Vega ATEX User Manual

32
10 Applications and functions
VEGAMET 841 • 4 … 20 mA
58864-EN-200401
10 Applications and functions
The controller contains already preset applications and functions,
which can be easily adjusted by means of an application assistant via
PACTware/DTM or the VEGA Tools app. The following applications/
functions are described here as examples.
•
Levelmeasurementinstoragetankswithoverllprotection/dryrun
protection
•
Pump station with pump control function
•
Flowmeasurementume/weir
10.1 Level measurement in storage tanks with
overllprotection/dryrunprotection
The level is detected by a sensor and transmitted to the controller
by means of a 4 … 20 mA signal. Here, an adjustment is carried out,
converting the input value delivered by the sensor into a percentage
value.
Depending on the geometrical form of the tank, the vessel volume
does not increase linearly with the level, e.g. with an horizontal cylin-
drical tank. This can be compensated by selecting the linearisation
curve integrated in the instrument. This curve states the relationship
between percentage level and vessel volume. If the level is to be
displayed in litres, a scaling must also be carried out. For this pur-
pose, the linearised percentage value is converted into a volume, for
example with the unit litre.
Filling and emptying are controlled via relay 1 and 2 which are inte-
gratedinthecontroller.Duringlling,relaymode"Overll protection"
isset.Therelayisthusswitchedo(safecurrentlessstate)whenthe
max. level is exceeded, and switched on again when the min. level is
underrun(switch-onpoint<switch-opoint).Duringemptying,mode
"Dry run protection"isused.Thisrelayisthusswitchedowhenthe
min. level is underrun (safe currentless condition), and switched on
againwhenthemax.levelisexceeded(switch-onpoint>switch-o
point).
Application

Vega ATEX Specifications

General

Brand	Vega
Model	ATEX
Category	Controller
Language	English