Mitsubishi Inverter Protocol (Computer Link Communication); Communication Specifications - Mitsubishi FR-A800 Instruction Manual

5.15.5
Mitsubishi inverter protocol (computer link
communication)
Parameter settings and monitoring are possible by using the Mitsubishi inverter protocol (computer link communication)
via inverter PU connector and the RS-485 terminals.
Communication specifications
• The communication specifications are given below.
Item
Communication protocol
Conforming standard
Connectable units
PU connector
Communication
Speed
RS-485 terminals
Control procedure
Communication method
Character system
Start bit
Stop bit length
Communication
specifications
Parity check
Error check
Terminator
Waiting time setting
Communication procedure
• Data communication between the computer and inverter is made in the following procedure.
(a) Request data is sent from the computer to the inverter. (The inverter will not send data unless requested.)
(b) After waiting for the waiting time,
(c) The inverter sends reply data to the computer in response to the computer request.
(d) After waiting for the inverter data processing time,
(e) An answer from the computer in response to reply data (c) of the inverter is transmitted. (Even if (e) is not sent,
subsequent communication is made properly.)
Computer
Inverter
Inverter
Computer

If a data error is detected and a retry must be made, perform retry operation with the user program. The inverter trips if the number of
consecutive retries exceeds the parameter setting.

On receipt of a data error occurrence, the inverter returns reply data (c) to the computer again. The inverter trips if the number of consecutive
data errors reaches or exceeds the parameter setting.
Mitsubishi protocol (computer link)
EIA-485 (RS-485)
1:N (maximum 32 units), setting is 0 to 31 stations
Selected among 4800/9600/19200/38400 bps
Selected among 300/600/1200/2400/4800/9600/19200/38400/38400/
57600/76800/115200 bps
Asynchronous system
Half-duplex system
ASCII (7 bits or 8 bits can be selected.)
1 bit
1 bit or 2 bits can be selected.
Check (at even or odd numbers) or no check can be selected.
Sum code check
CR/LF (presence/absence selectable)
Selectable between presence and absence
↓ (Data flow)
a
∗1
↓ (Data flow)
When data is written
(N) Operation via communication and its settings
Description
When data is read
∗2
d e
b c
Related
Parameter
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
Time
565
PARAMETERS
5
GROUP
N