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1、2011-5-8ConnectLabVIEWtoAnyIndustria…DocumentType:TutorialNISupported:YesPublishDate:Jan10,2011ConnectLabVIEWtoAnyIndustrialNetworkandPLCOverviewNationalInstrumentsProgrammableAutomationControllers(PACs)andLabVIEWcanaddawidevarietyoffunctionalitytoexisti
2、ngPLCsandindustrialsystems.Machineconditionmonitoring,high-speedanalogmeasurements,andcustomVisionapplicationsareafewexamplesoftypicalPACapplications.Communicationbetweenthetwosystemsisextremelyimportantandmustbesimple,effective,andoftentimesdeterministi
3、c.ThiswhitepaperwillcoverthedifferentmethodstoconnectLabVIEWandNationalInstrumentsPACstoanyindustrialnetwork,deviceandPLC.TableofContents1.BasicDigitalandAnalogI/O2.ModbusTCPandModbusSerial3.Plug-InCommunicationBoardsBasicDigitalandAnalogI/OPerhapsthesim
4、plestwaytointegrateNationalInstrumentsPACswithexistingPLCsisthroughbasicDigitalorAnalogI/O.AllNationalInstrumentPACplatformshavedigitalI/Oavailable.TheminimumamountofdigitalI/OonaNIPACplatformisontheNICompactVisionsystem.CompactVisionoffers15digitalinput
5、sand14digitaloutputs.WithdigitalI/O,youcancommunicatedatathroughavarietyofmethods.Themostbasicmethodwouldbetotoggleasingledigitalline,allowingyoutosendonebitofdataforthingssuchasstatus,orpass/fail.Ifyouneedtooutputmoreinformation,suchaserrorcodes,orlarge
6、numbers,ortoimplementhandshaking,multipledigitalI/Olinesorportscanbeused.With8digitalI/Olines,youcanreadandwriteupto256distinctvalues.Finally,youcangeneratepulsesacrossadigitalline.Pulsegenerationcanbeusedforprecisiontimingandtriggeringofyourautomationde
7、vices,suchasactuatorsandPLCs.AnalogI/OisalsoagoodoptionforcommunicationbetweenanNIPACandaPLC.WithAnalogI/O,youcansendamuchlargeramountofdatausingasingleline.Witha16-bitDAC,youcouldsendthousandsofdistinctvaluesacrossasingleline.AnalogI/Oisgoodforsendingin
8、crementalchangesforaspecificvalueandusingminimalwires.OneofthedisadvantagesofusingAnalogI/Oforcommunicationisthepossibilityofnoiseandsignalintegrity.IfyourPACorPLCsystemisonthefactoryfloor,theremaybealotofnoisethatcouldcha
