the main controls - teledyne lecroy

WP-DDA-UG-E Rev A ISSUED: October 2000 4–1

4 Introduction to the Controls

The Main Controls

4–2 ISSUED: October 2000 WP-DDA-UG-E Rev A

Introduction to the Controls

TRIGGER KNOBS Level. Selects the trigger threshold level. The Level is indicated onthe display grid and at the bottom of the screen.

TRIGGER BUTTONS Setup. Activates the trigger setup menu to select the trigger typeand the trigger conditions. Graphics shown at the bottom of thedisplay indicate the trigger setup.

Stop. Prevents the scope from triggering on a signal.

Auto. Triggers the scope after a selectable time-out, even if thetrigger conditions are not met.

Normal. Triggers the scope each time a signal is present thatmeets the conditions set for the type of trigger selected.

Single. Arms the scope to trigger once (single-shot acquisition)when the input signal meets the trigger conditions set for the type oftrigger selected.

HORIZONTAL KNOBS: Delay. Horizontally positions the scope trace on the display so youcan observe the signal prior to the trigger time. Delay adjusts thepre- and post-trigger time.

Time/Division. Sets the time/division of the scope timebase(acquisition system). LeCroy SMART Memory automaticallyoptimizes the memory and sample rate for maximum resolution.

HORIZONTAL BUTTONS Zero Delay. Sets the horizontal delay to zero. The trigger point ispositioned at the start of the display grid.

Setup. Activates the TIMEBASE menu to allow you to selectacquisition conditions, including the sample mode, maximummemory length, external clocking, etc.

VERTICAL KNOBS Offset. Adjusts the vertical offset of the channel selected bypressing one of the Channels buttons (1, 2, 3, or 4).

Volts/Div. Adjusts the Volts/Division setting (vertical gain) of thechannel selected at the press of one of the "Channel" buttons (1, 2,3, or 4).

CHANNEL BUTTONS 1, 2, 3, 4. These buttons activate the menu that lets you change thechannel’s setup conditions including coupling, gain, and offset. Theyare used also to select multiple grids, to automatically set the gain(FIND), or to automatically display a zoom of the signal. Press twiceto toggle the trace on and off.


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ANALYSIS KNOBS ? Position. Adjusts the horizontal position of a zoom trace on thedisplay. The zoom region is highlighted in color on the source trace.

? Zoom. Adjusts the horizontal zoom (magnification factor) of theselected zoom trace.

?Position. Adjusts the vertical position of the selected zoom traceon the display.

?Zoom. Adjusts the vertical zoom (magnification factor) of theselected zoom trace on the display.

ANALYSIS BUTTONS A, B, C, D. Activates a setup menu for the selected zoom trace soyou can select a source trace for the zoom: either a channel trace oranother zoom trace. Press A, B, C, or D to set up signal processing,including averaging, integration, re-scaling, and other math (signalprocessing) functions. Press a second time to turn the trace off.

Reset. Resets the zoom factors and clears the results from signalprocessing (math operations).

Math Tools. Provides access and an overview of the setup ofzooms and signal processing on all zoom traces.

DRIVE ANALYSIS Channel. Allows you to configure channels.

Servo. Enables analysis of the servo section of the head signal andPosition Error Signal (PES).

Measure. Automatically displays signal parameters, and it is contextsensitive so the parameters on signals, histograms, and FFTs arerelative.

Graph. Allows the use of special drive-specific graphical analysistools, such as sequenced amplitude margin (SAM), Histograms, andPRML “Dot Plots.”

SPECIAL BUTTONS Auto Setup. Automatically sets the scope’s horizontal timebase(acquisition system), vertical gain and offset, as well as triggerconditions, to display a wide variety of signals.

Analog Persist. Provides a three dimensional view of the signal:time, voltage, and a third dimension related to the frequency ofoccurrence, as shown by a color-graded (thermal) or intensity-graded display. It also provides access to the History function, whichmaximizes the update rate and stores the history of up to 8000acquisitions, including trigger time, with 1 ns resolution. Scan



through the history and view, measure, and analyze your signal’scharacteristics.

Cursors. Displays the Wavepilot menu to enable cursors,measurements, and pass/fail testing; and access to AnalysisPackages.

QuickZoom. Automatically displays magnified views of up tofour signal inputs on multiple grids. With four input signals, thesignals are displayed along with four zoom traces, each on its owngrid.

Full Screen. Activates a display mode that maximizes the screenarea used to display the signal for easier viewing of signal details.

CustomDSO. Store your own custom applications in the scope’sNVRAM. Create them offline, and load and access them by meansof the CustomDSO button.

GENERAL BUTTONS Panels. Store scope setting files (Panels) to internal non-volatilevirtual disk (VDISK) or to PC Cards and diskettes. These Panel filescan be recalled to configure the scope to the previously storedsettings.

Utility. For setup of scope features including hardcopy devices andformats, date and time, mass storage devices, and remote controlinterfaces.

Display. For setup of a wide variety of display characteristicsincluding, X-Y mode, persistence, custom trace colors, bold datapoints, etc.

Wave Storage. Store or recall waveform data to optional PC Cardsor to a diskette.

Scope Status. Displays the status of the scope including installedoptions, available memory, serial number, as well as most setupconditions including the acquisition system, and general waveforminformation.

Clear Sweeps. Clears data from multiple sweeps (acquisitions) withthe exception of the last acquisition including: persistence tracedisplays, averaged traces, FFT averaging, etc.

Print Screen. Prints the screen displayed to a diskette or to theoptional: internal printer, PC Card Hard Drive, memory card, ornetwork printer.


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SOFT KEYS & KNOBS Two control knobs linked to display screen. These controlknobs are context sensitive controls whose function depends on thefeature selected. They are used to control measurement cursors,navigate through menus, and select items and conditions displayedin menus.

7 buttons linked to display screen. These buttons are contextsensitive buttons whose function depends on the features selectedand the menu displayed directly to the left of the buttons.

1 button with Return Icon. This button returns the display to theprevious menu, or clears the menu from the screen if the top-levelmenu is being displayed.



Special FeaturesCustomDSO Create Menus and Operations:

CustomDSO files allow you to create custom menus that have user-specific measurement setups or tasks associated with them. UsingCustomDSO, you can

• create custom default setups

• provide semi-automated prompted operations

• create shortcuts to routinely used features

The files can be called from floppy disk, PC card, or non-volatilememory (virtual disk).

1. Press

CUSTOMDSO

in the bottom row of buttons; the default menupanel at left appears.

2. Use these soft keys to quickly execute or toggle somecommonly used features:

TIF2FLPYEnables quick sceen dumps. This assumes that inclusion of therelevant menu panel is not important.

OFFVOLTSToggles the offset units between volts and divisions.

CURTHINToggles the appearance of cursors between thin and thick.

CUR_DBMToggles the cursor units between dBm and volts.

LOGO_OFFTurns the LeCroy logo displayed at the top of the grid on or off.

DEFAULTSSelects system default settings.

Map File to KeyAllows you to assign .dso files to the six menu soft keys above. (Seenext page.)


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Select ; the menu at left appears. Use thismenu panel to assign files to soft keys 1 through 6 of theCustomDSO menu panel, counting from the top.

KeySelects the soft key to associate with a file.

On DriveSelects the storage device that contains the file to be executedwhen you press key 2 of the "CustomDSO" menu panel. The PCcard is optional. See next page for an explanation of Vdisk.

Map Math andAssigns a math setup (see next page), and five parameters, to thekey selected in the box above. This box only appears if Vdisk isselected in the "On Drive" menu.

Key x runsSelects the file to associate with the selected menu key. The filedisplayed here reflects the cursor placement in the scroll list below.

FileScrolls to the desired file of the selected storage device. A promptline will be displayed here if the selected media or storage device isnot installed.

Use the associated knob to rapidly scroll to the desired file.

SET CUSTOM TO DEFAULTAssigns six frequently used functions to the menu soft keys.



Storage Devices:

Whenever a file on the floppy drive or (optional PC card or harddisk) is selected for assignment to a menu key, the file is alsowritten to v irtual disk (Vdisk).

Virtual disk uses a portion of the WavePro DSO’s non-volatileRAM for storage. You can assign any file in v irtual memory to akey, such as a screen dump function, or you can map a mathsetup.

The math mapping function pertains to the scope’s response toa group of nine queries:

TA:DEFINE?TB:DEFINE?TC:DEFINE?TD:DEFINE?PACU? 1PACU? 2PACU? 3PACU? 4PACU? 5

The response to these queries might look something like this:

A:DEFEQN,"HIST(CUST1)",MAXBINS,200,MAX_EVENTS,2000,CENTER,7.48389,WIDTH,1,VERT,LINTB:DEFEQN,"PS(FFT(TA))",MAXPTS,1000,WINDOW,RECT,DCSUP,ONTC:DEFEQN,"HIST(CUST3)",MAXBINS,100,MAX_EVENTS,1000,CENTER,0E-3,WIDTH,1,VERT,LINTD:DEF EQN,"PERTRACE(C2)",PTR_TYPE,AVGPACU 1,AMPL,C1PACU 2,SDEV,C1PACU 3,MAX,C3PACU 4,FALL,C1PACU 5,WIDLEV,C1,POS,0E-3 V,1 DIV


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The custom parameter (PACU) settings correspond to the fivelines displayed below the graph, as shown in the example at left.

The figure below shows one use of the CustomDSO file forcompletely customizing the root menu of the scope. Each user-created menu in this example sets up a series of specific testsincluding mask and parameter testing on multiple waveforms.An experienced scope user can easily create a semi-automatedtest sequence that will permit users with limited experience tooperate the most advanced features of the scope.

Example of a CustomDSO generated test, where the DSOmenus set up specific tests involving mask and parametertesting on multiple waveforms

CustomDSO is based on ASCII text files labeled with a .dsoextension. Each of the .dso files contains a series of remotecommands. These files are accessed by the scope throughfloppy disk, PC card, hard disk, or ScopeExplorer. Whenpowered on, the scope looks for the primary file, named'AUTOEXEC.DSO' located in the LECROY_1.DIR directory, andexecutes the commands found in the file. The commands in theprimary file can call additional .dso files, so you can implementrelatively complex measurement sequences.



You create and edit CustomDSO files in a text editor such asWindows Notepad. The figure below shows a typicalAUTOEXEC.DSO file, used to customize the root menu of thescope v ia the KEY command.

Typical autoexec.dso file showing the initial labeling of theroot menu keys (using the KEY command) and thedestination .dso files for each selection


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Use ScopeExplorer to Set Up files:

An easier way to obtain the more complex commands is to setup the scope function you are interested in and useScopeExplorer (a free utility) to query the command. Then cutand paste the response from ScopeExplorer into the .dso file.Figure INTRO–10 shows an example of recalling the commandto set up trace A to perform the FFT of channel 2, which hadbeen set up manually. The DEFINE? query in the upper half ofthe figure reads the scope's existing setup, which appears in thelower half of the figure as "TA:DEF EQN, … ".

Scope explorer result of querying a scope command

Another way to simplify the initial setup of the scope is to set upall the controls of the scope manually, then save the entire state,using a panel setup to floppy disk.

The remote command: "RCPN DISK,FLPY,"P000.PNL'" readsthe panel setup from the floppy disk and returns the scope to thedesired setup.

The internal Remote Control Assistant (RCA) is a powerful toolfor debugging both remote operation and internal CustomDSOfile operation. RCA is accessible under the Utilities menu,special modes. The figure below shows the use of RCA fordebugging a command that is trying to turn on a non-existenttrace.

CustomDSO files offer the opportunity to create custom defaultsetups, prov ide semi-automated prompted operation, or createshortcuts to commonly used features.



Example of the Remote Control Assistant display showingan error (trace header, TE, names a trace that does notexist)


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WAVEFORM HISTORY Display Signal Changes Over Time

Analog Persistence and History mode are tools used to acquireand display how a signal changes over time. These featureswork in a highly integrated fashion to produce screen displaysthat show the range and frequency of occurrence of variations inthe signal.

The LeCroy WavePro series of oscilloscopes place both thesefeatures at your fingertips. Both features can be evoked by

simply pressing , then selecting “History” from the“PERSIST” menu. The figure below shows an intensity-gradedAnalog Persistence display that contains 121 overlaidacquisitions of the leading edge of a pulse waveform. Theintensity grading indicates frequency of occurrence of each edgerate. Included are the time stamps for each acquisition.

Trace D is automatically enabled when you press. When youturn History mode off, Trace D turns off also.

The History button evokes sequence mode and AnalogPersistence to show a history of waveform changes.



Turning off Analog Persistence allows each segment to beviewed individually. Play and Reverse menu selectionscontrol auto-scrolling through all segments

Sequence mode breaks the long acquisition memory of theoscilloscope into as many as 8000 smaller segments. Each ofthese segments is available after the acquisition for indiv idualv iewing, parameter measurements, or waveform math. Andeach segment is indiv idually time stamped with an absolute realtime stamp, time since first trigger, and time between segments.

In this example we can see a single edge that has a slowtransition time. Each of the acquired segments can be v iewedindiv idually by using the oscilloscope’s zoom feature. WithAnalog Persistence turned on, the scope displays all thesegments overlapped. If Analog Persistence is turned off, thezoom display shows each segment indiv idually. An auto-scrolling feature allows you to automatically scan through all thesegments using Play and Reverse. This allows any segmentlocated using the Analog Persistence display to be recovered fordetailed analysis.


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Once such an anomaly is observed it is easy to measure therisetime, using cursors or measurement parameters, then selecta trigger to catch only events with slow risetimes. This type ofevent can be isolated using the Slew Rate trigger, whose setupis shown in the following figure:

Setup for Slew Rate trigger to acquire waveforms withtransition times greater than 1.4 ns

Once the special slew rate trigger has been enabled, running theacquisition again measures the precise time of occurrence ofeach of the slow transition events. This is illustrated in thefollowing figure:



Rerunning a sequence acquisition after turning on SMARTTrigger shows the time of occurrence of each slow edgeevent

The History button consolidates the existing Analog Persistenceand sequence mode features and makes both easily accessiblethrough a direct front panel control.


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Choosing and Navigating in MenusOn-screen menus — the panels running down the right-hand side of the screen — are used to select specificactions and settings. All other on-screen text is forinformation only. The menus are broadly groupedaccording to function. The name of each menu group isshown at the top of the column of menus. Individual menusalso have names in the top of their frames.

Each menu either contains a list of items or options — functionsto be selected or variables to be modified — or performs aspecific action when selected. Menus that perform actions areindicated by capitalized text, as in the example shown at left.

Going to Menus andSelecting from them

When you press a menu entry button, the setup configurationfor its particular group of functions is immediately displayed asa menu group. Once accessed, these menus are controlledusing the menu buttons and the two menu knobs (illustrated atleft).

A menu button is active, and you can press it to makeselections, whenever a menu appears beside it. The two menuknobs work together with the two menu buttons to which theyare joined by lines. Both knobs control the menus currentlyshown beside them. Buttons and knobs are used either forselecting entire menus, particular items from menus, for movingup or down through menu lists, or for changing the displayedvalues.

Some menus have others behind them whose presence isindicated by a heavy outline or shadow on the upper edge of themenu box, as illustrated at left. Pressing the correspondingmenu button reveals the lower-level menu. Pressing theRETURN button redisplays the upper-level one.

Changing a menu value normally changes the screen, as the newvalue is immediately used in acquisition settings, processing ordisplay.



Setting Menu Options The activated selection is highlighted in the menu. Press thecorresponding menu button: the field will advance to highlightand select the next item on the menu. However, if there is onlyone item on a menu, pressing its button will have no effect.

When a menu is associated with one of the two menu knobs,turning this knob in one direction or the other will cause theselection to move either up or down the list in the menu.

Menus that span two menu buttons can be operated using bothbuttons. Pressing the lower of the two will move the highlightingforward — down the list — while pressing the upper will movethe selector back up the list.

An arrow on the side of a menu frame indicates that by pressingthe button beside this arrow, the selection can be moved furtherup or down the list. The arrow’s direction shows whether thehighlighting selector will move up or down. Arrows may alsoindicate items that are not v isible, either above or below on thelist. The respective arrow will disappear when the selection is atthe very beginning or end of the list.

As in the examples at left, some menu button and knobcombinations control the value of a continuously adjustablevariable. The knob is then used to set its value, while the buttoneither selects a value or makes a simple change in it.

Still other menu button and knob combinations control the valueof several continuously adjustable variables, with the knob usedto set the value and the button to highlight it.

Note: When the oscilloscope is placed in a remote state,the REMOTE ENABLE menu is displayed. It will containthe command “GO TO LOCAL,” which is activated by amenu button if the action is possible. This is the onlymanual way to turn off the REMOTE ENABLE menu. TheDDA need not be in the remote state to accept remotecommands.


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SYSTEM SETUP and Menu ControlsBesides the menu buttons and knobs described on theprevious pages, the SYSTEM SETUP controls include themenu entry buttons and other buttons for copying displays,reporting instrument status, and restarting multipleacquisition operations.

is used to return to the preceding displayed menu group.Or it returns the display to a higher-level or primary menu. But whenpressed at the highest possible menu level, the button switches offthat menu.

Each of the dark-gray menu entry buttons activates a major set ofon-screen menus (those menu entry buttons represented in theother control groups are described in the following chapters).

DISPLAY

gives you access to the “DISPLAY SETUP” group ofmenus, controlling display mode, grids, intensities, Dot Join, andPersistence menus (see Chapter 18).

UTILITY

gives you access to the “UTILITIES” menus, which controlhard-copy setups, GPIB addresses, and special modes of operation(see Chapter 19).

WAVESTORAGE

enables you to store and recall waveforms to or fromfloppy disk or optional PC card.

CURSORS

gives you access to the “WAVE PILOT” menus, whichincludes the CURSORS setup menus used for making precisecursor measurements on traces, and enables precise parametermeasurements and pass/fail testing (see Chapter 21).



PANELS

gives you access to the “PANEL SETUPS” menus forsav ing and recalling a configuration of the instrument (seeChapter 22).

SCOPESTATUS

gives you access to the “STATUS” screen, which showssummaries of the instrument’s status for acquisition, system,and other aspects (see Chapter 23).

PRINT SCREEN

PRINTSCREEN

Prints or plots the screen display to an on-line hard-copy device v ia the GPIB, RS-232-C, or Centronics interfaceports, or directly to a built-in thermal graphics printer. Hardcopies can also be generated as data files onto floppy, memorycard, or portable hard disk.

When

PRINTSCREEN

is pressed, all displayed information will becopied. However, it is possible to copy the waveforms withoutthe grid by turning the grid intensity to 0 with the “Display Setup”menu.

While a screen dump is taking place — indicated by the on-screen “PRINTING” or “PLOTTING” message — you can cancelit by pressing PRINT SCREEN a second time. It takes a moment forthe buffer to empty before copying stops. See Chapter 19.

CLEAR SWEEPS By resetting the sweep counter(s) to zero,

CLEARSWEEPS

restartsoperations that require several acquisitions (sweeps) includingaveraging, extrema, persistence, parameter statistics, andpass/fail testing.


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Press the blue AUTO SETUP button to automatically scalethe timebase, trigger level, offset, and volts/div to provide astable display of repetitive signals.

This button operates only on active channels. If nochannels are switched on, and no signals are detected,AUTO SETUP will operate on all channels, switching all ofthem on. If signals are detected on several channels, thechannel with the lowest number determines whichtimebase and trigger source are selected for setup.

Signals detected must have an amplitude from 5 mV to40 V, a frequency greater than 50 Hz, and a duty cyclegreater than 0.1%.

Resetting the Scope To perform a general reset of the instrument,s imultaneously press the AUTO SETUP, top menu,and RETURN buttons:

+ +

The DDA will revert to its default power-upsettings.



Screen Topography

The grid area of the screen and the fields surrounding it provide a variety of usefulinformation, and specific commands and functions.


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Real-Time Clock: Powered by a battery-backed real-time clock,this field displays the current date and time.

Displayed Trace Label: This field indicates each channel orchannel displayed, the time/div and volts/div settings, and cursorreadings when applicable. It indicates the acquisition parametersset when the trace was captured or processed, whereas theAcquisition Summary field (see below) indicates the currentsetting.

Acquisition Summary: This field shows the timebase, volts/div ,probe attenuation, and coupling for each channel, with theselected channel highlighted. It indicates the current setting,whereas the acquisition parameters that were set when the tracewas captured or processed are indicated in the Displayed Tracelabel (above).

Trigger Level: The arrows on both sides of the grid mark thetrigger voltage relative to ground potential.

Trigger Delay: Located below the grid, this field indicates thetrigger time relative to the trace. The delay can be adjustedfrom zero to ten grid div isions (pre-trigger), or zero to − 10 000(post-trigger) off-screen. The pre-trigger delay appears as theupward-pointing arrow, whereas post-trigger is given as a delayin seconds.



Trigger Status: This field shows sample rate and trigger re-arming status (AUTO, NORMAL, SINGLE, STOPPED). Thesmall rectangle flashes to indicate that an acquisition has beenmade.

During an acquisition, the small box to the left of the rearmingstatus indicates when an intermediate acquisition occurs. Thisfeature helps monitor the trigger rate before the waveform isreconstructed.

For NORMAL status, the message “SLOW TRIGGER” appearsin the field when needed.

For slow acquisition, the message “SLOW UPDATE” appears asa reminder that it will take time for a new waveform to becompleted.

The region just to the left of the trigger status field may containmessages indicating lengthy processes such as FFT calculationsor screen dumps under way.Trigger Configuration: This field contains an icon indicating thetype of trigger, and prov ides information on the trigger’s source,slope, level and coupling, and other information whenappropriate.

Trace and Ground Level: This is the trace number and ground-level marker.

Other Screen Regions(not shown)

Time and Frequency: This area displays the time andfrequency relative to cursors below the grid. For example, whenthe absolute time cursor (the cross-hair) is activated by selectingit from the “MEASURE” menu group, this field displays the timebetween the cursor and the trigger point.

Message: This area above the grid is used to display a varietyof messages including warnings, system indications, and titlesshowing the instrument’s current status.


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About this ManualLike the WavePro scope itself, this manual is designed to makeyour measurements as easy as “1–2–3.” Each section showsyou step by step how to use the oscilloscope to solve simple orcomplex problems.

Use the manual with the WavePro DSO in front of you. Thenyou’ll see clearly just what is being referred to; and you canimmediately put into action what is described.

The manual has four main parts:

Part One, “Getting Started,” describes basic operations for newusers. It explains the most important WavePro DSO featuresand shows you how to apply them.

Part Two, “Looking Deeper,” goes into more detail. It explainshow to perform complex measurements using more advancedWavePro DSO functions. It also looks more deeply intooperations covered in Part One. Use it for tackling demandingtasks, or as a reference for a better understanding of how yourscope works.

Part Three, "Wave Analyzer," explains the use of the WAVAoption. By means of enhanced histograms and statisticalanalysis, this option gives you even more analytical capability.

Part Four, "Ethernet Option," explains how to operate yourWavePro DSO through a LAN.

As an additional guide, each chapter is prefaced by a summaryof its contents.

Watch for panels and sections throughout the manual, markedby these icons:

TIPs offer additional hints on how to get the most out ofWavePro DSO actions or features.

NOTEs bring to your attention important information youshould know.

The sections marked by the magnifying glass, andprinted in italic text, “zoom” on particular topics. They offer moreinformation on the subject, where appropriate.



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