Mitsubishi Electric FR-A500 Instruction Manual page 36

<Wiring method>
1) Wiring of one RS-485 computer and one inverter
Computer Side Terminals
Signal name Description
RDA Receive data
RDB Receive data
SDA Send data
SDB Send data
RSA Request to send
RSB Request to send
CSA Clear to send
CSB Clear to send
SG Signal ground
FG Frame ground
2) Wiring of one RS-485 computer and "n" inverters (several inverters)
Computer
RDA
RDB
SDA
SDB
RSA
RSB
CSA
CSB
SG
FG
Note: 1. Make connections in accordance with the instruction manual of the computer used.
Fully check the terminal numbers of the computer as they differ between models.
2. There may be the influence of reflection depending on the transmission speed and/or
transmission distance. If this reflection hinders communication, provide a terminal resistor. If the
PU connector is used to make a connection, use a distributor as a terminal resistor cannot be
fitted. Connect the terminal resistor only to the inverter remotest from the computer. (Terminal
resistor: 100Ω)
Cable connection and signal direction
10BASE-T Cable
(Note 1)
Cable connection and signal direction
10BASE-T Cable
(Note 1)
SG
Station 1
Inverter
27
INSTALLATION AND WIRING
2
0.2mm or more
SG SG
Station 2 Station n
Inverter Inverter
Inverter
PU connector
SDA
SDB
RDA
RDB
SG
2
Termination
resistor
(Note 2)