Mitsubishi Electric FR-F820-00046 Instruction Manual page 478

 RS-485 terminal wiring method
• Wiring between a computer and an inverter for RS-485 communications
• Wiring between a computer and multiple inverters for RS-485 communication
Computer
RDA
RDB
SDA
SDB
RSA
RSB
CSA
CSB
SG
FG
*1 Make connection in accordance with the Instruction Manual of the computer to be used with.
Fully check the terminal numbers of the computer since they vary with the model.
*2 On the inverter most remotely connected with the computer, set the terminating resistor switch in the ON (100 Ω) position.
NOTE
• For branching, connect the wires as shown in the following table.
To computer ground
To computer receive
To computer send
 Two-wire type connection
• If the computer is 2-wire type, a connection from the inverter can be changed to 2-wire type by passing wires across
reception terminals and transmission terminals of the RS-485 terminals.
Transmission
enable
Reception
enable
Computer
RDA
RDB
SDA
SDB
RSA
RSB
∗1
CSA
CSB
SG
FG
∗1
SG SG
Station 0
VCC TXD RXD
Computer
Pass a wire
SG
∗2
SG
SG SG SG
Station 1
VCC TXD RXD
To receiving terminal
of the next inverter
To sending terminal
of the next inverter
To next inverter
To earth (ground)
terminal
Inverter
TXD+
TXD-
RXD+
RXD-
SG
5.12 (N) Communication operation parameters
∗2
Station n
10
477
5. PARAMETERS
1
2
3
4
5
6
7
8
9