Omron CS1W-SCU21 Operation Manual page 239

CompoWay/F Master Protocol
RS-422 4-wire Connections
• RS-422 connections can be one-to-one, or one-to-N when a 3G2A9-AL001 Link Adapter is used. A maxi-
mum of 32 Serial Communications Boards and Unit can be connected in one-to-N systems.
• The total cable length can be 500 m max.
• Use shielded, twisted-pair cable.
• Be sure to turn ON the terminating resistance switches at the device at each end of the transmission line.
*1: Set the 2-/4-wire switch
to the 4-wire setting.
*2: Turn ON the terminat-
ing resistance switch.
RS-485 2-wire Connections
• RS-485 connections can be one-to-one or one-to-N. A maximum of 32 Serial Communications Units/
Boards can be connected in one-to-N systems.
• The total cable length can be 500 m max.
• Use shielded, twisted-pair cable.
• Be sure to turn ON the terminator switches only in the devices at each end of the transmission line.
Serial Communications Board/Unit
Abbreviation
*1: Set the 2-/4-wire switch
to the 2-wire setting.
*2: Turn ON the terminat-
ing resistance switch.
Note SYSMAC BUS Wired Remote I/O devices cannot be connected.
220
Serial Commu-
nications Board/Unit
RS-422
Abbreviation
Shell
6
8
1
2
Shield
Intelligent Signal Processor
Turn OFF all terminal block
switches except at the end-station.
RS-485
Termi
nal
Shell
1
2
Shield
Intelligent Signal
Processor
Terminal
220 Ω
block switch
Ab-
Pin
brevi-
No.
ation
220 Ω
The terminator (220 Ω) is set with the terminal block switch.
Terminal
block
Ab-
220 Ω
switch
brevi
ation
+
Intelligent Signal
Processor end-station
Ab-
Termi
brevi 220 Ω
nal
ation
+
Terminal block switch ON at the end station.
Shield
Appendix B
SN751177N or equivalent
SN751177N or equivalent
Terminal
block switch ON