VEGA VEGABAR 40 Profibus PA - Manual (Page 4)

4 VEGABAR 40 (Profibus PA)
Product description
1 Product description
1.1 Function and configuration
VEGABAR 40 process pressure transmitters
are efficient instruments for process pres-
sure measurement. As pressure sensor
element, the dry ceramic-capacitive measur-
ing cell CERTEC
® is used. The process pres-
sure 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 oscillator 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.
The electronics module is powered by a
Profibus DP - PA segment coupler. The
measured pressure is transmitted via the
bus cable as a digital signal to the process-
ing system and can be displayed on the
indicating module or the external indicating
instrument VEGADIS 10.
The following adjustment variants are avail-
able:
- 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 in-
strument 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 40 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.