外文翻译--变频器和单片机的基本知识.doc

BasicKnowledgeofInvertersandSingle-chipFrequencyACmotorspeedcontrolusedastheprincipalmeanshavebeenusedinawiderangeofapplicationsintheindustrialarea.Ithasawiderangeofspeed,steadyspeedandhighprecision,fastdynamicresponseforawiderangeoftechnicalperformanceandreliableoperationhasbeengraduallyreplacetheDCmotorspeedcontrolsystem.Therearethreemaincontroltypesofinverter:first,throughtheoperatorpanelinverter,thatis,throughtheoperationpaneltochangetheoutputfrequencyandotheroperatingparameters.Second,inthefrequencyconverteranaloginput010Vor420mAsignal.Controltheoutputfrequencybychangingthesizeofinputanalogconverter.Third,controlthecommunicationsportthroughtheinverter.Thefirstsceneingeneralisusedformanualadjustmentandparametersettings,Thelattertwokindsofmethodsaremostlyusedforautomaticregulationandremotecontrol.CommonlyPLC,DCSandothercontrolsystemsinindustrialareaareapplicabletotheconditionsofinverterinterfacecontrolmodule,whichcanfacilitatetherealizationoftheclosed-loopconverterautomaticcontrol.Theyaremorecommonlyusedinlargeandmedium-sizedcontrolsystems.Forsomesmallexperimentaldeviceandembeddedcontroldevice,besidescontrollingthefrequencyconverter,theprocessorgenerallyalsoneedtodealwithkeyboardinput,display,dataacquisitionandotherworksuchasprocesscontrol.Suchcontrolismoresuitableforsingle-chipcontrolsystemasthecore.WhenitcomestothePLCintheformofadditionaloperatingpanel.Itcanachievethefunctionbutthecostistoohigh,Soitshouldnotbeused.Usingsingle-chipcontrolinvertercanchoosethelasttwokindsofmethods.Theadvantageoftheuseofcommunicationcontrolfullcontrolfunction.Bytheappropriatelevel-shiftinginvertercircuitsuitablefortheformofcommunication,thenitcancommunicatewiththeinverter.Thehardwareissimple.Theconnectionbetweenthemfacilitateasmallnumberofconnections.Thedisadvantageistheneedtounderstandthecommunicationprotocolconverterinordertocontroltheprogramming,andthesoftwaredesigniscomplex.Asinverterfordifferentbrandsofcommunicationinterfacesandcommunicationprotocolsaredifferent,thereisnouniformstandardcanonlybedevelopedforafrequencyconverter,whichreducesthechoicevarietiesoffrequencyconverter,andtheapplicabilityislimited.Asfortheanaloginputcontrol,thenalmostalloftheinvertercansupport.Althoughinmoresinglefunction,itcanachievethemainfunctionsofthevariesspeed.Anditcanmeettheuserequirementsofthemajorityofoccasions,soitisuniversal.Themostcommonlyusedmethodofanaloginputspeedisthroughpotentiometertoadjustthefrequency.Thatis,tochangetheanaloginputvoltagevaluetoachievethepurposeofspeedregulation.Althoughtheuseofamechanicalpotentiometerissimple,buteasytowearandhasnoenoughlong-termstability.Besidesthereisoneofthegreatestshortcomingsisthatitisonlysuitableformanualadjustment.Automaticadjustmentcannotbeachieved.DigitalPotentiometersusedtoreplacemechanicalpotentiometersinsingle-chipcontrolnotonlyachievesimpleVVVFmanually,butalsoinaccordancewithPIDclosed-loopcontroltoachieveautomaticcontrol.Itcanberegardedasagoodwayofafull-featuredsingle-chiptocontroltheinverter.Single-chipcomponentsInadditiontooperation,single-chipalsoneedcompletecontrol.Therefore,countingandtimingcannotbeseparated.Asaresult,single-chipissettedwiththecounterandtimersettings.Sofarhere,wealreadyknowthebasiccomponentsofsingle-chip,thatis,single-chipissettedbytheCPU,read-onlymemory,read-writememory,input/outputcomponentsandsoon.Infactthereisalsoasingle-chipclockcircuit,whichduringtheoperationandcontrolofsingle-chipcanbecarriedoutrhythmically.Inaddition,therearetheso-called"interruptsystem"”janitorsroom".Whenthesingle-chipmicrocomputertocontroltheparametersoftheobjectneedtoreachacertainstatetointervene,thenthejanitorsroomcanbecommunicatedtotheCPU.SothatCPUinaccordancewiththeprioritiesofexternalaffairstotakeappropriatecounter-measures.Single-chipinstructionsetandassemblylanguageprogramSingle-chipmicrocomputerhasbeendescribedinfrontofthemaincomponent,thesepartsconstitutesingle-chiphardware.Theso-calledhardware,istosee,canbetouchedandreceived.However,havingsuchahardwareonlymeanshavingthepossibilityoftherealizationofthecalculationandcontrol.Trulysingle-chipmicrocomputertocalculateandcontrolcanalsobeco-ordinationofsoftware.Softwarereferstovariousprocedures.Onlythecorrectprocedurewouldbedepositedinavarietyofsingle-chip,itcanworkeffectively.Therefore,single-chipmicrocomputercanautomaticallycomputingandcontrol,itispreciselybecausepeoplecontroltherealizationofthecalculationstepswithastep-by-steporderform,thatisdepositedinapre-instructionstothememory.IntheCPUscontrol,thesingle-chipwillbeacommandtocheckout,andthetranslationandimplementation.Allofthesetakeanumber,sendafew,thesumofdeposit,etc.areafewoperations.Wehaveimplementedrequiresacomputertooperatewithavarietyofformstowritedowntheorder,whichisinstruction.Buthowcanweidentifythemandtoperformtheseoperations?Thisisasingle-chipinthedesignbythedesignersoftheinstructiongiventoitbydecision.Acommandcorrespondstoabasicoperation.Allthecommandsthatsingle-chipcanimplementisthesingle-chipsystems.differenttypesofsingle-chiphavedifferentcommandsystems.Whenusethesingle-chip,thepriorthatshouldbetheproblemtobesolvedisaseriesofcommands.Theseinstructionsmustbeselectedtoidentifyandimplementsingle-chipinstructions.Single-chipcustomerstosolvetheirownproblemsbytheinstructions,knownasthesource,fortheprocedure.Opcodeinstructionsareusuallydividedintotwomajorparts,whichareoperationofthecomputerandoperand.Operationofthecomputercodemeanstheimplementationofanyoperation,thatis,thefunctionofcommand.Operandmeansparticipateintheoperationoroperandaddressislocated.Becausesingle-chipisaprogrammabledevices,whichrecognizeonlythebinarycode.Inorderoperationsingle-chip,single-chipmicrocomputersysteminalldirectionsmustbeintheformofbinarycodetorepresent.MCS-51single-chiphas8-bitwordlength.Sometimes,itcannotfullycompleteacertainoperationusingonlyoneexpressedbytes.Therefore,thereisnotonlysingle-byteinstruction,butalsoanumberofbyteinstructionsintheinstruction.Byaseriesofbinary0and1components,thereisnoobviouscharacteristics,poormemory,difficulttounderstandandeasytomakemistakes.Therefore,thedirectuseofitisverydifficulttowriteprocedures.Thus,peopleusesomeMnemonicusuallytheEnglishabbreviationofthecommandfunctiontoreplaceopcode.Inthisway,thereareclearinstructionsforeachactionfeatures,easytomemoryandunderstanding,andnotpronetoerror.Mnemonicusedtopreparetheprocessiscalledassemblylanguageprogram.However,Mnemonicpreparedtofacilitateunderstandingoftheprocesscanberecognizedonlysingle-chipbinarymachinecode,so,inordertoallowsingle-chipcan"understand"theassemblylanguageprogrambereplacedbyaprocedureconsistingofbinarymachinecode.Thespeciesoftheconversionprocess,knownascompilation.Compiledcanbeachievedthroughmanuallook-uptablemethod.WealsocandrawonPCmachinethroughtheso-called"cross-assembler"tocomplete.Posedbythebinaryprocess,oncetheuserhasenteredasingle-chip,andthenstartthesingle-chip,itcanentertheprocesstoimplementthemandate.TheCPUof8051single-chipismadeofthecontrollerandthecompositionoperator.CalculatorCalculatorcompletesthebinaryarithmetic/logicoperationsasthecorecomponents.Togetherwithregisters,accumulator,register,theprogrammarksthestateofprocessorregistersandBoolean.Accumulatorisamarkofeightregisters,whichisthemostfrequentlyworkingCPUregister.Inarithmeticandlogicoperations,theaccumulatorisoftentemporaryinapre-computingoperands,andcomputingandthensavetheresults.Registerisprimarilyformultiplicationanddivisionoperations.Registerisalsoamarkofeightregisters,usedtostoresomeresultsofthecharacteristicsofcomputing,suchasbinary,by-bit.ControllerControlleristhenervecenteroftheCPU,whichincludesthetimingcontrollogiccircuit,aninstructionregister,decoder,addresspointerandprogramcounter,stackpointerandsoon.Heretheprogramcounterisofamarkofsixteenregisters.Tomakethesingle-chipoperateimplementationofaprogram,itisnecessarytoadvancetheprogramintoanareaofmemory.Single-chipactionshouldbetakenoutofasequenceofinstructionstobeimplemented.Therefore,theremustbeacircuittofindoutwherethecommandmoduleaddress,andthecircuitistheprogramcounter.Whenthesingle-chipoperateimplementationofprocedures,putintotheprogramcounterwiththeinstructionofthefirsttheaddress.Whenittookoutacommandforeach,theprogramcounterautomaticallyincreasethecontentof1,andpointtothenextinstructionaddress.Sothattheimplementationofdirectivescanbeoperatedinorder.Onlywhenencounteredthetransferofcommandprocedures,subroutinecallinstructions,orfacefailure,theprogramcounterneedgotoplaces.8051CPUsdesignatedaddressfromthememorymoduleoutofthecorrespondinginstructionbytesofstorageontheinstructionregister.Then,theinstructionsininstructionregisterdecodercodehasbeentranslatedintovariousformsofcontrolsignals,thesesignalswiththesingle-chipclockoscillatorgeneratedclockpulseinthetimingandcontrolcircuitincombinationtoformacertainperiodoftimebychangingthebeatlevelandtheclock,whichistheso-calledcontrolofinformation.ItintheInternalcoordinationofCPUdatatransfersbetweenregisters,anddoothercomputingoperations.