一种实验室自动化和测量的编程环境.docx

一种实验室自动化和测量的编程环境.docx

《一种实验室自动化和测量的编程环境.docx》由会员分享，可在线阅读，更多相关《一种实验室自动化和测量的编程环境.docx（17页珍藏版）》请在冰点文库上搜索。

一种实验室自动化和测量的编程环境

毕业论文说明书

外文文献及翻译

NationalInstrumentsLabVIEW:

AProgrammingEnvironmentforLaboratoryAutomationandMeasurement

Abstract：

NationalInstrumentsLabVIEWisagraphicalprogramminglanguagethathasitsrootsinautomationcontrolanddataacquisition.Itsgraphicalrepresentation,similartoaprocessflowdiagram,wascreatedtoprovideanintuitiveprogrammingenvironmentforscientistsandengineers.Thelanguagehasmaturedoverthelast20yearstobecomeageneralpurposeprogrammingenvironment.LabVIEWhasseveralkeyfeatureswhichmakeitagoodchoiceinanautomationenvironment.Theseincludesimplenetworkcommunication,turnkeyimplementationofcommoncommunicationprotocols（RS232,GPIB,etc.）,powerfultoolsetsforprocesscontrolanddatafitting,fastandeasyuserinterfaceconstruction,andanefficientcodeexecutionenvironment.Wediscussthemeritsofthelanguageandprovideanexampleapplicationsuitewrittenin-housewhichisusedinintegratingandcontrollingautomationplatforms.

Keywords:

NILabVIEW;graphicalprogramming;systemintegration;instrumentcontrol;componentbasedarchitecture;robotics;automation;staticscheduling;dynamicscheduling;database

1Introduction

Cytokineticsisabiopharmaceuticalcompanyfocusedonthediscoveryofsmallmoleculetherapeuticsthattargetthecytoskeleton.Sinceinceptionwehavedevelopedarobusttechnologyinfrastructuretosupportourdrugdiscoveryefforts.Theinfrastructureprovidescapacitytoscreenmillionsofcompoundsperyearintestsrangingfrommultiproteinbiochemicalassaysthatmimicbiologicalfunctiontoautomatedimage-basedcellularassayswithphenotypicreadouts.Therequirementsforprocessingthesenumbersanddiversityofassayshavemandateddeploymentofmultipleintegratedautomationsystems.Forexample,wehaveseveralplatformsforbiochemicalscreening,systemsforlivecellprocessing,automatedmicroscopysystems,andanautomatedcompoundstorageandretrievalsystem.Eachin-houseintegratedsystemisdesignedaroundaroboticarmandcontainsanoptimalsetofplate-processingperipherals（suchaspipettingdevices,platereaders,andcarousels）dependingonitsintendedrangeofuse.Tocreatethemostflexible,highperformance,andcost-effectivesystems,wehavetakentheapproachofbuildingourownsystemsin-house.Thishasgivenustheabilitytointegratethemostappropriatehardwareandsoftwaresolutionsregardlessofwhethertheyarepurchasedfromavendororengineereddenovo,andhencewecanrapidlymodifysystemsasassayrequirementschange.

Tomaximizeplatformconsistencyandmodularity,eachofour10automatedplatformsiscontrolledbyacommon,distributedapplicationsuitethatwedevelopedusingNationalInstruments（NI）LabVIEW.Thisapplicationsuitedescribedindetailbelow,enablesourenduserstocreateandmanagetheirownprocessmodels（assayscripts）inacommonmodelingenvironment,tousetheseprocessmodelsonanyautomationsystemwiththerequireddevices,andallowseasyandrapiddevicereconfiguration.TheplatformissupportedbyacentralOracledatabaseandcanruneitherstaticallyordynamicallyscheduledprocesses.

1.1NILabVIEWBackground

LabVIEW,whichstandsforLaboratoryVirtualInstrumentationEngineeringWorkbenchisagraphicalprogramminglanguagefirstreleasedin1986byNationalInstruments（Austin,TX）.LabVIEWimplementsadataflowparadigminwhichthecodeisnotwritten,butratherdrawnorrepresentedgraphicallysimilartoaflowchartdiagramProgramexecutionfollowsconnectorwireslinkingprocessingnodestogether.Eachfunctionorroutineisstoredasavirtualinstrument（VI）havingthreemaincomponents:

thefrontpanelwhichisessentiallyaformcontaininginputsandcontrolsandcanbedisplayedatruntime,ablockdiagramwherethecodeiseditedandrepresentedgraphically,andaconnectorpanewhichservesasaninterfacetotheVIwhenitisimbeddedasasub-VI.

Figure 1. ExampleNILabVIEWVI.

Thetoppanel（A）showsthefrontpaneloftheVI.Inputdataarepassedthrough“Controls”whichareshowntotheleft.Includedherearenumberinputs,afilepathbox,andageneralerrorpropagationcluster.WhentheVIruns,the“Indicator”outputsontherightofthepanelarepopulatedwithoutputdata.Inthisexample,dataincludenumbers（bothasscalarandarray）,agraph,andtheoutputoftheerrorcluster.Inthebottompanel（B）theblockdiagramfortheVIisshown.Theoutercasestructureexecutesinthe“NoError”case（VIscanmakeinternalerrorsorifcalledasasub-VIthecallermaypropagateanerrorthroughtheconnectorpane）.

Unlikemostprogramminglanguages,LabVIEWcompilescodeasitiscreatedtherebyprovidingimmediatesyntacticandsemanticfeedbackandreducingthetimerequiredfordevelopmentandtesting.2WritingcodeisassimpleasdragginganddroppingfunctionsorVIsfromafunctionspaletteontotheblockdiagramwithinprocessstructures（suchasForLoops,orCaseStructures）andwiringterminals（passinginputvalues,orreferences）.Unittestingissimplifiedbecauseeachfunctionisseparatelyencapsulated;inputvaluescanbesetdirectlyonthefrontpanelwithouthavingtotestthecontainingmoduleorcreateaseparatetestharness.Thefunctionsthatgeneratedatatakecareofmanagingthestorageforthedata.

NILabVIEWsupportsmultithreadedapplicationdesignandexecutescodeinaninherentlyparallelratherthansequentialmanner;assoonasafunctionorsub-VIreceivesallofitsrequiredinputs,itcanbeginexecution.InFigure 1b,allthesub-VIsreceivethearrayinputsimultaneouslyassoonastheForLoopiscomplete,andthustheyexecuteinparallel.Thisisuniquefromatypicaltext-basedenvironmentwherethecontrolflowslinebylinewithinafunction.Whensequentialexecutionisrequired,controlflowcanbeenforcedbyuseofstructuressuchasSequences,Events,orbychainingsub-VIswhereoutputdatafromoneVIispassedtotheinputofthenextVI.

Similartomostprogramminglanguages,LabVIEWsupportsallcommondatatypessuchasintegers,floats,strings,andclusters（structures）andcanreadilyinterfacewithexternallibraries,ActiveXcomponents,and.NETframework.AsshowninFigure 1b,eachdatatypeisgraphicallyrepresentedbywiresofdifferentcolorsandthickness.LabVIEWalsosupportscommonconfigurationmanagementapplicationssuchasVisualSourceSafemakingmultideveloperprojectsreasonabletomanage.ApplicationsmaybecompiledasexecutablesorasDynamicLinkLibraries（DLLs）thatexecuteusingarun-timeenginesimilartotheJavaRuntimeEnvironment.Thedevelopmentenvironmentprovidesavarietyofdebuggingtoolssuchasbreak-points,trace（trace）,andsingle-step.ApplicationscanbedevelopedusingavarietyofdesignpatternssuchasClient-Server,Consumer-Producer,andState-Machine.TherearealsoUML（UnifiedModelingLanguage）modelingtoolsthatallowautomatedgenerationofcodefromUMLdiagramsandstatediagrams.

Overtheyears,LabVIEWhasmaturedintoageneralpurposeprogramminglanguagewithawideruserbase.

2LabVIEWasaPlatformforAutomationandInstrumentation

OurexperiencecreatingbenchtopinstrumentationandintegratedautomationsystemshasvalidatedourchoiceofLabVIEWasanappropriatetool.LabVIEWenablesrapiddevelopmentoffunctionallyrichapplicationsappropriateforbothbenchtopapplicationsandlargerintegratedsystems.Onmanyoccasionswehavefoundthatprojectrequirementsareinitiallyilldefinedorchangeasnewmeasurementsornewassaysaredeveloped..Thereareseveralkeyfeaturesofthelanguagethatmakeitparticularlyusefulinanautomationenvironmentforcreatingapplicationstocontrolandintegrateinstrumentation,manageprocessflow,andenabledataacquisition.

2.1TurnkeyMeasurementandControlFunction

LabVIEWwasoriginallydevelopedforscientistsandengineers.ThelanguageincludesarichsetofprocesscontrolanddataanalysisfunctionsaswellasCOM,.NET,andsharedDLLsupport.Outofthebox,itprovidesturnkeysolutionstoavarietyofcommunicationprotocolsincludingRS232,GPIB,andTCP/IP.ControlstructuressuchastimedWhileLoopsallowsynchronizedandtimeddataacquisitionfromavarietyofhardwareinterfacessuchasPCI,USB,andPXI.

2.2DataSocketandVIServer

Deploymentofanintegratedsystemwithmultiplecontrolcomputersrequirestheautomationcontrolapplicationtocommunicateremotelywithinstrumentdriversexistingonremotecomputers.LabVIEWsupportsadistributedarchitecturebyvirtueofenablingseamlessnetworkcommunicationthroughtechnologiessuchasVIServerandDSTP（datasocketstransferprotocol）.DSTPisanapplicationlayerprotocolsimilartohttpbasedonTransmissionControlProtocol/InternetProtocol（TCP/IP）.Datasocketsalloweasytransferofdatabetweenremotecomputerswithbasicreadandwritefunctions.ThroughVIservertechnology,functioncallscanbemadetoVIsresidingonremotecomputersasthoughtheyareresidingonthelocalcomputer.BothDatasocketsandVIservercanbeconfiguredtocontrolaccessesprivileges.

2.3SimpleUserInterface（UI）Implementation

Inadditiontocommoninterfacecontrolssuchastextboxes,menurings,andcheck-boxes,LabVIEWprovidesarichsetofUIcontrols（switches,LEDs,gauges,arraycontrols,etc.）thatarepertinenttolaboratoryequipment.ThesehavetheiroriginsinLabVIEWslaboratoryrootsandhelpindevelopmentofinterfaceswhichgivescientistsaclearunderstandingofasystem'sstate.LabVIEWsupportsUIconceptsincludingsubpanels（similartotheMultipleDocumentInterface）,splitterbars,andXControls（analogoustoOCXcontrols）.

2.