基于PC机的软PLC的研究
华中科技大学硕士学位论文
Abstract
1-heworkingprinciplesofsoftProgrammableLogic
structureisControllers(PLC)anditssystemdiscussedinthepaperEspecially,theprocessingofLadderDia野am(LD)andInstructionList(IL),translationalgorithmbetweenthetwolanguagesisdiscussedindetailTheresearchinvolvesofthestudyOnthewholestructureofsoftPLC,themodelconstructionofLDanditsprocessingalgorithm,thecompileinterpreterofILandthetranslationalgorithmbetweenILandLD
TheLDistheprogramminglanguageforthesequencecontrolsystem,composedoftherelays,switches,wiresetc.AftertheLDprogramissimplifiedintotwo—valuelogicalsystem,itcanbelogicallyanalyzedandeffectivelyprocessedbythematrixknowledge
q-heILprogramissimilartotheprogramwfiaeninadvancedprogrmnminglanguageltsprocessresemblesthatofotheradvancedlanguages,whichisrealizedbythecompileprinciples.However.ILprogrmnhasitso、Ⅳncharacters.Therefore.thecompile—interpreter
onofILisimplementedbytheStandardTemplatekibrao'(STL)basedcompileprinciples
TheLDpresentsthefunctionwithsymbolsandshowstherelationshipbetweentheinstructionswithseries—parallelconnections.ThestructureoftheLDisverymuchlikenettopolo毋calgraphicindatestructureTheLDcanbeabstractedasnettopologicalgraphicaccordingtosomerulesThetopologicalsortinnettopologicalgraphicisusedtorealizethetranslationfromtheLDtotheIL
ThetranslationfromtheILtOtheLDactuallymeanstolinkthesymbolsaccordingsomerulesInthepaper,binarytreestructureisusedtoexpressthelogicrelationshipbetweentheinstructions.Thisstructure
LDtorealizetheirtranslationservesasamediumthatlinkstheinstructionand
ThewholesystemisdesignedfollowingsoftwareengineeringdevelopmentthoughtandObject—OrientedModel(OOM)Sothe
SOHI'Cestructureofthesystemisclear,convenientformaintaining.AndthecodeishighlyreusableⅡ