epro MMS 6000 - FUNCTION DESCRIPTION; Measuring Amplifier and Signal Conditioning; Signal inputs and sensor supply; Signal conditioning and calculation of characteristical values

 MMS6110Directionforuse 
 Functiondescription  Page31
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4. FUNCTIONDESCRIPTION
ThischaptermainlydescribesthehardwarefunctionsoftheMMS6110ShaftVibrationMoni-
tor.Thefunctionofthemonitordependsontheconfigurationwhichisdescribedinchapter2.
Thefunctionofthehardware(electriccircuits)isshowninblockdiagramfigure1,thecon-
nectiondiagramfig.4showstheconnectiontoexternaldevices.
4.1 MeasuringAmplifierandSignalConditioning
4.1.1 Signalinputsandsensorsupply
TheMMS6110shaftvibrationmonitorhastwodifferentialsignalinputsforeddycurrentsen-
sors,SENS1H(z8)/SENS1L(z10)andSENS2H(d8)/SENS2L(d10).Theyarematchedto
eprosensorsofthePR642.familytogetherwiththerelevantconverters.However,itispos-
sibletoadaptothermeasuringchainwithanidenticalmeasuringprincipleandcorres-
pondingcharacteristics.Theinputvoltagerangeis-1to-22VDC.
TheMMS6110moduleprovidesasensorsupplyoutputforeachchannelwithasupplyvolt-
ageof-26,75Vdc,SENS1+(z6)/SENS1-(b6)andSENS2+(d6)/SENS2-(b8).Thesupply
outputsofbothchannelsaregalvanicallyisolatedfromtheremainingcircuitsofthemonitor
andthesupplyvoltage.
Thesupplyvoltageof-26,75maybeusedforsupplyingtheconvertersCON010,CON020
andCON030althoughtheirsupplyvoltageisindicatedtonominallyto24V.Measuringer-
rorsduetothehighersupplyvoltagewillnotoccur.
Theconnectionofconverterandsensorshouldbecarriedoutaccordingtoconnectiondia-
gramfigure4.TheLow-inputoftheamplifiermustbelinkedtotherelevant+Sensoutputof
thesensorsupply,becauseotherwisethepotential-freeinputcouldcausemeasuringerrors.
Forreasonsofimprovingtheelectromagneticcompatibility(EMC),werecommendlinking
+SensandSensLowattheconverter.
IntheMMS6110monitor,outputSENS-C(b10)isconnectedtogroundandisintendedfor
connectionoftheinternalcableshieldoftwistedpaircablee.g.oftypeLiYCY-CY2x2x0,25
(refertofigure4,connectiondiagram).Theexternalcablescreenofthesensorcables
shouldbelinkedtoexternalground(protectiveearth)ortotheearthconnectionofthecabi-
netothousing.
Thesensorsignalsatthemoduleinputcanbemeasuredatsockets"Sensorsignal"atthe
modulefront.WiththehelpoftheSMB-minicoaxcablesandSMB-BNCadapters,con-
tainedintheMMS6910OperatingKit,oscilloscopesorcorrespondingmeasuringdevices
maybeconnectedtotheMMS6110.Thesocketsareconnectedtothesignalinputsvia1:1
bufferamplifiers.Thustheypermitmeasurementofthestaticsignal(dclevel)whichispro-
portionaltothedistancebetweensensorandmeasuringtargetandtheanalysisofthedy-
namicsignal.
4.1.2 Signalconditioningandcalculationofcharacteristicalvalues
Thesignalconditioningisdeterminedbytheconfiguration.Theconfigurationparametersde-
finetypeanddataofsensorandconverter(sensitivity,linearoperatingrange).More-over,
theyservethedefinitionoftheoperatingmode(dualchannelmode,SmaxaccordingtoDIN
45670ororSppmaxaccordingtoDIN45670BorAPI670.Measuringrange,signalevalua-