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Agilent Technologies 71501D User's Manual

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1. select Setup TRA 9a ie Traces Iisa SCALE REF Measure LEY P0S fet i h T Ma AUTO arkers Mf W W LJ scate Masks persist 8 43755 ns 803 76 ps div Tri Chi ass gB m div TE Storage 244 mY ref Example Pattern M ode Display Add Time Delay Add time delay by pressing Setup DELAY Each push of the step keys U andf gives a change in delay equal to exactly one bit This technique can also be used to step the X offset of the mask one bit at a time to check for mask violations at each bit position Disconnect the RF cable from the pattern generator s TRIGGER OUT connector and connect the cable to the CLOCK OUT connector 8 Set channel 2 by pressing CH2 is CLK OUT Application Tutorials Tutorial 8 Display the Data Pattern Notice that the diagram softkey annotation no longer indicates pattern mode and a note is displayed on the screen as shown in the following figure Setup Trg Cal Traces allroad Mi Measure Markers Masks Trt C hi ass GB m div Storage 244 mY ref ial i annot display H RH if fe idj CLE QUT anita tolr a m y 9 43755 ns 803 76 ps div Example Display of User Error in Pattern Mode diagram EYELINE READ PAT GEN CHE is CLE OUT BIT INTUL DELAY eyef ltr
2. Setue ON OF extd BW Trg Cal ON OFF Traces Measure Markers r CODE Masks Bs 100 469 pa div VERSION Trt Cht Nass aB m div mare Storage 244 mY ref cof p User Corrections Applied to the Data Change to E yeline Mode 1 Set the analyzer to a known state by pressing INSTR PRESET Traces persist VARIABL and enter 5 diagram EYELINE Notice the level of the laser overshoot and the turn on delay varies from sweep to sweep dependent on the previous pattern of ones and zeros Application Tutorials Tutorial 5 Use Software Filters Setup INF INIT Trg Cal 2 WAR TABL Traces Measure Markers Masks OFF fs 100 465 psfdiv Trt Cht ass pA mW div prev Storage Ica mY ref menu Eyeline Display Showing Laser Overshoot Load the Software Filter Place the 70874A memory card in the front panel card slot Display the catalog of files on the memory card by pressing Mass Storage Turn the front panel knob to highlight the file a_bt 248832 Load the file into user corrections by pressing LOAD FILE This file simulates a 4th order Bessel Thomson filter with a cutoff at three quarters of the bit rate This allows you to observe the laser transmitter signal in a specified bandwidth This software filter is equivalent to using a hardware filter except that trace noise may be suppressed
3. Extinction Ratio BY 7 516 dB Measure ly eyel mean e 259 27 a 11 79 al THRSHLO P Level mean o 27 755 mi 0754 mi Eye Height 168 92 my 72 983 x LOWE Markers Crogsing Level 127 98 mY 43 091 THRSHLD Eye Width 291 84 ps 7252 Bit Interval 3 Eye Jitter 7 55 816 ps 1469 Bit Interva Masks Mean Rise Time 44 414 ps 10385 Bit Interval NUMBER Mean Fall Time 74 066 pa 1949 Bit Interval SAMPLES Nags Storage ea D faa T Example Extinction Ratio M easurement 10 Change the amount of data used for the histograms by pressing NUMBER SAMPLES and enter the of samples A larger value gives more accuracy but increases the data acquisition time When making extinction ratio measurements in eyeline mode the number of samples should be increased from the default of 1000 to something on the order of 20000 to insure a number of traces are evaluated to compute the extinction ratio 11 Clear the measured data from the screen by pressing OFF 2 7 Application Tutorials Tutorial 2 M easure in Optical Pow er Units Tutorial 2 Measure in Optical Power Units The analyzer display has the ability to show optical units referenced to the input of the optical to electrical converter This changes the channel and marker readouts to watts div 1 Set the analyzer to a known state by pressing INSTR PRESET Trg Cal CH1 EXT ATTEN responsivity value V Watt For example the foll
4. cJ trace PU AET ee eee ee ee eR T F Jdisplay Measure ON OFF j test Table f JONI OFF Tend on Analyze TOrF A 4count Calib t TRC DOT States fi fi 1 fi i Ja 1 ve Hz 1 GH Ad ty 1A GHz STSPes Tra Cht Li A page 1B dB div prev 2 af 2 1 dem ref Tr 2b menu A Limit Line Displayed on Screen Because you can perform repetitive testing of response shapes masks and limit lines are ideal for pass fail testing on production lines You create save recall and edit limit lines using the masks limits menu Access this menu using the left side Analyze softkey Since masks and limit lines are treated similarly in this chapter most refer ences to masks applies equally to limit lines Eye Diagram Analyzer Reference Masks and Limit Lines Testing Responses Once you ve created a mask or limit line set the following conditions for test ing e Trace to which testing is applied e Violations defined as traces or measurement points Testing ends after a set number of errors e Testing ends after a set number of traces Use the test ON OFF softkey to start testing Testing stops whenever one of the following events occurs A set number of trace sweeps A set number of violations e test ON OFF is set to OFF Numbers displayed at the bottom of the screen indicate the number of viola tions and trace sweeps that have occurred The following figure shows a response that has violated a limit line three tim
5. Set the bit interval and delay by pressing Setup BIT INTVL and enter 1 5 DELAY Adjust the delay to center the eye Select a mask by pressing Masks mask setup default masks STM 16 OC 48 The display shows an unscaled rectangle mask Align the mask by pressing MASK ALIGN Wait for the displayed samp count to reach 100 This step aligns the mask to the data using automatic scaling Notice that for the purposes of clarity the graticule is turned off This was done using the 70820A Config menu Application Tutorials Tutorial 6 Test to Industry Standards Setup setup Trg Cal ars Traces TES Measure ty is L Se t Marker err tre Masks Se 120 092 ps Gp pap pardiy l0 Hi a Tri Chi ass SB m div Le 7 Starage 16A mW ref L3 Tr 166 Error counts Number of traces counted Turn Mask Testing On Turn mask testing on by pressing Masks test ON OFF ON This resets the error counters Errors for the standard specifications show up beside the M1 screen annotation for mask violations and beside L2 and L3 for upper and lower limit violations respectively Notice that in this case violations are occurring due to too much overshoot Test with Additional Margin Set a 15 mask margin and turn margin testing on by pressing mask setup MASK MARGIN and enter 15 msk mar ON OFF ON This displays a second set of mask and limit lines for the 15 percent mar
6. 1 Enter aline of data by pressing MENU page 1 of 2 Calib user corr SELIEDT SEL New lines are added just above the highlighted line Use the front panel knob or arrow keys to highlight any field of the line which is to be below the new inserted line 2 Insert the line by pressing INSERT LINE To Edit a Line of Data To Deletea Line of Data To Select Flat Line Interpolation 1 N To Select Logarithmic Slope Interpolation Eye Diagram Analyzer Reference Agilent 70820A User Corrections To edit a line of data press MENU page 1 of 2 Cali b user corr SELIEDT EDT Use the front panel knob step keys or numeric keypad to change the dis played value If you are editing the path to next FREQ field change the value by pressing SLOPE FLAT Select the line of data to be deleted by pressing MENU page 1 of 2 Cali b user corr SELIEDT SEL Use the front panel knob or arrow keys to highlight any field in the line you wish to delete Delete the highlighted text by pressing other DELETE LINE Highlight the desired field by pressing MENU page 1 of 2 Calib user corr SELIEDT SEL Use the front panel knob or arrow keys to highlight the desired path to next FREQ field Select flat line interpolation by pressing SLOPE FLAT FLAT Select logarithmic slope interpolation by pressing MENU page 1 of 2 Calib user corr other slope LOG LIN LOG For logarithmic interpolation to take effect the path to
7. Eye Diagram Analyzer Reference Displaying Traces 1 green 2 cyan light blue 3 purple 4 rose 5 yellow This persistence works best with high values of N typically values of 50 through 100 In this mode no softkeys can be pressed until after EXIT GRAD ING is pressed Monochrome Grading Persistence Monochrome grading persistence MONO GRADING works just like color grading except that a given pixel increases in intensity instead of color each time a dot falls on it There are 15 different levels of intensity In this mode EXIT GRADING must be used to return to normal instrument operation a Apply persistence by pressing Traces persist PERSIST SWEEPS Enter one of the following e If variable persistence will be used enter the number of sweeps taken before a trace decrements in brightness e If grading persistence will be used enter the number of sweeps taken until the grading display is stopped b Press one of the four top right side softkeys to select the persistence mode c Pressing OFF can stop INFINIT and VARIABLE persistence at any time Eye Diagram Analyzer Referen Using Markers ce Using Markers Use this menu to activate the four available line markers X1 X2 Y1 and Y2 Markers allow you to measure or compare portions of the displayed waveform For example you can use markers to measure the peak to peak difference in a laser s turn on time as measured on the eye diagram s crossing point U
8. Getting Started Press MENU Config more 1 of 3 preview ON OFF ON For a demonstration of the Preview function press persist ON OFF Notice the corresponding programming command DISP PERS 1024 is displayed at the bottom of the screen Press MENU Config more 1 of 3 more 2 of 3 system ROM VERSION To View the Date and Time Eye Diagram Analyzer Reference Controlling the Display There are two clocks that can be displayed on the screen the display s clock and the 70820A module s clock You can control whether the clocks are dis played the indicated time and the display format When the mainframe is turned on the display sets the clock in the 70820A module This causes both clocks to indicate the same time Display HP 70820A clock clock RISE E 15 11 13 APR 15 1994 MENU Hal shan bi TIM DAT Trigger T 45 11 APR i5 1994 US EURO Traces t L SB Scale I Tack Markers g Config Hos 1B ns div page prey of E menu Control the 70820A s Clock 1 To control the 70820A s clock press MENU Config more 1 of 3 clock 2 To display the time or date press show TIM DAT TIM or show TIM DAT DAT The time and the date can be displayed simultaneously Eye Diagram Analyzer Reference Controlling the Display To select US or European display format press US EURO US or US EURO EURO To change the time or date press set clock Enter the new value in the same format as displayed
9. 2 7 extinction ratio measurement on low level signal with eye filtering 2 12 eye measurements 2 6 eyeline display showing laser overshoot 2 17 filtered laser overshoot 2 18 large overshoot resulting from laser bias 2 5 laser overshoot and turn on delay 2 14 limit line displayed on screen 3 10 pattern mode display 2 28 two masks displayed on screen 3 9 user corrections applied to the data 2 16 user created mask 2 23 extend the bandwidth to 40 GHz 3 17 EXTIN command 4 8 extinction ratio description 3 4 extinction ratio measurement 2 6 modes available 1 5 extinction ratios on low level signals 2 10 eye filtering 2 12 eye height description 3 4 eye jitter description 3 5 eye measurements example 2 6 eye mode 1 5 1 6 eye width description 3 5 eye diagram analysis 1 2 Index 2 eye diagram analyzer reference 3 2 eye diagram analyzer calibrating 3 23 eye diagram menus 3 12 eyeline software filters 1 9 eyeline mode 1 5 1 7 2 13 F fails program loading 1 17 fast amplitude and phase transitions 3 5 features of modes 1 5 fiber optics care of 1 iv e prefixes 3 40 es user correction 1 9 3 18 es Catalog 3 42 es change prefix 3 44 es custom prefix 3 45 es erase 3 43 es recall 3 43 ter from a transfer function 2 30 ter laser overshoot 2 18 ter software 2 17 ters software 2 15 irmware date code 3 20 flat line interpolation 3 55 forma
10. Each requires approximately 30 minutes to run For optimum performance you should per form the calibrations when at least one of the following is true e The temperature has changed 5 Centigrade since the last calibration was performed More than one week has passed since the last calibration Before any critical measurement Allow the microwave transition analyzer module to warm up for at least one hour before performing a calibration Eye Diagram Analyzer Reference Calibrating the Eye Diagram Analyzer 1 Connect a low loss cable between the front panel CALIBRATOR OUTPUT and channel 1 connectors Calibrator Output Coooojooo0o00 2 To calibrate the IF press MENU page 1 of 2 Calib IF calib CAL CH1 The calibration routine takes about 30 minutes to complete 3 Disconnect the cable from channel 1 and connect it to the channel 2 connector 4 Repeat the above procedure for channel 2 Eye Diagram Analyzer Reference Displaying Traces Displaying Traces Four Traces can be Displayed The Traces menu s select softkey allows you to display and control up to four traces The scaling reference positions and reference levels of each trace can be separately adjusted To automatically adjust the trace scale factor and ref erence level for optimum display simply press AUTO SCALE Signals are autoscaled once when the softkey is pressed and not on a continual basis If you change th
11. ON OFF CLEAR DISPLAY 2 29 Note Application Tutorials Tutorial 9 Constructing a Low Pass Filter from a Transfer Function Tutorial 9 Constructing aLow Pass Filter froma Transfer Function This procedure builds a fourth order Bessel Thomson filter characterizing SONET SDH transmitters operating at 2 48832 Gbit sec The filter is loaded into channel 1 user correction data The user correction data is based on the transfer function 105 Ho AE eA oo Gp dan ae Ax 105 105y 45y 10y y p where y 2 1140p p jw w w L 5nrfo fo bitrate This tutorial of manually constructing a filter is useful as an example To aid in the construction of 4th order Bessel Thomson filters at other frequencies use the MAKEFILT program located on the IBASIC UTILITIES FOR 71500 SERIES memory card This card is supplied with the jitter and eye diagram analyzer Construct the Filter For this example f 2 48832 Gbit sec To construct the filter press MENU Config TRACE POINTS and Enter 256 more 1 of 3 LINES DOTS LINES Set an appropriate frequency range for the filter frequency points by setting the span to 2 f0 This is 803 75514 ps for this example Press Main SEC DIV and enter 803 75514 ps Application Tutorials Tutorial 9 Constructing a Low Pass Filter from a Transfer Function 3 Turn the display off by pressing Traces select TR1 di splay ON OFF OFF 4 Build the equation by
12. Use INTERNAL for most system configurations Refer to the configuration manual for more information Selects the HP7 82 A internal 1 MHz reference Connect the source 10 MHz input to the HP7 B20A 1 MHz output Selects the 0 MHz input to the HP7 B2 A Connect the HP7 B2 A 1 MHz input to the system 0 MHz reference instal3 4 The following screen should be displayed Notice that the eye diagram analyzer s left side Setup menu is selected Setup Trg Cal Traces Measure Markers Masks Mass Storage diagram EYE READ PAT GEN a CH2 is Flease use this setup procedure Connect the DATA OUT to Channel 1 BIT Connect the CLOCK OUT or TRIGGER OUT INTEL hrough a 6 dB pad to Channel 2 If the pad is nat E dB enter the value with CH2 EXT ATTEN Trg Cal menu DELAY Set CHE is ta CLE OUT ar TAG OUT Setup menu Press READ PAT GEN Setup menu Press AUTOSCALE Traces menu eyef ltr Use DEFINE USER IF to save this state as ON OFF he Instrument Preset state Trg Cal menu CLEAR Press Instrument Preset ta exit this setup SO1SELAY 5 If you have not already connect the cables to the instruments front panels follow the instructions shown Otherwise proceed with If you have not already connect the cables to the instruments front panels follow the instructions shown Otherwise proceed with If you ha
13. 1982 A1 1985 EN 60555 2 1987 IEC 555 3 1982 A1 1990 EN 60555 3 1987 A1 1991 Supplementary Information The product herewith complies with the requirements of the Low Voltage Directive 73 23 EEC and the EMC Directive 89 336 EEC The HP 70820A Microwave Transition Analyzer was tested in HP 70004A Color Displays Safety qualification tests for these products were performed prior to 1 December 1993 Santa Rosa California USA 28 Dec 1995 _ Z Ll Dixof Browder Quality Manager European Contact Your local Hewlett Packard Sales and Service Office or Hewlett Packard GmbH Departrnent HQ TRE Herrenberger Strasse 130 D 71034 B blingen Germany FAX 49 7031 14 3143 Numerics 0 level description 3 4 1 Level description 3 4 10 MHz reference 1 11 70820A calibration 3 61 70820A clock control 3 21 70820A connections 1 13 70820A menus 3 14 70820A user corrections 3 49 70841A B pattern generator 1 24 A accessories 1 15 accessories required 1 14 add time delay 2 28 additional margin testing 2 20 Agilent 70820A menus 3 14 ALIGN command 4 4 align mask 3 32 amplitude and phase transitions 3 5 analysis eye diagram 1 2 application tutorials 2 2 apply user corrections 3 17 attenuator 1 15 attenuator required 1 14 automatic measurements 3 3 automatically load the personality 1 16 autoranging 1 11 AUTOST file 1 18 average trace 3 26 averaging submenu 3 27 B bandwidth to 40 G
14. ACQUIRE Data will be acquired once 8 To continually acquire and update the histogram press CONT ACQUIRE 2 37 Application Tutorials Tutorial 10 Create a Vertical Histogram f Pulsqen trace E TRI histag feapure VERTIEL NUMBER Tihle SAMPLES Sa SINGLE Vertical Zae ACQUIRE histogram CONT Carit ACQUIRE ther States a Os CHB ps div Tri Chi page 4B m div prev dof 2 8V ref menu Perform Statistical Analysis The range of sample points used to calculate the mean and standard deviation is the full screen 9 Tochange the limits press other UPPER LIMIT LIMIT 0 100 new upper limit value ENTER LOWER LIMIT LIMIT 0 100 new lower limit value ENTER Notice the values of the limit line positions are indicated at the top of the dis play Application Tutorials Tutorial 10 Create a Vertical Histogram Upper limit line ra Uti LBJ3 mY ViR Mat mY d 294 mY WINDOW Pulsgen piis ay _plel AN dps 180 HARKERL lower limit Heasura 143 125 w qRINOGH Table Analyze f Calib States r 1 1 results Bs POH psfdiv Tri Cht page YB al div prey 2of2 ref menu Lower limit line 10 To display a line indicating the location of the mean press results MEAN The mean and standard deviation values are also shown 2 39 Application Tutorials Tutorial 10 Create a Vertical Histogram 11 To display a line indicating the location of the standard deviation pr
15. CHE 4 CHICH CHeYCH1 Traces CHA MENL CHLe CHE CHEZ MENZ TABLE Scale ORRA CH2 CHL UCDRRE CHL CH2 NEML fa CHA CHE MENS HEN arkens CaNAGNCCHL CH2 MAGN MEN2 NAGNCMENS BILK 2 j 2 BLB56 FREQ 2 4B932E9 3 1057 C1B5 TR2 105 TRe 45 Res Lee TRE huild Config nn page aes RETURN 15 Continue by pressing RETURN Scale AUTO SCALE page 1 of 2 Calib user corr Pulsgen eA CHe SSeS H P lt l usr cor easure Pel ON OFF Table l SEL EDT FART SLOPE FREQ MAGN PHASE next FREQ Analyze FLAT de value H W dB 4B8 deg slope de value H BH dB Q 48 deg slope INSERT Galib 24 42Ap MHz B B1 dE AAB deg slope LINE 248 4300 MHz B BS dB G e deg slope 373 c500 MHz B 11 dB 4 01 deg slope States 157 66AB MHz B 19 dB H 43 deg slope ather fed ABAE MHz B ai dB 4 05 deg slope 746 3000 MHz B44 dB Q 86 deg slope page 870 9106 MHz B 6i dB A AE reg 5 0PE prev 2 of p 953 3348 MHz B BA dB 4 04 deg slope menu Application Tutorials Tutorial 9 Constructing a Low Pass Filter from a Transfer Function 16 To store the filter to a memory card press States more 1 of 2 mass storage 17 If the mass storage device needs to be selected refer to Saving to Mass Storage on page 3 34 18 Save the user corrections by pressing save SAVE USR COR 19 To restore the instrument settings press INSTR PRESET App
16. Control the Display s Clock Press DISPLAY Misc clock e If you want to turn the clock display on and off press CLOCK DISPLAY If you want to select US or European display format press US EURO e If you want to change the time or date press set clock Enter the new value in the same format as displayed Note To Compensate for dc Offsets To Calibrate IF for Accuracy CAUTION Eye Diagram Analyzer Reference Calibrating the Eye Diagram Analyzer Calibrating the E ye Diagram Analyzer For information on user corrections and instrument calibration data refer to Agilent 70820A User Corrections on page 3 49 and refer to Agilent 70820A Calibration on page 3 61 An offset calibration routine is provided that allows the eye diagram analyzer to compensate channel 1 for any external or internal dc offsets This ensures accurate measurements of the laser s one and zero levels For example you can use the calibration to remove any offset that may be present in an optical to electrical converter This is sometimes referred to as the dark level To perform an offset calibration Turn the laser off and then press Trg Cal OFFSET CAL CONT The calibration takes about a minute to execute When the calibration is finished DC NULL done is displayed Turn the laser on The 70820A microwave transition analyzer module provides separate auto matic IF calibration routines for channel 1 and channel 2
17. Diagram Analysis Setup SINGLE DENT eee figs a o DAU Aa Traces 3 Please use this setup procedure Measure 7 Cannect the DATA OUT to Channel 4 CHL EXT Connect the CLOCK OUT or TRIGGER OUT ATTEN hrough a dB pad to Channel 2 If the pad is not 6 dB enter the value CH2 EXT Markers mith CHE EXT ATTEN Trg Cal menu ATTEN Set CHE ig ta CLE OUT or TAG OUT Setup menu Press READ PAT GEN Setup menu Masks Press AUTOSCALE Traces menu OFFSET Use DEFINE USER IP to save this state as CAL he Instrument Preset state Trg Cal menu ass mare Storage Press Instrument Preset ta exit this setup iaf 2 3 Turn the display off and select trace one by pressing Traces display ON OFF OFF select TR1 Move the To move the measurement plane press ll Trg Cal CH1 EXT ATTEN and enter the attenuation on channel 1 input Optional Step Save Instrument State as Preset State 1 Select the Traces menu and scale the screen to the displayed signal by pressing Traces AUTOSCALE 2 Save the current instrument state by pressing Trg Cal more 1 of 2 DEFINE USER IP CONT The current instrument state is saved including the pattern generator s HP MSIB address the frequency reference scaling and trigger level Whenever INSTR PRESET is pressed the eye diagram analyzer is automatically placed in these settings Getting Started St
18. Specifications and Characteristics Definitions of Terms Specifications and Characteristics Specifications and Characteristics Specifications and Characteristics This chapter contains specifications and characteristics for the 71501C and 70874C Jitter and Eye Diagram Analyzer The distinction between specifications characteristics typical performance and nominal values is described as follows e Specifications describe warranted performance over the temperature range 0 C to 55 C unless otherwise noted All specifications apply after the in strument s temperature has been stabilized after 1 hour continuous opera tion and self calibration routines have been run Unless otherwise noted corrected limits are given when specifications are subject to minimization with error correction routines e Characteristics provide useful but nonwarranted information about the functions and performance of the instrument Characteristics are printed in italics e Typical Performance where listed is not warranted but indicates performance which most units will exhibit e Nominal Value indicates the expected but not warranted value of the param eter Specifications and Characteristics Vertical Specifications Vertical Specifications Table 5 1 Vertical Specifications Bandwidth 3 dB 20 GHz extended BW off 40 GHz extended BW on dc accurachy 45 C from cal The larger of 2 of signal ampltiude or 500 p
19. States R 1 A 1 results Bs COB psfdiv TrisCht page 4A ml div prey fof 2 aY ref menu 10 To display a line indicating the location of the mean press results MEAN The mean and standard deviation values are also shown Application Tutorials Tutorial 11 Create a Horizontal Histogram 11 To display a line indicating the location of the standard deviation press Statistical results fa T i 5B 6 ps Tle S04 ps dT 569 ps Pulsgen pti OX plel 106 dp 100 MEAN Measure STD DEV mean 22p 7 349 ps A AT etd dev 19B ps Table i Analyze f Calib States R f f L Bs POH psfdiv Tri Chi page YB div prev 2of2 AY ref menu Line indicating mean value 2 45 Application Tutorials Tutorial 11 Create a Horizontal Histogram E ye Diagram Analyzer Reference Eye Diagram Analyzer Reference Eye Diagram Analyzer Reference E ye Diagram Analyzer Reference In this chapter you will find information on the following topics Performing Eye Diagram Measurements 3 3 Generating Histograms 3 7 Masks and Limit Lines 3 9 Eye Diagram Menu Maps 3 12 Agilent 70820A Menus 3 14 Controlling the Display 3 16 Calibrating the Eye Diagram Analyzer 3 23 Displaying Traces 3 25 Using Markers 3 30 Applying Mask Testing 3 31 Saving to Mass Storage 3 34 Creating Copies of the Display 3 47 Agilent 70820A User Corrections 3 49 Agilent 70820A Calibration 3 61 Eye Diagram Analyzer Reference Perfo
20. To Extend the Bandwidth to 40 GHz To Apply User Corrections Eye Diagram Analyzer Reference Controlling the Display In eyeline mode additional eye filtering can be applied to improve the mea surement sensitivity This can be an advantage when measuring extinction ratios on low level signals Use the eyefltr ON OFF softkey to apply the filter When the pattern repetition frequency is greater than 10 MHz internal filter ing is applied that provides a 20 dB signal to noise improvement F or pattern repetition frequencies less than 10 MHz software filtering is applied that allows variable signal to noise improvement versus sweep time To improve sensitivity press Setup diagram EYELINE or PATTERN eyefltr ON OFF ON Use the front panel knob to adjust the amount of filtering applied Use the extd BW ON OFF softkey to enable RF corrections which extend the measurement bandwidth of the eye diagram analyzer to 40 GHz Extended bandwidth operation can be used in both eyeline and pattern modes but not in eye mode Extend the measurement bandwidth by pressing Setup diagram EYELINE or PATTERN The extended 40 GHz bandwidth cannot be used in eye mode Turn the extended bandwidth on by pressing Trg Cal more 1 of 2 extd BW ON OFF ON User corrections provide a convenient method for modifying the display of input signals Some of the applications for user corrections include the follow ing Filtering input signals to simulate
21. Trace memory registers can be used as a third channel Eye Diagram Analyzer Reference Generating Histograms Generating Histograms The 70820A can perform statistical analysis on any displayed trace After cre ating a vertical or horizontal histogram of the trace data the display can show mean and standard deviation values of the histogram Histogram analysis is performed using the Histogram menu Press MENU the left side page 1 of 2 Analyze Histogm The 70820A menus perform vertical or horizontal histograms on any single trace You can control the number of samples taken the window for valid data sam ples and the sample bounds for calculating mean and standard deviations Selects a trace for z A U1 180 nU VtRI 108 aU dU 280 nU E a Pulsgen p i GY plel 140 dp iBA TR1 an r 1 T 1 r 1 r Selects Misti oe Pape nean 1 366 al VERTICL yp std dev 54 7 mY 7 Tabl NUMBER Changes one sanPLes data samples SINGLE Analyze ACQUIRE Obtains histogram 4CONT data calit ACQUIRE Vertical 7 Process A Stat T 1 1 fi A A A A ather histogram araa y TETIN data and Trt Cht show page 25 mVfdiv Prey results 2of OY ret menu u The Histogram M enu yY HO U RP WN Eye Diagram Analyzer Reference Generating Histograms When generating histograms you must perform the following basic steps Select a trace Select histogram type Enter the number of samples Set limits for acquire
22. Trigger Mode CLOCK 7 32 AMPLTD trg 0 P Internal Clock Freq 2 488 320 008 Hz DATA clk o p HI LEYL Asp HI Lvl Atten Tern DAT 0 P misc Data 600 0 ay 0 080 V 0 dB OY DELAY Clock 500 0 ay 0 008 V 6 8 dB ay Data Output ON Delay s Optimize DATA DAT 0 P ON OFF fore patgen 1 of 2 An Example 70841A B s Status Screen b Use the front panel knob to scroll the box to the column where the To Manually Set the Trigger Level 1 Getting Started Steps for Setting Up Eye Diagram Analysis 70841A B appears c Press ADJ UST ROW and rotate the knob to move the box to the row where the 70841A B appears d Press ASSIGN BOTH Use the displayed softkey menus to set the pattern generator to the desired settings For an example refer to the paragraph Configure the data signal in Chapter 2 Application Tutorials To return control to the eye diagram analyzer press DISPLAY NEXT INSTR To return to the eye diagram analyzer personality menus press USER If a pattern generator other than the 70841A B is used you must use the fol lowing procedure to manually set the trigger level Select trace two and turn the display on by pressing gt prev menu select TR2 display ON OFF ON Automatically scale the trigger trace and set the trigger level by pressing AUTO SCALE Trg Cal LEVEL Use the knob to position the trigger level indicator line so it crosses an edge Getting Started Steps for Setting Up Eye
23. Values of Program Variables Variable Data Type Value Command string DIAGRAM string EYE Param EYELINE PATTERN Response string DONE Example OUTPUT M ta PROG STR Param EYELINE OUTPUT M ta PROG STR Command DIAGRAM OUTPUT M ta PROG W AIT ENTER M ta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT EXTIN The EXTIN command string performs an extinction ratio measurement The Response variable is loaded with two floating point numbers The first number is the linear ratio The second number is the logarithmic value Values of Program Variables Variable Data Type Value Command string EXTIN Param There are no parameters for this command Response string Two floating point numbers Example Example Programming Commands Introduction OUTPUT M ta PROG STR Command EXTIN OUTPUT M ta PROG W AIT ENTER Mta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT MARGIN The MARGIN command string sets the margin percentage limit for margin mask testing Load the Param variable with a floating point number that spec ifies the percentage over standard mask to test The range of margin is 0 to 100 percent Values of Program Variables Variable Data Type Value Command string MARGIN Param floating point number 0 to 100 example 25 6 Response string DONE OUTPUT M ta PROG NUM
24. contained on the memory card by pressing Mass Storage Rotate the front panel knob to highlight the desired file User correction files are identified by the prefix a_ Eye Diagram Analyzer Reference Controlling the Display Setup Trg Cal Traces Pref ix Measure HEI HP MSIB 4 Fage 1 AUTOST ASCII 1289 a btc4HBde ASCII 153b Markers a bt G2eH8 ASCII 1546 a_bt_15552 ASCII 1596 HPF B V4A ASCII 112k tend af catalog Masks g STATE Hass SAVE Storage MSK LIM 4 Load the file by pressing LOAD FILE The file is loaded when user corrections loaded is displayed on the screen 5 Turn the user correction function on by pressing Trg Cal more 1 of 2 usr cor ON OFF ON 3 19 To View 70820A Menus To Return to the J itter Analyzer or Eye Diagram Analyzer To Preview Programming Commands To View the Firmware Date Code Eye Diagram Analyzer Reference Controlling the Display usr cor Setup ON OFF extd BW Trg Cal ON OFF orng Traces OFF Measure REF INE Markers R IP CODE Masks a Bs 100 469 pa div VERSION Tri Cht Nass aB mfdiv mare Storage 244 mY ref 2af p User Corrections Applied to the Data Press MENU Press USER If the eye diagram analyzer s menus are not displayed load the program as explained in Chapter 1
25. division setting then set the sweep time using the Main menu s SEC DIV softkey trace length 20 F stop seconds division where trace length is determined by pressing TRACE POINTS in the Configuration menu Foss equals the desired stop frequency in hertz For example to set the stop frequency to 5 GHz with 512 trace points set the time scale to 5 12 ns per division This formula also determines the frequency scale of any time domain trace that has been formatted to the frequency domain using an F FT The advantage of using a trace formatted using an FFT is that the displayed upper frequency limit can be higher than the available range of many RF sources To View User Corrections Eye Diagram Analyzer Reference Agilent 70820A User Corrections 1 To view user corrections press MENU 2 To enter the Traces menu press Traces 3 Select a trace and then press input 4 Use the front panel knob to scroll the menu bar to UCORRI as shown in the following figure UCORR1 sets the trace to user correction data for channel 1 UCORR2 sets the trace to user correction data for channel 2 Nain TRA UCORRL CHL Tri CH1 CHa rigger Z CHE 3 4 CHL CHE CHEYCH1 Traces CH1 MENL CHICHE CHE MENZ TABLE Scale 1 Che CHt UCORRE CHL CH2 NEML Ais CHA CHE MENS NEN arses CaNAGNCCHL CH2 MAGNONEN2 NAGNCMENS EIK Config page hee RETURN 5 Press the RETURN softkey 6 To enter
26. for Removing the effects of frequency response roll off due to the optical to electrical converter and cables Simulating hardware filters recommended for laser transmitter evaluation such as 4th order Bessel Thomson filters The eye diagram analyzer must be in eyeline mode to apply user corrections In eyeline mode each sweep produces a continuous trace with the points con nected This is opposed to unconnected dots with the eye mode Eyeline mode is especially useful for measuring variations in laser turn on delay over shoot and ringing and for applying user frequency corrections The compati ble mode is eyeline Several Bessel Thomson software filters are included on the 70874A eye dia gram analyzer s memory card These filters can be applied as user corrections in the eyeline and pattern modes User corrections must be off in eye mode User correction files are identified by the prefix a_ as shown in the following table Two additional files on the card AUTOST and 70874 comprise the eye diagram analyzer program Supplied User Correction Files File Name File Data a_bt248832 Ath order Bessel Thomson filter for 2 48832 Gbit sec transmission a_bt_62208 Ath order Bessel Thomson filter for 622 08 M bit sec transmission a_bt_ 15552 4th order Bessel Thomson filter for 155 52 M bit sec transmission Application Tutorials Tutorial 5 Use Software Filters usr cor
27. for the card is the same address as the display s GPIB address and is normally set to 4 If the address is not correct enter the correct address using the numeric keypad Use this procedure to save a file in the default memory To select default mem ory refer to Selecting and Formatting Memory on page 3 34 Display the Mass Storage menu by pressing MENU page 1 of 2 States more 1 of 2 mass storage save Perform one of the following If you are saving an instrument state user correction or histogram press the appropriate softkey If you are saving a trace press save trace Select the trace and then use the VEC F MT softkey to determine if the trace data is saved as complex data VEC or scalar data FMT Press save If you are saving a channel calibration mask limit line user defined key all recall registers press save misc and then the appropriate softkey 3 Enter the desired file name To save the file press ENTER LINE An HP IL keyboard is recommended to simplify the task of entering alphanu meric information This keyboard plugs into the jack provided on the display s front panel Order the Agilent 46021A keyboard Eye Diagram Analyzer Reference Saving to Mass Storage Entering a File Name without a Keyboard a Turn the front panel knob to move the character select cursor b Press SELECT CHAR to enter a character at the character select cursor c Press the numeric keypad to enter numbers or a minus
28. histogram data below the relative 50 point of the peaks This measurement is the mean and sigma of the one level determined from a 20 window of a bit interval centered in the middle of the bit This measurement is the mean and sigma of the zero level determined froma 20 window of a bit interval centered in the middle of the bit This measurement is the difference between the mean minus three sigma of the one level and the mean plus three sigma of the zero level Crossing Level Eye Width Eye J itter o Mean Rise Time Mean Fall Time Eye Diagram Analyzer Reference Performing Eye Diagram M easurements This measurement is the amplitude that the one level and zero level cross It also expresses the level as a percentage of the mean one level and mean zero level difference This measurement is the eye width determined from the bit period and the eye jitter On the eye the edges are defined to be the left crossing point plus three sigma and the right crossing point minus three sigma This measurement is the sigma of a horizontal histogram at the crossing point This measurement is the mean time interval between a horizontal histogram centered at the lower threshold point and a horizontal histogram centered at the upper threshold point on arising edge of an eye diagram This measurement is the mean time interval between a horizontal histogram centered at the upper threshold point and a horizontal histogram centered at th
29. inch CS80 compatible such as an 9122 To use the drive you must connect it and enter its GPIB address using DISPLAY menu softkeys The procedure in this section shows you how to do this You will need to know the disk drive s GPIB address unit number and volume number The GPIB address is represented by a digit from 1 through 7 The unit number indicates an individual slot in the disk drive Although unit numbers can range from 0 through 9 they are typically 0 or 1 The volume number is used for hard disk drives For reading diskettes the volume number should be 0 Insert the memory card into the front panel card slot of the microwave transition analyzer facing the metal strip on the card downward and toward the instrument Make sure the card is fully inserted into the card slot Select the memory card as the mass storage device by pressing DISPLAY Mass Storage msi MEMORY CARD To display a catalog of the files on the memory card press MENU page 1 of 2 States more 1 of 2 mass storage msi HP MSIB CARD If the message 6218 catalog open failed is displayed the card is not in the front panel card slot The HP MSIB address for the card is the same address as the display s GPIB address and is normally set to 4 If the address is not correct enter the correct address using the numeric keypad CAUTION To Use an Internal RAM Disk To Use an GPIB Disk Drive Eye Diagram Analyzer Reference Saving to Mass Stora
30. next FREQ field in the lines of data must be set to slope To Copy User Correction to Alternate C hannel Eye Diagram Analyzer Reference Agilent 70820A User Corrections Copy user correction to an alternate channel by pressing MENU page 1 of 2 Calib user corr other copy to CH2 If channel 2 data is selected the softkey reads copy to CH1 Viewing User Correction Data This section explains how to assign user correction data to a trace This allows you to view the data graphically Graphically displaying the data is especially helpful when you are designing a custom filter When a trace is assigned to user correction data the display s horizontal axis automatically changes to fre quency The technique used to control the frequency scale depends on the microwave transition analyzer s sweep mode Set the Frequency Scale for Frequency Sweeps When using a frequency sweep the frequency scales of the microwave transi tion analyzer and the user correction trace are identical The start and stop frequencies are the same This includes any frequency offset Set the Frequency Scale for Time Sweeps When the microwave transition analyzer is performing time sweeps the fre quency scale of any user correction trace is related to the sweep time The start frequency is set to 0 Hz The stop frequency is determined by the sec onds per division setting To set the stop frequency use the following formula to determine the seconds per
31. no exception When you use improper cleaning and handling techniques you risk expensive instrument repairs damaged cables and compromised measurements Before you connect any fiber optic cable to the Agilent 71501D clean it thoroughly This product is designed for use in Installation Category II and Pollution Degree 2 per IEC 61010 1C and 664 respectively Always use the three prong ac power cord supplied with this instrument Failure to ensure adequate earth grounding by not using this cord may cause instrument damage This instrument has autoranging line voltage input Be sure the supply voltage is within the specified range Use of controls or adjustment or performance of procedures other than those specified herein may result in hazardous radiation exposure Contents 1 Getting Started Steps for Setting Up Eye Diagram Analysis 1 4 2 Application Tutorials Tutorial 1 Measure Eye Parameters 2 4 Tutorial 2 Measure in Optical Power Units 2 8 Tutorial 3 Measure Extinction Ratios on Low Level Signals 2 10 Tutorial 4 Measure Laser Turn on Delay 2 13 Tutorial 5 Use Software Filters 2 15 Tutorial 6 Test to Industry Standards 2 19 Tutorial 7 Default and Custom Mask or Limit Line Testing 2 23 Tutorial 8 Display the Data Pattern 2 27 Tutorial 9 Constructing a Low Pass Filter from a Transfer Function 2 30 Tutorial 10 Create a Vertical Histogram 2 36 Tutorial 11 Create a Horizontal Histogram 2 41 3 Eye Diagram Analyzer Refere
32. pressing select TR2 input build eqn CLR END SEL EDT SEL 5 Turn the front panel to highlight the j operand and then press INSERT Continue using this technique to construct the trace equation shown in the following figure Enter numbers using the front panel numeric keypad Hain Trigger Traces Scale Markers Config page tof 2 mow ee r e Ea fez d156 F REQ 2 4889265 l ACE LYE ANL DEL DEL EGO FTC FF dxf PJE FTE FHE FTE FTE IMAGE INTEGI MAGHI REALI SIGNI SORT SUMI TOO Fsig Fear CH1 CHE MEMI MEME NENA NENY TRA TR3 TRY e j n PI TIME FREQ POWER o Mouse CHOP CONY CORR Noo SHIFT YS SEL EDT DELETE CLRPEND RETURN prev menu 2 31 Application Tutorials Tutorial 9 Constructing a Low Pass Filter from a Transfer Function 6 Build the trace equation shown in the following figure by pressing RETURN select TR3 input build eqn CLR END SEL EDT SEL Build the trace equation Notice the cursor has wrapped to the following line Be sure to include the last two right parenthesis characters shown on the last line Nain TRI 105 105 TRP 1A5 TR2 t45 TR2 11A TR2 SEL EDT im finor 0 IMNAG CH1 a ACI INTEG CHE o pee ANALY MAGNO MENL L ATAN REAL MENZ h Traces DELO SIGNO NENA Say Oct SORT MENY E DEGI SUMO TRI Scale DFT TO TRE ts DIFFU TRY d fdx
33. sign d TheINSERT or softkey determines the action of the SELECT CHAR soft key Choices are INSERT acharacter REPLACE an existing character or DELETE acharacter e Press the and U keys beneath the front panel knob to move the com mand entry cursor f Use the CLEAR TO END softkey to remove characters from the command entry cursor to the end of the command To Recall a File Use this procedure to recall a file from the default memory To select default memory refer to Selecting and Formatting Memory on page 3 34 1 To recall a file press MENU page 1 of 2 States more 1 of 2 mass storage Rotate the front panel knob to select highlight the desired file 2 Load the file by pressing LOAD FILE To Erase a File Use this procedure to erase a file in the default memory To select default memory refer to Selecting and Formatting Memory on page 3 34 1 To erase a file press MENU page 1 of 2 States more 1 of 2 mass storage Rotate the front panel knob to select highlight the desired file 2 To erase the file press more PURGE FILE ENTER LINE To Eraseall Files CAUTION To Change the Prefix Eye Diagram Analyzer Reference Saving to Mass Storage This procedure erases all files stored in default memory To erase all files in default memory press MENU page 1 of 2 States more 1 of 2 mass storage more FORMAT To modify the prefix press MENU page 1 of 2 States more 1 of 2 ma
34. the Main menu press Main 3 57 10 Eye Diagram Analyzer Reference Agilent 70820A User Corrections Set the frequency scale of the user correction trace e If the microwave transition analyzer is set for a frequency sweep use the Main menu s START and STOP softkeys e If the microwave transition analyzer is set for a time sweep press the Main menu s SEC DIV softkey and enter the sweep time to set the stop frequen cy The formula to determine the sweep time is provided at the beginning of this section To enter the Scale menu press Scale Press the REF LEV POS softkey and set the reference level to correctly position the trace on screen Change the vertical amplitude scale if needed by pressing SCALE Calib user corr The user correction data is now displayed graphically above the data Pulsgen eA CHe E N Table t SEL EDT F ENEE SLOPE Analyze FREQ MAGH PHASE next FREQ T de value H H dB 4B8 deg slope 1 966240 GHz 3 HL dB Q 48 deg slope INSERT Galib 2 4B9320 GHz 5 71 dB AAB deg slope LINE 4 976648 GHz 21 50 dB G 40 deg slope 1BA ABAB GHz 21 50 dB 4 08 deg States ather page prev fot p menu To Save a User Correction File Eye Diagram Analyzer Reference Agilent 70820A User Corrections Saving Recalling and Cataloging User Correction F iles User correction data can be saved in files and recalled for lat
35. the effects of circuit design Compensating for frequency and phase response of external probes e Compensating for frequency and phase response of external test setups Compensating for the frequency response of optical to electrical converters Several Bessel Thomson software filters are included on the 70874A eye dia gram analyzer s memory card These filters can be applied as user corrections in the eyeline and pattern modes User corrections must be off in eye mode User correction files are identified by the prefix a_ as shown in the following table The files AUTOST and 70874 comprise the eye diagram analyzer pro gram Eye Diagram Analyzer Reference Controlling the Display To learn more about these files and about creating and applying user correc tions refer to Tutorial 5 Use Software Filters on page 2 15 User Correction Files File Name File Data a_bt248832 Ath order Bessel Thomson filter for 2 48832 Gbit sec transmission a_bt_ 62208 4th order Bessel Thomson filter for 622 08 M bit sec transmission a_bt_ 15552 Ath order Bessel Thomson filter for 155 52 M bit sec transmission Place the 70874A eye diagram analyzer memory card in the front panel card slot The 70874A eye diagram analyzer must already be loaded into memory Display the eye diagram analyzer s menus by pressing USER Setup diagram EYELINE or PATTERN User corrections can not be applied in eye mode Display a catalog of the files
36. trace position 3 26 trace scale 3 26 traces display 3 25 displayed 3 25 persistence modes 3 27 position and scale 3 26 traces displaying 3 25 traces measure markers masks and mass storage menus 3 13 transfer function constructing a low pass fil ter 2 30 Index 5 Index trigger level manually set 1 25 trigger source 1 22 trigger menus 3 12 turn calibrator signal on 3 70 turning off RF correction 3 62 tutorials application 2 2 constructing a low pass filter from a transfer function 2 30 create a horizontal histogram 2 41 create a vertical histogram 2 36 default and custom mask or limit line testing 2 23 display the data pattern 2 27 extinction ratios on low level signals 2 10 eye parameters 2 4 measure laser turn on delay 2 13 measurement in optical power units 2 8 test to industry standards 2 19 use software filters 2 15 two masks displayed on screen 3 9 U user correction files supplied 2 15 user correction applied to data example 2 16 files 1 9 modes available 1 5 user correction file erase 3 60 recalling 3 60 saving 3 59 user correction files 3 18 user correction files 3 18 user corrections 70820A 3 49 applying 3 17 channel selection 3 51 copy to alternate channel 3 56 delete a channel 3 52 displayed 3 20 entering and editing 3 52 example 3 50 menu 3 51 on off 3 51 user corrections applied to the data 3 20 user error in pa
37. update on the pattern trigger This insures the trace on the screen remains the same from sweep to sweep In this mode trace averaging can be used for more repeatable mea surements on noisy signals Masks and limit lines can be used with the pattern mode and are useful for testing specific portions of the data sequence for mask or template violations This can uncover violations that happen only when a specific pattern of ones and zeros occur The compatible mode is Pattern Select Pattern Mode Press INSTR PRESET If you are using an 70841A B pattern generator connect the TRIGGER OUT signal to the 70820A module s RF INPUT 2 connector This procedure uses the eye diagram analyzer s pattern mode In pattern mode the trigger signal must come from the TRIGGER OUT and not the CLOCK OUT connector The pattern mode only works with a pattern trigger and not with a clock signal The pattern trigger is derived from the clock signal divided by the pattern length Select the pattern mode by pressing Setup diagram PATTERN Notice the CH2 is softkey label has changed to indicate that the trigger source is connected to the TRIGGER OUT signal Select the bit interval and the delay by pressing BIT INTVL and enter 20 Traces Turn autoscaling on by pressing AUTO SCALE The display should look like the following figure Application Tutorials Tutorial 8 Display the Data Pattern
38. 7 19 for other agencies Exclusive Remedies The remedies provided herein are buyer s sole and exclusive remedies Agilent Technolo gies shall not be liable for any direct indirect special inci dental or consequential dam ages whether based on contract tort or any other legal theory Safety Symbols CAUTION The caution sign denotes a hazard It calls attention toa procedure which if not cor rectly performed or adhered to could result in damage to or destruction of the product Do not proceed beyond a cau tion sign until the indicated conditions are fully under stood and met WARNING The warning sign denotes a hazard It calls attention to a procedure which if not cor rectly performed or adhered to could result in injury or loss of life Do not proceed beyond a warning sign until the indicated conditions are fully understood and met The instruction man Z ual symbol The prod uct is marked with this warning symbol when it is necessary for the user to refer to the instructions in the manual The laser radiation symbol This warning symbol is marked on products which have a laser output The AC symbol is used to indicate the required nature of the line module input power m The ON symbols are used to mark the posi tions of the instrument power line switch o O The OFF symbols are used to mark the positions of the instru ment power line switch The CE mark is a reg i
39. Agilent 71501D Eye Diagram Analysis User s Guide J e e o e ee a Mes Agilent Technologies Copyright Agilent Technologies 2002 All Rights Reserved Repro duction adaptation or trans lation without prior written permission is prohibited except as allowed under copy right laws Agilent Part No 70874 90023 Printed in USA May 2002 Agilent Technologies Lightwave Division 3910 Brickway Boulevard Santa Rosa CA 95403 USA Notice The information contained in this document is subject to change without notice Com panies names and data used in examples herein are ficti tious unless otherwise noted Agilent Technologies makes no warranty of any kind with regard to this material includ ing but not limited to the implied warranties of mer chantability and fitness for a particular purpose Agilent Technologies shall not be lia ble for errors contained herein or for incidental or conse quential damages in connec tion with the furnishing performance or use of this material Restricted Rights Legend Use duplication or disclo sure by the U S Government is subject to restrictions as set forth in subparagraph c 1 ii of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 for DOD agencies and sub paragraphs c 1 and c 2 of the Commercial Computer Software Restricted Rights clause at FAR 52 22
40. B Param 25 6 OUTPUT M ta PROG STR Command M ARGIN OUTPUT M ta PROG W AIT ENTER Mta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT MARMSK The MARMSK command string turns on or off margin mask testing 4 9 Example on oOo U RP WN P Programming Commands Introduction Values of Program Variables Variable Data Type Value Command string MARM SK string ON Param OFF Response string DONE OUTPUT M ta PROG STR Param ON OUTPUT M ta PROG STR Command M ARM SK OUTPUT M ta PROG W AIT ENTER M ta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT MEAS The MEAS command string performs the following eight measurements on the eye mean 1 level mean 0 level eye height crossing level eye width eye jitter mean rise time mean fall time The Response variable is loaded with eight floating point numbers Each num ber is the result of one of the eight measurements The numbers are ordered according to the list shown above Programming Commands Introduction Values of Program Variables Variable Data Type Value Command string MEAS Param There are no parameters for this command Response string example 25 1 14 2 9 67 2 23 8 91 4 5 2 11 6 7 Example OUTPUT M ta PROG STR Command M EAS OUTPUT M ta PROG W AIT ENTER Mta A OUTPUT M ta PROG STR Response EN
41. During mask t Setup Traces Trg Cal i menu ee Measure f Markers Masks Mass Storage Traces e amplitude of the signal it will not be autoscaled esting trace 4 is reserved for the error trace 1 1 f f 1 persist 7 menu Bes 100 469 ps div Persistence Trt Chi Averaging di Ge A a Tr average menu To Display a Trace Press Traces select TR1 TR2 TR3 or TR4 display ON OFF ON To Position and Scale Each Trace To Average Trace 1 Eye Diagram Analyzer Reference Displaying Traces The selected trace can be positioned vertically on the display This is accom plished using the REF LEVIPOS softkey to enter both the reference position and reference level The reference position POS is entered as a percentage of the verti cal display The top of the screen is 100 The bottom of the screen is 0 The ref erence level REF LEV is the amplitude value at the reference position To scale and position a trace press Traces AUTO SCALE to automatically scale the selected trace or SCALE to manually set the scale Use the front panel knob or numeric keypad to change the displayed vertical scaling REF LEV POS POS to move the trace s reference position Rotate the front panel knob to change the position REF LEV POS LEV to change the reference level at the trace s reference position Rotate the front panel knob to change the level The Traces menu s average sof
42. E NUMBER The volume number should be left at the default value of zero for floppy disk drives Continue by pressing MENU page 1 of 2 States more 1 of 2 mass storage msi HP MSIB CARD Although CARD is selected the display s GPIB disk softkey pressed in Step 3 redirected communications to the GPIB disk drive To Change a Memory Card Battery A WN rPe Eye Diagram Analyzer Reference Saving to Mass Storage The memory card s battery is a lithium commercial CMOS type part number CR 2016 The memory card should be installed when the battery is removed If the bat tery is removed while the card is not installed all data in the card will be lost Store memory card files on another device before changing the battery when extra care is appropriate a Write Protect Battery Groove Battery Switch Slot Clip pkb amp Install the memory card into the 70004A display On the front edge of the card locate the groove of the battery clip Gently pry the battery clip out of the card The battery fits inside the clip Replace the battery making sure the plus sign on the battery is on the same side as the plus sign on the clip Insert the battery clip into the memory card holding the clip as oriented in the figure Face the open edge of the clip toward the memory card s write protect switch Write the date the battery was replaced on the card Eye Diagram Analyzer Reference Saving to Mass Sto
43. EPS Masks persist OFF Mass Storage average prey menu average ONIOFF AVERAGE SWEEPS EXTINCT RATIO MEASURE EYE rif tim ONIOFF UPPER THRSHLD LOWER THRSHLD NUMBER SAMPLES OFF prey menu x1 x2 1 Y1 Y2 MARKERS OFF default masks display ONIOFF MASK ALIGN MASK MARGIN msk mar ONIOFF CLEAR MASKS prey menu mask setup test ONIOFF errors ONIOFF traces ONIOFF count TRCIDOT err tre ONIOFF STM 1 OC 3 STM 4 OC 12 STM 16 0C 48 PREV PAGE ENTER LINE NEXT PAGE SELECT CHAR INSERT REPLACE i ald LOAD FILE SPACE PURGE FILE DELETE CHAR SAVE STATE CLEAR TO END SAVE MSK LIM prey menu menu2 Traces Measure Markers Masks and Mass Storage M enus 3 13 Eye Diagram Analyzer Reference Agilent 70820A M enus Agilent 70820A Menus This section discusses the softkey menus for the 70820A microwave transition analyzer module To learn about the eye diagram analyzer s menus refer to Eye Diagram Menu Maps on page 3 12 These menus provide additional fea tures useful for running the eye diagram analyzer You will find the preview feature discussed in this chapter very useful It dis plays the programming command corresponding to the response received when most softkeys are pressed Most front panel controls are accessed via softkey menus Softkeys are the seven buttons located on each side of the screen The fu
44. Hz 3 17 battery memory card 3 39 BIT command 4 5 bits displayed 3 16 C cables 1 14 1 15 calibrate IF for accuracy 3 23 calibrating IF 3 64 calibrating the eye diagram analyzer 3 23 calibration 70820A 3 61 Index data 3 66 date 3 65 IF 3 64 menu 3 62 offset 2 5 calibration menus 3 12 calibrator frequency amplitude 3 70 calibrator signal control 3 69 calibrator signal on 3 70 care of fiber optics 1 iv catalog files 3 42 channel user correction 3 51 channels versus traces 3 6 CLEAR command 4 5 clock control 3 21 color grading persistence 3 28 command ALIGN 4 4 BIT 4 5 CLEAR 4 5 DEFAULT 4 6 DELAY 4 7 DIAGRAM 4 7 EXTIN 4 8 MARGIN 4 9 MARMSK 4 9 MEAS 4 10 PERSIST 4 11 QUIT 4 12 commands preview 3 20 compensate for dc offsets 3 23 configure data signal 2 2 connect the equipment 1 12 connections front panel 1 14 connections without a laser source and con verter 1 16 constructing a low pass filter from a transfer function 2 30 control the 70820A clock 3 21 controlling an 70841A B pattern generator 1 24 controlling calibrator signal 3 69 controlling the display 3 16 Converter laser and optical to electrical 1 15 copy of display 3 47 create a horizontal histogram 2 41 create a vertical histogram 2 36 create mask or limit line 2 24 Index 1 Index create print 3 47 crossing level description 3 5 custom keypad 1 3 custom mask or limit line testin
45. MENU Traces Turn on both trace 1 and trace 2 Set the input to trace 1 as channel 1 Set the input to trace 2 to channel 2 Display the IF correction data for each channel by pressing page 1 of 2 Calib IF calib cal debug show SHOW COR FFT or SHOW COR FIR Scale the traces by pressing page 2 of 2 Scale Select trace 1 and press AUTOSCALE Select trace 2 and press AUTOSCALE To View Hardware Response Traces Eye Diagram Analyzer Reference Agilent 70820A Calibration Channel 1 data tf ou Pulsgen FFT rl E ou ue FIR Table i Analyze F J i talib F Tee States i 1 1 f 1 f 1 1 a Hz 883 25 kWz div 8 83254 MHz Tri Chi Tr2 Che page 4 dB div 1 9 dBediv prev caf 2 11 2 dE ref 6 9 dE ref menu Channel 2 data Display the traces menu by pressing MENU Traces Turn on both trace 1 and trace 2 Set the input to trace 1 as channel 1 Set the input to trace 2 to channel 2 Display the 100 kHz filter response of stage 0 by pressing page 1 of 2 Cali b IF calib cal debug show SHOW CAL Scale the traces by pressing page 2 of 2 Scale Select trace 1 and press AUTOSCALE Select trace 2 and press AUTOSCALE Eye Diagram Analyzer Reference Agilent 70820A Calibration 7 To display the various hardware responses press page 1 of 2 SHOW CAL Use the front panel step keys to scroll through the various hardware responses Channel 1 data ta Pulsge
46. Mode Change to eyeline mode then turn filtering on by pressing INSTR PRESET Setup diagram EYELINE eyefltr ON OFF_ON BIT INTVL and enter 1 Set the persistence to infinite by pressing Traces persist INFINIT Trg Cal After several traces have been displayed press CONT STOP STOP Turn on the markers Press X1 and X2 to activate markers 1 and 2 5 Turn the front panel knob to move the markers to different transition crossing points on the waveform as show in the following figure This provides an easy method to check the peak to peak difference in the laser turn on time measured at the crossing point Notice in the following figure a delta reading of 30 ps is displayed at the top of the screen Application Tutorials Tutorial 4 Measure Laser Turn on Delay 1 74 3474 ps k2 44 28 65 ps X d L 48 1480 ps Setup 2 adjust Trg Cal 44 206536 ps Traces A i i A Neasure 4 a Af Markers Masks B s 40 185 ps div Trt Cht ass BA mW div Storage Jed mY ref Laser Overshoot and Turn On Delay Xi TRL Xo J TRL Y1 f off Ye f off MARKERS OFF Application Tutorials Tutorial 5 Use Software Filters Tutorial 5 Use Software Filters This tutorial enables a software filter The filter is designed with user fre quency corrections User frequency corrections can be used
47. OFF ON and enter 2 If T races is set to on the eye diagram analyzer stops sweeping when either the error or trace limit is reached Turn the number of traces function off by pressing 7 races ON OFF OFF Turn error tracing on by pressing err trc ON OFF ON Any trace which violates the mask shows on the lower half of the screen Reset and start the trace and error counters by pressing Application Tutorials Tutorial 6 Test to Industry Standards test ON OFF ON The instrument stops sweeping after two error traces have been accumulated Refer to the following figure Note that for this figure errors occur due to overshoot on a zero to one transition diagram Setup EYELINE Errors far stop gs Trg C iP MP oT AG EAD TE j PAT GEN Traces X ae fa He L CL i jR BIT easure INTUL Display of le error traces Harkers t W f DELAY Maska ap eyef ltr EEEREN 3a1 sde ps diy IIE Tri Chi Tr4 Errors Mi x ass 9A mW div B8 mW div LB 2 CLEAR Storage iBA mY ref 160 mW ref L3 Tr 137 DISPLAY Turn off Mask Testing 13 Turn off error tracing and the display by pressing err trc ON OFF OFF mask setup display ON OFF OFF Trg Cal CONT STOP CONT Application Tutorials Tutorial 7 Default and Custom Mask or Limit Line Testing Tutorial 7 Default and Custom Mask or Limit Line Testing The 70820A menus allow you to create and display up to eight limit lines and masks at
48. OTE prey menu 3 If the screen does not resemble the above figure press msi HP MSIB CARD prev menu DISPLAY Mass Storage msi MEMORY CARD MENU The list of files should now be displayed 4 Turn the front panel knob to highlight the file AUTOST and then press LOA D FILE If you load the 70874 file by mistake the message 7386 memory over flow may be displayed This error message is a result of the manual loading pro cess and in this instance does not indicate a problem The program still should be properly loaded Getting Started Steps for Setting Up Eye Diagram Analysis Step 3 Complete the Installation Using the Screen Instructions If the displayed screen looks like the figure on the left side of this page your system has been previously configured Press CONT and then continue with Step 4 Connect the front panel cables However if you wish to reconfigure your system press RECNFIG and continue with the following explanation of the self guided screens If the screen looks like the figure on the right side of this page the first self guided screen is displayed Perform the following steps Press 7084X if you are using an 70841A B pattern generator If using an 70843A or any other pattern generator press MANUAL If you press 7084X the screen shown on the following page is displayed The program automatically determines and displays the pattern generator module s HP MSIB address For
49. Optical If you have access to a laser and an optical to electrical converter use the to E lectrical connections shown in the following figure To protect the input connectors Converter use adapters between the cables and the connectors The laser is the device being tested Clock Out 6 dB ATTENUATOR Cables SMA to SMA Channel 1 SMA to SMA Channel 2 SMB to SMB 10 MHz Reference Miscellaneous 3 5mm f to 2 4 mm f two 6 dB attenuator LIGHTWAVE CONVERTER Optical Input p n 8120 4948 p n 8120 4948 p n 8120 5025 p n 1250 2277 8493C Connections without a Laser Source and Converter Automatically Load the Personality Note Getting Started Steps for Setting Up Eye Diagram Analysis If alaser source and optical to electrical converter are not available use the alternate connection shown in the following figure In this case the pattern generator s data output is displayed An electrical device could be inserted between the pattern generator and the eye diagram analyzer Channel 1 Channel 2 Data Out Clock Out o o o Clock Clock In Out pobSa 6 dB ATTENUATOR Step 2 Load the Personality 1 Insert the eye diagram personality card into the front panel card slot of the microwave transition analyzer facing the metal strip on the card downward and toward the instrument Make sure the
50. SWEEPS and enter 8 Turn autoscaling on by pressing prev menu AUTO SCALE The display should look similar to the display of a sampling oscilloscope See the following figure The large overshoot shown is a result of the particular laser bias setting used If the edges of the waveform are unstable in time indicating no trigger refer to the To Manually Set the Trigger Level on page 1 25 Application Tutorials Tutorial 1 Measure Eye Parameters select Setup TRA display Trg Cal ON OFF Traces SCALE i REF easure LEV IP03 AUTO Markers SCALE Masks persist B s 100 465 psfdiv Tri Chi ass gB m div Storage 256 mY ref average Example of a Large Overshoot Resulting from Laser Bias Perform an Offset Calibration This calibration procedure removes any offset that may be present in the opti cal to electrical converter This is sometimes referred to as the dark level The offset calibration ensures accurate measurements of the laser s one and zero levels Turn the laser off If you are measuring the pattern generator directly disconnect the input signal at channel 1 Perform the calibration by pressing Trg Cal OFFSET CAL CONT The calibration takes about a minute to execute When the calibration is fin ished DC NULL done is displayed Turn the laser on If you are measuring the pattern generator directly reconnect the input signal at c
51. States f 1 1 results Bes GB psfdiv Trt Cht page YB ml div prev 2af 2 ref menu Window marker 1 6 Enter the number of samples to be taken for the histogram by pressing prev menu NUMBER SAMPLES of samples ENTER The default number of samples taken is 1000 7 To draw the horizontal histogram press SINGLE ACQUIRE Data will be acquired once 8 To continually acquire and update the histogram press CONT ACQUIRE ca Pulsgen samples Measure 1888 Analyze Calib States Tri Cht page 4B ml div 2of2 ref Application Tutorials Tutorial 11 Create a Horizontal Histogram ACQUIRE L 1 ather PG psfdiv Horizontal histogram Perform Statistical Analysis The range of sample points used to calculate the mean and standard deviation is the full screen 9 Tochange the limits press prev menu other UPPER LIMIT LIMIT 0 100 new upper limit value ENTER LOWER LIMIT LIMIT gt 0 100 new lower limit value ENTER Notice the values of the limit line positions are indicated at the top of the dis play Application Tutorials Tutorial 11 Create a Horizontal Histogram Lower limit line Upper limit line a Ti 58 6 ps Ti2 504 ps dT 359 p WINDOW Pulsgen pild g p plel 4 sat dp 30 34 f HARKERL lower limit mini 58 394 ps 1 Heasure MARKERE UPPE Table r LIN LOWER Analyze CTAIT r LINIT i ax 100
52. TER M ta Response OUTPUT M ta PROG STAT CONT PERSIST The PERSIST command string controls persistence displays Persistence modes are available through the standard microwave transition analyzer remote commands however special color maps are necessary for proper dis play and are available only with Instrument BASIC Command parameters include INF VAR COLGRAD MONOGRAD and OFF Each parameter has the following action INF turns on infinite persistence mode e VAR turns on variable persistence mode e COLGRAD turns color graded persistence mode e MONOGRAD turns monochrome graded persistence mode OFF turns persistence mode off Programming Commands Introduction Values of Program Variables Variable Data Type Value Command string PRESIST string INF VAR Param COLGRAD MONOGRAD OFF Response string DONE Example OUTPUT Mta PROG STR Param COLGRAD OUTPUT M ta PROG STR Command PERSIST OUTPUT M ta PROG W AIT ENTER M ta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT QUIT The QUIT command string causes the eye diagram personality to terminate This command does not pause upon completion Values of Program Variables Variable Data Type Value Command string QUIT Param There are no parameters for this command Response There is no response from this command Example OUTPUT Mta PROG STR Command QUIT
53. UTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT Example Programming Commands Introduction BIT The BIT command string sets the instrument s time scale seconds per divi sion to a value which corresponds to the number of bits specified in the Param variable Values of Program Variables Variable Data Type Value Command string BIT Param floating point number example 3 5 Response string DONE OUTPUT M ta PROG NUM B Param 3 5 OUTPUT M ta PROG STR Command BIT OUTPUT M ta PROG W AIT ENTER Mta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT CLEAR The CLEAR command string clears the display for persistence mode or error trace mode CLEAR also restarts any trace averaging Values of Program Variables Variable Data Type Value Command string CLEAR Param There are no parameters for this command Response string DONE 4 5 Example Example Programming Commands Introduction OUTPUT M ta PROG STR Command CLEAR OUTPUT M ta PROG W AIT ENTER M ta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT DEFAULT The DEFAULT command string copies the default masks specified in the Param variable Select a mask from the following types STM 1 default mask for STM 1 STM 4 default mask for STM 4 STM 16 default mask for STM 16 OC 3 de
54. V The larger of 1 of signal ampltiude or 500 pV typical Noise floor at 1 GHz lt 1 4 MV ns 5 3 Specifications and Characteristics Input Channel Specifications Input Channel Specifications CAUTION Input channels RF INPUT 1 and RF INPUT 2 are dc coupled Table 5 2 Input Channel Specifications Operation input range lt 320 mB including dc offset Maximum safe input voltage 2 V without damage oe Number of input channels 2 Input connectors 2 4 mm male Nominal input impedance 500 Programmable dc offset 320 mV a Includes two 2 4 mm f to 3 5 mm f adapters Specifications and Characteristics Trigger Specifications Trigger Specifications Table 5 3 Trigger Specifications Operation input range lt 320 mV including dc offset Maximum safe input voltage WV A pk pk without damage Number of input channels 2 Input connectors 2 4 mm male Nominal input impedance 502 Programmable dc offset 320 mV a Includes two 2 4 mm f to 3 5 mm f adapters 5 5 Specifications and Characteristics Trigger Specifications Trigger Specifications Table 5 4 Trigger Specifications Trigger sensitivity dc 40 65 mV GHz typical pk pk J itter lt 2 5 ps rms Specifications and Characteristics Horizontal Specifications Horizontal Specifications These specifications are for the eye diagram analyzer only Table 5 5 Horizontal Specif
55. aces Sa JONI DFF pa eount Markers f TRC IDOT 4 L Hasks OKT ae 120 438 pe GB Pgp pe div OM Tri Cht Mi A Mass SB mildiv Le 7 Starage 164 mY ref L3 8 Tr 166 Apply software filters in eyeline mode In eyeline mode user frequency corrections can be applied to the data to sim ulate a hardware transmission filter The eye diagram analyzer comes with several Bessel Thomson filters These files are on the 71501D memory card Refer toChapter 9 Agilent 70820A User Corrections and Chapter 11 Agi lent 70820A Memory Cards Disks and RAM for information on user correc tions User Correction Files File Name File Data a_bt248832 Ath order Bessel Thomson filter for 2 48832 Gbit sec transmission a_bt_62208 4th order Bessel Thomson filter for 622 08 M bit sec transmission a_bt_ 15552 Ath order Bessel Thomson filter for 155 52 M bit sec transmission 1 9 Note Getting Started Steps for Setting Up Eye Diagram Analysis Three sweep selections are available e single continuous stopped With the continuous selection sweeps occur as soon as the selected triggering conditions are met and repeat continuously as long as the trigger conditions are met The source of the trigger reference is selected using the Setup menu s CH2 softkey The following table shows the reference used when using an Agilent 7084X pattern generator Table 1 1 Trigger Reference of 70841 Eye Mode CLOCK or TRIGGER CLOCK
56. alyzer assigns a prefix according to the type of data Refer to Working with Files on page 3 40 The following list shows the types of data that can be saved as files e Traces Measurement states e Histograms Masks e Limit lines e Calibrations e User corrections e User menus Downloadable programs DLPs Jitter template and calibration files Selecting and Formatting Memory When first turned on the microwave transition analyzer module automatically selects the memory card as the mass storage device You can format memory and save recall erase and list catalog files using the mass storage menu located in the States menu Memory Cards Memory cards must be formatted before use Formatting erases any previ ously stored files and initializes memory for storing data RAM memory cards have a built in battery to retain memory data Data stored in the card remain Note CAUTION Eye Diagram Analyzer Reference Saving to Mass Storage as long as the card s battery has sufficient power You should change the bat tery every two years using the procedure in this section Refer to To Change a Memory Card Battery on page 3 39 RAM memory cards have a write protect switch on the end which is not inserted into the display s card slot If this switch is slid toward the edge of the card marked SAFE no changes may be made to the card s content If you wish to write anew file to a card or re
57. ampling oscilloscope such as the Agi lent 86100A Infiniium DCA The 71501D can perform eye diagram analysis such as extinction ratio testing and mask testing In addition the software allows the system to operate in Agilent E yeline mode In eyeline mode the eye diagram display shows contin uous traces instead of synchronous dots This allows pattern dependent effects to be investigated For example the trace leading to a mask violation can be captured and displayed The eyeline eye diagram can take advantage of trace averaging Therefore very small energy signals can be extracted from broadband noise Finally eye diagrams can be analyzed using software filters Fourth order Bessel T hompson filters can be easily designed for virtually any data rate allowing analysis without having to actually construct a hardware fil ter CAUTION Getting Started Getting Started with the Eye Diagram Analyzer The custom keypad The eye diagram analyzer comes with a custom keypad that snaps into the front panel of 70004A displays The keypad gives you quick access to common instrument functions Each of these functions can also be accessed using the normal softkey menus If you have the custom keypad practice using it You will find that the time required for many of the procedures in this book will be significantly reduced If you need to remove the custom keypad do not pry it out Simply push the tip of a small flat blade screwdriver
58. ata The following program shows how to turn on infinite per sistence Notice how the Param variable is loaded before the Command vari able OUTPUT Mta PROG STR Param INF OUTPUT M ta PROG STR Command PERSIST Use PROG STR to Read Response The 70874A pauses execution after completion of each command This pro vides a mechanism for synchronization between the issuance of a command and the retrieval of a response In your controlling program use the 4 3 Example Programming Commands Introduction PROG WAIT query to indicate when the 70874C has paused Then retrieve the response using the PROG STR query Use PROG STATe to continue pro gram execution Notice the lower case letter e in PROG STATe This indicates the this letter can be entered in either upper or lower case The following example shows how to return the results of eye measurement Notice that the MEAS command does not use the Param variable OUTPUT M ta PROG STR Command M EAS OUTPUT M ta PROG W AIT ENTER M ta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT ALIGN The ALIGN command string automatically aligns a mask to the eye Values of Program Variables Variable Data Type Value Command string ALIGN Param There are no parameters for this command Response string DONE OUTPUT M ta PROG STR Command ALIGN OUTPUT M ta PROG W AIT ENTER M ta A O
59. card is fully inserted into the card slot Switch on the power to all of the equipment Switch on the power to the 70820A last The start up process takes about 6 minutes Do not press any instrument keys until the program is loaded Pressing keys can cause the automatic program loading to abort Getting Started Steps for Setting Up Eye Diagram Analysis If the Program Failed to Load The program has failed to load if one of the following occurs e The message Please wait Loading 70874 never shows The left side softkeys match those shown in the following figure Manually Load the Personality on page 1 17 ca Main Trigger Traces Scale Markers Config a IHHE 9 div page tof 2 70820A Module s Main Menu Manually Load the Personality 1 Insert the 70874A eye diagram memory card into the front panel card slot 2 Display a listing of the files on the memory card by pressing MENU page 1 of 2 States more 1 of 2 mass storage Getting S Steps for Setting Up Eye Diagram Analysis Pulsgen Measure Table Analyze Calib States page cafe tarted msi j HP MS IB t PREV NEXT PAGE Prefix MSI HP MSIB 4 Page 1 LOAD FILE AUTOST ASCII 1288 a_bte4Ba32 ASCII 1536 a_bt_Geebd ASCII 1536 save a bt 15552 ASCII 1536 AP70A71A ASCII dirk tend af catalog W
60. d by pressing ff or U Select the direction to move by pressing move X Y Move the point by rotating the front panel knob or using the numeric keypad Add a Point To add a point select the point to be moved by pressing ff or U Select the closest point counterclockwise from the one that you intend to add Add a point at the location of the currently selected point by pressing ADD POINT A point is inserted between the currently selected point and the next point Select the direction for moving the new point by pressing move X Y Rotate the front panel knob to move the point Delete a Point To delete a point select the point to be moved by pressing ff or U Delete the point by pressing DELETE POINT 11 12 13 14 15 16 17 18 19 20 21 22 Application Tutorials Tutorial 7 Default and Custom M ask or Limit Line Testing Stretch Reduce or Move the Mask To stretch reduce or move the mask by press prev menu scale X Y or offset X Y Add a Mask Margin Press the left side Masks softkey To automatically align the mask to a displayed signal press MASK ALIGN To add mask margins press MASK MARGIN and enter the of needed margin msk mar ON OFF ON prev menu Begin a Test Display the Masks Limits menu by pressing MENU page 1 of 2 Analyze masks limits Select the trace for testing by pressing trace If trace violations are to be counted as errors press count TRC DOT TRC If measurement
61. d data Acquire the data Establish limits for statistical analysis View the mean and standard deviation Histogram data can be acquired once using the SINGLE ACQUIRE softkey or continuously updated using the CONT ACQUIRE softkey Defines a window Tii 1 ns Ti2 1 ns dl 2 ns WINDOW of valid Pulsgen p tj A plej 100 dp iBA HARKERL data samples A 5 WINDOW PARAGE mean 272 343 pa THARKER2 Defines std dev 515 ps 7 data limits fens UPPER for mean LIMIT and ft standard Anat zeH 1c ae deviation Enters Calib loa upper lower 1 haa j limits for calculations States A A A A f A A A f results 5 20B ps div ae ri Cht Displays page 25 m div prev mean and 2of2 44 ref menu standard deviation Horizontal histogram Press other for this additional menu Eye Diagram Analyzer Reference Masks and Limit Lines Masks and Limit Lines Masks and limit lines allow you to test the shape time or frequency versus amplitude of a displayed response Masks are closed polygon shapes Limit lines are lines Traces or measurement points that penetrate a mask or cross a limit line result in testing errors ca Pul sgen histogm masks Measure ae limits Table Analyzef Calib States 1 1 1 1 1 B s CHE pafdiv Tri Cht Mi A page 25 m div dof AV ref Tr 26 Two Masks Displayed on Screen 3 9 Eye Diagram Analyzer Reference Masks and Limit Lines
62. e f a Markers a l eor CLAPEND FMO PI CORR IDFT TINE Noo Config IFFT Fsig FREQ SHIFT RETURN Fear POWER WS page prev Lof ec menu 7 Turn auto scaling on by pressing RETURN format PHASE Scale AUTO SCALE 8 Set the marker by pressing Markers M1 J Continue pressing M1 J until TR3 is shown in the M1 J softkey label 9 Repeatedly press M2 4 until TR3 is shown in the M2 J softkey label Application Tutorials Tutorial 9 Constructing a Low Pass Filter from a Transfer Function 10 Set the marker on 1 86224 GHz using the knob or numeric keypad Main Nett 1 B6624 GHz 124 854 deg DELAY Da TIME a Tringer T DELAY j J Traces mm 1 APERTUR Scale Markers Config T 15 8045 GHz 3 173 GHz diw 5 9252 GHz Trd j kef ek Trd k tk Te page B E 3 div 9B deg div mare of A ref A deg ref cof p 11 Continue by pressing Scale more 1 of 2 AUTO DELAY Traces store trace to user correct adaptiv ON OFF ON 12 Store the filter response in user corrections by pressing CHAN 1 USR COR 13 To view the response or to view the data press Traces select TR2 display ON OFF OFF select TR3 display ON OFF OFF select TR1 input Application Tutorials Tutorial 9 Constructing a Low Pass Filter from a Transfer Function 14 Highlight UCORR1 using the knob Main THA CHi CHL Trigger A ai
63. e lower threshold point on a falling edge of an eye diagram Measure Fast Amplitude and Phase Transitions The 70820A module measures fast amplitude and phase transitions on contin uous wave CW and modulated signals Time frequency and power sweeps can be performed from dc to 40 GHz The 70820A module triggers on the RF input signal During stimulus response measurements the 70820A module controls an RF source instrument s e frequency power pulse modulator Viewing Repetitive and Non Repetitive Signals Because of the sampling techniques employed by the 70820A the 70820A module is optimized for viewing repetitive input signals However there is sin gle shot operation for viewing baseband and modulated non repetitive signals having bandwidths up to 10 MHz Pre trigger data can also be viewed An example of using the single shot operation is measuring the turn on character istics of a pulse modulator Single shot operation uses a maximum sampling rate of 20 MHz 3 5 Eye Diagram Analyzer Reference Performing Eye Diagram M easurements For Optimum Performance The 70820A module should be configured to e Control the RF source over the communications bus Share the same frequency reference as the RF source Channels Versus Traces The 70820A module has two input channels four traces and four trace mem ory registers e Channels are used to measure input signals e Traces are used to display measurement results
64. eps for Setting Up Eye Diagram Analysis 3 The eye diagram is now ready for use To restore the Restore the factory instrument preset by pressing factory MENU page 1 of 2 States more 1 of 2 preset FAC USR FAC instrument preset Getting Started Steps for Setting Up Eye Diagram Analysis Application Tutorials Application Tutorials Application Tutorials Application Tutorials This chapter contains nine tutorials that introduce important eye diagram analyzer features The tutorials should be performed in the order listed To create the data signal you will need a pseudo random binary sequence PRBS pattern generator Refer to Configure the Data Signal on page 2 2 before you start the tutorials You will find the following topics in this chapter Tutorial 1 Measure Eye Parameters 2 4 Tutorial 2 Measure in Optical Power Units 2 8 Tutorial 3 Measure Extinction Ratios on Low Level Signals 2 10 Tutorial 4 Measure Laser Turn on Delay 2 13 Tutorial 5 Use Software Filters 2 15 Tutorial 6 Test to Industry Standards 2 19 Tutorial 7 Default and Custom Mask or Limit Line Testing 2 23 Tutorial 8 Display the Data Pattern 2 27 Tutorial 9 Constructing a Low Pass Filter from a Transfer Function 2 30 Tutorial 10 Create a Vertical Histogram 2 36 Tutorial 11 Create a Horizontal Histogram 2 41 Configure the Data Signal The following list shows typical settings that can be used for the data signal The list assum
65. er use This sec tion shows you how to accomplish this task using the 70820A module s mass storage menu You can also save recall and erase user correction files using the eye diagram analyzer s Mass Storage menu The files are saved to default memory To select default memory refer to Selecting and Formatting Memory on page 3 34 Each file has a file name that consists of the prefix a_ followed by a custom name that you enter The prefix identifies the file as user correction data Entering file names is made much easier if you have an 46021A keyboard and keyboard cable Display the Mass Storage menu by pressing MENU page 1 of 2 States more 1 of 2 mass storage If the mass storage device needs to be selected refer to Selecting and For matting Memory on page 3 34 Save the user correction file by pressing save SAVE USR COR Entering a File Name without a Keyboard a Turn the front panel knob to move the character select cursor b Press SELECT CHAR to enter a character at the character select cursor c Press the numeric keypad to enter numbers or a minus sign d The INSERT or softkey determines the action of the SELECT CHAR soft key Choices are INSERT a character REPLACE an existing character or DELETE a character e Press the and keys beneath the front panel knob to move the com mand entry cursor f Use the CLEAR TO END softkey to remove characters from the command entry cursor to the end of
66. erence Agilent 70820A User Corrections DELETE ALL DELETE FREQ de value 1H8 8484 GHz PHASE 4B deg A A deg pa nex h to FREQ s ope slope LOG LIN copy ta CH2 prev menu The following two figures show the effect of selecting linear slope and flat types The trace graphically shows the filter With the exception of the path to next FREQ field the data in each filter is identical Pulsgen Measure Table Analyze Calib States page 2af P l cht che Pre usr cor F EES SEL EDT path to FREQ MAGN PHASE next FREQ SLOPE FLAT de value EELEE 4B deg slope 1 966240 GHz 3 BL dB Q 48 deg slope INSERT 2 458320 GHz 5 71 dB 48 deg slope LINE 4 976640 GHz 21 58 dB 48 deg slope BG B08 GHz 21 58 dB 48 deg ather prey menu 3 53 Eye Diagram Analyzer Reference Agilent 70820A User Corrections Pulsgen EHLICHE i r i usr cor Measure ONJ OFF Table t SEL EDT path to aavliee FREQ MAGN PHASE next FREQ ECE de value B BA dE 4B deg lat 1 966240 GHz 3 61 dB 48 deg lat INSERT Galib 2 4B9320 GHz 5 71 dB A B deg flat LINE 4 976640 GHz 21 54 dB 4 48 deg 1BA ABAB GHz 21 58 dB 4 48 deg States ather page prev date menu To Enter a Line of Data
67. eries of screens from which to select the following The pattern generator used e The source of the 10 MHz frequency reference Getting Started Steps for Setting Up Eye Diagram Analysis Note When used with an 71612A 70843 the system requires a manual configuration Set Up the Select from eye eyeline and pattern modes Measurement Use the Setup menu s diagram softkey to select from one of three measure Conditions ment modes eye eyeline and pattern Setup menu Ps Setup Trg Cal Traces Measure Narkers Press to select eye eyeline diagram EYE READ NPAT GEN jeh is CLK OUT eit ATNTUL sag DELAY eyef ltr or pattern modes ais De TRIES pardiy NIOFF Nass Mi adi CLEAR Storage 4B m ref Tres DISPLAY Features Available in Each Mode Eye Mode Eyeline Mode Pattern Mode Eye M easurements X Extinction Ratio Measurements X X Mask Testing X X X Display the M ask Error Trace X X Improve Sensitivity Using Eye Filtering X X 40 GHz Extended Bandwidth X X User Corrections X X Display Data Pattern X 1 5 Getting Started Steps for Setting Up Eye Diagram Analysis Eye Mode The eye mode displays traces using individual dots in a manner that is similar to conventional sampling oscilloscopes Use this mode for the following e Typical eye diagram measurements e Extinction ratio measurements Tri Cht gH mvfdiv 244 mW ref Getting Started Steps for Set
68. es measure markers masks and mass storage menus 3 13 traces measure markers masks storage 3 13 user correction 3 51 mode selection 1 22 modes features 1 5 monochrome grading persistence 3 29 monochrome persistence 3 28 move the measurement plane 1 26 number of bits displayed 3 16 0 offset calibration 2 5 optical power units 3 16 optical power units display 3 16 optical power units measurement 2 8 optimum performance 3 6 outline setting up eye diagram 1 4 overshoot resulting from laser bias 2 5 P pass fail testing 1 8 pattern display 2 27 pattern generator settings 1 23 pattern generator 70841A B 1 24 pattern mode 1 8 pattern modes 1 5 performing self test 3 69 PERSIST command 4 11 persistence modes 3 27 personality loading 1 16 plotting 3 48 position and scale each trace 3 26 preset state 1 26 preview programming commands 3 20 Index 4 printing 3 47 PROG STR to read response 4 3 program failed to load 1 17 program variables values 4 5 programming commands 4 2 programming commands preview 3 20 QUIT command 4 12 R RAM disks 3 35 read response PROG STR 4 3 rear panel connections 1 13 recall files 3 43 recall mask or limit line 3 46 recall user correction file 3 60 reference 10 MHz 1 11 reference eye diagram analyzer 3 2 repetitive and non repetitive signals 3 5 restore the factory instrument preset 1 27 return to the jitter a
69. es on three sweeps cJ trace e a a F Jdisplay Measure f ON OFF test Table JONI OFF Tend on isles JHERRORS x j 4count Calib TRC DOT h 4 F def ine States aT 1 shapes Tra Cht page iB dB div prev 2 af 1 dem ref Tr d menu Eye Diagram Analyzer Reference Eye Diagram Menu Maps Eye Diagram Menu Maps The two menu maps in this section graphically represent the eye diagram ana lyzer s softkey menus EYE Main Menu EYELINE Left Side Softkeys PATTERN diagram _________ Setup READ PAT GEN Trg Cal CH2 IS Traces BIT INTVL prey menu Measure DELAY Markers eyefltr ONIOFF Masks CLEAR DISPLAY CLOCK RATE Mass Storage CLOCK DIVISOR PATTERN LENGTH 2 n 1 ONIOFF PAT TRG FACTOR prey menu SINGLE CONT STOP CLK OUT LEVEL TRG OUT CH EXT ATTEN CH2 EXT ATTEN OFFSET CAL more 1 of 2 prey menu usr cor ONIOFF AUTO extd BW ONIOFF EXT autorng ONIOFF INT IP REF DEFINE USER IP CODE VERSION more 2 of 2 prey menu Some of the keys in this menu may appear depending on the menut pattern generator and clock source configuration Setup and Trg Cal M enus Eye Diagram Analyzer Reference Eye Diagram Menu Maps Main Menu Left Side Softkeys Setup select INFINIT Trg Cal display ONIOFF VARIABLE Traces SCALE COLOR GRADING Measure REF LEVIPOS MONO GRADING Markers AUTO SCALE PERSIST SWE
70. es you are using an 70841A B pattern generator The exact set tings depend upon the system you are using If the system includes an 70841A B pattern generator use the pattern generator s status screen to enter these values The procedure for viewing the status screen is explained in Controlling an 70841A B Pattern Generator on page 1 24 e In the select pattern menu Pattern PRBS 2 7 1 In the dat o p err add menu Data Ampl typically 800 mV to 2 V depending on laser Data Hi Lvl 0 V depending on laser e Inthe trg o p clk o p menu Application Tutorials Application Tutorials Clock Freq 2 48832 GHz Clock Ampl 500 mV Clock Hi Lvl 0 V If you re performing these tutorials without the laser source and optical to electrical converter reduce the level of the data signal as shown in the follow ing settings Data Ampl 250 mV e Data Hi Lvl 300 mV 2 3 Application Tutorials Tutorial 1 Measure Eye Parameters Tutorial 1 Measure E ye Parameters The eye diagram analyzer performs automatic eye measurements in eye mode This mode is similar to that of conventional sampling oscilloscopes the display shows individual dots View the Signal To view the signal press INSTR PRESET Traces persist VARIABL This turns the persistence mode on Refer to Chapter 3 Eye Diagram Ana lyzer Reference for an explanation of the available persistence modes Enter the number of sweeps by pressing PERSIST
71. esponse of optical to electrical converters To create and use your own user corrections enter the User Correction menu This menu is located under the 70820A s Calib menu The microwave transi tion analyzer maintains two separate user correction memories one for chan nel 1 and one for channel 2 After entering the User Correction menu the microwave transition analyzer displays user correction data in the lower half of the screen The screen s upper half remains dedicated to showing the nor mal display Or if the displayed trace is assigned to the data the trace shows a graphical representation of the filter as the following figure shows To learn how to assign a trace to user corrections refer to Viewing User Correction Data on page 3 56 Eye Diagram Analyzer Reference Agilent 70820A User Corrections Pulsgen Measure Table Analyze Calib States page cafe Example User Corrections User corrections always contain at least two default lines of data as shown in the following figure While these two lines of data cannot be removed you can modify their magnitude or phase values New lines of data are easily added Each line of data consists of FRE Quency MAGNitude PHASE and path to next FREQ fields The path to next FREQ field determines how data is inter polated between two adjacent user correction frequency points The path to the
72. ess Statistical results ca VOL 189 mY Vipj 401 mY dU 2B4 my Pulsgen pti OX ple 100 dp 8 MEAN Measure nean 5 B uy 10 DEV p std dev 63 mV Table Analyze F OFF Calib States 1 f f L Bs GH pavdiv Tri Cht page 4A m div prey dof 2 8V ref menu Line indicating mean value Application Tutorials Tutorial 11 Create a Horizontal Histogram Tutorial 11 Create a Horizontal Histogram This tutorial creates a horizontal histogram on data taken from a sine wave The procedure however works for any type of waveform Select the Histogram Type Display a trace to perform statistical analysis on Display the histogram menu by pressing page 1 of 2 Analyze histogm Select the trace to perform the statistical analysis on by pressing trace Use the knob to select the desired trace Select the Vertical Histogram function by pressing histog HORZNTL HISTOGM_ HORZNTL HISTOGM Acquire the Data Define the window for taking histogram data by pressing other WINDOW MARKER1 WINDOW MARKER2 Notice the values of the marker positions are indicated at the top of the dis play Application Tutorials Tutorial 11 Create a Horizontal Histogram Window marker 2 tf oA YU 5 QBE 9 21 B1 JE 3 dY 55 3E 3 TROON pdp ee Aa MARKER 1 marker 1 Tinian Measure ota mV MARKERE UPPE TEIN Table a Analyze f y Calib f LONER Jein 4LIMIT Ax 188
73. eys to turn user corrections on and off by pressing USER Trg Cal more 1 of 2 usr cor ON OFF To Delete a Channel s User Corrections Eye Diagram Analyzer Reference Agilent 70820A User Corrections Delete a channel s user corrections by pressing MENU page 1 of 2 Calib user corr Select the desired channel by pressing CH1 CH2 Delete the selected channels user corrections by pressing other DELETE ALL To delete all corrections press CONFIRM DEL ALL To cancel the deletion process press ABORT DEL ALL Entering and Editing User Corrections The User Correction menu provides softkeys for entering and editing lines of user correction data To view user correction data graphically at the same time it is created refer to Viewing User Correction Data on page 3 56 The SEL EDT softkey determines whether the front panel knob and arrow keys select a field for editing the current field s data New lines can be entered between the first and last lines Refer to To enter a line of data in this sec tion The microwave transition analyzer interpolates the data between adjacent points Interpolation between the defined points can be either slope or flat line If slope is selected the slope LOGILIN softkey determines whether slopes are linear or logarithmic To locate this softkey press other in the User Correction menu Pulsgen Measure Table Analyze Calib States page cafe Eye Diagram Analyzer Ref
74. fault mask for OC 3 OC 12 default mask for OC 12 OC 48 default mask for OC 48 Values of Program Variables Variable Data Type Value Command string DEFAULT string STM 1 STM 4 Param STM 16 0C 3 OC 12 0C 48 Response string DONE OUTPUT M ta PROG STR Param STM 4 OUTPUT M ta PROG STR Command DEFAULT OUTPUT M ta PROG W AIT ENTER M ta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT Example Programming Commands Introduction DELAY The DELAY command string sets the displayed delay value to the number of bits specified in the Param variable Values of Program Variables Variable Data Type Value Command string DELAY Param floating point number example 2 75 Response string DONE OUTPUT M ta PROG NUM B Param 2 75 OUTPUT M ta PROG STR Command DELAY OUTPUT M ta PROG W AIT ENTER Mta A OUTPUT M ta PROG STR Response ENTER M ta Response OUTPUT M ta PROG STAT CONT DIAGRAM The DIAGRAM command string sets the diagram display to one of the follow ing types specified in the Param variable EYE displays eye pattern This is the standard display shown on digitizing oscilloscopes EYELINE displays a continuous line which shows the actual data value for the bit period PATTERN displays a continuous line like EYELINE but for pattern trigger mode 4 7 Programming Commands Introduction
75. g 2 23 custom prefix 3 45 D data pattern display 2 27 data signal configuration 2 2 data user corrections 3 20 date and time viewing 3 21 date code of firmware 3 20 dc offset compensation 3 23 default and custom mask or limit line testing 2 23 DEFAULT command 4 6 definition INSTR PRESET key 1 11 definitions 0 level 3 4 1 level 3 4 crossing level 3 5 extinction ratio 3 4 eye height 3 4 eye jitter 3 5 eye width 3 5 mean fall time 3 5 mean rise time 3 5 measurements 3 4 delay a channel 3 64 delay addition 2 28 delay between channels matching 3 63 DELAY command 4 7 delete a line of data 3 55 description eye diagram measurements 3 3 masks and limit lines 3 9 setup and trg cal menu 3 12 DIAGRAM command 4 7 disk GPIB 3 37 internal RAM 3 37 display copy 3 47 traces 3 25 display control 3 16 display the data pattern 2 27 display trace errors 2 21 display traces 3 25 display number of bits 3 16 display plot 3 48 displaying traces 3 25 duplicate memory card 3 41 E edit a line of data 3 55 edit mask or limit line 2 24 enter a line of data 3 54 entering and editing user corrections 3 52 erase files 3 43 erase mask or limit line 3 46 erase user correction file 3 60 errors stop on and display trace 2 21 example 70841A B status screen 1 24 autoscaled display of low level signal 2 11 display of user error in pattern mode 2 29 extinction ratio measurement
76. ge Initializing formatting a memory card The following steps erase any files stored on the card If the memory card is new and needs to be formatted press MENU page 1 of 2 States more 1 of 2 mass storage more FORMAT To use the LIF format press FORMAT as LIF To format as DOS press FORMAT as DOS To invoke Instrument BASIC press USER If the eye diagram personality is loaded press USER again Enter an INITIALIZE statement to create a RAM disk For example enter the following BASIC statement INITIALIZE MEMORY 0 0 128 Select the internal RAM disk by pressing MENU page 1 of 2 States more 1 of 2 mass storage msi MEMORY The RAM disk number is shown on the screen Use the front panel knob to change the RAM disk number Connect the GPIB disk drive to the 70004A color display using an GPIB cable Determine or set the GPIB address of the disk drive Refer to the disk drive s user s manual for information on determining the disk drive s address Set the GPIB address of the disk drive by pressing DISPLAY Mass Storage msi GPIB disk GPIB ADDRESS enter the address of the disk drive This value is between 1 and 7 Eye Diagram Analyzer Reference Saving to Mass Storage Enter the disk drive s unit number by pressing UNIT NUMBER This number is typically a 0 or 1 Zero usually indicates the disk drive s left side slot Enter the disk drive s volume number by pressing VOLUM
77. generator modules with your eye diagram analyzer connect cables to the instruments as shown in the following graphic e If you are using a clock source other than an 70311A make sure that the signal generator and 70820A microwave transition analyzer module share the same frequency reference Usethe 10 MHz REF connectors on the rear panel of the 70820A 10 MHz Ref Out GP MSIB Out GP MSIB In Ext Ref Input crs oki er pe GP MSIB GP MSIB pobGa In Out Rear Panel Cable Connections 3 Connect the front panel cables as shown in the figure on the following page Use an adapter between the cables and channel connectors The data signal connects to the 70820A s RF INPUT 1 connector The trigger or clock signal connects to the 70820A s RF INPUT 2 connector Getting Started Steps for Setting Up Eye Diagram Analysis Channel 1 ooo oo0 Sooq Ocog Clock Out 6 dB ATTENUATOR Front Panel Cable Connections Cables SMA to SMA Channel 1 p n 8120 4948 SMA to SMA Channel 2 p n 8120 4948 SMB to SMB 10 MHz Reference p n 8120 5025 Miscellaneous 3 5 mm f to 2 4 mm f two p n 1250 2277 6 dB attenuator 8493C 4 Ifthe attenuator connected to the 70820A s RF INPUT 2 connector is not 6 dB press Trg Cal CH2 EXT ATTEN then enter the value of the attenuator Getting Started Steps for Setting Up Eye Diagram Analysis Laser and
78. gin Errors for the specifications with the specified amount of margin show up beside the M4 L5 and L6 screen annotations The eye diagram analyzer can count dot trace point errors instead of trace errors Use the count TRC DOT softkey to make the selection If a given error puts 12 trace points within the mask then the error counter increments by 12 This is useful for determining the extent of any given error These features can be used with either eye or eyeline modes 10 11 12 Application Tutorials Tutorial 6 Test to Industry Standards default Setup masks Mask Margin aie 15 E isplay Travel ae AON OFF T MASK races ALIGN HASK Measure HARGIN te msk mar Markers ONJ OFF tasks NSIS 124 452 ps AB cde ps div Tri Cht M1 A M4 A Mass 5B mW div era L5 4 prev Storage LBA mY ref L3 A Lo A Tr JE menu Stop on and Display Trace Errors The eye diagram analyzer has the ability to stop data acquisition when a mask violation occurs The number of traces or errors that stop this data acquisition can be specified In addition if you are in eyeline mode you can separately display the traces that have caused an error Set the bit interval and delay by pressing Setup BIT INTVL and enter 1 DELAY and enter 3 The mask will be offset to the right side of the display Set the analyzer so testing will stop after two errors have occurred by pressing Errors ON
79. gram analyzer automatically selects the appropriate hardware gain and offset to maximize the signal at the analog to digital converter regardless of the input signal s amplitude Selecting the 10 MHz reference on Instrument Preset Use the Trg Cal menu s IP REF softkey to select the source of the 10 MHz ref erence on an INSTR PRESET Choices are internal external or auto With auto the eye diagram automatically selects an external reference if it is present at the 70820A s rear panel connector Otherwise the module s inter nal reference is selected Redefining the INSTR PRESET key The Trg Cal menu s DEFINE USER IP softkey redefines the settings invoked by the INSTR PRESET key Redefining the instrument preset can save valu able time when configuring for measurements Getting Started Steps for Setting Up Eye Diagram Analysis Step 1 Connect the Equipment 70841A B Pattern Generator and 70311A Signal Generator Modules 1 If you are using 70841A B pattern generator and 70311A signal generator modules with your eye diagram analyzer install them into an MMS mainframe as shown in the following figure Microwave Display Transition Analyzer Personality Card K x Display Pattern Clock Generator Source pale Getting Started Steps for Setting Up Eye Diagram Analysis 2 If you are using 70841A B pattern generator and 70311A signal
80. hannel 1 Measure Signal Parameters To include the rise time and fall time measurement in the displayed results press Measure r f tim ON OFF ON Application Tutorials Tutorial 1 Measure Eye Parameters Enabling this function approximately doubles the measurement time 8 Perform the eye measurement by pressing MEASURE EYE After a brief period of time the display should look like the following figure Refer to Chapter 3 Eye Diagram Analyzer Reference for definitions of each measurement listed on the screen Setup Trg Cal Traces Measure Markers Masks Mass Storage Eye Height Crossing Level Eye Width Eye Jitter tol Mean Rise Time Mean Fall Time 1 Level mean ol A Level mean al 259 07 ef faa 164 92 127 JB 291 84 15 B16 41 414 74 B66 11 79 3 4734 72 963 43 841 fab dB M385 1843 my my x x Bit Bit Bit Bit Interval Interval Interval Interval Example Eye Measurements Measure Extinction Ratio 9 Measure the extinction ratio by pressing EXTINCT RATIO The results are added to the displayed list of measurement results oa mi ex oa a a m era Application Tutorials Tutorial 1 Measure Eye Parameters Set up Trg Cal Extinction ratio measurement Traces iy PO pg hs PERNT if OFF results a ee i til 5 UPPER
81. horizontal time scale automatically changes to the appropriate setting Use DELAY to enter time delay The amount of delay is entered in bits Use this feature in pattern mode to view different portions of the PRBS waveform The amount of delay can be as much as 1000 times the time span In addition the eye diagram analyzer can view the trace before the trigger event Negative time delay up to time span jover2 can be entered Set the number of bits displayed by pressing Setup BIT INTVL and enter the number of bits to display Set the time delay by pressing Setup DELAY and enter the desired time delay The Trg Cal menu s CH1 EXT ATTEN and CH2 EXT ATTEN softkeys allow you to specify any external attenuation or optical to electrical responsivity conversion between the source and input channels Specifying an attenuation on channel 1 changes the measurement plane from the front panel channel 1 connector to include the indicated attenuation Specifying an optical to elec trical responsivity displays optical units referenced to the input of the optical to electrical converter Channel and marker readouts change to watts div Also the CH1 EXT ATTEN softkey changes to read CH1 RSPVTY responsiv ity To measure the optical power press Trg Cal CH1 EXT ATTEN and enter the responsivity value in watts div Notice the CH1 EXT ATTEN softkey changes to read CH1 RSPVTY respon sivity To Improve the Sensitivity in Eyeline Mode
82. ications Time scale range 5 ps div 100 s div full sclae is 10 divsions Delta time measurement accuracy j y 1 psor lt timespan number of trace points whichever is larger Time delay in eye mode timespan clock frequencies gt 10 M Hz 2 to 1000 time span Time delay in eyeline and pattern modes Pattern repetition frequeny gt 10 M Hz _times p query A E to 1000 time span Pattern repetition frequency lt 10 M Hz 2 pattern repetition lengths Time delay between channels lt 10 ps a Time delay between channels up to 20 of the time span is correctable in software 5 7 Specifications and Characteristics Declaration of Conformity Declaration of Conformity DECLARATION OF CONFORMITY according to ISO IEC Guide 22 and EN 45014 Manufacturer s Name Manufacturer s Address Microwave Instruments Division 1400 Fountaingrove Parkway Santa Rosa CA 95403 1799 USA declares that the product Product Name Microwave Transition Analyzer Model Number HP 71500A HP 70820A Product Options This declaration covers all options of the above products conforms to the following Product specifications Safety IEC 348 1978 HD 401 1 1981 CAN CSA C22 2 No 231 Series M 89 EMC CISPR 11 1990 EN 55011 1991 Group 1 Class A IEC 801 2 1984 EN 50082 1 1992 4 kV CD 8 kV AD IEC 801 3 1984 EN 50082 1 1992 3 V m 27 500 MHz IEC 801 4 1988 EN 50082 1 1992 0 5 kV Sig Lines 1 kV Power Lines IEC 555 2
83. ily reproduce copies without having to copy the files one at a time Use the following steps Refer to To Use a Memory Card on page 3 36 to select the memory card for use Insert the memory card with the files into the front panel card slot Press USER If the eye diagram analyzer personality is loaded press USER twice Use a keyboard to enter the following Instrument BASIC commands These commands initialize a RAM disk and copy the files from the card to the RAM disk If you don t have a keyboard Instrument BASIC has an editor for creating these commands INITIALIZE MEMORY 0 0 WILDCARDS DOS COPY TO MEMORY 0 0 Remove the card from the card slot and insert a blank formatted card in the slot To Catalog all Files To Save a File Eye Diagram Analyzer Reference Saving to Mass Storage Issue the following Instrument BASIC command to copy the files from the RAM disk to the new card COPY MEMORY 0 0 TO EXTERNAL 904 Use this procedure to catalog default memory To select default memory refer to Selecting and Formatting Memory on page 3 34 If you plan to catalog the files on a memory card insert the card in the front panel card slot Display a catalog of the files by pressing MENU page 1 of 2 States more 1 of 2 mass storage Remember to insert the card before cataloging a memory card If the message 6218 catalog open failed is displayed the card is missing The HP MSIB address
84. iv Turn off Tri Chi monochrome Mass 2B mV div prev Starage 4B mY ref Tr 7 menu persistence The Persistence Submenu Infinite Monochrome Persistence With infinite monochrome persistence INFINIT traces accumulate on the display until persistence is turned off or the display is cleared using the Setup menu s CLEAR DISPLAY softkey Press OFF to turn off infinite monochrome persistence Variable Monochrome Persistence With variable monochrome persistence VARIABL older traces become dim mer as new traces are acquired Traces can be one of seven different bright ness levels with new traces being the brightest After N number of sweeps N is set with the PERSIST SWEEPS every trace gets dimmer by one intensity level traces already at the dimmest level disappear altogether Lower values of N work best with this type of persistence typically values of five through 10 Press OFF to turn off this persistence Color Grading Persistence With color grading persistence COLOR GRADING the color of a displayed pixel is a function of how many times a trace dot falls on that particular pixel There are five possible colors that a pixel can be If a pixel has progressed to the highest color yellow before N PERSIST SWEEPS have occurred it remains that color no matter how many more dots fall on it After N PERSIST SWEEPS the color grading acquisition stops The following list shows the order of colors a pixel can progress through
85. k frequency or a pattern trigger be sure to set CH2 is to TRG OUT If a signal generator other than the 70311A is used enter the precise clock frequency by pressing prev menu CLOCK RATE and enter the clock rate Controlling an 70841A B Pattern Generator Note Getting Started Steps for Setting Up Eye Diagram Analysis When using the 70311A clock source below 3 Gb s This section explains how to display the menus for the 70841A B pattern gen erator The display can be assigned to control either the eye diagram analyzer or the 70841A B pattern generator If the eye diagram analyzer is configured with a non 70841 pattern generator you must manually set the trigger level Refer to To Manually Set the Trigger Level on page 1 25 in this chapter 1 Turn on the power for both mainframes Wait until the start up routines are completed and the mainframes are ready for key presses Continue by pressing DISPLAY NEXT INSTR If several instruments are in the system you may have to press NEXT INSTR several times Ifthe 70841A B s status screen shown in the following figure is not shown the pattern generator is probably addressed as a slave instead of a master Perform the following steps a Press the left side Address Map softkey LT select HP 7 841B PATTERN GENERATOR Status 8 45 POLRITY pattern Data Normal NORMINY edit DATA usr pat Pattern PRBS 247 ECL Trigger Pattern 8800000 dat_o DATA cE
86. lay on channel 2 ta RF carr POET A a NA Juser Measure 4 corr Jehan sken Table Analyze mee Calth eee teal s signal States Tri Chi Tre Che page OB m div SB m div caf 2 GY ref QW ref Trace 2 delayed relative to trace 1 Use the AUTO SKEW softkey to automatically compensate the delay on chan nel 2 Automatic skewing assumes two equal phase signals input to channels 1 and 2 If measurements are to be performed at multiple frequencies it is rec ommended that the AUTO SKEW function be performed first at a low fre quency and then at higher frequencies to ensure better resolution Delay can be manually compensated using the CHAN2 SKEW softkey F or convenience the SEC DIV softkey is provided so that the time scale can be changed Eye Diagram Analyzer Reference Agilent 70820A Calibration Added delay ra Pulsgen AUTO SKEW Measure Tsecvory Table Analyze Calib States te BEB pavdiv Trt Cht Tre Che page OB mVfdiv SB mi div prey dof 2 GY ref QW ref menu Trace 2 Delay Compensated To Delaya Automatically compensate channel 2 by pressing enannel MENU page 1 of 2 Calib chan skew AUTO SKEW Calibrating the IF The microwave transition analyzer module provides separate automatic IF cal ibration routines for channel 1 and channel 2 Each requires approximately 30 minutes to run For optimum performance you should perform the calibra tions when at lea
87. lication Tutorials Tutorial 10 Create a Vertical Histogram Tutorial 10 Create a Vertical Histogram This tutorial creates a vertical histogram on data taken from a sine wave The procedure however works for any type of waveform Select the Histogram Type Display a trace to perform statistical analysis on Display the histogram menu by pressing page 1 of 2 Analyze histogm Select the trace to perform the statistical analysis on by pressing trace Use the knob to select the desired trace Select the Vertical Histogram function by pressing histog VERTICL HISTOGMVERTICL HISTOGM Acquire the Data Define the window for taking histogram data by pressing other WINDOW MARKER1 WINDOW MARKER2 Notice the values of the marker positions are indicated at the top of the dis play Window marker 1 amp 4 X Ld A KiR B Pulsgen d amp Window marker 2 marker Measure 489 281 ps Table f Analyze Calib States Tri Chi page 4B m div cof 2 Y ref BAB pa div Application Tutorials Tutorial 10 Create a Vertical Histogram WINDOW MARKERI pH NODON HARKERe UPPER YLIMIT LOWER 4LIMNIT 4LIMIT 4 188 results prey menu 6 Enter the number of samples to be taken for the histogram by pressing prev menu NUMBER SAMPLES of samples ENTER The default number of samples taken is 1000 7 To draw the vertical histogram press SINGLE
88. mes referred to as the dark level The offset calibration ensures accurate measurements of the laser s level Turn the laser off If you are measuring the pattern generator directly disconnect the input signal at channel 1 Perform the calibration by pressing Trg Cal OFFSET CAL CONT The calibration takes about a minute to execute When the calibration is finished DC NULL done is displayed Turn the laser on If you are measuring the pattern generator directly reconnect the input signal at channel 1 Application Tutorials Tutorial 3 Measure Extinction Ratios on Low Level Signals Measure the E xtinction Ratio 8 To measure the extinction ratio press Measure NUMBER SAMPLES and enter 20000 EXTINCT RATIO Refer to the following figure sep ae Trg Cal HERS ise i Measure Extinction Ratia 5 BEB 7 534 dB TE porter wi asks SRHPLES 7 i g OFF Extinction Ratio Measurement on a Low Level Signal with Eye Filtering On Display the Signal in Optical Units 9 To display the signal in optical units press Trg Cal CH1 EXT ATTEN and enter 30 V Watt Application Tutorials Tutorial 4 Measure Laser Turn on Delay Tutorial 4 Measure Laser Turn on Delay On screen markers can be used to measure both amplitude and time separa tion in eye diagrams The compatible modes for markers are eye eyeline and pattern Change to E yeline
89. more Apply the filter data to the traces by pressing Trg Cal more 1 of 2 usr cor ON OFF ON Application Tutorials Tutorial 5 Use Software Filters 7 Turn the autoscale function on by pressing Traces AUTO SCALE The display should look like the following figure Notice that the laser overshoot is no longer visible due to the filtering effect of the user corrections in the 71501A Setup Trg Cal Traces Measure Markers Masks Nass Storage a B s 100 465 psfdiv Tri Chi oH mYdiv LEA m ref Example Filtered Laser Overshoot select TRA display ON OFF SCALE REF LEW POS AUTO SCALE persist average Application Tutorials Tutorial 6 Test to Industry Standards Tutorial 6 Test to Industry Standards Masks allow you to test eye diagrams against industry standards The eye dia gram analyzer provides built in masks for testing the major SONET SDH transmission rates Compatible modes are eye and eyeline Shown in this tuto rial is the ability to e Count mask errors Allow for specified amount of margin testing Stop after a specified number of trace errors e Show the violation trace eyeline mode only Select the Mask Set the analyzer to a known state by pressing INSTR PRESET You can use your own hardware filter during this tutorial or load a software filter as described in the previous tutorial
90. most installations press CONT To manually enter the HP MSIB address use the displayed softkeys RECNF IG ye diagram analyzer is correctly configured with its pattern generator If you would like to reconfigure your eye diagram analyzer system press RECNFIG Otherwise press CONT Current source HP7B84X Example of a Configuration Previously Done Getting Started Steps for Setting Up Eye Diagram Analysis HP 7 B4X To configure the eye diagram analyzer with its pattern generator please choose one of the following HP7 84X If you have an HP pattern generator select this one MANUAL if you do not have an HP pattern generator select this one You pill be required to manually enter the clock frequency and the pattern length instal5 First Self Guided Screen HP MSIB The address of the pattern generator must be selected unless it is slaved to an error detector In that case the address of the error detector must be selected 70841B PATT GEN at row B column 42 Otherwise manually enter the ROW and COLUMN address before pressing CONT instal2 3 Use the following self guided screen to indicate the 10 MHz frequency reference used Press INTERNL if the 70820A module is used as the reference Press EXTERNL if the clock source is used as the reference Getting Started Steps for Setting Up Eye Diagram Analysis INTERNL RS SS a E a a a a The 0 MHz reference must be configured properly
91. move a file slide its write protect switch toward the center of the card If no card is inserted in the front panel card slot and you attempt to catalog a memory card the display shows the message catalog open failed Place a card in the card slot and retry the operation RAM Disks RAM disks offer a convenient method of duplicating memory cards Refer to To Duplicate a Memory Card on page 3 41 Up to 16 internal RAM disks can be created These are numbered 0 through 15 The default size of each RAM disk is 32 kilobytes Use Instrument BASIC s INITIALIZE statement to create each disk The fol lowing example creates RAM disk zero INITIALIZE MEMORY 0 0 128 The second integer 0 determines the RAM disk number The value 128 repre sents the size of the RAM disk in sectors Each sector consists of 256 bytes So a value of 128 sectors creates a RAM disk of 32 kilobytes A value of 512 sectors creates a RAM disk of 128 kilobytes Use the following command to create RAM disk 1 with a size of 128 kilobytes INITIALIZE MEMORY 0 1 512 Because internal RAM is volatile all RAM disks are deleted when the power is turned off When this happens all files are lost and each RAM disk must be recreated To Use a Memory Card Eye Diagram Analyzer Reference Saving to Mass Storage GPIB Disk Drives Measurement data and files can be saved on an external GPIB disk drive The disk drive must be a 3 5
92. n SHON a peepee COR FFT stage Measure f f Hok JCR FIR a SHOW Table SICAL iai UUAA TcHL CAL pees INFO l Jene caL Calib TinFo States i 1 f 1 f f 1 1 a Hz 15 kHr div 154 kHz Trt Cht Tr2 Che page dB div a dB div prey caf 2 1 6 dB ref 1 6 dB ref menu Channel 2 data To View Calibration Data 1 Display the Traces menu by pressing MENU Traces 2 To make viewing the calibration date easier turn all displayed traces off by pressing select display ON OFF OFF 3 Display the Calibration menu by pressing page 1 of 2 Calib 4 To view the data press IF calib cal debug show Eye Diagram Analyzer Reference Agilent 70820A Calibration 5 To view the data for channel 1 press CH1 CAL INFO 6 To view the data for channel 2 press CH2 CAL INFO 7 To view additional pages of information continue pressing CH1 CAL INFO or CH2 CAL INFO Performing a Self Test You can initiate an automatic self test routine that checks the internal condi tion of all major circuits The self test takes approximately 30 seconds to run This routine automatically runs whenever the microwave transition analyzer is turned on Perform the self test by pressing MENU page 1 of 2 Calib SELF TEST Controlling the Calibrator Signal For verification purposes the Calibrator Output signal can be manually con trolled This includes changing its amplitude and frequency The signal has the following characteristics Shape s
93. nalyzer or eye diagram analyzer 3 20 RF correction on off 3 62 S safety information 1 iii save instrument state as preset state 1 26 save files 3 42 save instrument state 3 45 save mask or limit line 3 46 saving mass storage 3 34 user correction file 3 59 saving recalling cataloging user correction files 3 59 scale and position each trace 3 26 scale trace 3 26 screen instructions 1 19 select single or continuous sweeps 1 22 select the mode 1 22 select the pattern generator settings 1 23 Index select trigger source 1 22 selecting memory 3 34 self guided screen 1 20 self test 3 69 sensitivity in eyeline mode 3 17 set up measurement conditions 1 22 setting up eye diagram analysis 1 4 setup and trg cal 3 12 signals repetitive and non repetitive 3 5 softkeys left side menu 3 15 software filter loading 2 17 software filters 1 9 software filters using 2 15 standards testing 2 19 statistical analysis 2 38 2 43 stop on and display trace errors 2 21 storage GPIB disk 3 37 storage internal RAM 3 37 sweep selection 1 22 sweeps available 1 10 T test to industry standards 2 19 testing responses 3 11 testing mask or limit line 2 23 testing with additional margin 2 20 time and date viewing 3 21 time delay addition 2 28 trace average 3 26 trace 2 delay compensated 3 64 trace averaging 3 26 trace errors 2 21 trace error 3 32 trace persistence 3 27
94. nce Performing Eye Diagram Measurements 3 3 Generating Histograms 3 7 Masks and Limit Lines 3 9 Eye Diagram Menu Maps 3 12 Agilent 70820A Menus 3 14 Controlling the Display 3 16 Calibrating the Eye Diagram Analyzer 3 23 Displaying Traces 3 25 Using Markers 3 30 Applying Mask Testing 3 31 Saving to Mass Storage 3 34 Creating Copies of the Display 3 47 Agilent 70820A User Corrections 3 49 Agilent 70820A Calibration 3 61 4 Programming Commands Introduction 4 3 Contents 1 Contents Specifications and Characteristics Vertical Specifications 5 3 Input Channel Specifications 5 4 Trigger Specifications 5 5 Trigger Specifications 5 6 Horizontal Specifications 5 7 Declaration of Conformity 5 8 Contents 2 Getting Started Getting Started Getting Started with the Eye Diagram Analyzer Getting Started with the Eye Diagram Analyzer In this chapter you will find information on the following topics Steps for Setting Up Eye Diagram Analysis 1 4 Step 1 Connect the Equipment 1 12 Step 2 Load the Personality 1 16 Step 3 Complete the Installation Using the Screen Instructions 1 19 Step 4 Set Up the Measurement Conditions 1 22 Optional Step Save Instrument State as Preset State 1 26 The Agilent 71501D E ye Diagram Analysis You can configure the 71501D system as a high speed eye diagram analyzer using Option 005 eye diagram analysis software This software allows the sys tem to operate similar to a high speed s
95. nctions of softkeys change according to the menus displayed on the screen Sweep control amp A EJEA MENU Sweep triggering Nain ented we E te Se eee Traces Vertical a a a ee scale a Scale Places Were ae Ie Se moveable Markers marker on traces Config ae Tri Cht Configuration page 25 iv lof 2 ay Leads to 6 remaining menus Page 1 of Top Level M enus Eye Diagram Analyzer Reference Agilent 70820A Menus The Left Side Softkeys Use the softkeys located on the left side of the display to access the twelve major menus These softkeys are shown in two pages Press page 1 of 2 to view the second page of softkeys When the 70820A module first turns on the Main menu is automatically selected Pulse generator control a Automated waveforms Pulsgen measurements f Measure View and control harmonic Table table Create Analyze histograms war masks and limit lines aa Instrument States calibration Bes 2AB ps div Tri Chi i page 25 m div Predefined 2af GV ref measurement states Return to page 1 menus Page 2 of Top Level M enus 3 15 To Control the Number of Bits Displayed To Measure in Optical Power Units Eye Diagram Analyzer Reference Controlling the Display Controlling the Display The Setup menu s BIT INTVL softkey allows you to select the number of bits that will be displayed on the screen The
96. next user correction point can be a linear slope this is the default log slope or flat line l cht che tia ee usr cor 5 CRR SEL EDT h to FREQ HAGN FREQ SLOPE FLAT de value H W dB s ope 1 966240 GHz 3 HL dB slope INSERT 2 458320 GHz 5 71 dB slope LINE 4 976640 GHz 21 58 dB slope BG BH8 GHz 21 58 dB ather prey menu To Enter the User Correction Menu To Select a Channel for User Corrections To Turn User Corrections On and Off Eye Diagram Analyzer Reference Agilent 70820A User Corrections DELETE Pulsgen ALL DELETE Measure L INE actian Table lipy DIY path to FREG MAGN PHASE next FREQ siape Analyze LOG LIN de value B BA dE 4B8 deg slope 18 8HHH GHz B BA dB 48 deg Calib States copy ta CH2 page prey cof p menu Default Data Enter user correction data by manually using front panel keys or storing the results of a sweep to user correction memory Display the User Correction menu by pressing MENU page 1 of 2 Cali b user corr Select a channel for user corrections by pressing MENU page 1 of 2 Cali b user corr CH1 CH2 CH1 to select channel 1 CH1 CH2 CH2 to select channel 2 User correction can be turned on and off using either the Menu softkeys or the User softkeys e Use the Menu softkeys to turn user corrections on and off by pressing MENU page 1 of 2 Calib user corr usr cor ON OFF Use the User softk
97. one time Five default mask limit line shapes are provided for your use e hexagon square e equilateral triangle e inverted equilateral triangle e flat line You can stretch shrink or move any mask It is also easy to add additional points or delete unneeded points from any shape Both limit lines and masks can establish either upper or lower limits for a response Custom masks are easy to create by editing the supplied default shapes The compatible modes are eye eyeline and pattern trace Pulsgen Measure Table Analyze Calib States eas 120 492 ps GB PaP psfdiv ares Tri Cht M4 1 page dB m div Le A prev 2 aof 256 mY ref Tr de menu Example of a User Created Mask 2 23 Note 10 Application Tutorials Tutorial 7 Default and Custom Mask or Limit Line Testing Create a Mask or Limit Line Set the analyzer to a known state by pressing INSTR PRESET Setup BIT INTVL and enter 1 5 Traces persist VARIABL PERSIST SWEEPS and enter 8 MENU page 1 of 2 Analyze masks limits define shapes type e If you want to create a mask press MASK e If you want to create a limit line press UPPER LIMIT or LOWER LIMIT Select a Default Mask Shape Select the shape that most closely matches the mask you need F or example to display a hexagon press default shapes hexagon Edit the Shape To edit the shape press edit Move a Point To move a point select the point to be move
98. or TRIGGER TRIGGER a This connection provides faster trace updates Entering the pattern generator s settings The Setup menu s READ PAT GEN softkey queries the 70841 pattern genera tor and 70311A signal generator for the clock frequency pattern length and any divide ratios In the case of alternate configurations an appropriate sub menu will be displayed for the parameters that require manual updating A READ PAT GEN should be performed after changing pattern generator settings such as clock frequency or pattern length Moving the measurement plane Specifying an attenuation on channel 1 changes the measurement plane from the front panel RF INPUT 1 connector to include the indicated attenuation Specifying any attenuation on channel 2 may be necessary to ensure proper triggering Use the Trg Cal menu s CH1 EXT ATTEN and CH2 EXT ATTEN softkeys to specify any external attenuation Getting Started Steps for Setting Up Eye Diagram Analysis These softkeys can also be used to specify an optical to electrical responsivity conversion between the source and input channels As a result the display shows optical units referenced to the input of the optical to electrical con verter Channel and marker readouts change to watts div Also the CH1 EXT ATTEN softkey changes to read CH1 RSPVTY responsivity Autoranging The Trg Cal menu s autorng ON OFF softkey turns on or off autoranging When autoranging is activated the eye dia
99. orrections on page 3 49 Eye Diagram Analyzer Reference Agilent 70820A Calibration RF 4 ge ere Pul RF carr factors mae ee ON OFF Adds Measure oo delay ener to a chan channel Table of J sken ec eia ee Automatic Analyzef lea ih We M calibration JseLF routines Calib TEST J sei Calibration N cal test meny i s 1E na div 21971 Tri ChL page 25 mediv Manual 2af 2 AY ref calibrator control The Calibration Menu Turning Off RF Correction The microwave transition analyzer module applies RF correction factors to all measurements These correction factors are loaded into nonvolatile memory at the factory You can prevent the use of RF correction factors during mea surements Note Eyeline and pattern modes are required RF corrections can only be applied in eyeline and pattern modes RF corrections must be off in eye mode To Turn Off RF Correction Turn off RF correction by pressing MENU page 1 of 2 Cali b RF corr ON OFF OFF Eye Diagram Analyzer Reference Agilent 70820A Calibration Matching Delay Between Channels Significant delays can occur between the signals on channel 1 and channel 2 when the electrical lengths of external cabling varies This results in a phase offset between the two channels The microwave transition analyzer module offers the capability to add delay to either channel 1 or channel 2 The following figure shows added de
100. owing figure shows 350 V Watt entered Notice the soft key label changes to CH1 RSPVTY responsivity Setup SINGLE CHL responsivity F J a58 YHat F psa CONT Trg Cal Traces Measure f PSUTY CHE EXT ATTEN Marker OFFSET Masks CAL B s 100 469 psfdiv Tri Chi ass 254 uh div mare Storage ABA ul ref 1 of 2 2 To use the markers to read optical power press Markers Y1 3 Adjust the marker line to the peak of the response F or example the following figure shows a peak optical power of 1 5 mW Application Tutorials Tutorial 2 Measure in Optical Power Units Setup Yi 1 5 mH lee Y1 adjust Trg Cal t miea ae Traces Measure Markers Masks Tri Cht ass 250 ull div Storage ABA ul ref B s 140 469 psfdiv 2 9 Application Tutorials Tutorial 3 Measure Extinction Ratios on Low Level Signals Tutorial 3 Measure Extinction Ratios on Low Level Signals Repeatable extinction ratio measurements can be made on low level signals This is accomplished by applying a filter to the signal This filter improves measurement sensitivity and is useful for analyzing e low level extinction ratios pattern dependent transitions e intersymbol interference In this tutorial the eye diagram analyzer is placed in eyeline mode so that the eye filter can be ap
101. plied to reduce trace noise To measure the signal a photo diode converter with a responsivity of 30 volts watt is used When making extinction ratio measurements in eyeline mode the number of samples should be increased from the default of 1000 to something on the order of 20000 This insures a number of traces are evaluated to compute the extinction ratio The compatible mode is eyeline Change to E yeline Mode Set the instrument to a known state by pressing INSTR PRESET Setup diagram EYELINE Traces Set the number of persistence sweeps by pressing persist VARIABL PERSIST SWEEPS and enter 5 prev menu Turn on autoscaling by pressing Trg Cal more 1 of 2 Traces AUTO SCALE The display should look like the following figure A low amplitude response similar to that shown in this figure can result when using non amplified lightwave converters to measure optical signals Application Tutorials Tutorial 3 Measure Extinction Ratios on Low Level Signals Setup INF INIT Trg Cal Traces Measure Markers Widad Masks OFF Bos 100 465 psfdiv Trt Cht Mass 8 mW div prey Storage ie my ref menu Autoscaled Display of Low Level Signal Turn filtering on by pressing Setup eyefltr ON OFF ON Perform an Offset Calibration This calibration procedure removes any offset that may be present in the opti cal to electrical converter This is someti
102. point violations are to be counted as errors press count TRC DOT DOT To select when testing should stop press end on If you want testing to stop after a set number of errors press errors ON OFF ON desired number of errors If you want testing to stop after a set number of traces press traces ON OFF ON desired number of traces To begin testing press test ON OFF ON 23 24 25 26 27 28 Application Tutorials Tutorial 7 Default and Custom Mask or Limit Line Testing Display the Error Trace Display a mask and begin testing as described in this section and then press err trc ON OFF ON Erasea Mask or Limit Line Select the mask or limit line you wish to erase by pressing MENU page 1 of 2 Analyze masks limits define shapes edit SELECT the number of the mask or limit line to be erased Erase the mask by pressing delete shapes DELETE CURRENT Remove all Displayed Masks Remove all displayed masks by pressing Masks mask setup To temporarily prevent the display of a mask without removing it press display ON OFF OFF To remove the mask press CLEAR MASKS Refer to Applying Mask Testing on page 3 31 to learn more about saving recalling and erasing masks Application Tutorials Tutorial 8 Display the Data Pattern Tutorial 8 Display the Data Pattern The eye diagram analyzer can display the data pattern This is done by select ing the pattern mode and triggering the display trace
103. quare wave Frequency 153 Hz to 5 MHz Amplitude 5 positions The signal s amplitude can be set to one of five positions 0 through 4 Zero represents the smallest available amplitude Four represents the largest amplitude These settings do not correlate to any specific amplitude and may vary between instruments To Turn the Calibrator Signal On To Change the Calibrator Frequency and Amplitude Eye Diagram Analyzer Reference Agilent 70820A Calibration ta cal sig Pulsgen ON OFF cal signal freq Measure MHz Table ANP L Analyze Calib States 1 1 1 Hos 1H nsfdiv Trt Cht page g5 mfdiv prev cof P AN ref menu To turn the calibrator signal on press MENU page 1 of 2 Calib cal signal cal sig ON OFF ON To change the calibrator frequency and amplitude press MENU Calib cal signal FREQ 156 Hz 5 MHz AMPL 0 4 Programming Commands Note Programming Commands Programming Commands Programming Commands This chapter documents programming the eye diagram analyzer You will find the preview feature discussed in this chapter very useful It displays the programming command corresponding to the response received when most softkeys are pressed You will find information on the following commands in this chapter ALIGN 4 4 BIT 4 5 CLEAR 4 5 DEFAULT 4 6 DELAY 4 7 DIAGRAM 4 7 EXTIN 4 8 MARGIN 4 9 MARMSK 4 9 MEAS 4 10 PERSIST 4 11 QUIT 4 12 Prog
104. r of automatic histogram measure ments on an eye diagram Use the r f tim ON OFF softkey to enable rise time and fall time measurements during the measure eye routine This approximately doubles the measurement time e Usethe UPPER THRSHLD and LOWER THRSHLD softkeys to set the upper and lower edges for rise time and fall time measurements These softkeys define the amplitude level to be used for the upper and lower parts of an edge definition for the automatic measurement functions e The default upper threshold is 80 The default lower threshold is 20 Measurement Definitions This measurement is the ratio of the most prevalent high level to the most prevalent low level over one bit interval The measurement results are dis played in both linear and logarithmic 10log forms of the ratio The peaks of the histogram are used to Set initial limits for the computation of the one and zero levels The initial mean and sigma of the one level is based on histogram data above the relative 50 point of the peaks The limits for the next evaluation of the histogram data are set to the initial mean plus or minus one sigma The new mean and sigma for the one level is determined This pro cess iterates several times until the sigma becomes small and the mean con verges on the most prevalent one level The determination of the most prevalent zero level is based on the same algorithm except the initial mean and sigma of the zero level are based on
105. rage Working with Files Files are identified by a prefix and a name The eye diagram analyzer assigns a prefix according to the type of data as shown in the following table You enter the file name When cataloged the file listings show the file s data type and size in bytes File Prefixes File Type File Prefix Calibration data C Histograms h_ Instrument registers r Instrument state S_ M ask Limit line m_ Program d Trace t User corrections a_ User menu k J itter template T You can create additional prefix text for your file names The text appended to the standard prefixes allows you to indicate files that have similar data For example the following figure shows a catalog of two mask files Each file has an additional prefix of Shape The additional prefix is appended regardless of the type of file you are saving The total length of your file name cannot exceed 10 characters for LIF and 8 characters for DOS This includes prefix and file name To Duplicate a Memory Card Eye Diagram Analyzer Reference Saving to Mass Storage msi pulser WP MSIB Measure aPBER E PAGE E 4NEXT Table F TPAGE Fret ix 1 Analyze SI HP MSIB 4 Page 1 ae m_Shape_1 ASCII 216A m_Shape_c ASCII 2560 Cal ib tend of catalog save States more page prev cafe menu Instrument BASIC provides the ability to mass copy all the files from one memory card to another memory card This allows you to eas
106. ramming Commands Introduction Introduction Before communicating with the eye diagram analyzer application the Instru ment BASIC system must be queried for the name of the program and told we wish to communicate with this program The following example shows how to do this OUTPUT M ta PROG CAT Request list of currently loaded programs ENTER M ta Name There can only be one at present OUTPUT M ta PROG NAM E Name Send program name Use Variables to Pass Commands and Data Because the 70874A is an Instrument BASIC program normal programming techniques are not employed Instead program control is achieved through manipulating three 70874C program variables Command Param and Response Strings and numbers are passed to these variables via two micro wave transition analyzer commands PROG STRing PROG NUMBer The Command string variable directs the 70874C to perform an action Twelve possible command strings are documented in this chapter ALIGN BIT CLEAR DEFAULT DELAY DIAGRAM EXTIN MARGIN MARMSK MEAS PERSIST QUIT Load the Param variable with a parameter for the selected Command variable string Because execution begins immediately after Command is loaded load Param before Command Param is actually two variables with the same name one is a string variable the other is a numeric variable After execution of a command the Response string variable contains any resulting query d
107. rams If the amplitude of the trigger signal is too large an over range message is displayed If a message is displayed reduce the amplitude of the signal use an external attenuator and enter the value using CH2 EXT ATTEN If an 70841A B pattern generator is used press READ PAT GEN The eye diagram analyzer reads the settings of the pattern generator 8 If apattern generator such as the 70843A 71612A is used in place of an Generator Settings 6 7 9 10 Note 11 70841A B pattern generator press READ PAT GEN CLOCK RATE and enter the rate of the clock signal CLOCK DIVISOR and enter the divisor for the clock signal For example when using a trigger or sync output enter 16 if the clock signal is divided by 16 Enter the pattern repetition length by pressing PATTERN LENGTH and enter the pattern repetition length The pattern repetition length is entered in bits or as the binary power depend ing on the position of the 2 n 1 ON OFF softkey If the function is on binary powers are entered in the form 2 1 This makes it very easy to set the pattern length for PRBS sequences When the function is off the pattern length is entered directly in bits Press PAT TRG FACTOR and enter the factor that relates how many repetitions of the pattern occur between trigger pulses Frequently 16 to 32 or more repetitions of the pattern occur between trigger pulses When operating off a trigger or sync output with a divided cloc
108. rkers TRC 007 Masks es paras 120 852 ps Gi ede pa div l Trt Cht Mi Nass 5p md LE Storage 16a m ref L3 A Tr 166 Limit line 3 L3 Error counts Eye Diagram Analyzer Reference Applying Mask Testing Automatic Alignment Scales the Mask The MASK ALIGN softkey located under the Masks menu automatically aligns and scales a default mask to the data per the SONET SDH standards This is accomplished using histograms and is best done in eye mode for faster and more evenly distributed data acquisition Eye mode provides a more even statistical distribution of high and low data This results in faster acquisition of the histogram data used to determine zero and one levels The mask and limit lines adjust to fit the displayed data To change the number of samples used for the histogram use the Measure menu s NUMBER SAMPLES function Display the Error Trace Use the err trc ON OFF softkey to display a trace that violates a mask The screen is split with the error trace displayed in the lower half of the display Trace four is allocated as the error trace Number of error traces diagram Setup EYELINE Trg Cal Traces Measure INTUL Error traces Markers eyef ltr 1 20563 ne J21 Sde pardiy 10E Tri Chi Tr4 Errors Mi ass BA mV div 188 mVfdiv LE 2 CLEAR Storage iBA mY ref 168 mY ref L3 Tr 13 DISPLAY Masks Number of traces counted Mask Margins Tigh
109. rming Eye Diagram M easurements Performing Eye Diagram Measurements To perform the automatic eye diagram measurements use the Measure menu With the exception of extinction ratio these measurements must be per formed in eye mode Automatic Measurements The Measure menu s top two softkeys automatically start measurements e EXTINCT RATIO e MEASURE EYE Measure menu lt Extin 1 Lew B Lev Eye H Crossing Level Eye Width Eye Jitter to Mean Rise Time Mean Fall Time 5 B44 239 27 EN 164 92 127 3B 291 84 55 016 44414 74 BEG dB ny ny amp z Bit Bit Bit Bit Extinction ratio Typical eye E measurements im Rise and fall time e Usethe EXTINCT RATIO softkey to automatically compute the extinction ratio in eye or eyeline modes This measurement is a ratio of the most prevalent log ical one level divided by the logical zero level over one bit interval When mak ing extinction ratio measurements in eyeline mode the number of samples should be increased from the default of 1000 to approximately 20000 This in sures that anumber of traces are evaluated to compute the extinction ratio Extinction Ratio 1 Level mean o 0 Level mean o Eye Height Eye Diagram Analyzer Reference Performing Eye Diagram M easurements Use the NUMBER SAMPLES softkey for this purpose Use the MEASURE EYE to initiate a numbe
110. s instrument state files The prefix M_ identifies mask limit line files Load the file by pressing LOAD FILE To Save a Mask Limit Line File To Recall a Mask Limit Line File To Erase a Mask File Limit Line File Eye Diagram Analyzer Reference Saving to Mass Storage Display the Mass Storage menu by pressing States more 1 of 2 mass storage If the mass storage device needs to be selected refer to Selecting and F or matting Memory on page 3 34 Enter the file name by pressing save save misc SAV MSK LIM Use the softkeys knob numeric keypad and step keys to enter the file name Save the file by pressing ENTER LINE To recall a mask limit line file press MENU page 1 of 2 States more 1 of 2 mass storage If the mass storage device needs to be selected refer to Selecting and Formatting Memory on page 3 34 Rotate the front panel knob to select highlight the desired file Load the file by pressing LOAD FILE To erase a mask limit line file press MENU page 1 of 2 States more 1 of 2 mass storage If the mass storage device needs to be selected refer to Selecting and Formatting Memory on page 3 34 Rotate the front panel knob to select highlight the desired file Erase the file by pressing more PURGE FILE Note To Create a Print Ww Eye Diagram Analyzer Reference Creating Copies of the Display Creating Copies of the Display Often it is importan
111. se the front panel knob or numeric keypad to position each displayed marker on the screen Notice that the value at the marker is displayed on the top portion of the screen To turn the markers off simply press MARKERS OFF Ma Setup Trg Cal Traces Markers 7 menu oS easure Markers Masks Mass Starage rker positions 1 74 3474 ps x2 44 28 Marker separation x 65 ps X 2 t 96 1484 ps Ac adjust A 44 206546 ps Wy BFAR y ji Bos 4B 18B ps div Trt Cht iBA m div 32d mY ref ap TRL Ke D TRL fI area ioff MEESE off MARKERS OFF Eye Diagram Analyzer Reference Applying Mask Testing Applying Mask Testing Use the Masks menu to display and control mask testing Built in standard masks for the more common SONET SDH transmission rates are provided To learn how to create your own custom masks refer to Chapter 2 Application Tutorials Test Results are Displayed During mask testing mask violations are displayed in the lower portion of the display You can specify whether the mask errors are counted as trace errors or as the number of trace points or dots that violated the mask You do this using the count TRC DOT softkey Limit line 2 L2 Mask 1 M1 Setup setup Trg Cal ONI OFF I errors races N OFF iedere traces N OFF count Ma
112. ss storage more CHANGE PREFIX Enter the desired text To enter the prefix press ENTER LINE Entering the prefix without a keyboard a Turn the front panel knob to move the character select cursor b Press SELECT CHAR to enter a character at the character select cursor c Press the numeric keypad to enter numbers or a minus sign d TheINSERT or softkey determines the action of the SELECT CHAR soft key Choices are INSERT acharacter REPLACE an existing character or DELETE acharacter e Press the ft and U keys beneath the front panel knob to move the com mand entry cursor f Use the CLEAR TO END softkey to remove characters from the command entry cursor to the end of the command ToEraseaCustom Prefix To Save an Instrument State 1 2 3 To Load a State or Mask Limit Line Eye Diagram Analyzer Reference Saving to Mass Storage To erase a custom prefix press MENU page 1 of 2 States more 1 of 2 mass storage more CHANGE PREFIX Repeatedly press the U step key until the cursor is located at the start of the custom text Clear the text by pressing CLEAR TO END ENTER LINE Set the eye diagram analyzer to the desired settings Insert a ROM card into the front panel card slot Save the instrument state by pressing Mass Storage SAVE STATE Insert a ROM card into the front panel card slot and then press Mass Storage Rotate the front panel knob to highlight the desired file The prefix S_ identifie
113. st one of the following is true e The temperature has changed 5 Centigrade since the last calibration was performed More than one week has passed since the last calibration Before any critical measurement Note To Calibrate the IF To View the Last Calibration Date Eye Diagram Analyzer Reference Agilent 70820A Calibration Warm up time Allow the microwave transition analyzer module to warm up for at least one hour before performing a calibration Connect a low loss cable between the front panel CALIBRATOR OUTPUT and channel 1 connectors To calibrate the IF press MENU page 1 of 2 Calib IF calib CAL CH1 CAL CH1 The calibration routine takes about 30 minutes to complete Disconnect the cable from channel 1 and connect it to the channel 2 connector Repeat the above procedure for channel 2 Turn any displayed traces off to make viewing the calibration date easier Continue by pressing MENU page 1 of 2 Cali b IF calib cal debug show To view when channel 1 was last calibrated press CH1 CAL INFO To view when channel 2 was last calibrated press CH2 CAL INFO To View IF Correction Data Traces Eye Diagram Analyzer Reference Agilent 70820A Calibration Viewing the Calibration Data The ability to view the IF calibration data is mainly intended for service pur poses However the procedures in this section show you how to view the data Display the Traces menu by pressing
114. stered trademark of the European Commu nity The CSA mark is a reg istered trademark of the Canadian Stan dards Association The C Tick mark is a registered trademark of the Australian Spec trum Management Agency This text denotes the instrument is an Industrial Scientific and Medical Group 1 Class A product ISM1 A Typographical C onven tions The following conventions are used in this book Key type for keys or text located on the keyboard or instrument Softkey type for key names that are displayed on the instru ment s screen Display type for words or characters displayed on the computer s screen or instru ment s display User type for words or charac ters that you type or enter Emphasis type for words or characters that emphasize some point or that are used as place holders for text that you type WARNING WARNING WARNING WARNING WARNING General Safety Considerations General Safety Considerations This product has been designed and tested in accordance with the standards listed on the Manufacturer s Declaration of Conformity and has been supplied in a safe condition The documentation contains information and warnings that must be followed by the user to ensure safe operation and to maintain the product in a safe condition Install the instrument according to the enclosure protection provided This instrument does not protect agains
115. straight into the removal hole and the keypad will pop out Channel 1 Channel 2 Clock Out pobSa 6 dB ATTENUATOR 1 3 kr WN rPe Connect the Equipment Load the E ye Diagram Personality Complete the Installation Using Self Guided Screens Getting Started Steps for Setting Up Eye Diagram Analysis Steps for Setting Up Eye Diagram Analysis Connect the equipment Load the eye diagram personality Complete the installation using the self guided screens Set up the measurement conditions You can connect the equipment in three possible configurations e With 70841A B pattern generator and 70311 clock source modules This is the preferred configuration e With an 70841 pattern generator module with a non 70311 clock source module e With non MMS70841 pattern generator and clock source modules Each time the 71501D is turned on the 70874A eye diagram analyzer person ality part number 70874 10001 must be loaded into memory This occurs automatically if the 70874A memory card is inserted in the front panel card slot before the instrument is turned on You can also load the personality in a manual mode Installing the eye diagram analyzer is easy due to a series of self guided screens Depending on the factory configuration of your system one or more of these screens may not be displayed After connecting the equipment and loading the program you ll need to respond to a s
116. t the ingress of water This instrument protects against finger access to hazardous parts within the enclosure If this product is not used as specified the protection provided by the equipment could be impaired This product must be used in a normal condition in which all means for protection are intact only No operator serviceable parts inside Refer servicing to qualified service personnel To prevent electrical shock do not remove covers This is a Safety Class 1 Product provided with a protective earthing ground incorporated in the power cord The mains plug shall only be inserted in a socket outlet provided with a protective earth contact Any interruption of the protective conductor inside or outside of the instrument is likely to make the instrument dangerous Intentional interruption is prohibited To prevent electrical shock disconnect the instrument from mains before cleaning Use a dry cloth or one slightly dampened with water to clean the external case parts Do not attempt to clean internally For continued protection against fire hazard replace line fuse only with same type and ratings type nA nV The use of other fuses or materials is prohibited CAUTION CAUTION CAUTION CAUTION CAUTION General Safety Considerations Fiber optic connectors are easily damaged when connected to dirty or damaged cables and accessories The Agilent 71501D s front panel input connector is
117. t to create hard copies of the display for reports or records A copy of the display can be printed on any Hewlett Packard graphics printer These printers support the Hewlett Packard PCL printer language and include the following e Think et e Paint et e Laser et The printer must have an GPIB interface Hard copies can be produced on a Hewlett Packard plotter if the eye diagram analyzer is in pattern mode Plots cannot be produced in eye or eyeline modes Connect the printer to the display via an GPIB cable Be sure to connect the GPIB to the display s connector not to the connector on the 70820A microwave transition analyzer module The first time the printer is used enter the printer type and address by pressing DISPLAY Hard Copy printer address GPIB TLK LSN to configure the printer in talk listen mode on the GPIB GPIB L ONLY to configure the printer in listen only mode on the GPIB To configure the printer via the HP MSIB use the HP MSIB COLUMN and HP MSIB ROW softkeys to enter the printer address To select the type of printer used press lt printer config Use the softkeys along the right side of the display to select the printer type To Create a Plot Eye Diagram Analyzer Reference Creating Copies of the Display Select the print option by pressing lt copy options COPY IS PRT PLT PRT Create the print by pressing USER PRINT Hard copies can be produced on an Hewlett Packard plotter if the e
118. ten Mask Tests Margins can be added to the mask limit line tests This margin is added as a percent of the mask Zero percent margin corresponds to the default mask One hundred percent margin corresponds to the mean of the histograms of the one and zero levels and the crossing points Negative mask margins can also be implemented These can be used to gain an idea of time severity of the encountered errors Eye Diagram Analyzer Reference Applying M ask Testing Added mask margin Mask Margin mask stp an Mask Margin rae ie Traces Hee Enter mask Heastire E margin MARGIN Turn margin k mar Hark mg mask on Masks ee QN OFF menu nas a 124 092 ps BB PAP ps div Tri hi M4 M4 A Hass 5P m div Le 2 Lo 4 prev Storage 164 mV ref Lo LB Tr JE menu Mask error counts The Mask Setup Submenu N Margin mask error counts 3 33 Eye Diagram Analyzer Reference Saving to Mass Storage Saving to Mass Storage Use the Mass Storage menu to save and recall files to a mass storage device The mass storage device is normally a memory card that has been inserted into the front panel card slot You can also store data to a GPIB disk drive and to internal random access memory RAM disk refer to Selecting and F or matting Memory on page 3 34 Each file that you save has a name that consists of a prefix followed by a cus tom name that you enter The an
119. the command To Recall a User Correction File To Erase a User Correction File Eye Diagram Analyzer Reference Agilent 70820A User Corrections To recall a user correction file press MENU page 1 of 2 States more 1 of 2 mass storage If the mass storage device needs to be selected refer to Selecting and Formatting Memory on page 3 34 Rotate the front panel knob to select highlight the desired file Load the file by pressing LOAD FILE To erase a mask limit line file press MENU page 1 of 2 States more 1 of 2 mass storage If the mass storage device needs to be selected refer to Selecting and Formatting Memory on page 3 34 Rotate the front panel knob to select highlight the desired file Erase the file by pressing more PURGE FILE Eye Diagram Analyzer Reference Agilent 70820A Calibration Agilent 70820A Calibration Use the Calibration menu to perform the following tasks e Match delay between channels e Initiate an instrument self test routine e Turn off RF correction e Calibrate the IF e Verify the calibrator signal The Calibration Menu The automatic IF calibrations documented in this section ensure accurate measurements using the eye diagram analyzer RF correction data resides in nonvolatile instrument memory and does not need to be changed unless repairs have been made The Calibration Menu s user corr softkey features are documented in Agilent 70820A User C
120. ting Up Eye Diagram Analysis Eyeline Mode Eyeline mode displays continuous traces Use this mode for the following e Measure extinction ratio e Measure laser turn on transition delay e Examine laser overshoot e Observe laser ringing e Apply eye filter Apply user corrections Bs 100 465 psfdiv Tri Cht gH mvfdiv 244 mW ref 1 7 Pattern Mode Getting Started Steps for Setting Up Eye Diagram Analysis Pattern mode displays the actual PRBS data stream bits This mode uses the pattern trigger which allows the display to show the same portion of the data stream from sweep to sweep M paad ad ys aiaa ns ABI 7B ps div Tri Cht aB mfdiv 240 mY ref Mask limit lines provide pass fail testing Mask limit lines are displayed geometric shapes that define the acceptable limits and shape of an eye diagram The following figure shows a mask Use masks for pass fail testing and as an aid to error analysis The eye diagram analyzer can capture and display the portion of the pattern that caused a mask violation Built in standard masks for the major SONET SDH transmission rates are provided and can be applied with the press of a softkey Or you can create your own custom masks Getting Started Steps for Setting Up Eye Diagram Analysis Mask Limit line mask Setup setup test Tra Cal L ON OFF Traces errars ONJ OFF teanira tr
121. tkey presents a menu used for controlling trace averaging Trace averaging keeps a running average of the measurement val ues on each sweep You can set the averaging count its default value is 16 Trace averaging is only applied to trace 1 Eye Diagram Analyzer Reference Displaying Traces Press to turn averaging on Setup average ON OFF Press to enter Tra C taveragE averaging count ae SHEEPS Traces Measure Narkers k Masks 1 f 1 f f Hs 100 469 psfdiv Tri Cht ass 2p m div prev Starage YB mY ref Tr menu The Averaging Submenu Average trace 1 by pressing Traces average AVERAGE SWEEPS and enter the number of sweeps used for running average average ON OF F ON Four Persistence Modes are Available The eye diagram analyzer offers four trace persistence selections These selections are located under the Traces menu s persist softkey and include the following types e Infinite monochrome e Variable monochrome e Color grading e Monochrome grading Trace persistence works on all displayed traces regardless of which trace is selected 3 27 Eye Diagram Analyzer Reference Displaying Traces Infinite monochrome Variable monochrome Set up INFINIT ea TT IT Trg Cal go AR TABL ee A grading Traces COLOR DING Monochrome 4 radin iT NO o g FA Puree RAGING S Set number of Harkes PERSIST persistence me MEEPS EW EEDS Hasks i 5 1 A OFF Es 106 465 ps d
122. transfer function 2 30 M manually load the personality 1 17 manually set the trigger level 1 25 MARGIN command 4 9 markers using 3 30 Index 3 Index markers turned on 2 13 markers menus 3 13 MARMSK command 4 9 mask align 3 32 mask and limit lines 1 8 mask margins 3 32 mask or limit line creation 2 24 mask or limit line editing 2 24 mask setup menu 3 33 mask testing applying 3 31 modes available 1 5 masks and limit lines 3 9 masks and limit lines description 3 9 masks displayed on screen 3 9 masks menus 3 13 mass storage 3 34 mass storage menus 3 13 matching delay between channels 3 63 mean fall time description 3 5 mean rise time description 3 5 MEAS command 4 10 measure in optical power units 3 16 measure menus 3 13 Measurement Conditions 1 22 measurement plane 1 10 1 26 measurements definitions 3 4 extinction ratio 2 6 2 12 fast amplitude and phase transitions 3 5 in optical power units 3 16 laser turn on delay 2 13 optical power units 2 8 memory selecting and formatting 3 34 memory card battery 3 39 duplicate 3 41 loading personality 1 18 memory card formatting 3 37 memory cards 3 34 menus 70820A 3 14 Agilent 70820A 3 14 averaging 3 27 calibration 3 62 eye diagram 3 12 histogram 3 7 left side 3 15 maps 3 12 mask setup 3 33 module main 1 17 persistence 3 28 setup and trg and cal 3 12 setup and trg cal 3 12 trac
123. ttern mode 2 29 V values of program variables 4 5 variable monochrome persistence 3 28 variables to pass commands and data 4 3 vertical histogram 2 36 viewing 70820A menus 3 20 calibration data 3 66 3 68 date and time 3 21 error trace 3 32 hardware response traces 3 67 IF correction data traces 3 66 last calibration date 3 65 repetitive and non repetitive signals 3 5 signal in optical units 2 12 the firmware date code 3 20 user correction data 3 56 Index 6
124. tting a memory card 3 37 formatting memory 3 34 four traces can be displayed 3 25 front panel connections 1 14 Sh G generating histograms 3 7 getting started with the eye diagram analyzer 1 2 GPIB disk 3 37 GPIB disk drives 3 36 guided instructions 1 20 H histogram menu 3 7 histogram type selection 2 36 histogram horizontal creation 2 41 histogram selection 2 36 Index histogram vertical creation 2 36 histograms generating 3 7 horizontal histogram creation 2 41 l IF calibration 3 64 improve the sensitivity in eyeline mode 3 17 industry standards testing 2 19 infinite monochrome persistence 3 28 initializing a memory card 3 37 input connector 1 iv INSTR PRESET key definition 1 11 instructions on the screen 1 19 internal RAM disk 3 37 interpolation flatline 3 55 interpolation logarithmic slope 3 55 K keypad custom 1 3 L aser and optical to electrical converter 1 15 aser bias affects overshoot 2 5 aser overshoot and turn on delay 2 14 aser overshoot filtered 2 18 eft side menu keys 3 15 imit line displayed on screen 3 10 imit line or mask creation 2 24 imit line or mask editing 2 24 imit line or mask testing 2 23 imit lines and mask 1 8 oad state or mask or limit line 3 45 oad the personality 1 16 oading software filter 2 17 ogarithmic slope interpolation 3 55 ow level signals extinction ratios 2 10 ow pass filter from a
125. ve not already connect the cables to 1 21 Select the Mode Select Single or Continuous Sweeps Select Trigger Source Getting Started Steps for Setting Up Eye Diagram Analysis the instruments front panels follow the instructions shown Otherwise proceed with If you have not already connect the cables to the instruments front panels follow the instructions shown Otherwise proceed with If you have not already connect the cables to the instruments front panels follow the instructions shown Otherwise proceed with on page 1 21 on page 1 21 on page 1 22 on page 1 22 Step 4 Set Up the Measurement Conditions To select the mode press Setup diagram EYE EYELINE or PATTERN Press the left side Trg Cal softkey Select one of the following sweep states Press SINGLE to select single sweeps Each additional press of this softkey triggers another sweep Press CONT STOP_CONT to select continuous sweeps Press CONT STOP STOP to stop the sweeps Press the left side Setup softkey 5 Press CH2 e Ifthe pattern generator s CLOCK OUT signal is connected to the RF INPUT 2 connector press CLK OUT e Ifthe pattern generator s TRIGGER OUT signal is connected to the RF IN PUT 2 connector press TRG OUT Note Select the Pattern Getting Started Steps for Setting Up Eye Diagram Analysis Using the CLOCK OUT trigger signal provides faster data acquisition for eye diag
126. ye dia gram analyzer is in pattern mode Plots cannot be produced in eye or eyeline modes Connect the plotter to the display via an GPIB cable Be sure to connect the GPIB to the display s connector not to the connector on the 70820A microwave transition analyzer module The first time the plotter is used enter the plotter type and address by pressing DISPLAY Hard Copy plotter address HP IB TLK LSN to configure the plotter in talk listen mode on the GPIB HP IB L ONLY to configure the plotter in listen only mode on the GPIB To configure the plotter via the HP MSIB use the HP MSIB COLUMN and HP MSIB ROW softkeys to enter the plotter address 3 To select the type of plotter used press lt plotter config Use the softkeys along the right side of the display to select the plotter type 4 Select the plotter option by pressing lt copy options COPY IS PRT PLT PLT 5 Create the plot by pressing USER PLOT Eye Diagram Analyzer Reference Agilent 70820A User Corrections Agilent 70820A User Corrections User corrections provide a convenient method for modifying the display of input signals Some of the applications for user corrections include the follow ing e Filtering input signals to simulate the effects of circuit design Compensating for frequency and phase response of external probes Compensating for frequency and phase response of external test setups e Compensating for the frequency r

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