VEGA VEGAPULS 51K…54K Profibus PA - Manual (Page 7)

VEGAPULS 51P … 54P 7
24890-EN-041227
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.
1.4 Adjustment
Each measurement 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, as well as at any system
node (e.g. 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 adjustment, are
available. In the PDM environment, this instru-
ment-specific database is called EDD (Elec-
tronic Device Description), in perfect analogy
to the HART
® environment which also re-
quires, except with VEGA HART ® instru-
ments, a DD (Device Description) for each
sensor.
Product description