Mitsubishi Electric MELSEC iQ-R04ENCPU - Return Query Data (Sub-Function Code: 00 H)

22
3 MODBUS STANDARD FUNCTION DETAILS
3.8 Diagnostics (FC: 08H)
Return query data (sub-function code: 00H)
Operation description
Returns the contents of the request message without change.
Used to check if the network or the target device is operating normally. (Loopback test)
Request message format (from master to slave)
Response message format (from slave to master)
■ When completed successfully
The slave returns the request message received from the master as-is.
■ When completed with an error
(H) (L)
08H (0000H)
DataFunction code Sub-function code
Arbitrary data
88H
Data
Exception code
Function code