Omron NT631 Operation Manuals page 143

Connecting to the Host's RS-422A/485 Port
S Wiring when connecting a CVM1/CV-series CPU
Applicable units:
CV500-CPU01-EV1
CV2000-CPU01-EV1
CVM1-CPU01-EVj
CVM1-CPU21-EVj
CVM1/CV-series CPUs whose model names do not have the suffix "-EVj" can-
not be connected by any connection method.
NT631/NT631C side
RDA
TRM
RDB
RS-422A/
SDA
485
interface
SDB
RSA
RSB
24V
+DC
In order to avoid an FG ground loop, do not connect the functional ground of the
NT631/NT631C to the shielding of the RS-422A cable.
Short-circuit tool
Abbreviation
Pin number
Shielding wire
Connector
RDA (−)
hood
TRM
RDB (+)
SDA (−)
SDB (+)
RSA (−)
RSB (+)
Functional
ground
Section 5-2
CV1000-CPU01-EV1
CVM1-CPU11-EVj
1
PLC side
Abbreviation
FG
1 SDA (−)
2 SDB (+)
−
3
RS-422A
4 PS
interface
CS
5
RDA (−)
6
−
7
RDB (+)
8
−
9
5
(9-pin type)
6
9
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