VEGA VEGABAR 82 Modbus and Levelmaster protocol - Operating Instructions - Manual (Page 69)

69
10 Supplement
VEGABAR 82 • Modbus and Levelmaster protocol
46294-EN-131107
General configuration of the host
The data exchange with status and variables between field device and host is carried out via
register. For this, a configuration in the host is required. Floating point numbers with short prevision
(4 bytes) according to IEEE 754 are transmitted with individually selectable order of the data bytes
(byte transmission order). This "Byte transmission order" is determined in the parameter "Format
Code". Hence the RTU knows the registers of the VEGABAR 82 which must be contacted for the
variables and status information.
Format Code Byte transmission order
0 ABCD
1 CDAB
2 DCBA
3 BADC
10.3 Modbus register
Holding Register
The Holding registers consist of 16 bit. They can be read and written. Before each command, the
address (1 byte), after each command, a CRC (2 byte) is sent.
Register Name Register Num-
ber
Type Configurable
Values
Default Value Unit
Address 200 Word 1 … 255 246 -
Baud Rate 201 Word 1200, 2400,
4800, 9600,
19200
9600 -
Parity 202 Word 0 = None, 1 =
Odd, 2 = Even
0 -
Stopbits 203 Word 1 = None, 2 =
Two
1 -
Delay Time 206 Word 10 … 250 50 ms
Byte Oder (Float-
ing point format)
3000 Word 0, 1, 2, 3 0 -
Input register
The input registers consist of 16 bits. They can only be read out. Before each command, the ad-
dress (1 byte) is sent, after each command a CRC (2 bytes) is sent.
PV, SV, TV and QV can be adjusted via the sensor DTM.
Register Name Register Number Type Note
Status 100 DWord Bit 0: Invalid Measurement Value PV
Bit 1: Invalid Measurement Value SV
Bit 2: Invalid Measurement Value TV
Bit 3: Invalid Measurement Value QV
PV Unit 104 DWord Unit Code
PV 106 Primary Variable in Byte Order CDAB