XITRON XT2640 - Page 45

XT2640OperatingManual 13July2016 Page45of187
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12.4.3.1 CONFIGURINGME CHANICALSPEEDMEASUREMENTS
ThemeasurementofmechanicalspeedisconfiguredusingthebuttonsintheSPEEDareashownonthescreen.
TheINPUTbuttonallowsyoutoselectthesourceofmechanicalspeed.
IfyouselectNONEthennomechanicalspeedormechanicalpowerresultswillbeavailablefromtheXT2640.
IfyouselectANALOG(SPD)thenmechanicalspeedwillbecomputedfromthemeasuredDCvoltageontheSPDinputusing
theSCALE(inunitsofrpm/V)andOFFSET(inunitsofrpm)settings.
IfyouselectDIGITAL(SPD)thenmechanicalspeediscomputedfromthemeasuredfrequencyofthedigitalsignalonthe
SPDinputusingtheSCALE(inpulsesperrev)andSPDEDGEsettings.Thedirectionisalwaysconsideredas‘forward’in
thisconfiguration.
IfyouselectDIGITAL(SPD+DIR)thenmechanicalspeediscomputedfromthemeasuredfrequencyofthedigitalsignalon
theSPDinputusingtheSCALE(inpulsesperrev)andSPDEDGEsettingsandthedirectionisdeterminedbythepolarityof
theDIRsignalateachedgeoftheSPDsignalwiththemeaningselectedbytheDIRECTIONbuttonselection.
IfyouselectanelectricalVPA(i.e.VPA1,VPA2orVPA3)thenthemechanicalspeediscomputedfromthemeasured
frequencyofthatVPAusingtheMOTORPOLESsetting.Thedirectionisalwaysconsideredas‘forward’inthis
configuration.
TheSCALEbutton(ifshown)allowsyousetthescalingtoapplytothemeasurementoftheselectedsourceofthespeed
measurement.
TheMOTORPOLESbutton(ifshown)allowsyoutosetthenumberofpolesinthemotor,whichisusedtoscaletheelectrical
frequencyselectedintoanequivalentmechanicalrotationspeed.
TheOFFSETbutton(ifshown)allowsyousettheoffsettoapplytothemeasurementoftheselectedsourceofthespeed
measurement.
TheSPDEDGEbutton(ifshown)allowsyoutoselectwhichedgeofthedigitalSPDsignalisusedforfrequencyanddirection
detectionpurposes(ifenabled).
TheDIRECTIONbutton(ifshown)allowsyoutoselectifaLOlogicleveloraHIlogiclevelontheDIRinputattheselectededgeofthe
SPDsignalistakenasindicatinga‘forward’or‘reverse’direction(i.e.apositiveoranegativespeedrespectively).
TheMOTORSLIPbutton(ifshown)allowsyoutoselectthesourceoftheelectricaldrivefrequency(i.e.whichVPAtoobtainthe
frequencyfrom).YoumayalsoselectNONEtoturnoffthecomputationofmotorslip.IfaVPAisselectedthenyouarealso
promptedtoenterthenumberofmotorpoleswhichisusedtoscalethemechanicalspeedbeforecomparisonwiththeelectrical
drivefrequency.
Note:
Forsimplicity,thedescriptionsaboveassumethatamotorisbeingmeasured.Measurementofageneratorisidentical
withtherespectivesimilarmeaningsforeachbutton.
Althoughusuallyanintegernumber,entryofthenumberofSPDinputpulsesperrevolutionofthemotorisnotrestricted
tointegernumbersbutmustbe≥1.0(i.e.apositive,non‐zeronumber).
Althoughusuallyanintegernumber,entryofthenumberofmotorpolesisnotrestrictedtointegernumbersbutmustbe
>0.0(i.e.apositive,non‐zeronumber)and≤100.
TheSCALEandOFFSETbuttonsallowentriesofanyvaluewitheitherpolarity.
12.4.3.2 CONFIGURINGME CHANICALTORQUEMEASUREMENTS
ThemeasurementofmechanicaltorqueisconfiguredusingthebuttonsintheTORQUEareashownonthescreen.
TheINPUTbuttonallowsyoutoselectthesourceofmechanicaltorque.
IfyouselectNONEthennomechanicaltorqueormechanicalpowerresultswillbeavailablefromtheXT2640.
IfyouselectANALOGthenmechanicaltorquewillbecomputedfromthemeasuredDCvoltageontheTRQinputusingthe
SCALE(inunitsofNm/V)andOFFSET(inunitsofNm)settingsshownbelowtheINPUTbuttononthescreen.
IfyouselectDIGITALthenmechanicaltorqueiscomputedfromthemeasuredfrequencyofthedigitalsignalontheTRQ
inputusingtheSCALE(inNmperHz)andOFFSET(inNm)settingsshownbelowtheINPUTbuttononthescreen.