ApplicationofPLCPLCisonekindspeciallyforthedigitaloperationoperationelectronicinstallationwhichappliesundertheindustryenvironmentdesigns.Itusesmaythecodingmemory,usesforinitsinternalmemoryoperationandsoonactuatinglogicoperation,sequenceoperation,time,countingandarithmeticoperationinstructions,andcanthroughdigitalorthesimulation-likeinputandtheoutput,controlseachtypethemachineryortheproductionprocess.PLCandtherelatedauxiliaryequipmentshouldaccordingtoformawholeeasywiththeindustrialcontrolsystem,easytoexpanditsfunctiontheprincipletodesign.”Inthe1970sthelaststage,theprogrammablecontrollerenteredthepracticalapplicationdevelopmentphase,thecomputertechnologyhasintroducedincomprehensivelytheprogrammablecontroller,causesitsfunctiontohavetheleap.Thehigheroperatingspeed,thesubminiaturevolume,themorereliableindustryantijammingdesign,thesimulationquantityoperation,thePIDfunctionandtheextremelyhighperformance-to-priceratiohasestablisheditinthemodernindustrystatus.Intheearly-1980s,theprogrammablecontrollerhasobtainedthewidespreadapplicationintheadvancedindustrialnation.Thistimeprogrammablecontrollerdevelopsthecharacteristicislarge-scale,thehighvelocity,thehighperformance,theproductseriation.Thisstagesanothercharacteristicisintheworldproducestheprogrammablecontrollerscountrytoincreasedaybyday,theoutputrisesdaybyday.Thissymbolizesthattheprogrammablecontrollermarchedintothematurestage.The20thcenturylaststage,theprogrammablecontrollersdevelopmentcharacteristicwasevenmoreadaptsinthemodernindustryneed.Fromthecontrolscale,thistimehasdevelopedthelarge-scalemachineryandsubminiaturemachine；Fromthecontrol,wasbornvariousspecialfunctionunit,usedinthepressure,thetemperature,therotationalspeed,thedisplacementandsoonallkindsofcontrolsituation；Fromproductnecessaryability,hasproducedeachkindofman-machinecontactsurfaceunit,thecorrespondenceunit,causedtoapplytheprogrammablecontrollersindustrialcontrolequipmentnecessarytobeeasier.Atpresent,theprogrammablecontrollerindomainandsoonmachinemanufacture,petroleumchemicalindustry,metallurgysteelandiron,automobile,lightindustryapplicationsobtainedtheconsiderabledevelopment.Ourcountryprogrammablecontrollersintroduction,applies,thedevelopment,theproductiontofollowthereformandopenpolicytostart.Atfirsthasusedtheprogrammablecontrollermassivelyintheintroductionequipment.ThenexpandedthePLCapplicationunceasinglyineachkindofenterprisesproductionequipmentandtheproduct.Atpresent,ourcountryhavebeenpossibletoproducethemiddleandsmallscaleprogrammablecontroller.EastShanghaitheroomelectricityLimitedcompanyproducestheCFseries,HangzhouenginebedelectricalequipmentfactoryproductionsDKKandDseries,DalianAggregatemachine-toolResearchinstituteproducesSseries,theSuzhouElectronicaccountingmachineFactoryproductionsYZseriesandsoonmanykindsofproductshavehadcertainscaleandhaveobtainedtheapplicationinthemanufacturedproducts.Inaddition,thenon-flowersoftinlightcompany,Chinese-foreignjointventuresandsoonShanghaiTownshipIslandCompanyarealsoourcountryquitefamousPLCManufacturers.Mayanticipatethatalongwithourcountrymodernizationprocesssthorough,PLCwillhavethebroaderapplicationworldinourcountry.UsesthemanualoperationinviewoftheYNLdrawdiemachineelectriccontrolsystem,theexistenceoperationiscomplex,theoperationrequestshigh,needsspeciallyshortcomingsandsoonoperators,hasdesignedPLCthecontrolsystem.Hasgiventheelectricalmachinerymainreturnroute,thePLCperipherywiringdiagram；Hasestablishedthesystemsoperationtrapezoidalchartandtheinstructionlist；Andtothissystemkeyelementshaping.Aftertheimprovementcontrolsystemhasrealizedtheentiresystemboardprocessautomation,notonlyraisedtheproductionefficiency,butalsohassavedthelaborforce,reducedtheproductioncost,mayobtainagreatereconomicefficiency.PLC的應(yīng)用PLC是一種專門為在工業(yè)環(huán)境下應(yīng)用而設(shè)計的數(shù)字運(yùn)算操作的電子裝置。它采用可以編制程序的存儲器，用來在其內(nèi)部存儲執(zhí)行邏輯運(yùn)算、順序運(yùn)算、計時、計數(shù)和算術(shù)運(yùn)算等操作的指令，并能通過數(shù)字式或模擬式的輸入和輸出，控制各種類型的機(jī)械或生產(chǎn)過程。PLC及其有關(guān)的外圍設(shè)備都應(yīng)該按易于與工業(yè)控制系統(tǒng)形成一個整體，易于擴(kuò)展其功能的原則而設(shè)計?！?0世紀(jì)70年代中末期，可編程控制器進(jìn)入實用化發(fā)展階段，計算機(jī)技術(shù)已全面引入可編程控制器中，使其功能發(fā)生了飛躍。更高的運(yùn)算速度、超小型體積、更可靠的工業(yè)抗干擾設(shè)計、模擬量運(yùn)算、PID功能及極高的性價比奠定了它在現(xiàn)代工業(yè)中的地位。20世紀(jì)80年代初，可編程控制器在先進(jìn)工業(yè)國家中已獲得廣泛應(yīng)用。這個時期可編程控制器發(fā)展的特點(diǎn)是大規(guī)模、高速度、高性能、產(chǎn)品系列化。這個階段的另一個特點(diǎn)是世界上生產(chǎn)可編程控制器的國家日益增多，產(chǎn)量日益上升。這標(biāo)志著可編程控制器已步入成熟階段。20世紀(jì)末期，可編程控制器的發(fā)展特點(diǎn)是更加適應(yīng)于現(xiàn)代工業(yè)的需要。從控制規(guī)模上來說，這個時期發(fā)展了大型機(jī)和超小型機(jī)；從控制能力上來說，誕生了各種各樣的特殊功能單元，用于壓力、溫度、轉(zhuǎn)速、位移等各式各樣的控制場合；從產(chǎn)品的配套能力來說，生產(chǎn)了各種人機(jī)界面單元、通信單元，使應(yīng)用可編程控制器的工業(yè)控制設(shè)備的配套更加容易。目前，可編程控制器在機(jī)械制造、石油化工、冶金鋼鐵、汽車、輕工業(yè)等領(lǐng)域的應(yīng)用都得到了長足的發(fā)展。我國可編程控制器的引進(jìn)、應(yīng)用、研制、生產(chǎn)是伴隨著改革開放開始的。最初是在引進(jìn)設(shè)備中大量使用了可編程控制器。接下來在各種企業(yè)的生產(chǎn)設(shè)備及產(chǎn)品中不斷擴(kuò)大了PLC的應(yīng)用。目前，我國自己已可以生產(chǎn)中小型可編程控制器。上海東屋電氣有限公司生產(chǎn)的CF系列、杭州機(jī)床電器廠生產(chǎn)的DKK及D系列、大連組合機(jī)床研究所生產(chǎn)的S系列、蘇州電子計算機(jī)廠生產(chǎn)的YZ系列等多種產(chǎn)品已具備了一定的規(guī)模并在工業(yè)產(chǎn)品中獲得了應(yīng)用。此