Communication Procedure - Mitsubishi Electric 800 Series Instruction Manual

4.4.2

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.)

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.
Computer
↓ (Data flow)
Inverter a
Inverter
∗1
↓ (Data flow)
When data is written
Computer
When data is read
∗2
d e
b c
Time
PARAMETER
4
35