GT200 series general purpose inverter instruction manual
These two parts form the application protocol data unit of Modbus, and the application
protocol data unit in the following refers to these two parts. Description on frame format in
the following takes RTU mode as an example, and ASCII mode application layer protocol
data unit’s length needs to be doubled.
Read inverter parameters’ application layer protocol data unit as follows:
Request format is as follows:
Application Layer Protocol
Data Unit
Data Length(Bytes)
Value or Range
Function code
1
0x03
Start register address
2
0x0000
～
0xFFFF
Register number
2
0x0001
～
0x0004
Response format is as follows:
Application Layer Protocol
Data Unit
Data Length(Bytes)
Value or Range
Function code
1
0x03
Read bytes
1
2* Register number
Read contents
2* Register number
If operation request fails, response should be error codes and abnormal codes. Error code
is equal to (function code
＋
0x80), and abnormal code indicates error reasons. Abnormal
codes are listed as follows:
Abnormal Code
Abnormal Code Significance
0x1
Illegal function code.
0x2
Illegal register address.
0x3
Data error, data exceeds upper limit or lower limit.
0x4
Slave operation fails (including data within the range of upper
limit and lower limit, but errors caused by invalid data)
0x5
Command valid, under transaction, mainly used in storing data to
non-volatile storage.
0x6
Slave is busy, please try later, mainly used in storing data to
non-volatile storage.
0x18
Information frame error: Including information length error and
check error.
0x20
Parameter unable to be modified.
0x22
Parameters are protected by password.
Modify single inverter parameter’s application layer protocol data unit, as follows:
Request format is as follows:
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