PLC控制系统外文翻译

PLC控制系统外文翻译Abstract:Programmablecontrollerinthefieldofindustrialcontrolapplications,andPLCintheapplicationprocess,toensurenormaloperationshouldbenotedthataseriesofquestions,andgivesomereasonablesuggestions.Keywords:PLCIndustrialControlInterferenceWiringGroundProposalDescriptionOver the years, programmable logic controller (hereinafterreferredtoasPLC)fromitsproductiontothepresent,toachieveaconnectiontothestoragelogicalleapoflogic;itsfunctionfromweaktostrong,toachievealogiccontroltodigitalcontrolofprogress;itsapplicationsfromsmalltolarge,simplecontrolstoachieveasingledevicetoqualifiedmotioncontrol,processcontrolanddistributedcontrolacrossthevarioustasks.PLCtodayindealingwithanalog,digitalcomputing,human-machineinterfaceandthenetworkhavebeenasubstantialincreaseinthecapacitytobecomethemainstreamofthefieldofcontrolofindustrialcontrolequipment,inallwalksoflifeplayinganincreasinglyimportantrole.ⅡPLCapplicationareasCurrently,PLChasbeenwidelyusedindomesticandforeignsteel,petroleum, chemical, power, building materials, machinerymanufacturing,automobile,textile,transportation,environmentalandculturalentertainmentandotherindustries,theuseofmainlydividedintothefollowingcategories:BinarylogiccontrolReplacetraditionalrelaycircuit,logiccontrol,sequentialcontrol,canbeusedtocontrolasingledevicecanalso beusedformulti-clustercontrolandautomationlines.Suchasinjectionmoldingmachine,printingmachine,staplermachine,lathe,grindingmachines,packaginglines,platinglinesandsoon.IndustrialProcessControlIntheindustrialproductionprocess,therearesome,suchastemperature, pressure, flow, level and speed, the amount ofcontinuouschange(ie,analog),PLCusingtheappropriateA/DandD/Aconvertermodule,andavarietyofcontrolalgorithmprogramtohandleanalog,completeclosed-loopcontrol.PIDclosedloopcontrolsystemadjustmentisgenerallyusedasaconditioningmethodwasmore.Processcontrolinmetallurgy,chemicalindustry,heattreatment,boilercontrolandsoforthhaveaverywiderangeofapplicationsMotionControlPLCcanbeusedinacircular motionorlinearmotioncontrol.Generallyuseadedicatedmotioncontrolmodule,forexampleasteppermotororservomotordrivensingle-axisormulti-axispositioncontrolmodule,usedinavarietyofmachinery,machinetools,robots,elevatorsandotheroccasions.DataProcessingPLCwithmathematics(includingmatrixoperations,functions,operation,logicoperation),datatransfer,dataconversion,sorting,look-uptable,bitmanipulationfunctions,youcancompletethedatacollection,analysisandprocessing.Dataprocessingisgenerallyused,suchaspapermaking,metallurgy,foodindustry,someofthemajorcontrolsystemCommunicationsandnetworkingPLCcommunicationwiththecommunicationbetweenPLCandthePLCandothercommunicationsbetweenintelligentdevices.Alongwiththedevelopmentoffactoryautomationnetwork,thePLCnowhascommunicationinterface,communicationisveryconvenient.ⅢApplicationfeaturesofPLCHighreliability,stronganti-interferenceHighreliabilityisthekeytoperformanceofelectricalcontrolequipment.PLCastheuseofmodernlargescaleintegratedcircuittechnology,usingthestrictproductionprocess,theinternalcircuitstothe advanced anti-jamming technology, with high reliability.ConstituteacontrolsystemusingPLC,andthesamesizecomparedtorelaycontactorsystem,electricalwiringandswitchcontactshavebeenreducedtohundredsoreventhousandsoftimes,faultalsogreatlyreduced.Inaddition,PLChardwarefailurewithself-detection,failure alarm timely information. In the application software,applicationarealsoincorporatedintotheperipheraldevicefaultdiagnosisprocedure,thesystemisinadditiontoPLCcircuitsanddevicesotherthantheaccessprotectionfaultdiagnosis.Inthisway,thewholesystemextremelyhighreliability.Fullyfurnished,fullyfunctional,applicabilityPLCtotoday,hasformedaseriesproductsofvarioussizes,canbeusedforoccasionsofallsizesofindustrialcontrol.Inadditiontoprocessingotherthanlogic,PLCdata,mostofcomputingpowerhasimproved,canbeusedforavarietyofdigitalcontrolinthefield.Awidevarietyoffunctionalunitsinlargenumbers,sothatpenetrationtothepositionofPLCcontrol,temperaturecontrol,CNCandotherindustrialcontrol.EnhancedcommunicationcapabilitieswithPLCandhuman-machineinterfacetechnology,usingthePLCcontrolsystemcomposedofavarietyofveryeasily.Easy to learn, well engineeringand technical welcomePLCisfacingtheindustrialandminingenterprisesintheindustrialequipment. It interfaces easily, programming language easilyacceptableforengineeringandtechnicalpersonnel.Ladderlanguage,graphicsymbolsandexpressionsandrelaycircuitveryclosetoarenotfamiliarwithelectroniccircuits,computerprinciplesandassemblylanguagedonotunderstandpeoplewhoengageinindustrialcontroltoopenthedoor.Systemdesign,theworkloadissmall,easymaintenance,easytotransformPLClogicwithmemorylogicinsteadofwiring,greatlyreducingthecontrolequipmentexternalwiring,makethecontrolsystemdesignandconstructionofthemuchshorterperiod,whileroutinemaintenanceisalsoeasierup,evenmoreimportantistochangetheproceduresofthesameequipmenthasbeenchangedproductionprocesspossible.Thisisparticularlysuitableformanyvarieties,smallbatchproductionsituations.InstallationandwiringPowerlines,controllinesandpowerlinesandPLCI/Olinesshouldbesplitwiring,isolationtransformerandPLCandI/OshouldbeusedbetweenthecableconnectionShuangjiao.ThePLC'sIOlinesandpowerlinesgoseparatelines,suchastobeinthesamegroove,theseparationofbundledcommunicationlines,DClines,ifconditionsallow,thebestsub-groovealignment,notonlywillithavethegreatestpossibledistanceandcanreducethenoisetoaminimum.PLCshouldstayawayfromstronginterferencesourcessuchaswelding,high-powersiliconrectifierdevicesandlargepowerequipment,notwiththehigh-voltageelectricalswitchinstalledinthesamecabinet.PLCinthecabinetshouldstayawayfrompowerlines(thedistancebetweenthetwoshouldbemorethan200mm).AndPLCcabinetsinstalledwithinthesameinductiveload,suchaslargepowerrelay,contactorcoil,arcshouldbeparallelRCcircuit.PLCinputandoutputseparatelyfromthebestalignment,switchandanalogshouldbelaidseparately.Thetransmissionofanalogsignalsshouldbeshieldedcable,oneendorbothendsoftheshieldshouldbegroundingresistanceshouldbelessthantheshieldinglayer1/10.ACoutputlineandDCoutputlinesdonotusethesamecable,theoutputlineshouldbefar frompowerlinesandpowerlines,toavoidparallel.I/OwiringterminalInputConnectionInputwiringgenerallynottoolong.Butiftheenvironmentinterferewithsmall,smallvoltagedrop,theinputterminalcanbeproperlylonger.●Input/outputlinescannotbeusedwithacable,input/outputlinesshouldbeseparated.Theextentpossiblenormallyopencontactformtoconnecttotheinputintheestablishmentoftheladderandrelaythesameschematiceasytoread。Outputconnection●Outputwiringisdividedintoseparateoutputandpublicoutput.Indifferentgroups,usingdifferenttypesandvoltagelevelsofoutputvoltage.However,outputinthesamegroupcanonlyusethesametype,thesamevoltagelevelofpower.●AsthePLC'soutputdevicesarepackagedinprintedcircuitboardandconnectedtotheterminalboardthatiftheloadshort-circuitconnectingtheoutputcomponents,printedcircuitboardswillbeburned.Withrelayoutput,inductiveloadbornebythesize,willaffecttherelayservicelife,hencetheuseofinductiveloadshallexercisereasonablechoice,oradditionsisolationrelays.●PLCmayinterferewiththeoutputload,sototakemeasurestocontrol,suchastheDCoutputofthecontinuedflowofcontrolprotection,exchangeoftheoutputRCsnubbercircuit,transistorsandresistorsTriacoutputbypasstheprotection.ⅣPLCapplicationsneedtopayattentiontotheproblemsPLCisanautomationcontrolsforindustrialequipment,generallydonotneedtotakemeasures,itcanbedirectlyusedinindustrialenvironments.However,despitethehighreliabilityasmentionedabove,stronganti-interferenceability,butwhentheproductionenvironmentistooharsh,especiallystrongelectromagneticinterference,orinstalledincorrectly,itmaycauseerrororoperatorerror,resultinginincorrectinputandofthewrongoutput,thiswillresultinlossofcontrolandmalfunctionofequipment,whichcannotguaranteethenormaloperationofPLC,PLCcontrolsystemtoimprovethereliabilitydemandsofitsmanufacturersimproveequipmentPLC'santi-jammingcapability;theotherhand,todesign,installationanduseofmaintenanceattachgreatimportancetocoordinatewithtoimproveproblem-solving,andeffectivelyenhancethesystemrobustness.Therefore,inuseshouldbeawareofthefollowingquestions:1Theworkenvironment(1)TemperaturePLCrequiredtemperatureat0~55oC,installation,heatinglargecomponentscannotbeplacedbelowthespacearoundtheventilationandcoolingshouldbelargeenough.(2)HumidityToensurethePLC,insulation,airrelativehumidityshouldbelessthan85%(nocondensation).(3)ShockPLCshouldbemadefromastrongvibrationsource,topreventthevibrationfrequencyis10~55Hzfrequentorcontinuousvibrations.Whentheenvironmentisinevitablewhenusingvibration,shockabsorptiontotakemeasures,suchasglue,suchasusingshockabsorption.AirToavoidcorrosionandflammablegases,suchashydrogenchloride,hydrogensulfide,etc..ThemoretheairofdustorcorrosivegasenvironmentcanbeinstalledinaclosedPLCbettercontrolroomorcontrolcabinet.PowerPLCfortheinterferencecausedbypowerlinehasacertainabilitytoresist.Thereliabilityofpowersupplyindemandingorespeciallyseriousinterferencewiththeenvironment,youcaninstallaisolationtransformer with shielding to reduce interference between theequipmentandland.PLCDC24Voutputgenerallyhasprovidedinput,wheninputwhenusinganexternalDCpowersupply,DCpowersupplyshouldbeused.Becausetheaveragerectifierpowersupply,duetorippleeffects,easytoPLCreceivedanerrormessage.ControlsysteminterferenceanditssourceOn-siteEMIPLCcontrolsystemisthemostcommonandmostlikelyoneofthefactorsaffectingsystemreliability,theso-calledrootoftheproblemsymptomsfirst,identifytheproblemsandtoproposesolutionstotheproblem.Mustbeawareofon-sitesourcesofinterference.ThesourceofinterferenceandgeneralclassificationPLCcontrolsystemaffectthesourceofinterference,mostofcurrentorvoltageproduceddramaticchangesinthelocation,thereasonisthecurrentchangeinmagneticfield,produceselectromagneticradiationonequipment;magneticfieldchangegeneratedcurrents,electromagneticwavesgeneratedhighspeed.Usuallydifferentmodesofelectromagneticinterferencebyinterference,intocommonmodeanddifferentialmodenoiseinterference.Commonmodeinterferenceisthesignal-to-groundpotentialdifference,mainlybythenetworkinseries,topotentialdifferenceandthespaceofelectromagneticradiationinthecommonsignallinesensorstate(inthesamedirection)voltagesuperimposedformed.Common-modevoltagecircuitcanbeconvertedbyasymmetricdifferentialmodevoltage,directimpactonmeasurementandcontrolsignals,resultingincomponentdamage(thisisthenumberofsystemI/Omodule,themainreasonforthehigherfailurerate),thiscandccommon-mode interference also for the exchange. Differential modeinterferenceistheeffectonthesignalinterferencevoltagebetweentwopoles,mainlybytheelectromagneticfieldinthesignalcouplinginducedbytheunbalancedconversioncircuitformedbythecommonmodeinterferencevoltage,thisdisturbancesuperimposedonthesignaldirectlyaffectsthemeasurementandcontrolaccuracy.PLCsystemandthewaythemainsourceofinterferenceStrongelectricalinterferencePLCsystem,thenormalpowersupplybythepowersupply.Asthenetworkscope,itwillbeallthespaceonalineofelectromagneticinterferenceinducedvoltage.Internalchanges,especiallypower,knifeswitchingsurges,large-scalepowerequipmentstartsandstops,causedbyACandDCdrivesharmonics,shortcircuittransientshocksaretransmittedthroughthetransmissionlinepoweroftheoriginaledge.CabinetinterferenceHigh-voltageelectricalcontrolcabinet,alargeinductiveload,confusinglayoutareeasyonthePLCtoacertaindegreeofinterference.TheintroductionofinterferencefromthesignallinePLCcontrolsystemisconnectedwithallkindsofsignaltransmissionlines,inadditiontotheeffectivetransmissionrangeofinformationbuttherewillalwaysbeexternalinterferencesignalintrusion.ThisinterferenceTherearetwomainways:first,sharedbythetransmitterpowersupplyorsignalinstrumentationstringintothegridpowersupplyinterference,whichareoftenneglected;secondsignalinducedbytheinterferenceofelectromagneticradiationofspace,thatisthesignalOnlineexternalsensorinterference,thisisveryserious.IntroducedbythesignalinterferencemaycauseI/Osignalabnormalitiesandaccuracyofworksignificantlyreduced,willcauseseveredamagecomponents.Fromthegroundingsystemdisorder,disturbanceGroundistoimprovetheelectromagneticcompatibilityofelectronicequipment(EMC)isoneeffectivemeans.Properlygrounded,cannotonlyinhibittheimpactofelectromagneticinterference,butalsooutgoinginterferencesuppressionequipment;andthewrongground,itwillintroduceseriousinterferencesignaltoPLCsystemswillnotwork.InterferencewithinthesystemfromthePLCMainlybythesysteminternalcomponentsandcircuitinteractionbetweenelectromagneticradiation,suchaslogiccircuitsandtheirmutualradiationeffectsonanalogcircuits,analogwithlogicandcomponentstotheinteractionbetweentheuseofdonotmatcheachother.InverterInterferenceFirst,startandruntheinverterharmonicsgeneratedintheprocessconductedinterferencegeneratedonthegrid,causingpowergridvoltagedistortion,affectingthequalityofpowersupply;Second,theinverteroutputwillproduceastrongelectromagneticradiationinterference,affectthenormalperipheralwork.Themajoranti-jammingmeasuresthe reasonable processing power and suppress theinterferencepowerintroducedThepowersupplycanbeinstalledintothepowergridinterferenceshieldinglayerwithavariableratioof1:1isolationtransformertoreduceinterferencebetweenequipmentandground,youcanalsopowerinputcascadedLCfiltercircuit.Thecorrectchoiceofaccesssites,improvethegroundingsystemGoodgroundingistoensurereliableoperationoftheimportantconditionsforPLC,toavoidaccidentalvoltageshockhazard.Thepurposeofgroundingusuallyhavetwo,oneforsecurity,theotheristosuppressinterference.CompletePLCcontrolsystemgroundingsystemisanimportantmeasureagainstoneofelectromagneticinterference.PLCcontrolsystem,includinggroundsystems,theshield,theexchangeoflandandprotecttheland.ConfusiononthePLCsystem,groundingsysteminterferenceisprimarilyaplaceofpotentialunevendistributionofaccess,theexistenceofdifferentgroundpointtothepotentialdifferencebetween,causinggroundloopcurrents,affectingthesystemworkproperly.Forexample,cableshieldmustbegroundedpoint,ifthecableshieldatbothendsA,Baregrounded,thereisgroundpotentialdifference,acurrentflowsthroughtheshield,whentheabnormalstate,suchaslightning,thegroundcurrentwillbegreater.Inaddition,shielding,groundingwireandtheearthmightconstituteaclosedloop,inthechangingmagneticfield,theshieldinglayerwillappearinducedcurrentsbyshieldinglayerandthecouplingbetweenthecores,interferencesignalcircuit.Ifthesystemwiththeother ground handling chaos, resulting in circulation may beproducedinplacesrangingpotentialofonlinedistribution,affectingPLCanalogcircuitswithinthelogiccircuitandnormaloperation.PLClogicvoltageinterferewiththeworkofalowertoleranceandlogictothedistributionofpotentialPLCinterferenceeasilyaffectthelogicoperationanddatastorage,dataresultingconfusion,theprogramrunsflyorcrash.Analoggroundpotentialdistributionwillresultindecreasedaccuracy,causingaseriousdistortionofthesignalmonitoringandmalfunction.safetygroundorpowergroundThe power cord ground terminal and the cabinet groundconnectionforsafetygrounding.Suchaspowerleakageorcabinetcharged,canbeimportedfromthesafetyearthground,willnotcauseharm.SystemGroundPLCcontrollertocontrolvariousdeviceswiththesamepotentialandtheground,calledthesystemground.Groundresistanceshallnotbegreaterthan4Ω,normallytakesthePLCequipmentandcontrolsystemstoswitchingpowersupplycabinetwithnegativetermination,asthecontrolsystematically.SignalandshieldgroundingGeneralrequirementsforthesignallinemustbetheonlyreference,theshieldedcableconductedinterferenceencounteredapossibleoccasion,butalsotheonlygroundintheplaceorthecontrolroomtopreventtheformationof"groundloop."Sourcegrounded,thesignalsideoftheshieldshouldbegrounded;nogroundshouldbegroundedinthePLCside;signallinewhenthemiddleconnector,shieldshouldbesecurelyconnectedandbeinsulated,multi-pointgroundmustbeavoided;multipletestpointsignalsandmulti-coretwistedpairshieldedtwistedpairshieldcableconnection,theshieldshouldbemutuallyconnected,andbytheinsulationtreatment,selecttheappropriatesingle-pointgroundingDepartmentcontacts.TheinverterinterferencesuppressionInverterinterferencetreatmentgenerallyfollowingways:Plusisolationtransformer,ismainlydirectedagainstconductedinterferencefromthepowersupplycanbeseparatedmostoftheConductiondisturbancesbeforetheisolationtransformer.Usethefilter,thefilterhasstronganti-interferenceability,alsohastopreventtransmissioninterferencedeviceitselftopower,andsomebothabsorptionpeakvoltage.Usingoutputreactors,anincreaseinthefrequencyconvertertomotorACreactorbetweentheprincipalistoreducetheinverteroutputintheenergytransferprocesslinesproduceelectromagneticradiation,affecttheotherdevicesworkproperly.V.ConclusionPLCcontrolsystem,theinterferenceisav