Mitsubishi Electric FR-D720S SC EC Instruction Manual page 346

Communication operation and settings
Connection with RS485 computer
● Wiring of one RS485 computer and one inverter
Computer side terminals
Fig. 6-101: Connection to an inverter
● Wiring of one RS485 computer and "n" inverters (several inverters)
Receive
Send
Fig. 6-102: Connection to several inverter
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.
The inverters may be affected by reflection depending on the transmission speed or
transmission distance. If this reflection hinders communication, provide a terminating
resistor. If the PU connector is used to make a connection, use a distributor since a
terminating resistor cannot be fitted. Connect the terminating resistor to only the inverter
remotest from the computer. (Terminating resistor: 100Ω)
NOTE Do not use pins No. 2, 8 of the FR-A5CBL cable. (Refer to page 6-193.)
6 - 196
Receive data
Receive data
Send data
Send data
Signal ground
PC
Cable connection and signal direction
0,2 mm² or more
Station 0 Station 1
Parameter
Inverter
PU connector
I001938E
Terminating
resistor
Station n
I001939E