Emerson MICRO MOTION 2700 - Page 24

Integratethemeterwiththecontrolsystem
CongureFlowSwitchparameters
Display
OFF-LINEMAINT→OFF-LINECONFG→IO→CHB→SETDO→CONFIGFLSW
ProLinkII
ProLink→Conguration→Flow→FlowSwitchSetpoint
ProLink→Conguration→Flow→FlowSwitchVariable
ProLink→Conguration→Flow→FlowSwitchHysteresis
Communicator
5,3,3,FlowSwitchSetpoint
DetailedSetup→CongOutputs→FO/DOCong→FlowSwitchSetpoint
5,3,3,FlowSwitchVariable
DetailedSetup→CongOutputs→FO/DOCong→FlowSwitchVariable
5,3,3,Hysteresis
DetailedSetup→CongOutputs→FO/DOCong→Hysteresis
FlowSwitchisusedtoindicatethattheowrate(measuredbytheconguredowvariable)has
droppedbelowtheconguredsetpoint.Theowswitchisimplementedwithauser-congurable
hysteresis.
Procedure
1.SetDiscreteOutputSourcetoFlowSwitch,ifyouhavenotalreadydoneso.
2.SetFlowSwitchVariabletotheowvariablethatwillbeusedtocontroltheowswitch.
3.SetFlowSwitchSetpointtotheowratebelowwhichyouwanttheowswitchtoturnon.
4.SetHysteresistothepercentageofvariationaboveandbelowthesetpointthatwilloperate
asadeadband.
Hysteresisdenesarangearoundthesetpointwithinwhichtheowswitchwillnotchange.
Thedefaultvalueis5%.Therangeis0.1%to10%.
Forexample,ifFlowSwitchSetpoint=100g/secandHysteresis=5%,andtheowrate
dropsbelow95g/sec,thediscreteoutputwillturnON.ItwillstayONuntiltheowrate
risesabove105g/sec.AtthispointitturnsOFFandwillremainOFFuntiltheowrate
dropsbelow95g/sec.
2.4.2CongureDiscreteOutputPolarity
Display
OFF-LINEMAINT→OFF-LINECONFG→IO→CHB→SETDO→DOPOLAR
ProLinkII
ProLink→Conguration→Frequency/DiscreteOutput→DOPolarity
Communicator
5,3,3,DO1Polarity
DetailedSetup→CongOutputs→FO/DOCong→DO1Polarity
Discreteoutputshavetwostates:ON(active)andOFF(inactive).Twodifferentvoltagelevelsare
usedtorepresentthesestates.DiscreteOutputPolaritycontrolswhichvoltagelevelrepresents
whichstate.
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MicroMotionModel2700TransmitterswithIntrinsicallySafeOutputs