lecroy 13_LTXXX-OM-E_Ch9 电路图.pdf

112ISSUED: January2002LTXXX-OM-E Rev B CH A P T E RNI N E:DisplayMore Chapter3showed howtoset upthe displayand use persistence. Nowlearnhowtoget more fromyourdisplay. Inthis chapter, see how Analog Persistence works Touse advanced colormanagement tools Tochange yourpalettes and pickcolors Toset upXY display Touse cursors inXY display RadioFans.CN 收音机爱 好者资料库 LTXXX-OM-E Rev BISSUED: January2002113 CH A P T E RNI N EDisplayMore TransformYourVision Press thegreen ANALOG PERSIST buttonandtransform your visionof thewaveform. Withthebrightness levels of a singlecolor, theWaverunner AnalogPersistencefeatureshows relativesignal intensities “threedimensionally” toreveal signal evolution over time. It offers youananalogviewof thewaveform withall theadvantages of a digital oscilloscope. Color Gradedpersistenceworks inasimilar wayusingacolor spectrum tomapsignal intensity. Both Waverunner persistencemodes areinfiniteor variablewithdecayover time. A nalog Persistence display of a signal with elements of a variable frequency of occurrence. RadioFans.CN 收音机爱 好者资料库 PA R TTW O:L O O K I N GD E E P E R 114ISSUED: January2002LTXXX-OM-E Rev B HOWAN AL OGPE RSIST E N CEWORKS L eCroys A nalog Persistence feature offers the advantages of analog display in a DSO (Digital Storage Oscilloscope). The display looks like analog and is fast, too. But it has the data manipulation, flexibility, and statistical analysis capabilities only found in a digital instrument. With traditional analog instruments, data manipulation and the direct comparison of acquisitions is practically impossible. Statistical analysis is difficult to perform too. N evertheless, analog does have certain advantages. Because there is no need for analog-to-digital conversion, the speed of the analog scope is limited only by the bandwidth of its electronics: signals are monitored almost continuously. The standard DSO must capture signals across the time period allowed by the size of its acquisition memory, then process and display their representation. The time needed to process the previous acquisition normally limits DSO speed. But the A nalog Persistence digital oscilloscope is different. It decouples data accumulation from display, accumulating and displaying new data more quickly. Moreover, the persistence is variable. The display is generated by repeated sampling of the amplitudes of events over time, and the accumulation of the sampled data into three-dimensional display maps. These maps create an analog- style display. U ser-definable persistence duration can be used to view how the maps evolve proportionally over time. Statistical integrity is preserved because the duration, or decay, is proportional to the persistence population for each amplitude or time combination in the data. In addition, the A nalog Persistence scope provides user definable, post-acquisition saturation control of the maps, allowing you to draw detail from the display. When you select “A nalog” from the Using persistence menu, each channel and its associated persistence data map are assigned a single color. A s a persistence data map develops, different shades of its color are assigned to the population ranges between a minimum and a maximum population. The maximum population automatically gets the brightest shading, the zero or smallest population gets the darkest shading or the background color, and the population ranges between zero and the maximum population gets the shades in between these. The information in the lower populations, or down at the noise level (random transients rather than dominant signals) could interest you more than the rest. The A nalog Persistence view highlights the distribution of data so that you can more easily examine it in detail. You can select a saturation level or population as a percentage of the maximum population. A ll populations above the saturation population are then assigned the brightest shade: that is, they are saturated. A t the same time, all populations below the saturation level are assigned the remaining shades from brightest down to darkest. Data populations and their displayed shades are dynamically updated as data from new acquisitions is accumulated. RadioFans.CN 收音机爱 好者资料库 CH A P T E RNI N E:DisplayMore LTXXX-OM-E Rev BISSUED: January2002115 TODISPL AYCOL OR-GRADE D PE RSIST E N CE Color-Graded persistence follows the same principles as the A nalog Persistence feature, but uses not one, but many, colors to map signal intensity. When you select “Color Graded” from the Using persistence menu, instead of the brightness of a single color as in the A nalog Persistence view, the Waverunner uses a color spectrum from red through violet to display persistence. The same waveform as that shown on page 113 displayed using Color-Graded persistence shows the persistence waveform in a spectrum of colors rather than shades of a single color. PA R TTW O:L O O K I N GD E E P E R 116ISSUED: January2002LTXXX-OM-E Rev B “Paint” YourDisplay Personalizeyour Waverunner display your “canvas” bychoosingfrom arangeof tools, techniques, and color schemes. 1.IntheDISPLAY SETUP group(seeChapter 3, “Visualize Your Signal”), press thebuttonfor “More DisplaySetup” toaccess thesemenus. 2.Usethem tochangecolor schemes andchooseadvancedcolor management tools. Toactivatethescreensaver. See“First Things.” Toselect either apre-set, default (16)or customized(U1U4)color scheme. Chooseacustom scheme; themenubelowappears. Also selects aschemefor copyingto. Seenext page. Toaccess theCHANGE COLORS menus. Seenext page. ToturnFull ScreenOnandexpandthegriddisplaytofill theentire screen, Offtoreturntothenormal display. Toselect Opaque or Transparent mode, inwhich objects arealways visible. Overlappingregions aredistinguishedbyanewandunique color. ToactivatetheMeasureGatefunction. Objects of lesser interest giventhecolor “neutral” will beautomatically relegatedtotheareaoutsidearegion. Objects insidethis measurement-gateregionarethus highlighted. Toshowdata, or sample, points either as Normalor Bold. RETURN InFull Screen, toremoveall menus from thescreen. Themenus will reappear whenanydarker, labeled, front panel buttonis pressed. CH A P T E RNI N E:DisplayMore LTXXX-OM-E Rev BISSUED: January2002117 CHANGE YOUR PALETTE 3.Press thebuttonfor “ChangeColors” andusethesemenus todothefollowing: Createyour owncolor scheme; assigncolors totraces, grids, or anyother on- screenobject; or copyadefault schemeintoacustom onetomakepersonalizing quicker andeasier. Toselect oneof theapre-set, default (16)or customized(U1U4) color schemes, andcopyit toanother User scheme. This creates a palettethat canthenbemoreeasilypersonalized. TocopytheschemeselectedinthemenuabovetotheUser color schemeselectedintheColor Schememenushownontheprevious page. Toselect thedisplayedobject to beassignedacolor usingthemenu below(seenext page). For selectingthecolor to beassignedtotheobject selectedinthe“Change” menu(seepage119). RETURN ToreturntotheMORE DISPLAY menus. PA R TTW O:L O O K I N GD E E P E R 118ISSUED: January2002LTXXX-OM-E Rev B TOASSIGNCOL ORS TOON-SCRE E NOBJE CT S Background background color of the entire display area Trace 1.4 color assigned to traces displaying Channel 1, 2, or 3 or 4 Trace A.D color assigned to Trace A , B, C, or D Grid default color of the grid Text color assigned to menus, acquisition status and non-single source measurements Cursors color assigned to cursors Warnings color assigned to error and warning messages N eutral color designated as neutral (can be any in user palettes) for measure-gate-region highlighting Overlays color assigned to the menus overlaid on the grid when in Full Screen mode. CH A P T E RNI N E:DisplayMore LTXXX-OM-E Rev BISSUED: January2002119 TOCH OOSECOL ORS Choose from this gallery of colors for your U1, U2, U3, and U4 custom palettes. T TI IP P: : Personalize yourcolor schemes: fortraces, grids, text and menus, cursors, neutral color, background, warnings, and overlays. See the previous page. PA R TTW O:L O O K I N GD E E P E R 120ISSUED: January2002LTXXX-OM-E Rev B SetUpXYDisplay XY displayis for traces that havethesametime- or frequency-span(time/div), expressedusingthesame horizontal unit, inseconds or Hertz. TheXY displayoffers threespecial gridstyles: XY only, XY Singleand XY Dual, illustratedonthenext page. 1.Press DISPLAY for theDISPLAY SETUP menus. 2.Press thebuttontoselect XY from thetopmenu. 3.Usethesemenus toset upyour XY display, andtoaccess other displaysetup menus if desired. Toselect “Standard” or XY. Toturnpersistenceonor off. Or press ANALOG PERSIST Toaccess XY persistencemenus: for choosingAnalogor Color-Graded persistence, andpersistencesaturationinXY display. Toaccess moredisplaysetupmenus. Seepage116. Toselect gridstyleandnumber. Seenext page. Toadjust waveform andtext brightness, usingtheknob. To returntothedefault intensity, press thebutton. Toadjust gridintensityusingtheknob only. Grids canbe brightened, or blendedwithdisplayedtraces. Toreturnto thedefault intensity, press thebutton. CH A P T E RNI N E:DisplayMore LTXXX-OM-E Rev BISSUED: January2002121 A nalog Persistence vector diagram on XY Only grid. Below: XY Only, Single and Dual grids. PA R TTW O:L O O K I N GD E E P E R 122ISSUED: January2002LTXXX-OM-E Rev B TO USECURSORS INXY DISPL AY Cursors are different in XY display (see Chapter 4, “Choose a Measure Tool,” for cursors in general). A bsolute A mplitude cursors are horizontal and vertical bars that can be moved up and down and from side to side across the screen. XY Relative A mplitude cursors are pairs of bars that move in the same way. A bsolute and Relative Time cursors behave in XY as they do in Standard display. Combinations of the amplitude values are shown on the left-hand side of the grid in the following top- to-bottom order: “Y value /X value”:Ratio “20log 10 (ratio)”:Ratio in dB units “Y value X value”:Product “= arc tan (Y /X) range 180to +180”:Angle (polar) “r = sqrt (X X +Y Y)”:Radius (distance to origin). CH A P T E RNI N E:DisplayMore LTXXX-OM-E Rev BISSUED: January2002123 The definition ofX andY depends on which cursor you use. The table below shows howX andY are defined for each type of cursor measurement. XY CURSORS TAbs AAbsARel Org = = = = (0,0) Org = = = = VXOffset VYOffset TRel X VXRef 0VXDif VXRefVXRef 0VXRef VXOffsetVXDif VXRef Y VYRef 0VYDif VYRefVYRef 0VYRef VYOffsetVYDif VYRef Where the terms signify: AAbs: A bsolute A mplitude cursors ARel: Relative A mplitude cursors TAbs: A bsolute Time cursors TRel: Relative Time cursors Org: Origin VXref: V oltage of the Reference cursor on the X trace VYref: V oltage of the Reference cursor on the Y trace VXdif: V oltage of the Difference cursor on the X trace VYdif: V oltage of the Difference cursor on the Y trace