JUMO mTRON T Manual page 34

3 Modbus protocol description
3.6.3 Write one bit
In the write bit function, the data blocks for the instruction and response are identical.
Instruction
Slave address
1 byte
Response
Slave address
1 byte
Example
In this example, manual mode for controller channel 1 of a controller module is to be activated
at Modbus address 2. To do this, it must logically be set to "1":
Instruction:
02
Slave
Response:
02
Slave
34
Function
0x05
1 byte
Function
0x05
1 byte
05 1C 80
Function Bit address
05 1C 80
Function Bit address
Bit address Bit value
2 bytes
Bit value xx = 00: bit is set to 0
Bit value xx = FF: bit is set to 1
Bit address Bit value
2 bytes
FF 00
Set bit to 1
FF 00
Set bit to 1
Checksum CRC
2 bytes 2 bytes
Checksum CRC
2 bytes 2 bytes
71 8A
CRC
71 8A
CRC