Vega VEGAPULS 68 Operating Instructions Manual page 41

Basic adjustment - Chan-
nel
Basic adjustment - Lin-
earization curve
VEGAPULS 68 • Profibus PA
6 Set up with the display and adjustment module PLICSCOM
Vessel form
Silo
Enter the requested parameters via the appropriate keys, save your
settings and jump to the next menu item with the [->] key.
The channel is the input selector switch for function block (FB) of
the sensor. Within the function block, additional scalings (Out-Scale)
are carried out. In this menu item, the value fir the function block is
selected:
•
SV1 (Secondary Value 1):
– Percent with radar, guided microwave and ultrasonic sensors
– Pressure or height with pressure transmitters
•
SV2 (Secondary Value 2):
– Distance with radar, guided microwave and ultrasonic sensors
– Percent with pressure transmitters
•
PV (Primary Value):
– Linearised percentage value
Channel
PV lin. value
A linearisation is necessary for all vessels in which the vessel volume
does not increase linearly with the level - e.g. in a horizontal cylindri-
cal or spherical tank - and the indication or output of the volume is
required. Corresponding linearisation curves are preprogrammed for
these vessels. They represent the correlation between the level per-
centage and vessel volume. By activating the appropriate curve, the
volume percentage of the vessel is displayed correctly. If the volume
should not be displayed in percent but e.g. in l or kg, a scaling can be
also set in the menu item "Display".
Linearisation curve
Linear
Enter the requested parameters via the appropriate keys, save your
settings and jump to the next menu item with the [->] key.
Caution:
Note the following if the VEGAPULS 68 with corresponding approval
is used as part of an overfill protection system according to WHG
(Water Resources Act):
If a linearisation curve is selected, the measuring signal is no longer
necessarily linear to the filling height. This must be considered by the
user especially when setting the switching point on the limit signal
transmitter.
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