15 Appendix B - Modbus communication example
15 Appendix B - Modbus communication example
03 (0x03) Read holding register
Request Response
Slave address
1 byte
Slave address
1 byte
Function code
1 byte
Function code
1 byte
Starting address
Hi
1 byte
Byte count
1 byte
Starting address
Lo
1 byte
Register Hi
1 byte
No. of points Hi
1 byte
Register Lo
1 byte
No. of points Lo
1 byte
:
:
CRC
2 bytes
Register Hi
1 byte
Register Lo
1 byte
CRC
2 bytes
05 (0x05) Write single coil
Request Response
Slave address
1 byte
Slave address
1 byte
Function code
1 byte
Function code
1 byte
Coil address Hi
1 byte
Coil address Hi
1 byte
Coil address Lo
1 byte
Coil address Lo
1 byte
Data Hi
1 byte
Data Hi
1 byte
Data Lo
1 byte
Data L
1 byte
CRC
2 bytes
CRC
2 bytes
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