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1、学院毕业设计（论文）文献翻译机械与电气工程学院机械电子工程专业毕业设计(论文)题目基于PLC控制的液体罐装机系统（西门子）学生姓名品牌班级11级机械学号指导教师完成日期201年01月10日评语：指导教师：ThecharacteristicsandtrendsofPLC,DCSandindustrialPCFirst、thecharacteristicsandApplicationofPLC1.PLCApplicationEarlyPLC(ProgrammableLogicController,PLC
2、),mainlytoreplacerelaylogiccontroltoachieve.Withcomputertechnology,communicationstechnologyandtherapiddevelopmentofautomaticcontroltechnology,thePLCwillbethetraditionalrelaycontroltechnologyandtheemergingcomputertechnologyandcommunicationstechnologyint
3、egration,withhighreliability,strongfunctionandflexible,Programmingsimple,easytouseandaseriesofadvantages,aswellasgoodperformanceoftheindustrialenvironmentandcontroltargetsofperformanceinindustrialproductioninawiderangeofapplications.1969,theUnitedState
4、sDigitalEquipmentCorporation(DEC)developedtheworld'sfirstprogrammablecontroller.Earlyseparationfromtheprogrammablecontrollercomponentsandsmallandmedium-sizedintegratedcircuitcomponent,themainfunctionpreviouslyperformedbytherelayiscompletedsequencecontr
5、ol,suchastiming.Theearly1970s,smallsize,strongfunctionandcheapermicroprocessorsusedPLC,makesthePLCfunctionhasbeenenhancedsignificantly.Intermsofhardware,inadditiontomaintainingitsoriginalswitchmodules,hasalsoincreasedthesimulationmodule,remoteI/Omodule
6、sandspecialfunctionmodulesall.Intermsofsoftware,easytousePLCElectricstaffintheladderdiagramprogramminglanguage,inadditiontomaintainingtheoriginallogicfunctions,hasalsoincreasedthearithmeticoperations,dataprocessingandtransmission,communicationsandself-
7、diagnosticcapabilities.Inthe1980's,thelate,asultra-large-scaleintegratedcircuittechnologyisdevelopingrapidly,microprocessormarketasharppricedrop,thePLCmakesthemicroprocessorsusedbythegeneralimprovementingrades.Furthermore,inordertofurtherimprovetheproc
8、essingspeedofPLC,themanufacturerhasdevelopedadedicatedlogicchip,greatlyimprovingthePLChardwareandsoftwarefunctions.2.CharacteristicsPLCInthedevelopedindustrialcountries,PLChasbeenwidelyusedinallindustrialsectors.Accordingto"TheUnitedSta
