Mitsubishi Electric MR-JE-C Series Instruction Manual page 40

3. Modbus/TCP
(2) Usage example
The following shows a setting example of when the diagnosis function is used.
Query Message
Transaction Protocol
Length Field
Identifier Identifier
16 bits 0000h
Set the following values to each Query Message.
Message field
Transaction Identifier
Protocol Identifier
Length Field
Unit Identifier
Function
Sub Function
Data
Response Message
Transaction Protocol
Length Field
Identifier Identifier
16 bits 0000h
The following shows the information in each Response Message.
Message field
Transaction Identifier
Protocol Identifier
Length Field
Unit Identifier
Function
Sub Function
Data
Unit
Function
Identifier
0006h FFh 08h
Set any value.
Set "0000h".
Set "0006h".
Set "FFh".
Set "08h".
Set "0000h".
When setting 1234h, set values as follows:
H: "12h"
L: "34h"
Unit
Function
Identifier
0006h FFh 08h
Transaction Identifier received from the client (controller) is copied and returned.
The value "0000h" is returned.
The byte length from Unit Identifier to Data is returned.
Unit Identifier received from the client (controller) is copied and returned.
When the message was received without errors, "08h" is returned.
The value "0000h" is returned.
The value "1234h" set in the Query Message is returned.
H: "12h"
L: "34h"
Sub Function
H L H
00h 00h 12h
Description
Sub Function
H L H
00h 00h 12h
Description
3 - 7
Data
L
34h
Data
L
34h