
PMAC3000Page11
Encoder(optional)
ThePMAC3000isavailablewithanencoderoption.Thisoptioniseasilyverifiedatpowerup
whenthesoftwareversionisdisplayedintheStartupScreen.SeeFigure2.Attheendofthe
softwareversion,“‐E”willappear.
TheencoderversionworkswithquadratureencoderswithsingleendedTTL/CMOSoutputs.It
powerstheencoderwith5VDC.
Therearethreemodesofoperationthatrelatetotheencoder.ThesemodesareOff,Angleand
RPM.HowtoselecttheappropriatemodeisdiscussedintheMenusectionlaterinthismanual.
IntheOffmode,thePMAC3000behavesjustlikeitwouldwiththestandardsoftware(no
encodersoftware).IntheAnglemode,allencodermeasurementsaremadeindegrees.Inthe
RPMmode,allencodermeasurementsaremadeinRPM.InthecaseofAngleandRPMmodes,
thedisplayissplitsuchthatthesensorreadingisontheleftandtheencoderreadingontheright.
Theappropriateunitsareshownbelowthecorrespondingreading.
Theencoderversionprovidesforencoderlimits,justlikethoseprovidedfortheloadsensor.
TheselimitsareLow,Ok,HighandTarget.Ineachcase,theyareevaluatedinthesamewaythat
thesensorlimitsareevaluated.InthevariousPeakmodes,allthelimitsareevaluatedafterthe
processconcludes,whiletheTargetlimitisevaluatedinrealtime.IntheRecordmodes,onlythe
Targetlimitisevaluated.Asbefore,intheRecordmodes,theTargetlimitisevaluatedinreal
time.IntheTrackmode,alllimitsareevaluatedinrealtime.
IntheTrackmode,Anglebeginscountingimmediatelyandmayberesettozerobypressingthe
Tarebutton.NotethatpressingtheTarebuttonalsozero’sthesensorwhenrunninginRelative
mode.RPM,byitsnature,cannotbezeroed.
InthePeakmodes,Anglebeginscountingfromzeroassoonasthesensorloadhascrossedthe
Thresholdvalueandanewcyclehasstarted.Asbefore,ifthesensorloadexceedstheTarget
level,thetargetoutputwillfire.InAnglemode,anyAnglereadingexceedingtheencoderTarget
valuewillalsocausetheTargetoutputtofire.Afterthecyclecompletes,thesensorvalueis
evaluatedwithrespecttothesensorlimits,andtheAnglevalueisevaluatedwithrespecttothe
encoderlimits.InRPMmode,theRPMismonitoredthroughoutthePeakcycle,buttheRPMis
notzeroedatthestartofit.AsinAnglemode,iftheRPMvalueexceedstheencoderTarget
value,theTargetoutputwillfire.Afterthecycleiscomplete,theRPMvalueisevaluatedwith
respecttotheencoderlimits.Ineithercase,AngleorRPMmode,anencoderlimitfailurewill
triggerthecorrespondingoutputandwilllightthecorrespondinglimitindicatoronthefront
panel.ItisthereforepossibletohaveaHighLimitandLowLimitviolationatthesametimeifthe
sensorviolatesoneofitslimitsandtheencoderviolatestheother.Notethat,inthePeakmodes,
theencodervaluethatiscapturedandevaluatedwithrespecttotheHighandLowLimitsisthe
valuethatcoincideswiththepeakvaluefromthesensor.Theencodervaluethatisevaluatedin