(Pr. 117, Pr. 118, Pr. 120, Pr. 122, Pr. 343, Pr. 549)
Using the Modbus RTU communication protocol, communication operation or parameter setting
can be performed from the PU connector of the inverter.
Pr. No. Name
tion parity check
tion check time
Stop mode selec-
tion at communi-
The above parameter can be set when Pr. 160 "User group read selection" = 0.
When Modbus-RTU communication is performed from the master with address 0 (station
number 0) set, broadcast communication is selected and the inverter does not send a
response message. When response from the inverter is necessary, set a value other than
"0" (initial value is 0) in Pr. 117 "PU communication station number". Some functions are
invalid for broadcast communication. (Refer to page 6-254.)
When "1" (Modbus-RTU protocol) is set in Pr. 549 and "384" (38400bps) in Pr. 118, parameter
unit (FR-PU04/FR-PU07) is disabled. When using the parameter unit (FR-PU04/FR-PU07),
change parameter using the operation panel.
When using the Modbus-RTU protocol, set Pr. 549 "Protocol selection" to "1".
When PU connector is selected as NET mode operation source (when Pr. 550 "NET mode
operation command source selection" = 2 or 9999 (initial value) without communication
option), Modbus RTU communication operation can be performed. (Refer to section 6.19.2).
No reply to the master
Inverter station number specification
Set the inverter station numbers when two or more invert-
ers are connected to one personal computer.
The setting value × 100 equals the communication speed.
(Example: 9600bps if 96)
Without parity check
Stop bit length 2bit
With odd parity check
Stop bit length 1bit
With even parity check
Stop bit length 1bit
RS-485 communication can be made. Note that a commu-
nication fault (E.PUE) occurs as soon as the inverter is
switched to the operation mode with command source.
Communication check (signal loss detection) time interval
If a no-communication state persists for longer than the
permissible time, the inverter will come to trip (depends
on Pr. 502).
No communication check (signal loss detection)
Displays the number of communication errors during
Modbus-RTU communication (reading only)
Mitsubishi inverter (computer link) protocol
Communication operation and setting
Parameters referred to
6 - 251