UF_ModbusTCP_Manual
UFACTORY ModbusTCP User Instructions
Notice:
Communication complies with standard Modbus TCP protocol
Data transmission uses Big-endian method, for example transmission order of data 0x1234 is: 0x12, 0x34
Different register addresses hold different specific contents, details refer to the appendix
Make sure to access the pre-defined register address(refer to appendix),or there will be exception in response
Supported Modbus TCP function codes:
Coil register(1 bit)
0x01: Read multiple coil registers,each bit in responded data section represents the value of each one register:
0x05: Write single coil, according to Modbus protocol, specified data can only be 0xFF00 or 0x0000,for wriring 1 or 0 to the register.
0x0F: Write multiple coil registers
Discrete input register (1 bit)
0x02: Read multiple discrete input registers
Holding register (16 bit)
0x03: Read multiple holding registers
0x06: Write single holding register
0x10: Write multiple holding registers
0x16: Mask write single holding register
0x17: Read and Write multiple holding registers
Input register (16 bit)
0x04: Read multiple input registers
Exception code explanation
0x01: Illegal/Unsuppported function code
0x02: Illegal target address
0x03: Exception of requested data
Appendix
Coil Registers (single bit access, READ/WRITE)
Discrete Input Registers (single bit access, READ only)
Holding Registers (16 bit access, READ/WRITE)
Input Registers (16 bit access, READ only)
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