Vega VEGAMET 341, Руководство по эксплуатации

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7 Set up with the integrated display and adjustment unit
VEGAMET 341 • 4 … 20 mA
63730-EN-210616
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. -9999999 to +9999999 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.
The current output is used to transfer the measured value to a super-
ordinate system, e.g. a PLC, a process control system or a measured
value indication. This is an active output, i.e. the current is provided
actively. The processing must hence have a passive current input. If
the current output is not used, it can be deactivated in the first menu
item.
The characteristics of the current output can be set to 0 … 20 mA,
4 … 20 mA or inverted. The reaction in case of failure can also be
adapted to the requirements. The reference value you refer to can
also be selected.
Scaling
Outputs - Relay outputs
Outputs - Current output