31/NT31C side
Abbreviation Pin number
Connector
FG
hood
−
1
SD
RS-232C/ 2
422A/485
RD 3
connector
RS
4
CS 5
−
6
SG
7
−
8
TRM 9
RDB (+)
10
SDB (+) 11
−
12
−
13
−
14
SDA (−)
25 15
RDA (−) 16
−
− −
RSB (+) 23
RSA (−) 24
−
25
(25-pin type)
Section
6
1
9
5
Host side
Abbreviation
Connector
hood
SDA
RS-422A
SDB connector
RS
CS
ROA
ROB
Shielding wire
5-2