Two-Pair Wiring - Mitsubishi Electric FX3U-232-BD User Manual

FX Series PLC User's Manual - Data Communication Edition
Computer Link
4.5.2

Two-pair wiring

Communication
equipment operating
in accordance with
RS-485/RS-422
SDA
(TXD+)
SDB
*3
(TXD-)
RDA
(RXD+)
RDB
*3
(RXD-)
Terminal
resistor:
LINK
330 
× 2
SG
*1. Make sure to perform Class-D grounding on the shield of a twisted pair cable connected to
the FX -485-BD, FX
2N
FX -485ADP(-MB).
3U
*2. Make sure to connect the
Class-D grounding.
If the grounding terminal is not provided in the PLC, perform Class-D grounding directly.
*3. Make sure to provide a terminal resistor at the end of each line.
• The FX
3U
Set the terminal resistor selector switch accordingly.
• The FX
terminal resistors.
FX -485ADP
0N
SDA
(TXD+)
SDB
(TXD-)
RDA
(RXD+)
RDB
(RXD-)
LINK
SG
FG *2
(resistance: 100  or less)
-485-BD, FX
1N 3G
terminal to the
FG
-485-BD, FX -485-BD and FX
3G
-485ADP, FX -485ADP, FX
0N 2NC
FX -485-BD
3U
FX -485-BD
3G
FX -485-BD
2N
FX -485-BD
1N
FX -485ADP(-MB)
3U
SDA
(TXD+)
SDB
(TXD-)
RDA
(RXD+)
RDB
(RXD-)
SG
Class-D grounding
(resistance: 100  or less)
*1
-485-BD, FX -485-BD, FX
3U
(grounding) terminal in the PLC requiring
-485ADP(-MB) have a built-in terminal resistor.
3U
-485-BD and FX -485-BD are supplied together with
2N 1N
4.5 Connection Diagram for RS-485 and RS-422
FX -485ADP
2NC
SDA
(TXD+)
SDB
(TXD-)
RDA
(RXD+)
RDB
(RXD-)

SG
Class-D grounding
*1
-485ADP or
2NC
4 Wiring
A
B
*3
C
*3
Terminal
resistor:
330 
× 2
D
E
F
G
H
I
Apx.A
D-37