VEGA VEGABAR 41 Profibus PA - Manual (Page 4)

4 VEGABAR 41 (Profibus PA)
Product description
1 Product description
1.1 Function and configuration
VEGABAR 41 process pressure transmitters
are efficient instruments with isolating system
for process pressure measurement. The
process pressure acts on the separating
diaphragm of the isolating diaphragm and is
transferred via the isolating liquid to a
ceramic-capacitive diaphragm. The pressure
effects via the diaphragm a capacitance
change within the measuring cell. This ca-
pacitance change is detected by an ASIC
(application specific integrated circuit) and
converted into a pressure-proportional signal
by the integrated electronic module with
microcontroller. In addition, the process tem-
perature is detected via a sensor element
and converted into a temperature-dependent
signal. Precise, high-resolution digital
processing of measurement data ensures
excellent technical data.
Isolating systems are used to protect the
measuring cell against corrosive products or
high temperatures. With the right choice of
the isolating liquid and diaphragm material,
systems with a temperature resistance up to
400°C are attainable.
The electronics module is powered by a
Profibus DP - PA segment coupler. The
measured pressure is transmitted via the
bus cable as digital signal to the processing
system and can be displayed on the
indicating module or the external indicating
instrument VEGADIS 10.
The following adjustment variants are
available:
- adjustment module directly on VEGABAR
- adjustment modules in external housing
(VEGADIS 10)
- via PC with adjustment software VEGA
Visual Operating (VVO)
The instrument profile of VEGABAR follows
the profile specification version 3.0. The
instrument master file (GSD) is available as
download on the homepage of VEGA
(www.vega-g.de).
1.2 Self-monitoring
To improve reliability, the functionality of im-
portant electronic components is continu-
ously checked, and internal parameters such
as sensor value, temperature and operating
voltage are closely monitored.
VEGABAR 41 with the ceramic CERTEC ®
measuring cell offers the advantage of con-
tinuous self-monitoring. The measuring and
reference capacitances of the measuring cell
constitute a predefined ratio over the entire
measuring range. Any deviation from these
data is a reliable indicator of a malfunction of
the measuring cell.
If errors or malfunctions are detected during
these routines, fault signals are triggered
according to the Profibus PA specification.