测控技术及仪器 论文翻译英文

本科毕业设计（论文）外文翻译原文学生姓名：王大虎院（系）：电子工程学院专业班级：测控0703班指导教师：贾惠芹完成日期：2011年3月5日1ExpandingtheFeaturesofaVIYoucanchooseoneofmanyLabVIEWVItemplatestouseasastartingpoint.However,sometimesyouneedtobuildaVIforwhichatemplateisnotavailable.ThischapterteachesyouhowtobuildandcustomizeaVIwithoutusingatemplate.BuildingaVIfromaBlankTemplateInthefollowingexercises,youwillopenablankVIandaddExpressVIsandstructurestotheblockdiagramtobuildanewVI.YouwillbuildaVIthatgeneratesasignal,reducesthenumberofsamplesinthesignal,anddisplaystheresultingdatainatableonthefrontpanel.Whenyoucompletetheexercises,thefrontpaneloftheVIwilllooksimilartothefrontpanelinFigure3-1.Youcancompletetheexercisesinapproximately30minutes.Figure3-1.FrontPanelfortheReduceSamplesVIOpeningaBlankVIIfnotemplateisavailableforthetaskyouwanttocreate,youcanstartwithablankVIandaddExpressVIstoaccomplishthespecifictask.CompletethefollowingstepstoopenablankVI.1.IntheLabVIEWdialogbox,clickthearrowontheNewbuttonandselectBlankVIfromtheshortcutmenuorpresstheCtrl-NkeystoopenablankVI.Noticethatablankfrontpanelandblockdiagramappear.2NoteYoualsocanopenablankVIbyselectingBlankVIfromtheCreatenewlistinTheNewdialogboxorbyselectingFile»NewVIfromthefrontpanelorblockdiagrammenubar.2.IftheFunctionspaletteisnotvisible,right-clickanyblankspaceontheblockdiagramtobringupthetemporaryversionoftheFunctionspalette.Clickthethumbtack,shownatleft,intheupperleftcorneroftheFunctionspalettetoplacethepaletteonthescreen.NoteYoucanright-clickonablankspaceontheblockdiagramorthefrontpaneltobringuptheFunctionsorControlspalettes.AddinganExpressVIthatSimulatesaSignalCompletethefollowingstepstofindtheExpressVIyouwanttouseandthenaddittotheblockdiagram.1.IftheContextHelpwindowisnotvisible,presstheCtrl-HkeystoopentheContextHelpwindow.YoualsocanpresstheShowContextHelpWindowbutton,shownatleft,toopentheContextHelpwindow.2.SelecttheInputpaletteontheFunctionspaletteandmovethecursorovertheExpressVIsontheInputpalette.NoticethattheContextHelpwindowdisplaysinformationaboutthefunctionofeachExpressVI.3.FromtheinformationprovidedintheContextHelpwindow,findtheExpressVIthatcanoutputasinewavesignal.4.SelecttheExpressVIandplaceitontheblockdiagram.TheConfigureSimulateSignaldialogboxappears.5.IdlethecursoroverthevariousoptionsintheConfigureSimulateSignaldialogbox,suchasFrequency(Hz),Amplitude,andSamplespersecond(Hz).ReadtheinformationthatappearsintheContextHelpwindow.6.ConfiguretheSimulateSignalExpressVItogenerateasinewavewithafrequencyof10.7andamplitudeof2.7.NoticehowthesignaldisplayedintheResultPreviewwindowchangestoreflecttheconfiguredsinewave.8.ClosetheConfigureSimulateSignaldialogbox.9.MovethecursorovertheSimulateSignalExpressVIandreadtheinformationthat3appearsintheContextHelpwindow.NoticethattheContextHelpwindownowdisplaystheconfigurationoftheSimulateSignalExpressVI.10.SavethisVIasReduceSamples.vitoaneasilyaccessiblelocation.ModifyingtheSignalCompletethefollowingstepstousetheLabVIEWHelptosearchfortheExpressVIthatreducesthenumberofsamplesinasignal.1.SelectHelp»VI,Function,&How-ToHelptoopentheLabVIEWHelp.2.ClicktheSearchtabandtypesamplecompressionintheTypeintheword(s)tosearchfortextbox.NoticethatthiswordchoicereflectswhatyouwantthisExpressVItodo—compress,orreduce,thenumberofsamplesinasignal.3.SelecttheSampleCompressionExpressVItopictodisplaythetopicthatdescribestheSampleCompressionExpressVI.4.AfteryoureadthedescriptionoftheExpressVI,clickthePlaceontheblockdiagrambutton,shownatleft,toselecttheExpressVI.5.Movethecursortotheblockdiagram.NoticehowLabVIEWattachestheSampleCompressionExpressVItothecursor.6.PlacetheSampleCompressionExpressVIontheblockdiagramtotherightoftheSimulateSignalExpressVI.7.ConfiguretheSampleCompressionExpressVItoreducethesignalbyafactorof25usingthemeanofthesevalues.8.ClosetheConfigureSampleCompressiondialogbox.9.UsingtheWiringtool,wiretheSineoutputintheSimulateSignalExpressVItotheSignalsinputintheSampleCompressionExpressVI.CustomizingtheFrontPanelInthepreviousexercises,youaddedcontrolsandindicatorstothefrontpanelusingtheControlspalette.Youalsocanaddcontrolsandindicatorsfromtheblockdiagram.Completethefollowingstepstocreatecontrolsandindicators.41.Right-clicktheMeanoutputintheSampleCompressionExpressVIandselectCreate»NumericIndicatortocreateanumericindicator.2.Right-clicktheMeanoutputoftheSampleCompressionExpressVIandselectInsertInput/OutputfromtheshortcutmenutoinserttheEnableinput.3.Right-clicktheEnableinputandselectCreate»ControltocreatetheEnableswitch.4.Right-clickthewirelinkingtheSineoutputintheSimulateSignalExpressVItotheSignalsinputintheSignalCompressionExpressVIandselectCreate»GraphIndicator.Noticethatyoucancreatecontrolsandindicatorsfromtheblockdiagram.Whenyoureatecontrolsandindicatorsusingthismethod,LabVIEWautomaticallycreatesterminalsthatarelabeledandformattedcorrectly.5.UsingtheWiringtool,wiretheMeanoutputintheSampleCompressionExpressVItotheSineterminal.NoticethattheMergeSignalsfunctionappears.6.ArrangetheobjectsontheblockdiagramsothattheyappearsimilartoFigure3-2.TipYoucanright-clickanywireandselectCleanUp