RS-485 communication equipment
One-pair wiring and two-pair wiring (for RS-422) are applicable for RS-485 communication. Wire according to the counterpart
equipment.
The wiring that can be used is limited by the control line setting in the communication settings (Page 136 Communication
Settings).
Control line
Bidirectional half duplex
Bidirectional full duplex
: Supported, : Not supported
■For one-pair wiring
RS-485 Communication
equipment
SDA
(TXD+)
SDB
Termination
(TXD-)
resistor
110
RDA
*2
(RXD+)
RDB
(RXD-)
LINK
SG
Class-D grounding
*1 Make sure to perform Class-D grounding on the shield of the twisted pair cable to be connected.
*2 Make sure to provide a termination resistor at both ends of the wire. The built-in RS-485 port, FX5-485-BD and FX5-485ADP have built-
in termination resistors. Set the termination resistor selector switch to 110 .
Precautions
When the control line is set to [Bidirectional Full Duplex], the built-in RS-485 port, FX-485-BD and FX5-485ADP become a
full-duplex interface, and echo will occur.
■For two-pair wiring
RS-485/RS-422 Communication
equipment
SDA
(TXD+)
SDB
*2
(TXD-)
RDA
(RXD+)
RDB
*2
(RXD-)
Termination
LINK
resistor
SG
330 × 2
Class-D grounding
*1 Make sure to perform Class-D grounding on the shield of the twisted pair cable to be connected.
*2 Make sure to provide a termination resistor at both ends of the wire. The built-in RS-485 port, FX5-485-BD and FX5-485ADP have built-
in termination resistors. Set the termination resistor selector switch to 330 .
One-pair wiring
Built-in RS-485 port
FX5-485-BD
FX5-485ADP
SDA
(TXD+)
SDB
(TXD-)
RDA
(RXD+)
RDB
(RXD-)
SG
*1
Class-D grounding
Built-in RS-485 port
FX5-485-BD
FX5-485ADP
SDA
(TXD+)
SDB
(TXD-)
RDA
(RXD+)
RDB
(RXD-)
SG
*1
Class-D grounding
Two-pair wiring
Built-in RS-485 port
FX5-485-BD
FX5-485ADP
SDA
(TXD+)
SDB
Termination
(TXD-)
resistor
110
RDA
*2
(RXD+)
RDB
(RXD-)
SG
*1
Built-in RS-485 port
FX5-485-BD
FX5-485ADP
SDA
(TXD+)
SDB
*2
(TXD-)
RDA
(RXD+)
RDB
*2
(RXD-)
Termination
resistor
SG
330 × 2
*1
5 NON-PROTOCOL COMMUNICATION
5
135
5.5 Wiring