4 comandi rtu modbus, Fc3 read holding register – VEGA VEGABAR 82 Modbus and Levelmaster protocol - Operating Instructions Manuale d'uso

Pagina 73

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73

10 Appendice

VEGABAR 82 • Protocollo Modbus e LevelMaster

46294-IT

-131205

Register Name

Register Number

Type

Note

PV

2202

DWord

Primary Variable in Byte Order BACD (Middle Endian)

SV

2204

DWord

Secondary Variable in Byte Order BACD (Middle En-

dian)

TV

2206

DWord

Third Variable in Byte Order BACD (Middle Endian)

QV

2208

DWord

Quarternary Variable in Byte Order BACD (Middle En-

dian)

Unit Codes for Register 104, 108, 112, 116

Unit Code

Measurement Unit

32

Degree Celsius

33

Degree Fahrenheit

40

US Gallon

41

Liters

42

Imperial Gallons

43

Cubic Meters

44

Feet

45

Meters

46

Barrels

47

Inches

48

Centimeters

49

Millimeters

111

Cubic Yards

112

Cubic Feet

113

Cubic Inches

10.4 Comandi RTU Modbus

FC3 Read Holding Register

Tramite questo comando è possibile leggere un numero qualsiasi (1-127) di holding register. Vengo-

no trasmessi il registro iniziale, a partire dal quale va effettuta la lettura, e il numero di registri.
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:

Parametro

Lunghezza

Code/Data

Function Code

1 Byte

0x03

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