Appendix B Communication Protocol
Shenzhen Hpmont Technology Co., Ltd
―
156
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HD20 Series Inverters User Manual
⑥
Function parameters management (function code 0x42)
The inverter function parameters management includes reading the upper/lower limit of
parameters, to read parameter characteristics, to read the biggest intergroup index of function
parameters, to read the previous and next function parameter group number, to read index of the
parameter being displayed and to display next status parameter. The parameter characteristics
include read-write ability, parameter units and scaling. These commands are used to adjust
remotely inverter parameters.
The command and response frames of the function parameters management are as follows:
Protocol data unit
Length of data (byte)
Range
Command frame
Address
1
0
－
247, 0 is broadcast
address
Function code
1
0x42
Subfunction code
2
0x0000
－
0x0008
Data
2
Depends on inverter model
CRC /LRC checking
2/1
Response frame
Address
1
1
－
247
Function code
1
0x42
Subfunction code
2
0x0000
－
0x0008
Data
2
0x0000
－
0xFFFF
CRC /LRC checking
2/1
On condition that the operation command fails, response is fault code and exception code.
Subfunction under function parameter management:
Subfunction
code
Data (command)
Data (response)
Subfunction meanings
0x0000
The function parameter
group no. and intergroup
index occupy the higher
and lower bytes
respectively.
The upper limit of function
parameter.
To read the upper limit of
function parameter.
(Unsupported this operation of
reading upper limit in status
and control parameters)
0x0001
The function parameter
group no. and intergroup
index occupy the higher
and lower bytes
respectively.
The lower limit of function
parameter.
To read the lower limit of
function parameter.
(Unsupported this operation of
reading lower limit in status
and control parameters)
0x0002
The function parameter
group no. and intergroup
index occupy the higher
and lower bytes
respectively.
Characteristics of function
parameters and see the table
of parameter’s characteristics
for more details
To read the characteristic of
function parameters.
(Unsupported this operation of
reading characteristic in
control parameters)
0x0003
The function parameter
group no. occupies the
higher byte, and the
lower byte is “00”.
The max. value of intergroup
index.
To read the max value of
intergroup index.
0x0004
The function parameter
Next function parameter group To read next function