VEGA VEGASON 54P…56P Profibus PA - Manual (Page 7)

VEGASON 54P … 56P 7
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 lineari-
sation curves by means of vessel dimen-
sions are only two examples.
Profibus adjustment scheme
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
operated directly on the Profibus DP, as well
as at any system node (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 scheme,
could fulfil this wish (though with the limita-
tions common to HART
® ). As with HART ® , the
availability of an instrument-specific database
for a comprehensive adjustment with PDM
(Process Device Managing) is a requirement.
Otherwise, only the basic instrument func-
tions, such as adjustment, are available. In
the PDM environment, this instrument-spe-
cific database is called EDD (Electronic De-
vice Description), in perfect analogy to the
HART
® environment which also requires,
except for the VEGA HART ® instruments, a
DD (Device Description) for each sensor.
Product description
We are aware of the disadvantages of the
HART
® environment: for each sensor/partici-
pant, an individual DD must be loaded, which
in addition, must always be the latest and
most up-to-date DD. Special adjustment
options such as e.g., the output of an echo
curve, are available neither with HART
® nor
with PDM. User-friendly adjustment is out of
the question. With VEGA’s adjustment pro-
gram VVO, those restrictions belong to the
past.
The legitimate wish of many Profibus users
for a manufacturer-independent adjustment
tool without EDD has been realised in the
form of PACTware
TM 1) . An association of a
number of process technology companies
developed PACTware
TM : a Process Automa-
tion Configuration Tool that can run different
manufacturer software tools under a stand-
ardised user interface and adjustment
scheme. Specialists call this technology Field
Device Transcription. Just as different Win-
dows printer drivers enable operation of
completely different printers under a single
user interface, PACTware
TM enables operation
of all field instruments under a single user
interface. Instrument-specific databases
(EDD), like those required for SIMATIC PDM,
are not necessary.
As a result of this development, four adjust-
ment media are available for VEGA Profibus
sensors:
- adjustment with the PC and the adjustment
program VVO (VEGA Visual Operating) as
stand-alone tool, on the segment coupler
or directly on the sensor.
- adjustment with the detachable adjustment
module MINICOM in the sensor
- adjustment with the SIMATIC PDM adjust-
ment program (requires EDD instrument
databases) from the control room
- adjustment with the manufacturer-inde-
pendent user interface PACTware TM on the
sensor, from the control room or on the
segment coupler.