lecroy 07_LTXXX-OM-E_Ch3 电路图.pdf

36ISSUED: January2002LTXXX-OM-E Rev B CH A P T E RTH R E E:DisplayYourSignal Inthis chapter, see how Toviewsignalchanges overtime Toset upthe display Toset upforAnalog Persistence Tochoose a grid style Tosave and recallpanelsetups RadioFans.CN 收音机爱 好者资料库 LTXXX-OM-E Rev BISSUED: January200237 CH A P T E RTH R E EDisplayYourSignal DisplayPersistence YoucanuseWaverunner colors andtools todisplayyour signal onthescreen. Viewone, two, four, or eight grids anduptoeight traces (dependingonmodel)at thesametime. Adjust displayand gridintensity. Choosefrom several gridstyles. Or fill the entirescreenwithyour waveforms usingFull Screen. Youcan personalizeyour Waverunner display, while managingcolor andscreenintensityautomatically. The displayedsignal andall relatedinformationshareidentifying colors chosen byyou. Showsignals andtraces opaquelyor transparently, sothat overlappingobjects traces over traces, traces over grids arealways visible. Other invaluabletools andtechniques, suchas the AnalogPersistencefeature, helpyoudisplayyour waveform andreveal its idiosyncrasies. T TI IP P: : Toclearyoursettings and make a “fresh” start ona newwaveform: 1.Connect the signaltobe measured toa Waverunnerchannel. 2.Simultaneouslypress the second and fifthmenu buttons fromthe top, and the CHANNEL SELECT 1button, to revert tothe default settings. 3.Turnoff anyunwanted traces by pressing A, B, C, orD. 4.Press SELECT 1, 2, 3, or4forthe signals channeland choose “Coupling.” Ensure that the coupling matches the circuits impedance. If not, set it correctlyusing the menu button. 5.Press AUTO SETUP twice. Thenfollowthe steps below. VIEW SIGNAL CHANGES OVER TIME UsePersistencetoaccumulateon-screenpoints from manyacquisitions andseeyour signal changeover time. Waverunner persistencemodes showthemost frequent signal path“three-dimensionally” inintensities of the samecolor, or gradedinaspectrum of colors. Todisplayyour waveform withpersistence: 1.Press ANALOG PERSIST todisplayyour signal with AnalogPersistenceor Color Gradedpersistence. 2.Press DISPLAY todisplaythe“DisplaySetup” menus. RadioFans.CN 收音机爱 好者资料库 PA R TON E:G E T T I N GS T A R T E D 38ISSUED: January2002LTXXX-OM-E Rev B SET UP YOUR DISPLAY 3.Usethesemenustoset upyour display.Whennot usingpersistence,somemenus aredifferent,asindicatedbelow . Toselect standardor XY display: Standard is selectedbydefault. SeeChapter 9, “Display More,” for XY display. Toturnpersistenceonor off. Or press ANALOG PERSIST totoggleit on or off. Toset upthepersistencedisplay(seenext page). WhenPersistenceis Off, this menubecomes Dot Join: when therearemorethan400 sample points onthescreen, thepoints areconnectedbylinesegments. Toaccess moredisplaysetupmenus. SeeChapter 9, “Display More.” Toselect thegridstyleandnumber. Seepage40. Usedwithpersistenceto select thedisplayedtracefor the menuactionbelow . When persistenceis not beingused, this menuis calledWform+ Text andits knobadjusts waveform andtext brightness. T TI IP P: : At 0% intensityinStandard display without persistence, the waveformand text disappear. Press DISPLAY toreturnthemtonormal brightness. Usedwithpersistenceto select thepercentageof saturation: 100% spreads thespectrum across theentire depthof thepersistencedatamap; at lower values, the spectrum will saturate brightest color or shade at the percentagevaluespecified. Loweringthis percentagecauses thepixels to besaturatedat alower dataintensity, and makes visiblerarelyhit pixels not seenat higher percentages. When persistenceis not beingused, this menuis called Gridintensity; its knobadjusts theintensityof thegrid. Grids canbebrightened, or blendedwithdisplayedtraces byreducingtheir intensity. Alsopress this menubuttonto returnbrightness from 0% to thedefault level. RadioFans.CN 收音机爱 好者资料库 CH A P T E RTH R E E:DisplayYourSignal LTXXX-OM-E Rev BISSUED: January200239 SET UP FOR PERSISTENCE 4.Press thebuttonfor “PersistenceSetup” toaccess thesemenus. 5.Usethem to set upyour persistencedisplay. Todisplay(On)thelast tracecaptured. Toselect thepersistenceduration, in seconds. If this weretobeset at 1 s, for example, eachcapturedtracewouldbedisplayedfor one secondandthendeleted. Thenumber of sweeps includedinthe display(upto onemillion)is indicatedat thebottom of thedisplayed tracelabel. Thedefault is selectionis Infinite. Toselect persistencefor all, or thetoptwolabeledtraces displayed. This becomes useful whenfour traces or functions areshownand persistencewill not beappliedtoall of them. Toselect Analog, andrender thepersistencedatamaps tothescreen inintensities of thetracecolor, or ColorGraded, wherethemaps are renderedinared-to-violet spectrum. Toselect thedisplayedtracefor themenuactionbelow . Toselect thepercentageof saturation. Seemenu explanation ontheprevious page. RETURN 6.Press togobacktothemaindisplaysetupmenus. T TI IP P: : Press CLEAR SWEEPS torestart the persistence accumulationof points forexample, whenyou change the signalsource and want toclearthe previous trace. PA R TON E:G E T T I N GS T A R T E D 40ISSUED: January2002LTXXX-OM-E Rev B CHOOSE A GRID STYLE At left aretheStandard gridstyles for one, two, andfour grids. Dependingon theWaverunner model, sixor eight traces onsix or eight grids canbeshownat once(see facingpage), withtheir tracelabels andanycombination of math, zoom, andmemories. Standardgrids present sourcewaveforms versus time(for FFT, versus frequency). XY display, ontheother hand, compares onesource waveform withanother. It has its ownspecial grids (see Chapter 9, “Display More”). TheParameter-stylegrid is displayedautomaticallywhen parameters areused(see next chapter). TOLIN K AN DSE PARAT EOBJE CT S WIT HCOL OR Advanced color managementensures that objects grids, waveforms, cursors, or text are always visible, even when overlapping. Signals and their related data are color associated. E ach trace has its own dedicated color. Persistence displays are automatically color matched to the parent trace. Related traces and text, icons and parent-daughter zoom regions are also linked by color. The choice of background coloris limited to the darker colors so that displayed objects will be clearly defined and recognizable. The colors of objects that are too close in hue to the chosen background color are automatically changed so that the objects always stand out. Eachtrace has its owncolor.But expanded or zoomed sections of a trace can be given their own colors, so that a single trace may have a number of colors at once: its principal color plus those of a number of expanded regions. Trace-related textincludes pieces of on-screen information that describe measurement parameters, cursors, triggers, waveforms, and channels. A standard text color covering all on-screen text exists in the preset color schemes, or can be chosen for custom palettes. See Chapter 9, “Display More.” CH A P T E RTH R E E:DisplayYourSignal LTXXX-OM-E Rev BISSUED: January200241 Waveform source descriptions, trace labels and the information they contain will always take the color of their respective traces, as in this four-channel models Octal-grid, eight-trace display. Most menus are displayed inthe text coloronly.The active trigger edge or condition shows source related information in the trace color, as does the trigger icon. Channel Coupling menu titles are trace colored, and Math Set-Up menu sources have their own color. SelectOpaqueto place overlapping waveforms one on top of the other in normal, non-transparent layers. SelectTransparentfor overlap mixing: those areas of the waveforms that overlap will automatically change color, while grid intensity remains constant. See Chapter 9, “Display More.” Objects are automaticallyoverlaid insequence.With traces of the same type, the foremost is described in the top trace label, the next in the second-from-top trace label, and so on in descending order toward the background. Choose the order in which traces appear using the SE L E CT buttons. When different types of traces are displayed, placed by default in ascending order from the grid at the bottom are: envelope traces, persistence traces, normal traces, and cursors (foremost on the screen). This sequence can also be customized. PA R TON E:G E T T I N GS T A R T E D 42ISSUED: January2002LTXXX-OM-E Rev B SaveandRecallYourPanelSetups Your Waverunner scopeallows youtostoreyour preferreddisplaysettings andrecall them later. Or chooseto recall adefault setupalreadyinstalledinthescope. Storingandrecallingpanel setups is verypractical whenyou haveset upelaboratezoom andmathdisplays onmultipletraces andwouldliketousethem onanother signal. Thescopecanstorefour panel setups involatilememory, andmanymoretofloppydiskor theoptional PC Cardslot (memorycardor harddiskcard), innumberedfiles markedwiththeir dateandtimeof storage. You canrecall them quicklyandeasilyfor later use. SAVE PANEL SETUPS 1.Press PANELS for thePANEL SETUPS menus. Usethesemenus tosaveyour preferredpanel setups toSETUP1 in this example. 2.Press toselect Save. 3.Press tosavetoSETUP1. TosavetoSETUP2. TosavetoSETUP3. TosavetoSETUP4. TosavetoPC Cardslot. Tosavetofloppydisk. CH A P T E RTH R E E:DisplayYourSignal LTXXX-OM-E Rev BISSUED: January200243 RECALL PANEL SETUPS 1.Pressto. 2.Presstoselectandrecall thesetupyoustoredfor exampleinSETUP 1. Or, torecall adefault setupalreadystoredinyour scope, press thebuttonto select Or, whenyoustoresetups tofloppydiskor PC Card, press thebuttontoselect Thelast alternativeaccesses theRECALL SETUPS menu, whichenables youtorecall setups from a floppydiskinthefloppydiskdrive, or anoptional portablestoragedevice(PC memorycardor harddisk card)inthePC Cardslot. Tostore and recallthe waveforms themselves, see Chapter5, “Use Math Tools.”