VEGA POINTRAC 31 Profibus PA User Manual
Page 52
52
11 Supplement
POINTRAC 31 • Profibus PA
43835-EN-131119
•
AI FB2 (OUT)
– Out value of the AI FB2 after scaling
•
AI FB3 (OUT)
– Out value of the AI FB3 after scaling
•
Free Place
– This module must be used if a value in the data telegram of the cyclical data traffic should not
be used (e.g. replacement of temperature and Additional Cyclic Value)
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
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.
Data format of the output signal
Byte4 Byte3 Byte2 Byte1 Byte0
Status
Value (IEEE-754)
Fig. 20: Data format of the output signal