Development of Real Time Data Acquisition Using PC Printer Port on Virtual Instrument Platform

Abstract

Thisprojectdescribesanapproachtorealtimedataacquisitionandmethodforresultingdataprocessingunderrealtimeconstraintsinvirtualenvionment.DataacquisitionorDAQisaprocessofmeasuringarealworldsignal,andbringingtheinformationfromtheseintoaPCport.Dataacquisitionisatechniquewhichincorporatesfordigitizingananalogsignalobtainedfromasensorwhichsensestherealworldsignals.Thesignalsuchastemperature,pressure,intensityoranyothersignalwhichthesensorconvertsintoelectricalvoltage. TheanalogsignalisconditionedandfeedintoADC(Analogtodigitalconverter)andtheresultingdigitaldataacquisedinPCwiththehelpofsuitabledataacquisitionsoftware.ThereforeacompleteDAQsystemconsistsofsensor,ADC,aPCanddataacquisitionsoftware. The‘C’programminglanguageisusedtodevelopaprogramtoinitiatePCprinterportforsuchdataacquisitionsoftware,flowchart,developedsoftwareandhowtheDLLiscalledfromonetoanotherprogramminglanguageisgiveninthisproject. WehaveconvertedthisdevelopedtextbaseprogramingraphicalprogramminglanguagesuchasLabVIEW.Forimplementingtextbaseprogramingraphicalprogramminglanguage,wehaveusedMicrosoftVC++tobuiltDLLforthissoftwaretoexportthistextbaselanguageingraphicalmode.AfterwritingDLL, theexterncodeexportsinLabVIEWwithhelpofdllexportandcalllibraryfunctionfortheimplementation.Theimplementedfunctionsforrealtimedataacquisitionhavebeenshowninthisproject.