VEGA VEGASON 51P…53P Profibus PA - Manual (Page 6)

6 VEGASON 51P … 53P
Master-Class 1
is the actual automation system, i.e. the proc-
ess control computer or the PLC enquires
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 attached to a VEGA-
SON Profibus sensor. This file is necessary
for integrating the sensor into the bus sys-
tem. The GSD file (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 loaded
from the VEGA homepage: http://
www.vega.com.
Do not mix up the GSD file with the EDD
(Electronic Device Description) necessary for
the PDM environment (this can be also found
on the VEGA homepage).
1.4 Adjustment
Each measuring situation is unique. For that
reason, every ultrasonic sensor needs 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 VEGASON
ultrasonic sensors. The output of echo
curves or the calculation of vessel linearisa-
tion curves by means of vessel dimensions
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, a manufacturer-independ-
ent adjustment program which could be
directly operated on the Profibus DP, but also
from a central point (e.g. the engineering
station or the process control) would be
ideal.
In the past, only the program "SIMATIC
PDM“, based on the HART
® adjustment struc-
ture, could fulfill this wish. However, this pro-
gram also has the same limitation as HART
® .
As with HART ® , an instrument-specific data-
base is required for comprehensive adjust-
ment with PDM (Process Device Managing).
Without this, only basic instrument functions,
such as live adjustment, are available. In the
PDM environment, this instrument-specific
database is called EDD (Electronic Device
Description). Completely analogous to the
HART
® environment, the PDM environment
also requires a DD (Device Description) for
each (with the exception of VEGA HART
®
instruments) sensor.
Product description