VEGA VEGABAR 55 Profibus PA - climate compensated - Manual (Page 9)

9
3 Product description
VEGABAR 55 • Profibus PA - climate compensated
39442-EN-130321
This operating instructions manual applies to the following instrument
versions:
•
Software from 3.82
3.2 Principle of operation
The VEGABAR 55 - climate compensated is a pressure transmitter
for use in the chemical, food processing and pharmaceutical industry
under difficult climatic conditions (cold medium and warm humid
environment).
Depending on the version, the pressure transmitter is used for meas-
urement of level, gauge pressure or vacuum. Measured products are
gases, vapours and liquids also with higher temperatures.
Measuring unit is the METEC ® measuring cell. This measuring cell
consists of the ceramic-capacitive CERTEC ® absolute pressure
measuring cell and a special temperature-compensated isolating
system. The process pressure causes a capacitance change in the
measuring cell via the ceramic diaphragm. This change is converted
into an electrical signal, compared with an integrated reference pres-
sure measurement and outputted as measured value via the output
signal.
The hydrostatic pressure of the product or the process pressure
causes a capacitance change in the measuring cell via the metallic
process diaphragm and the isolating liquid. This change is converted
into a corresponding output signal.
Power supply via the Profibus DP/PA segment coupler or VEGALOG
571 EP cards. A two-wire cable according to Profibus specification
serves as carrier of both power and digital data transmission for
multiple sensors. The instrument profile of VEGABAR 55 corresponds
to profile specification version 3.0.
The backlight of the display and adjustment module is powered by the
sensor. Prerequisite is a certain level of operating voltage.
The data for power supply are specified in chapter "Technical data".
The optional heating requires its own operating voltage. You can find
details in the supplementary instructions manual "Heating for display
and adjustment module".
This function is generally not available for approved instruments.
The GSD (instrument master files) and bitmap files necessary for
planning your Profibus-DP-(PA) communication network are available
from the download section on the VEGA homepage www.vega.com
under "Services - Downloads - Software - Profibus". There you can
also find the appropriate certificates. In a PDM environment, an EDD
(Electronic Device Description) is also required to enable the full
range of sensor functions (also available as a download).A CD with
the appropriate files can be ordered via e-mail under [email protected].
com or by phone from one of the VEGA agencies under the order
number "DRIVER.S".
Scope of this operating
instructions manual
Application area
Functional principle
Power supply and bus
communication
GSD/EDD