毕业设计论文 外文文献翻译 中英文对照 plc 发展和市场条件

英文PLCDEVELOPMENTANDMARKETCONDITIONSPLCDEVELOPMENTHISTORYPROGRAMMABLELOGICCONTROLLERSENGLISHNAMEISPROGRAMMABLECONTROLLERINTHE20THCENTURY7080AGECONTINUOUSLYABBREVIATIONISPCASARESULTOFTOTHE90S,THEPERSONALCOMPUTERDEVELOPS,ALSOTHEABBREVIATIONISPCADDSSCOPEWHICHTHEPROGRAMMABLEFOREWORDCONCEPTCOVERSTOOINABIGWAY,THEREFOREAMERICANABCORPORATIONCHOOSESANAMEFORTHEFIRSTTIMETHEPROGRAMMABLEFOREWORDCONTROLLERASTHEPROGRAMMABLEFOREWORDLOGICCONTROLLERPLCPROGRAMMABLELOGICCONTROLLER,INORDERTOBECONVENIENT,STILLWASCALLEDPLCWASTHEPROGRAMMABLEFOREWORDCONTROLLERSOMEPEOPLETHESYSTEMWHICHCOMPOSETHEPROGRAMMABLEFOREWORDCONTROLLERARECALLEDTHEPCSPROGRAMMABLEFOREWORDCONTROLSYSTEM,EMPHASIZEDTHEPROGRAMMABLEFOREWORDCONTROLLERPRODUCTIONMERCHANTPROVIDEDTOTHEPEOPLEALREADYISCOMPLETEISSYSTEMATICIN1968AMERICANGMGENERALAUTOMOBILETHECOMPANYPROPOSEDTHESUBSTITUTIONBLACKWHITECONTROLINSTALLMENTREQUEST,THESECONDYEARAMERICANNUMERALCOMPANYDEVELOPEDTHEFIRSTGENERATIONOFPROGRAMMABLEFOREWORDCONTROLLER,HASSATISFIEDTHEGMCORPORATIONASSEMBLYLINEREQUESTALONGWITHTHEINTEGRATEDCIRCUITTECHNOLOGYANDTHECOMPUTERTECHNOLOGYDEVELOPMENT,NOWHADTHEFIFTHGENERATIONOFPLCPRODUCTINTAKECHANGESTHEGEOMETRYSHAPEANDTHEMACHINECAPABILITYTRANSFORMSASTHECHARACTERISTICMANUFACTUREINDUSTRYANDTAKETHEPHYSICALCHANGEANDTHECHEMICALCHANGETHERAWMATERIALTHEPRODUCTASINTHECHARACTERISTICPROCESSINDUSTRY,BESIDESBYTHECONTINUALQUANTITYPRIMARILYREACTIONCONTROL,HASSPECIALLYHADTHEMASSIVESWITCHESQUANTITYPRIMARILYSPLITRINGSEQUENTIALCONTROLINTHEMANUFACTUREINDUSTRY,ITCARRIESONTHESMOOTHMOVEMENTNUMBERACCORDINGTOTHELOGICALCONDITIONACCORDINGTOTHESUCCESSIONMOVEMENT；MOREOVERALSOHASWITHTHEORDER,THESUCCESSIONHASNOTHINGTODOWITHCARRIESONTHECHAINLIKEPROTECTIONMOVEMENTACCORDINGTOTHELOGICALRELATIONSTHECONTROLASWELLASTHEMASSIVESWITCHESQUANTITY,THEARTERIESIMPULSE,THETIME,THECOUNTER,THESIMULATIONQUANTITYREPORTSTOTHEPOLICEANDSOONTHECONDITIONQUANTITYPRIMARILYDATAACQUISITIONSURVEILLANCEASARESULTOFTHESECONTROLSANDSURVEILLANCEREQUEST,THEREFOREPLCDEVELOPEDTHESUBSTITUTIONRELAYLINEANDCARRIESONTHESEQUENTIALCONTROLPRIMARILYPRODUCTINMANYYEARSPRODUCTIONPRACTICE,HASGRADUALLYFORMEDPLC,DCSANDTHEIPCTRIPODSETSUPTHEPOTENTIAL,LIKETABLE1,BUTALSOHASOTHERSINGLERETURNROUTEINTELLIGENCETYPEREGULATORSANDSOONTOACCOUNTFORTHECERTAINPERCENTAGEINTHEMARKETINTHE80STO90SINTERMEDIATESTAGES,ISPLCDEVELOPSTHEQUICKESTTIME,THEYEARLYRATECONTINUOUSLYMAINTENANCEIS3040ASARESULTOFTHEPLCMACHINERELATIONPROCESSINGSIMULATIONABILITYANDTHENETWORKASPECTFUNCTIONPROGRESS,HASOCCUPIEDAPARTOFDCSMARKETPROCESSCONTROLANDHASGRADUALLYMONOPOLIZEDPROFESSIONANDSOONSEWAGETREATMENT,BUTASARESULTOFINDUSTRYPCIPCTHEAPPEARANCE,SPECIALLYINRECENTYEARSTHEFIELDBUSTECHNOLOGYDEVELOPMENT,IPCANDFCSHAVEALSOOCCUPIEDAPARTOFPLCMARKET,THEREFORETHERECENTYEARSPLCRATEOFRISE,ALWAYSSAYINGWASGRADUALLYSLOWATPRESENTTHEWORLDHASMORETHAN200FACTORIESTOPRODUCEMORETHAN300VARIETIESPLCPRODUCT,MAINAPPLICATIONINAUTOMOBILE23,GRAINPROCESSING164,CHEMISTRY/DRUGSMANUFACTURE146,METAL/MINE115,PAPERPULP/PAPERMAKING113ANDSOONPROFESSIONPLCMARKETCONDITIONSDOMESTICPLCPRODUCTIONFACTORYAPPROXIMATELY30,BUTHASNOTFORMEDQUITEHASTHESCALETHEPRODUCTIVITYANDTHEFAMOUSBRANDGOODS,BUTALSOSOMEPARTISBYIMITATES,THEDOCUMENTRECEIVEDASSEMBLYOR“PASTESTHESIGN“THEWAYPRODUCTION,THEREFOREMAYSAYPLCHASNOTFORMEDTHEMANUFACTUREINDUSTRYINOURCOUNTRYASTHEPRINCIPLE,THETECHNOLOGYANDTHECRAFTDONOTHAVETHEMOSTADVANCEDTECHNIQUEDIFFICULTYTHEPRODUCT,SOLONGASDILIGENTLY,ISCANFORMTHEMANUFACTUREINDUSTRYINTHEPLCAPPLICATIONASPECT,OURCOUNTRYISVERYACTIVE,INRECENTYEARSEVERYYEARAPPROXIMATELYNEWLYINVESTED100,000TOWRAPTHEPLCPRODUCT,THEYEARSALESVOLUME3BILLIONYUAN,ANDTHEAPPLICATIONPROFESSIONVERYISALSOBROADBUTCOMPARESWITHOTHERCOUNTRIES,INMACHINEFINISHINGANDPRODUCTIONLINEASPECTAPPLICATION,BUTALSONEEDSTOENLARGETHEINVESTMENTTHEPLCMARKETPOTENTIALISHUGE,NOTONLYINOURCOUNTRY,EVENIFALSOHASTHEINVESTIGATIONININDUSTRYDEVELOPEDJAPANTOINDICATE,THEPLCNECESSARYINTEGRATIONOFMACHINERYPRODUCTPROPORTIONACCOUNTSFOR42,USEDTHERELAY,THECONTACTDEVICECONTROLSTILLHAS24THEREFORE,NEEDSTOAPPLYPLCTHESITUATIONVERYTOBEALSOMANY,INOURCOUNTRYWASSOLOOKEDFROMTHETECHNICALINNOVATIONANGLETHAT,THEOURCOUNTRYLARGEANDMIDDLESCALEENTERPRISESALSOMUSTVIGOROUSLYDEVELOPCIMSCOMPUTERINTEGRATIONMANUFACTURESYSTEM,MUSTFORMTHEFMSFLEXIBILITYMANUFACTURESYSTEMINTHEMECHANICALFACTORY,PLCISAFOUNDATION,THEREFORETHEPLCMARKETISBROADPLCHASRELIABLE,THEPRICESMALLADVANTAGE,THEFUNCTIONSTABLYCOMPLETE,THEAPPLICATIONNIMBLEISCONVENIENT,THEOPERATIONMAINTENANCECONVENIENTMERIT,THISISITCANLASTINGHOLDTHEMARKETTHEBASICREASON,UNDERUSELABORATEDWITHEMPHASISSEVERALQUESTIONS,ANDSTUDYITSDEVELOPMENTTENDENCY3PLCHARDWAREANDSOFTWARE31PLCCLASSIFICATIONPLCALREADYFORMEDINTHE90SMICRO,SLIGHTLY,CENTER,ISBIG,GIANTMANYKINDSOFPLCDIVIDESACCORDINGTOTHEI/OPOINTS,MAYDIVIDEINTOMINIATUREPLC32I/OSMALLPLC256I/OMEDIUMPLC1,024I/OLARGESCALEPLC4,096I/OGIANTPLC8,195I/OINRECENTYEARSHADTHESINGLEPLANETOSUPPORT300RETURNROUTESANDABOVE65,000I/OLARGESCALESYSTEMCORRESPONDENCEMEDIUMPLC,USED1632POSITIONCPU,MICRO,SMALLPLCORIGINALLYUSED8CPU,NOWACCORDINGTOASPECTANDSOONCOMMUNICATIONREQUESTS,SOMEALSOCHANGEDTO1632POSITIONCPUBECAUSEI/O64BELOWPLCSALESVOLUMEOCCUPIESENTIREPLC47,64256ACCOUNTSFOR31,EQUALSTHEPOSITIONENTIREPLCSALESVOLUME78,THEREFORETOMICRO,SMALLPLCSHOULDSTUDY32PLCHARDWARETHEPLCCONTROLLERITSELFHARDWAREUSESTHEBUILDINGBLOCKSYSTEMSTRUCTURE,VARIOUSFACTORIESPRODUCTSTRUCTUREISMOSTLYTHESAMEEXCEPTFORMINORDIFFERENCESTAKEJAPANESEOHMDRAGONC200HEASANEXAMPLE,FORTHEMAINLINETEMPLATEFRAMETYPESTRUCTURE,THEBAREBONETHECPUFEMALEBOARDONISLOADEDWITHTHECPUTEMPLATE,OTHERPOSITIONSARELOADEDWITHTHEI/OTEMPLATEIFTHEI/OTEMPLATEAREMANYTIME,MAYCONNECTI/OBYTHECPUFEMALEBOARDAFTERTHEI/OEXPANSIONELECTRICCABLETOEXPANDTHEFEMALEBOARD,INSTALLSTHEI/OTEMPLATEINABOVEANOTHERMETHODISPROVIDESLONGDISTANCEI/OFROMTHESTATIONANDSOONTHESEALLEXPLAINEDTHEPLCFACTORYTHEHARDWAREVARIOUSPARTSTOTHEUSERDEVELOPMENT,ISADVANTAGEOUSFORTHEUSERTOSELECT,DISPOSESSCALEDIFFERENTPLC,MOREOVERTHISKINDOFHARDWAREDISPOSESOPENNESS,FORTHEMANUFACTURER,RETAILSBUSINESSBUSINESSAGENT,SYSTEMINTEGRATIONBUSINESS,THEENDUSERBRINGSVERYMANYCONVENIENTCOMESFORTHEMARKETINGSUPPLYTOBEVERYGREATLYCONVENIENT,THISISABIGSUCCESSEXPERIENCEINPLCI/OTEMPLATE,EXCEPTGENERALDI/DO,OUTSIDEAD/DATEMPLATE,BUTALSOHASDEVELOPEDASERIESOFSPECIALFUNCTIONSI/OTEMPLATE,THISWASPLCUSESINALLTHEVARIOUSTRADESANDOCCUPATIONSTOOPENTHEOUTLET,LIKEUSEDINTHEBARCODERECOGNITIONASCII/BASICTEMPLATE,USEDINTHEREACTIONCONTROLPIDTEMPLATE,USEDINTHEOPERATINGCONTROL,THEMACHINEFINISHINGHIGHSPEEDCOUNTINGTEMPLATE,THESINGLEAXLEPOSITIONCONTROLTEMPLATE,THETWOAXLEPOSITIONCONTROLTEMPLATE,THECAMLOCATORTEMPLATE,THERADIOFREQUENCYRECOGNITIONCONNECTIONTEMPLATEANDSOON,THISALSOWILLBEABLETOHAVETHEVERYBIGDEVELOPMENTINLATERMOREOVERINTHEINPUT,THEOUTPUTRELATEDPART,THESITUATIONINPUT,THEOUTPUTELECTRICITYISOLATION,ASPECTANDSOONISOLATIONALSOCANBEMOREPERFECTINPLCCPUANDTHEMEMORYCOORDINATION,COMPLETESTHECONTROLFUNCTIONITWITHDCSSYSTEMPARAMETERANDSOONPROCESSINGTEMPERATURE,PRESSURE,CURRENTCAPACITYSYSTEMDIFFERENT,USESTHEFASTTOURSCANNINGCYCLE,GENERALLYIS0102S,ISQUICKERSELECTS50MSORTHESMALLERSCANNINGCYCLEITISADIGITALSAMPLINGCONTROLSYSTEMCENTRALPROCESSINGUNITCPUISTHEBRAINOFAPLCCONTROLLERCPUITSELFISUSUALLYONEOFTHEMICROCONTROLLERSAFORETIMETHESEWERE8BIT,ANDNOWTHESEARE16AND32BITMICROCONTROLLERSUNSPOKENRULEISTHATYOULLFINDMOSTLYHITACHIANDFUJIMICROCONTROLLERSINPLCCONTROLLERSBYJAPANESEMAKERS,SIEMENSINEUROPEANCONTROLLERS,ANDMOTOROLAMICROCONTROLLERSINAMERICANONESCPUALSOTAKESCAREOFCOMMUNICATION,INTERCONNECTEDNESSAMONGOTHERPARTSOFPLCCONTROLLERS,PROGRAMEXECUTION,MEMORYOPERATION,OVERSEEINGINPUTANDSETTINGUPOFANOUTPUTPLCCONTROLLERSHAVECOMPLEXROUTINESFORMEMORYCHECKUPINORDERTOENSURETHATPLCMEMORYWASNOTDAMAGEDMEMORYCHECKUPISDONEFORSAFETYREASONSGENERALLYSPEAKING,CPUUNITMAKESAGREATNUMBEROFCHECKUPSOFTHEPLCCONTROLLERITSELFSOEVENTUALERRORSWOULDBEDISCOVEREDEARLYYOUCANSIMPLYLOOKATANYPLCCONTROLLERANDSEETHATTHEREARESEVERALINDICATORSINTHEFORMOFLIGHTDIODESFORERRORSIGNALIZATIONSYSTEMMEMORYTODAYMOSTLYIMPLEMENTEDINFLASHTECHNOLOGYISUSEDBYAPLCFORAPROCESSCONTROLSYSTEMASIDEFORMTHISOPERATINGSYSTEMITALSOCONTAINSAUSERPROGRAMTRANSLATEDFORMALADDERDIAGRAMTOABINARYFORMFLASHMEMORYCONTENTSCANBECHANGEDONLYINCASEWHEREUSERPROGRAMISBEINGCHANGEDPLCCONTROLLERSWEREUSEDEARLIERINSTEADOFPLASHMEMORYANDHAVEHADEPROMMEMORYINSTEADOFFLASHMEMORYWHICHHADTOBEERASEDWITHUVLAMPANDPROGRAMMEDONPROGRAMMERSWITHTHEUSEOFFLASHTECHNOLOGYTHISPROCESSWASGREATLYSHORTENEDREPROGRAMMINGAPROGRAMMEMORYISDONETHROUGHASERIALCABLEINAPROGRAMFORAPPLICATIONDEVELOPMENTUSERMEMORYISDIVIDEDINTOBLOCKSHAVINGSPECIALFUNCTIONSSOMEPARTSOFAMEMORYAREUSEDFORSTORINGINPUTANDOUTPUTSTATUSTHEREALSTATUSOFANINPUTISSTOREDEITHERAS“1”ORAS“0”INASPECIFICMEMORYBIT/EACHINPUTOROUTPUTHASONECORRESPONDINGBITINMEMORYOTHERPARTSOFMEMORYAREUSEDTOSTOREVARIABLECONTENTSFORVARIABLESUSEDINUSEDPROGRAMFOREXAMPLE,TIMEVALUE,ORCOUNTERVALUEWOULDBESTOREDINTHISPARTOFTHEMEMORYPLCCONTROLLERCANBEREPROGRAMMEDTHROUGHACOMPUTERUSUALWAY,BUTALSOTHROUGHMANUALPROGRAMMERSCONSOLESTHISPRACTICALLYMEANSTHATEACHPLCCONTROLLERCANPROGRAMMEDTHROUGHACOMPUTERIFYOUHAVETHESOFTWARENEEDEDFORPROGRAMMINGTODAYSTRANSMISSIONCOMPUTERSAREIDEALFORREPROGRAMMINGAPLCCONTROLLERINFACTORYITSELFTHISISOFGREATIMPORTANCETOINDUSTRYONCETHESYSTEMISCORRECTED,ITISALSOIMPORTANTTOREADTHERIGHTPROGRAMINTOAPLCAGAINITISALSOGOODTOCHECKFROMTIMETOTIMEWHETHERPROGRAMINAPLCHASNOTCHANGEDTHISHELPSTOAVOIDHAZARDOUSSITUATIONSINFACTORYROOMSSOMEAUTOMAKERSHAVEESTABLISHEDCOMMUNICATIONNETWORKSWHICHREGULARLYCHECKPROGRAMSINPLCCONTROLLERSTOENSUREEXECUTIONONLYOFGOODPROGRAMSALMOSTEVERYPROGRAMFORPROGRAMMINGAPLCCONTROLLERPOSSESSESVARIOUSUSEFULOPTIONSSUCHASFORCEDSWITCHINGONANDOFFOFTHESYSTEMINPUT/OUTPUTSI/OLINES,PROGRAMFOLLOWUPINREALTIMEASWELLASDOCUMENTINGADIAGRAMTHISDOCUMENTINGISNECESSARYTOUNDERSTANDANDDEFINEFAILURESANDMALFUNCTIONSPROGRAMMERCANADDREMARKS,NAMESOFINPUTOROUTPUTDEVICES,ANDCOMMENTSTHATCANBEUSEFULWHENFINDINGERRORS,ORWITHSYSTEMMAINTENANCEADDINGCOMMENTSANDREMARKSENABLESANYTECHNICIANANDNOTJUSTAPERSONWHODEVELOPEDTHESYSTEMTOUNDERSTANDALADDERDIAGRAMRIGHTAWAYCOMMENTSANDREMARKSCANEVENQUOTEPRECISELYPARTNUMBERSIFREPLACEMENTSWOULDBENEEDEDTHISWOULDSPEEDUPAREPAIROFANYPROBLEMSTHATCOMEUPDUETOBADPARTSTHEOLDWAYWASSUCHTHATAPERSONWHODEVELOPEDASYSTEMHADPROTECTIONONTHEPROGRAM,SONOBODYASIDEFROMTHISPERSONCOULDUNDERSTANDHOWITWASDONECORRECTLYDOCUMENTEDLADDERDIAGRAMALLOWSANYTECHNICIANTOUNDERSTANDTHOROUGHLYHOWSYSTEMFUNCTIONSELECTRICALSUPPLYISUSEDINBRINGINGELECTRICALENERGYTOCENTRALPROCESSINGUNITMOSTPLCCONTROLLERSWORKEITHERAT24VDCOR220VACONSOMEPLCCONTROLLERSYOULLFINDELECTRICALSUPPLYASASEPARATEMODULETHOSEAREUSUALLYBIGGERPLCCONTROLLERS,WHILESMALLANDMEDIUMSERIESALREADYCONTAINTHESUPPLYMODULEUSERHASTODETERMINEHOWMUCHCURRENTTOTAKEFROMI/OMODULETOENSURETHATELECTRICALSUPPLYPROVIDESAPPROPRIATEAMOUNTOFCURRENTDIFFERENTTYPESOFMODULESUSEDIFFERENTAMOUNTSOFELECTRICALCURRENTTHISELECTRICALSUPPLYISUSUALLYNOTUSEDTOSTARTEXTERNALINPUTOROUTPUTUSERHASTOPROVIDESEPARATESUPPLIESINSTARTINGPLCCONTROLLERINPUTSBECAUSETHENYOUCANENSURESOCALLED“PURE”SUPPLYFORTHEPLCCONTROLLERWITHPURESUPPLYWEMEANSUPPLYWHEREINDUSTRIALENVIRONMENTCANNOTAFFECTITDAMAGINGLYSOMEOFTHESMALLERPLCCONTROLLERSSUPPLYTHEIRINPUTSWITHVOLTAGEFROMASMALLSUPPLYSOURCEALREADYINCORPORATEDINTOAPLCPLCAREUSEDINMANY“REALWORLD”APPLICATIONSIFTHEREISINDUSTRYPRESENT,CHANCESAREGOODTHATTHEREISAPLCPRESENTIFYOUAREINVOLVEDINMACHINING,PACKAGING,MATERIALHANDLING,AUTOMATEDASSEMBLYORCOUNTLESSOTHERINDUSTRIES,YOUAREPROBABLYALREADYUSINGTHEMIFYOUARENOT,YOUAREWASTINGMONEYANDTIMEALMOSTANYAPPLICATIONTHATNEEDSSOMETYPEOFELECTRICALCONTROLHASANEEDFORAPLCAPLCWORKSBYCONTINUALLYSCANNINGAPROGRAMWECANTHINKOFTHISSCANCYCLEASCONSISTINGOF3IMPORTANTSTEPS,ASSHOWNINFIG192THEREARETYPICALLYMORETHAN3BUTWECANFOCUSONTHEIMPORTANTPARTSANDNOTWORRYABOUTTHEOTHERSTYPICALLYTHEOTHERSARECHECKINGTHESYSTEMANDUPDATINGTHECURRENTANDTIMERVALUESFIRSTPLCCONTROLLERSWERESIMPLEDEVICESTHEYCONNECTEDINPUTSSUCHASSWITCHES,DIGITALSENSORS,ETC,ANDBASEDONINTERNALLOGICTHEYTURNEDOUTPUTDEVICESONOROFFWHENTHEYFIRSTCAMEUP,THEYWERENOTQUITESUITABLEFORCOMPLICATEDCONTROLSSUCHASTEMPERATURE,POSITION,PRESSURE,ETCHOWEVER,THROUGHOUTYEARS,MAKERSOFPLCCONTROLLERSADDEDNUMEROUSFEATURESANDIMPROVEMENTSTODAYSPLCCONTROLLERCANHANDLEHIGHLYCOMPLEXTASKSSUCHASPOSITIONCONTROL,VARIOUSREGULATIONSANDOTHERCOMPLEXAPPLICATIONSTHESPEEDOFWORKANDEASINESSOFPROGRAMMINGWEREALSOIMPROVEDALSO,MODULESFORSPECIALPURPOSESWEREDEVELOPED,LIKECOMMUNICATIONMODULESFORCONNECTINGSEVERALPLCCONTROLLERSTOTHENETTODAYITISDIFFICULTTOIMAGINEATASKTHATCOULDNOTBEHANDLEDBYAPLCCENTRALPROCESSINGUNITCPUISTHEBRAINOFAPLCCONTROLLERCPUITSELFISUSUALLYONEOFTHEMICROCONTROLLERSAFORETIMETHESEWERE8BITMICROCONTROLLERSSUCHAS8051,ANDNOWTHESEARE16AND32BITMICROCONTROLLERSUNSPOKENRULEISTHATYOULLFINDMOSTLYHITACHIANDFUJISANMICROCONTROLLERSINPLCCONTROLLERSBYJAPANESEMAKERS,SIEMENSINEUROPEANCONTROLLERS,ANDMOTOROLAMICROCONTROLLERSINAMERICANONESCPUALSOTAKESCAREOFCOMMUNICATION,INTERCONNECTEDNESSAMONGOTHERPARTSOFPLCCONTROLLERS,PROGRAMEXECUTION,MEMORYOPERATION,OVERSEEINGINPUTANDSETTINGUPOFANOUTPUTPLCCONTROLLERSHAVECOMPLEXROUTINESFORMEMORYCHECKUPINORDERTOENSURETHATPLCMEMORYWASNOTDAMAGEDMEMORYCHECKUPISDONEFORSAFETYREASONSGENERALLYSPEAKING,CPUUNITMAKESAGREATNUMBEROFCHECKUPSOFTHEPLCCONTROLLERITSELFSOEVENTUALERRORSWOULDBEDISCOVEREDEARLYYOUCANSIMPLYLOOKATANYPLCCONTROLLERANDSEETHATTHEREARESEVERALINDICATORSINTHEFORMOFLIGHTDIODESFORERRORSIGNALIZATIONSYSTEMMEMORYTODAYMOSTLYIMPLEMENTEDINFLASHTECHNOLOGYISUSEDBYAPLCFORAPROCESSCONTROLSYSTEMASIDEFORMTHISOPERATINGSYSTEMITALSOCONTAINSAUSERPROGRAMTRANSLATEDFORMALADDERDIAGRAMTOABINARYFORMFLASHMEMORYCONTENTSCANBECHANGEDONLYINCASEWHEREUSERPROGRAMISBEINGCHANGEDPLCCONTROLLERSWEREUSEDEARLIERINSTEADOFPLASHMEMORYANDHAVEHADEPROMMEMORYINSTEADOFFLASHMEMORYWHICHHADTOBEERASEDWITHUVLAMPANDPROGRAMMEDONPROGRAMMERSWITHTHEUSEOFFLASHTECHNOLOGYTHISPROCESSWASGREATLYSHORTENEDREPROGRAMMINGAPROGRAMMEMORYISDONETHROUGHASERIALCABLEINAPROGRAMFORAPPLICATIONDEVELOPMENTUSERMEMORYISDIVIDEDINTOBLOCKSHAVINGSPECIALFUNCTIONSSOMEPARTSOFAMEMORYAREUSEDFORSTORINGINPUTANDOUTPUTSTATUSTHEREALSTATUSOFANINPUTISSTOREDEITHERAS“1”ORAS“0”INASPECIFICMEMORYBIT/EACHINPUTOROUTPUTHASONECORRESPONDINGBITINMEMORYOTHERPARTSOFMEMORYAREUSEDTOSTOREVARIABLECONTENTSFORVARIABLESUSEDINUSEDPROGRAMFOREXAMPLE,TIMEVALUE,ORCOUNTERVALUEWOULDBESTOREDINTHISPARTOFTHEMEMORYPLCCONTROLLERCANBEREPROGRAMMEDTHROUGHACOMPUTERUSUALWAY,BUTALSOTHROUGHMANUALPROGRAMMERSCONSOLESTHISPRACTICALLYMEANSTHATEACHPLCCONTROLLERCANPROGRAMMEDTHROUGHACOMPUTERIFYOUHAVETHESOFTWARENEEDEDFORPROGRAMMINGTODAYSTRANSMISSIONCOMPUTERSAREIDEALFORREPROGRAMMINGAPLCCONTROLLERINFACTORYITSELFTHISISOFGREATIMPORTANCETOINDUSTRYONCETHESYSTEMISCORRECTED,ITISALSOIMPORTANTTOREADTHERIGHTPROGRAMINTOAPLCAGAINITISALSOGOODTOCHECKFROMTIMETOTIMEWHETHERPROGRAMINAPLCHASNOTCHANGEDTHISHELPSTOAVOIDHAZARDOUSSITUATIONSINFACTORYROOMSSOMEAUTOMAKERSHAVEESTABLISHEDCOMMUNICATIONNETWORKSWHICHREGULARLYCHECKPROGRAMSINPLCCONTROLLERSTOENSUREEXECUTIONONLYOFGOODPROGRAMSALMOSTEVERYPROGRAMFORPROGRAMMINGAPLCCONTROLLERPOSSESSESVARIOUSUSEFULOPTIONSSUCHASFORCEDSWITCHINGONANDOFFOFTHESYSTEMINPUT/OUTPUTSI/OLINES,PROGRAMFOLLOWUPINREALTIMEASWELLASDOCUMENTINGADIAGRAMTHISDOCUMENTINGISNECESSARYTOUNDERSTANDANDDEFINEFAILURESANDMALFUNCTIONSPROGRAMMERCANADDREMARKS,NAMESOFINPUTOROUTPUTDEVICES,ANDCOMMENTSTHATCANBEUSEFULWHENFINDINGERRORS,ORWITHSYSTEMMAINTENANCEADDINGCOMMENTSANDREMARKSENABLESANYTECHNICIANANDNOTJUSTAPERSONWHODEVELOPEDTHESYSTEMTOUNDERSTANDALADDERDIAGRAMRIGHTAWAYCOMMENTSANDREMARKSCANEVENQUOTEPRECISELYPARTNUMBERSIFREPLACEMENTSWOULDBENEEDEDTHISWOULDSPEEDUPAREPAIROFANYPROBLEMSTHATCOMEUPDUETOBADPARTSTHEOLDWAYWASSUCHTHATAPERSONWHODEVELOPEDASYSTEMHADPROTECTIONONTHEPROGRAM,SONOBODYASIDEFROMTHISPERSONCOULDUNDERSTANDHOWITWASDONECORRECTLYDOCUMENTEDLADDERDIAGRAMALLOWSANYTECHNICIANTOUNDERSTANDTHOROUGHLYHOWSYSTEMFUNCTIONSELECTRICALSUPPLYISUSEDINBRINGINGELECTRICALENERGYTOCENTRALPROCESSINGUNITMOSTPLCCONTROLLERSWORKEITHERAT24VDCOR220VACONSOMEPLCCONTROLLERSYOULLFINDELECTRICALSUPPLYASASEPARATEMODULETHOSEAREUSUALLYBIGGERPLCCONTROLLERS,WHILESMALLANDMEDIUMSERIESALREADYCONTAINTHESUPPLYMODULEUSERHASTODETERMINEHOWMUCHCURRENTTOTAKEFROMI/OMODULETOENSURETHATELECTRICALSUPPLYPROVIDESAPPROPRIATEAMOUNTOFCURRENTDIFFERENTTYPESOFMODULESUSEDIFFERENTAMOUNTSOFELECTRICALCURRENTTHISELECTRICALSUPPLYISUSUALLYNOTUSEDTOSTARTEXTERNALINPUTOROUTPUTUSERHASTOPROVIDESEPARATESUPPLIESINSTARTINGPLCCONTROLLERINPUTSBECAUSETHENYOUCANENSURESOCALLED“PURE”SUPPLYFORTHEPLCCONTROLLERWITHPURESUPPLYWEMEANSUPPLYWHEREINDUSTRIALENVIRONMENTCANNOTAFFECTITDAMAGINGLYSOMEOFTHESMALLERPLCCONTROLLERSSUPPLYTHEIRINPUTSWITHVOLTAGEFROMASMALLSUPPLYSOURCEALREADYINCORPORATEDINTOAPLC中文PLC发展和市场条件PLC发展历史可编程逻辑控制器的英文名字是可编程序控制器，在20世纪7080年龄不断的缩写是PC。因此的到了九十年代，个人电脑发展，还缩写是PC添加范围涵盖可编程序概念太在一个大的方法，因此美国AB公司选择一个名称，为第一次的可编程序控制器可编程序逻辑控制器（PLC可编程逻辑控制器），为了方便，仍是要求PLC可编程序控制器有的人，系统所撰写的可编程序控制器称为PC可编程序控制系统，强调已向人民提供的可编程序控制器生产厂商已完成是系统性。在1968年美国GM（通用汽车）公司提出替代黑白控制安装要求，第二年美国数字公司开发出第一代的可编程序控制器，已符合通用汽车公司装配生产线的请求。随着集成电路技术和计算机技术的发展，现在已经第五代的PLC产品。在考虑几何形状的变化和机能力转换特性作为制造行业，并采取物理的变化和化学的变化原料产品作为特色工艺行业中，此外不断的数量由主要反应控制，特别有大规模开关量主要的环状顺序控制在制造工业中，它进行平滑移动号（根据逻辑条件根据演替的运动；此外也有使用顺序，继承并不是与连锁保护运动根据逻辑关系进行控制；以及大规模的交换机数量、动脉的冲动、时间、计数器，模拟量向警察和等等条件数量报告主要数据采集监测。结果这些控件和监视请求，因此PLC开发替代继电器线和顺序控制进行主要产品。在许多年生产实践中，逐步形成了PLC区议会和IPC三脚架的潜力，如表1，设置，但也有其它返回单个路由智力类型监管机构等，以占市场的一定百分比。在80至90年代的中间阶段，是PLC发展最快的时间，每年的速率不断维护是3040。PLC机的结果关系处理模拟能力和网络方面的功能研究进展中，已经占领市场的一部分DCS过程控制和已逐渐垄断行业污水处理，但的工业PCIPC外观，特别是近年来在现场总线技术的发展，IPC和功能界别亦已占领PLC市场的一部分，因此近年来PLC率的上升，总是说是逐步缓慢。目前全球已有超过200家工厂生产的300多个品种PLC产品，主要应用在汽车23、粮食加工164、化学/药品制造146、金属/煤矿115，纸纸浆/造纸113和等行业。国内PLC生产工厂大约30，但不是形成了颇具规模，生产力和著名品牌的商品，但也有些部分是由模仿，收到的文档组件或“贴牌“方式生产，因此可以说PLC不形成了我国的制造行业。作为原则、技术和工艺没有最先进的技术难度产品，那么长时间一样勤，是可以制造行业的窗体。在PLC应用方面，我们的国家很活跃，近年来每年大约新投资的100,000来包装非常的PLC产品、年销售额3亿元人民币和应用专业也很广。但相比之下，在其他国家，在机械加工和生产方面的应用，但也需要扩大投资。PLC的市场潜力是巨大的不仅是在我们的国家，即使在行业调查还制定了以指示，机械产品比例占42，必要的PLC整合日本使用继电器、接触器控制仍有24。因此，需要应用PLC情况很多，在我们国家也是这样。看了从技术创新角度，我国大中型企业还必须大力发展CIMS计算机集成制造系统、形式的FMS灵活性必须制造系统机械工厂，PLC是一个基础，所以PLC市场是广泛。PLC具有可靠、价格小优势，功能稳定完整、灵活的应用程序是方便、操作维修方便的优点，这是它能持久保持市场的基本原因、下我们阐述强调的几个问题，并研究及其发展趋势。3PLC硬件和软件31PLC分类PLC在90年代的微，已经形成轻微，中心，是很大，巨大的许多种类的PLC。分点，依法可分为微型PLC32I/O小型PLC256I/O中小型PLC1,024I/O大型PLC4,096I/O巨人PLC8,195I/O近年来已支持300回程路线的单一平面及以上65,000I/O大型系统函授中小型PLC、使用1632位CPU、微、小型PLC最初使用8CPU，现在可以根据等等方面的通信要求，有些还改为1632位CPU。64256因为I/O64下面PLC销售数量占整个PLC47，占31，位置整个PLC销售数量等于78，因此，微、