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3 Installation and Wiring
3-16
CJ-series Serial Communications Units Operation Manual for NJ-series CPU Unit(W494)
1:N Connections Using RS-422A/485 Ports
1
2
3
4
5
RDA
RDB
SDA
SDB
FG
A(
−
)
B(+)
A(
−
)
B(+)
Terminal block connector
RS-422A/
485 Inter-
face
Serial Communications Unit
Pin
Signal
RS-422A/
485 Inter-
face
RS-422A/
485 Inter-
face
Signal
Signal
Device that supports
RS-422A/485
communications
(2-wire)
Device that supports
RS-422A/485
communications
(2-wire)
Terminal block connector
RS-422A/
485 Inter-
face
Serial Communications Unit
Shield
Device that supports
RS-422A/485
communications
(4-wire)
Device that supports
RS-422A/485
communications
(4-wire)
RS-422A/
485 Inter-
face
RS-422A/
485 Inter-
face
Pin
Signal
Signal
Signal
1
2
3
4
5
RDA
RDB
SDA
SDB
FG
RS-422A
RS-422A
SDA
SDB
RDA
RDB
SDA
SDB
RDA
RDB