Mitsubishi Electric FR-S520E Series Instruction Manual page 60

Handling of the RS-485 connector
<Wiring methods>
1) Wiring of one RS-485 computer and one inverter
Computer Side Terminals
Signal
Description
name
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
REMARKS
*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 change with the model.
*2. The inverters may be affected by reflection depending on the transmission speed or
transmission distance. If this reflection hinders communication, provide a terminating
resistor. When the RS-485 connector is used for connection, a terminating resistor cannot
be fitted, so use a distributor. Connect the terminating resistor to only the inverter remotest
from the computer. (Terminating resistor: 100Ω)
Cable connection and signal direction
10 BASE-T Cable
Cable connection and signal direction
10 BASE-T Cable
(*1)
SG
Station 1
Inverter
(*1)
2
0.2mm or more
SG
Station 2
Inverter
50
Inverter
RS-485 connector
SDA
SDB
RDA
RDB
SG
Terminating
resistor
(*2)
SG
Station n
Inverter