Omron CJ1W-SCU32 Operation Manual page 131

Connection examples are shown with the following diagrams.
2-wire Connections
Serial Communications Unit
Pin
Signal
1 RDA
2 RDB
3 SDA
4 SDB
5 FG
4-wire Connections
Serial Communications Unit
Pin
Signal
1 RDA
2 RDB
3 SDA
4 SDB
5 FG
Serial Communications Unit
Pin
Signal
1 RDA
2 RDB
3 SDA
4 SDB
5 FG
Note The FG terminal on the Serial Communications Unit is internally connected to the ground ter-
minal (GR) on the Power Supply Unit via the CPU Rack or Expansion Rack. Therefore,
ground the ground terminal (GR) on the Power Supply Unit to ground the FG.
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
Remote device
Shield
Shield
Remote device
RS-422
Signal
SDA
SDB
RDA
RDB
FG
Remote device
RS-422
Signal
SDA
SDB
RDA
RDB
FG
Power Supply Unit
GR
Ground to 100 Ω or less.
If you ground the GR
terminal, the shell or FG
terminal is also grounded.
Signal
A(−)
B(+)
FG
Remote device
Signal
RDA
RDB
SDA
SDB
FG
Serial Communications Unit
SCU32
RUN ERC
RDY ERH
TERM
OFF ON
WIRE
2 4
The shell or FG terminal
and GR terminal are
internally connected.
3 Installation and Wiring
SD1 RD1 TER1
SD2 RD2 TER2
UNIT
NO.
PORT1
(RS422
/485)
RDA-
RDA+
SDA-
SDA+
FG
PORT2
(RS422
/485)
RDA-
RDA+
SDA-
SDA+
TERM
FG OFF ON
WIRE
2 4
3
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