Delta Electronics DVP15MC11T, Operation Manual

Page: 552 / 601

Appendix B Modbus TCP Communication
B_
B.3 Exception Response Code in Modbus TCP

Modbus exception response codes that DVP15MC11T supports are shown in the table below.
Exception response code Indication
0x01 Unsupportive function code
0x02
Unsupportive Modbus address
0x03
Data length exceeds the range
B.4 Modbus Function Codes in Modbus TCP

Function code: 03 to read one single or multiple word register values

Request 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 Low byte
Byte7
Function code Single byte
Byte8
The start address of word registers to be
read
High byte
Byte9 Low byte
Byte10
The number of word registers
(Counted by Word)
High byte
Byte11 Low byte

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
Function code Single byte
B-3