beautypg.com

6 examples of telegram configuration, 7 data format of the output signal – VEGA VEGAPULS 65 (≥ 2.0.0 - ≥ 4.0.0) Profibus PA User Manual

Page 62

background image

62

11 Supplement

VEGAPULS 65 • Profibus PA

36517-EN-121011

A maximum of three modules can be active. By means of the configuration software of the Profibus

master you can determine the configuration of the cyclical data telegram with these modules. The

procedure depends on the respective configuration software.

Note:

The modules are available in two versions:

Short for Profibus master supporting only one "Identifier Format" byte, e.g. Allen

Bradley

Long for Profibus master only supporting the "Identifier Format" byte, e.g. Siemens

S7-300/400

11.6 Examples of telegram configuration

In the following you will see how the modules can be combined and how the appendant data tel-

egram is structured.
Example 1

AI FB1 (OUT)

AI FB2 (OUT)

AI FB3 (OUT))

Byte-

No.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

For-

mat

IEEE-754-Floating point

value

Sta-

tus

IEEE-754-Floating point

value

Sta-

tus

IEEE-754-Floating point

value

Sta-

tus

Value

AI FB1 (OUT)

AI

FB1

AI FB2 (OUT)

AI

FB2

AI FB3 (OUT)

AI

FB3

Example 2

AI FB1 (OUT)

Free Place

Free Place

Byte-No.

1

2

3

4

5

Format

IEEE-754-Floating point value

Status

Value

AI FB1 (OUT)

AI FB1

Note:

Bytes 6-15 are not used in this example.

11.7 Data format of the output signal

Byte4 Byte3 Byte2 Byte1 Byte0

Status

Value (IEEE-754)

Fig. 47: Data format of the output signal

The status byte corresponds to profile 3.02 "Profibus PA Profile for Process Control Devices" coded.

The status "Measured value OK" is coded as 80 (hex) (Bit7 = 1, Bit6 … 0 = 0).
The measured value is transferred as a 32 bit floating point number in the IEEE-754 format.