Agilent Technologies 6000 Series manual Counter, Duty Cycle, Frequency

Page 244

5 Making Measurements

Counter

The 6000 Series oscilloscopes have an integrated hardware frequency counter which counts the number of cycles that occur within a period of time (known as the gate time) to measure the frequency of a signal.

The gate time for the Counter measurement is automatically adjusted to be 100 ms or twice the current time window, whichever is longer, up to 1 second.

The Counter can measure frequencies up to the bandwidth of the oscilloscope. The minimum frequency supported is 1/(2 X gate time).

The measured frequency is normally displayed in 5 digits, but can be displayed in 8 digits when an external 10 MHz frequency reference is provided at the 10 MHz REF rear panel BNC and the gate time is 1 second (50 ms/div sweep speed or greater). See (“To supply a sample clock to the oscilloscope” on

page 336.)

The hardware counter uses the trigger comparator output. Therefore, the counted channel’s trigger level (or threshold for digital channels) must be set correctly. The Y cursor shows the threshold level used in the measurement.

Any channel except Math can be selected as the source.

Only one Counter measurement can be displayed at a time.

Duty Cycle

The duty cycle of a repetitive pulse train is the ratio of the positive pulse width to the period, expressed as a percentage. The X cursors show the time period being measured. The Y cursor shows the middle threshold point.

+ Width

Duty cycle = ------------------- X 100

Period

Frequency

Frequency is defined as 1/Period. Period is defined as the time between the middle threshold crossings of two consecutive, like-polarity edges. A middle threshold crossing must also travel

244	6000 Series Oscilloscope User’s Guide

Image 244

Contents Agilent InfiniiVision Series Oscilloscopes Newer version of this manual may be available at Agilent Technologies, IncThis User’s Guide… Series Oscilloscope User’s Guide Secure Environment Mode Option 100 MHz 300 MHz 500 MHz GHzGSa/s Oscilloscope History ActionUpgrade Options Memory Depth Option NumbersMaximum Memory Depth Mpts Licensed Option OrderOrder-Only Options Using this book with the 6000L Series oscilloscopes Built-in Quick HelpDigital Channels Abbreviated instructions for pressing a series of keysContents Maximum input voltage for analog inputs Using the analog channels To set up the screen saverTo perform service functions To restore the oscilloscope to its default configurationTo switch all digital channels on or off To switch groups of channels on or offTo switch a single channel on or off Interpreting the digital waveform displaySetting Up the Oscilloscope and the VPT1000 Define the optional Reset on stageAdjust the trigger level Hex Bus Pattern TriggeringTo use TV triggering Source frequency/8FFT Measurement FFT OperationUsing the XGA video output Varying the intensity to view signal detailSelecting the Acquisition mode Peak Detect ModeTo decode I 2 C data To decode LIN dataTo decode UART/RS232 data UART/RS232 TotalizerWaveform Trace and Oscilloscope Setup Choosing save settingsTo save a waveform and/or setup to a USB device To recall waveform trace and/or oscilloscope setupIndex Remote interface Using Quick HelpTo calibrate the probes Getting Started Getting Started To inspect package contents Oscilloscope probes 6000A Series OscilloscopeMSO models only 6000A Series Option BAT Oscilloscope Package contents for 6000L Series oscilloscopes 6000L Series OscilloscopeAccessories available Model DescriptionActive Probes Supported on To adjust the 6000A Series handle To mount the oscilloscope in a rack To mount the 6000A Series oscilloscope in a rackTo mount the 6000L Series oscilloscope in a rack Tools required not suppliedStep If needed T E 6000A Ventilation Requirements Ventilation requirements6000L Ventilation Requirements AC-Powered 6000 Series To power-on the oscilloscopeBattery-Powered 6000A Series Operating with the Internal Battery Vrms, the oscilloscope must be grounded through its groundGround Post Ground post on rear panelCharging the Battery Operating with the Automotive Power Adapter CableReplacing the Battery Indicator will lightPower Cords Plug Type Cable Part NumberRemote interface Detailed Connectivity InformationTo establish a LAN connection 6000A Series To establish a LAN connection 6000L Series HostnameT E To establish a point-to-point LAN connection Stand-alone connection to a PCTo use the Web interface Controlling the oscilloscope using a Web browser Operating the oscilloscope using a Web browserT E Setting a password StepSelect the Modify Configuration button Main Menu Function Keys Identify Function Scrolling and Monitor ResolutionIdentification Option Printing the oscilloscope’s display from a web browser LAN see the Agilent Technologies USB/LAN/GPIB InterfacesMaximum input voltage in 50 Ω mode To connect the oscilloscope probesTo verify basic oscilloscope operation Press AutoScaleSeries Oscilloscope User’s Guide To compensate the oscilloscope probes Perfectly compensated Over compensated Under compensatedTo calibrate the probes Passive Probes SupportedPassive Probes Passive Probes Quantity SupportedBy 300 MHz, 500 MHz, and 1 GHz Bandwidth Models Active Probes SupportedActive Probes Quantity Supported By 100 MHz Bandwidth Models Active Probes for All 6000 Series OscilloscopesTo view Quick Help on 6000L Series oscilloscopes Using Quick HelpTo view Quick Help on 6000A Series oscilloscopes Quick Help Languages Getting Started Front-Panel Controls Front Panel 6000L Series Oscilloscope ControlsRear Panel Front and Rear Panel Controls and Connectors Channel Input BNC Connector Probe Compensation TerminalsInfiniiVision 6000 Series Oscilloscope Programmer’s Quick 6000A Series Oscilloscope Front-Panel Controls Press Utility & I/O & Show I/O Config Graphic Symbols in Softkey MenusConventions Channel 6000A Series Oscilloscope Front Panel Front Panel Controls Printing Data, starting onFront-Panel Controls Series Oscilloscope User’s Guide Horizontal Sweep Speed Control Series Oscilloscope User’s Guide Trigger InputInterpreting the display SoftkeysTo adjust the display grid graticule intensity To adjust the waveform intensity6000A Series Front-Panel Operation To start and stop an acquisition To make a single acquisition Memory Depth/Record Length Run/Stop versus SingleSingle RunningTo pan and zoom Auto SingleChoosing Auto trigger mode or Normal trigger mode Using AutoScalePassive Probes To set the probe attenuation factorExample Manually Setting the Probe Attenuation Factor Active ProbesUsing the analog channels Channel TriggerVolts/div Source Bandwidth Channel InvertTurning channels off MHz bandwidth oscilloscope is fixed at 1 MΩ . Therefore, Impedance selection is not available on these modelsOscilloscope to the correct impedance Measurement HintsFront-Panel Controls Save/Recall&Default Setup Units Factor ProbeTo set up the Horizontal time base Main modeSeries Oscilloscope User’s Guide Front-Panel Controls Zoom mode Press Menu/ZoomThese markers define Time/div for Delay time Beginning and end Zoom sweep Main sweepZoom sweep window Select main or Zoom sweepRoll mode XY mode Axis Input in XY Display Mode BlankingTo make cursor measurements To make automatic measurements Using Labels To turn the label display on or offTo assign a predefined label to a channel Label Assignment Auto-Increment Features To define a new labelPress Utility→ File Explorer To load a list of labels from a text file you createLabel List Management To reset the label library to the factory default Defaulting labels without erasing the default libraryTo print the display Press Utility &Options &PreferencesTo set the clock Press Utility&Options&ClockSet Set Day set Hour setTo set up the screen saver Screen Saver is disabled on 6000L modelsTo set the waveform expansion reference point User Calibration To perform service functionsAbout User Cal Return to Self Test Oscilloscope Status To perform User Cal Longer cable To Trig OUT To ChannelUser Cal Status User Calibration cable for 4-channel oscilloscopeSelf Test About OscilloscopeInstalled licenses To restore the oscilloscope to its default configuration Viewing and Measuring Digital Signals Supplied with the mixed-signal oscilloscope To connect the digital probes to the circuit under testChannel Pod Ground Circuit GrabberSignal Lead Ground Lead Grabber Acquiring waveforms using the digital channels Signals GroundTo display digital channels using AutoScale ExampleSeries Oscilloscope User’s Guide 117 Activity indicator Interpreting the digital waveform displayTo switch groups of channels on or off To switch all digital channels on or offTo switch a single channel on or off To change the displayed size of the digital channels To reposition a digital channelThreshold you To change the logic threshold for digital To change the logic threshold for digital channelsLogic family Threshold Voltage To display digital channels as a bus Bus softkeyBus1/Bus2 Select Return to Softkey Individual Channel Base Channels GroupUsing cursors to read bus values BinaryBinary or Hex Bus values are displayed when using Pattern trigger 126 Triggering the Oscilloscope Triggering Features SPI USBSee Using Serial Decode on page 271 for more information To select the Mode and Coupling menu Selecting Trigger Modes and ConditionsAuto mode Trigger modes Normal and AutoNormal mode To select trigger Coupling To select trigger Noise Rejection and HF rejectionHoldoff To set Holdoff200 ns 600 ns Holdoff Operating Hints External Trigger input External Trigger Probe SettingsChannel oscilloscope External Trigger input Functions when the oscilloscope is powered on To the oscilloscope may occur Trigger Types MegaZoom Technology Simplifies TriggeringEdge Trigger To use Edge triggeringSlope Trigger level adjustment To use Pulse Width triggering Polarity TriggerQualifier Polarity10 ns 10 ns Trigger Qualifier time set softkey10 ns 15 ns To use Pattern triggering Pattern SelectedTrigger Channel Rising orSpecifying an Edge in a Pattern Hex Bus Pattern Triggering Bus1 or Bus2For can decode setup see To use can triggeringCan trigger Signal sourceBits Condition Selector Rate PointOne Bit NormalDuration Selected To use Duration triggeringLevel Qualifier Qualifier time set Return to Select Series Oscilloscope User’s Guide 153 When the duration trigger occurs To use FlexRay triggering Modes of VPT1000 Control/OperationSetting Up the Oscilloscope and the VPT1000 Connecting the Oscilloscope and the VPT1000Accessing the VPT1000 Menu PC Controls the VPT1000Specifying the VPT1000 LAN Address Sync Mode LAN AddressStruct Selecting the VPT1000 Control/Operating Mode Asynchronous or Synchronous Mode In addition to the logic Restore synchronizationMb/s, or 10 Mb/s Accessing the FlexRay Trigger Menu Triggering on FlexRay Frames, Times, or ErrorsTriggering on FlexRay Frames Oscilloscope in asynchronous mode Triggering on the FlexRay Time ScheduleTriggering on FlexRay Errors All ErrorsMultiple errors exist For I2C decode setup see To use I2C triggeringClock Start Address Ack Data Frame Start Addr7 Read Ack Data or Frame Start Addr7 Frame Start Addr7 Read Ack Data Ack Data2 or Frame Write Address R Ack1 Address Ack2 Data1st byte 2nd byte 26th clock edgeSeries Oscilloscope User’s Guide 169 To use Nth Edge Burst triggering Idle Time TriggerEdge Nth Edge Burst triggerAssign Channels Edge Select To use LIN triggering For LIN decode information seeSync FieldSignal Condition Baud rate LIN triggerSource Signal Sample Standard Menu Baud rate Point Selector BreakTo use Sequence triggering Find? Trigger on? Reset on? YesStart Yes Sequence Selected TermDefine the Find stage Edge Pattern 1 and EdgeDefine the Trigger on stage Edge Pattern 2 and Edge Nth Edge Nth Edge 2 no re-find Define the optional Reset on stage Edge 1 or Pattern 1 and Edge TimeoutAdjust the trigger level To use SPI triggering For SPI decode information seeFraming, or Data channel Bit Set allValue Data bits To valueClock Data Frame by Channel Slope ConditionSeries Oscilloscope User’s Guide 185 186 Resetting all bits in the serial data string to one value To use TV triggeringSource Sync Selected Trigger ChannelChannel Polarity Provide Correct Matching Standard Type Sync Pulse190 Example exercises To trigger on a specific line of videoLine numbers for each EDTV/HDTV video standard Video standard Field Alt FieldLineAlternate Alternate TriggeringTo trigger on all sync pulses Triggering on All LinesTo trigger on a specific field of the video signal Triggering on FieldTo trigger on all fields of the video signal Triggering on All FieldsTo trigger on odd or even fields Series Oscilloscope User’s Guide 197 Half-field holdoff time Standard TimeTo use UART/RS232 triggering For UART/RS232 decode setup seeTrigger softkey 200 Series Oscilloscope User’s Guide 201 202 Series Oscilloscope User’s Guide 203 USB trigger Trigger on Signal + source Source To use USB triggeringEnd of packet trigger Bus Idle Data sourceSeries Oscilloscope User’s Guide 205 Trigger Out connector TriggersSource frequency Source frequency/8Making Measurements Post Acquisition ProcessingTo use the XY horizontal mode Example of centering a signal on the display Signal centered on the displayCursors set on displayed signal Series Oscilloscope User’s Guide 211 Signals are 90 out of phase Math Functions Math Operating HintsMath Scale and Offset are Set Automatically Math scale and offsetMath function Units Multiply Multiply Channel Waveform Math Function ScaleSubtract Subtract Channel Waveform ScaleDifferentiate Channel Dt waveform Math Source Function Select Scale Integrate Integrate and Signal Offset Channel Dt waveform Channel 1 0 Scale Source SelectFFT Measurement FFT UnitsDC Value AliasingAliasing Source Frequency Center Preset Span FFT OperationSpectral Leakage Select Span Frequency CenterWindow OffsetScale and offset considerations FFT Measurement Hints FFT measurementsSeries Oscilloscope User’s Guide 229 Square Root Channel √ waveform Scale √ Source SelectCursor Measurements Series Oscilloscope User’s Guide 233 234 Series Oscilloscope User’s Guide 235 Cursor Examples Cursors measure frequency of pulse ringingSeries Oscilloscope User’s Guide 237 Moving the cursors together to check pulse width variations Phase and Delay Automatic MeasurementsTime Measurements Voltage MeasurementsSettings Thresholds To make an automatic measurementPreshoot and Overshoot Erase all Additional Changing default thresholds may change measurement results To set measurement thresholdsSource Threshold Lower Middle Upper Return to Select Type Absolute threshold hintsTime Measurements FFT measurementsRise Time Thresholds Upper Middle Lower + WidthDuty Cycle CounterFrequency Period Isolating event for Frequency measurementFall Time Rise Time+ Width WidthDelay and Phase Measurements DelaySource Delay At MinPhase Delay MeasurementPeriod Source Delay Voltage MeasurementsMath Measurements and Units Maximum Top Amplitude Peak-PeakMinimum Digital channel voltage measurementsAmplitude AverageBase MaximumRMS Std Deviation∑ xi Top Isolating area for Top measurementOvershoot and Preshoot Measurements PreshootLocal Maximum Preshoot Top PreshootOvershoot Overshoot Local Maximum Top Base Local MinimumDisplaying Data AntialiasingPan and Zoom ZoomTo pan and zoom a waveform To set the waveform expansion reference pointUsing the XGA video output AntialiasingDisplay Settings Infinite persistenceGrid intensity Vectors connect the dotsAccumulating multiple acquisitions Clearing stored infinite persistence waveformsVarying the intensity to view signal detail Using Vectors Display menuAmplitude Modulation with Noise Shown at 100% Intensity Acquisition Modes Selecting the Acquisition modeAt Slower Sweep Speeds Normal Mode Peak Detect ModeHigh Resolution Mode Agilent 6000 Series Model Numbers and Sampling RatesAveraging Mode # Avgs=1GSa/s Sample Rate # AvgsTo use the Averaging mode Random noise on the displayed waveformRealtime Sampling Option 128 Averages used to reduce random noiseRealtime Sampling and Oscilloscope Bandwidth Using Serial Decode For I 2C triggering setup see Display Decode Signal Return to Mode Setup menuTo decode I2C data Decode I 2C data while LIN triggering is selectedSeries Oscilloscope User’s Guide 273 Interpreting Decoded I2C Data Series Oscilloscope User’s Guide 275 For SPI triggering setup see To decode SPI dataSignal Clock Frame by Signal Edge Option278 Interpreting Decoded SPI Data 280 For can triggering setup see To decode can dataRate Sample Return to Signal Source Point Series Oscilloscope User’s Guide 283 Interpreting Decoded can Data Active Error Frame red CRC blue Data white Data Length Code blueTypes of Frames Can TotalizerCounters Total Frame Overload Error Frame Count Frame Count PercentageFor LIN triggering setup see To decode LIN dataLIN trigger Decoded LIN data BaudSync Return to Source Rate Sample Standard Break Point Selection290 Series Oscilloscope User’s Guide 291 Interpreting Decoded LIN Data Series Oscilloscope User’s Guide 293 Display Decode VPT1000 Reset Return to Mode Menu Counters To decode FlexRay dataSeries Oscilloscope User’s Guide 295 Trailer Interpreting Decoded FlexRay Frame DataHeader CRC blue Interpreting Decoded FlexRay Time Data Time-Schedule DecodeFlexRay Totalizer Counters softkeyCount Total Frame Null FramePercent To decode UART/RS232 data For UART/RS232 triggering setup seeSelected Signal Bus Base Value UART/RS232 trigger Define Display Framing302 Series Oscilloscope User’s Guide 303 Interpreting Decoded UART/RS232 Data Series Oscilloscope User’s Guide 305 Tx Frame Rx Frame UART/RS232 TotalizerCount Percent To reduce the random noise on a signal HF RejectPress Mode/Coupling&HF Reject DB down pointLF Reject Noise rejectionPress Mode/Coupling&Coupling&LF Reject DB down point Pass BandSeries Oscilloscope User’s Guide 309 Using peak detect mode to find a glitch 15 ns Narrow Pulse, 20 ms/div, Peak Detect ModeSeries Oscilloscope User’s Guide 311 How AutoScale Works Undo AutoScalePreserving the Acquisition Mode During AutoScale Specifying the Channels Displayed After AutoScale314 Saving and Printing Data Printing the oscilloscope’s display Supported PrintersPrinting the oscilloscope’s display Print optionsChoose Options Select Printer Factors Color orPalette Selecting print optionsGraticule Not Inverted Supported Printers Series Oscilloscope User’s Guide 319 Can be saved to Saving oscilloscope dataType of Data Selecting a destination for your saved data Overwriting a file Selecting a file nameCreating a new file name Series Oscilloscope User’s Guide 323 Display Image and Waveform Data Files Waveform Trace and Oscilloscope SetupDisplay Image and Waveform Data File Formats Factors Choosing save settingsInvert Graticule Colors Palette Length ControlTo save a waveform and/or setup to a USB device Trace, or Trace and Setup To recall waveform trace and/or oscilloscope setupFile explorer Regarding USB Ports To use the file explorer Press Utility&File ExplorerSecure Environment Mode Option Ordering the Secure Environment Mode Option Ordering the Secure Environment Mode OptionTo set up the I/O port To supply a sample clock to the oscilloscopeSoftware and firmware updates Utility&Options&Features&Show license informationUtility&Service&About Oscilloscope Upgrading to an MSO or adding memory depthTo set up the I/O port Using the 10 MHz reference clock Sample clock and frequency counter accuracySupplying an external timebase reference To supply a sample clock to the oscilloscopePress Utility&Options&Rear Panel&Ref Signal Reference signal locked MHz input mode selectedTo check warranty and extended services status To synchronize the timebase of two or more instrumentsTo clean the oscilloscope To return the instrumentInput Impedance Series Oscilloscope User’s Guide 341 Probe Grounding Impedance versus Frequency for Both Probe Circuit ModelsVn Common Mode Probe Probe NBest Probing Practices To replace digital probe leads Digital Probe Replacement PartsPart Number Description Binary Data .bin Binary Data in MatlabBinary Header Format File HeaderWaveform Header 348 Series Oscilloscope User’s Guide 349 Example Program for Reading Binary Data Waveform Data HeaderExamples of Binary Files Single Acquisition Multiple Analog ChannelsSingle Acquisition All Pods Logic Channels Minimum and Maximum Values in CSV Files 1000ns ⋅ 4Gsa ⁄s = 4000samples354 Power and Environmental Conditions Power Requirements Measurement Category Measurement CategoryMeasurement Category Definitions Transient Withstand Capability With 50 Ω input 5 VrmsEnvironmental Conditions Specifications SpecificationsAcknowledgements Contact us AmericasAsia Pacific Europe362 Index Index Series Oscilloscopes User’s Guide 365 Modify softkey, 39 MSO, 4 Series Oscilloscopes User’s Guide 367 USB

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