VEGA VEGABAR 87 Modbus and Levelmaster protocol - Operating Instructions - Manual (Page 65)

65
10 Supplement
VEGABAR 87 • Modbus and Levelmaster protocol
46297-EN-131107
Unit Code Measurement Unit
47 Inches
48 Centimeters
49 Millimeters
111 Cubic Yards
112 Cubic Feet
113 Cubic Inches
10.4 Modbus RTU commands
FC3 Read Holding Register
With this command, any number (1-127) of holding 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 0x03
Start Address 2 Bytes 0x0000 to 0xFFFF
Number of Registers 2 Bytes 1 to 127 (0x7D)
Response:
Parameter Length Code/Data
Function Code 1 Byte 0x03
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