Hamilton Sundstrand Company Fuel Metering Valves XVG - Manual (Page 8)

Example: Request to read holding registers 108 - 110
Request Response
01 03 00 6B 00 03 74 17 01 03 06 02 2B 00 00 00 64 05 7A
Slave Address 01 Slave Address 01
Function 03 Function 03
Starting Address Hi 00 Byte Count 06
Starting Address Lo 6B Register Value Hi (108) 02
Number of Registers Hi 00 Register Value Lo (108) 2B
Number of Registers Lo 03 Register Value Hi (109) 00
CRC 7417 Register Value Lo (109) 00
Register Value Hi (110) 00
Register Value Lo (110) 64
CRC 057A
Table 6: Modbus Function 03 - Example
7.4.2 Write Single Register (0x06)
Request message:
SLAVE ADDRESS + FUNCTION CODE + REGISTER ADDRESS + REGISTER
VALUE + CRC
Request Length Valid Value
Slave Address 1 Byte 0 to 247
Function code 1 Byte 0x06
Register Address 2 Bytes 0x0000 to 0xFFFF
Register Value 2 Bytes 0x0000 to 0xFFFF
CRC 2 Bytes 0x0000 to 0xFFFF
Table 7: Modbus Function 06 - Request Message
Response message:
SLAVE ADDRESS + FUNCTION CODE + REGISTER ADDRESS + REGISTER
VALUE + CRC
Response Length Valid Value
Slave Address 1 Byte 0 to 247
Function code 1 Byte 0x06
Register Address 2 Bytes 0x0000 to 0xFFFF
Register Value 2 Bytes 0x0000 to 0xFFFF
CRC 2 Bytes 0x0000 to 0xFFFF
Table 8: Modbus Function 06 - Response Message
8