Communication Protocol
111
3013H Length value R
3014H External counter input R
3015H Reserved R
3016H Device code R
Fault info
address
5000H
This address stores the fault type of
inverter. The meaning of each value
is same as P7.15.
R
ModBus
communication
fault info address
5001H
0000H: No fault
0001H: Wrong password
0002H: Command code error
0003H: CRC error
0004H: Invalid address
0005H: Invalid data
0006H: Parameter change invalid
0007H: System locked
0008H: Busy (EEPROM is storing)
R
The above shows the format of the frame. Now we will introduce the Modbus command
and data structure in details, which is called protocol data unit for simplicity. Also MSB
stands for the most significant byte and LSB stands for the least significant byte for the
same reason. The description below is data format in RTU mode. The length of data unit
in ASCII mode should be doubled.
Protocol data unit format of reading parameters:
Request format:
Protocol data unit
Data length(bytes) Range
Command 1 0x03
Data Address 2 0~0xFFFF
Read number 2 0x0001~0x0010
Reply format (success):
Protocol data unit
Data length(bytes) Range
Command 1 0x03
Returned byte number 2 2* Read number
Content 2* Read number
If the command is reading the type of inverter (data address 0x3016), the content value in
reply message is the device code:
The high 8 bit of device code is the type of the inverter, and the low 8 bit of device code is
the sub type of inverter.
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