Agilent Technologies 8590, 90235 FFT Fast Fourier Transform

FFT

Fast Fourier Transform

Performs a discrete fast Fourier transform on the source trace array and stores the result in the

destination array.

Syntax

FFT

-

destination

user-defined trace

,-

window

-\

user-defined trace user-defined trace

Item

I

Description/Default

User-defined trace A trace defined by the TRDEF command.

I

Range

Any valid trace name.

Prerequisite Commands: TWNDOW.

Related Commands: MKREAD, TWNDOW.

Restrictions: Not available with Analog+ display mode. See “ANLGPLUS” for more

information.

Example

OUTPUT

718."IP*SNGLS*"

OUTPUT

718;"CFy300MHk;TS;MKPK

HI;MKTRACK ON;"

OUTPUT

718;"CONTS;SP

200KHZ;RB

IOOKHZ;"

OUTPUT

718;"MKTRACK

0FF;SP

OHZ;"

OUTPUT

718;"MKPK

HI;MKRL;LN;SNGLS;"

OUTPUT

718;"ST

800MS;TS;"

OUTPUT

718;"TWNDOW

TRB,FLATTOP;"

Initializes spectrum

anulyxer:

Tunes center frequency to the car-

rier and

decreoxes

span.

Changes resolution bandwidth to cap-

ture modulation.

Reduces span to zero Hz to demodu-

late carrier

Changes to linear amplitude

scale,

Sets sweep time to correspond to

modulation

frequ&ncy,

the executes

FFT function.

The TWNDOW must be

defiined

be-

fore using the

F~jknction.

5-160

Programming Commands

Contents

Main Programmers Did Guide Page Certification Regulatory Information Warranty Assistance Safety Notes Warning Caution General Safety Considerations How to Use This Guide This guide uses the following conventions: HP 8590 D-Series and E-Series Spectrum Analyzer Documentation Description HP 8591C Cable TV Analyzer Documentation Description Contents Page Page Page Page Page Page Page Page Figures Xhbles Preparing for Use Connecting Your Spectrum Analyzer to a Computer Configuring Your Computer System Page Page Test Program HP-IB Connections for the HP 9000 Series 300 Technical Computers Page HP-IB Connections for the HP Vectra Personal Computer Page RS-232 Connections for the HP Vectra or IBM PC/AT Personal Computer Page Printing or Plotting Printing Using an HP-IB Interface Note Page Plotting Using an HP-IB Interface Page Printing Using an RS-232 Interface Note Page Plotting Using an RS-232 Interface Note Printing after Plotting or Plotting after Printing Printing Using a Parallel Interface Page Plotting to an HP LaserJet Printer Printing after Plotting or Plotting after Printing If There Is a Problem Writing a Program Note Writing Your First Program Composing the. Program Note Modifying the Program Page Enhancing the Program with Variables Page Getting Information from the Spectrum Analyzer Page Programming Guidelines Programming Xbpics Controlling Trace Data with a Computer Reading Trace Data Page Saving Trace Data Page Reading Trace Data from a Computer Disk Saving and Recalling Instrument States Saving the Spectrum Analyzers State Page Note Page Page Returning the Spectrum Analyzer to its Former State Page Page Measuring Harmonic Distortion Page Page Page Page Different Formats for Trace Data Transfers P Format Page Page Page Page Page M Format - 7 Y 4 Note Page Creating and Using Downloadable Programs What is a DLP? Why Use a DLP? Creating a DLP lb User-Defined Use a Function within a DLP Use a User-Defined Variable within a DLP Use a User-Defined Trace within a Enter Values into a DLP To Enter Values into a by Using a Softkey Create a Modular 4-8 Creating and Using Downloadable Programs Executing a DLP Execute a by Using a Softkey lb Execute the DLP within a Program Storing DLPs DLFs Store on a RAM Card Load DLPs from a Memory Card into Analyzer Memory Determining the Amount of Memory Needed for a DLP Determine Available Analyzer Memory Determine the Amount of Space on a RAM Card Example 4-13 is 75 (128 card RAM 53), 1 = lb Delete a from Spectrum Analyzer Memory lb Erase the DLP from a RAM Card Using the DLP Editor Connect the External Keyboard to the Spectrum Analyzer Ib Access the DLP Editor t9 Create a DLP Modify the lb Modify a Catalog Item DLP Programming Guidelines Make the More Readable Find Problems in a DLP Page Programming Commands Syntax Conventions Syntax Elements are shown in the syntax diagrams as elements within rectangles. 5-1. Syntax Elements 5-3 Programming Commands 5-1. Syntax Elements (continued) 5-4 Programming Commands lhble Programming Commands 5-5 5-2. Characters and Secondary Keywords (Reserved Words) EQ 5-5 Programming Commands Ikble 5-2. Programming Commands 5-7 5-8 Programming Commands 8568A/B, Programming Commands 5-9 able HP 8566A/B, 5-3. Summary of Compatible Commands (continued) 5-4. Functional Index AUTO 5-12 Programming Commands Programming Commands 5-13 5-14 Programming Commands Programming Commands 5-15 5-4. Functional Index (continued) RQS SRQ 5-l 5 Programming Commands 5-17 STEP 5-18 Programming Commands t4hRKER BUT0 Page 5-20 Programming Commands lfdble 5-4. Functional Index (continued) Programming Commands 5-21 5-22 Programming Commands Programming Commands 5-23 5.24 Programming Commands ltdble 5-4. Functional Index (continued) Programming Commands 5-25 AUTO 5-26 Programming Commands 0ble 5-4. Functional Index (continued) 5-27 l 5.28 Programming Commands ABORT Abort Page ABS Absolute ABS Absolute 5-31 Places the absolute value of the source values in the destination. J Programming Commands Page ACP Adjacent Channel Power ACP Adjacent Channel Power ACP Measurement Results Executing ACP exits the following functions: windows display mode 5.34 Programming Commands Restrictions (TOI), dB ACPBW Channel Bandwidth Page ACPCONTM Continuous Sweep Measurement ACPE Adjacent Channel Power Extended ACPE Adjacent Channel Power Extended 10. If no error occurred, query trace A (TRA) for the trace results of the ACPE measurement. Programming Commands 5-39 POWCT (TOI), dB ACPGR Adjacent Channel Power Graph On or Off Page ACPGRAPH Compute the Adjacent Channel Power Graph ACPMK Adjacent Channel Power Marker On or Off ACPPAR ACP Manual or Auto Page ACPSNGLM Single Sweep Measurement ACPSP Channel Spacing ACPSP Channel Spacing ACTDEF Active Function Definition ACTDEF Active Function Definition Programming Commands 5-49 ACTDEF Creates a user-defined active function. Page Page Page Page ACTVF Active Function ADD Add ADD Add 5.55 ADDADD Prerequisite Commands: TRDEF when using user-defined trace. ACTDEF or VARDEF Adds the sources and sends the sum to the destination. Page AMB Trace A Minus Trace B Page Page AMBPL Trace A Minus Trace B Plus Display Line Page AMPCOR Amplitude Correction Page AMPLEN Amplitude Correction Length ANLGPLUS Analog Plus ANLGPLUS Analog Plus ANNOT Annotation APB Trace A Plus Trace B AT Attenuation Page AUNITS Amplitude Units AUTO Auto Couple AVG Average AVG Average Programming Commands 5-73 Averages the source and the destination. Related Commands: CLRAVG, TS. Page AXB Exchange Trace A and Trace B BAUDRATE Baud Rate of Spectrum Analyzer Page BIT Bit Page BITF Bit Flag n Programming Commands 1 ( Page BLANK Blank Trace BML Trace B Minus Display Line BTC Transfer Trace B to Trace C BXC Trace B Exchange Trace C CAL Calibration Page Page CAT Catalog Cataloging the Memory Card Cataloging Spectrum Analyzer Memory Page CF Center Frequency c Page CHP Channel Power Page CHPGR Channel Power Graph On or Off CLRAVG Clear Average CLRBOX Clear Box Jl.Jl CLRBOX Clear Box to 200,200. 1,l rectangular area of Page CLRDSP Clear Display CLRW Clear Write CLS Clear Status Byte CMDERRQ Command Error Query CNF Confidence I&t CNTLA Auxiliary Interface Control Line A CNTLB Auxiliary Interface Control Line B CNTLC Auxiliary Interface Control Line C CNTLD Auxiliary Interface Control Line D CNTLI Auxiliary Interface Control Line Input COMB Comb COMPRESS Compress Trace Prerequisite Commands: TRDEF when using user-defined trace. TS when using trace data. Page CONCAT Concatenate Combines two traces. Programming Commands J Related Commands: MOV, VIEW. Page CONTS Continuous Sweep CORREK Correction Factors On COUPLE Couple CRTHPOS Horizontal Position of CRT Display CRTVPOS Vertical Position of CRT Display CTA Convert to Absolute Units Page CTM Convert to Measurement Units DA Display Address Page Page DATEMODE Date Mode DEMOD Demodulation DET Detection Mode Page DISPOSE Dispose Page DIV Divide DIV Divide Programming Commands 5-133 Divides source 1 by source 2 and places the result in the destination. Related Commands: MPY, SNGLS, TS. Page DL Display Line Page DN Down DONE Done Page DOTDENS Dot Density DRAWBOX Draw Box Page DSPIX Display 5-143 DSPLY Display Displays the value of a variable on the spectrum analyzer screen. Related Commands: DA, PA, PD, PR, PU. Programming Commands Page DT Define Terminator EE Enable Entry Page EK Enable Knob ENTER Enter From HP-IB Note Page EP Enter Parameter Function Note ERASE Erase EXP Exponent EXP Exponent Related Commands: FUNCDEF, LOG. Page Page FA Start Frequency Page FB Stop Frequency Page FFT Fast Fourier Transform Page Page FFT Fbst Fourier Transform Figure 5-5. Uniform Filter Window Programming Commands 5-163 Figure 5-6. Flat Top FFTAUTO Marker to Auto FFT Page FFTCLIP FFT Signal Clipped FFTCONTS FFT Continuous Sweep FFTMKR FFT Markers FFTMM FFT Marker to Midscreen FFTMS FFT Marker to FFT Stop Frequency FFTOFF FFTOff FFTPCTAM FFT Percent Amplitude Modulation Off I-- 7 I= FFTPCTAMR FFT Percent Amplitude Modulation Readout FFTSNGLS FFT Single Sweep Page FFTSTAT FFT Status FFTSTOP FFT Stop Frequency Page FMGAIN FM Gain -...._.: T--*0-+ FOFFSET Frequency Offset . ..._.. Page FORMAT Format Card FS Full Span FUNCDEF Define Function 5-184 Programming Commands Page GATE Gate GATECTL Gate Control GC Gate Preset GD Gate Delay GDRVCLPAR Clear Pulse Parameters GDRVGDEL Gate Delay for the Frequency Window Page GDRVGLEN Gate Length for the Frequency and Time Windows GDRVGT Window Gate Control Page GDRVGTIM Gate Trigger to Marker Position for the Time Window I ! Page GDRVPRI Pulse Repetition Interval GDRVPRI Pulse Repetition Interval GDRVPRI returns the current value for the pulse repetition interval. GDRVPWID Pulse Width GDRVPWID Pulse Width GDRVPWID returns the current value for the pulse width. GDRVRBW Couple Resolution Bandwidth to Pulse Width Page GDRVREFE Enter Reference Edge II GDRVREFE Enter Reference Edge GDRVST Couple Sweep Time to Pulse Repetition Interval Page GDRVSWAP Update the Time or Frequency Window GDRVSWDE Delay Sweep for Time Window Page GDRVSWP Sweep Time for the Time Window Page GDRVUTIL Gate Utility Page GDRVVBW Couple Video Bandwidth to Gate Length Page GETPLOT Get Plot Or, Note GETPRNT Get Print -a--+ Page ( GP Gate Polarity GR Graph c GRAT Graticule HAVE Have QPD I HD Hold Data Entry ( HN Harmonic Number HNLOCK Harmonic Number Lock T BAND LOCK ON (HNLOCK ON) Start Frequency Stop Frequency Center Frequency Span BAND LOCK OFF (HNLOCK OFF) Page HNUNLK Unlock Harmonic Number IB Input B ID Identify IF THEN ELSE ENDIF If Then Else 5-236 Programming Commands IF/THEN/ELSE/ENDIF The Page Page INT Integer INT Integer Programming Commands 5-239 Places the greatest integer that is less than or equal to the source value into the destination. 4 Related Commands: REPEAT/UNTIL. Page INZ Input Impedance IP Instrument Preset Page Page Page KEYCLR Key Clear KEYCMD Key Command KEYCMD Key Command Programming Commands 5-247 softkey. Allows you define the function and label of a The softkey label is updated whenever a softkey is pressed. Page Page Page KEYDEF User-Defined Key Definition I 5-251 KEYDEF User-Defined Key Definition II, Page Page Page KEYENH Key Enhance KEYENH Key Enhance Programming Commands 5-255 KEYENH Allows you to activate inverse video mode or underline part or all of the softkey label. XKEYENH Page Page Example 4 Using Enhancements Page KEYEXC Key Execute KEYLBL Key Label Page LB Label Page 1 . LB Label 1 5-266 Programming Commands ible 5-7. Label Functions LF Base Band Instrument Preset LG Logarithmic Scale LIMIDEL Delete Limit-Line Table LIMIDISP Limit Line Display Page LIMIFAIL Limits Failed Page LIMIFT Select Frequency or Time Limit Line LIMIHI Upper Limit LIMILINE Limit Lines Page LIMILINE Limit Lines Programming Commands 5-278 LIMILO Lower Limit LIMIMIRROR Mirror Limit Line ! f LIMIMODE Limit-Line Entry Mode Page LIMIREL Relative Limit Lines Page LIMISEG Enter Limit-Line Segment for Frequency LIMISEG Enter Limit-Line Segment for Frequency Programming Commands 5-285 Item Description/Default -0 Range Number Any real or integer number. Default unit is dBm. Varies with FOFFSET and ROFFSET. Related Commands: LIMIDEL, LIMILINE, LIMIMODE, LIMIREL, SEGDEL, SENTER. Page Page LIMISEGT Enter Limit-Line Segment for Sweep Time p--J Programming Commands .., I Related Commands: LIMIDEL, LIMIFT, LIMILINE, LIMIMODE, LIMIREL, SEGDEL, SENTERT. Page Page LIMITEST Enable Limit Line &sting Page LINFILL Line Fill LINFILL Line Fill 5-283 Fills linear interpolated data into the specified trace data points of a destination trace. J Programming Commands Page LN Linear Scale LOAD Load Page LOG Logarithm E&es 5-298 Programming Commands M Page Page Page MDS Measurement Data Size c Query Response: MDU Measurement Data Units Page MEAN Trace Mean MEANTH Trace Mean Above Threshold Page MEASOFF Measurement Off MEASURE Measure Mode Page MEM Memory Available MENU Menu Page MERGE Merge Two Traces MERGE Merge Two Traces 15 Merges the source trace into the specified area of the destination trace. R=v3e Related Commands: All other trace math commands. See lkble 5-4 for a list of trace math commands. Page MF Marker Frequency Output Page MIN Minimum MIN Minimum 5-319 Compares source 1 and 2, point by point, and stores the lesser of the two in the destination. Related Commands: MINPOS, MXM, TS. Programming Commands Page MINH Minimum Hold MINPOS Minimum Position MIRROR Mirror Image Page MKA Marker Amplitude Page MKACT Activate Marker Note MKACTV Marker As the Active Function MKBW Marker Bandwidth MKCF Marker to Center Frequency MKCONT Marker Continue MKD Marker Delta Page MKDLMODE Marker Delta Display Line Mode Page MKF Marker Frequency I Page MKFC Marker Counter MKFCR Marker Counter Resolution .....-.: Page MKMIN Marker Minimum MKN Marker Normal Page MKNOISE Marker Noise Page MKOFF Marker Off MKP Marker Position Page MKPAUSE Marker Pause Page MKPK Marker Peak MKPX Marker Peak Excursion Page MKREAD Marker Readout =Q MKRRAD Marker Readout 5-355 FRQ Programming Commands MKRL Marker to Reference Level MKSP Marker to Span MKSS Marker to Step Size MKSTOP Marker Stop MKTBL Marker Ihble Page MKTRACE Marker Trace MKTRACK Marker Track MKTYPE Marker Type ML Mixer Level MOD Modulo MOD Modulo Programming Commands 5-367 Stores the remainder from the division of source 1 by source 2 in the destination. Related Commands: DIV. Page MODE Mode MOV Move Copies the source values into the destination. Programming Commands Range using a user-defined variable. Page MPY Multiply Multiplies the sources, point by point, and places the results in the destination. Programming Commands R-m 5-372 Page MS1 Mass Storage Is MXM Maximum MXM M2lXhU.In 5-375 ----- Related Commands: MIN, PKPOS, TS. Programming Commands Page MXMH Maximum Hold M4 Marker Zoom Page NDB Number of NDBPNT N Points Syntax Example Page NDBPNTR N Points Bandwidth Query Response NRL Normalized Reference Level Page OA Output Active Function Value OBW Occupied Bandwidth Page OBWPCT Occupied Bandwidth Percent OL Output Learn String ONCYCLE On Cycle Page ONDELAY On Delay Query Response ONEOS On End of Sweep I kt ONMKR On Marker Page ONMKRU On Marker Update Page ONPWRUP On Power Up ONSRQ On Service Request Page ONSWP On Sweep +( #A Page Page OP Output Parameter C OUTPUT Output to Remote Port or Parallel Port OUTPUT Output to Remote Port or Parallel Port 5.408 Allows the spectrum analyzer to send data to other devices via remote or parallel ports. f Programming Commands Page Page PA Plot Absolute I PARSTAT Parallel Status Reports the status of the printer connected to the parallel port. (Option 024, 041, 043). Programming Commands OUTPUT 718; PARSTAT; Related Commands: PRINT, PARSTAT Parallel Status 5-415 5-9. Spectrum Analyzer Status Byte (Option 041, 043) Programming Commands PCTAM Percent AM Page PCTAMR Percent AM Response PD Pen Down PDA Probability Distribution of Amplitude Programming Commands Related Commands: PDF, RMS, STDEV. 5-420 Page PDF Probability Distribution of Frequency Page PEAKS Peaks Page PEAKS Peaks L 5-426 Programming Commands 47 . . . . . . . . . . . . . . . . . . . . . . . . . .0 Page PKDLMODE Peak Table Delta Display Line Mode Page PKPOS Peak Position PKRES Peak Result Page PKSORT Peak Sort PKTBL Peak Ihble Page PKZMOK Peak Zoom Okay PKZOOM Peak Zoom .._... -G--+ Page PLOT Plot Page PLTPRT Plot Port POWERON Power-On State Note PP Preselector Peak PR Plot Relative PREAMPG External Preamplifier Gain Note PREFX Prefix Page Page PRNTADRS Print Address PRNPRT Print Port PSTATE Protect State PU Pen Up PURGE Purge. File PWRBW Power Bandwidth Page PWRUPTIME Power Up Time RB Resolution Bandwidth Page RCLS Recall State RCLT Recall Trace Page RELHPIB Release HP-IB REPEAT UNTIL Repeat Until REPEAT UNTIL Repeat Until Programming Commands 5-463 The REPEAT and UNTIL commands form a looping construct. (IF/THEN/ELSE/ENDIF). Page Page RETURN Return REV Revision RL Reference Level Page RLPOS Reference-Level Position RMS Root Mean Square Value ROFFSET Reference Level Offset RQS Service Request Mask Page SAVEMENU Save Menu SAVES Save State SAVET Save Trace Page SAVRCLF Save or Recall Flag SAVRCLN Save or Recall Number Page SAVRCLW Save or Recall Data SEGDEL Segment Delete Page SENTER Segment Entry for Frequency Limit Lines Note Page SENTERT Segment Entry for Sweep Time Limit Lines 5488 Programming Commands SENTERT -I us / Page Page SER Serial Number SETDATE Set Date SETTIME Set Time SMOOTH Smooth Trace Smoothes the trace according to the number of points specified for the running average. 5494 Programming Commands Related Commands: SNGLS, TS, VAVG. Page SNGLS Single Sweep SP Span Page SPEAKER Speaker SPZOOM Span Zoom SQLCH Squelch SQR ! Programming Commands Square Root Places the square root of the source into the destination. Page SRCALC Source Leveling Control Page SRCAT Source Attenuator Page SRCNORM Source Normalization Page SRCPOFS Source Power Offset SRCPSTP Source Power-Level Step Size Page SRCPSWP Source Power Sweep Page SRCPWR Source Power Page SRCTK Source Tracking Page SRCTKPK Source Tracking Peak SRQ Force Service Request Note Page Interface Differences Polled Mode of Operation Status Byte Definition Page ss Center Frequency Step Size Page ST Sweep Time Page STB Status Byte Query STDEV Standard Deviation of Trace Amplitudes Page STOR Store STOR Store Programming Commands 5-531 Stores data on a RAM card. Page Specifying the source SUB Subtract Subtracts source 2 from source 1, point by point, and sends the difference to the destination. Programming Commands Related Commands: AMB, AMBPL, BML, LIMITEST, SUM. 5-534 Page SUM Sum of Trace Amplitudes SUMSQR Sum of Squared Trace Amplitudes SWPCPL Sweep Couple Page SYNCMODE Synchronize Mode Page TA Transfer A TB Transfer B TDF Trace Data Format TDF P TDF A TDF I TDFI Page Page TEXT lkxt TH Threshold TIMEDATE Time Date TIMEDSP Time Display TITLE Title TM Trigger Mode Note Page TO1 Third-Order Intermodulation Measurement Page TOIR Third-Order Intermodulation Response TRA/TRB/TRC Trace Data Input and Output Page TRCMEM Trace Memory TRDEF Trace Define Creates a user-defined trace. Programming Commands LIefines NEW,lOO;" Page TRDSP Trace Display TRGRPH Trace Graph Page TRMATH Trace Math TRMATH Trace Math 5.567 Executes a list of spectrum analyzer commands at the end of each sweep. ONEOS, ONMKR, ONSRQ, ONSWP, ONDELAY, < #A TRPRST Trace Preset TRSTAT Trace Status TS Thke Sweep TVLINE TV Line TVSFRM TV Frame Page TVSTND TV Standard Page TVSYNC TV Sync TWNDOW Trace Window up UP UP Page Page VARDEF Variable Definition Creates a user-defined variable and assigns it a value. Programming Commands Related Commands: DISPOSE, TRDEF. 5.582 Page VARIANCE Variance of Trace Amplitudes Page VAVG Video Average VB Video Bandwidth Page VBR Video Bandwidth Ratio VIEW View Trace WAIT Wait WINNEXT Window Next WINOFF Window Off WINON Window ON WINON Window ON Programming Commands 5-595 5-11. Programming Commands That Exit The Windows Display Mode WINOFF to turn the windows off. WINZOOM Window Zoom XCH Exchange XCH Exchange 5-597 Exchanges the contents of sources 1 and 2. Related Commands: AXB, BXC. Programming Commands Page ZMKCNTR Zone Marker at Center Frequency ZMKCNTR Zone Marker at Center Frequency ZMKPKNL Zone Marker for Next Left Peak ZMKPKNR Zone Marker for Next Right Peak ZMKSPAN Zone Marker Span Page Spectrum Analyzer Error Messages Error Messages Page Page Page Page Page uJ> Page Page Page B HP-IB and Parallel Option 041 0 PARALLEL 0 C RS-232 and Parallel Option 043 10. lo What Youll Learn in This Appendix Baud Rate Note Protocol Figure C-2. HP 245426 25-pin to g-pin Full Handshaking Connection Figure C-3. HP 24542U g-pin to g-pin Full Handshaking Connection C-3 Figure C-4. 25-pin Connecting a ThinkJet Printer I 1 DTR. Connecting a LaserJet Printer connect an HP LaserJet printer to the spectrum analyzer, use the information in Figure C-7. Connecting a Modem Connecting an HP-GL Plotter Switch Settings Setting the Spectrum Analyzer Baud Rate Note Index