4.20.2 Initial settings and specifications of RS-485 communication
(Pr. 117 to Pr. 120, Pr. 123, Pr. 124, Pr. 549)
The following parameters are used to perform required settings for RS-485 communication between the inverter and
personal computer.
Use PU connector of the inverter for communication.
You can perform parameter setting, monitoring, etc. using Mitsubishi inverter protocol or Modbus-RTU protocol.
To make communication between the personal computer and inverter, setting of the communication specifications
must be made to the inverter in advance.
Data communication cannot be made if the initial settings are not made or there is any setting error.
Parameter
Name
Number
PU communication
117
station number
118
PU communication speed
PU communication stop
119
bit length
PU communication parity
120
check
PU communication
123
waiting time setting
PU communication CR/LF
124
selection
549
Protocol selection
The above parameters can be set when Pr. 160 Extended function display selection = "0". (Refer to page 197)
When "1" (Modbus-RTU protocol) is set in Pr. 549, the setting range within parentheses is applied.
NOTE
Always reset the inverter after making the initial settings of the parameters. After you have changed the
communication-related parameters, communication cannot be made until the inverter is reset.
Communication operation and setting
Initial
Setting Range
Value
0 to 31 (0 to 247)
0
192
48, 96, 192, 384
0
1
1
10
11
0
2
1
2
0 to 150ms
9999
9999
0
1
1
2
0
0
1
Description
Inverter station number specification
Set the inverter station numbers when two or more
inverters are connected to one personal computer.
Communication speed
The setting value X 100 equals to the
communication speed.
Example)19200bps if 192
Stop bit length
1 bit
8 bits
2 bits
1 bit
7 bits
2 bits
Without parity check
With odd parity check
With even parity check
Set the waiting time between data transmission to
the inverter and response.
Set with communication data.
Without CR/LF
With CR
With CR/LF
Mitsubishi inverter (computer link operation) protocol
Modbus-RTU protocol
Data length
4
221