VEGA VEGABAR 55 Foundation Fieldbus - climate compensated - Manual (Page 9)

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3 Product description
VEGABAR 55 • Foundation Fieldbus - climate compensated
39443-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 is supplied via the H1 Fieldbus. A two-wire cable according to
Fieldbus specification serves as carrier of both power and digital data
for multiple sensors. This cable can be operated in two versions:
•
via an H1 interface card in the control system and additional power
supply
•
via a Linking device with HSE (High speed Ethernet) and addi-
tional power supply according to IEC 61158-2
The DD (Device Descriptions) and CFF (capability files) necessary
for planning and configuration of your FF (Foundation Fieldbus) com-
munication network are available in the download area of the VEGA
homepage www.vega.com under "Services - Downloads - Software
- Foundation Fieldbus". The appropriate certificates are also available
there. A CD with the appropriate files and certificates can be ordered
via e-mail under [email protected] or by phone from one of the
VEGA agencies under the order number "DRIVER.S".
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.
Scope of this operating
instructions manual
Application area
Functional principle
Power supply and bus
communication
DD/CFF