Vega VEGAMET 841 Operating page 24

7 Set up with the integrated display and adjustment unit
Scaling
Outputs - Relay outputs
24
further units can be selected. If these have been activated, they are
also shown in the display.
Min. adjustment (empty vessel)
If you want to use the currently measured level as a 0 %value, select
the menu item "Accept" (live adjustment or adjustment with medium).
If the adjustment is to be carried out independently of the measured
level, select the option "Edit". Now enter the appropriate current in
mA for the empty vessel (0 %) (dry adjustment or adjustment without
medium).
Max. adjustment (full vessel)
If you want to use the currently measured level as a 100 %value,
select the menu item "Accept" (live adjustment or adjustment with
medium). If the adjustment is to be carried out independently of the
measured level, select the option "Edit". Now enter the appropriate
current in mA for the full vessel (100 %) (dry adjustment or adjustment
without medium).
Scaling means converting the measured value into a certain param-
eter and unit. The linearized percentage value is the source signal
which is used as basis for the scaling. The indication can then show
the volume in litres e.g., instead of the percentage value. Indication
values from max. -99999 to +99999 are possible.
A total of three relays is available. Relays 1 ... 2 are freely available
and not yet assigned to a function. To be able to use these relays, they
must first be activated. Relay 3 is configured in the factory as a fail
safe relay, but can also be configured as additional operating relay.
After activating a relay output, the desired mode of operation must
first be selected("Overfill protection/Dry run protection").
•
Overfill protection: Relay is switched off when the max. level is
exceeded (safe currentless state), relay is switched on again when
the level falls below the min. level (switch-on point < switch-off
point)
•
Dry run protection: Relay is switched off when the level falls
below the min. level (safe currentless state), relay is switched on
again when the max. level is exceeded (switch-on point > switch-
off point)
Additional modes such as "Pump control", "Switching window",
"Flow" and "Tendency" can be only set via PACTware/DTM or the
VEGA Tools app.
In the menu item "Reference value" it is defined which measured
value serves as input signal for the relay (percentage/lin.-percent/
scaled).
Enter the values for switching the relay on and off under Enter the
values for switching the relay on and off under "Switching point".
The menu item "Behaviour in case of failure" defines how the relay
behaves if the assigned measuring point is disturbed. Here it can be
selected whether the switching state of the relay remains unchanged
or whether the relay is switched off in the event of a failure.
VEGAMET 841 • 4 ... 20 mA