User Manual

TDS3LIM

Limit Test

Application Module

071-0934-01

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Contents

Safety Summary 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Installing the Application Module 5. . . . . . . . . . . . . . . .

Limit Testing Concepts 5. . . . . . . . . . . . . . . . . . . . . . .

TDS3LIM Overview 8. . . . . . . . . . . . . . . . . . . . . . . . . . .

Accessing Limit Test Menus 9. . . . . . . . . . . . . . . . . . . .

Creating a Limit Test Template 11. . . . . . . . . . . . . . . . . .

Selecting a Limit Test Input 14. . . . . . . . . . . . . . . . . . . .

Selecting Limit Test Responses 15. . . . . . . . . . . . . . . . .

Starting Limit Testing 16. . . . . . . . . . . . . . . . . . . . . . . . .

TDS3LIM Conventions 17. . . . . . . . . . . . . . . . . . . . . . . .

Menus 19. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

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Safety Summary

To avoid potential hazards, use this product only asspecified. While using this product, you may need toaccess other parts of the system. Read the General SafetySummary in other system manuals for warnings andcautions related to operating the system.

Preventing Electrostatic Damage

CAUTION. Electrostatic discharge (ESD) candamage components in the oscilloscope and itsaccessories. To prevent ESD, observe theseprecautions when directed to do so.

Use a Ground Strap. Wear a grounded antistatic wrist strapto discharge the static voltage from your body whileinstalling or removing sensitive components.

Use a Safe Work Area. Do not use any devices capable ofgenerating or holding a static charge in the work areawhere you install or remove sensitive components.Avoid handling sensitive components in areas that have afloor or benchtop surface capable of generating a staticcharge.

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Handle Components Carefully. Do not slide sensitivecomponents over any surface. Do not touch exposedconnector pins. Handle sensitive components as little aspossible.

Transport and Store Carefully. Transport and store sensitivecomponents in a static-protected bag or container.

Manual Storage

The oscilloscope front cover has a convenient place tostore this manual.

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Installing the TDS3LIM Application Module

Refer to the TDS3000, TDS3000B, and TDS3000CSeries Application Module Installation manual forinstructions on installing and testing the applicationmodule.

Limit Testing Concepts

Limit testing is the ability to compare an active signalwith a template waveform. The following figure showsan active waveform (dark sine wave) being compared toa template waveform (shaded area).

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Any part of the active waveform that exceeds the tem-plate waveform’s envelope is a limit test waveformviolation, which the oscilloscope highlights. You can setthe oscilloscope to respond to a limit test violation bystopping limit testing, emitting a beep, and so on. Thefollowing figure shows the highlighted (black) part ofthe active waveform that exceeds the limit test envelope.

A template is an envelope waveform that consists ofminimum/maximum (min/max) pairs of sample points.Template envelope waveforms created from 500 pointsource waveforms contain 250 min/max pairs; Templateenvelope waveforms created from10K point waveformscontain 5000 min/max pairs.

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The following figure represents how the oscilloscopecreates the template waveform limit test envelope fromuser-entered vertical and horizontal division units.Division units are referenced to graticule divisions,where 1 major division contains 1000 millidivisions, ormdivs. The minimum mdiv unit is 20, which equals onescreen pixel.

Verticallimits

Horizontallimits

Resultingtemplate

+ =

+ =

When a source waveform is compared with an envelopewaveform, each source waveform sample point value iscompared to the vertical and horizontal min/max valuesof the corresponding envelope waveform sample point.Any source waveform data point that is not equal to orwithin the corresponding template envelope min/maxvalues is a violation.

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TDS3LIM Overview

This section provides an overview of the TDS3LIMLimit Test application module features, and describeshow to access the limit test functions.

You can do the following limit test tasks with theTDS3LIM application module:

� Create and save up to four template waveforms inreference memory. You can create a templatewaveform from either an active input signal or from asaved reference waveform.

� Select the channel to compare to the template. Youcan compare multiple channels to a single templatewaveform, compare each channel to a single templatewaveform, or any combination of the above.

� Set the oscilloscope to respond to waveforms thatexceed the template limits. You can set theoscilloscope to stop acquiring waveforms, save thefailed waveform data to a file, emit a beep, save thescreen image to the hard copy device, or anycombination of the above.

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Accessing Limit Test Menus

You access the TDS3LIM limit test controls from eitherthe limit test QuickMenu or from the Applications menu.The QuickMenu displays a single bottom and side menuthat provides quick access to all limit test functions.

To display the limit test QuickMenu, do the followingsteps:

1 Push theQUICKMENU panel button.

2 Push theMenu bottom button to select Limit Test.The oscilloscope displays the limit test bottom andside menu items.

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The Applications menus provide multiple bottom andside menu items that contain all limit test controls andsettings. The menu items contain text or graphics thatmore fully describe the function of each menu item.

To display the limit test menu items in the Applicationsmenu, do the following steps:

1 Push the UTILITY panel button.

2 Push the System bottom button to select Apps.

3 Push theModule button to select Limit Test. Thebottom and side menus change to show the limit testfunctions.

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Creating a Limit Test Template

You must create a limit test waveform template beforeyou can do limit testing. The TDS3LIM lets you easilycreate a template by using a known good waveform(active or reference), using the vertical and horizontaldivision units to graphically define the template wave-form envelope, and saving the template to referencewaveform memory (Ref1 - Ref4).

To use an active waveform to create a limit test template,do the following steps:

1 Connect a known good waveform to any one of theoscilloscope inputs.

2 Set the oscilloscope horizontal and vertical controls tooptimize the waveform size and position on thescreen.

NOTE. Use the Average acquisition mode tocreate a smoother, cleaner template waveform.You can also save the oscilloscope settings fromstep 2 into setup memory so that later on youcan quickly reload the oscilloscope settings tocorrectly display the incoming waveform forlimit testing.

NOTE. Use Envelope acquisition mode in orderto create template waveforms that includeoccasional overshoots.

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3 Push theQUICKMENU panel button.

4 Push theMenu bottom button to select Limit Test.The oscilloscope displays the limit test bottom andside menu items.

5 Push the Template Source/Destination side button toselect the Source field; use the general purpose knobto select the channel to which the known good signalis connected (Ch1 - Ch4).

You can also create a limit test waveform templatefrom a reference waveform by using the generalpurpose knob to select a reference waveform(Ref1-Ref4).

6 Push the Source/Destination side button to select theDestination field; use the general purpose knob toselect the reference memory location where you wantto store the template waveform (Ref1 - Ref4).

7 Push the ±V Limit side button to select the templatevertical limits field. Use the general purpose knob toset the template waveform envelope vertical limits.Refer to page 6 for an explanation of the limit units.

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8 Push the ±H Limit side button to select the horizontallimits field. Use the general purpose knob to set thetemplate waveform envelope horizontal limits. Referto page 6 for an explanation of the limit units.

9 Push the Store Template bottom button to create thelimit test waveform and save it to the specifiedreference memory location. If the template referencewaveform is currently displayed, the oscilloscoperedraws the reference waveform using the newlystored values.

10 If the template reference waveform is not currentlydisplayed, push the CONTROL bottom button toselectOn. The oscilloscope displays the referencewaveform.

11 If the template reference waveform does not meetyour requirements, repeat steps 7 through 9 to changethe template waveform envelope.

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Selecting a Limit Test Input

To select the channel source for comparing with atemplate, do the following steps (the Limit Test Quick-Menu must still be displayed):

1 Connect the test waveform to any one of theoscilloscope inputs.

2 Set the source waveform horizontal and verticalsettings to the same values that were used to create thetemplate.

3 Push theWaveform Comparisons bottom button forthe test waveform channel to select the limit testtemplate (Ref1 - Ref4).

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Selecting Limit Test Responses

When the active waveform exceeds the template wave-form’s envelope, the oscilloscope can do one or more ofthe following actions:

� Send a hard copy of the screen to a printer or file

� Save the failing test waveform to a file on the drive

� Emit a beep each time the test waveform fails

� Stop waveform acquisition and display the failingwaveform(s)

In the QuickMenu, theOn Violation side menu uses twobuttons, as shown in the following figure.

Select a response

Enable/disable a response

Use the upper menu button to select a response, and thenuse the lower menu button to enable or disable theselected response. You can select and enable any com-bination of responses.

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Starting Limit Testing

After setting up a template waveform, selecting a testwaveform channel or channels, and selecting the oscillo-scope limit test responses, you are ready to start limittesting. To start limit testing, push the CONTROLbottom menu button to selectOn. The oscilloscope startslimit testing, and continues testing until a violationoccurs, at which time the oscilloscope performs theselected response action.

NOTE. If Stop On Violation is not selected, theoscilloscope performs all selected response tasks(such as emit a beep) and then resumes limittesting.

NOTE. If the oscilloscope displays an errormessage stating that limit testing is turned off,check that you have enabled the input signalchannels and that there is a valid limit testwaveform template or templates in the selectedreference memory location(s).

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TDS3LIM Conventions

The following conventions apply to the TDS3LIM LimitTest application module:

� You do not need to display a reference templatewaveform to do limit testing.

� Moving a reference template waveform on thedisplay screen does not change the reference templatewaveform data or the limit test parameters. Limittesting compares active signals to the waveformtemplate data in reference memory.

� When limit test is set to Stop On Violation, theoscilloscope stops signal acquisition and highlightsthe waveform violations.

� While in Limit Test mode, the WAVEFORMINTENSITY knob controls the limit test violationsdisplay decay time. The decay time is the amount oftime that the violation highlighting remains on thescreen. The range of values is zero seconds to alwayson (infinity). The Waveform Intensity knob does notaffect active signal display intensity while LimitTesting is on.

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� If you are using two or more waveform templates at atime in a limit test, all the waveform templates mustuse the same horizontal time base setting.

� Source waveforms you are testing must be set to thesame horizontal and vertical settings used to createthe corresponding template waveform(s).

� When limit test is set to Hard Copy On Violation orSave To Disk, the oscilloscope completes the taskbefore processing any other tasks or continuing signalacquisition.

� Save To Disk saves the waveform data using theformat specified in the SAVE/RECALL > Save

Waveform > To Filemenu. Please check this settingso that you are saving waveform data in yourpreferred format.

� Turning limit testing on sets the signal acquisitionmode to Sample.

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Menus

The following sections list the limit test menus anddescribe each menu function.

Limit Test QuickMenu

The Limit Test QuickMenu displays bottom and sidemenus that provide fast access to all limit test functionson one screen.

Limit Test QuickMenu: bottom menu

Menu item Value Description

CONTROL OFFON

When on, starts limit testing.

WAVEFORMCOMPARISONSCh1, Ch2,Ch3, Ch4

(Ch3, Ch4 on4-channelmodels only)

Ref1-Ref4,None

Assigns a reference memorylocation to a signal input chan-nel. Repeatedly push the menubutton to cycle through theselections. Selecting Nonedisables limit testing on thatchannel.

You can compare each channelto a separate template waveformor compare multiple channels tothe same template.

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Limit Test QuickMenu: side menu

Menu item Value Description

SETUP: OnViolation:

Printer iconDrive iconSpeaker iconStop

When enabled, sets how theoscilloscope responds to limit testfailure.

The four response actions to a limittest failure are: send a screencapture to the hard copy device,save the failing waveform data to afile on the drive, emit a beep foreach failure, and stop waveformacquisition.

This menu uses two side menubuttons. The upper button selectsa response in the side menu, andthe lower button enables or dis-ables the current selection (seepage 15). You can select andenable any combination of re-sponses.

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Limit Test QuickMenu: side menu (cont.)

Menu item DescriptionValue

TEMPLATE:Source

Destination

Ch1-Ch4,Ref1-Ref4

Ref1-Ref4

Sets the waveform source fromwhich to create a limit test tem-plate waveform, and the destina-tion reference memory location inwhich to store the template wave-form. Pushing the side menubutton toggles between selectingthe Source and Destination menufields. Use the general purposeknob to select the value for eachfield.

TEMPLATE:±V Limit±H Limit

0 to 5 div Sets the vertical and horizontaldivision units used to create atemplate waveform envelope.Pushing the side menu buttontoggles between selecting the±V Limit and the ±H Limit menufields.Use the general purpose knob toselect the value for each field. Theminimum increment value is20 mdiv, or one pixel. Refer topage 6 for an explanation of thetemplate envelope.

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Apps Module Limit Test Menu

The TDS3LIM module adds a limit test menu item to theUTILITY > System > Apps > Module menu. Thefollowing table describes the new limit test bottom andside menu functions.

UTILITY > System > Apps > Module Menu

Bottom Side Description

Limit TestSetup

Limit TestOn Off

Turns limit testing on or off.p

Stop OnViolationOn Off

When On, the oscilloscope stopswaveform acquisition when there isa limit test failure on any channel.The input waveforms and violationsremain displayed on the screen.

Beep OnViolationOn Off

When On, the oscilloscope beepswhen there is a limit test failure onany channel.

Hard Copy OnViolationOn Off

When On, the oscilloscope sendsan image of the screen to the hardcopy device or file for each occur-rence of a limit test violation.

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UTILITY > System > Apps > Module Menu (cont.)

Bottom DescriptionSide

Limit TestSetup(cont.)

Wfms To DiskOn ViolationOn Off

When On, the oscilloscope savesthe violating waveform(s) data to afile on the drive for each occurrenceof a limit test violation.

Limit TestSources

CompareCh1-Ch4ToRef1-Ref4,None

Selects which input channel tocompare to which limit test tem-plate stored in reference memorylocations Ref1 through Ref4.Selecting none disables limit testingon that channel. Repeatedly pushthe side menu button to cyclethrough the possible selections.You can compare each channel to aseparate template waveform, orcompare multiple inputs to thesame template.

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UTILITY > System > Apps > Module Menu (cont.)

Bottom DescriptionSide

CreateLimit Testtemplate

TemplateSource

Selects which signal source to useto create the limit test template.Valid sources are channels 1through 4 and reference waveformmemory Ref1 through Ref4.

TemplateDestination

Selects which reference memorylocation to use to store the limit testtemplate. Valid sources are Ref1through Ref4.

±V limit±H Limit

Sets the vertical or horizontal limitsused to create a template wave-form envelope. Use the generalpurpose knob to select the limitvalue.Units are in divisions and rangeUnits are in divisions, and rangefrom zero to five major divisions, inincrements of 20 millidivisions (1pixel). Refer to page 6 for anexplanation of the template enve-lope.

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UTILITY > System > Apps > Module Menu (cont.)

Bottom DescriptionSide

CreateLimit Testtemplate(cont.)

OK StoreTemplate

Stores the template waveformdefined by the source and ±V/Hlimit settings to the specifiedreference memory destination. Thelimit test template is not stored untilyou push this menu button.