Time Base Control, Number of samples | Fluke PM-3390B, PM-3380B

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USING THE COMBISCOPE INSTRUMENTS

3.8 Time Base Control

In the digital mode, the SENSe:SWEep:TIME:AUTO command allows you to enable autoranging of the main timebase (MTB).

3.8.1Number of samples

The TRACe:POINts command allows you to set the number of sample points, which is the total acquisition length for all traces. The number of samples is limited to discrete values; refer to the TRACe:POINts command reference for a detailed specification of these values. After a *RST command, the number of samples is 512.

Note: If the number of samples is changed, the contents of all trace memories is cleared. So, all previously stored traces are lost!

PROGRAM EXAMPLE:

CALL	Send(0, 8, "*RST", 1)	’Acquisition length = 512 samples.
CALL	Send(0, 8, "TRACe:POINts CH1,8192", 1) ’Acquisition lengthd = 8192 samples.

3.8.2Time base speed

The SENSe:SWEep:TIME command specifies the time base of a sweep, which is the time duration of one complete trace acquisition. Because the SENSe:SWEep:TIME values are limited in the digital mode by permitted MTB values, only particular values can be specified with this command. Refer to the SENSe:SWEep:TIME command reference for a detailed specification of these values.

Together with the number of trace points (TRACe:POINTs), the SENSe:SWEep:TIME command determines the Main Time Base (MTB). The MTB is expressed in seconds per division. Since there are 50 points in each division, the MTB can be calculated from the following equation:

MTB = 50 * SENSe:SWEep:TIME / (TRACe:POINts -1 )

Image 61

Fluke PM-3390B, PM-3380B Time Base Control, Number of samples, Time base speed, MTB = 50 * SENSeSWEepTIME / TRACePOINts

Contents

Qvwuxphqw Trademarks About this Manual What this Manual Contains IIIInitializing the CombiScope Instrument Measuring Signal Characteristics Readout of measurement data 15.4.2 Error-reporting using the SRQ mechanism15.1.1 15.1.2 Application Program Examples . . . . . . . . . . . . . A-1 Command Reference VII About this Manual What this Manual Contains About this Manual Preparations for Scpi Programming System setupGetting Started with Scpi Programming Programming environment Commands CommandAddresslist Constant -1 Ffff hex Programming Note Program Example How to identify the CombiScope instrument How to reset the CombiScope instrumentHow to switch between digital and analog mode Initializing the CombiScope Instrument ’Requests for error Error Reporting Channels and memory registers Example Send -- FORMat INT,16 Acquiring TracesFormat of the trace response data is as follows Example Preparations How to acquire a single shot traceThis string data Connect a probe from the Probe Adjust signal to channel How to acquire repetitive traces CONFigure + READ? Measuring Signal CharacteristicsMEASure? INITiate + FETCh? How to make repeated measurements How to make a single shot measurement Introduction Using the Combiscope Instruments Using the Combiscope Instruments TRACe? CH1 Fundamental Programming ConceptsSAV RCL SYSTemKEY DISPlayMENU TRIGgerMeasurement instructions Explanation of the Instrument Model Single function programming using the instrument model Read ← blockdata Instrument setup Instrument setup Front panel simulation MEASureAC? MEASure? query Voltageparameters = expectedvoltage,resolution Benefits of using parametersGeneric form of a measurement instruction is as follows MEASureAMPLitude? ExamplesMEASureVOLTageAMPLitude? 10, @2 MEASureVOLTageFREQuency? 10E6, @3 Waveform measurements Pulse characteristics MEASureRISETIME? 20,80 MEASureFALLTIME? @3Measurefunctionmeasureparameters FTIMe = alias for Falltime RTIMe = alias for Risetime CONFigureAC Customizing settingsSENSeAVERage on SENSeAVERageCOUNT READRISEOVERshoot? CONFigureRISETIMEMultiple measurements READFREQuency? Multiple characteristics from a single acquisitionStarts Acquisition Returns Starts a Next acquisition Returns New Frequency result TRIGgerSOURce BUS Trigger control via GpibINITiate FETChAC? M12,CH2 Fetching characteristics from memory traces Acquisition control Acquisition Using the Combiscope Instruments Trigger Type TriggeringTrigger Source Trigger Level Trigger Coupling Trigger Slope DC Coupling DC Coupling 0 Hz cutoff frequencyAC Coupling 10 Hz cutoff frequency HF-REJECT 30 KHz cutoff frequency LF-REJECT 30 KHz cutoff frequencyVideo triggering Lines per frame NtscPAL Secam OFF Trigger modesLine BUS State Description Commands Trace Pre- and post-triggering External triggering 10 The trace acquisition flow Reading trace acquisitions Repetitive acquisitions Single-shot acquisition 11 Relation between screen position and trace value Conversion of trace data ’Array of 512 integers Byte1 = ASCMID$response$, J For 8-bit sample traces Ps = TsPs = Ts / 25600 * 100 = Ts ’1-byte samples Using the Combiscope Instruments Program Example AVGn = ∑X1 + .. + Xn ⁄ n Averaging Acquisition Data 13 The Trigger Model during acquisition averaging Programming tip Channel Selection 1 AC/DC/ground coupling Signal Conditioning Input impedance Input filteringInput polarity Vertical range and offset Autoranging attenuators Vs = Ts / 200 * PTPeak OFFSetLimitation Number of samples Time Base ControlTime base speed MTB = 50 * SENSeSWEepTIME / TRACePOINts Real time acquisition Ts = sampleindex * SENSeSWEepTIME / TRACePOINts Autoranging time base 16 Definition of a signal period Post Processing How to do post processingSelect the source for the post processing function Send → CALCulateFEED M21 ’M21 = source for CALC1 Mathematical calculations Standard AvailableMath Optional Example Send → TRACe? M21 Check the result of the post processing functionRead ← tracebuffer ’Reads M21 trace Differentiating and integrating traces Mathematical calculations Relative FFT Frequency domain transformationsAbsolute FFT For 16-bit samples Ps = Ts 25600 Trace Point ValuesTrace data Example for attenuator setting 0.5 V/div This can be calculated as a signal levelVrms offset calculation DBm 600Ω offset calculation DBm 50Ω offset calculationDBμV offset calculation DBμV = 1 μV 1.0E-6 V at 50Ω impedance Trace Point Frequencies SettingFs = sampleindex * 1250 / TRACePOINts * MTB Program Example Amplitude belt = peak-to-peak range Histogram functionsFrequency filtering 20 Trace memory control Trace Memory PM33x0B 512 +EXT Channels Memory Registers StandardExtended Trace formatting Copying traces to memory Send → TRACe? CH3 Writing data to trace memory’Queries for CH3 trace Read ← trace block Reading data from trace memory Brightness control Screen/Display FunctionsDisplay functions Menu MEAS1/MEAS2 Data Measurement ValueMeastype,measvalue,suffixunit Description Type Unit Description Cursors DataMath FFT Data Call Send0, 8, DISPlayMENU MEASure Program Example 2 text as block data Display of user-defined textSelection of softkey menus Device Type Print/Plot FunctionsHpgl Hplaser 22 Hardcopy of screen on printer/plotter Auto Calibration Real-Time Clock = okay Status data for the CombiScope instruments Status Reporting Operation status data Digital modeCALibrating RANGing Questionable status data TEMPeratureVOLTage CALibration Status Register Data Structure Preset Value How to reset the status data Program example using the status byte STB How to enable status reporting ’Defines SRQ-routine Error-reporting routine How to report errors ’Sends error query How to restore initial settings Saving/Restoring Instrument SetupsHow to save/restore a setup via instrument memory How to save/restore a setup via the Gpib controller Front Panel Simulation How to simulate the pressing of a front panel keyRow 201 Row 801 Autoset Simulation How to simulate the operation of a softkey menu Envelope Functions not Directly ProgrammableDISPlayMENU ACQuireSYSTemKEY 3 toggles on/off MULTiple-shot Meta symbols Syntax specification notationsNon-terminal symbols Terminal symbols Not contain the message element DefaultBetween the square brackets, without MEASureVOLTageDC? is the same An explicit decimal point and may or may not be Data typesPreceded by a sign, e.g Double quotes Bit codesExamples This is a string ’This also’ Command Summary Gate Feed Menu Name Command Reference ParametersState DATA? Read Auto TYPE? RTS DTRBaud Bits Type PAL Secam Ntsc Hdtv ALL Timeresolution Expectedvoltage ,resolutionMeasurefunction Measureparameters Referencelow ,referencehigh,expectedtime Command Descriptions Front panel compliance ErrorsSpecifies the compliance with front panel operations Syntax *CAL? Response 0 CAL? CALibrationCalibration okay Calibration not okay Limitation Clear Status 16COMMAND Reference Byte Register. Alternative commands *ESE #B10001 Event Status EnableAtion Complete bits to be summarized in the Status *ESE #H11 Event Status Register 18COMMAND ReferenceResponse Integer Description PON URQ CME EXE DDE QYE RQC OPC ESR Syntax *IDN? IDN? Identification Operation Complete 20COMMAND ReferenceQuery form *OPC? Response Description Restrictions Ieee EXT EM MP OPT? Option identification 22COMMAND Reference Recall instrument setupSyntax RCL numericdata Description Function Default Settings RST ResetSyntax *RST Description Measure 1 Beeper Hardcopy Print & Plot Plotter Hpgl Pass/Fail testingMath 1 Cursors Syntax SAV numericdata Description Save instrument setup 26COMMAND Reference Service Request EnableRequest Enable Register Syntax STB? Response Integer Description STB? Status Byte Syntax *TRG Description TRG Trigger Syntax *TST? Response 0 TST? Self-testSelf-test okay Self-test not okay Command Reference ABORt Configures for AC-RMS valueSyntax ABORt Description Aborts the current acquisition CALCulatenDERivativePOINts CALCulatenDERivativeSTATe Switches the differentiateFunction on CALCulatenFEED Filter function turned off Filter function turned on Integrate function turned off Integrate function turned on CALCulatenINTegralSTATe CALCulatenMATHEXPRession Switches MATH2 function on CALCulatenMATHSTATe Switches MATH1 function on Response ABS REL Query form CALCulatenTRANsformFREQuencyTYPE? Selects relative MATH2-FFT calculation Switches MATH2-FFT onSelects MATH2-FFT-HANNing window CALCulatenTRANsformHISTogramSTATe SwitchesHistogram function turned off Histogram function turned on Syntax CALibrationALL Query form CALibrationALL? CALibrationALLResponse 0 Description Reads condition register Starts auto calibrationConditions Syntax CONFigureVOLTagemeasurefunction CONFigureSyntax elements are specified with the MEASure? query Expected voltage 600 mV Signal on channelChannel 2 AC coupled Initiates + fetches AC-RMS Query form DISPlayBRIGhtness? MINimum MAXimum DISPlayBRIGhtnessResponse NR3 NR30.00E00 .. .00E00 DISPlayMENUNAME DISPlayMENUSTATe Switches TB Mode menu display onDisplay turned off Display turned on DISPlayWINDow1TEXTnDATA? Type Analog Mode Digital ModeSyntax DISPlayWINDow1TEXTnDATA? Response is peak-peak value of 608.4 mV MEAS1 Display on Clears all user text DISPlayWINDow2TEXT1CLEar As text DISPlayWINDow2TEXT1DATASends 25 decimal Character byte Command Reference DISPlayWINDow2TEXT1STATe FETCh? 54COMMAND ReferenceFETChVOLTagemeasurefunction? Voltageparameters, measureparameters Restrictions Acquisition INT,8 FORMatDATA HCOPyDATA? HCOPyDEVice Response 1 INITiateCONTinuous Syntax INITiateIMMediate INITiateIMMediateTrigger level becomes Single shot acquisition INPutnCOUPling Response 2.00E+07 INPutnFILTerLPASsSTATe INPutnFILTerLPASsFREQuency?Query form INPutnFILTerLPASsSTATe? Common low pass filter off Common low pass filter on INPutnIMPedance After a *RST command, the impedance is 1 MΩSyntax INPutnIMPedance NRf MINimum MAXimum 1E6 Response Norm INV Description INPutnPOLarity Response DIG Anal INSTrumentNSELect INSTrumentSELectDIG Anal Channellist = MEASure?Measurefunction measureparameters High Falltime First falling edge equals the REFerence MIDDle until Signal. The peak to peak value is the difference betweenPDUTycycle Referencemiddle Ratio percentage of the positive width PWIDth Measureparameters Risetime Frequencyresolution = NRf DEFault Executed. The unit of timeresolution is secondReferencemiddle is volt Expectedperiod = NRf DEFault Periodresolution = NRf DEFault Limitations Description Syntax READVOLTagemeasurefunction? 74COMMAND Reference Example SENSeAVERageSTATe Syntax SENSeAVERageCOUNt NRf 8 16 SENSeAVERageTYPE? SENSeAVERageCOUNt SENSeAVERageTYPE?Response Scal Initiates trace averaging Addition of channel i+j is off Addition of channel i+j is on SENSeFUNCtionOFF SENSeFUNCtionON SENSeFUNCtionSTATe? Limitations SENSeSWEepOFFSetTIME SENSeSWEepPDETectionSTATe SENSeSWEepREALtimeSTATe Real-time mode switched off Real-time mode switched onSlope = either pos. or neg Reads AC-RMS SENSeSWEepTIME MTB values in the digital modeQuery form SENSeSWEepTIME? MINimum MAXimum Base range is limited to 10 μs non-alternating time base Requests sweep time Coupled valuesReads sweep time Requests nr of trace points SENSeSWEepTIMEAUTO Autoranging MTB switched off Autoranging MTB switched onSets trigger source CH1 Sets autoranging MTB on Switches CH2 on Switches CH1 onSENSeVOLTagenDCRANGeAUTO Autoranging CH2 Channel SENSeVOLTagenDCRANGeOFFSet Query form SENSeVOLTagenDCRANGePTPeak? MINimum MAXimum SENSeVOLTagenDCRANGePTPeak Sensitivity = 0.8 / 8 = Peak-to-peak =100 mV/div Trigger source = Response NR1 Description BIT Decimal Meaning Number Value Syntax STATusPRESet STATusPRESetFollowing table defines the effect of STATusPRESet Status Register Filter / Enable Preset Value Response NR1 Description Returned value 16 equals bit 4 set temperature too high/low TEMPerature too high or too lowEnables report of TEMPerature too high/low 0 Enables report of TEMPerature within allowed limits 1 Error number is -222 and the meaning is Data out of range No errorSTATusQUEueNEXT? 350,Queue overflow Reads the error queue Beeper disabled Beeper enabledBeeps on error SYSTemBEEPer SYSTemBEEPerSTATe Response on Stan Wire controlStan None XONEven ODD None Response 7 No X-on/X-off handshaking Response XON None1200 Becomes Sets the system date to Nov 7 SYSTemDATE SYSTemERRor? Response NR1 SYSTemKEY Front Panel KEY Returns the last key simulation Enables Utility softkey menu SYSTemSET Nodenr nodelength firstbyte ... lastbyte SYSTemTIME SYSTemVERSion? *RST command doesn’t change the current Scpi versionSyntax SYSTemVERSion? Response YYYY.V TRACeCOPY Response definiteblock TRACeDATA Initiates single acquisition Reads channel 1 trace Requests channel 1 traceQueries peak-to-peak Reads peak-to-peak TRACePOINts Requests M23 trace Number of trace points for allReads M23 trace Sets high-pass filter off Pass BooleanSets high-pass filter on Low-pass filter active High-pass filter active HF-reject Filter Frequency LOW-PASS on HIGH-PASS on Automatically switchesDC coupling HF-reject AC coupling KHz LF-reject Low-Pass filter off TRIGgerSEQuence1FILTerLPASsSTATe Boolean TRIGgerSEQuence1FILTerLPASsFREQuency NRfTRIGgerSTARtFILTerLPASsFREQuency NRf TRIGgerSTARtFILTerLPASsSTATe Boolean Frequency LOW-PASS on HIGH-PASS on FilterSets cutoff frequency = 30 KHz TRIGgerSEQuence1HOLDoff TRIGgerSTARtHOLDoff TRIGgerSEQuence1LEVelAUTO Boolean TRIGgerSEQuence1LEVel NRf MINimum MAXimumTRIGgerSTARtLEVel NRf MINimum MAXimum TRIGgerSTARtLEVelAUTO Boolean Channel Continuous initiation Trigger source BecomesDiv. sensitivity Trigger level becomes 0.2 TRIGgerSEQuence1SLOPe TRIGgerSTARtSLOPe After a *RST command, the trigger slope is POSitivePOS NEG Sets real-time mode on Configures AC-RMS CH2Triggering is done at positive Rising and negative falling IMM TRIGgerSEQuence1SOURce TRIGgerSTARtSOURceEXT Input channel 1 becomes Configures AC-RMS CH1Trigger source Single initiation Edge TRIGgerSEQuence1TYPE TRIGgerSTARtTYPESelects edge triggering Numb Selects lines triggering Selects TV video Linenr = linenr + 625/2 linenr = linenr 625/2Selects video lines Selects video line Scam Secam Secam Ntsc Hdtv Scam Lines/frame Selects SelectsLines/frame Selects Secam Lines/frame Selects Hdtv Response POS NEG Positive video signal polarity selected PAL or Secam From 1 to 123 Selects Negative Video Signal polarity Error reporting is invoked as follows Call errorcheck Making a Hardcopy of the Screen Pass/Fail TestingApplication Program Examples Application summary Making automatic measurementsFETChNWIDth? Application program ’Termination Receive on EOI Making programmed measurements Reading measurement values Acquiring Waveform Traces Save/recall settings to/from internal memory Saving/Recalling Instrument Setups Application summary Application program CombiScope Instrument Making a Hardcopy of the ScreenIeee Saving a pass/fail test setup Pass/Fail Testing Application program Restoring a pass/fail test setup DISPlayMENU MEASure Running a pass/fail test Cross References Cross Reference Front Panel Keys / CommandsChannel 4 is external trigger input for PM33x0B Page Acquire menu Cross Reference Softkey Menus / Commands Cursors menu Programmable with the *SAV/*RCL and Systset commands Ext instead of ch4 for PM33x0B Display menu Other functions with RCL/SAV and Systset Mathplus Math menu Yes no Page DTB DEL’D TB menu Measure menu SAVE/RECALL menu Setups menu Systset RCL/SAV TB Mode menu Trigger menu Analog Mode Logic Utility menu Wire Ieee Inpfilt Onoff INP1IMP INP2IMP INP3IMP INP4IMP Vertical menu Cross Reference Functions / Commands Average Function + KEYS/MENUS Related Scpi Commands AutosetBW Limit Calibration Autocal Delay Measurement DelayDelayed Timebase DEL’D TB Differentiate Mathplus Histogram Mathplus FFT ON/OFFHold OFF CH1 Logic Trigger Integrate MathplusMagnify Horizontal Main Time Base Pass Fail Testing Mathplus SAV, *RCL Function + KEYS/MENUS Related Scpi Commands MathematicsPower Supply Measure Menu Remote Setup Remote Control IEEE-488.2Remote Control RS-232 Probe Utilities Status Screen Function + KEYS/MENUS Related Scpi CommandsSubtract Mathematics Text OFF Single TrigMulti Roll Trigger DEL’D TB Trigger CouplingTrigger Level Trigger Main TB Util Menu User TextUtil Screen & Sound DISPlayWINDow1TEXT12DATA? Abbreviations Used IDN IDYIEC IFC REN Manual Conventions RAMRQC RQS List of Tables Glossary of Symbols Used4MANUAL Conventions List of Figures Documents Referenced Scpi Conformance Information TRIGgerSEQuence1 STARtVIDeoFORMatTYPE type command PurposeStandards Information Or abbreviation, e.g., type = Hdtv List of Implemented IEEE-488.2 Syntactical Elements Standards Information Program Message Unit Separator Command Program HeaderProgram Data Separator Program Header Separator Channel 1/2/3/4 settings End node settingsProbe scale settings Common vertical settings Event trigger delay settings Delayed timebase settingsCursor settings Cursor autosearch settings Display settings MATH1/2 settingsTrace intensity settings Display trace position settings Index Numerics Index Index Index Index Index Index Index Index Index Index Index