Delta DVP-15MC Series - A.5 Introduction to Modbus Function Codes

DVP-15MC Series Motion Controller Operation Manual
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A.5 Introduction to Modbus Function Codes
 Function code 03 reads one single or multi word register values
 Data structure of a request message:
Byte NO. Name Byte
Byte0
Modbus ID Single byte
Byte1
Function code Single byte
Byte2
Read the start address of word registers in DVP-
15MC series motion controller
High byte
Byte3
Low byte
Byte4
Read the number of addresses of word registers
in DVP-15MC series motion controller
(Counted by Word)
High byte
Byte5
Low byte
Byte6
Low byte of CRC check sum
Low byte
Byte7
High byte of CRC check sum
High byte
 Data structure of a response message:
Byte NO. Name Byte
Byte0
Modbus ID Single byte
Byte1
Function code Single byte
Byte2
Read the number of addresses of word registers
in DVP-15MC series motion controller
(Counted by Byte)
Single byte
Byte3
The address content of the word register in DVP-
15MC series motion controller
High byte
Byte4
Low byte
…
The address content of the word register in DVP-
15MC series motion controller
High byte
…
Low byte
Byte n
The address content of the word register in DVP-
15MC series motion controller
High byte
Byte n+1
Low byte
Byte n+2
Low byte of CRC check sum
Low byte
Byte n+3
High byte of CRC check sum
High byte
 Data structure of an exception response message:
Byte NO. Name Byte
Byte0
Modbus ID Single byte
Byte1
16#80+ function code Single byte
Byte2
Exception response code Single byte
Byte3
Low byte of CRC check sum Low byte
Byte4
High byte of CRC check sum High byte