VEGA VEGABAR 82 Modbus and Levelmaster protocol - Operating Instructions - Manual (Page 72)

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10 Supplement
VEGABAR 82 • Modbus and Levelmaster protocol
46294-EN-131107
Parameter Length Code/Data
Start Address 2 Bytes 2*N
Register Value N*2 Bytes Data
FC4 Read Input Register
With this command, any number (1-127) of input registers can be read out. The start register, from
which the readout should start, and the number of registers are transmitted.
Request:
Parameter Length Code/Data
Function Code 1 Byte 0x04
Start Address 2 Bytes 0x0000 to 0xFFFF
Number of Registers N*2 Bytes 1 to 127 (0x7D)
Response:
Parameter Length Code/Data
Function Code 1 Byte 0x04
Start Address 2 Bytes 2*N
Register Value N*2 Bytes Data
FC6 Write Single Register
With this function code an individual holding register can be written.
Request:
Parameter Length Code/Data
Function Code 1 Byte 0x06
Start Address 2 Bytes 0x0000 to 0xFFFF
Number of Registers 2 Bytes Data
Response:
Parameter Length Code/Data
Function Code 1 Byte 0x04
Start Address 2 Bytes 2*N
Register Value 2 Bytes Data
FC8 Diagnostics
With this function code different diagnostic functions can be triggered or diagnostic values read out.
Request:
Parameter Length Code/Data
Function Code 1 Byte 0x08