Operating instructions

41
8 Application examples
VEGAMET 625 • Double channel HART
28970-EN-150129
3
4
5
h1
h3
1
2
Fig. 12: Dierential measurement - weir control
1 Headwater
2 Tail water
3 Dierence h3
4 Reference plane
5 max. level h1
The following steps are necessary:
•
Selection of the application
– Selectunder"Device settings - Application"theentry"Stand-
ard
"andconrmwith[OK]. Via the [->] key you reach the next
step.
•
Addressing of the sensors
– SincebothsensorsareaddressedviaHARTmultidrop,rst
of all the sensor addressing must be carried out (see chapter
"Setup procedure")
– Connect sensor 1 for upstream water
– Enternowunder"Service - Change sensor address"inthe
menuitem"New address"HARTaddress"01"
– Disconnect sensor 1 and connect sensor 2 for downstream
water
– AssignHARTaddress"02"
– Reconnect sensor 1
•
Assignment of the inputs and measurement loops
– Measurementloop1(upstreamwater):Startunder"Meas-
urement loops - Meas. loop 1 - Input - Change input 1 - Sen-
sor selection"themenuitem"Sensor search".Withcorrect
addressing,bothsensorsmustbedisplayed.Selecttherst
sensor with address 01
– Measurementloop2(downstreamwater):Gounder"Meas-
urement loops - Measurement loop 1 - Input - Change input
1 - Sensor selection"tothemenuitem"Sensor list".Selectthe
second sensor with address 02
– Measurementloop3(dierence):This measurement loop
calculatesautomaticallywithoutfurthersettingsthedierence
between upstream water and downstream water (measurement
loop 1 minus measurement loop 2)