Burkert 8681 - 20 POSITION MEASURING SYSTEM

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Position Measuring System
20 POSITION MEASURING SYSTEM
Operating principle of the position measuring system
The position measurement is based on recording the change in position of the ferromagnetic target inside
the system. The geometry and the material of the target to be used are synchronized with the sensitivity of
the system.
The measurement precision is determined by the ferromagnetic properties of the target and all other parts
in the system. While the targets must be ferromagnetic, the other components are ideally made of materials
that do not have ferromagnetic properties – see therefor chapter
“6.7Positionmeasuringsystemdata”on
page 27.
The switching positions of the process valves are reported to the actuator by feedback signals from the
solderless position measuring system. Connection to the control head is done by means of a simple adap-
tationtotheprocessvalve'spiston(valvespindle).
Stroke range / Feedback / Teach functions
The recordable stroke range is between 0 ... 80 mm.
3 discrete feedback are evaluated:
-Position1(discreteS1OUTsignal)
-Position2(discreteS2OUTsignal)
-Position3(discreteS3OUTsignal)
Adiscrete,externalfeedbacksignal(standardproximityswitch/externalinitiator)canalsobeprocessed
(S4IN,S4OUT).
The valve positions S1 to S3 are reported within a certain tolerance range, this feedback range can be
adapted - see chapter “6.8.1Feedbackelds(positionmeasuringsystem)”onpage28.
TheseTeachbuttonsorthePCserviceprogram(forthe24VDC,120VAC,AS-i,DeviceNetvariants)can
beusedtodenetheswitchpositionsofthepositionsensor(Teachprocedure:manualorautomaticTeach
functions).
The control head is connected to the PC via the service interface on the electronic module. For the IO-Link
andbüS/CANopenvariants,theBürkertCommunicator(Type8920)canbeused.ThisrequiresabüSstick
inadditiontotheBürkertCommunicator–seechapter„16AccessoriesforbüSdevices“onpage120.
If an explosive atmosphere is present the housing may not be opened when voltage is present.
For a detailed description of the electrical installation - see
chapter
“1024VDC-Design”onpage40 or
chapter “11120VAC-Design”onpage47 or
chapter “12ASInterface-Design”onpage53 or
chapter “13DeviceNet-Design”onpage62 or
chapter “14IO-Link-Design”onpage75 or
chapter “15büS/CANopen-Design”onpage85 or
chapter “18ConnectionofanExternalInitiator”onpage125 or
chapter “19.2Controlhead(AS-i)with2externalinitiators”onpage128.
english
Control Head Type 8681