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3  MODBUS STANDARD FUNCTION DETAILS
3.5  Write Single Coil (FC: 05H)
3.5 Write Single Coil (FC: 05H)
Operation description
Writes a value (ON/OFF) to one coil.
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) (H) (L)
05H
FF00H: ON
0000H: OFF
Coil number specification
Data
ON/OFF specification
Function code
(0000H to FFFFH)
85H
Data
Exception code
Function code