Mitsubishi Inverter Protocol (Computer Link Communication) - Mitsubishi Electric FR-A700 Instruction Manual

4.24.5 Mitsubishi inverter protocol (computer link communication)

You can perform parameter setting, monitor, etc. from the PU connector or RS-485 terminals of the inverter using
the Mitsubishi inverter protocol (computer link communication).
(1) Communication specifications
⋅ The communication specifications are given below.
Item
Communication protocol
Conforming standard
Number of inverters connected
PU connector
Communication
speed
RS-485 terminal
Control protocol
Communication method
Character system
Start bit
Stop bit length
Communication
specifications
Parity check
Error check
Terminator
Waiting time setting
(2) Communication procedure
Computer
(Data flow)
Inverter 1)
Inverter
*1
(Data flow)
Computer
*1 If a data error is detected and a retry must be made, execute retry operation with the user program. The inverter comes to an alarm stop if the
number of consecutive retries exceeds the parameter setting.
*2 On receipt of a data error occurrence, the inverter returns "reply data 3)" to the computer again. The inverter comes to an alarm stop if the number
of consecutive data errors reaches or exceeds the parameter setting.
1:N (maximum 32 units), setting is 0 to 31 stations
Selected from among 4800/9600/19200 and 38400bps
Can be selected from 300, 600, 1200, 2400, 4800, 9600, 19200 and
ASCII (7 bits or 8 bits can be selected)
Check (even, odd) or no check can be selected
CR/LF (presence or absence can be selected)
Selectable between presence and absence
When data is read
*2
4) 5)
2) 3)
When data is written
Communication operation and setting
Description
Mitsubishi protocol (computer link)
EIA-485 (RS-485)
38400bps
Asynchronous system
Half-duplex system
1bit
1 bit or 2 bits can be selected
Sum code check
⋅ Data communication between the computer and
inverter is made in the following procedure.
1) Request data is sent from the computer to the
inverter. (The inverter will not send data unless
Time
requested.)
2) After waiting for the waiting time
3) The inverter sends return data to the computer in
response to the computer request.
4) After having waited for the time taken for inverter
processing
5) Answer from computer in response to reply data
3) is sent. (Even if 5) is not sent, subsequent
communication is made properly.)
Related
Parameters
Pr. 551
⎯
Pr. 117
Pr. 331
Pr. 118
Pr. 332
⎯
⎯
Pr. 119
Pr. 333
⎯
Pr. 119
Pr. 333
Pr. 120
Pr. 334
⎯
Pr. 124
Pr. 341
Pr. 123
Pr. 337
4
329