3 modbus register, Parameters for the bus communication, General configuration of the host – VEGA VEGABAR 86 Modbus and Levelmaster protocol - Operating Instructions User Manual

Page 63: Holding register

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63

10 Supplement

VEGABAR 86 • Modbus and Levelmaster protocol

46296-EN-131107

Parameters for the bus communication

The VEGABAR 86 is preset with the default values:

Parameter

Configurable Values

Default Value

Baud Rate

1200, 2400, 4800, 9600, 19200

9600

Start Bits

1

1

Data Bits

7, 8

8

Parity

None, Odd, Even

None

Stop Bits

1, 2

1

Address range Modbus

1 … 255

246

Start bits and data bits cannot be modified.

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 86 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

-

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