Mitsubishi Electronics FR-D720-008 Marine Battery User Manual


 
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Communication operation and setting
4.19.5 Mitsubishi inverter protocol (computer link communication)
(1) Communication
The communication specifications are given below.
(2) Communication procedure
∗1 If a data error is detected and a retry must be made, execute retry operation with the user program. The inverter comes to trip 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 trip if the number of consecutive data
errors reaches or exceeds the parameter setting.
You can perform parameter setting, monitoring, etc. from the PU connector of the inverter using the Mitsubishi inverter
protocol (computer link communication).
Item Description
Related
Parameter
Communication protocol Mitsubishi protocol (computer link) Pr. 549
Conforming standard EIA-485 (RS-485)
Number of connectable devices 1:N (maximum 32 units), setting is 0 to 31 stations Pr. 117
Communication
speed
PU connector Selected from among 4800/9600/19200 and 38400bps Pr. 118
Control procedure Asynchronous
Communication method Half-duplex
Communication
Character system ASCII (7 bits or 8 bits can be selected) Pr. 119
Start bit 1bit
Stop bit length 1 bit or 2 bits can be selected Pr. 119
Parity check Check (even, odd) or no check can be selected Pr. 120
Error check Sum code check
Terminator CR/LF (presence/absence selectable) Pr. 124
Waiting time setting Selectable between presence and absence Pr. 123
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 requested.)
2) After waiting for the waiting time
3) The inverter sends reply data to the computer
in response to the computer request.
4) After waiting for the inverter data processing
time
5) Answer from the computer in response to
reply data 3) of the inverter is transmitted.
(Even if 5) is not sent, subsequent
communication is made properly.)
When data is read
When data is written
1) 5)4)
3)2)
*1
*2
Computer
(Data flow)
Inverter
Computer
(Data flow)
Inverter
Time