VEGA VEGAPULS 45 Profibus PA - Manual (Page 7)

VEGAPULS 42, 44 and 45 – Profibus PA 7
24908-EN-041227
Product description
Master-Class 1
is the actual automation system or the proc-
ess control computer or the PLC that en-
quires and processes all measured values.
Master-Class 2
One or several Master-Class 2 can operate in
a Profibus network. As a rule, Master-Class 2
devices are engineering, adjustment or visu-
alisation stations. The VEGA adjustment soft-
ware VVO (VEGA Visual Operating) operates
as Master-Class 2 participant on the DP bus
and can work on an engineering PC, on an
adjustment PC or on the process control
computer and can access any VEGA sensor
on the PA level.
Instrument master file
A so-called GSD file is delivered with every
VEGAPULS Profibus sensor. This file is re-
quired to integrate the sensor into the bus
system. The GSD (instrument master file)
contains, beside the sensor name and the
manufacturer, the sensor-specific communi-
cation parameters which are necessary for a
stable integration of the sensor in the bus.
Load the GSD file belonging to the sensor
into your bus configuration program. If the
GSD file is not available, it can be
downloaded from the VEGA homepage: http:/
/www.vega.com.
Do not confuse the GSD file with the EDD
(Electronic Device Description), a file which
may in some cases be necessary for the
PDM environment (this can be also found on
the VEGA homepage).
1.4 Adjustment
Every measuring set-up is unique. For that
reason, every radar sensor needs beside
the adjustment some basic information on the
application and the environment, e.g. which
level means "empty“ and which level "full“.
Beside this "empty and full adjustment“, many
other settings and adjustments are possible
with VEGAPULS radar sensors. The output of
echo curves or the calculation of vessel
linearisation curves by means of vessel di-
mensions are only two examples.
Profibus adjustment structure
In the Profibus environment, there are differ-
ent adjustment concepts and adjustment
tools which often differ considerably from
manufacturer to manufacturer. From the us-
er’s point of view, the ideal solution would be
a manufacturer-independent adjustment
program which could be operated directly on
the Profibus DP/PA, on the sensor, as well as
at any system node (e.g. an engineering
station or process control center).
In the past, only the program „SIMATIC
PDM“, based on the HART
® adjustment
structure, could fulfil this wish (though with
the limitations common to HART
® ). As with
HART ® , the availability of an instrument-spe-
cific database for a comprehensive adjust-
ment with PDM (Process Device Managing)
is a requirement. Otherwise, only the basic
instrument functions, such as basic adjust-
ment, are available. In the PDM environment,
this instrument-specific database is called
EDD (Electronic Device Description), in per-
fect analogy to the HART
® environment which
also requires, except with VEGA HART ®
instruments, a DD (Device Description) for
each sensor.