Delta Electronics DVP15MC11T - Page 556

Appendix B Modbus TCP Communication
B
_
Byte NO. Name Byte
Byte6
Modbus ID Single byte
Byte7
Function code Single byte
Byte8
The start address of word registers where to write
values
High byte
Byte9
Low byte
Byte10
The number of word registers where to write values.
(Counted by Word)
High byte
Byte11
Low byte
 Exception response message data structure:
Byte NO. Name Byte
Byte0
Transaction identifier
High byte
Byte1
Low byte
Byte2
Protocol identifier
High byte
Byte3
Low byte
Byte4
Modbus data length
High byte
Byte5
Low byte
Byte6
Modbus ID Single byte
Byte7
0x80+ function code Single byte
Byte8
Exception response code Single byte
Note:
How many bytes of data in a response message depend on the number of read register addresses in
DVP15MC11T in the request message. So the value of n in Byte n in the response message can be
calculated through reading the number of register addresses in DVP15MC11T.
 Example
To write 0x0100 and 0x0200 to the addresses 0x0000 and 0x0001 in DVP15MC11T via
function code 06.
0x0000 and 0x0001 are the Modbus addresses of %MW0 and %MW1 in DVP15MC11T
respectively.
Request message: 00 00 00 00 00 0B 01 10 00 00 00 02 04 01 00 02 00
Response message: 00 00 00 00 00 06 01 10 00 00 00 02
 Function code: 0x02 to read multiple bit register values
 Request message data structure:
Byte NO. Name Byte
Byte0
Transaction identifier
High byte
Byte1
Low byte
B-7