Application Example - Vega VEGAMET 381 Ex Instrucción De Servicio

à
To start simulation, push the [ +/-] keys
simultaneously until the displayed value starts
flashing (approx. 3 seconds). By pushing either
of the [ +/-] keys, you can set the requested
simulation value and make your check.
Reset
With a reset, all values set by the user will be lost
and are reset to factory settings.
à
Interrupt the power supply of VEGAMET 381
Ex. Push the [+/-] keys simultaneously and
hold them while you switch on the power
supply. The display shows "RES" and the
default settings will be restored. These are the
following:
Relay switch on points: 10 %
l
Relay switch off points: 100 %
l
Decimal point: 888.8
l
Display min.: 0
l
Display max.: 100.0
l
Integration time: 0 s
l
Offset correction: 0
l
Current output: 4 ... 20 mA
l
Min. adjustment: 0 % or 4 mA
l
Max. adjustment: 100 % or 20 mA
l

6.3 Application example

An upright cylindrical (linear) tank has a volume
l
of 2700 l
The max. filling volume is 2650 l, the min. filling
l
volume 50 l
The level sensor in the vessel is a pressure
l
transmitter (passive), outputting a standardised
4 ... 20 mA signal
For further processing, an additional 4 ... 20 mA
l
output signal is required
The full and empty adjustment was carried out
l
directly in the sensor. The following values are
outputted:
- Max. volume (display max.) 20 mA = 2650 l
-
Min. volume (display min.) 4 mA = 50 l
Relay 1 should switch on an emptying pump at
l
a level of 90 % and switch off the pump at a
level of 10 %
General procedure
1 Select the following functions with the rotary
switch.
VEGAMET 381 Ex
Setup with the integrated indicating and adjustment unit
2 Push one of the two [+/-] adjustment keys, the
digital indication flashes (if the rotary switch is
set to "OPERATE", the [+/-] keys are inoper-
able)
3 Adjust the requested value with the [+/-] keys. If
you hold the key pushed, the digital indication
changes the value more quickly.
4 Save your settings by pushing the [+/-] keys
simultaneously
Current output
à
Set the function switch to position [8]. Select
with the [+/-] keys the measured value output
4 ... 20 mA or 0 ... 20 mA. For this example,
choose 4 - 20.
The displayed numbers have the following mean-
ings:
0 - 20 = 0 ... 20 mA
l
4 - 20 = 4 ... 20 mA
l
à
Save the value by pushing the [+/-] keys
simultaneously
To scale the indication of VEGAMET 381 Ex, the
filling volumes for 0 % and 100 %. The vessel does
not have to be filled or emptied.
Scaled indication at 0 %
1 Set the function switch to position [7] (display
min.)
2 Set the value to 50 via the [+/-] keys
3 Save the value by pushing both keys simulta-
neously
Scaled indication at 100 %
1 Set the function switch to position [6] (display
max.)
2 Set the value to 2650 via the [+/-] keys
3 Save the value by pushing both keys simulta-
neously
Decimal point
Since the range of the example tank is between 50
l and 2650 l, you need a digital indication for every
four positions.
1 Set the function switch to position [5] (Decimal
Point)
2 By pushing the [+/-] keys, you move the
decimal point
3 Save the value by pushing both keys simulta-
neously
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