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HP 86120A Multi-Wavelength Meter

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1. Item ie Oty Description 1 08703 20098 1 Universal fiber optic connector 2 0535 0031 12 Nut hex with lock washer M3 x 0 5 2 4 mm thick 3 0515 0664 1 Screw TORX T10 Pan Head M3 x 0 5 12 mm long 4 0515 0374 7 Screw TORX T10 Pan Head M3 x 0 5 10 mm long 5 86120 20007 1 Front frame 6 0515 0373 1 Screw TORX T10 Pan Head M3 x 0 5 10 mm long 7 0515 0372 4 Screw TORX T10 Pan Head M3 x 0 5 8 mm long 9 5041 1682 1 LINE key Part of W12 10 0515 0430 8 Screw with washer TORX T10 Pan Head M3 x 0 5 6 mm long 11 5041 8928 4 Front frame bumper 12 4040 2331 1 Filter mesh window 13 86120 00005 1 Front panel faceplate 5 50 Servicing Replaceable Parts 6 places Display Window 1 place rpfrtpr 5 51 Servicing Replaceable Parts Table 5 10 Rear Panel Parts Item mT Qty Description 1 1 HP IB connector Part of W7 2 1 Parallel port connector Part of W7 3 2190 0034 2 Washer lock HLCL No 8 0 168 in ID 4 0380 0644 2 Standoff hex 0 255 in long 6 32 thread 5 2190 0584 2 Washer lock HLCL 3 0mm 3 1 mm ID 6 2 mm OD 6 1251 7812 2 Jackscrew 7 0360 0269 1 Terminal solder lug 8 0535 0082 5 Nut hex with lock washer M4 x 0 7 3 2 mm thick 9 0535 0082 4 Nut hex with lock washer M4 x 0 7 3 2 mm thick 0 0515 0382 2 Screw with washer TORX T15 Pan Head M4
2. pia A1A3 A1A1 A1A2 servopt Do not disturb any of the screws on the A1A1 A1A2 or A1A3 assemblies Loosening or tightening these screws destroys the amplitude and wavelength calibration so that the HP 86120A no longer meets its published specifications If the position of these screws is changed return the instrument to Hewlett Packard for service 5 5 Servicing General Information Table 5 1 Required Tools Tool HP Part Number Small Pozidriv screwdriver 8710 0899 Wire cutter 8710 0012 Long nose pliers 8710 1107 5 5 mm nut driver 8710 1220 7 mm nut driver 8710 1217 TORX T 10 driver 8710 1623 TORX T 10 key right angle Options AXE amp 1X4 8710 1657 TORX T 15 driver 8710 1622 4 mm hex key 8710 1755 5 6 Table 5 2 Internal Labels Servicing General Information VISIBLE LASER RADIATION WHEN OPEN DO NOT STARE DIRECTLY INTO BEAM OR VIEW WITH OPTICAL INSTRUMENTS 1 mW 633 nm CLASS IIIA LASER PRODUCT This label warns you that removing the A1A1 Interferometer Assembly s cover exposes the beam of a CLASS IIIA LASER PRODUCT Never remove this cover WARNING HIGH VOLTAGE This label warns you that high voltage circuits are located beneath the A1A3 Laser Assembly s cover Never remove this cover ATTENTION WARNING To prevent shock after unplugg
3. lt real gt is a frequency value that is within the following limits Constant Description MINimum 181 6924 THz MAXimum 428 6 THz Preset State 428 6 THz 700 nm RST State 428 6 THz 700 nm SCPI Compliance instrument specific The reference will be the laser line at the frequency closest to the frequency entered Subsequent measurements will use the frequency closest to the ref erence frequency used for the previous measurement The query returns the reference laser line s frequency The default units for the lt veal gt parameter is in Hz DELTa REFerence POWer Queries the reference laser line s power level CALCulate3 DELTa REFerence POWer Preset State not affected RST State not affected SCPI Compliance instrument specific Query Only Syntax Attribute Summary Description Syntax Programming Commands CALCulate3 Subsystem DELTa REFerence WAVelength Selects the reference laser line for DELTa calculations CALCulate3 DELTa REFerence WAVelength lt real gt MINimum MAXimum lt real gt is a wavelength value that is within the following limits Constant Description MINimum 700 0 nm MAXimum 1650 0 nm Preset State 700 nm 428 6 THz RST State 700 nm 428 6 THz laser line SCPI Compliance instrument specific The reference will be the laser line at the wavelength closest to the wave length entered Subsequent measurements will us
4. Err_msg 255 T C EGER Cme AR Mwm RE W H EAT UNTIL AND POS Suben Set OU EN OU EN IF command IF NO NOT BIT Cme 2 PU ER PU ER Mwm Mwm Cme Mwm d SUBI 152 ND SUB CoM Ins OUTPUT END SUBI Ident s Set_es trument Mwm wm ESE ESR SYST Err_msg D NOT POS Cmd_msg makes t POS Err_msg 0 AND NOT BIT Cme 4 Err_msg 0 ERR Err_mngmt OPTIONAL Cmd_msg Instrument Mwmt Err_msg 0 he following error This THEN PRINT THI ity DEF FNIdentity COM Ins DIM Iden Identity trument Mwm tity 50 OU PUT Mwm RST U PUT Mwm OPC ER Mwm Opc_done O OU PU wm IDN ER Mwm Identity RE FNEND Cmd_o URN Identity pc SU COM Instrument Mwm OU PUT Mwm Set_cmd OU PUT Mwm OPC EN ER SUBI Tempo END wm Opc_done SUB Tempo Temp FOR I Temp TO 0 STI Waiting for VALS I SUBI NEXT I D DISP WAIT 1 END B Cmd_opc Set_cmd BP STA EN PRINT IVAL 00110100 2 sec Err_msg AND NOT BIT Cme 5 3 38 Programming Example Programs Example 4 Measure laser line separation This
5. RE FNEND 3 35 Programming Example Programs Example 3 Measure a Fabry Perot laser s drift This program measures the drift of a Fabry Perot laser It measures drift in both power and wavelength of each line First the program sets the HP 86120A in the continuous acquisition measurement mode Then it mea sures drift using commands from the CALCulate3 subsystem Notice the use of the Tempo subroutine to pause the program for 10 seconds while the HP 86120A measures the drift on the laser The use of the Err_mngmt subroutine is optional Refer to the introduction to this section for a description of each subroutine that is contained in this pro gram COM Instrument Mwm ASSIGN Mwm TO 720 DIM Key 1 ON ERROR GOTO Error_msg Set_ese PRINT USING 37A 33A Multi Wavelength Meter Identity is FNIdentity ON TIMEOUT 7 5 CALL Err_mngmt Cmd_opc RST Cmd opc INIT CONT ON Cmd_opc CONF ARR POW WAV Turn on the drift calculation Cmd opc CALC3 DRIF STAT ON Err_mngmt CALC3 DRIF STAT ON Turn off all drift states Cmd_opc CALC3 DRIF PRES Err_mngmt CALC3 DRIF PRES Turn on drift reference stat Cmd_ope CALC3 DRIF REF STAT ON Err_mngmt CALC3 DRIF REF STAT ON Query the number of data points OUTPUT Mwm CALC3 POIN ENTER Mwm USING K Nb_pt ALLOCATE Current_ref_wl 1 Nb_pt ALLOCATE Current
6. You can also avoid displaying this second harmonic line by reducing the peak threshold below its preset value Because the peak threshold level is used to determine which signals are to be displayed before amplitude corrections are applied the harmonic will be eliminated Refer to Defining Laser Line Peaks on page 2 13 In order to use the full wavelength range refer to To use the full wavelength range on page 2 9 2 7 Making Measurements Measuring Wavelength and Power To display peak wavelength and power 1 Connect the fiber optic cable to the front panel OPTICAL INPUT connector 2 To display the peak wavelength and power do one of the following e Press the green Preset key e Press Peak WL 3 To move the cursor to view other signals press e PREV WL to select next previous shorter wavelength e NEXT WL to select next longer wavelength e PEAK to signal with greatest power e PREV PK to select next lower power signal e NEXT PK to select next higher power signal To display multiple laser lines 1 Connect the fiber optic cable to the front panel OPTICAL INPUT connector 2 Press the green Preset key 3 Press List by WL to display the laser lines from the shortest wavelength to the longest wavelength 4 Press List by Power to display the laser lines in order of decreasing amplitudes To display average wavelength and total power e Press the Avg WL key 2 8 Making Measurem
7. 3 46 Programming Lists of Commands Table 3 7 Programming Commands 2 of 5 Command Description Code Codes S indicates a standard SCPI command indicates an instrument specific command CALCulate1 Subsystem CALCulate1 DATA Queries the uncorrected frequency spectrum data of the input signal S CALCulate1 TRANsform FREQuency POINts Sets and queries the number of points in the data set S CALCulate2 Subsystem CALCulate2 DATA Queries the corrected frequency spectrum data of the input signal S CALCulate2 PEXCursion Sets the peak excursion limit CALCulate2 POINts Queries the number of points in the data set CALCulate2 PTHReshold Sets the peak threshold limit CALCulate2 PWAVerage STATe Places the instrument in the average wavelength mode Data queries return the power weighted average frequency wavelength or wavenumber or total power CALCulate2 WLIMit STATe Limits input wavelength range of the HP 86120A CALCulate3 Subsystem CALCulate3 DATA Queries the data resulting from delta drift and signal to noise S measurements CALCulate3 DELTa POWer STATe Turns the delta power measurement mode on and off CALCulate3 DELTa REFerence FREQuency Selects the signal to be used as the reference forthe DELTa 1 calculations CALCulate3 DELTa REFerence POWer Queries the power level of the reference signal CALCulate3
8. Connector or insertion loss is one important performance characteristic of a lightwave connector Typical values are less than 0 5 dB of loss and sometimes as little as 0 1 dB of loss with high performance connectors Return loss is another important factor It is a measure of reflection the less reflection the better the larger the return loss the smaller the reflection The best physi cally contacting connectors have return losses better than 50 dB although 30 to 40 dB is more common 2 39 CAUTION Making Measurements Cleaning Connections for Accurate Measurements Visual inspection of fiber ends Although it is not necessary visual inspection of fiber ends can be helpful Contamina tion or imperfections on the cable end face can be detected as well as cracks or chips in the fiber itself Use a microscope 100X to 200X magnification to inspect the entire end face for contamination raised metal or dents in the metal as well as any other imper fections Inspect the fiber for cracks and chips Visible imperfections not touching the fiber core may not affect performance unless the imperfections keep the fibers from contacting To clean a non lensed connector Do not use any type of foam swab to clean optical fiber ends Foam swabs can leave filmy deposits on fiber ends that can degrade performance 1 Apply isopropyl alcohol to a clean lint free cotton swab or lens paper Cotton swabs can be used as long
9. DRIFt STATe Turns on and off the drift measurement calculation CALCulate3 DRIFt STATe ON OFF 1 0 Preset State off RST State off SCPI Compliance instrument specific When the drift mode is first turned on the current list of laser lines is placed into the reference All subsequent measurements take the new data subtract the reference data and display the differences in wavelengths and powers The CALC3 DATA query returns the power and frequency of the current measurement minus the power and frequency of the reference 4 47 Syntax Attribute Summary Description Syntax Programming Commands CALCulate3 Subsystem Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selectingmeasure ments POINts Queries the number of points in the data set CALCulate3 POINts Preset State unaffected by RST State unaffected by SCPI Compliance instrument specific Query Only The value returned is the number of points returned by the CALC3 DATA query SNR AUTO Selects the reference frequency value for measuring noise in the signal to noise calculation CALCulate3 SNR AUTO ON OFF 1 O Constant Description ON Selects internally generated reference frequency OFF Select
10. Queries the round trip path delay in the laser chip LENGth COHerence DELay Query Only The units of the returned value are in meters Programming Commands CALCulate1 Subsystem CALCulatel Subsystem Use the CALCulatel commands to query uncorrected frequency spectrum data In NORMAL measurement update mode 34 123 values are returned If the HP 86120A is set for FAST measurement update mode low resolution 4 268 values are returned The commands in this subsystem have the following command hierarchy CALCulatel DATA TRANsform FREQuency POINts 4 25 Syntax Attribute Summary Description Programming Commands CALCulate1 Subsystem DATA Queries uncorrected frequency spectrum data of the input laser line CALCulatel DATA Preset State not affected SCPI Compliance standard Query Only The returned values are in squared Watts linear units No amplitude or fre quency correction is applied to the values To obtain the logarithmic result multiply five times the logarithm of the returned values Be prepared to process a large amount of data when this query is sent The amount of data returned depends on the measurement update state of the instrument which can be set using the CALCulate1 TRANsform FRE Quency POINts command or the resolution argument of an instrument func tion Refer to Measurement Instructions on page 4 14 When NORMAL measurement update is specified o
11. User s Guide HP 86120A Multi Wavelength Meter LA eackaao HP Part No 86120 90012 Printed in USA November 1996 First Edition Copyright Hewlett Packard Company 1996 All Rights Reserved Reproduction adaptation or translation without prior written permission is prohibited except as allowed under copyright laws Hewlett Packard Company Lightwave Operations 1400 Fountaingrove Parkway Santa Rosa CA 95403 1799 USA 707 577 1400 Notice The information contained in this document is subject to change without notice Companies names and data used in examples herein are ficti tious unless otherwise noted Hewlett Packard makes no warranty of any kind with regard to this material including but not limited to the implied warran ties of merchantability and fitness for a particular purpose Hewlett Packard shall not be liable for errors contained herein or for incidental or consequen tial damages in connection with the furnishing performance or use of this material Restricted Rights Legend Use duplication or disclosure by the U S Gov ernment is subject to restrictions as set forth in subparagraph c 1 Gi of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 for DOD agencies and subparagraphs c 1 and c 2 of the Commercial Computer Software Restricted Rights clause at FAR 52 227 19 for other agencies il CAUTION WARNING Safety Symbols Safety Symbols The
12. 3 8 Programming Making Measurements Table 3 1 Commands for Capturing Data Desired Command to Configure Measurement Measurement partial listing Command to Query Data Wavelength nm CONFigure FETCh READ and MEASure MEASure ARRay POWer WAVelength Frequency THz CONFigure FETCh READ and MEASure MEASure ARRay POWer FREQuency Wavenumber m7 CONFigure FETCh READ and MEASure MEASure ARRay POWer WNUMber Coherence Length m CONFigure FETCh READ and MEASure FETCh READ or MEASure Power W dBm CONFigure FETCh READ and MEASure MEASure ARRay POWer Average Wavelength CALCulate2 PWAVerage STATe CALCulate2 DATA Wavenumber or Frequency Total Power W dBm CALCulate2 PWAVerage STATe CALCulate2 DATA Laser Line Separation CALCulate3 DELTa REFerence CALCulate3 DATA Laser Line Drift CALCulate3 DRIFt STATe CALCulate3 DATA Signal to Noise Ratio CALCulate3 SNR STATe CALCulate3 DATA Time Domain Data CALCulate1 TRANsform FREQuency POINts SENSe DATA Corrected Frequency Domain Data CALCulate1 TRANsform FREQuency POINts CALCulate2 DATA Uncorrected Frequency Domain CALCulate1 TRANsform FREQuency POINts CALCulate1 DATA Data 3 9 Programming Making Measurements Measurement instructions give quick results The easiest way to measure wavelength frequency power or coherence length is to use the MEASure comma
13. A fast update measurement mode is available for quicker measurement acquisi Uncorrected data buffer frequency domain data 64K 8K Ison Resolution argument of CALCulatel DATA FETCh READ or INITiate MEASure continuous time domain or single data HeNE measurement 128K Reference acquisition Laser SENSe DATA flom 3 6 Programming Making Measurements tion But because only 8 192 data values are collected in fast update measure ment mode the ability to resolve closely spaced signals is reduced After collecting the uncorrected data the HP 86120A searches the data for the first 100 peak responses Searching starts at 1700 nm and progresses towards 700 nm These peak values are then placed into the corrected data buffer Each peak value consists of an amplitude and wavelength measure ment Amplitude and wavelength correction factors are applied to this data For a listing of the programming commands including a cross reference to front panel keys refer to the following tables Table 3 7 Programming Commands on page 3 46 Table 3 8 Keys Versus Commands on page 3 51 CALCulate2 WLIMit SENSe CORRection ELEVation PTHreshold MEDium PEXCursion OFFSet MAGNitude Corrected data buffer 100 pairs of Peak A A and amplitude Display values DISPlay WINDow UNIT CALCulate2 DATA CONFigure POINts DISPlay MARKer PWAVerage CALCulate3 DELTa CALCu
14. Press SELECT Press SELECT anytime to select anew reference Press RESET anytime to turn off the delta calculation To measure flatness NO amp Press the front panel Preset key Press List by Power This lists the input signals by power with the largest response listed first Press the Delta On key Select A PWA Use the amp and softkeys to select the first laser line Press SELECT Since the largest power signal is the reference the relative power measurements for the other responses shows system flatness Making Measurements Measuring Laser Drift Measuring Laser Drift In this section you ll learn how the HP 86120A can be used to monitor drift changes to a laser s wavelength and amplitude over time Drift is measured simultaneously for every laser line that is identified at the input The HP 86120A keeps track of each laser line s initial current minimum and max imum values and displays their differences relative to itself This allows the HP 86120A to be used for laser transmitter evaluation burn in or develop ment In addition you can monitor system performance over time tempera ture or other condition The following display shows power and wavelength drift measured on five laser lines The DRIFT annotation item tells you that drift measurements are being performed The current relative drift values for wavelength and power are shown in items and respectively Item indicat
15. QUEStionable ENABle lt value gt lt imteger gt an interger from 0 to 65535 Preset State none RST State none SCPI Compliance standard The enable mask selects which conditions in the event register cause the sum mary bit in the status byte to be set If a bit in the enable mask is set true and the corresponding event occurs the summary bit bit 3 for the questionable status or bit 7 for the operation status in the status byte will be set 4 67 Example Query Response Syntax Query Response Attribute Summary Description Example Syntax Programming Commands STATus Subsystem OUTPUT 720 STATUS QUESTIONABLE ENABLE 1024 When queried the largest value that can be returned is 65535 This is because the most significant register bit cannot be set true OPERation QUEStionable EVENt Queries the contents of the questionable or operation event registers STATus OPERation QUEStionable EVENt 0 to 32767 Preset State none RST State none SCPI Compliance standard Query Only The response will be a number from 0 to 32767 indicating which bits are set Reading the register clears the register OUTPUT 720 STATUS OPERATION EVENT OPERation QUEStionable NTRansition Selects bits in the event register which can be set by negative transitions of the corresponding bits in the condition register STA
16. Specifications and Regulatory Information FC APC patchcord loss The effect of having loss in the FC APC patchcord 1 to 2 connector pair is to under mea sure the return loss by twice the FC APC patchcord 1 to 2 loss For example if this con nector pair loss is 0 5 dB then the actual return loss caused by the 14 6 dB Fresnel reflection is 15 6 dB but we enter 14 6 dB as an R value Then if the DUT return loss is exactly 40 dB below that of the 14 6 Fresnel reflection the optical return loss module will display 53 6 dB because the 0 5 dB connector pair loss seen twice is removed In reality the return loss is 54 6 dB exactly 40 dB below 14 6 dB better than that dis played 5 25 Equipment Procedure Servicing Testing Performance Test 5 Amplitude Accuracy and Linearity Amplitude linearityis performed using the following devices 1550 nm DFB lasers Optical attenuator HP 11896A Polarization Controller Optical power meter Polarization sensitivity To ensure measurement accuracy minimize the movement of any fiber optic cables dur ing this procedure Moving cables causes polarization changes which affect amplitude measurements 1 Turn on the laser and allow it to warm up 2 Connect the laser s output to the optical attenuator s input 3 Connect the optical attenuator s output to the polarization controller s optical input 4 Connect the polarization controller s optica
17. The noise power measurements use linear interpolation to estimate the noise power level at the signal of interest s wavelength 2 26 Making Measurements Measuring Signal to Noise Ratios Plaser line Automatic interpolation User entered wavelength When the signal to noise user function is selected the HP 86120A uses only one wavelength to measure the noise power for all signals This wavelength is set by the user and all signals are compared to the noise level at this wave length to determine their corresponding signal to noise ratios Noise bandwidth affects measurement When measuring noise power the HP 86120A must account for the noise bandwidth used during the measurement Because noise bandwidth varies with measurement bandwidth a wide bandwidth allows more noise to the HP 86120A s detector than a narrow bandwidth the HP 86120A normalizes all noise power measurements to a bandwidth of 1 nm The annotation 1 nmis displayed to show that the noise bandwidth is being normalized to a 1 nm bandwidth Repetitive data formats The HP 86120A signal to noise application works best when the laser being tested is not modulated or modulated with non repetitive data formats With repetitive data for mats such as PRBS data and SONET formats there is significant low frequency ampli tude modulation of the laser This modulation raises the noise floor of the HP 86120A significantly The signal to noise measured can be
18. WAI 4 13 warranty viii wave number 2 11 wavelength definition of 6 3 input range 2 2 peak 2 8 range 2 9 3 5 4 35 separation 2 18 specifications 6 6 WAVelength programming command 4 20 4 41 4 50 WDM flatness 2 19 system 2 18 white space characters 3 26 WL LIM softkey 1 14 2 9 WL REF softkey 2 28 A WL softkey 2 20 WL softkey 2 11 A WL PWR softkey 2 20 WLIMit programming command 4 35 WNUMber programming command 4 22 4 41 4 50 Index 7 Index Index 8
19. instrument specific A laser line is identified as a valid peak if its amplitude is greater than the peak excursion plus the amplitudes of the closest local minima on either side of the peak This command works in conjunction with the peak threshold setting Refer to PTHReshold on page 4 33 Changing the peak excursion limit causes the instrument to reprocess the current set of data Refer also to Defining Laser Line Peaks on page 2 13 The query response is the current value For example if the current value is set to 15 dB the following value is returned 15 Programming Commands CALCulate2 Subsystem Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrument Refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 for more information POINts Queries the number of points in the data set Syntax CALCulate2 POINts Attribute Summary Preset State unaffected RST State unaffected SCPI Compliance instrument specific Query Only Description This is the number of points that will be returned by the CALC2 DATA query Query Response For example if six laser lines are located 6 PTHReshold Sets the peak threshold limit used by the instrument to determine valid laser line peaks Syntax CALCulate2 PTHReshold lt integer gt MINimum MAXim
20. no softkeys are displayed Consult the documentation for your programming environment to determine which commands are used to put an instrument in the remote and local lock out modes These are not HP 86120A commands they control HP IB control lines and do not send any characters to the HP 86120A Initialize the instrument at start of every program It is good practice to initialize the instrument at the start of every program This ensures that the bus and all appropriate interfaces are in a known state HP BASIC provides a CLEAR command which clears the interface buffer and also resets the instrument s parser The parser is the program that reads the instructions that you send Whenever the instrument is under remote pro gramming control it should be in the single measurement acquisition mode This is automatically accomplished when the RST common command is used The RST command initializes the instrument to a preset state CLEAR 720 OUTPUT 720 RST 3 4 Programming Addressing and Initializing the Instrument Notice in the example above that the commands are sent to an instrument address of 720 This indicates address 20 on an interface with select code 7 Pressing the green Preset key does not change the HP IB address Set single acquisition mode An advantage of using the RST command is that it sets the HP 86120A into the single measurement acquisition mode Because the READ and MEASure data queries expect th
21. 12 OR Diff_diff 0 END 3 45 Programming Lists of Commands Lists of Commands Table 3 7 Programming Commands 1 of 5 Command Description Code Codes S indicates a standard SCPI command indicates an instrument specific command Common Commands CLS Clears all event registers and the error queue ESE Sets the bits in the standard event status enable register ESR Queries value standard event status register IDN Queries instrument model number and firmware version OPC Sets operation complete bit of the standard event status register RST Resets instrument SRE Sets bits in service request enable register STB Queries value of status byte TRG Triggers acquisition of measurement data TST Performs an instrument self test WAI Causes instrument to finish processing current command before continuing Measurement Instructions CONFigure Configures instrument for wavelength wavenumber frequency power and coherence length measurements FETCh Queries wavelength wavenumber frequency power and coherence length measurements that have already been captured MEASure Configures measures and queries wavelength wavenumber frequency power and coherence length measurements READ Measures and queries wavelength wavenumber frequency power and coherence length measurements
22. 15 dB ast state Measurement speed normal ast state Drift measurements off off Delta Measurements A power off off A wavelength off off reference signal position 700 nm 700 nm Signal to Noise Measurements measurement off off user frequency 193 4144 THz last state user wavelength 1550 nm in vacuum last state HP IB address not affected last state Power bar display on last state a The term last state refers to the last setti power was turned off ng that this parameter was in before the instrument 4 75 Programming Commands SYSTem Subsystem VERSion Queries the version of SCPI that the HP 86120A complies with Syntax SYSTem VERSion Attribute Summary Preset State none RST State none SCPI Compliance standard Query Only Description The SCPI version used in the HP 86120A is 1995 0 Table 4 9 SCPI Version Numbers SCPI Version Instrument Serial Prefix 1995 0 US3545 and above Programming Commands TRIGger Subsystem TRIGger Subsystem The SCPI definition defines the TRIGger subsystem to include ABORt ARM INITiate and TRIGger commands The HP 86120A has no ARM or TRIGger commands The commands in this subsystem have the following command hierarchy ABORt INITiate CONTinuous IMMediate 4 77 Syntax Attribute Summary Description Syntax Attribute Summary Description Programming Commands TRIGger Subsystem ABORt Hal
23. 3 7 Programming Commands 4 of 5 Command Description Code Codes S indicates a standard SCPI command indicates an instrument specific command HCOPy Subsystem HCOPy IMMediate Starts a printout S SENSe Subsystem SENSe CORRection ELEVation Sets the elevation value used by the instrument to compensate for air dispersion SENSe CORRection OFFSet MAGNitude Sets the power offset value used by the instrument S SENSe CORRection MEDium Sets the instrument to return the wavelength reading in a vacuum when the parameter is on Parameters are VAC and AIR SENSe DATA Queries the time domain samples of the input signal STATus Subsystem STATus OPERation QUEStionable CONDitio Returns the value for the condition register for the node S n STATus 0PERation QUEStionable EVENt Returns the value of the event register for the node S STATus 0PERation QUEStionable ENABle Sets the enable register S STATus 0PERation QUEStionable PTRansiti Sets the positive transition filter register S on STATus 0PERation QUEStionable NTRansit Sets the negative transition filter register S ion STATus PRESet Presets the enable registers for all status nodes S SYSTem Subsystem SYSTem ERRor Queries an error from the error queue S SYSTem HELP HEADers Queries an ASCII listing of all HP 86120A remote commands SYSTem PRESet Perfor
24. 4 61 STATus Subsystem 4 66 SYSTem Subsystem 4 71 TRIGger Subsystem 4 77 UNIT Subsystem 4 80 Servicing General Information 5 4 Electrostatic Discharge Information 5 12 Troubleshooting 5 14 Testing Performance 5 20 Replacing Instrument Assemblies 5 30 Replaceable Parts 5 43 Specifications and Regulatory Information Definition of Terms 6 3 Specifications 6 6 Regulatory Information 6 10 Reference Instrument Preset Conditions 7 3 Menu Maps 7 5 Contents 2 Contents Error Messages 7 12 Front Panel Fiber Optic Adapters 7 18 AC Line Power Cords 7 19 Hewlett Packard Sales and Service Offices 7 20 Contents 3 Contents Contents 4 Getting Started WARNING CAUTION CAUTION CAUTION Getting Started Getting Started Getting Started The instructions in this chapter show you how to install your HP 86120A You should be able to finish these procedures in about ten to twenty minutes After you ve completed this chapter continue with Chapter 2 Making Mea surements Refer to Chapter 6 Specifications and Regulatory Information for informa tion on operating conditions such as temperature If you should ever need to clean the cabinet use a damp cloth only This is a Safety Class I 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 inter
25. 5 MHz Burst rate 4 per second Burst duration 15 ms Amplitude 1V p p Voltage at lowest point OV 6 If there is no signal present replace the Al assembly 7 Disconnect the SMB cable from A5J12 and connect the cable to the oscilloscope This is the signal from the signal detector and it should be close to OV dc 8 Connect a single frequency laser such as a DFB laser to the instrument s front panel OPTICAL INPUT connector 9 Set the laser s power to 1 mW 0 dBm 10 Observe the signal on the oscilloscope It should consist of sine wave bursts Servicing Troubleshooting with the following approximate characteristics Burst rate 4 per second Burst duration 15 ms Amplitude 1V p p Voltage at lowest point 0V The signal s amplitude level varies linearly with the laser s power 11 If there is no signal present replace the Al assembly 12 Reconnect the cables to A5J11 and A5J12 To check the line power fuse 1 Locate the line input connector on the instrument s rear panel 2 Disconnect the line power cable if it is connected 3 Use a small flat blade screwdriver to open the pull out fuse drawer The recommended fuse is an IEC 127 5x20 mm 6 3A 250 V HP part num ber 2110 0703 Notice that an extra fuse is provided in a drawer located on the fuse holder WARNING For continued protection against fire hazard replace line fuse only with same type and ratings type T 6 3A 250V for 10
26. 51 7 16 Setup key 1 14 2 9 3 5 menu map 7 11 shipping procedure 1 16 short form commands 3 24 signal to noise measurements 2 25 noise calculation 2 25 4 48 ratios iv specification 6 8 Single key 2 11 2 14 softkey equivalent commands 3 51 menus 7 5 SONET 2 27 2 32 specifications 6 2 6 6 definition of terms 6 2 operating 6 9 spurious signals 2 7 suppressing 2 13 SRE 4 10 standard air 1 13 2 34 event status register 4 6 SCPI commands 3 23 STATe programming command 4 34 4 39 4 42 4 43 4 44 4 45 4 46 4 47 4 51 4 56 status byte register 4 11 reporting 3 16 STATus subsystem 4 66 STB 4 11 STD AIR annotation 2 34 softkey 1 13 2 35 subsystems 3 24 syntax rules 3 23 3 28 SYSTem subsystem 4 71 T tamper resistant label 5 7 Index Tempo subroutine 3 31 erahertz 2 11 THRSHLD softkey 2 16 THZ softkey 2 11 ools for servicing 5 4 otal power iv 2 7 maximum measurable 2 33 measuring 2 6 ransient data 3 12 TRG 4 12 rigger ignore 7 16 TRIGger subsystem 4 77 roubleshooting 5 2 TST 4 12 NIT subsystem 4 80 nits of measure 2 10 ITS softkey 2 11 p arrow softkey 2 5 PDATE softkey 2 12 ppercase letters 3 25 USER softkey 2 28 USER WL softkey 2 28 UW softkey 2 11 Co Ce G c V VAC annotation 2 34 VACuum programming command 4 63 VACUUM softkey 1 13 2 35 vacuum measurements in 2 34 VERSion programming command 4 76 W
27. 7 3 General SCPI Error Messages 2 of 3 Error Number Desription 158 String data not allowed 161 Invalid block data 168 Block data not allowed 170 Expression error 171 Invalid expression 178 Expression data not allowed 200 Execution error 211 Trigger ignored Caused by sending the TRG command when the instrument is already taking a measurement or when the instrument is in continuous measurement mode 213 Init ignored Caused by sending an INIT IMM READ or MEASure command while a measurement is already in progress or while the instrument is in continuous measurement mode 221 Settings conflict Caused by trying to set the instrument to a state that is not allowed For example turning on drift maximum and drift minimum state simultaneously or turning on SNR state while drift or delta state is on 222 Data out of range 223 Too much data 224 Illegal parameter value 230 Data corrupt or stale Caused by trying to query measurement data immediately after a RST command For example sending RST FETCh or sending RST CALC2 DATA pow 232 Data questionable Caused by sending a resolution value in one of the measurement functions that is outside the intrument s range 273 Illegal macro label 7 16 Table 7 3 General SCPI Error Mes
28. A5J7 and A5J8 15V 2 Ifno voltages are detected check that the ac line voltage is present at the A2 Power Supply Board Assembly s 3 pin connector Measure the line voltage across the white gray red wire and the gray wire e Ifthe ac line voltage is present check the 5A fuse on the A2 Power Sup ply Board Assembly e Ifno voltage is present check the 6 3A fuse in the rear panel s line mod ule FL1 Refer to To check the line power fuse on page 5 19 3 Measure the 5V supply to the A4 assembly at A5J1 4 Measure the 5V supply to the A6 Front Panel Assembly at A5J2 5 17 Servicing Troubleshooting To check the Al Optical Block Assembly This procedure tests the output from the two photodetectors in the Al assem bly 1 Measure the voltage at A5J7 pin 1 It should measure 13V This voltage is for the Al assembly s reference laser It is generated from 15V by a voltage dropping resistor 2 Measure the 15V 5V and 15V supplies at A5J5 These voltages power the Al assembly s encoder 3 Measure the 15V and 15V supplies at A5J10 These voltages power the Al assembly s detectors 4 Disconnect any input signal from the instrument s OPTICAL INPUT connector 5 Disconnect the SMB cable from A5J11 and connect the cable to an oscilloscope This is the signal from the reference detector and it should consist of sine wave bursts with the following approximate characteristics Frequency
29. HP 86120A offers an extensive set of HP IB programming commands These commands allow you to perform automated measurements on manufac turing production lines and remote sites Chapters 3 and 4 provide all the information you ll need to know in order to program the HP 86120A Display wavelengths as if measured in vacuum or standard air Although all measurements are made in air displayed results are corrected for air dispersion to accurately show wavelength values in vacuum or in standard air To ensure accurate wavelength measurements make sure that you enter the elevation from which you will be making measurements as described in Chapter 1 Getting Started Measurement accuracy it s up to you Fiber optic connectors are easily damaged when connected to dirty or damaged cables and accessories The HP 86120A s front panel INPUT connector is 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 HP 86120A refer to Cleaning Connec tions for Accurate Measurements on page 2 38 WARNING WARNING General Safety Considerations General Safety Considerations This product has been designed and tested in accordance with IEC Publica tion 1010 Safety Requirements for Electronic Measuring Apparatus and has been supplied in a safe condition The instruction d
30. Mwm OUTPUT Mwm ESE IVAL 00110100 2 SUBEND Identity DEF FNIdentity COM Instrument Mwm DIM Identity 50 IdentityS OUTPUT Mwm RST OUTPUT Mwm OPC F ER Mwm Opc_done OUTPU wm IDN ER Mwm Identity URN Identity gt RE FNEND Cmd_opc SUB Cmd_opc Set_cmd COM Instrument Mwmd OUTPUT Mwm Set_cmd OUTPUT Mwm OPC ENTER Mwm Opc_dones SUBEND 3 43 Programming Example Programs Example 6 Increase a source s wavelength accuracy This example program uses the HP 86120A to increase the absolute wave length accuracy of HP 8167A HP 8168B and HP 8168C Tunable Laser Sources Essentially the HP 86120A s accuracy is transferred to the tunable laser source The absolute accuracy of the tunable laser source is increased from lt 0 1 nm to lt 0 005 nm which is the HP 86120A s absolute accuracy at 1550 nm In order to run this program the tunable laser source s firmware must support the automatic alignment command WAVEACT The program uses the following measurement algorithm Identify and initialize the HP 86120A and tunable laser source Ask user for desired wavelength Set wavelength of tunable laser source Turn tunable laser source s output on Enter loop Measure wavelength Compare wavelength to desired wavelength Realign tunable laser source s wavelength
31. Observe the following warning about correct wire attachment The wire col or codes in the figure refer to the following cable colors 54 green yellow 98 white gray 918 white brown gray Be sure to solder the wires to FL1 in the correct positions as shown in the following figure Failure to attach these wires correctly could result in damage to the instrument and injury to the user 54 inrear 91 8 98 Servicing Replaceable Parts Replaceable Parts In this section you ll find figures that identify each mechanical and electrical assembly in the instrument A Hewlett Packard part number is provided for each available part The following identification figures are provided Table 5 7 Major Assemblies on page 5 46 Table 5 8 Cable Assemblies on page 5 48 Table 5 9 Front Panel Parts on page 5 50 Table 5 10 Rear Panel Parts on page 5 52 Table 5 11 Top View Parts on page 5 54 Table 5 12 Bottom View Parts on page 5 56 Table 5 13 Side View Parts on page 5 58 Table 5 14 Instrument Cover Parts on page 5 60 Part ordering information To order an assembly or mechanical part quote the Hewlett Packard part number and indicate the quantity required To order a part that is not listed include the following information with the order HP 86120A model number HP 86120A serial number Description of where the part is located what it looks like and its fu
32. PUT Mwm OPC ER Mwm Opc_done OU PUT Mwm IDN ER Mwm Identity RE FNEND URN Identity EN PRINT AND NOT BIT Cme 4 IVAL 00110100 2 Err_msg AND NOT BIT Cme 5 3 40 Cmd_ope SUB Cmd_opc Set_cmd COM Instrument Mwm OU OU PU PU EN SUBI END Mwm Set_cmd Mwm OPC ER Mwm Opc_done Programming Example Programs 3 41 Programming Example Programs Example 5 Measure signal to noise ratio This program measures signal to noise ratios on a Fabry Perot laser It mea sures the ratio for each line using commands from the CALCulate3 subsystem Refer to the introduction to this section for a description of each subroutine that is contained in this program COM Instrument Mwm ASSIGN Mwm TO 720 DIM Key 1 N ERROR GOTO Error_msg et_ese USING 37A 33A Multi Wavelength Meter Identity is FNIdentity EOUT 7 5 CALL Err_mngmt d opc RST RINT sO TIM Ho PU ER LOCA AOQO Zc D Mwm MEAS ARR POW WAV wm USING K Nb_pt zZ ER PU ER TOE an E Current_wl 1 Nb_pt wm USING K Current_wl Mwm FETC ARR POW wm USING K Nb_pt E Current_pwr 1 Nb_pt ALLOCA F ER Z wm USING K Current_pwr Tur
33. Replaceable Parts Table 5 8 Cable Assemblies Reference HP Part Description Designator Number w1 08169 67608 Input Fiber Optic Cable 81685 67688 Input Fiber Optic Cable Option 022 angled input fiber w2 86120 60019 Front Panel Ribbon Cable W3 86120 60023 Display Power Cable W4 8120 5020 SMB Cable 260 mm long w5 8120 5021 SMB Cable 310 mm long W6 86120 60024 Detector Bias Cable W7 86120 60020 Main Bus Cable W8 Part of B1 Not separately orderable wg 86120 60018 Digital Signal Processing Ribbon Cable W10 Control Cable for A1 Assembly Can not be ordered separately W11 Control Cable for A1 Assembly Can not be ordered separately W12 86120 60021 Line Switch Cable includes FL1 W13 86120 60022 Power Harness Cable 5 48 Servicing Replaceable Parts w1 W12 Top View 5 49 rpcable W3 W2 w1 W4 W11 W10 Bottom View DNA W13 0090900 589 a 050 0 S080 0 080 onggo 9p W5 W6 W13 W7 w8 w9 Servicing Replaceable Parts Table 5 9 Front Panel Parts
34. Replacing Instrument Assemblies To replace the A3 High Voltage Power Supply Assembly To prevent shock do not cut or damage the high voltage cables when removing the cable ties in the following step 1 Remove the instrument cover as described in To remove the instrument cover on page 5 31 2 Cut and remove the three cable ties that secure the high voltage connector to the side panel 3 Unplug the high voltage connector as described in the following warning message To prevent shock carefully unplug the laser s high voltage connector as described in the next step This cable remains energized long after the instrument has been disconnected from the power source Immediately after unplugging the connector ground the two contacts of the male connector simultaneously on the side of the instrument to discharge the plasma tube 4 Unplug the high voltage connector shown in the following figure Immediately after unplugging the connector ground the two contacts of the male connector simultaneously on the side of the instrument to discharge the plasma tube 5 37 Servicing Replacing Instrument Assemblies Top View s P ai High Voltage Connector lec 5 Place the instrument on its left side highvott 6 Cut and remove the cable ties that secure the high voltage connector cable to the fan assembly 7 Cut and remove the cable ties that secure cab
35. Servicing Replacing Instrument Assemblies emove the instrument cover as described in To remove the instrumen R th t t d bed in T th t t cover on page 5 31 Disconnect fiber optic cable W1 from the A1 assembly Use caution to avoid touching the cable s ferrule tip against the connector body Cable w1 Clips optblk1 Cover the free end of the cable W1 and the connector on the Al assembly to protect them from damage WARNING To prevent shock do not cut or damage the high voltage cables when removing the cable ties in the following step 4 Cut and remove the three cable ties that secure the high voltage connector to the side panel These clips are identified in the figure above Remove the two SMA cables and two twisted wire cables that attach to the A1A2 assembly shown in the following figure 5 33 WARNING Servicing Replacing Instrument Assemblies 99 oso oD A1A2 optblkz To prevent shock carefully unplug the laser s high voltage connector as described in the next step This cable remains energized long after the instrument has been disconnected from the power source Immediately after unplugging the connector ground the two contacts of the male connector simultaneously on the
36. Started Returning the Instrument for Service Making Measurements CAUTION Making Measurements Making Measurements Making Measurements In this chapter you ll learn how to make a variety of fast accurate measure ments As you perform these measurements keep in mind the following points Do 700 nm to 1650 nm maximum input wavelength range The range is normally limited from 1200 nm to 1650 nm To use the full range refer to Measuring lasers between 700 nm and 1200 nm on page 2 7 and to To use the full wavelength range on page 2 9 10 dBm maximum total displayed input power Laser linewidths assumed to be less than 10 GHz If you change the elevation where you will be using your HP 86120A refer to Calibrating Measurements on page 2 34 Press the green Preset key to return the HP 86120A to its default state not exceed 18 dBm source power The HP 86120A s input circuitry can be damaged when total input power exceeds 18 dBm You can measure power levels that are greater by adding attenuation and entering a power offset as described in To measure total power exceeding 10 dBm on page 2 33 2 2 Contents Making Measurements Making Measurements Measuring Wavelength and Power 2 4 To display peak wavelength and power 2 8 To display multiple laser lines 2 8 To display average wavelength and total power 2 8 To use the full wavelength range 2 9 To control the power bar 2 9 Changin
37. To check the Al Optical Block Assembly on page 5 18 3 Ifthe instrument does not display a signal s power or wavelength the A4 or A5 assembly is faulty If the display is blank 1 Measure the 5 2V supply to the A6A1 Display Assembly at A5J2 2 Ifthe voltage is incorrect refer to To check the power supply voltages on page 5 17 3 Check the W2 ribbon cable connections If random symbols are displayed 1 Test the power supply voltages as described in To check the power supply voltages on page 5 17 2 Ifthe voltages are correct the A5 Main Board Assembly is probably faulty If the front panel keys don t work e Ifonly one key does not function there is probably a bad contact Replace the A6 Front Panel Assembly e If several keys do not function suspect ribbon cable W2 or the A5 Main Board Assembly Servicing Troubleshooting If the fan doesn t run e Measure the 12V supply at A5J8 pin 4 Power for the fan B1 is supplied through two resistors on the A5 assembly which drop the 15V supply to 12V To check the power supply voltages 1 Measure the following voltages On the following wires located at the A2 Power Supply Board Assembly s 13 pin connector e Yellow wires 5 2V e Red wires 15V e Violet wire 15V e Black wires ground On the A5 Main Board Assembly e A5J1 pins 13 and 15 5 2V e A5J1 pins 1 and 3 15V e Large resistor s lead located next to
38. USING length is OE 9 1 INT USING 17A 2D 6A line Ertl asx nm Delta Pwr m we ta_pwr I dB T nm Absolute 1 Delta_pwr 1 dBm USING ength is ute line level is 6A 2D 17A M4 Error_msg The program is aborted due to INT ngmt SUB Instrument Mwmt Err_msg 255 I C EGER Cme AR Mwm RE UHH EAT Suben Set OU EN OU EN Mwm ESR Mwm Cme Mwm Err_msg IF NO Err_msg 0 d SUBEND SUB COM Ins OUTPUT SUBI EN Ident COM Ins DIM Iden Identity S Set_es trument Mwm wm ESE D NOT POS Cmd_msg makes t POS Err_msg 0 UNTIL NOT BIT Cme 2 AND POS ine leve 6A 2D 17A M4D 3D 31A S2D 2D 4A Line Delta_wl I NOT I 1 Delta_wl1 1 lis ee De Delta_pwr I NOT 4D 3D 23A 2D 6A S2D 2D 3A Delta Wl SYST ERR puts D 3D 31A S2D 2D 4A Line Delta_wl 1 Delta_wl Nb_pt 1 0E 9 Delta_pwr 1 Delta_pwr Nb_pt dBm Err_mngmt OPTIONAL Cmd_msg Err_msg 0 he following error Delta_wl I 1 NOT I 1 Delta_wl I to line is NOT I 1 Delta_pwr I 1 tep nm ERRMS This THEN PRINT THI D ity DEF FNIdentity trument Mwm tity 33 sau OU PUT Mwm RST OU
39. Wal A M C JC eee JD 2 Ifthe HP 86120A fails to turn on properly consider the following possibilities e Is the line fuse good e Does the line socket have power e Is it plugged into the proper ac power source If the instrument still fails return it to Hewlett Packard for repair Refer to Returning the Instrument for Service on page 1 15 Getting Started Step 5 Turn on the HP 86120A Instrument firmware version When the instrument is first turned on the display briefly shows the instrument s firm ware version number In the unlikely event that you have a problem with the HP 86120A you may need to indicate this number when communicating with Hewlett Packard There is no output laser aperture The HP 86120A does not have an output laser aperture However light less than 1 nw escapes out of the front panel OPTICAL INPUT connector Operator maintenance or pre cautions are not necessary to maintain safety No controls adjustments or performance of procedures result in hazardous radiation exposure Input Connector inptconr 1 11 Getting Started Step 6 Enter Your Elevation Step 6 Enter Your Elevation In order for your HP 86120A to accurately measure wavelengths and meet its published specifications you must enter the elevation where you will be per forming your measurements 1 Press the Setup key 2 Press the CAL softkey 3 Press ELEV 4 Use the and sof
40. are applied to the current displayed measurements even if the instrument is in the Single measurement mode 15 dB peak excursion 10 dB peak threshold Wavelength wavlth15 2 14 Power dBm 10 20 30 50 Making Measurements Defining Laser Line Peaks The following figure shows the same laser lines as the previous figure but the peak excursion value has been changed from 15 to 3 dB Four laser lines are now identified with responses and identified as two distinct laser lines Limiting the input wavelength range The HP 86120A s preset condition limits the wavelength measurement range from 1200 nm to 1650 nm You can expand the wavelength range to cover the entire 700 nm to 1650 nm range Although wavelength range limiting reduces the number of laser lines found its main purpose is to eliminate the identifica tion of second harmonic distortion products as described in the following side bar To set the wavelength range refer to To use the full wavelength range on page 2 9 3 dB peak excursion tod 10 dB peak threshold Wavelength wavlth3 2 15 Making Measurements Defining Laser Line Peaks Distortion caused by low power laser lines Low power laser lines power level near the HP 86120A s specified sensitivity may be accompanied by second harmonic or other distortion For example a low power laser line at 1550 nm has a second harmonic line at 775 nm If this second harmonic
41. are separated by the comma character Determine the number of data points When a FETCh READ or MEASure command is used with ARRay speci fied the first returned value indicates the total number of measurement val ues returned in the query If you use the CALCulatel DATA CALCulate2 DATA or CALCulate3 DATA queries to query data send the POINts query first to determine the number of values returned in the string The string does not contain a first value which specifies the string length This is shown in the fol lowing example OUTPUT 720 CALCulatel POINts ER 720 Length PUT 720 CALCulatel DATA ER 720 Result O Z2q24q Data can be corrected for elevation and vacuum Normally the HP 86120A provides measurement values calculated for condi tions in air at sea level Use the SENSe CORRection ELEVation command to compensate for air dispersion Altitudes up to 5000 meters can be entered Use the SENSe CORRection MEDium command to switch to readings in a vacuum Amplitude units The default amplitude units are dBm If you need measurements in watts use the UNIT POWer command When the HP 86120A is turned on the amplitude units are automatically set to the units used before the instrument was last turned off Programming Monitoring the Instrument Monitoring the Instrument Almost every program that you write will need to monitor the HP 86120A for its op
42. as no cotton fibers remain on the fiber end after cleaning 2 Before cleaning the fiber end clean the ferrules and other parts of the connector 3 Apply isopropyl alcohol to a new clean lint free cotton swab or lens paper 4 Clean the fiber end with the swab or lens paper Move the swab or lens paper back and forth across the fiber end several times Some amount of wiping or mild scrubbing of the fiber end can help remove particles when application of alcohol alone will not remove them This tech nique can remove or displace particles smaller than one micron 5 Immediately dry the fiber end with a clean dry lint free cotton swab or lens paper 6 Blow across the connector end face from a distance of 6 to 8 inches using filtered dry compressed air Aim the compressed air at a shallow angle to the fiber end face Nitrogen gas or compressed dust remover can also be used 2 40 CAUTION CAUTION Making Measurements Cleaning Connections for Accurate Measurements Do not shake tip or invert compressed air canisters because this releases particles in the can into the air Refer to instructions provided on the compressed air canister 7 As soon as the connector is dry connect or cover it for later use To clean an adapter 1 Apply isopropyl alcohol to a clean foam swab Cotton swabs can be used as long as no cotton fibers remain after cleaning The foam swabs listed in this section s introducti
43. cleared by sending the ESR query The value returned is the total bit weights of all of the bits that are set at the present time 3 20 Programming Monitoring the Instrument Enabling register bits with masks Several masks are available which you can use to enable or disable individual bits in each register For example you can disable the Hardcopy bit in the OPERation Status Register so that even though it goes high it can never set the summary bit in the status byte high Use the SRE common command to set or query the mask for the Status Byte Register The masks for the OPERation Status and QUEStionable Status registers are set and queried using the STATus subsystem s ENABle commands Use the ESE common command to set or query the mask for the Standard Event Status Register The CLS common command clears all event registers and all queues except the output queue If CLS is sent immediately following a program message terminator the output queue is also cleared In addition the request for the OPC bit is also cleared For example suppose your application requires an interrupt whenever any type of error occurs The error related bits in the Standard Event Status Reg ister are bits 2 through 5 The sum of the decimal weights of these bits is 60 Therefore you can enable any of these bits to generate the summary bit by sending the ESE 60 command Whenever an error occurs it sets one of these bits in th
44. discussed at this time This will help the HP service office repair and return your instrument as quickly as possible 1 15 CAUTION CAUTION Getting Started Returning the Instrument for Service Preparing the instrument for shipping 1 Write a complete description of the failure and attach it to the instrument Include any specific performance details related to the problem The following information should be returned with the instrument Type of service required Date instrument was returned for repair Description of the problem e Whether problem is constant or intermittent Whether instrument is temperature sensitive Whether instrument is vibration sensitive Instrument settings required to reproduce the problem Error codes e Performance data Company name and return address Name and phone number of technical contact person Model number of returned instrument Full serial number of returned instrument List of any accessories returned with instrument 2 Cover all front or rear panel connectors that were originally covered when you first received the instrument Cover electrical connectors to protect sensitive components from electrostatic damage Cover optical connectors to protect them from damage due to physical contact or dust Instrument damage can result from using packaging materials other than the original materials Never use styrene pellets as packaging material They do not adequately cushi
45. entry error queue The queue is a first in first out buffer Repeatedly sending the query SYSTEM ERROR returns the error numbers and descriptions in the order in which they occur until the queue is empty Any further queries returns 0 No errors until another error occurs For a complete list of error messages refer to Error Messages on page 7 12 lt value gt lt string gt lt value gt is an integer lt string gt is the text of the error message The following is an example of a response 113 Undefined header DIM Error 250 OUTPUT 720 SYSTEM ERROR ENTER 720 Error PRINT Error 4 72 Syntax Attribute Summary Description Programming Commands SYSTem Subsystem HELP HEADers Queries a listing of all the remote programming commands available for the HP 86120A SYSTem HELP HEADers Preset State none RST State none SCPI Compliance instrument specific Query Only The returned ASCII string of commands is in the IEEE 488 2 arbitrary block data format The first line indicates the total number of bytes returned to the computer That is the character is followed by one digit which indicates how many of the following digits convey the byte count The next digits give the actual byte count For example in the listing below 4010 bytes are indicated in the file Each command in the listing is separated by a linefeed char
46. in subsequent signal to noise calculations 4 49 Syntax Attribute Summary Description Syntax Programming Commands CALCulate3 Subsystem The default units for the lt real gt parameter is Hz SNR REFerence WAVelength Sets the wavelength used for the noise measurement reference in the signal to noise calculation CALCulate3 SNR REFerence WAVelength lt real gt MINimum MAXyimum lt real gt is a wavelength value that is within the following limits Constant Description MINimum 700 0 nm MAXimum 1650 0 nm Preset State unaffected by RST State 1550 0 nm in a vacuum SCPI Compliance instrument specific After entering this value use the SNR AUTO command to configure the instrument to use this value in subsequent signal to noise calculations The number entered is converted internally to the corresponding frequency The default units for the lt real gt parameter is meters SNR REFerence WNUMber Sets the wave number used for the noise measurement reference in the signal to noise calculation CALCulate3 SNR REFerence WNUMber lt real gt MINimum MAXimum lt real gt is a wave number value that is within the following limits Attribute Summary Description Syntax Attribute Summary Programming Commands CALCulate3 Subsystem Constant Description MINimum 6060 1650 nm MAXimum 14286 700 nm Preset State unaffected by RST State 1550 0 nm in
47. is compared to the absolute power of the noise at the carrier wave length See the following figure The noise power at the carrier must be deter mined by interpolation because the carrier in most cases can not or should not be turned off You can select one of two methods used to determine the wavelength where the noise is measured automatic interpolation or a user entered wavelength In the figure above notice that S N AUTO is displayed to indicate that automatic interpolation is selected Making Measurements Measuring Signal to Noise Ratios Plaser line Interpolated Noise value at noise value user entered using automatic wavelength mode peak Location of noise measurements Automatic interpolation When the signal to noise auto function is selected the HP 86120A first determines the proximity of any adjacent signal If the next closest signal is lt 200 GHz approximately 1 6 nm at 1550 nm away from the signal of interest then the noise power is measured half way between the two channels and an equal distance to the other side of the signal of interest See points Ph and Pag in the following figure If the closest signal is more than 200 GHz from the signal of interest or if there is no other signals present then the noise power is measured at 100 GHz on either side of the signal of interest The two measured noise power levels are then averaged to estimate the noise power level at the signal wavelength
48. loss or better making a wet connection will probably not improve and can degrade performance Hewlett Packard strongly recommends that index matching compounds not be applied to their instruments and accessories Some compounds such as gels may be difficult to remove and can contain damaging particulates If you think the use of such compounds is necessary refer to the compound manufacturer for information on application and cleaning procedures 2 38 Making Measurements Cleaning Connections for Accurate Measurements Table 2 2 Cleaning Accessories Item HP Part Number Isopropyl alcohol 8500 5344 Cotton swabs 8520 0023 Small foam swabs 9300 1223 Compressed dust remover non residue 8500 5262 Table 2 3 Dust Caps Provided with Lightwave Instruments Item HP Part Number Laser shutter cap 08145 64521 FC PC dust cap 08154 44102 Biconic dust cap 08154 44105 DIN dust cap 5040 9364 HMS10 HP dust cap 5040 9361 ST dust cap 5040 9366 Inspecting Fiber Optic Cables Consistent measurements with your lightwave equipment are a good indica tion that you have good connections However you may wish to know the insertion loss and or return loss of your lightwave cables or accessories If you test your cables and accessories for insertion loss and return loss upon receipt and retain the measured data for comparison you will be able to tell in the future if any degradation has occurred
49. number is returned Preset State not affected SCPI Compliance standard Query Only Use the CALC2 POIN query to determine the number of points the CALC2 DATA query will return The following string is a typical example of the first few returned values returned when WAVelength is specified 1 54488600E 006 1 54649100E 006 1 54808300E 006 1 54969600E 006 1 55131200E 006 1 55293000E 006 This next string resulted by specifying the WNUMber argument 6 47296600E 005 6 46625000E 005 6 45959900E 005 6 45287500 E 005 6 44615500E 005 6 43943900E 005 Notice that only measurement values are returned to the computer There is no first value that indicates the number of values contained in the string as there is for example with the FETCh READ and MEASure commands 4 31 Syntax Attribute Summary Description Programming Commands CALCulate2 Subsystem When there is no input signal the POWer query returns 200 dBm the WAVe length query returns 100 nm 1 0E 7 PEXCursion Sets the peak excursion limit used by the HP 86120A to determine valid laser line peaks CALCulate2 PEXCursion lt integer gt MINimum MAXimum DEFault lt imteger gt represents logarithmic units in dB Valid range is 1 to 30 dB Constant Description MINimum 1 dB MAXimum 30 dB DEFault 15 dB Non sequential command Preset State 15 dB RST State 15 dB SCPI Compliance
50. off and then on does not change these set tings Making Measurements Defining Laser Line Peaks If too many lines are identified If the following message is displayed too many laser lines have been identified E15 MAX NUMB The maximum number of laser lines that the instrument can measure is 100 If this mes sage appears decrease the peak threshold value or increase the peak excursion value ER OF SIGNALS FOUND 2 17 Making Measurements Measuring Laser Separation Measuring Laser Separation It is often important to measure the wavelength and power separation between multiple laser lines This is especially true in wavelength division multiplexed WDM systems where channel spacing must be adhered to The HP 86120A can display the wavelength and amplitude of any laser line relative to another In fact the following types of relative measurements can be made compared to the reference e Relative wavelength absolute power e Relative power absolute wavelength e Relative wavelength and power For example suppose that you want to measure separation on a system hav ing the spectrum shown in the following figure Reference 1541 747 nm 5 46 dBm 2 606 nm 1 302 nm 7 26 dB 1 98 dB 1 300 nm 2 596 nm 2 42 dB 4 41 dB peaks 2 18 Making Measurements Measuring Laser Separation The HP 86120A displays separation on this spectrum as shown in the follow ing figure Notice that the
51. on ordering static safe accessories These techniques for a static safe work station should not be used when working on circuitry with a voltage potential greater than 500 volts Reducing ESD Damage The following suggestions may help reduce ESD damage that occurs during testing and servicing operations e Personnel should be grounded with a resistor isolated wrist strap before re moving any assembly from the unit e Besure allinstruments are properly earth grounded to prevent a buildup of static charge Table 5 5 Static Safe Accessories HP Part Number Description 9300 0797 3M static control mat 0 6 m x 1 2 m 2 ftx 4 ft and 4 6 cm 15 ft ground wire The wrist strap and wrist strap cord are not included They must be ordered separately 9300 0980 Wrist strap cord 1 5 m 5 ft 9300 1383 Wrist strap color black stainless steel without cord has four adjustable links and a 7 mm post type connection 9300 1169 ESD heel strap reusable 6 to 12 months 5 13 WARNING WARNING Servicing Troubleshooting Troubleshooting The opening of covers or removal of parts is likely to expose dangerous voltages Disconnect the instrument from all voltage sources while it is being opened The power cord is connected to internal capacitors that may remain live for five seconds after disconnecting the plug from its power supply The A2 Power Supply Board Assembly generates four volta
52. queue by reading its contents sending the CLS com mand or by cycling the instrument s power The error queue is first in first out If the error queue overflows the last error in the queue is replaced with error 350 Queue overflow Any time the queue overflows the least recent errors remain in the queue and the most recent error is discarded The length of the instrument s error queue is 30 29 positions for the error messages and 1 position for the Queue overflow mes sage The error queue is read with the SYSTEM ERROR query Executing this query reads and removes the oldest error from the head of the queue which opens a position at the tail of the queue for a new error When all the errors have been read from the queue subsequent error queries return 0 No error For more information on reading the error queue refer to ERRor on page 4 72 For a list of errors messages refer to Error Messages on page 7 12 3 22 Programming Reviewing SCPI Syntax Rules Reviewing SCPI Syntax Rules The HP 86120A s programming commands comply with the SCPI standard In this section you ll learn the correct syntax for forming and sending HP 86120A command strings For more detailed information regarding the HP IB the IEEE 488 2 standard or the SCPI standard refer to the following books Hewlett Packard Company Tutorial Description of Hewlett Packard In terface Bus 1987 Hewlett Packard Co
53. shortest to longest wavelengths In either mode the HP 86120A can measure up to 100 laser lines simultaneously Displayed Laser Line has the Measurement Greatest Power Wavelength Power Acquisition N 7 Number of PEAK x Laser Lines ae Found 1551 314nn 3 P dem E GIES WAL Power Offset Power Br T EES faa H Applied C soe evation Calibration peakwl2 Display after Peak WL key pressed 2 4 Making Measurements Measuring Wavelength and Power Peak WL mode displays one signal When Peak WL is pressed the display shows the largest amplitude line in the spectrum The word PEAK is shown on the screen If multiple laser lines are present at the input the number of lines located will be shown along the right side of the screen In addition to the digital readouts there is a power bar It provides a conve nient analog meter movement for tuning laser power Although the Peak WL mode shows one signal at a time softkeys are provided that allow you to scroll through and display all the measured laser lines You can scroll through the list according to the wavelengths or powers measured List by WL or Power modes display multiple lines simultaneously In the list by wavelength or list by power modes the measurements of five laser lines can be displayed at any one time Use the amp and softkeys to move the cursor through the list of signals the list can contain up to 100 entries Press the SEL
54. side of the instrument to discharge the plasma tube 6 Unplug the high voltage connector shown in the following figure Immediately after unplugging the connector ground the two contacts of the male connector simultaneously on the side of the instrument to discharge the plasma tube 5 34 Servicing Replacing Instrument Assemblies Top View s P Z High Voltage Connector lS 7 Place the instrument on its left side so that the A1 assembly will not accidentally fall out of the instrument when the securing screws are removed highvott 8 Disconnect cables W4 and W10 shown in the following figure from their connectors on the A5 Main Board Assembly Free the cables from the cable clips 5 35 Servicing Replacing Instrument Assemblies AS w10 W4 optblk 9 While holding the Al assembly with one hand use a T 15 TORX driver to remove the four screws that attach the Al assembly to the instrument When reinstalling the Al assembly torque these four screws to 20 in Ibs 10 Gently remove the Al assembly while feeding cables W4 and W10 through the hole in the sheet metal 11 To install the Al assembly perform the steps in this procedure in reverse order WARNING WARNING Servicing
55. to the fre quency of the reference laser line The frequency of the reference laser line is returned as an absolute frequency Cunnormalized Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments 4 43 Syntax Attribute Summary Description Syntax Attribute Summary Programming Commands CALCulate3 Subsystem DRIFt DIFFerence STATe Sets the drift calculation to subtract the minimum values measured from the maximum values measured CALCulate3 DRIFt DIFFerence STATe ON OFF 1 O Preset State off RST State off SCPI Compliance instrument specific Use the CALC3 DRIF PRES command to turn off all the drift states before turning on this state The CALC3 DATA query returns the maximum power and frequency minus the minimum power and frequency Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments DRIFt MAXimum STATe Sets the drift calculation to return the maximum power and frequency values measured CALCulate3 DRIFt MAXimum STATe ON
56. 0 240V operation The use of other fuses or materials is prohibited 5 19 Servicing Testing Performance Testing Performance The procedures in this section test the HP 86120A s performance using the specifications listed in Chapter 6 Specifications and Regulatory Information as the performance standard All of the tests are done manually without the aid of a computer None of these tests require access to the interior of the instrument Test 1 Absolute Wavelength Accuracy Test 2 Sensitivity Test 3 Polarization Dependence Test 4 Optical Input Return Loss Test 5 Amplitude Accuracy and Linearity Allow the HP 86120A to warm up for 15 minutes before doing any of the per formance tests Calibration Cycle This instrument requires periodic verification of performance The instrument should have a complete verification of specifications at least once every year 5 20 Description CAUTION Procedure Servicing Testing Performance Test 1 Absolute Wavelength Accuracy Wavelength accuracy is verified using traceable light sources such as the fol lowing devices e Stable lasers e Gas lamps e HeNe gas lasers Do not exceed 18 dBm source power The HP 86120A s input circuitry can be damaged when total input power exceeds 18 dBm Use three or four light standards that cover the HP 86120A s wavelength range Connect the traceable sources to the HP 86120A and verify that the HP 86120A is readi
57. 0V for 100 240V operation The use of other fuses or materials is prohibited 1 6 WARNING CAUTION CAUTION CAUTION Getting Started Step 3 Connect the Line Power Cable Step 3 Connect the Line Power Cable 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 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 Do not connect ac power until you have verified the line voltage is correct as described in the following paragraphs Damage to the equipment could result This instrument has autoranging line voltage input Be sure the supply voltage is within the specified range 1 Verify that the line power meets the requirements shown in the following table Line Power Requirements Power 115 VAC 110 VA MAX 60 WATTS MAX 1 1 A MAX 230 VAC 150 VA MAX 70 WATTS MAX 0 6 A MAX Voltage nominal 115 VAC 230 VAC range 115 VAC 90 132 V range 230 VAC 198 254 V Frequency nominals 50 Hz 60 Hz range 47 63 Hz 2 Connect the line power cord to the instru
58. 1 Heatsink 5 0400 0387 4 Rubber grommet 6 86120 20009 4 Standoff 7 3050 1415 4 Flat Washer M4 0 8 0515 0456 4 Screw TORX T15 Pan Head M4 x 0 7 20 mm long g 1400 1582 3 Cable clip 11 mm x 16 mm 0 1400 1594 3 Cable clip 0 99 in x 0 99 in 1 86120 00004 1 Main deck sheet metal assembly 2 0515 0372 6 Screw TORX T10 Pan Head M3 x 0 5 8 mm long 3 1400 2132 4 Cable clip 2 75 in x 0 5 in 4 1400 2136 1 Cable clip 0 75 in x 0 75 in 5 0515 0372 8 Screw TORX T10 Pan Head M3 x 0 5 8 mm long 5 56 Servicing Replaceable Parts 13 14 o O ig 15 Ses ie wR 12 o A Oo aaa i 11 a 1 10 a 7 2 9 e 5X 6X 7X8 4 3 rpbotton 5 57 Servicing Replaceable Parts Table 5 13 Side View Parts Item eo Oty Description 1 0515 1102 4 Screw TORX T10 Flat Head M3 x 0 5 8 mm long 2 0515 2086 8 Screw TORX T15 Flat Head M4 x 0 7 7 mm long 3 0515 0430 8 Screw with washer TORX T10 Pan Head M3 x 0 5 6 mm long 4 5041 8928 4 Front frame bumper 5 58 Servicing Replaceable Parts 4 places 4 places per side rpside 5 59 Servicing Replaceable Parts Table 5 14 I
59. 14 laser drift 2 21 laser line separation 2 18 low power laser lines effects of 2 16 Index 4 modulated lasers effects of 2 32 monitoring performance over time 2 21 multiple laser lines 2 5 2 10 PRBS format present 2 27 2 32 relative power 2 18 relative wavelength 2 18 repetitive data formats 2 27 signal to noise 2 25 2 28 single acquisition 2 10 SONET format present 2 27 2 32 speed 2 10 3 10 4 28 4 64 total power 2 7 units 2 10 update rate 3 10 4 28 4 64 in vacuum 2 34 menu maps 7 5 messages error 7 12 microwatts 2 11 milliwatts 2 11 modulated lasers 2 32 monitoring the instrument 3 16 MW softkey 2 11 N nanometers 2 11 new line character 3 27 EXT PK softkey 2 8 EXT programming command 4 55 EXT WL softkey 2 8 NM softkey 2 11 noise declaration 6 10 noise power automatic interpolation 2 26 bandwidth 2 27 user entered wavelength 2 27 non sequential command 38 13 4 28 4 33 4 34 4 35 4 49 4 62 4 79 NORMAL softkey 2 10 2 12 3 10 4 64 notation definitions 4 2 NtTRansition programming command 4 68 NUM LINES lt NUM REFS 2 22 NUM LINES gt NUM REFS 2 22 numbers 3 26 O Off key 2 20 menu map 7 9 Index On key 2 20 menu map 7 8 OPC 3 31 4 4 4 7 OPTICAL INPUT connector 1 11 2 10 options 1 5 ordering parts 5 48 output queue 3 22 3 28 P packaging for shipment 1 16 PARALLEL PRINTER PORT connector 1 9 2 37 p
60. 1541 747 nm laser line is selected as the reference It is shown in absolute units The wavelengths and powers of the remaining responses are shown relative to this reference For example the first response is 2 596 nm below the reference 2 596nm 4 41dE ae 1 300 aa me SEESE 1541 747 5 46dEm mem OF Boece 1 95dB Pppp Wa EGG oe DEAE mem B H To determine channel spacing simply read the relative wavelength measure ment of the laser lines immediately preceding and following the reference Use the i and SELECT softkeys to change the reference laser line and read the channel spacing between each channel You can use relative power measurements to measure flatness pre emphasis ina WDM system Simply select one carrier as the reference and measure the remaining carriers relative to the reference level The power differences rep resent the system flatness Press RESET to turn off the delta calculations so that all responses are shown in absolute wavelength and powers Making Measurements Measuring Laser Separation To measure channel separation Press the front panel Preset key Press List by WL Press the Delta On key Use the Off key to turn off the measurement Select the type of separation to observe e A WL displays channel separation e AWL A PWR displays both channel separation and differences in power Use the and softkeys to select the reference laser line
61. 25 CALCulate2 subsystem 4 30 CALCulate3 subsystem 3 36 3 39 3 42 4 36 calibration accuracy 6 4 cycle 5 20 6 2 elevation 1 12 measurements 2 34 medium for light 1 13 care of cabinet 1 2 of fiber optics v case sensitivity 3 25 CE mark iii channel spacing 2 19 characteristics 6 6 classification laser 6 10 cleaning adapters 2 41 cabinet 1 2 fiber optic connections 2 38 2 40 non lensed connectors 2 40 CLEAR softkey 2 22 CLENgth programming command 4 24 CLS 3 21 4 4 CM 1 softkey 2 11 Cmd_opc subroutine 3 31 COH LEN softkey 2 31 coherence length iv 2 29 6 8 colon 3 25 commands combining 3 25 Index 1 Index common 3 23 measurement instructions 3 23 non sequential 3 13 4 28 4 33 4 34 4 35 4 49 4 62 4 79 standard SCPI 3 23 termination 3 27 common commands CLS clear status 4 4 ESE event status enable 3 30 4 4 ESR event status register 4 6 IDN identification number 3 31 4 7 OPC operation complete 3 31 4 7 RST reset 3 31 4 8 SRE service request enable 4 10 STB status byte 4 11 TRG trigger 4 12 TST test 4 12 WAI wait 4 13 definition 3 23 sending 3 26 computer control 3 6 CONFigure measurement instruction 4 14 connector care 2 38 Cont key 2 11 2 22 CONT softkey 2 37 CONTinuous programming command 4 78 CSA mark iii cursor 2 5 D damaged shipment 1 4 data corrupt or stale 3 27 4 8 7 16 data questionab
62. 3 80 Black Canada Japan 100V or a 8120 1378 Straight NEMA5 15P 203 80 Jade Gray 200V Brazil 8120 4753 Straight 230 90 Jade Gray Colombia Mexico 8120 1521 203 80 Jade Gray Philippines 8120 4754 90 230 90 Jade Gray Saudia Arabia Taiwan 8120 5182 Straight NEMA5 15P 200 78 Jade Gray 8120 5181 200 78 Jade Gray Jade Gray Jade Gray Part number for plug is industry identifier for plug only Number shown for cable is HP Part Number for complete cable including plug E Earth Ground L Line N Neutral 7 19 Reference Hewlett Packard Sales and Service Offices Hewlett Packard Sales and Service Offices Hewlett Packard Sales and Service Offices 1 of 2 U S FIELD OPERATIONS Headquarters California Northern California Southern Hewlett Packard Company Hewlett Packard Company Hewlett Packard Company 19320 Pruneridge Avenue 301 East Evelyn 1421 South Manhatten Ave Cupertino CA 95014 U S A Mountain View CA 94041 Fullerton CA 92631 800 752 0900 415 694 2000 714 999 6700 Colorado Georgia Illinois Hewlett Packard Company Hewlett Packard Company Hewlett Packard Company 24 Inverness Place East 2000 South Park Place 5201 Tollview Drive Englewood CO 80112 303 649 5000 Atlanta GA 30339 404 955 1500 Rolling Meadows IL 60008 708 342 2000 New Jersey Hewlett Packard Company 120 West Centu
63. 3 softkey 2 33 A PWR softkey 2 20 Q queries 3 28 multiple 3 28 queues 3 22 R radiation exposure 1 11 range wavelength 3 5 4 35 Index 5 Index range wavelengths 2 9 READ measurement instruction 4 14 rear panel labels 6 12 parts 5 52 regulatory duration 6 2 Remote annotation 3 4 repetitive data formats 2 27 replaceable parts 5 43 replacement procedures 5 30 Al optical block assembly 5 32 A3 high voltage power supply assembly 5 37 cable clip 5 41 instrument cover 5 31 line filter assembly 5 42 RESet programming command 4 46 RESET softkey 2 19 2 21 2 24 return loss 6 4 6 8 returning data 3 28 for service 1 15 RF modulation 2 32 RIGHT programming command 4 56 RST 3 4 3 31 4 8 S S N AUTO annotation 2 25 S N softkey 2 28 S N USER annotation 2 25 safety 1 11 symbols iii sales and service offices 7 20 SCALar programming command 4 14 SCPI standard commands for programmable instruments standard 3 23 syntax rules 3 2 3 23 second harmonic distortion 2 16 SELECT softkey 2 5 2 19 selectivity 6 4 6 8 semicolon 3 24 sending common commands 3 26 SENSe subsystem 4 61 sensitivity 6 4 6 7 serial number A1lA1 Interferometer 5 7 instrument 1 4 service 1 15 Index 6 request enable register 3 21 4 10 returning for 1 15 sales and service offices 7 20 Set_ese subroutine 3 30 settings conflict error 4 35 4 36 4 39 4 42 4 43 4 45 4 47 4 48 4
64. 34 14 65 2 36 Making Measurements Printing Measurement Results To create a hardcopy 1 Connect the printer to the HP 86120A s rear panel PARALLEL PRINTER PORT connector 2 Press Print You can use the ABORT and CONT softkey to stop and restart a print job that is in progress CAUTION Making Measurements Cleaning Connections for Accurate Measurements Cleaning Connections for Accurate Measurements Accurate and repeatable measurements require clean connections Use the following guidelines to achieve the best possible performance when making measurements on a fiber optic system e Keep connectors covered when not in use e Use dry connections whenever possible e Use the cleaning methods described in this section e Use care in handling all fiber optic connectors e When inserting a fiber optic connector into a front panel adapter make sure that the fiber end does not touch the outside of the mating connector or adapter Because of the small size of cores used in optical fibers care must be used to ensure good connections Poor connections result from core misalignment air gaps damaged fiber ends contamination and improper use and removal of index matching compounds Use dry connections Dry connectors are easier to clean and to keep clean Dry connections can be used with physically contacting connectors for exam ple Diamond HMS 10 HP FC PC DIN and ST If a dry connection has 40 dB return
65. 7 FUNCTION NOT YET IMPLEMENTED 38 PRINTER OFF LINE 39 PRINTER OUT OF PAPER 40 PRINTER ERROR DETECTED 7 13 Reference Error Messages Table 7 2 Instrument Specific Error Messages 3 of 3 Error Number Error Message 41 PRINTER TIMED OUT 42 PRINTOUT WAS ABORTED 43 OT ALLOWED IN COH LEN 44 NOT ALLOWED IN S N 45 UNKNOWN KEYPRESS 46 UM LINES lt NUM REFS 47 NUM LINES gt NUM REFS 48 O REFERENCE SIGNAL 49 UNKNOWN ERROR Table 7 3 General SCPI Error Messages 1 of 3 Reference Error Messages Error Number Desription 0 No errors 100 Command error unknown command 101 Invalid character 102 Syntax error 103 Invalid separator 104 Data type error 105 GET not allowed 108 Parameter not allowed 109 Missing parameter 112 Program mnemonic too long 113 Undefined header 120 Numeric data error 121 Invalid character in number 123 Exponent too large 124 Too many digits 128 Numeric data not allowed 131 Invalid suffix 134 Suffix too long 138 Suffix not allowed 141 Invalid character data 148 Character data not allowed 150 String data error 151 Invalid string data 7 15 Reference Error Messages Table
66. 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 TEC 801 4 1988 EN 50082 1 1992 0 5 kV Sig Lines 1 kV Power Lines TEC 1000 3 2 1995 EN 61000 3 2 1995 TEC 1000 3 3 1994 EN 61000 3 3 1994 Supplementary Information These products herewith complies with the requirements of the Low Voltage Directive 73 23 EEC and the EMC Directive 89 336 EEC Santa Rosa California USA 1 22 96 GEO Dixon Browder Quality Manager European Contact Your local Hewlett Packard Sales and Service Office or Hewlett Packard GmbH Department ZQ Standards Europe Herrenberger Strasse 130 D 71034 B blingen Germany FAX 49 7031 14 3143 6 11 Specifications and Regulatory Information Regulatory Information ay HEWLETT 86120A 700 1650 nm PACKARD MULTI WAVELENGTH METER frntview Front view of instrument rmn PRINTER CE uss rearview Rear new of instrument 6 12 Reference Contents Reference Reference Reference Instrument Preset Conditions 7 3 Menu Maps 7 5 Error Messages 7 12 Front Panel Fiber Optic Adapters 7 18 AC Line Power Cords 7 19 Hewlett Packard Sales and Service Offices 7 20 7 2 Reference Instrument Preset Conditions Instrument Preset Conditions Table 7 1 Instrument Conditions 1 of 2 ftom Settings after Settings af
67. Check if wavelength changed from last pass Repeat until delta wavelength lt 0 0015 nm or wavelength is stable Programming Example Programs COM Current_wl Diff_wl Target_wl Previous_diff Diff_diff Current_wl 0 Diff_wl 0 Target_wl 0 Previous_dif Diff_diff 0 ASSIGN Tls TO 724 ASSIGN Mwm TO 720 Initialize instrument DIM Identity 50 Identity OUTPUT Tls CLS OUTPUT Tls IDN ENTER TLS identity PRINT TLS IS A identity OUTPUT Mwm RST OUTPUT Mwm CLS OUTPUT Mwm IDN ENTER Mwm Identity PRINT MWM IS A identity Ask user for desired wavelength INPUT What wavelength nm do you wish to have Target_wl Target_wl Target_wl 1 0E 9 PRINT the target wavelength is Target_wl Set wavelength of tunable laser source OUTPUT Tls WAVE VALS Target_wl OUTPUT Tilszs OUTP ON Enter realignment loop REPEA OUTPUT Mwm MEAS SCAL POW WAV ENTER Mwm Current_wl PRINT The current wavelength is VALS Current_wl Diff_wl PROUND ABS Target_wl Current_wl 16 PRINT Diff between target amp Current is or VALS Diff_wl OUTPUT T1ls WAVEACT VALS Current_wl Diff_diff PROUND ABS Diff_wl Previous_diff 16 PRINT differential difference between two turn VALS Diff_diff Previous_diff Diff_wl UNTIL Diff_wl lt 1 5 1 0E
68. DELTa REFerence WAVelength Selects the signal to be used as the reference for the DELTa calculations CALCulate3 DELTa REFerence WNUMber Selects the signal to be used as the reference for the DELTa calculations CALCulate3 DELTa WAVelength STATe Turns the delta wavelength measurement mode on and off CALCulate3 DELTa WPOWer STATe Turns the delta wavelength and power measurement mode on and off CALCulate3 DRIFt D IFFerence STATe Sets the drift calculation to subtract the minimum values measured from the maximum values measured 3 47 Programming Lists of Commands Table 3 7 Programming Commands 3 of 5 Command Description Code Codes S indicates a standard SCPI command indicates an instrument specific command CALCulate3 DRIFt MAXimum STATe Sets the drift calculation to return the maximum power frequency values measured CALCulate3 DRIFt MINimum STATe Sets the drift calculation to return the minimum power frequency values measured CALCulate3 DRIFt PRESet Turns off all the drift states for DIFFerence MAXimum MINimum and REFerence CALCulate3 DRIFt REFerence RESet Places the current list of signals into the reference list CALCulate3 DRIFt REFerence STATe Turns the drift state on and off so that CALC3 DATA will return the reference signal list CALCulate3 DRIF
69. ECT key and the display changes to peak wavelength mode with the signal at the cursor displayed Annotation in the upper right corner of the display indicates whether the sig nals are ordered according to wavelength BY WL or power BY PWR The cursor shows the currently selected laser line As you scroll through the responses the current position of the selection cursor is shown along the screen s right side Laser Line Selection Cursor Power Bars Position of 1546 495nm 16 76dBm me Selection 1548 084 9 46 POZA deu ra AUS 1543 695 7 81 a OF amp 1551 3514 4 6 992 ear aE RT ge i 1552 933 10 30 mem m Medium for sothoys L E C aes listwl Display after List by WL key pressed 2 5 Making Measurements Measuring Wavelength and Power Also notice that power bars graphically show the relative power levels between laser lines Total power and average wavelength can be measured In the third available display mode the HP 86120A displays the average wave length as shown in the following figure The displayed power level is the total input power to the instrument It is the sum of the powers of each laser line it is not a measure of the average power level of the laser lines AYER AGE 1549 636nm 1 51 4em times The following equation shows how individual wavelengths of laser lines are summed together to obtain the average wavelength value where n
70. EFault The current marker position lt resolution gt Constants Examples Query Response MAXimum MINimum DEFault CONF ETC EAD EAS zw ONF ETG ARR ARR ARR ARR SCA EAD zw O EAS SCAL SCAL SCAL Programming Commands Measurement Instructions 0 01 resolution fast update 0 001 resolution normal Current resolution POW WAV DEF MAX POW WAV DEF MIN POW WAV POW WAV POW WAV 1300NM MAX POW WAV 1300NM MIN POW WAV 1300NM POW WAV 1300NM The following line is an example of a returned string when MEAS SCAL POW WAV MAX is sent 1 5529258E 006 If six laser lines are located and MEAS ARR POW WAV is sent the following string could be returned Notice that the first returned number indicates the number of laser line values returned in the query 6 1 54488100E 006 1 54648400E 006 1 54809000E 006 1 54969900E 006 1 55131100E 006 1 55292600E 006 4 21 Syntax Description lt expected value gt Constants Programming Commands Measurement Instructions MEASure ARRay SCALar POWer WNUMber Returns a wave number value POWer WNUMber lt expected_value gt lt resolution gt Used With lt expected_value gt lt resolution gt SCALar optional optional ARRay ignored optional a Although ignored this argument must be present if the resolution argument i
71. I Compliance instrument specific Command Only Description If the display is in the List by WL mode it will be changed to List by Ampl before the marker is moved 4 55 Syntax Attribute Summary Description Syntax Attribute Summary Description Programming Commands DISPlay Subsystem MARKer MAXimum RIGHt Moves the marker right to the next laser line DISPlay MARKer MAXimum RIGHt Preset State marker set to maximum power laser line RST State marker set to maximum power laser line SCPI Compliance instrument specific Command Only Moves the marker from the current marker position to the next laser line hav ing the following characteristic e longer wavelength e higher frequency e higher wave number If the display is in the List by Ampl mode it will be changed to List by WL before the marker is moved WINDow GRAPhics STATe Turns on and off the display of the power bars DISPlay WINDow GRAPhics STATe ON OFF 1 0 Preset State on RST State on SCPI Compliance standard Specifying on displays the power bars in all modes except the drift and signal to noise modes Specifying off prevents the display of power bars for all instru ment modes Programming Commands FETCh Measurement Instruction FETCh Measurement Instruction For information on the FETCh measurement instruction refer to Measure ment Instructions on page 4 14 4 57 Programming Commands HCOP
72. In this section you ll find all the error messages that the HP 86120A can dis play on its screen Table 7 2 on page 7 12 lists all instrument specific errors Table 7 3 on page 7 15 lists general SCPI errors Table 7 2 Instrument Specific Error Messages 1 of 3 Error Number Error Message 1 BAD CHECKSUM FROM MOTOR 2 MOTOR COMMUNICATION PROBLEM 3 MOTOR NOT MOVING 4 MOTOR INDEX PULSE NOT FOUND 5 MOTOR CHIP SET INIT FAILED 6 MOTOR COMMUTATION FAILURE 7 MOTOR NOT SETTLED 8 MOTOR DID NOT STOP 9 MOTOR MOTION ERROR 0 MOTOR POSITION LIMIT FAILED 1 MOTOR POSITION WRAP FAILED 12 POWER LEVEL TOO HIGH 13 DATA DOWNLOAD PROBLEM 14 DATA ACQUISITION PROBLEM 5 MAX NUMBER OF SIGNALS FOUND 16 MOTOR INTERRUPT RECEIVED Table 7 2 Instrument Specific Error Messages 2 of 3 Reference Error Messages Error Number Error Message 17 ROM BYTE UNERASED 18 ROM WRITE OPERATION FAILED 19 ROM DEFECTIVE 20 ROM DATA INVALID 21 ROM VERSION INCOMPATIBLE 22 ROM POLLING LIMITED OUT 23 INPUT OUT OF RANGE 24 BAD CAL ROM DATA 25 BAD CAL ROM DATA 26 BAD CAL ROM DATA 27 BAD CAL ROM DATA 28 BAD CAL ROM DATA 29 BAD CAL ROM DATA 30 NVSRAM WRITE OPERATION FAILED 31 SOFTWARE INITIALIZATION FAIL 32 HARDWARE INITIALIZATION FAIL 33 INITIALIZATION TIMEOUT 34 BATTERY FAILED 36 TOO MANY ERRORS 3
73. M Instrument Mwm DIM Err_msg 255 INTEGER Cme CLEAR 7 REPEAT OUTPUT Mwm ESR ENTER Mwm Cme OUTPUT Mwm SYST ERR ENTER Mwm Err_msg PRINT Err_msg UNTIL NOT BIT Cme 2 AND NOT BIT Cme 4 AND NOT BIT Cme 5 AND POS Err_msg 0 Subend SUBEND UHH Set_ese SUB Set_es COM Instrument Mwm OUTPUT Mwm ESE IVAL 00110100 2 SUBEND Identity DEF FNIdentity COM Instrument MwmV DIM Identity 50 IdentityS OUTPUT Mwm RST OUTPUT Mwm OPC F ER Mwm Opc_done OUTPUT Mwm IDN ER Mwm Identity URN Identity RE FNEND 3 33 Programming Example Programs Example 2 Measure a Fabry Perot laser This program measures the multiple laser lines of a Fabry Perot laser It mea sures both the power and wavelengths of each line First the program sets the HP 86120A in the single acquisition measurement mode Then it triggers the HP 86120A with the MEASure command to capture measurement data of the input spectrum Because the data is stored in the instrument s memory it can be queried as needed Refer to the introduction to this section for a description of each subroutine that is contained in this program COM Instrument Mwm ASSIGN Mwm TO 720 ON ERROR GOTO Error_msg Set_ese PRINT USING 37A 33A Multi Wavelength Meter Identity
74. NUM MEAS ARR POW WNUM CONF SCAL POW WNUM 6451 MAX FETC SCAL POW WNUM 6451 MIN READ SCAL POW WNUM 6451 MEAS SCAL POW WNUM 6451 Query Response If the MEAS SCAL POW WNUM 6451 command is sent and a 1550 nm laser line is present the following response would be returned to the computer 6 45286262E 005 Notice that the returned units are m7 If six laser lines are measured and MEAS ARR POW WNUM is sent the following response is returned Notice that the first returned number indicates the number of laser line values returned in the query 6 6 47298400E 005 6 46627900E 005 6 45957000E 005 6 452863 O0OE 005 6 44615600E 005 6 43945300E 005 MEASure SCALar LENGth COHerence ALPHa Queries the alpha constant Syntax H LENGth COHerence ALPHa Attribute Summary Query Only Description The alpha constant is a unitless ratio 4 23 Syntax Attribute Summary Description Syntax Attribute Summary Syntax Attribute Summary Description Programming Commands Measurement Instructions MEASure SCALar LENGth COHerence BETA Queries the beta constant LENGth COHerence BETA Query Only The beta constant is a unitless ratio MEASure SCALar LENGth COHerence CLENgth Queries the coherence length of the input signal in meters LENGth COHerence CLENgth Query Only MEASure SCALar LENGth COHerence DELay
75. OFF 1 0 Preset State off RST State off SCPI Compliance instrument specific Description Syntax Attribute Summary Description Programming Commands CALCulate3 Subsystem Use the CALC3 DRIF PRES command to turn off all the drift states before turning on this state The CALC3 DATA query returns the maximum power and frequency Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments DRIFt MINimum STATe Sets the drift calculation to return the minimum power and frequency values measured CALCulate3 DRIFt MINimum STATe ON OFF 1 0 Preset State off RST State off SCPI Compliance instrument specific Use the CALC3 DRIF PRES command to turn off all the drift states before turning on this state The CALC3 DATA query returns the minimum power or frequency Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments 4 45 Syntax Attribute Summary Description Syntax Attribute Summary Syntax Programming Commands CALCulate3 Subsyste
76. P O Box 87 Singapore 9115 65 271 9444 Taiwan Hewlett Packard Taiwan 8th Floor H P Building 337 Fu Hsing North Road Taipei Taiwan 886 2 712 0404 7 21 Reference Hewlett Packard Sales and Service Offices Index Numerics 1 nm annotation 2 27 A ABORt programming command 4 78 ABORT softkey 2 37 ac power cables 1 8 adding parameters 3 26 address See HP IB address adjustments 5 2 air measurements in 2 34 alpha factor 2 29 2 30 ALPHa programming command 4 23 AM modulation 2 13 2 32 amplitude offset 2 33 specifications 6 7 annotation asterisk 2 4 2 10 1 nm 2 27 AVERAGE 2 6 BY PWR 2 5 BY WL 2 5 DRIFT 2 21 M 2 5 PEAK 2 5 PWR OFS 2 33 Remote 3 4 S N AUTO 2 25 S N USER 2 25 STD AIR 2 34 VAC 2 34 Appl s key 2 23 2 28 2 31 menu map 7 6 ARRay programming command 4 14 assemblies instrument 5 8 5 46 asterisk 2 4 2 10 attenuation See external attenuation audio modulation effects of 2 13 2 32 AUTO programming command 4 48 softkey 2 28 AVERAGE annotation 2 6 average wavelength iv 2 6 Avg WL key 2 6 2 8 B BAR OFF softkey 2 9 BAR ON softkey 2 9 beta factor 2 29 2 31 BETA programming command 4 24 bit error rate 2 25 block diagram 3 6 BY PWR annotation 2 5 BY WL annotation 2 5 C cabinet cleaning 1 2 cables clip replacing 5 41 instrument 5 10 5 48 CAL softkey 1 12 CALCulatel subsystem 4
77. System for Optical Fiber Commu nications NIST Technical Note 1336 February 18 Take the average of the two fre quencies straddling gain center 2 Moore C E 1971 Atomic Energy Levels as Derived from the Analysis of Optical Spectra Vol 1 NSRDS NBS 35 Vol 1 COM 72 51282 December 77 3 D A Jennings F R Peterson and K M Evenson 1979 Frequency measure ment of the 260 THz 1 15 micron He Ne laser Optics Letters Vol 4 No 5 May 129 130 6 3 Amplitude Sensitivity Selectivity Input Power Maximum Number of Lines Input Input Return Loss Specifications and Regulatory Information Definition of Terms Calibration Accuracy indicates the maximum power calibration error at the specified wavelengths over the allowed environmental conditions The ampli tude calibration acccuracy is tracable to a National Institute of Standards and Technology NIST calibrated optical power meter NIST is the national stan dards laboratory of the United States Flatness refers to the maximum amplitude error in a measurement between two lines that are separated in wavelength by no more than the specified amount Linearity indicates the maximum power error in measuring the change in power of one laser line Polarization Dependence indicates the maximum displayed power variation as the polarization of the input signal is varied Display Resolution indicates the minimum incremental change in displayed po
78. To remove the instrument cover 5 31 To replace the Al Optical Block Assembly 5 32 To replace the A3 High Voltage Power Supply Assembly 5 37 To replace a cable clip 5 41 To replace line filter assembly FL1 5 42 Replaceable Parts 5 43 5 3 Servicing General Information General Information Whenever you contact Hewlett Packard about your HP 86120A have the com plete serial number and option designation available This will ensure you obtain accurate service information e Refer to Table 5 1 on page 5 6 for a list of service tools e Refer to Table 5 2 on page 5 7 for a list of internal labels e Refer to Table 5 3 on page 5 8 for the location of each instrument assembly e Refer to Table 5 4 on page 5 10 for the location of each cable Clean the cabinet using a damp cloth only Protect againt ESD damage Electrostatic discharge ESD can damage or destroy electronic components All work on electronic assemblies should be performed at a static safe work station Refer to Electrostatic Discharge Information on page 5 12 for more information on preventing ESD 5 4 WARNING CAUTION Servicing General Information To avoid exposure to the laser path of a CLASS Illa LASER PRODUCT do not open the A1A1 A1A2 or A1A3 assemblies There are no serviceable components inside Laser paths outside of the A1A1 A1A2 or A1A3 assemblies do not require precautions to maintain safety
79. Tus OPERation NTRansition lt integer gt lt imteger gt an interger from 0 to 65535 Attribute Summary Description Example Syntax Attribute Summary Description Example Programming Commands STATus Subsystem Preset State none RST State none SCPI Compliance standard Changes in the state of a condition register bit causes the associated OPERa tion Status or QUEStionable Status register bit to be set This command allows you to select a negative bit transition to trigger an event to be recognized A negative transition is defined to occur whenever the selected bit changes states from a 1 to a 0 You can enter any value from 0 to 65535 When queried the largest value that can be returned is 32767 This is because the most significant register bit cannot be set true OUTPUT 720 STATUS OPER NTRansition 16 OPERation QUEStionable PTRansition Selects bits in the event register which can be set by positive transitions of the corresponding bits in the condition register STATus OPERation PTRansition lt integer gt lt imteger gt an interger from 0 to 65535 Preset State none RST State none SCPI Compliance standard Changes in the state of a condition register bit causes the associated OPERa tion Status or QUEStionable Status event register bit to be set This command allows you to select a positive bit transition to trigger an event to be recog nized A positive tran
80. WATTS MAX 0 6 A MAX nominal 115 VAC 230 VAC range 115 VAC 90 132 V range 230 VAC 198 254 V nominals 50 Hz 60 Hz range 47 63 Hz Up to 15 000 feet 4 572 meters 0 C to 55 C 80 for temperatures up to 31 C decreasing linearly to 50 relative humidity at 40 C 8 5 kg 19 Ib 140 x 340 x 465 mm 5 5 x 13 4 x 18 3 in 6 9 Specifications and Regulatory Information Regulatory Information Regulatory Information e Laser Classification This product contains an FDA Laser Class I IEC Laser Class 1 laser e This product complies with 21 CFR 1040 10 and 1040 11 Notice for Germany Noise Declaration Acoustic Noise Emission Geraeuschemission LpA lt 70 dB LpA lt 70 dB Operator position am Arbeitsplatz Normal position normaler Betrieb per ISO 7779 nach DIN 45635 t 19 Specifications and Regulatory Information Regulatory Information DECLARATION OF CONFORMITY according to ISO IEC Guide 22 and EN 45014 Manufacturer s Name Hewlett Packard Co Manufacturer s Address 1400 Fountaingrove Parkway Santa Rosa CA 95403 1799 USA declares that the product Product Name Multi Wavelength Meter Model Number HP 86120A Product Options This declaration covers all options of the above product conforms to the following Product specifications Safety IEC 1010 1 1990 A1 EN 61010 1 1993 CAN CSA C22 2 No 1010 1 92 EMC CISPR 11 1990 EN 55011 1991 Group 1 Class A TEC
81. _ref_pwr 1 Nb_pt 3 36 Programming Example Programs Query reference wavelengths and powers OUTPUT Mwm CALC3 DATA WAV ENTER Mwm USING K Current_ref_wl OUTPUT Mwm CALC3 DATA POW ENTER Mwm USING K Current_ref_pwr Turn off drift reference stat Cmd_opce CALC3 DRIF REF STAT OFF Err_mngmt CALC3 DRIF REF STAT OFF Turn on drift max min calculation Cmd_ope CALC3 DRIF DIFF STAT ON Err_mngmt CALC3 DRIF DIFF STAT ON Tempo 10 ALLOCATE Current_diff_wl 1 Nb_pt ALLOCATE Current_diff_pw 1 Nb_pt Query drift wavelengths and powers OUTPUT Mwm CALC3 DATA WAV ENTER wm USING K Current_diff_wl OUTPUT Mwm CALC3 DATA POW ENTER wm USING K Current_diff_pw OFF TIMEOUT FOR I 1 TO Nb_pt PRINT USING 18A 2D 6A M4D 2DE 3A 21A MDD 3DE 3A Wavelength number Ip is s Current_ref_wl I m with a drift from Current_diff_wl I m PRINT USING 28A SDD 2DE 4A 20A MDD 3DE 3A it has a power level of Current_ref_pwr I dBm with a drift from Current_diff_pw I dB EXT I STOP gt gt aa Error_msg PRINT The program is aborted due to ERRMS END 3 37 Programming Examp CO DI Err_mngmt SUB le Programs
82. a vacuum SCPI Compliance instrument specific After entering this value use the SNR AUTO command to configure the instrument to use this value in subsequent signal to noise calculations The wave number entered is converted internally to the corresponding frequency The default units for the lt real gt parameter is mt SNR STATe Turns the signal to noise calculation on and off CALCulate3 SNR STATe ON OFF 1 0 Preset State off RST State off SCPI Compliance instrument specific Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments Programming Commands CONFigure Measurement Instruction CONFigure Measurement Instruction For information on the CONFigure measurement instruction refer to Mea surement Instructions on page 4 14 Programming Commands DISPlay Subsystem DISPlay Subsystem The commands in this subsystem have the following command hierarchy DISPlay MARKer MAXimum LEFT NEXT PREVious RIGHt WINDow GRAPhics STATe 4 53 Programming Commands DISPlay Subsystem MARKer MAXimum Sets the marker to the laser line that has the maximum power Syntax DISPlay MARKer MAXimum Attribute Summary Preset State marker set to m
83. aces the display in the List by Power or List by WL modes an array of data is returned to the com puter A common programming error is to send the MEASure command when the instrument is in the continuous measurement acquisition mode Because MEASure contains an INIT IMM command which expects the single mea surement acquisition mode an error is generated and the INIT command is ignored READ command The READ command works like the MEASure command except that it does not configure the instrument s settings You can use the CONFigure command to configure the instrument for a particular measurement without returning any data The MEASure and READ commands are identical to combining the following commands Command Equivalent Commands MEASure ABORt CONFigure READ READ ABORt INITiate MMediate FETCh A common programming error is to send the READ command when the instrument is in the continuous measurement acquisition mode Because READ contains an INIT IMM command which expects the single measure ment acquisition mode an error is generated and the INIT command is ignored FETCh command The FETCh command returns data from previously performed measurements it does not initiate the collection of new data Because FETCh does not config ure the instrument or acquire new input data you can use FETCh repeatedly on the same set of acquired data For example use two FETCh commands to return wavelength and then pow
84. acing of the envelope peaks is measured This is equal to the diode laser cavity round trip optical length 2nLd Alpha factor The alpha factor is defined as the height of the first envelope peak away from zero path delay relative to the height of the envelope peak at zero path delay The alpha factor is always between 0 and 1 2 30 Making Measurements Measuring Coherence Length The smaller the alpha factor the shorter the coherence length Va Alpha factor v oO Beta factor The beta factor is defined as the height of the fringe visibility envelope mid way between the zero optical path delay peak and the next peak relative to the height of the envelope peak at zero path delay The beta factor is always between 0 and 1 The smaller the beta factor the more longitudinal modes wavelengths the laser has Vg Beta factor V To measure coherence length 1 Press the front panel Preset key 2 Press Appl s and then COH LEN Making Measurements Measuring Modulated Lasers Measuring Modulated Lasers A laser that is amplitude modulated at low frequencies for example modu lated in the audio frequency range can cause spurious wavelengths to be dis played below and above the correct wavelength The power of these spurious wavelengths is below that of the correct wavelength These spurious signals can be eliminated by decreasing the peak threshold Refer to Defining Laser Line Peaks on page 2 13 E
85. acter The following is an example of the first few lines and last few lines returned in the string The term nquery indicates that a command cannot be sent as a query The tirm gonly indicates that a command can only be sent as a query 44010 ABORt nquery CALCulate DATA qonly CALCulate TRANsform FREQuency POINts CALCulatel DATA qonly gt CALCulatel TRANsform FREQuency POINts CALCulate2 DATA qonly IDN qonly OPC RST nquery SRE STB qonly TRG nquery TST qonly WAI nquery 4 73 Programming Commands SYSTem Subsystem PRESet Performs the equivalent of pressing the front panel PRESET key Syntax SYSTem PRESet Attribute Summary Preset State none RST State none SCPI Compliance standard Command Only Description The instrument state is set according to the settings shown in the following table Table 4 8 Instrument Conditions Programming Commands SYSTem Subsystem item Settings after Settings after Preset Key Pressed Power Turned On Display mode single wavelength last state Wavelength range limiting on ast state Measurement acquisition continuous ast state Wavelength calibration vacuum ast state Elevation correction value not affected ast state Wavelength units nm ast state Amplitude units dBm ast state Power offset 0 dB ast state Peak threshold 10 dB ast state Peak excursion
86. actor Coherence length in the region of 1 mm to 200 mm can be measured The fol lowing figure shows a coherence length measurement COHEREWCE LEHGTH x Le 9 6 mm EY WL ZnLo 1 491 mm 5 OF alpha H 984 YAT beta 0 061 a M C JC JC JE enr Coherence length L The interferogram of the laser being tested is sampled and the envelope of the interferogram is found This envelope has peaks regions of high fringe visibil ity at zero optical path delay and at delays equal to multiples of the laser cav ity round trip optical length This is shown in the following figure of the interferogram envelope Making Measurements Measuring Coherence Length Interferogram Envelope 0 nk L Mo Optical Path Delay CPD S envinter The amplitudes of the peaks decreases exponentially from the largest peak at zero path delay The exponential decay constant is defined as the coherence length Lc The curve that connects the tops of the envelope peaks is given by the following equation OPD L decay curve e OPD is the optical path delay and Lc is the coherence length Thus at an opti cal path delay equal to the coherence length the envelope peaks are down to 1 e of their value at zero path delay peak All envelope peaks found are used to determine the exponential decay constant coherence length using a least squares fit Round trip optical length of diode laser cavity 2nLd The average optical path delay sp
87. adian Standards Association iii The HP 86120A At a Glance The HP 86120A At a Glance The HP 86120A Multi Wavelength Meter measures the wavelength and optical power of laser light in the 700 1650 nm wavelength range Because the HP 86120A simultaneously measures multiple laser lines you can characterize wavelength division multiplexed WDM systems and the multiple lines of Fabry Perot lasers Characterize laser lines easily With the HP 86120A you can quickly and easily measure any of the following parameters Peak wavelength and power Average wavelength Total optical power Laser line separation Laser drift wavelength and power Signal to noise ratios unmodulated lasers Coherence length In addition to these measurements a power bar is displayed that shows power changes like a traditional analog meter You can see the power bar shown in the following figure of the HP 86120A s display 1551 314nm 5 92 dBm amp LINES PREY WL HEXT WL Peak HEXT PE peakwl iv CAUTION The HP 86120A At a Glance The HP 86120A s input circuitry can be damaged when total input power levels exceed 18 dBm To prevent input damage this specified level must not be exceeded Print measurement results You can get hardcopy results of your measurements by connecting a printer to the rear panel PARALLEL PRINTER PORT connector Program the instrument for automatic measurements The
88. alculatel Subsystem Calculate2 Subsystem Calculate3 Subsystem Display Subsystem Hcopy Subsystem Sense Subsystem Status Subsystem System Subsystem Trigger Subsystem Unit Subsystem Sending a command It s easy to send a command to the instrument Simply create a command string from the commands listed in this book and place the string in your pro gram language s output statement For commands other than common com mands include a colon before the subsystem name For example the following string places the cursor on the peak laser line and returns the power level of this peak OUTPUT 720 MEAS SCAL POW MAX Use either short or long forms Commands and queries may be sent in either long form complete spelling or short form abbreviated spelling The description of each command in this manual shows both versions the extra characters for the long form are shown in lowercase The following is a long form of a command OUTPUT 720 MEASure SCALar POWer MAXimum And this is the short form of the same command OUTPUT 720 MEAS SCAL POW MAX Programs written in long form are easily read and are almost self document ing Using short form commands conserves the amount of controller memory needed for program storage and reduces the amount of I O activity The rules for creating short forms from the long form is as follows 3 24 Programming Reviewing SCPI Syntax Rules The mnemonic is t
89. and error bit in the status byte register is set 4 5 Programming Commands Common Commands ESR The ESR event status register query returns the value of the event status register Syntax ESR Description When you read the standard event status register the value returned is the total of the bit weights of all of the bits that are set to one at the time you read the byte The following table shows each bit in the event status register and its bit weight The register is cleared when it is read Table 4 3 Standard Event Status Register Bit Bit Weight Condition 7 128 PON Power On 6 64 Not Used 5 32 CME Command Error 4 16 EXE Execution Error 3 8 DDE Device Dependent Error 2 4 QYE Query Error 1 2 Not Used 0 1 OPC Operation Complete Query Response lt imteger gt ranges from 0 to 255 4 6 Example Syntax Description Query Response Example Syntax Description Programming Commands Common Commands OUTPUT 720 ESR ENTER 720 Event PRINT Event IDN The IDN identification number query returns a string value which identi fies the instrument type and firmware version IDN An IDN query must be the last query in a program message Any queries after the IDN query in a program message are ignored The maximum length of the identification string is 50 bytes The following identifi
90. arameters adding 3 26 parts bottom of instrument 5 56 cables 5 10 5 48 cover assembly 5 60 front panel 5 50 major assemblies 5 8 5 46 ordering 5 43 rear panel 5 52 replacing 5 30 5 48 side of instrument 5 58 top of instrument 5 54 PEAK annotation 2 5 softkey 2 8 2 28 peak definition of 2 18 excursion 2 14 power iv 2 8 threshold limit 2 13 2 16 2 32 wavelength iv 2 8 Peak WL key 2 4 menu map 7 9 softkey 2 8 2 23 performance tests 5 20 PEXCursion programming command 4 32 PK EXC softkey 2 16 PK THLD softkey 2 16 POINts programming command 4 28 4 33 4 48 polarization dependence 6 4 6 7 power bar iv 2 5 2 9 maximum before damage 2 2 maximum input v maximum measurable 2 2 measuring total 2 6 4 31 4 34 peak 2 8 separation 2 18 state when turned on 4 75 7 3 tuning laser 2 5 POWer programming command 4 16 4 40 4 80 POWER softkey 2 11 PRBS 2 27 2 32 Preset conditions set by 4 75 7 3 key 2 2 3 5 menu map 7 9 PRESet programming command 4 39 4 46 4 70 4 74 PREV PK softkey 2 8 PREV WL softkey 2 8 PREVious programming command 4 55 Print key 2 36 menu map 7 10 printer cable 1 9 connecting 1 9 output 2 36 programming 3 2 command notation convention 4 2 equivalent softkeys 3 51 examples See example programs list of commands 3 46 measurement instructions 4 14 PTRansition programming command 4 69 PWR BAR softkey 2 9 PWR OFS annotation 2 3
91. ations and Regulatory Information Procedure Option 022 instruments angled contacting connectors l Servicing Testing Performance Turn the source module s output off 2 Connect a single mode patchcord between the source module s optical 10 11 12 13 output and the return loss module s INPUT SOURCE connector Set the return loss module s wavelength to 1550 nm and select an average time of 1 second Locate an HMS 10 HP HRL to FC APC angled FC patchcord Connect the HMS 10 HP HRL end of the patchcord to the return loss module s OUTPUT connector Terminate the FC APC end of the cable Zero the return loss module Turn on the source module Remove the termination from the cable and connect the FC APC end of an FC APC to FC PC cable to the free end of this cable Leave the cable s free end uncovered The return loss module measures the reflection reference 14 6 dB return loss of the patchcord s FC PC connector in air Disconnect the FC APC to FC PC cable Make a low reflection termination in the HMS 10 HP HRL to FC APC patchcord Do this by wrapping the cable 6 times around a 5 mm diameter mandrel The return loss module measures the termination parameter Connect the HMS 10 HP HRL to FC APC patchcord to the HP 86120A s front panel OPTICAL INPUT connector The lightwave multimeter measures the return loss Compare this measurement with the specification listed in Chapter 6
92. aximum power laser line RST State marker set to maximum power laser line SCPI Compliance instrument specific Command Only MARKer MAXimum LEFT Moves the marker left to the next laser line Syntax DISPlay MARKer MAXimum LEFT Attribute Summary Preset State marker set to maximum power laser line RST State marker set to maximum power laser line SCPI Compliance instrument specific Command Only Description Moves the marker from the current marker position to the next laser line hav ing the following characteristic e shorter wavelength e lower frequency e lower wave number If the display is in the List by Ampl mode it will be changed to List by WL before the marker is moved 4 54 Programming Commands DISPlay Subsystem MARKer MAXimum NEXT Moves the marker to the laser line with the next lower power level Syntax DISPlay MARKer MAXimum NEXT Attribute Summary Preset State marker set to maximum power laser line RST State marker set to maximum power laser line SCPI Compliance instrument specifid Command Only Description If the display is in the List by WL mode it will be changed to List by Ampl before the marker is moved MARKer MAXimum PREVious Moves the marker to the laser line that has the next higher power level Syntax DISPlay MARKer MAXimum PREVious Attribute Summary Preset State marker set to maximum power laser line RST State marker set to maximum power laser line SCP
93. cation string is returned The last entry in the string is the firmware version number this value may vary between instruments HEWLETT PACKARD 86120A 0 1 000 DIM Ids 50 OUTPUT 720 IDN ENTER 720 Id PRINT Id OPC The OPC operation complete command sets the operation complete bit in the event status register when all pending device operations have finished OPC OPC The OPC query places an ASCII 1 in the output queue when all pending device operations have finished 4 7 Query Response Example Syntax Description Programming Commands Common Commands This command is useful when the computer is sending commands to other instruments The computer can poll the event status register to check when the HP 86120A has completed the operation Use the OPC query to ensure all operations have completed before continuing the program By following a command with an OPC query and an ENTER statement the program will pause until the response ASCII 1 is returned by the instrument Be sure the computer s timeout limit is at least two seconds since some of the HP 86120A commands take approximately one second to complete OUTPUT 720 OPC ENTER 720 0p RST The RST reset command returns the HP 86120A to a known condition RST For a listing of reset conditions refer to the following table This command cannot be issued as a qu
94. ccounted for To measure total power exceeding 10 dBm The maximum total input power that can be applied to the HP 86120A before damage occurs is 18 dBm The maximum total input power that can be mea sured is 10 dBm 1 Connect an optical attenuator between the front panel OPTICAL INPUT connector and the fiber optic cable The attenuator must reduce the total input power to the HP 86120A so that it is below 10 dBm 2 Press Setup CAL and then PWR OFS Notice that the PWR OFS annotation appears on the screen to indicate an offset is applied 3 Usethe softkey to select the digit that requires editing 4 Usethe amp and softkeys to change the value Power offset values are added to the display power readings For example if you placed a 10 dB attenuator on the front panel connector enter a power off set value of 10 dB Negative values can also be entered if you connect an amplifier instead of an attenuator Making Measurements Calibrating Measurements Calibrating Measurements The wavelength of light changes depending on the material that the light is passing through To display meaningful wavelength measurements the HP 86120A performs two steps 1 Measures the wavelength in air 2 Converts the wavelength to show values in either a vacuum or standard air For example a laser line with a wavelength of 1550 000 nm in a vacuum would have a wavelength in standard air of 1549 577 nm Because al
95. ch prove to be defective For warranty service or repair this product must be returned to a service facility designated by Hewlett Packard Buyer shall prepay shipping charges to Hewlett Packard and Hewlett Packard shall pay shipping charges to return the product to Buyer However Buyer shall pay all shipping charges duties and taxes for products returned to Hewlett Packard from another country Hewlett Packard warrants that its software and firmware designated by Hewlett Packard for use with an instrument will execute its programming instructions when properly installed on that instrument Hewlett Packard does not warrant that the operation of the instrument or software or firm ware will be uninterrupted or error free The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HEWLETT PACKARD SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR A PARTICULAR PURPOSE THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES HEWLETT PACKARD SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAM AGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY Contents Th
96. ction ELEVation EXIT none FAST See UPDATE HP IB none LIM OFF CALCulate2 WLIMit STATe OFF LIM ON CALCulate2 WLIMit STATe ON List by Power CONFigure ARRay POWer List by WL MEASure ARRay POWer WAVelength MAX MIN CALCulate3 DRIFt MINimum STATe and CALCulate3 DRIFt MAXimum STATe MW UNIT POWer 3 51 Programming Lists of Commands Table 3 8 Keys Versus Commands 2 of 3 Key Equivalent Command NEXT PK DISPlay MARKer MAXimum NEXT NEXT WL DISPlay MARKer MAXimum RIGHt NM gt MEASure ARRay POWer WAVelength NORMAL See UPDATE OFF CALCulate3 DELTa POWer STATe ON CALCulate3 DELTa POWer STATe PEAK DISPlay MARKer MAXimum Peak WL See NEXT PK NEXT WL PEAK PREV PK and PREV WL PK EXC CALCulate2 PEXCursion PK THLD CALCulate2 PTHReshold POWER UNIT POWer Preset SYSTem PRESe PREV PK DISPlay MARKer MAXimum PREVious PREV WL DISPlay MARKer MAXimum LEFT Print HCOPy IMMediate PWR BAR See BAR ON and BAR OFF PWR OFF SENSe CORRection OFFSet MAGNitude RESET CALCulate3 DRIFt REFerence RESet S N CALCulate3 SNR STATe SELECT CONFigure POWer Setup See CAL UNITS and UPDATE Single INITiate CONTinuous OFF STD AIR SENSe CORRection MEDium AIR THRSHLD See PK EXC and PK THLD 3 52 Programming Lists of Commands Table 3 8 Keys Versus Commands 3 of 3 K
97. curs All this is accomplished using the ESE common command 3 30 Programming Example Programs The Err_mngmt subroutine is used to actually read the value of the event sta tus register Examples 1 through 5 call this subroutine FNIidentity function When this function is called it resets the instrument and queries the instru ment s identification string which is displayed on the the computer s screen by the calling function To accomplish this task the FNIdentity function uses the RST OPC and IDN common commands This function is called from examples 1 through 5 Err_mngmt subroutine This subroutine checks to make sure that no errors have set bits in the event status register and that there are no errors in the queue Exiting this subrou tine is only possible if no errors have occurred Notice that the logic test in the subroutine tests for the same event status register bits enabled by the Set_ese subroutine BIT Cme 5 BIT Cme 4 BIT Cme 2 This subroutine is called in examples 1 through 5 However it is modified in examples 3 4 and 5 to allow it to indicate the last programming command that was sent to the instrument before an error occurred This is accomplished by adding an optional argument string Cmd_opc subroutine The Cmd_opc subroutine found in examples 3 4 and 5 pauses the program until a non sequential command has finished executing on the HP 86120A It uses the OPC query For more infor
98. d in the query The measurement units are in dBm 6 1 37444400E 001 1 10996100E 001 9 62396600E 000 7 94024500E 000 7 01303200E 000 1 04536200E 001 4 17 Syntax Description lt expected_value gt Constants Programming Commands Measurement Instructions MEASure ARRay SCALar POWer FREQuency Returns frequency values POWer FREQuency lt expected_value gt lt resolution gt Used With lt expected_value gt lt resolution gt SCALar optional optional ARRay ignored optional a Although ignored this argument must be present if the resolution argument is specified When used with a SCALar command a single value is returned The display is placed in the single wavelength mode and the marker is placed on the signal having a frequency that is closest to the lt expected_value gt parameter Default units for lt expected_value gt parameter is in Hz When used with an ARRay command an array of frequencies is returned The display is placed in the list by wavelength mode The lt resolution gt parameter sets the resolution of the measurement It is a unitless number whose value will be limited to either 0 01 or 0 001 whichever is closer MAXimum resolution is equivalent to the FAST measurement update mode MINimum resolution is equivalent to the NORMAL measurement update mode Returned values are in Hz display is in THz Power units are not affect
99. e 3 13 for more information 4 79 Programming Commands UNIT Subsystem UNIT Subsystem The only command provided in this subsystem is the POWer command as shown in the following command hierarchy UNIT POWer POWer Sets the power units to watts linear or dBm logarithmic Syntax UNIT POWer W DBM Attribute Summary Preset State dBm RST State dBm SCPI Compliance standard Servicing WARNING WARNING WARNING WARNING Servicing Servicing Servicing In this chapter you ll find information on troubleshooting performance test ing and replacing parts in the instrument There are no adjustments required for the HP 86120A Safety first Before servicing the HP 86120A familiarize yourself with the safety markings on the instrument and the safety instructions in this manual This instrument has been manufactured and tested according to international safety stan dards To ensure safe operation of the instrument and the personal safety of the user and service personnel the cautions and warnings in this manual must be heeded Refer to the summary of safety considerations at the front of this manual These servicing instructions are for use by qualified personnel only To avoid electrical shock do not perform any servicing unless you are qualified to do so The opening of covers or removal of parts is likely to expose dangerous voltages Disconnect the instrument f
100. e HP 86120A At a Glance iv Getting Started Step 1 Inspect the Shipment 1 4 Step 2 Check the Fuse 1 6 Step 3 Connect the Line Power Cable 1 7 Step 4 Connect a Printer 1 9 Step 5 Turn on the HP 86120A 1 10 Step 6 Enter Your Elevation 1 12 Step 7 Select Medium for Wavelength Values 1 13 Step 8 Turn Off Wavelength Limiting 1 14 Returning the Instrument for Service 1 15 Making Measurements Measuring Wavelength and Power 2 4 Changing the Units and Measurement Rate 2 10 Defining Laser Line Peaks 2 13 Measuring Laser Separation 2 18 Measuring Laser Drift 2 21 Measuring Signal to Noise Ratios 2 25 Measuring Coherence Length 2 29 Measuring Modulated Lasers 2 32 Measuring Total Power Greater than 10 dBm 2 33 Calibrating Measurements 2 34 Printing Measurement Results 2 36 Cleaning Connections for Accurate Measurements 2 38 Programming Addressing and Initializing the Instrument 3 4 Making Measurements 3 6 Monitoring the Instrument 3 16 Reviewing SCPI Syntax Rules 3 23 Example Programs 3 30 Lists of Commands 3 46 Contents 1 Contents p 4 Programming Commands Common Commands 4 4 Measurement Instructions 4 14 CALCulatel Subsystem 4 25 CALCulate2 Subsystem 4 30 CALCulate3 Subsystem 4 36 CONFigure Measurement Instruction 4 52 DISPlay Subsystem 4 53 FETCh Measurement Instruction 4 57 HCOPy Subsystem 4 58 MEASure Measurement Instruction 4 59 READ Measurement Instruction 4 60 SENSe Subsystem
101. e Standard Event Sta tus Register Because the bits are all enabled a summary bit is generated to set bit 5 in the Status Byte Register If bit 5 ESB in the Status Byte Register is enabled via the SRE command an SRQ service request interrupt is sent to the external computer Standard Event Status Register bits that are not enabled still respond to their corresponding conditions that is they are set if the corresponding event occurs However because they are not enabled they do not generate a sum mary bit to the Status Byte Register 3 21 Programming Monitoring the Instrument Queues There are two queues in the instrument the output queue and the error queue The values in the output queue and the error queue can be queried Output queue The output queue stores the instrument responses that are generated by cer tain commands and queries that you send to the instrument The output queue generates the Message Available summary bit when the output queue contains one or more bytes This summary bit sets the MAV bit bit 4 in the Status Byte Register The method used to read the Output Queue depends upon the programming language and environment For example with HP Basic the output queue may be read using the ENTER statement Error queue As errors are detected they are placed in an error queue Instrument specific errors are indicated by positive values General errors have negative values You can clear the error
102. e following example programs are provided in this section Example 1 Measure a DFB laser 3 32 Example 2 Measure a Fabry Perot laser 3 34 Example 3 Measure a Fabry Perot laser s drift 3 36 Example 4 Measure laser line separation 3 39 Example 5 Measure signal to noise ratio 3 42 Example 6 Increase a source s wavelength accuracy 3 44 These programs are provided to give you examples of using HP 86120A remote programming commands in typical applications They are not meant to teach general programming techniques or provide ready to use solutions They should allow you to see how measurements are performed and how to return data to the computer All of the examples are written in the HP BASIC programming language Many subroutines are repeated in the examples The first five example programs contain several common subroutines These routines along with one function are described in the rest of this introduc tion The descriptions are listed in the general order that the subroutines are called in the programs Error_msg subroutine This function is found in examples 2 3 4 and 5 It displays an error message on the computer s screen explaining the reason that the program s execution stopped Set_ese subroutine The subroutine sets the enable mask for the event status register to a value of 52 This allows bits 2 4 and 5 to be set whenever a query error QYE execu tion error EXE or command error CME respectively oc
103. e in the service request enable register enables the corresponding bit in the status byte register to generate a service request A zero disables the bit The following table lists the bits in the service request enable register and what they mask The service request enable register is cleared when the instrument is turned on The RST and CLS commands do not change the register The SRE query returns the value of the service request enable register Table 4 5 Service Request Enable Register Bit Bit Weight Enables 7 128 Not Used 6 64 Not Used 5 32 Event Status Bit ESB 4 16 Message Available MAV 3 8 Not Used 2 4 Error queue status 1 2 Not Used 0 1 Not Used a High enables the status byte register bit Query Response lt integer gt from 0 to 63 for 128 to 191 4 10 Example Syntax Description Query Response Programming Commands Common Commands OUTPUT 720 SRE 32 In this example the command enables ESB event summary bit 5 in the sta tus byte register to generate a service request STB The STB status byte query returns the current value of the instrument s status byte STB The master summary status MSS bit 6 indicates whether or not the device has at least one reason for requesting service When you read the status byte register the value returned is the total of the bit weights of all of the bits set to one at the time you read
104. e that only values are returned to the computer There is no first value that indicates the number of values contained in the string as there is for example with the FETCh READ and MEASure commands 4 65 Programming Commands STATus Subsystem STATus Subsystem Use the commands in this subsystem to control the HP 86120A s status reporting structures These structures provide registers that you can use to determine if certain events have occurred The commands in this subsystem have the following command hierarchy STATus OPERation CONDition ENABle EVENt PTRansition NTRansition PRESet QUEStionable CONDition ENABle EVENt PTRansition NTRansition Syntax Query Response Attribute Summary Description Example Syntax Attribute Summary Description Programming Commands STATus Subsystem OPERation QUEStionable CONDition Queries the value of the questionable or operation condition register STATus OPERation QUEStionable CONDition 0 to 32767 Preset State none RST State none SCPI Compliance standard Query Only Use this command to read the value of the OPERation Status or QUEStionable Status registers Refer to Monitoring the Instrument on page 3 16 OUTPUT 720 STATUS OPERATION CONDITION OPERation QUEStionable ENABle Sets the enable mask for the questionable or operation event register STATus OPERation
105. e the wavelength closest to the reference wavelength used for the previous measurement The query returns the current wavelength of the reference laser line The default units for the lt real gt parameter is in meters DELTa REFerence WNUMber Selects the reference laser line for delta calculations CALCulate3 DELTa REFerence WNUMber lt real gt MINimum MAXimum lt real gt is a wave number value that is within the following limits Constant Description MINimum 6 061 MAXimum 14 286 4 41 Attribute Summary Description Syntax Attribute Summary Description Programming Commands CALCulate3 Subsystem Preset State 14 286 cm 700 nm RST State 14 286 cm 700 nm SCPI Compliance instrument specific The reference will be the laser line at the wave number closest to the wave number entered Subsequent measurements will use the wave number closest to the reference wave number used for the previous measurement The query returns the current wave number of the reference laser line The default units for the lt real gt parameter is in m DELTa WAVelength STATe Turns the delta wavelength measurement mode on and off CALCulate3 DELTa WAVelength STATe ON OFF 1 0 Preset State off RST State off SCPI Compliance instrument specific When on the wavelength of the reference laser line is subtracted from the wavelength values of all laser lines except the r
106. ection OFFSet MAGNitude Enters an offset for amplitude values SENSe CORRection OFFSet MAGNitude lt real gt MINimum MAXimum lt real gt is the logarithmic units in dB Constant Description MINimum 40 0 dB MAXimum 40 0 dB 4 63 Attribute Summary Querry Response Syntax Attribute Summary Description Programming Commands SENSe Subsystem Preset State 0 0 RST State 0 0 SCPI Compliance standard The query form returns the current offset setting as shown in the following example 5 00000000E 000 DATA Queries the time domain samples of the input laser line SENSe DATA Preset State none SCPI Compliance instrument specific Query Only Be prepared to process a large amount of data when this query is sent The amount of data returned depends on the measurement update state of the instrument which is set using the resolution argument of an instrument func tion Refer to Measurement Instructions on page 4 14 When NORMAL measurement update is specified over 2 200 kilobytes of data 128K values can be returned to the computer When FAST measurement update is specified over 250 kilobytes of data 16K values can be returned The floating point values are scaled from 1 000 to 1 999 1 1023 1024 Amplitude values are not calibrated The input laser line s generate an interference pattern on the photodetector as a function of the Michelson interferometer o
107. ed When used with a SCALar command a single value is returned The display is placed in the single wavelength mode and the marker is placed on the signal having a power level that is closest to the lt expected_value gt parameter When used with an ARRay command an array of amplitudes is returned The display is placed in the list by power mode Returned values are in the current power units Wavelength units are not affected CONFigure command When this function is used with the CONFigure command the query question mark char acter must not be included in the string However the FETCh READ and MEASure command are queries and require the question mark Refer to the examples for this com mand MAXimum Displays the highest power signal MINimum Displays the lowest power signal DEFault Displays the signal at the current marker position Examples Query Response Programming Commands Measurement Instructions CONF ARR POW ETC SCA CONF SCAL IF i POW MAX READ SCAL MEAS SCAL FETC ARR POW READ ARR POW MEAS ARR POW POW 10 dBm POW MIN POW DEF The following line is an example of a returned string when MEAS SCAL POW MAX is sent 5 88346500E 000 If six laser lines are located and MEAS ARR POW is sent the following string could be returned Notice that the first returned number indicates the number of laser line values returne
108. ed CONFigure command When this function is used with the CONFigure command the query question mark char acter must not be included in the string However the FETCh READ and MEASure command are queries and require the question mark Refer to the examples for this com mand MAXimum The highest frequency signal MINimum The lowest frequency signal DEFault The current marker position 4 18 Programming Commands Measurement Instructions lt resolution gt MAXimum 0 01 resolution fast update Constants s MINimum 0 001 resolution normal DEFault Current resolution Examples CONF ARR POW FREQ DEF MIN FETC ARR POW FREQ DEF MAX READ ARR POW FREQ MEAS ARR POW FREQ CONF SCAL POW FREQ 230 8THZ MAX FETC SCAL POW FREQ 230 8THZ MIN READ SCAL POW FREQ 230 8THZ MEAS SCAL POW FREQ 230 8THZ Query Response The following line is an example of a returned string when MEAS SCAL POW FREQ MAX is sent 1 94055176E 014 If six laser lines are located and MEAS ARR POW FREQ is sent the following string is an example of the returned data Notice that the first returned num ber indicates the number of laser line values returned in the query 6 1 94055100E 014 1 93854100E 014 1 93653000E 014 1 934520 00E 014 1 93250900E 014 1 93050000E 014 4 19 Syntax Description lt expected value gt Constants Programming C
109. eference For the CALC3 DATA query the power data returned is the array of absolute powers measured for each laser line The frequency data is the array of fre quency values normalized to the frequency of the reference laser line The fre quency of the reference laser line is returned as an absolute frequency unnormalized Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments 4 42 Syntax Attribute Summary Description Programming Commands CALCulate3 Subsystem DELTa WPOWer STATe Turns the delta wavelength and power measurement mode on and off CALCulate3 DELTa WPOWer STATe ON OFF 1 O Preset State off RST State off SCPI Compliance instrument specific When on the wavelength of the reference laser line is subtracted from the wavelength values of all laser lines except the reference The power value of the reference is subtracted from the power values of all laser lines except the reference For the CALC3 DATA query the power data returned is the array of powers normalized to the power of the reference laser line The power of the refer ence laser line is returned as an absolute power unnormalized The frequency data is the array of frequency values normalized
110. elengths are present these individual responses with the reduced resolution may no longer be recognized Select continuous or single measurements The HP 86120A continuously measures the input spectrum at the front panel OPTICAL INPUT connector Whenever measurements are being acquired an asterisk is displayed in the display s upper right corner When you switch between normal and fast update modes the rate that the asterisk blinks changes Making Measurements Changing the Units and Measurement Rate You can specify that the instrument perform a measurement only when the front panel Single key is pressed This is the single acquisition measurement mode and it is useful for capturing and preserving data After capturing the data you can display it using many of the procedures included in this chapter You can return to continuous measurement mode at any time by pressing the Cont key To change the units of measure 1 Press Setup 2 Press the UNITS softkey 3 Press WL and select one of the following units Then press RETURN to complete your selection e NM for nanometers e 7HZ for terahertz e CM7 for wave number 4 Press POWER and select one of the following units e DBM for decibels relative to a milliwatt e MW for milliwatts e UW for microwatts To select single measurement acquisition e Press the Single key Making Measurements Changing the Units and Measurement Rate To increase measurement
111. ence of a summary bit from other registers or queues Notice in the following figure that the bits in the Standard Event Sta tus OPERation status and QUEStionable status registers are or d to control a bit in the Status Byte Register If a bit in the Status Byte Register goes high you can query the value of the source register to determine the cause 3 17 Programming Monitoring the Instrument QUEStionable Status not used not used not used POWer not used not used not used not used not used Maximum Signals Drift Reference Delta Reference not used not used Command Warning not used not used SETTling RANGing not used MEASuring not used not used not used not used Processing Hardcopy not used not used not used not used not used Operation Complete Request Control Query Error Device Dependent Error Execution Error Command Error User Request Power On 0 1 2 3 4 5 6 7 8 9 Standard Event Status Register y Error Event Queue Status Byte o 1 2 3 MAV 4 5 RQS 6 7 status 3 18 Programming Monitoring the Instrument The Status Byte Register can be read using either the STB common com mand or the HP IB serial poll command Both commands return the decimal weighted sum of all set bits in the register The difference between the two methods is that the serial poll command reads bit 6 as the Request Service RQS bit and clears the bit which clears t
112. ential commands to ensure that your programs execute properly Programming Making Measurement S For example suppose that you wanted to set the elevation correction value and then send an INIT IMM command The following programming fragment results in an error 213 Init ignored This occurs because the ELEVation command causes the recalculation of the data which is like sending the INIT IMM command When the actual INIT IMM is sent the error occurs because the command is already in progress OUTPUT 720 INI7 OUTPUT 720 SENSe CORRection E l IMM OUTPUT 720 INI7 Use an OPC query to ensure that the F as shown in the following lines l IMM OUTPUT T2073 INIT TAI OUTPU OUTPUT 720 IKOR ENTER 720 Responses OUTPUT 7203 sINiITsT Or the WAI command c OUTPUT 720 INIT I1 OUTPU OUTPU 720 WAI OUTPUT 720 INIT 1 m 720 SENSe CORRection EF uld be used m 720 SENSe CORRection E m EVation 1000 LEVation command has completed EVation 1000 EVation 1000 3 14 Programming Making Measurements The format of returned data Measurements are returned as strings All measurement values are returned from the HP 86120A as ASCII strings When an array is returned the individual values
113. ents Measuring Wavelength and Power To use the full wavelength range 1 Press the Setup key 2 Press MORE and then WL LIM 3 Press LIM OFFto remove the limits on wavelength range All responses in the full 700 nm to 1650 nm range are now displayed To control the power bar 1 Press the Setup key 2 Press MORE and then PWR BAR 3 Press BAR ON to display the power bar and press BAR OFF to hide the power bar display 2 9 Making Measurements Changing the Units and Measurement Rate Changing the Units and Measurement Rate Change the displayed units As described later in this section it s easy to change the wavelength and amplitude units You can choose between the following units Table 2 1 Available Units Wavelength Power nm dBm cm mW THz uw You can speed up the measurement rate Under normal operation the HP 86120A makes a measurement and displays the results about once every 1 25 seconds It is in this normal update mode that maximum accuracy and wavelength resolution are achieved However should a faster update be desired for example when real time feedback is required to tune a laser to its designated channel the HP 86120A can be set to update approximately four times per second This reduces both wavelength resolution and accuracy but can be beneficial in some applications When FAST update is selected one less digit of resolution is displayed Also if multiple wav
114. er values for the same measurement This is shown in the following program fragment OUTPUT 720 INIT CONT OFF OUTPUT 720 CONF ARR POW MAX OUTPUT 720 INIT IMM OUTPUT 720 FETC ARR POW ENTER 720 powers OUTPUT 720 FETC ARR POW WAV ENTER 720 wavelengths 3 11 Programming Making Measurements In the example above the data in the power and wavelength arrays are returned in the same order so that powers can be matched to wavelengths Also because new data is not collected FETCh is especially useful when char acterizing transient data FETCh does not reconfigure the display For example if the display is in the Peak WL mode sending FETCh ARRay does not configure the display to the List by WL even though an array of data is returned to the computer A common programming error occurs when the FETCh command is used after an RST command This generates error number 230 Data corrupt or stale In this instance you must send INIT IMM after the RST command and before FETCh command to capture a new array of measurement data CONFigure command The CONFigure command changes measurement settings without taking a measurement The instrument is placed in the List by WL List by Ampl Peak WL display or in the coherence length application CONFigure can be queried The query returns the last configuration setup by the CONFigure comma
115. erating status This includes querying execution or command errors and determining whether or not measurements have been completed Several sta tus registers and queues are provided to accomplish these tasks In this section you ll learn how to enable and read these registers In addition to the information in this section you should review the commands docu mented in Common Commands on page 4 4 and STATus Subsystem on page 4 66 Programming Monitoring the Instrument Status registers The HP 86120A provides four registers which you can query to monitor the instrument s condition These registers allow you to determine the following items e Status of an operation e Availability of the measured data e Reliability of the measured data All three registers are shown in the figure on the following page and have the following uses Register Definition Status Byte Monitors the status of the other three registers Standard Event Status This is the standard IEEE 488 2 register Con tains bits which indicate the status of the other two registers OPERation Status Contains bits that report on the instrument s normal operation QUEStionable Status Contains bits that report on the condition of the signal Status Byte register The Status Byte Register contains summary bits that monitor activity in the other status registers and queues The Status Byte Register s bits are set and cleared by the presence and abs
116. erface with angled physical contact interface Option 900 Great Britain power cord 1 8120 1703 Option 901 Australia New Zealand China power cord 8120 0696 Option 902 European power cord 1 8120 1692 Option 906 Switzerland power cord 8120 2296 Option 912 Denmark power cord 1 8120 2957 Option 917 India South Africa power cord 1 8120 4600 Option 918 Japanese power cord 8120 4754 Option 919 Israel power cord 1 8120 5181 Option UK5 Protective soft carrying case 1 Option UK6 Commercial calibration certificate with 1 calibration data Option AXE Rack mount kit with handles 1 86120 60031 Option IX4 Rack mount kit without handles 1 86120 60030 Option OB2 Additional user s manual 1 86120 90001 Option 412 Add 10 dB external attenuator FC PC 1 interface connector 1 5 Getting Started Step 2 Check the Fuse ee Step 2 Check the Fuse 1 Locate the line input connector on the instrument s rear panel 2 Disconnect the line power cable if it is connected 3 Use a small flat blade screwdriver to open the pull out fuse drawer 4 Verify that the value of the line voltage fuse in the pull out drawer is correct The recommended fuse is an IEC 127 5x20 mm 6 3A 250 V HP part number 2110 0703 Notice that an extra fuse is provided in a drawer located on the fuse holder WARNING For continued protection against fire hazard replace line fuse only with same type and ratings type T 6 3A 25
117. ery Since this command places the instrument in sin gle measurement acquisition mode any current data is marked as invalid and a measurement query such as FETCh results in error number 230 Data corrupt or stale You must initiate a new sweep with INIT IMM before you can use the FETCh command 4 8 Programming Commands Common Commands Table 4 4 Conditions Set by RST Reset Item Setting Display mode single wavelength Wavelength range limiting on Measurement acquisition single Wavelength calibration vacuum Elevation correction value 0 meters Wavelength units nm Amplitude units dBm Amplitude offse 0dB Peak threshold 10 dB Peak excursion 15 dB Number of uncorrected data points 34123 Power bar display on Delta Measurements A power 0 A wavelength 0 A wavelength and power o reference signal position 700 nm Drift measurements 0 Signal to Noise Measurements measurement 0 reference frequency 193 4144 THz reference wavelength 1550 nm in vacuum 4 9 Programming Commands Common Commands SRE The SRE service request enable command sets the bits in the service request enable register Syntax SRE lt integer gt SRE lt imteger gt is defined as an integer mask from 0 to 255 Description The service request enable register contains a mask value for the bits to be enabled in the status byte register A bit set to on
118. es the absolute reference values for the laser line indicated by the cursor The reference values are measured before the measurement starts 8 888rnm 8 8906 DRIFT ig 5 BH 4 16 EY WL 4 868 H 11 1551 2314 OF 6E A 69a f 09 6 37 ae 5 BBH B iil a M drift You can restart the drift measurement at any time by pressing the RESET soft key All minimum and maximum values are reset to the reference values and the HP 86120A begins to monitor drift from the current laser line values Move the cursor up and down the listing to see the reference wavelength and power of each laser line Making Measurements Measuring Laser Drift lf measurement updating stops or the values become blanked If in the middle of a measurement the number of laser lines present changes the mea surement stops until the original number of lines returns You ll notice that a CLEAR soft key appears and one of the following message is displayed E46 NUM LINES lt NUM REFS E47 NUM LINES gt NUM REFS To view the data measured before the conditions changed press CLEAR and then MAX MIN Notice that the measurement acquisition is changed from continuous to single To restart testing press CLEAR the CONT key and then RESET to use the new number of lines as the reference Pressing CONT restarts continuous measurement acquisition Or you can restore the original number of lines on the input so that the drift measurement ca
119. es to process the data but does not place it in the output buffer Because of the amount of data processed the instrument will not respond to any new commands in its input buffer for up to 20 seconds 4 27 Syntax Attribute Summary Description Programming Commands CALCulate1 Subsystem TRANsform FREQuency POINts Sets the size of the fast fourier transform FFT performed by the instrument CALCulatel TRANsform FREQuency POINTs lt integer gt MINimum MAXimum lt integer gt Sets FFT size Must be either 34123 or 4268 Other values result in an error Constant Description MINimum 4 268 MAXimum 34 128 Non sequential command Preset State array size set to 34 123 RST State 34 123 SCPI Compliance instrument specific A NORMAL updated display corresponds to an FFT size of 34 123 A FAST updated display corresponds to an FFT size of 4 268 These values are a sub set of the uncorrected data buffer shown in the figure that is located in Mak ing Measurements on page 3 6 Changing the number of points causes the instrument to reprocess the current set of data The query form of the command returns the number of points in the data set This is the number of measurement points that will be returned by the CALC1 DATA query Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrumen
120. esulting from delta drift and signal to noise measurements CALCulate3 DATA POWer FREQuency WAVelength WNUMber Argument Description POWer Queries the array of laser line powers after the calculation is completed FREQuency Queries the array of laser line frequencies after the calculation is completed WaAVelength Queries the array of laser line wavelengths after the calculation is completed WNUMber Queries the array of laser line wave numbers after the calculation is completed Preset State not affected SCPI Compliance standard Query Only The data returned by the query depends upon which calculation state is on If no calculation state is on an error is generated The returned data is comma delimited The following string is a typical example of six values returned when POWer is specified from a delta power measurement 7 42833100 3 41918900 000 1 000872001 000 3 804372001 000 2 52121400E 000 6 36282900E 000 000 ry E an E Bi A Notice that only measurement values are returned to the computer There is no first value that indicates the number of values contained in the string as there is for example with the FETCh READ and MEASure commands Use the CALC3 POIN query to determine the number of points the CALC3 DATA query returns 4 38 Syntax Attribute Summary Description Syntax Attribute Summary Programming Commands CALCulate3 Subsy
121. ets the elevation value used by the instrument to compensate for air disper sion SENSe CORRection ELEVation lt integer gt MINimum MAXimum lt imteger gt is the altitude in meters Constant Description MINimum Om MAXimum 5000 m Non sequential command Preset State unaffected by RST sets this value to the minimum SCPI Compliance instrument specific Changing the elevation value causes the current data to be reprocessed The query form returns the current elevation setting as shown in the following example 1500 Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrument Refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 for more information 4 62 Syntax Attribute Summary Description Syntax Programming Commands SENSe Subsystem CORRection MEDium Sets the HP 86120A to return wavelength readings in a vacuum or standard air SENSe CORRection MEDium AIR VACuum Argument Description AIR Selects wavelength values in standard air VACuum Selects wavelength values in a vacuum Preset State VAC RST State VAC SCPI Compliance instrument specific Standard air is defined to have the following characteristics Barometric pressure 760 torr Temperature 15 C Relative humidity 0 CORR
122. ey Equivalent Command THZ MEASure ARRay POWer FREQuency UNITS UNIT POWer UPDATE Measurement Instructions and CALCulate1 TRANsform FREQuency POINts USER CALCulate3 SNR AUTO OFF USER WL CALCulate3 SNR REFerence WAVelength UW UNIT POWer VACUUM SENSe CORRection MEDium VACuum WL See CM NM and THZ WL LIM CALCulate2 WLIMit STATe WL REF See AUTO USER and USER WL Programming Lists of Commands Programming Commands Programming Commands Programming Commands Programming Commands This chapter is the reference for all HP 86120A programming commands Commands are organized by subsystem Table 4 1 Notation Conventions and Definitions Convention Description lt gt Angle brackets indicate values entered by the programmer Or indicates a choice of one element from a list Square brackets indicate that the enclosed items are optional When several items are enclosed by braces one and only one of these elements must be selected lt integer gt An ASCII string representing an integer This is defined by the IEEE 488 2 lt NR1 gt format lt real gt An ASCII string representing a real number This is defined by the IEEE 488 2 lt NR2 gt or lt NRf amp formats 4 2 Contents Programming Commands Programming Commands Common Commands 4 4 Measurement Instructions 4 14 CALCulatel Subsystem 4 25 CALCulate2 Subsystem 4 30 CALCulate3 Subsystem 4 36 CONFig
123. following safety symbols are used throughout this manual Familiarize yourself with each of the symbols and its meaning before operating this instru ment The caution sign denotes a hazard to the instrument It calls attention to a procedure which if not correctly performed or adhered to could result in damage to or destruction of the instrument Do not proceed beyond a caution sign until the indicated conditions are fully understood and met The warning sign denotes a life threatening hazard It calls attention to a procedure which if not correctly 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 manual symbol The product 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 This symbol denotes that the instrument uses alternating current A AX These symbols denotes that the power supply is turned on O oOo These symbols denotes that the power supply is turned off ce The CE mark is a registered trademark of the European Community ISM1 A This text denotes that the instrument is an Industrial Scientific and Medical Group 1 Class A product The CSA mark is a registered trademark of the Can
124. g connectors Servicing Testing Performance Test 4 Optical Input Return Loss Input return loss is verified using the following devices HP 8153A Lightwave Multimeter HP 81553SM 1550 nm Fabry Perot laser SM 9 125 um Source Module HP 81534A Return Loss Model Turn the source module s output off 2 Connect a single mode patchcord between the source module s optical 10 Connect the HMS 10 HP HRL to FC PC patchcord to the HP 86120A s front 1 j 12 output and the return loss module s INPUT SOURCE connector Set the return loss module s wavelength to 1550 nm and select an average time of 1 second Locate an HMS 10 HP HRL to FC PC patchcord Connect the HMS 10 HP HRL end of the patchcord to the return loss module s OUTPUT connector Terminate the other end of the cable Zero the return loss module Turn on the source module Remove the termination from the cable and leave the cable s free end uncovered The return loss module measures the reflection reference 14 6 dB return loss of the patchcord s FC PC connector in air Make a low reflection termination in the HMS 10 HP HRL to FC PC patchcord Do this by wrapping the cable 6 times around a 5 mm diameter mandrel The return loss module measures the termination parameter panel OPTICAL INPUT connector The lightwave multimeter measures the return loss Compare this measurement with the specification listed in Chapter 6 Specific
125. g responses are returned as upper case letters Queries usually take the form of a command followed by a question mark After receiving a query the instrument places the answer in its output queue The answer remains in the output queue until it is read or another command is issued For example the query OUTPUT 720 CALCULATE2 POINTS places the number of points in the data set in the output queue In HP BASIC the controller input statement ENTER 720 Range passes the value across the bus to the controller and places it in the variable Range A newline character is appended to the response Sending another command or query before reading the result of a query causes the output queue to be cleared and the current response to be lost This also generates an error in the error queue The output of the instrument may be numeric or character data depending on what is queried Refer to the specific commands for the formats and types of data returned from queries You can send multiple queries to the instrument within a single program mes sage but you must also read them back within a single program message This can be accomplished by either reading them back into a string variable or into multiple numeric variables When you read the result of multiple queries into string variables each response is separated by a semicolon 3 28 Programming Programming Example Programs Example Programs Th
126. g the Units and Measurement Rate 2 10 To change the units of measure 2 11 To select single measurement acquisition 2 11 To increase measurement speed 2 12 Defining Laser Line Peaks 2 13 To define laser line peaks 2 16 Measuring Laser Separation 2 18 To measure channel separation 2 20 To measure flatness 2 20 Measuring Laser Drift 2 21 To measure drift 2 23 Measuring Signal to Noise Ratios 2 25 To measure signal to noise 2 28 Measuring Coherence Length 2 29 To measure coherence length 2 31 Measuring Modulated Lasers 2 32 Measuring Total Power Greater than 10 dBm 2 33 To measure total power exceeding 10 dBm 2 33 Calibrating Measurements 2 34 To enter the elevation 2 35 To select the medium for light 2 35 Printing Measurement Results 2 36 To create a hardcopy 2 37 Cleaning Connections for Accurate Measurements 2 38 To clean a non lensed connector 2 40 To clean an adapter 2 41 To test insertion loss and return loss 2 41 2 3 Making Measurements Measuring Wavelength and Power Measuring Wavelength and Power This section gives you step by step instructions for measuring peak wave length average wavelength peak power and total input power There are three display modes e Peak wavelength e List by wavelength or power e Average wavelength and total power The figure on this page shows the peak wavelength mode The figure on the next page shows the list by wavelength display mode where the signals are displayed in order from
127. ges of which three are used in the instrument 5 2V 15V and 15V These voltages are con nected to the A5 Main Board Assembly at A5J6 and then distributed to the instrument s various circuits and assemblies The Al Optical Block Assembly contains a Michelson interferometer and a ref erence HeNe laser The A5 Main Board Assembly provides motor control analog to digital con version signal processing and power supply distribution The motor control includes the motor drive and encoder counter for the motor located in the Al Optical Block Assembly Because these motor controls are interactive isolat ing the malfunction to one of these circuits is best done by substituting known good Al or A5 assemblies The troubleshooting procedures in this section refer to the connector jacks on the A5 Main Board Assembly The following figure shows the location of each of these jacks J6 J9 J7 J8 Bottom View J14 J13 J10 J11 J1 J12 J2 No O 5 2 a E a L 2 2 2 A5 Assembly Jacks Servicing Troubleshooting J3 J4 J5 5 15 Servicing Troubleshooting If a general problem occurs 1 Test the power supply voltages as described in To check the power supply voltages on page 5 17 2 Test the Al Optical Block Assembly as described in
128. he CALCulate3 commands to perform delta drift and signal to noise measurements To select a measurement use one of the following STATe com mands CALC3 DELT POW STAT delta power CALC3 DELT WAV STAT delta wavelength CALC3 DELT WPOW STAT delta power and wavelength CALC3 DRIF STAT drift CALC3 SNR STAT signal to noise ratios If you select a drift measurement you can additionally select one of the fol lowing additional states CALC3 DRIF DIFF STAT difference CALC3 DRIF MAX STAT maximum drift CALC3 DRIF MIN STAT minimum drift CALC3 DRIF REF STAT drift reference values The CALCulate3 DRIFt PRESet command turns off the minimum maximum difference and reference states but leaves the drift state on Attempting to turn more than one state on at a time results in a 221 Settings Conflict error The RST and SYSTem PRESet commands turns all calculations off Programming Commands CALCulate3 Subsystem The commands in this subsystem have the following command hierarchy CALCulate3 DATA DELTa POWer STATe PRESet REFerence FREQuency POWer WAVelength WNUMber WAVelength STATe WPOWer STATe DRIFt DIFFerence REFerence RESet STATe STATe POINts SNR AUTO REFerence FREQuency WAVelength WNUMber STATe 4 37 Syntax Attribute Summary Description Programming Commands CALCulate3 Subsystem DATA Queries the data r
129. he SRQ interrupt The STB com mand reads bit 6 as the Master Summary Status MSS and does not clear the bit or have any affect on the SRQ interrupt The value returned is the total bit weights of all of the bits that are set at the present time OPERation Status and QUEStionable Status registers You can query the value of the OPERation Status and QUEStionable Status registers using commands in the STATus subsystem The STATus subsystem also has transition filter software which give you the ability to select the logic transitions which set bits in the OPERation Status and QUEStionable Status registers For example you can define the POWer bit of the QUEStionable Status register to report an event when the condition transitions from false to true This is a positive transition You can also specify a negative transition where the bit is set when the condition transitions from true to false Table 3 3 Bits in Operation Status Register Bit Definition 0 not used 1 SETTling indicating that the instrument is waiting for the motor to reach the proper position before beginning data acquisition 2 RANGing indicating the the instrument is currently gain ranging 3 not used 4 MEASuring indicating that the instrument is making a measurement 5 through 8 not used g Processing indicating that the instrument is currently processing the data acquired 10 Hardcopy indicating that the instrument is currently pr
130. he first four characters of the keyword unless the fourth character is a vowel in which case the mnemonic is the first three char acters of the keyword This rule is not used if the length of the keyword is exactly four characters Table 3 5 Examples of Short Forms Long Form Equivalent Short Form ROUTE ROUT LAYER LAY SYSTEM SYST ERROR ERR You can use upper or lowercase letters Program headers can be sent using any combination of uppercase or lower case ASCII characters Instrument responses however are always returned in uppercase Combine commands in the same subsystem You can combine commands from the same subsystem provided that they are both on the same level in the subsystem s hierarchy Simply separate the com mands with a semi colon For example the following two lines OUTPUT 720 CALC2 PEXC 12 OUTPUT 720 CALC2 PTHR 20 can be combined into one line OUTPUT 720 CALC2 PEXC 12 PTHR 20 The semicolon separates the two functions Combine commands from different subsystems You can send commands and program queries from different subsystems on the same line Simply precede the new subsystem by a semicolon followed by a colon In the following example the colon and semicolon pair before DISP allows you to send a command from another subsystem OUTPUT 720 CALC2 PEXC 12 DISP WIND GRAP STAT OFF 3 25 Programming Reviewi
131. hen the ARRay command is used multiple data values are returned The MEASure measurement instruction always acquires new measurement data In order to obtain both wavelength and power values from the same mea surement data use two FETCh commands This is shown in the following pro gram fragment OUTPUT 720 INIT CONT OFF OUTPUT 720 CONF ARR POW MAX OUTPUT 720 INIT IMM OUTPUT 720 FETC ARR POW ENTER 720 powers OUTPUT 720 FETC ARR POW WAV ENTER 720 wavelengths In the example above the data in the power and wavelength arrays are returned in the same order so that powers can be matched to wavelengths You can also send a MEASure command followed by a FETCh command 4 14 Programming Commands Measurement Instructions The commands in this subsystem have the following command hierarchy MEASure READ FETCh CONFigure ARRay SCALar POWer FREQuency WAVelength WNUMber SCALar LENGth COHerence ALPHa BETA CLENgth DELay 4 15 Syntax Description lt expected value gt Constants Programming Commands Measurement Instructions MEASure ARRay SCALar POWer Returns amplitude values POWer lt expected_value gt lt resolution gt Used With lt expected_value gt lt resolution gt SCALar optional ignored ARRay ignored ignor
132. ical Block Assembly exchange A1A1 Interferometer Part of A1 Can not be ordered separately A1A2 Detector Part of A1 Can not be ordered separately A143 Laser Part of A1 Can not be ordered separately A2 09802293 PowerSupplyBoardAssembly A3 09503024 High Voltage Power Supply Assembly A4 1150 5006 Digital Signal Processing Board Assembly A5 86120 60011 Main Board Assembly 86120 69011 Main Board Assembly exchange A6 86120 60025 Front Panel Assembly includes A6A2 Does not include A6A1 86120 69025 Front Panel Assembly includes A6A2 Does not include A6A1 exchange A6A1 2090 0292 Display Assembly includes printed circuitboard A6A2 86120 40001 Flexible keypads Pulls apart along groove into two separate pads B1 5063 0243 Fan Assembly FL1 9135 0270 Line Module Filter Also part of W12 5 46 Servicing Replaceable Parts A3 A6A2 Top View G OGo000 B A6 a See A2 SOS a s A6A1 See A1A3 A1A1 A1A2 Bottom View A5 FL1 ie D G H o o o B1 o fo A4 5 r 5 C rpmajoi 5 47 Servicing
133. iew 6 12 returning for service 1 15 state when turned on 4 75 7 3 internal labels 5 7 L labels internal 5 7 laser aperture 1 11 classification 6 10 drift iv 2 21 2 23 line separation iv 2 18 linewidth 2 2 modulated 2 32 tuning power 2 5 warning label 5 7 LEFT programming command 4 54 LIM OFF softkey 1 14 2 9 LIM ON softkey 1 14 2 9 LINE key 1 10 linearity 6 4 6 7 line power cable 1 7 cables 7 19 filter assembly replacing 5 42 Index 3 Index initial state 4 75 7 3 input connector 1 6 5 19 requirements 1 7 specifications 6 9 linewidth 2 2 List by Power menu map 7 7 mode 3 11 softkey 2 8 2 23 List by WL key 2 5 menu map 7 8 mode 3 11 softkey 2 8 2 23 LOCAL softkey 3 4 long form commands 3 24 lowercase letters 3 25 low power laser lines 2 16 M M annotation 2 5 MAGNitude programming command 4 63 MAX NUMBER OF SIGNALS FOUND 2 17 maximum power input v MAXimum programming command 4 54 MAX MIN softkey 2 23 MEASure measurement instruction 3 32 3 34 4 14 measurement accuracy 1 3 air in 2 34 AM modulation 2 13 2 32 audio modulation effects of 2 13 2 32 average wavelength 2 6 calibration 2 34 channel separation 2 20 channel spacing 2 19 coherence length 2 29 continuous acquisition 2 10 cycle time 6 5 6 8 definition of peaks 2 13 elevation effects of 2 34 flatness 2 20 via HP IB 3 6 instructions 3 23 4
134. ifications and Regulatory Information Specifications Specifications Each laser line is assumed to have a widewith including modulation side bands of less than 10 GHz All specifications apply when the instrument is in NORMAL UPDATE mode unless noted Wavelength Range Absolute accuracy lines separated by 230 GHz Differential accuracy characteristic Minimum resolvable separation characteristic Display resolution 700 1650 nm 182 428 THz 3 ppm 0 005 nm at 1550 nm 0 004 nm at 1310 nm 2 ppm 20 GHz 0 16 nm at 1550 nm 0 11 nm at 1300 nm 0 001 nm normal update mode 0 01 nm fast update mode a Signals of equal amplitude For lines that are separated by less than 30 GHz wavelength accuracy is reduced 6 6 Specifications and Regulatory Information Specifications Amplitude Calibration accuracy at calibration wavelengths 30 nm 1310 and 1550 nm 0 5 dB 780 nm characteristic 0 5 dB Flatness 30 nm from any wavelength 1200 1600 nm characteristic 0 2 dB 700 1650 nm characteristic 0 5 dB Linearity 1200 nm to 1600 nm lines above 20 dBm 0 3 dB Polarization dependence 1200 1600 nm 0 5 dB 700 1650 nm characteristic 1 0 dB Display resolution 0 01 dB Sensitivity 700 900 nm single line input 20 dBm 900 1200 nm single line input 25 dBm 1200 1600 nm single line input 35 dBm 1600 1650 nm single line input 30 dBm 700 1650 nm multiple l
135. ightwave component analyzer HP 8702 analyzer with the appropriate source receiver and lightwave cou pler HP 8504 precision reflectometer HP 8153 lightwave multimeter with a source and power sensor module in conjunction with a lightwave coupler HP 81554SM dual source and HP 81534A return loss module Programming Programming Programming Programming This chapter explains how to program the HP 86120A The programming syn tax conforms to the IEEE 488 2 Standard Digital Interface for Programmable Instrumentation and to the Standard Commands for Programmable Instru ments SCPI Where to begin e Ifyou are unfamiliar with the rules governing SCPI command syntax refer to Reviewing SCPI Syntax Rules on page 3 23 e To learn how to correctly begin your programs refer to Addressing and Ini tializing the Instrument on page 3 4 e To learn which commands to use and how to use them refer to Making Measurements on page 3 6 e To learn to read the instrument s status registers refer to Monitoring the Instrument on page 3 16 The programming examples for individual commands in this manual are writ ten in HP BASIC 6 0 for an HP 9000 Series 200 300 Controller 3 2 Contents Programming Programming Addressing and Initializing the Instrument 3 4 To change the HP IB address 3 5 Making Measurements 3 6 Commands are grouped in subsystems 3 8 Measurement instructions give quick resu
136. ines input characteristic 30 dB below total input power but not less than single line input sensitivity a Spurious free from 10 dBm to 20 dBm 6 7 Specifications and Regulatory Information Specifications Selectivity Two lines input separated by 2100 GHz characteristic Two lines input separated by gt 30 GHz characteristic Input Power Maximum displayed level sum of all lines Maximum safe input level sum of all lines Maximum Number of Laser Lines Input Input Return Loss 25 dB 10 dB 10 dBm 18 dBm 100 With flat contacting connectors With angled contacting connectors Option 022 35 dB 50 dB Measurement Cycle Time Normal update mode characteristic Fast update mode characteristic 1 25 s 0 8 measurements per second 0 25 s 4 measurement per second Measurement Applications Signal to Noise characteristic Coherence Length characteristic gt 25 dB 1 nm noise bandwidth lines above 20 dBm Fabry Perot lasers 1 to 200 mm coherence length accuracy 5 0 75s cycle time 6 8 Operating Specifications Specifications and Regulatory Information Specifications Use Power Voltage Frequency Altitude Operating temperature Maximum relative humidity Weight Dimensions H x W x D indoor 115 VAC 110 VA MAX 60 WATTS MAX 1 1 A MAX 230 VAC 150 VA MAX 70
137. ing the laser high voltage connector ground the two contacts of the male connector simultaneously to discharge the plasma tube This label warns you about disconnecting the high voltage connector to the A1A3 Laser Assembly Be sure to properly discharge the connector as described in the procedure To replace the A1 Optical Block Assembly on page 5 32 or To replace the A3 High Voltage Power Supply Assembly on page 5 37 WARNING HAZARDOUS VOLTAGE This label warns you of hazardous voltages associated with the A3 High Voltage Power Supply Assembly AUA CAUTION PRODUCT WARRANTY WILL BE VOID IF THIS COVER REMOVED Hewlett Packard 86120A 600010 SN 001 Lightwave Operation Santa Rosa CA 95403 Made in USA of domestic And foreign components This label has to purposes First it warns you that the instrument s warranty will be voided if the cover on the A1A1 Interferometer Assembly is disturbed Second if the cover is disturbed the label will be damaged to indicate the tampering Never remove this cover This label provides the HP part number and serial number for the A1A1 Interferometer Assembly 5 7 Servicing General Information Table 5 3 Major Assemblies Reference Desiqnator Description Al Optical Block Assembly A1A1 Interferometer Part of A1 A1A2 Detector Part of A1 A1A3 Laser Part of A1 A2 Power Supply Board A
138. inting the data to the parallel port 11 through 16 not used 3 19 Programming Monitoring the Instrument Table 3 4 Bits in Questionable Status Register Bit Definition 0 1 and 2 not used 3 POWer indicating that the instrument is measuring too high of a power 3 through 8 not used 9 Maximum signals indicating that the instrument has found the maximum number of signals 0 Drift Reference indicating that the number of reference signals is different from the current number of input signals 1 12 through 13 Delta Reference indicating that there is no delta reference signal not used 4 Command Warning indicating that the instrument has received some extra unexpected parameters for one of the measurement functions 5 not used Standard Event Status register The Standard Event Status Register monitors the following instrument status events OPC Operation Complete RQC Request Control QYE Query Error DDE Device Dependent Error EXE Execution Error CME Command Error URQ User Request PON Power On When one of these events occur the event sets the corresponding bit in the register If the bits are enabled in the Standard Event Status Enable Register the bits set in this register generate a summary bit to set bit 5 ESB in the Status Byte Register The contents of the Standard Event Status Register can be read and the regis ter
139. is FNIdentity D E Current_pwr 1 Nb_wl OUTPUT Mwm INIT CONT OFF ON TIMEOUT 7 5 CALL Err_mngmt OUTPUT Mwm MEAS ARR POW WAV ENTER Mwm USING K Nb_wl ALLOCATE Current_wl 1 Nb_wl ENTER Mwm USING K Current_wl OUTPUT Mwm FETC ARR POW ENTER Mwm USING K Nb_wl LOC R N Mwm USING K Current_pwr OR I 1 TO Nb_wl PRINT USING 22A 2D 6A 4D 2DE 4A S2D 2D 3A The wavelength number Current_wl I at Current_pwr I dBm EXT I OFF TIMEOUT STOP Error_msg PRINT the prgm is aborted due to ERRMS END 3 34 Programming Example Programs Err_mngmt SUB Err_mngmt COM Instrument Mwm DIM Err_msg 255 INTEGER Cme CLEAR 7 REPEAT OUTPUT Mwm ESR ENTER Mwm Cme OUTPUT Mwm SYST ERR ENTER Mwm Err_msg PRINT Err_msg UNTIL NOT BIT Cme 2 AND NOT BIT Cme 4 AND NOT BIT Cme 5 AND Err 0 Subend SUBEND UHH Set_ese SUB Set_es COM Instrument Mwm OUTPUT Mwm ESE IVAL 00110100 2 SUBEND Identity DEF FNIdentity COM Instrument Mwm DIM Identity 50 Identity OUTPUT Mwm RST OUTPUT Mwm OPC F ER Mwm Opc_done OUTPUT Mwm IDN ER Mwm Identity URN Identity
140. is above the peak threshold level relative to the fundamental line it is considered a peak Its dis played power level may be greater than that of the fundamental because the amplitude correction at 775 nm is much greater by about 15 dB than that at 1550 nm the interfer ometer is less sensitive at 775 nm To avoid displaying this second harmonic line limit the input wavelength range from 1200 nm to 1650 nm as described in To use the full wavelength range on page 2 9 Or reduce the peak threshold below its preset value Because the peak threshold level is used to determine which signals are to be displayed before amplitude corrections are applied the harmonic will be eliminated To define laser line peaks 1 Press the Setup key 2 Press MORE and then THRSHLD 3 Press PX EXC and enter the peak excursion value Use the softkey to select the digit that requires editing Use the i and softkeys to change the value The peak excursion value can range from 1 to 30 dB The default value is 15 dB 4 Press RETURN 5 Press PK THLD and then enter the peak threshold value The peak threshold value can range from 0 to 40 dB Setting this value to 0 dB ensures that only the peak wavelength is identified The default value is 10 dB Pressing the green PRESET key changes the peak excursion and peak threshold values to their default settings It also turns wavelength range limiting on Turning the HP 86120A s power
141. is mode their proper operation is ensured Establish the wavelength range At the start of each program be sure to establish the input wavelength range using the HP 86120A s CALCulate2 WLIMit command Setting this command to on enables the full wavelength range of the instrument If you are measur ing signals between 1200 nm and 1650 nm use this command to ensure that spurious second harmonic peaks are not identified Refer to WLIMit STATe on page 4 35 Refer also to Limiting the input wavelength range on page 2 15 To change the HP IB address Press the Setup key Press MORE and then HP IB Use the i and softkeys to change the HP IB address Press RETURN a a E 3 5 amt ae AS Miche Interferometer Programming Making Measurements Making Measurements Making measurements remotely involves changing the HP 86120A s settings performing a measurement and then returning the data to the computer The simplified block diagram of the HP 86120A shown here lists some of the avail able programming commands Each command is placed next to the instru ment section it configures or queries data from Notice that there are two buffers from which data can be queried an uncor rected data buffer and a corrected data buffer With each scan of the input wavelength range the analog to digital converter loads 65 536 data values into the uncorrected data buffer This is considered to be one measurement
142. is the number of laser lines included in the average P is the peak power of an individual laser line Power units are in Watts linear 2 6 Making Measurements Measuring Wavelength and Power The following equation shows how individual powers of laser lines are summed together to obtain the total power value n P otal L2 P i 1 where n is the number of laser lines included in the measurement P is the peak power of an individual laser line Power units are in Watts linear Measuring lasers between 700 nm and 1200 nm After the Preset key is pressed the input wavelength range is limited to mea suring lasers between 1200 nm and 1650 nm This prevents the accidental dis play of spurious signals that may not exist You can easily expand the input range to the full 700 nm to 1650 nm range however you should learn how to identify spurious signals Spurious signals below 1200 nm may be displayed whenever low power laser lines power levels near the HP 86120A s specified sensitivity are present at the input For example a low power laser line at 1550 nm has a second har monic line at 775 nm If this second harmonic is above the peak threshold level relative to the fundamental line it is considered a peak Its displayed power level may be greater than that of the fundamental because the amplitude cor rection at 775 nm is much greater by about 15 dB than that at 1550 nm the interferometer is less sensitive at 775 nm
143. l measurements made inside the HP 86120A are performed in air the density of air due to elevation affects the wavelength results You must calibrate the HP 86120A by entering the elevation Elevations from 0 to 5000 meters can be entered The elevation correction is immediately applied to the current measurement even if the instrument is in the single measurement acquisition mode Annotation on the display shows the current calibration elevation in meters and whether the wavelength measurements are shown for a vacuum VAC or standard air STD AIR If you select frequency instead of wavelength measurements switching between vacuum and standard air will not affect the measurement results This is because the frequency of an optical signal does not change in different mediums only the wavelength changes Definition of standard air Standard air is defined to have the following characteristics Barometric pressure 760 torr Temperature 15 C Relative humidity 0 Making Measurements Calibrating Measurements To enter the elevation Press the Setup key Press the CAL softkey Press ELEV PB oon oe Use the and softkeys to enter the elevation in meters Entries jump in 500 meter steps from 0 m to 5000 m In order for the HP 86120A to meet its published specifications the eleva tion value selected with the softkeys must be within 250 meters of the ac tual elevation 5 Press RETURN to complete the entr
144. l output to the optical power meter 5 Configure the optical power meter for 1550 nm 6 Adjust the optical attenuator so that the power meter measures a power level of 0 dBm 7 Enter the attenuator setting and the measured power level in the first row of Table 5 6 on page 5 29 Be sure to enter these values into the Attenuator Settings and Power Meter Readings columns 8 Enter the measured power on the following line Pwr 9 Change the attenuator in 1 dB steps as shown in Table 5 6 and enter the attenuator settings and power measurements After completing this step the first two columns of the table should be com pletely filled in 5 26 Servicing Testing Performance 10 Disconnect the fiber optic cable from the optical power meter and connect it to the HP 86120A s OPTICAL INPUT connector 11 Set the optical attenuator for the value that you recorded in Step 8 12 Place the polarization controller in the auto scan mode 13 Press the HP 86120A s front panel Preset key 14 Press List by Power Appl s and then DRIFT 15 After two minutes stop the polarization controller s auto scan function 16 Press the MAX MIN softkey so that MAX is highlighted Enter the maximum drift reading on the following line maximum drift 17 Press the MAX MIN softkey so that MIN is highlighted Enter the minimum drift reading on the following line minimum drift 18 Use the values recorded in Step 8 S
145. late3 DATA DRIFt PS EETCH SNR READ MEASure flow2 3 7 Programming Making Measurements Commands are grouped in subsystems The HP 86120A commands are grouped in the following subsystems You ll find a description of each command in Chapter 4 Programming Commands Subsystem Purpose of Commands Measurement Instructions Perform frequency wavelength wavenumber and coherence length measurements CALCulatel Queries uncorrected frequency spectrum data CALCulate2 Queries corrected peak data CALCulate3 Performs delta drift and signal to noise measurements DISPlay Applies markers and displays power bars HCOPy Print measurement results SENSe Sets elevation correction values selects readings for air or vacuum and enters amplitude offsets Queries time domain values of the input data STATus Queries instrument status registers SYSTem Presets HP 86120A and queries error messages TRIGger Stops current measurement Acquires new measurement data Also used to select single or continuous acquisition of measurement data UNIT Sets the amplitude units to watts or dBm Table 3 1 on page 3 9 shows the kinds of measurements that the HP 86120A can perform and the associated programming commands used to return that data In some cases there is more than one method that can be used to obtain the desired data Refer to Chapter 4 Programming Commands for the cor rect syntax for these commands
146. le 7 16 DATA programming command 4 26 4 31 4 38 4 64 DBM softkey 2 11 declaration of conformity 6 11 default HP IB address 3 4 DELay programming command 4 24 Delta Off softkey See Off Delta On softkey See On dispersion See calibration measurements display annotation See annotation cursor 2 5 modes 2 4 resolution 6 4 6 7 scrolling through 2 5 Index 2 setting update rate 2 12 softkeys blanked 3 4 update rate 2 10 DISPlay subsystem 4 53 distortion 2 7 2 16 down arrow softkey 2 5 DRANge programming command 4 33 DRIFT annotation 2 21 softkey 2 23 drift laser See laser drift E E15 MAX NUMBER OF SIGNALS FOUND message 2 17 E46 NUM LINES lt NUM REFS message 2 22 E47 NUM LINES gt NUM REFS message 2 22 ELEV softkey 1 12 2 35 elevation changing feet to meters 1 12 2 35 effects of 2 34 entering 1 12 2 35 ELEVation programming command 4 62 EMI springs 5 31 ENABle programming command 4 67 EOI signal 3 27 Err_mngmt subroutine 3 31 error messages 7 12 queue 3 22 ERRor programming command 4 72 Error_msg subroutine 3 30 ESD electrostatic discharge reducing damage caused by ESD 5 13 static safe work station 5 13 ESE 3 30 4 4 ESR 4 6 EVENT programming command 4 67 4 68 event status enable register 3 30 4 5 example programs 3 30 increase source accuracy 3 44 measure DFB laser 3 32 measure FP laser 3 34 measure laser drift 3 36 measure laser separatio
147. le W13 8 Disconnect W13 from the A5 Main Board Assembly Servicing Replacing Instrument Assemblies W13 Ez g 5 o EE o O l Q o o optblkE 9 Use a T 10 TORX driver to remove the four screws that attach the A3 assembly to the instrument s side panel Four Screws optblk 5 39 Servicing Replacing Instrument Assemblies 10 To install the A3 assembly perform the steps in this procedure in reverse order 5 40 Servicing Replacing Instrument Assemblies To replace a cable clip Cable clips are used throughout the instrument to attach cables to sheet metal housings They attach with self adhesive bonds 1 Or e pa i Remove the old clip Remove any remaining glue Clean the surface using isopropyl alcohol Remove the paper backing from the bottom of the new clamp Press the clamp firmly onto the surface 5 41 WARNING Servicing Replacing Instrument Assemblies To replace line filter assembly FL1 Although replacing FL1 is straightforward be sure to observe the following points e Tighten the screws item 12 shown in Table 5 10 on page 5 52 that attach FL1 to 6 in lbs Do not use the recommended torque for M3 screws Over tightening these screws will damage line filter s flange e
148. limited to about 15 dB while measur ing lasers modulated by repetitive data formats Making Measurements Measuring Signal to Noise Ratios To measure signal to noise PO Ne Press the front panel Preset key Press List by WL Press Appl s and then S N To select the wavelength reference for measuring the noise do the following steps a Press WL REF and e press AUTO to let the instrument interpolate the wavelength or e press USER to select the last wavelength manually entered b If you chose USER you can specify the wavelength by pressing USER WL Use the softkey to select the digit that requires editing Use the amp and softkeys to change the value c Press RETURN While the signal to noise measurements are displayed you can press PEAK anytime to select the signal with the highest power Making Measurements Measuring Coherence Length Measuring Coherence Length Coherence length is a measure of the distance over which a laser s light retains the phase relationships of its spectrum The HP 86120A measures coherence length of Fabry Perot semiconductor diode lasers The HP 86120A cannot measure coherence length of light emitting diodes LEDs or distributed feed back DFB lasers When you select coherence length measurements the HP 86120A displays the following four values e Coherence length Lc e Round trip optical length of diode laser cavity 2nLd e Alpha factor e Beta f
149. lts 3 10 The format of returned data 3 15 Monitoring the Instrument 3 16 Status registers 3 17 Queues 3 22 Reviewing SCPI Syntax Rules 3 23 Example Programs 3 30 Example 1 Measure a DFB laser 3 32 Example 2 Measure a Fabry Perot laser 3 34 Example 3 Measure a Fabry Perot laser s drift 3 36 Example 4 Measure laser line separation 3 39 Example 5 Measure signal to noise ratio 3 42 Example 6 Increase a source s wavelength accuracy 3 44 Lists of Commands 3 46 3 3 Programming Addressing and Initializing the Instrument Addressing and Initializing the Instrument The HP 86120A s HP IB address is configured at the factory to a value of 20 You must set the output and input functions of your programming language to send the commands to this address You can change the HP IB address from the front panel as described in To change the HP IB address on page 3 5 Remote mode and front panel lockout Whenever the instrument is controlled by a computer the Remote message is displayed on the instrument s screen and the softkey menu is blanked except for the LOCAL softkey This softkey can be pressed by the user to restore front panel control of the instrument You can specify a local lockout mode that prevents the LOCAL softkey from being displayed If the instrument is in local lockout mode all the softkeys may be blanked For example if the instrument is first placed in local lockout mode and then placed in remote mode
150. lues In the List by WL and List by Power displays use the and softkeys to view the reference values wavelength and power values of each laser line before the test was started During the measurement you can change the display mode to Peak WL List by WL List by Power or Avg WL When List by WL or List by Power is selected the signal list is sorted by reference values and not by the current maximum 2 23 Making Measurements Measuring Laser Drift or minimum values To restart the drift measurements press RESET This resets the reference values 2 24 Making Measurements Measuring Signal to Noise Ratios Measuring Signal to Noise Ratios Signal to noise measurements provide a direct indication of system perfor mance Signal to noise measurements are especially important in WDM sys tems because there is a direct relation between signal to noise and bit error rate The HP 86120A displays signal to noise measurements in the third col umn For example the selected signal in the following figure has a signal to noise ratio of 23 4 dB nm Signal to Noise Noise Bandwidth Auto Measurements Indicator Mode 1346 494nm 18 78dRm 17 9dB 1548 084 3 45 19 6k ey UL 1549 698 r r 23 48 OF 15531 31 6 9 23 H WAC 1552 932 1 3 18 7 a M ae Ge ee Understanding how measurements are made is critical During a signal to noise measurement the absolute power of the carrier in dBm
151. m DRIFt PRESet Turns off all the drift states for DIFFerence MAXimum MINimum and REF erence CALCulate3 DRIFt PRESet Preset State unaffected by RST State unaffect ed by SCPI Compliance instrument specific Command Only This command allows the CALC3 DATA query to return the difference between the current measurement and the reference DRIFt REFerence RESet Places the current list of laser lines into the reference list CALCulate3 DRIFt REFerence R Preset State unaffect RST State unaffect ed by ed by ESet SCPI Compliance instrument specific Command Only DRIFt REFerence STATe Turns on and off the drift reference state CALCulate3 DRIFt R FFerence STATe ON OFF 1 O Attribute Summary Description Syntax Attribute Summary Description Programming Commands CALCulate3 Subsystem Preset State off RST State off SCPI Compliance instrument specific When this command is set to on the CALC3 DATA command returns the ref erence laser lines Use the CALC3 DRIF PRES command to turn off all the drift states before turning on the drift reference state Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments
152. mation on non sequential commands refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 Tempo subroutine This subroutine which is only found in example 3 pauses the program for a few seconds while the HP 86120A measures the drift on a laser The argument in the example sets the pause for 10 seconds 3 31 Programming Example Programs Example 1 Measure a DFB laser This program measures the power and wavelength of a DFB laser It first sets the HP 86120A in the single acquisition measurement mode Then it triggers the HP 86120A with the ME ASure command to capture measurement data of the input spectrum Because the data is stored in the instrument s memory it can be queried as needed Refer to the introduction to this section for a description of each subroutine that is contained in this program Programming Example Programs COM Instrument Mwm ASSIGN Mwm TO 720 Set_ese PRINT USING 37A 33A Multi Wavelength Meter Identity is FNIdentity OUTPUT Mwm INIT CONT OFF ON TIMEOUT 7 5 CALL Err_mngmt OUTPUT Mwm MEAS SCAL POW WAV ENTER Mwm Current_wl OUTPUT Mwm FETC SCAL POW ENTER Mwm Current_pwr OFF IMEOUT PRINT USING 20A 4D 3D 3A 19A M2D 2D 4A The wavelength is Current_wl 1 0E 9 nm with a power of T Current pwi dBm END Err_mngmt SUB Err_mngmt CO
153. ment s rear panel connector 1 7 Getting Started Step 3 Connect the Line Power Cable 3 Connect the other end of the line power cord to the power receptacle Various power cables are available to connect the HP 86120A to ac power out lets unique to specific geographic areas The cable appropriate for the area to which the HP 86120A is originally shipped is included with the unit The cable shipped with the instrument also has a right angle connector so that the HP 86120A can be used while sitting on its rear feet You can order additional ac power cables for use in different geographic areas Refer to AC Line Power Cords on page 7 19 1 8 Getting Started Step 4 Connect a Printer Step 4 Connect a Printer The HP 86120A can print hardcopies of measurement results on a printer The output is ASCII text If you don t have a printer continue with Step 5 Turn on the HP 86120A on page 1 10 e Using a standard parallel printer cable connect the printer to the HP 86120A s rear panel PARALLEL PRINTER PORT connector 1 9 Getting Started Step 5 Turn on the HP 86120A Step 5 Turn on the HP 86120A 1 Press the front panel LINE key After approximately 20 seconds the display should look similar to the following figure The front panel LINE switch disconnects the mains circuits from the mains supply after the EMC filters and before other parts of the instrument PEAK HO SIGNAL ao GINES
154. mpany SCP Standard Commands for Program mable Instruments 1995 International Institute of Electrical and Electronics Engineers IEEE Stan dard 488 1 1987 IEEE Standard Digital Interface for Programmable Instrumentation New York NY 1987 International Institute of Electrical and Electronics Engineers IEEE Stan dard 488 2 1987 IEEE Standard Codes Formats Protocols and Com mon commands For Use with ANSITEEE Std 488 1 1987 New York NY 1987 Types of commands The HP 86120A responds to three types of commands e Common commands e Measurement instructions e Subsystem commands All of these commands are documented in Chapter 4 Programming Com mands The common commands are defined by IEEE 488 2 These com mands control some functions that are common to all IEEE 488 2 instruments Common command headers consist of only a single mnemonic preceded by an asterisk The standard SCPI commands are the commands required for com patibility with SCPI Measurement instructions are those commands which are specific to the control of the instrument Measurement instructions are com pound headers consisting of two or more mnemonics Programming Reviewing SCPI Syntax Rules SCPI command are grouped in subsytems In accordance with IEEE 488 2 the instrument s commands are grouped into subsystems Commands in each subsystem perform similar tasks The fol lowing subsystems are provided Measurement Instructions C
155. mpared them to the specifications listed in Chapter 6 Specifications and Regulatory Information Description CAUTION Procedure Servicing Testing Performance Test 3 Polarization Dependence Polarization Dependence is verified using the following devices e 1310 nm and 1550 nm DEB lasers e Optical attenuator e HP 11896A Polarization Controller Do not exceed 18 dBm source power The HP 86120A s input circuitry can be damaged when total input power exceeds 18 dBm Perform the following procedure first using the 1310 nm laser and then repeat the steps using the 1550 nm laser 1 Turn on the lasers and allow them to warm up 2 Set the polarization controller to a scan rate of 5 3 On the HP 86120A press the Preset key 4 Connect the laser s optical output to the polarization controller s optical input 5 Connect the polarization controller s optical output to the HP 86120A being tested 6 Set the polarization controller to autoscan 7 On the HP 86120A press Peak WL Appl s and then DRIFT Press MAX MIN so that both MAX and MIN in the softkey label are highlighted The display shows the total drift since the drift measurement was started 8 Wait five minutes read the peak amplitude drift from the HP 86120A and compare with the specification listed in Chapter 6 Specifications and Regulatory Information 5 23 Description Procedure standard instruments flat contactin
156. ms the equivalent of a front panel PRESET key press S SYSTem VERSion Queries the version of SCPI with which this instrument is compliant S 3 49 Programming Lists of Commands Table 3 7 Programming Commands 5 of 5 Command Description Code Codes S indicates a standard SCPI command indicates an instrument specific command TRIGger Subsystem ABORt Stops the current measurement sequence S INITiate IMMediate Places the instrument into the initiated state and initiates a new S measurement sequence INITiate CONTinuous Sets the instrument for single or continuous measurement S UNIT Subsystem UNIT POWer Sets the power units to watts linear or dBm logarithmic S 3 50 Table 3 8 Keys Versus Commands 1 of 3 Programming Lists of Commands Key Equivalent Command A PWR CALCulate3 DELTa POWer STATe AWL CALCulate3 DELTa WAVelength STATe A WL PWR CALCulate3 DELTa WPOWer STATe Appl s See COH LEN DRIFT and S N AUTO CALCulate3 SNR AUTO ON Avg WL CALCulate2 PWAVerage STATe BAR OFF DISPlay WINDow GRAPhics STATe BAR ON DISPlay WINDow GRAPhics STATe CAL See ELEV PWR OFS STD AIR and VACUUM CM 1 MEASure ARRay POWer WNUMber COH LEN MEASure LENGth COHerence CLENgth Cont INITiate CONTinuous ON DBM UNIT POWer DRIFT CALCulate3 DRIFt STATe ELEV SENSe CORRe
157. n Syntax Attribute Summary Description Programming Commands CALCulate2 Subsystem When the state is on the CALC2 DATA POW query returns the total power and the CALC2 DATA WAV FREQ or WNUM query returns the power weighted average wavelength frequency or wave number values Turning power weighted average mode on while making delta coherence length or signal to noise measurements results in a 221 Settings conflict error WLIMit STATe Limits input wavelength range of the HP 86120A CALCulate2 WLIMit STATe ON OFF 1 0 Non sequential command Preset State on RST State on SCPI Compliance instrument specific When this function is on the HP 86120A has an input range of 1200 nm to 1650 nm When this function is off the instrument displays peaks over the full wavelength range If you are measuring signals between 1200 nm and 1650 nm set this function on to avoid identifying spurious second harmonic peaks Whenever the HP 86120A receives this command it reprocesses the data and performs a new peak search Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrument Refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 for more information 4 35 Programming Commands CALCulate3 Subsystem CALCulate3 Subsystem Use t
158. n 3 39 measure SNR 3 42 external attenuation 2 33 Index F Fabry Perot lasers coherence length 2 29 measuring 2 13 fast fourier transform 4 28 FAST softkey 2 10 2 12 3 10 4 64 FETCh measurement instruction 4 14 fiber optics adapters 7 18 care of v cleaning connections 2 38 connectors covering 1 16 inspecting 2 39 irmware version displayed 1 11 over HP IB 4 7 FL1 line filter assembly 5 42 flatness 6 4 6 7 FNidentity function 3 31 FREQuency programming command 4 18 4 40 4 49 front panel adapters 7 18 labels 6 12 lockout 3 4 parts 5 50 fuse 1 6 drawer 1 6 5 19 extra 1 6 5 19 type 1 6 5 19 H hardcopy See printer HCOPy subsystem 4 58 HELP HEADers programming 4 73 high voltage warning label 5 7 HP 8167A 3 44 HP 8168B 3 44 HP 8168C 3 44 HP BASIC 3 2 3 30 HP offices 7 20 HP IB address 3 4 address changing from front panel 3 5 address default 3 4 softkey 3 5 command I IDN 3 31 4 7 IEC Publication 1010 vi IEEE 488 2 standard 3 23 IMMediate programming command 4 58 4 79 index matching compounds 2 38 infinity representation 3 26 init ignored 7 16 initializing the instrument 3 4 input connector 2 38 power definition of 6 4 INPUT connector v inspecting cables 2 39 instrument 1 4 installing 1 2 instrument addressing over HP IB 3 4 cover removing 5 31 default state 2 2 front view 6 12 preset conditions 4 75 7 3 rear v
159. n continue 2 22 Making Measurements Measuring Laser Drift To measure drift w A Press the front panel Preset key Press Peak WL List by WL or List by Power to select the display style for observing drift Press Appl s and then DRIFT Pressing DRIFT sets the current laser line values as the reference from which to compare all drift Press MAX MIN for the desired type of drift measurement as described in the following paragraphs Display shows the current values of laser lines relative to the wavelength and power values measured when the test was begun or the RESET softkey was pressed Display shows absolute maximum values since the drift measurement was started This measurement gives the longest wavelength and greatest power measured The laser line of interest may have since drifted to a lesser value Note that the maximum wavelength and maximum power may not have occurred simultaneously Display shows absolute minimum values since the drift measurement was started This measurement gives the shortest wavelength and smallest power measured The laser line of interest may have since drifted to a greater value Note that the minimum wavelength and minimum power may not have occurred simultaneously Display shows the total drift from the reference since the 5 drift measurement was started Values represent the minimum wavelength and power drift values subtracted from the maximum drift va
160. n signal to noise ratio on Cmd_ope CALC3 SNR STAT ON Err_mngmt CALC3 SNR STAT ON Set first wavelength as noise reference Cmd_opc CALC3 SNR REF WAV MIN Err_mngmt CALC3 SNR REF WAV MIN Query number of data points OUTPUT ENTER ALLOCATE Snr_pwr 1 Nb_pt Mwm CALC3 POIN wm USING K Nb_pt Query OUTPUT ENTER signal to noise values Mwm CALC3 DATA POW wm Snr_pwr OFF TIMEOUT 3 42 Programming Example Programs FOR I 1 TO Nb_pt PRINT USING 7A 2D 17A M4D 3D 25A S2D 2D 22A 2D 2D 3A Line I wavelength is Current_wl I 1 0E 9 nm absolute level is Current_pwr I dBm with a SNR of Snr_pwr I dB EXT I STOP Error_msg PRINT The program is aborted due to ERRMS END Err_mngmt SUB Err_mngmt OPTIONAL Cmd_msg COM Instrument Mwmt DIM Err_msg 255 INTEGER Cme CLEAR Mwm REPEAT OUTPUT Mwm ESR ENTER Mwm Cme OUTPUT Mwm SYST ERR ENTER Mwm Err_msg IF NPAR gt O AND NOT POS Err_msg 0 THEN PRINT This command Cmd_msg makes the following error IF NOT POS Err_msg 0 THEN PRINT Err_msg UNTIL NOT BIT Cme 2 AND NOT BIT Cme 4 AND NOT BIT Cme 5 AND POS Err_msg 0 Subend SUBEND UHH Set_ese SUB Set_es COM Instrument
161. nals For example a laser that is amplitude modulated in the audio frequency range can cause spurious wavelengths to be displayed below and above the correct wavelength The power of these spurious wavelengths is below that of the correct wavelength These spurious signals can be eliminated by decreasing Peak threshold from its Preset value Power dBm Making Measurements Defining Laser Line Peaks Peak excursion The peak excursion defines the rise and fall in amplitude that must take place in order for a laser line to be recognized The rise and fall can be out of the noise or in the case of two closely spaced signals out of the filter skirts of the adjacent signal The peak excursion s default value is 15 dB Any laser line that rises by 15 dB and then falls by 15 dB passes the rule You can set the peak excursion value from 1 to 30 dB Examples of valid and invalid signals In the following figure three laser lines are identified responses and Response is not identified because it is below the peak threshold The por tion of each signal that is within the peak excursion limits is shown in bold lines Because of the peak excursion rule responses and are identified as one laser line the minimum point between and does not drop to the peak excursion limit This response has the highest power shown which is peak Whenever the peak threshold limit or peak excursion value is changed the new limits
162. nction Gf known Quantity needed Parts can be ordered by addressing the order to the nearest Hewlett Packard office Customers within the USA can also use either the direct mail order sys tem or the direct phone order system described below The direct phone order system has a toll free phone number available 5 43 Servicing Replaceable Parts Direct mail order system Within the USA Hewlett Packard can supply parts through a direct mail order system Advantages of using the system are as follows e Direct ordering and shipment from Hewlett Packard e No maximum or minimum on any mail order There is a minimum order amount for parts ordered through a local HP office when the orders require billing and invoicing e Prepaid transportation There is a small handling charge for each order e No invoices To provide these advantages a check or money order must accompany each order Mail order forms and specific ordering information are available through your local HP office Direct phone order system The toll free phone number 800 227 8164 is available Monday through Fri day 6 am to 5 pm Pacific time Regular orders have a 4 day delivery time Servicing Replaceable Parts 5 45 Servicing Replaceable Parts Table 5 7 Major Assemblies Reference HP Part Description Designator Number Al 86120 60010 Optical Block Assembly Includes A1A1 A1A2 and A1A3 86120 69010 Opt
163. nd The MEASure command is one of four measurement instructions MEASure READ FETCh and CONFigure The syntax for measurement instructions is documented in Measurement Instructions on page 4 14 Each measurement instruction has an argument that controls the measure ment update rate This is equivalent to using the NORMAL and FAST softkeys MEASure command MEASure configures the HP 86120A captures new data and queries the data all in one step For example to measure the longest wavelength send the fol lowing command MEASure SCALar POWer WAVelength MAX Table 3 2 The Different Forms of MEASure Desired Use this Display Format Measurement Data MEASure Query Power W dBm MEASure ARRay POWer List by Power MEASure SCALar POWer single wavelength mode Frequency Hz MEASure ARRay POWer FREQuency List by WL frequency MEASure SCALar POWer FREQuency single wavelength mode Wavelength m MEASure ARRay POWer WAVelength List by WL MEASure SCALar POWer WAVelength single wavelength mode Wavenumber m7 MEASure ARRay POWer WNUMber List by WL MEASure SCALar POWer WNUMber single wavelength mode Coherence Length m MEASure LENGth COHerence coherence length 3 10 Programming Making Measurements Specifying SCALar places the display in the single wavelength format and returns a single value to the computer Specifying ARRay pl
164. nd The instrument returns a string which is the last instrument function sent by a CONFigure command or MEASure query The returned string is in the short command form Use caution when using this query because if any instrument settings were changed since the last CONFig ure command or MEASure query these changes may not be included in the returned string For example if the last CONFigure command was CONFigure SCALar POWer WAVelength 1300NM MAX a CONFigure query would return a string that is similar to the following line POW WAV 1 300000e 6 0 01 The 1300NM and resolution values track the actual instrument settings and input signals Notice that the quotation marks are part of the returned string Return single or multiple measurement values You can specify whether FETCh READ or MEASure returns a single value SCALar or multiple values ARRay The example the following command specifies SCALar data which returns a single value MEASure SCALar POWer WAVelength MAX 3 12 Programming Making Measurements ARRay and the SCPI standard According to the SCPI command reference ARRay command causes an instrument to take multiple measurements A lt size gt parameter indicates the number of measure ments to take However the HP 86120As ARRay command refers to the measurements performed for one measurement sweep this results in an array of measured signals Because the lt size gt parameter does not apply an
165. nformation w1 W12 Top View rpcable 5 11 W3 W2 w1 W4 W11 W10 Bottom View DNA W13 0509259 589 a 09909 086 896262 0 0 S W5 W6 W13 W7 w8 w9 Servicing Electrostatic Discharge Information Electrostatic Discharge Information Electrostatic discharge ESD can damage or destroy electronic components All work on electronic assemblies should be performed at a static safe work station The following figure shows an example of a static safe work station using two types of ESD protection e Conductive table mat and wrist strap combination e Conductive floor mat and heel strap combination Building Ground 1 Meg Ohm Resistor Building Ground Both types when used together provide a significant level of ESD protection Of the two only the table mat and wrist strap combination provides adequate ESD protection when used alone 5 12 WARNING Servicing Electrostatic Discharge Information To ensure user safety the static safe accessories must provide at least 1 MQ of isolation from ground Refer to Table 5 5 on page 5 13 for information
166. ng SCPI Syntax Rules Sending common commands If a subsystem has been selected and a common command is received by the instrument the instrument remains in the selected subsystem For example if the program message DISPLAY MARK MAX LEFT CLS DISP MARK MAX RIGH is received by the instrument the Display subsystem remains selected If some other type of command is received within a program message you must reenter the original subsystem after the command Adding parameters to a command Many commands have parameters that specify an option Use a space charac ter to separate the parameter from the command as shown in the following line OUTPUT 720 INIT CONT ON Separate multiple parameters with a comma Spaces can be added around the commas to improve readability OUTPUT 720 MEAS SCAL POW FREQ 1300 MAX White space White space is defined to be one or more characters from the ASCII set of 0 through 32 decimal excluding 10 NL White space is usually optional and can be used to increase the readability of a program Numbers All numbers are expected to be strings of ASCII characters Thus when send ing the number 9 you would send a byte representing the ASCII code for the character 9 which is 57 A three digit number like 102 would take up three bytes ASCII codes 49 48 and 50 This is taken care of automatically when you include the entire instruction in a string Several represe
167. ng the sources to within the absolute wavelength accuracy specification Description CAUTION Procedure Servicing Testing Performance Test 2 Sensitivity Sensitivity is verified using the following devices e Optical power meter e Optical attenuator e 1310 nm and 1550 nm lasers gt 0 dBm output power Do not exceed 18 dBm source power The HP 86120A s input circuitry can be damaged when total input power exceeds 18 dBm Perform the following procedure first using the 1310 nm laser and then repeat the steps using the 1550 nm laser 1 Connect the laser s output to the optical attenuator s input 2 Connect the optical attenuator s output to the optical power meter 3 Adjust the attenuator for a reading of 0 dBm on the power meter Record the attenuator s setting Attenuation at 0 dBm 4 Adjust the attenuator for a reading of 35 dBm on the power meter Record the attenuator s setting Attenuation at 35 dBm 5 Disconnect the fiber optic cable at the power meter s input and connect the cable to the HP 86120A being tested 6 Reset the optical attenuator to the setting recorded in Step 3 7 Read the power and wavelength measured on the HP 86120A and compared them to the specifications listed in Chapter 6 Specifications and Regulatory Information 8 Reset the optical attenuator to the setting recorded in Step 4 9 Read the power and wavelength measured on the HP 86120A and co
168. nstrument Cover Parts Item ee Oty Description 1 0515 0380 2 Screw TORX T15 Pan Head M4 x 0 7 10 mm long 2 0515 1227 6 Screw TORX T10 Flat Head M3 x 0 5 6 mm long 3 01650 47701 2 Molded feet 4 1460 1345 2 Spring leg 5 08590 40005 2 Plastic spacer for rear foot 6 5041 8929 2 Foot rear 7 86120 00007 1 Instrument Cover 8 0340 1505 1 Insulator 86120 60028 1 Handle Assembly not shown in drawing 5 60 Servicing Replaceable Parts rpinscvi 5 61 Servicing Replaceable Parts Specifications and Regulatory Information Contents Specifications and Regulatory Information Specifications and Regulatory Information Specifications and Regulatory Information This chapter lists specification and characteristics of the instrument The dis tinction between these terms is described as follows e Specifications describe warranted performance over the temperature range 0 C to 55 C and relative humidity lt 95 unless otherwise noted All specifications apply after the instrument s temperature has been stabilized after 15 minutes of continuous operation e Characteristics provide useful information by giving functional but non warranted performance parameters Characteristics are printed in ital Cs Calibration Cycle This instrument requires periodic verification of performance The instrument should have a complete verification of specification
169. ntations of a number are possible For example the following numbers are all equal 28 0 282 280E 1 28000m 0 028K 28E 3K 3 26 Programming Reviewing SCPI Syntax Rules If ameasurement cannot be made no response is given and an error is placed into the error queue For example RST FETCh POW will timeout the controller and place a Data stale or corrupt error ino the error queue Table 3 6 Suffix Multipliers Multiplier Mnemonic 1E18 EX 1E15 PE 1E12 T 1E9 G 1E6 MA 1E3 K 1E 3 M 1E 6 U 1E 9 N 1E 12 P 1E 15 F 1E 18 A Program message terminator The string of instructions sent to the instrument are executed after the instruction terminator is received The terminator may be either a new line NL character the End Or Identify OTD line asserted or a combination of the two All three ways are equivalent Asserting the EOI sets the EOI control line low on the last byte of the data message The NL character is an ASCII linefeed decimal 10 The NL terminator has the same function as an EOS End Of String and EOT End Of Text terminator 3 27 Programming Reviewing SCPI Syntax Rules Querying data Data is requested from the instrument using a query Queries can be used to find out how the instrument is currently configured They are also used to get results of measurements made by the instrument with the query actually acti vating the measurement Strin
170. nterpret 7 5 Reference Menu Maps Appl s Menu Appl s S N DRIFT COH LEN RETURN A AUTO 4 t USER j PEAK USER WL gt WL REF CANCEL RETURN RETURN 4 v MAX MIN RESET EXIT EXIT mappls 7 6 Reference Menu Maps Display Avg WL Menu There is no menu associated with this key Measurement Cont Menu There is no menu associated with this key Display List by Power Menu Power 4 f PEAK SELECT mlistpwr 7 7 Reference Menu Maps Display List by WL Menu WL 4 y PEAK SELECT mlistwl Delta On Menu AWL APWR AWL PWR SELECT RESET RETURN EXIT 7 8 Reference Menu Maps Delta Off Menu Off Display Peak WL and System Preset Menus Peak WL PREV WL NEXT WL PEAK PREV PK NEXT PK mpreset Measurement Single Menu There is no menu associated with this key 7 9 Reference Menu Maps System Print Menu CONT ABORT moprint Reference Menu Maps System Setup Menu UPDATE NORMAL UNITS FAST CAL NM MORE cM RETURN THZ RETURN RETURN RETURN DBM MW VACUUM Uwy STD AIR ELEV PWR OFS RETURN LIM ON LIM OFF RETURN RETURN HP IB THRSHLD A WLLI EON R CANCEL PWR BAR RETURN RETURN BAR OFF RETURN RETURN msetup 7 11 Reference Error Messages Error Messages
171. ocumentation contains information and warnings which must be followed by the user to ensure safe operation and to maintain the product in a safe condition If this instrument is not used as specified the protection provided by the equipment could be impaired This instrument 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 personnel To prevent electrical shock do not remove covers Printing History Printing History HP Part Number Edition Date 86120 90001 First March 1996 Typographical Conventions The following conventions are used in this book Formatting Information key type Keys or text located on the keyboard or instrument softkey type Key names that are displayed on the instrument s screen display type Words or characters displayed on the computer s screen or instrument s display user type Words or characters that you type or enter emphasis type Words or characters that emphasize some point or that are used as place holders for text that you type Limitation of Warranty Exclusive Remedies Warranty Warranty This Hewlett Packard instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment During the warranty period Hewlett Packard Company will at its option either repair or replace products whi
172. ommands Measurement Instructions MEASure ARRay SCALar POWer WAVelength Returns wavelength values POWer WAVelength lt expected_value gt lt resolution gt Used With lt expected_value gt lt resolution gt SCALar optional optional ARRay ignored optional a Although ignored this argument must be present if the resolution argument is specified When used with a SCALar command a single value is returned The display is placed in the single wavelength mode and the marker is placed on the signal having a wavelength that is closest to the lt expected_value gt parameter Default units for lt expected_value gt parameter is in meters When used with an ARRay command an array of wavelengths is returned The display is placed in the list by wavelength mode The lt vesolution gt parameter sets the resolution of the measurement It is a unitless number whose value will be limited to either 0 01 or 0 001 whichever is closer Returned values are in meters Displayed units are nanometers Power units are not affected CONFigure command When this function is used with the CONFigure command the query question mark char acter must not be included in the string However the FETCh READ and MEASure command are queries and require the question mark Refer to the examples for this com mand MAXimum The highest wavelength signal MINimum The lowest wavelength signal D
173. on are small enough to fit into adapters Although foam swabs can leave filmy deposits these deposits are very thin and the risk of other contamination buildup on the inside of adapters great ly outweighs the risk of contamination by foam swabs 2 Clean the adapter with the foam swab 3 Dry the inside of the adapter with a clean dry foam swab 4 Blow through the adapter using filtered dry compressed air Nitrogen gas or compressed dust remover can also be used Do not shake tip or invert compressed air canisters because this releases particles in the can into the air Refer to instructions provided on the compressed air canister To test insertion loss and return loss To test insertion loss use an appropriate lightwave source and a compatible lightwave receiver to test insertion loss Examples of test equipment configu rations include the following equipment e HP 71450B 51B 52B optical spectrum analyzers with Option 002 built in 2 41 Making Measurements Cleaning Connections for Accurate Measurements white light source HP 8702 or HP 8703 lightwave component analyzer system HP 83420 lightwave test set with an HP 8510 network analyzer HP 8153 lightwave multimeter with a source and power sensor module To test return loss use an appropriate lightwave source a lightwave receiver and lightwave coupler to test return loss Examples of test equipment configu rations include the following equipment HP 8703 l
174. on the instrument or prevent it from shifting in the carton They may also cause instrument damage by generating static electricity 3 Pack the instrument in the original shipping containers Original materials are available through any Hewlett Packard office Or use the following guidelines Wrap the instrument in antistatic plastic to reduce the possibility of damage caused by electrostatic discharge For instruments weighing less than 54 kg 120 Ib use a double walled 1 16 Getting Started Returning the Instrument for Service corrugated cardboard carton of 159 kg 850 Ib test strength e The carton must be large enough to allow 3 to 4 inches on all sides of the instrument for packing material and strong enough to accommodate the weight of the instrument e Surround the equipment with 3 to 4 inches of packing material to pro tect the instrument and prevent it from moving in the carton If packing foam is not available the best alternative is S D 240 Air Cap from Sealed Air Corporation Commerce California 90001 Air Cap looks like a plastic sheet filled with air bubbles Use the pink antistatic Air Cap to reduce static electricity Wrapping the instrument several times in this material will protect the instrument and prevent it from moving in the carton 4 Seal the carton with strong nylon adhesive tape 5 Mark the carton FRAGILE HANDLE WITH CARE 6 Retain copies of all shipping papers Getting
175. pairs damaged cables and compromised measurements Before you connect any fiber optic cable to the HP 86120A refer to Cleaning Connec tions for Accurate Measurements on page 2 38 1 3 Getting Started Step 1 Inspect the Shipment Step 1 Inspect the Shipment I Verify that all system components ordered have arrived by comparing the shipping forms to the original purchase order Inspect all shipping containers If your shipment is damaged or incomplete save the packing materials and notify both the shipping carrier and the nearest Hewlett Packard sales and Service office HP will arrange for repair or replacement of damaged or incomplete shipments without waiting for a settlement from the transportation company Notify the HP customer engineer of any problems Make sure that the serial number and options listed on the instrument s rear panel label match the serial number and options listed on the shipping document The following figure is an example of the rear panel serial number label Hewlett Packard 86120A SN 001 Lightwave Operation Santa Rosa CA 95403 Made in USA of domestic And foreign components 1 4 Getting Started Step 1 Inspect the Shipment Table 1 1 Options and Accessories Available for the HP 86120A Item Quantity HP Part Number Option 010 Delete FC PC connector Option 022 Replace flat physical contact int
176. plete lt imteger gt OUT PUT 720 TST EN ER 720 Result PRINT Result 4 12 Syntax Description Programming Commands Common Commands WAI The WAI command prevents the instrument from executing any further com mands until the current command has finished executing WAI All pending operations are completed during the wait period This command cannot be issued as a query 4 13 Programming Commands Measurement Instructions Measurement Instructions Use the measurement instructions documented in this section to perform measurements and return the desired results to the computer Four basic measurement instructions are used CONFigure FETCh READ and MEA Sure Because the command trees for each of these four basic measurement instructions are identical only the MEASure tree is documented To perform a measurement append to the measurement instruction a POWer or LENGth function The POWer functions select power frequency wave length or wave number measurements Use the LENGth functions to config ure the instrument to measure coherence length The instrument measures the coherence length in the time domain by rectifying and low pass filtering the interferogram The resulting waveform is then curve fit into a decaying exponential Refer to Measuring Coherence Length on page 2 29 When the SCALar command is used data for a single measurement value is returned W
177. program measures the line separations on a Fabry Perot laser It mea sures separation delta between power and wavelength of each line using commands from the CALCulate3 subsystem Refer to the introduction to this section for a description of each subroutine that is contained in this program COM Instrument Mwm ASSIGN Mwm TO 720 DIM Key 1 ON ERROR GOTO Error_msg Set_ese PRINT USING 37A 33A Multi Wavelength Meter Identity is FNIdentity ON TIMEOUT 7 5 CALL Err_mngmt Cmd_opc RST Change to list by wavelength display Cmd_opc CONF ARR POW WAV Trigger and wait for one measurement Cmd_opc INIT Cmd_opc WAI Turn on delta mode Cmd_opc CALC3 DELT WPOW STAT ON Set first wavelength as reference Cmd_opc CALC3 DELT REF WAV MIN Query number of data points OUTPUT Mwm CALC3 POIN ENTER Mwm USING K Nb_pt ALLOCATE Delta_wl 1 Nb_pt ALLOCATE Delta_pwr 1 Nb_pt Query wavelengths and powers OUTPUT Mwm CALC3 DATA WAV ENTER Mwm Delta_wl UTPUT Mwm CALC3 DATA POW ENTER Mwm Delta_pwr 3 39 Programming Examp OFF T FOR I PR I PR CO NEXT PRINT wavel Absol Pp STOF PR END Err m CO DI wave a ec I 1 Delta_pwr I 1 Del le Programs iE EOUT 1 TO Nb_pt 1 INT
178. ptical path delay The time domain data is sampled at uniform optical path delay increments of half the reference laser wavelength or 0 316495 microns When NORMAL measure ment update is selected the first data value is sampled at 20 74 mm optical path delay and the last value is sampled at 20 74 mm optical path delay When FAST measurement update is selected the first data value is sampled at Query Response Programming Commands SENSe Subsystem 2 59 mm optical path delay and the last value is sampled at 2 59 mm optical path delay The data value that corresponds to zero optical path delay is approximately but not exactly located in the center of the time domain data If your program is aborted or interrupted after sending this query the HP 86120A continues to process the data but does not place it in the output buffer Because of the amount of data processed the instrument will not respond to any new commands in its input buffer for 30 or 40 seconds The following string shows an example of the first few measurements returned by this query 1 51367200E 000 1 51855500E 000 1 49902300E 000 1 47949200 000 4 1 50488300E 000 1 53320300E 000 1 50097700E 000 1 47 65600E 000 1 50293000E 000 1 50781300E 000 1 51171900E 000 1 48242200E 000 1 50097700E 000 1 51855500E 000 1 5068360 E 000 1 48632800E 000 1 50488300E 000 o NE Notic
179. rom all voltage sources while it is being opened The power cord is connected to internal capacitors that may remain live for five seconds after disconnecting the plug from its power supply 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 5 2 Servicing Servicing WARNING For continued protection against fire hazard replace line fuse only with same type and ratings type T 6 3A 250V for 100 240V operation The use of other fuses or materials is prohibited Contents General Information 5 4 Electrostatic Discharge Information 5 12 Reducing ESD Damage 5 13 Troubleshooting 5 14 If a general problem occurs 5 16 If the display is blank 5 16 If random symbols are displayed 5 16 If the front panel keys don t work 5 16 If the fan doesn t run 5 17 To check the power supply voltages 5 17 To check the Al Optical Block Assembly 5 18 To check the line power fuse 5 19 Testing Performance 5 20 Test 1 Absolute Wavelength Accuracy 5 21 Test 2 Sensitivity 5 22 Test 3 Polarization Dependence 5 23 Test 4 Optical Input Return Loss 5 24 Test 5 Amplitude Accuracy and Linearity 5 26 Replacing Instrument Assemblies 5 30
180. ruption of the protective conductor inside or outside of the instrument is likely to make the instrument dangerous Intentional interruption is prohibited This product has autoranging line voltage input Be sure the supply voltage is within the specified range When installing the product in a cabinet the convection into and out of the product must not be restricted The ambient temperature outside the cabinet must be less than the maximum operating temperature of the product by 4 C for every 100 watts dissipated in the cabinet If the total power dissipated in the cabinet is greater than 800 watts then forced convection must be used This product is designed for use in INSTALLATION CATEGORY II and POLLUTION DEGREE 2 per IEC 1010 and 664 respectively 1 2 Contents Getting Started Getting Started Step 1 Inspect the Shipment 1 4 Step 2 Check the Fuse 1 6 Step 3 Connect the Line Power Cable 1 7 Step 4 Connect a Printer 1 9 Step 5 Turn on the HP 86120A 1 10 Step 6 Enter Your Elevation 1 12 Step 7 Select Medium for Wavelength Values 1 13 Step 8 Turn Off Wavelength Limiting 1 14 Returning the Instrument for Service 1 15 Measurement accuracy it s up to you Fiber optic connectors are easily damaged when connected to dirty or damaged cables and accessories The HP 86120A s front panel INPUT connector is no exception When you use improper cleaning and handling techniques you risk expensive instrument re
181. ry Road Paramus NJ 07653 201 586 5400 Texas Hewlett Packard Company 930 East Campbell Road Richardson TX 75081 214 231 6101 EUROPEAN FIELD OPERATIONS Headquarters Hewlett Packard S A 150 Route du Nant d Avril 1217 Meyrin 2 Geneva Switzerland 41 22 780 8111 France Hewlett Packard France 1 Avenue Du Canada Zone D Activite De Courtaboeuf F 91947 Les Ulis Cedex France 33 1 69 82 60 60 Germany Hewlett Packard GmbH Hewlett Packard Strasse 61352 Bad Homburg Germany 49 6172 16 0 Great Britain Hewlett Packard Ltd Eskdale Road Winnersh Triangle Wokingham Berkshire RG11 5DZ 7 20 Hewlett Packard Sales and Service Offices 2 of 2 Reference Hewlett Packard Sales and Service Offices INTERCON FIELD OPERATIONS Headquarters Hewlett Packard Company 3495 Deer Creek Rd Palo Alto California 94304 1316 415 857 5027 Australia Hewlett Packard Australia Ltd 31 41 Joseph Street Blackburn Victoria 3130 61 3 895 2895 Canada Hewlett Packard Ltd 17500 South Service Road Trans Canada Highway Kirkland Quebec H9J 2X8 Canada 514 697 4232 China China Hewlett Packard Company 38 Bei San Huan X1 Road Shuang Yu Shu Hai Dian District Beijing China 86 1 256 6888 Japan Yokogawa Hewlett Packard Ltd 1 27 15 Yabe Sagamihara Kanagawa 229 Japan 81 427 59 1311 Singapore Hewlett Packard Singapore Ltd Pte Ltd Alexandra
182. s These include the following procedures To remove the instrument cover 5 31 To replace the Al Optical Block Assembly 5 32 To replace the A3 High Voltage Power Supply Assembly 5 37 To replace a cable clip 5 41 To replace line filter assembly FL1 5 42 CAUTION CAUTION Servicing Replacing Instrument Assemblies To remove the instrument cover Disconnect the power cord from the instrument Use a T 15 TORX driver to remove the two screws that attach the handle to the instrument Locate the two bumper feet attached to the rear panel Use a 4 mm hex key to remove the four bolts that secure the two bumper feet to the rear panel Although the bumper feet are no longer attached to the instrument s frame they are still attached to the instrument s cover Beneath the cover located in the vicinity of the handle attachment screws are two finger springs that reduce electro magnetic interference EMI These springs can be damaged Carefully perform the following steps to remove the cover without causing damage 5 Use one hand to apply pressure to the opposite side of the cover from the side with the handle Simultaneously pull on the instrument foot that is located on the handle side This action relieves strain on the springs while removing the cover Slide the instrument cover assembly toward the rear of the instrument and remove it from the instrument When replacing the cover be careful to protect the instr
183. s at least once every year Definition of Terms 6 3 Specifications 6 6 Regulatory Information 6 10 6 2 Wavelength Specifications and Regulatory Information Definition of Terms Definition of Terms Range refers to the allowable wavelength range of the optical input signal Absolute accuracy indicates the maximum wavelength error over the allowed environmental conditions The wavelength accuracy is based on fundamental physical constants which are absolute standards not requiring traceability to artifacts kept at national standards laboratories Four He Ne gas lasers are used First there is an internal 632 991 nm vacuum 473 6127 THz reference laser To verify absolute wavelength accuracy three external lasers are mea sured during manufacturing with these wavelengths 730 685 nm or 410 2896 THz 1152 591 nm or 260 1032 THz 1523 488 nm or 196 7804 THz Differential Accuracy indicates the maximum wavelength error in measuring the wavelength difference between two signals that are simultaneously present Minimum Resolvable Separation indicates the minimum wavelength separa tion of two laser lines required to measure each wavelength simultaneously Two laser lines closer in wavelength than the minimum resolvable separation are not resolved and one average wavelength is displayed Display Resolution indicates the minimum incremental change in displayed wavelength 1 Obarski G E 1990 Wavelength Measurement
184. s specified When used with a SCALar command a single value is returned The display is placed in the single wavelength mode and the marker is placed on the signal having a wave number that is closest to the lt expected_value gt parameter Default units for lt expected_value gt parameter is in m When used with an ARRay command an array of wave number is returned The display is placed in the list by wavelength mode The lt resolution gt parameter sets the resolution of the measurement It is a unitless number whose value will be limited to either 0 01 or 0 001 whichever is closer Returned values are in inverse meters Displayed units are inverse centime ters Power units are not affected CONFigure command When this function is used with the CONFigure command the query question mark char acter must not be included in the string However the FETCh READ and MEASure command are queries and require the question mark Refer to the examples for this com mand MAXimum The laser line having the largest wave number MINimum The laser line having the smallest wave number DEFault The current marker position 4 22 Programming Commands Measurement Instructions lt resolution gt MAXimum 0 01 resolution fast update Constants MINimum 0 001 resolution normal DEFault Current resolution Examples CONF ARR POW WNUM DEF MAX FETC ARR POW WNUM DEF MIN READ ARR POW W
185. s user entered reference frequency 4 48 Attribute Summary Description Syntax Attribute Summary Description Programming Commands CALCulate3 Subsystem Preset State on RST State on SCPI Compliance instrument specific The command argument allows you to select either an internally generated or a user entered frequency reference for measuring the noise This value can either be internally generated or a user entered frequency To enter a value to use as the reference use the SNR REFerence FREQuency SNR REFerence WAVelength and SNR REFerence WNUMber commands Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrument Refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 for more information SNR REFerence FREQuency Enters a frequency that can be used for the noise measurement reference in signal to noise calculations CALCulate3 SNR REFerence FREQuency lt real gt MINimum MAXimum lt real gt is a frequency value that is within the following limits Constant Description MINimum 428 2749 THz MAXimum 181 6924 THz Preset State unaffected by RST State 193 4144 THz 1550 0 nm in a vacuum SCPI Compliance instrument specific After entering this value use the SNR AUTO command to configure the instrument to use this value
186. sages 3 of 3 Reference Error Messages Error Number Desription 310 System error 321 Out of memory 350 Too many errors 400 Query error 410 Query INTERRUPTED 420 Query UNTERMINATED 430 Query DEADLOCKED 440 Query UNTERMINATED after indef resp Query was unterminated after an indefinite response 7 17 Reference Front Panel Fiber Optic Adapters Front Panel Fiber Optic Adapters The FC PC adapter is the standard adapter supplied with the instrument FC PC Biconic D4 HP 81000FI HP 81000WI HP 81000GI Diamond HMS 10 DIN sc ST HP 81000Al HP 81000SI HP 81000KI HP 81000VI kent4s Reference AC Line Power Cords AC Line Power Cords CABLE PLUG LENGTH FOR USE DESCRIPTION cM IN COUNTRY INCHES CABLE HP PART NUMBER 8120 1351 Straight BS1363A 229 90 Mint Gray Great Britain 8120 1703 90 229 90 Mint Gray Cyprus Nigeria Singapore Zimbabwe 8120 1369 Straight NZSS198 201 79 Argentina ASC112 Australia 8120 0696 90 221 87 New Zealand Mainland China 8120 1689 Straight CEE7 Y11 201 79 Mint Gray East and West 8120 1692 90 201 79 Mint Gray Europe Central African Republic United Arab Republic unpolarized in many nations 8120 1348 Straight NEMA5 15P 203 80 Black United States 8120 1538 90 20
187. sition is defined to occur whenever the selected bit changes states from a 0 to a 1 You can enter any value from 0 to 65535 When queried the largest value that can be returned is 32767 This is because the most significant register bit cannot be set true OUTPUT 720 STATUS OPER PTRansition 16 4 69 Programming Commands STATus Subsystem PRESet Presets the enable registers and the PTRansition and NTRansition filters Syntax STATus PRESet Attribute Summary Preset State none RST State none SCPI Compliance standard Command Only Description The PRESet command is defined by SCPI to affect the enable register If you want to clear all event registers and queues use the CLS command Table 4 7 Preset Values Status Node Preset Value Operation enable register 0 Questionable enable register 0 PTRansition filters 32767 NTRansition filters 0 Example OUTPUT 720 STATUS PRESET 4 70 Programming Commands SYSTem Subsystem SYSTem Subsystem The commands in this subsystem have the following command hierarchy SYSTem ERRor HELP HEADers PRESet VERSion 4 71 Syntax Attribute Summary Description Query Response Example Programming Commands SYSTem Subsystem ERRor Queries an error from the error queue SYSTem ERRor Preset State none RST State none SCPI Compliance standard Query Only The HP 86120A has a 30
188. speed 1 Press the Setup key 2 Press the UPDATE softkey 3 Select either NORMAL or FAST Making Measurements Defining Laser Line Peaks Defining Laser Line Peaks The HP 86120A uses two rules to identify valid laser line peaks Understand ing these rules is essential to getting the most from your measurements For example these rules allow you to hide AM modulation sidebands or locate laser lines with small amplitudes In order to identify a laser line the laser line must meet both of the following rules e Power must be greater than the power established by the peak threshold limit e Power must rise and then fall by at least the peak excursion value In addition the input wavelength range can be limited as described in this sec tion Peak threshold limit The peak threshold limit is set by subtracting the peak threshold value from the power of the largest laser line So if the largest laser line is 2 dBm and the peak threshold value is 10 dB the peak threshold limit is 8 dBm 8 dBm 2 dBm 10 dB You can set the peak threshold value between 0 to 40 dB The peak threshold s default value is 10 dB This ensures that any modulated signals being measured are not confused with their AM sidebands For unmod ulated lasers or Fabry Perot lasers it may be desirable to increase this threshold to look for responses that are more than 10 dB from the peak Peak threshold can be used to suppress spurious sig
189. ssembly A3 High Voltage Power Supply Assembly A4 Digital Signal Processing Board Assembly A5 Main Board Assembly A6 Front Panel Assembly includes A6A2 Does not include A6A1 A6A1 Display Assembly includes printed circuit board A6A2 Flexible keypads B1 Fan Assembly FL1 Line Module Filter Part of W12 5 8 Servicing General Information A3 A6A2 Top View G OGo000 l A6 a See A2 D00 a A6A1 See A1A3 A1A1 A1A2 Bottom View AS 3 FL1 TF D G H o o o B1 o 9 A4 Qo Q C rpmajoi 5 9 Servicing General Information Table 5 4 Cable Assemblies Reference Desiqnator Description w1 Input Fiber Optic Cable W2 Front Panel Ribbon Cable W3 Display Power Cable W4 SMB Cable 260 mm long w5 SMB Cable 310 mm long W6 Detector Bias Cable W7 Main Bus Cable W8 Part of B1 wg Digital Signal Processing Ribbon Cable W10 Control Cable for A1 Assembly W11 Control Cable for A1 Assembly W12 Line Switch Cable includes FL1 W13 Power Harness Cable 5 10 Servicing General I
190. stem DELTa POWer STATe Turns the delta power measurement mode on and off CALCulate3 DELTa POWer STATe ON OFF 1 0 Preset State off RST State off SCPI Compliance instrument specific When this state is on the power of the reference laser line is subtracted from the power values of all laser lines except the reference The power data returned by the CALC3 DATA query is the array of laser line power levels normalized to the power level of the reference laser line The power of the reference laser line is returned as an absolute power unnormal ized The frequency data returned is the array of absolute frequency values Note Only one STATe command can be turned on at any one time Attempting to turn more than one state on at a time results in a 221 Settings Conflict error Refer to CALCulate3 Subsystem on page 4 36 for additional information on selecting measure ments DELTa PRESet Turns off all delta measurement states CALCulate3 DELTa PRESet Preset State not affected RST State not affected SCPI Compliance instrument specific Command Only 4 39 Syntax Attribute Summary Description Syntax Attribute Summary Programming Commands CALCulate3 Subsystem DELTa REFerence FREQuency Selects the reference laser line for DELTa calculations CALCulate3 DELTa REFerence FREQuency lt real gt MINimum MAXimum
191. t Refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 for more information Programming Commands CALCulate1 Subsystem Query Response For normal update 34123 For fast update 4268 4 29 Programming Commands CALCulate2 Subsystem CALCulate2 Subsystem Use the CALCulate2 commands to query corrected values frequency spec trum data The commands in this subsystem have the following command hierarchy CALCulate2 DATA PEXCursion POINts PTHReshold PWAVerage STATe WLIMit STATe Syntax Attribute Summary Description Programming Commands CALCulate2 Subsystem DATA Queries the corrected peak data of the input laser line CALCulate2 DATA FREQuency POWer WAVelength WNUMber Constant Description FREQuency Queries the array of laser line frequencies after the peak search is completed If CALC2 PWAV STAT is on the power weighted average frequency is returned POWer Queries the array of laser line powers after the peak search is completed If CALC2 PWAV STAT is on the total input power is returned WaAVelength Queries the array of laser line wavelengths after the peak search is completed If CALC2 PWAV STAT is on the power weighted average wavelength is returned WNUMber Queries the array of laser line wave numbers after the peak search is completed If CALC2 PWAV STAT is on the power weighted average wave
192. t STATe Turns the drift measurement calculation on and off CALCulate3 POINts Queries the number of points in the data set CALCulate3 SNR AUTO Selects the internal or externally entered frequency value for the noise measurement reference in the SNR calculation CALCulate3 SNR REFerence FREQuency Sets the frequency used for the noise measurement reference in the SNR calculation CALCulate3 SNR REFerence WAVelength Sets the wavelength used for the noise measurement reference in the SNR calculation CALCulate3 SNR REFerence WNUMber Sets the wave number used for the noise measurement reference in the SNR calculation CALCulate3 SNR STATe Turns the SNR calculation on and off DISPlay Subsystem DISPlay MARKer MAXimum Sets the marker to the signal with the largest power DISPlay MARKer MAXimum LEFT Moves marker to signal with the next lower wavelength or frequency DISPlay MARKer MAXimum NEXT Moves the marker to the signal with the closest power level just below the power level of the signal at the current marker position DISPlay MARKer MAXimum PREVious Moves the marker to the signal with the closest power level just above the power level of the signal at the current marker position DISPlay MARKer MAXimum RIGHt Moves marker to the next higher wavelength or frequency DISPlay WINDow GRAPhics STATe Turns the instrument display of the power bars on and off S 3 48 Programming Lists of Commands Table
193. tep 16 and Step 17 to calculate the power correction offset value as shown in the following equation minimum drift maximum drift offset LO OI ON OS Pwr Enter the calculate value on the following line power correction offset 19 Change the attenuator to the settings shown in Table 5 6 For each setting record the power measured on the HP 86120A After completing this step the table s column titled HP 86120A Power Reading should be completely filled in 20 Calculate the Linearity value for each row in the table using the following equation Linearity Power Meter Reading HP 86120A Power Reading offset 5 27 Servicing Testing Performance 21 Compare the linearity values with the specification listed in Chapter 6 Specifications and Regulatory Information The data may show multiple amplitude plateaus separated by small amplitude steps This is not a problem as long as the amplitude steps are within the linearity specification 5 28 Servicing Testing Performance Table 5 6 Linearity Data Values Desired Power Attenuator Power Meter HP 86120A dBm Setting Reading Power Reading Linearity 0 1 2 3 5 29 Servicing Replacing Instrument Assemblies Replacing Instrument Assemblies This section provides step by step procedures to remove and replace the major instrument assemblie
194. ter Preset Key Pressed Power Turned On Display mode single wavelength last state Wavelength range limiting on ast state Measurement acquisition continuous ast state Wavelength calibration vacuum ast state Elevation correction value not affected ast state Wavelength units nm ast state Amplitude units dBm ast state Power offset 0 dB ast state Peak threshold 10 dB ast state Peak excursion 15 dB ast state Measurement speed normal ast state Drift measurements off off Delta Measurements A power off off A wavelength off off Signal to Noise Measurements measurement off off user frequency 193 4144 THz last state user wavelength 1550 nm in vacuum last state 7 3 Reference Instrument Preset Conditions Table 7 1 Instrument Conditions 2 of 2 fom Settings after Settings after Preset Key Pressed Power Turned On HP IB address not affected last state Power bar display on last state a The term last state refers to the last setting that this parameter was in before the instrument power was turned off 7 4 Reference Menu Maps Menu Maps This section provides menu maps for the HP 86120A softkeys The maps show which softkeys are displayed after pressing a front panel key they show the relationship between softkeys The softkeys in these maps are aligned verti cally instead of horizontally as on the actual display This was done to con serve space and to make the maps easier to i
195. the byte The following table shows each bit in the status byte register and its bit weight The STB query does not affect the contents of the status byte register Table 4 6 Status Byte Register Bit Bit Weight Condition 7 128 Not Used 6 64 Master Summary Status MSS 5 32 Event Status Bit ESB 4 16 Message Available MAV 3 8 Not Used 2 4 Error queue status 1 2 Not Used 0 1 Not Used lt integer gt from 0 to 255 4 11 Example Syntax Description Example Syntax Description Query Response Example Programming Commands Common Commands OUT PUT 720 STB EN ER 720 Value PRINT Value TRG The TRG trigger command is identical to the group execute trigger GET message or RUN command TRG This command acquires data according to the current settings This command cannot be issued as a query If a measurement is already in progress a trigger is ignored and an error is generated The following example starts the data acquisition according to the current set tings OUTPUT 720 TRG TST The TST test query starts a self test on the instrument TST The result of the test is placed in the output queue A zero indicates the test passed and a non zero value indicates the test failed The instrument will ini tiate a measurement and check for any hardware errors after the measure ment is com
196. tkeys to enter the elevation in meters Entries jump in 500 meter steps from 0 m to 5000 m The elevation value selected with the softkeys must be within 250 meters of the actual elevation 5 Press RETURN to complete the entry Converting feet to meters If you know your elevation in feet you can convert this value to meters by using the fol lowing equation ft m 33281 Getting Started Step 7 Select Medium for Wavelength Values Step 7 Select Medium for Wavelength Values Because wavelength varies with the material that the light passes through the HP 86120A offers wavelength measurements in two mediums vacuum and standard air l 2 3 Press the Setup key Press the CAL softkey Make the following selection e Press VACUUM for wavelength readings in a vacuum e Press STD AIR for wavelength readings in standard air Press RETURN to complete the entry Definition of standard air Standard air is defined to have the following characteristics Barometric pressure 760 torr Temperature 15 C Relative humidity 0 Getting Started Step 8 Turn Off Wavelength Limiting Step 8 Turn Off Wavelength Limiting After the Preset key is pressed the input wavelength range is limited to mea suring lasers between 1200 nm and 1650 nm You can easily expand the input range to the full 700 nm to 1650 nm range with the following steps l Press the Preset key 2 Press the Set
197. ts the current measurement sequence and places the instrument in the idle state ABORt Preset State not affected SCPI Compliance standard Command Only If the instrument is configured for continuous measurements a new measure ment sequence will begin Otherwise the instrument stays in the idle state until a new measurement is initiated INITiate CONTinuous Selects single or continuous measurement acquisition INITiate CONTinuous ON OFF 1 0 Non sequential command Preset State on RST State off SCPI Compliance standard When on is specified the instrument continuously measures the input spec trum 4 78 Programming Commands TRIGger Subsystem Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrument Refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 for more information INITiate MMediate Initiates a new measurement sequence Syntax INITiate IMMediate Attribute Summary Non sequential command Preset State none SCPI Compliance standard Command Only Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrument Refer to Always force the HP 86120A to wait for non sequential commands on pag
198. turned are in ascending optical frequency The first value of the uncorrected frequency data corresponds to an optical frequency of 181 6879 THz 1650 041 nm The last value of the uncorrected frequency data corresponds to an optical frequency of 428 2793 THz 699 993 nm For example a laser line peak located at the 1 500th returned value has an optical frequency of frequency 181 6879 THz 1 499 7 226756 GHz 192 5208 THz or 1557 195 nm in vacuum When FAST measurement mode is selected the uncorrected frequency domain data consists of 16K 8 192 values The frequency spacing between elements is uniform and is equal to the reference laser frequency 473 6127 THz divided by 16K or 57 81405 GHz Note the spacing between values is not uni form in wavelength units The values returned are in ascending optical fre quency Only the frequency domain data corresponding to 700 1650 nm wavelength in vacuum is returned 4 268 values The first value of the uncorrected frequency data corresponds to an optical frequency of 181 652 THz 1650 37 nm The last value of the uncorrected frequency data corre sponds to an optical frequency of 428 344 THz 699 89 nm For example a laser line peak located at the 200th returned value has an optical frequency of frequency 181 652 THz 199 57 81405 GHz 193 157 THz or 1551 07 nm in vacuum If your program is aborted or interrupted after sending this query the HP 86120A continu
199. um DEFault lt integer gt represents logarithmic units in dB Valid range is 0 to 40 4 33 Attribute Summary Description Syntax Attribute Summary Programming Commands CALCulate2 Subsystem Constant Value MINimum 0 dB MAXimum 40 dB DEFault 10 dB Non sequential command Preset State 10 dB RST State 10 dB SCPI Compliance instrument specific A laser line is identified as a valid peak if its amplitude is above the maximum amplitude minus the peak threshold value The subtraction is done in dB units This setting works in conjunction with the peak excursion setting to determine which responses are located Refer to PEXCursion on page 4 32 Changing the peak threshold limit causes the instrument to reprocess the cur rent set of data Refer also to Defining Laser Line Peaks on page 2 13 The query response is the current value For example if the current value is set to 15 dB the following value is returned 15 Non sequential command Always use an OPC query or a WAI command to ensure that this command has the time to complete before sending any more commands to the instrument Refer to Always force the HP 86120A to wait for non sequential commands on page 3 13 for more information PWAVerage STATe Places the instrument in the power weighted average mode CALCulate2 PWAVerage STATe ON OFF 1 O Preset State off RST State off Descriptio
200. ument s cable assemblies and components from damage Be sure to use extra caution to avoid damaging the EMI springs If you damage an EMI spring you can order a new one using HP part number 8160 0656 The part that is ordered with this number can be cut to provide 8 replacement springs 7 Slide the cover assembly back onto the instrument chassis while applying pressure to the side of the cover that is opposite the handle attachment screws Make sure that the cover seats firmly into the channel on the back side of the front casting Gentle pressure ensures that the cover will not bind against the EMI screws Make sure that the seam in the cover is located on the bottom of the instru ment 5 31 WARNING CAUTION Servicing Replacing Instrument Assemblies To replace the Al Optical Block Assembly To avoid exposure to the laser path of a CLASS Illa LASER PRODUCT do not open the A1A1 A1A2 or A1A3 assemblies There are no serviceable components inside the A1A1 A1A2 or A1A3 assemblies S o A1A3 A1A1 A1A2 servopt Do not disturb any of the screws on the A1A1 A1A2 or A1A3 assemblies Loosening or tightening these screws destroys the amplitude and wavelength calibration so that the HP 86120A no longer meets its published specifications If the position of these screws is changed return the instrument to Hewlett Packard for service 3
201. up key 3 4 Press MORE and then WL LIM Press LIM OFF to remove the limits on wavelength range All responses in the full 700 nm to 1650 nm range are now displayed Getting Started Returning the Instrument for Service Returning the Instrument for Service The instructions in this section show you how to properly package the instru ment for return to a Hewlett Packard service office For a list of offices refer to Hewlett Packard Sales and Service Offices on page 7 20 If the instrument is still under warranty or is covered by an HP maintenance contract it will be repaired under the terms of the warranty or contract the warranty is at the front of this manual If the instrument is no longer under warranty or is not covered by an HP maintenance plan Hewlett Packard will notify you of the cost of the repair after examining the unit When an instrument is returned to a Hewlett Packard service office for servic ing it must be adequately packaged and have a complete description of the failure symptoms attached When describing the failure please be as specific as possible about the nature of the problem Include copies of additional failure information such as instrument failure settings data related to instrument failure and error mes sages along with the instrument being returned Please notify the service office before returning your instrument for service Any special arrangements for the instrument can be
202. ure Measurement Instruction 4 52 DISPlay Subsystem 4 53 FETCh Measurement Instruction 4 57 HCOPy Subsystem 4 58 MEASure Measurement Instruction 4 59 READ Measurement Instruction 4 60 SENSe Subsystem 4 61 STATus Subsystem 4 66 SYSTem Subsystem 4 71 TRIGger Subsystem 4 77 UNIT Subsystem 4 80 4 3 Syntax Description Programming Commands Common Commands Common Commands Common commands are defined by the IEEE 488 2 standard They control generic device functions which could be common among many different types of instruments Common commands can be received and processed by the instrument whether they are sent over the HP IB as separate program mes sages or within other program messages CLS The CLS clear status command clears all the event status registers sum marized in the status byte register CLS With the exception of the output queue all queues that are summarized in the status byte register are emptied The error queue is also emptied Neither the event status enable register nor the service request enable register are affected by this command After the CLS command the instrument is left in the idle state The com mand does not alter the instrument setting OPC and OPC actions are can celled This command cannot be issued as a query ESE The ESE event status enable command sets the bits in the event status enable register and enables the corresponding bits in the event stat
203. us regis ter 4 4 Syntax Description Query Response Example Programming Commands Common Commands ESE lt integer gt 5 ESE lt integer gt is an mask from 0 to 255 The event status enable register contains a mask value for the bits to be enabled in the event status register A bit set to one 1 in the event status enable register enables the corresponding bit in the event status register to set the event summary bit in the status byte register A zero 0 disables the bit Refer to the following table for information about the event status enable register bits bit weights and what each bit masks The event status enable register is cleared at power on The RST and CLS commands do not change the register The ESE query returns the value of the event status enable register Table 4 2 Event Status Enable Register Bit Bit Weight Enables 7 128 PON Power On 6 64 Not Used 5 32 CME Command Error 4 16 EXE Execution Error 3 8 DDE Device Dependent Error 2 4 QYE Query Error 1 2 Not Used 0 1 OPC Operation Complete a A high enables the event status register bit lt integer gt is an mask from 0 to 255 OUTPUT 720 ESE 32 In this example the ESE 32 command enables CME event summary bit bit 5 of the event status enable register Therefore when an incorrect program ming command is received the CME comm
204. ven when the laser is amplitude modulated the correct wavelength and power is displayed A laser modulated at high frequency in the RF or microwave range can also cause spurious wavelengths to be displayed especially when the modulation is of a repetitive nature such as that of PRBS or SONET digital formats In gen eral no spurious wavelengths will be displayed using preset instrument condi tions The preset condition includes peak excursion peak threshold and wavelength range limiting However increasing peak threshold can cause spu rious wavelengths to be displayed To control the wavelength range refer to To use the full wavelength range on page 2 9 Even when the laser being tested is modulated with repetitive formats the carrier s correct wavelength and power is displayed the wavelength and power of the spurious sidebands are incorrect 2 32 Making Measurements Measuring Total Power Greater than 10 dBm Measuring Total Power Greater than 10 dBm The maximum total power that can be measured by the HP 86120A is 10 dBm However with the addition of an external attenuator more power can be applied This may be necessary at the transmit end of a wavelength division multiplexed system where large signal levels are present By entering an amplitude offset equal to the amount of attenuation at the instrument s input accurate amplitude measurements are shown on the display Additional ampli fication can also be a
205. ver 580 kilobytes of data 34 123 values can be returned to the computer When FAST measurement update is specified over 72 kilobytes of data 4 268 values can be returned The following string is a typical example of the first few returned values 4 02646500E 001 6 78125100E 001 6 17986600E 001 4 26768200 E 001 4 80245300E 001 3 10491300E 001 1 13409400E 001 5 07 832500E 001 2 77746200E 001 3 89150500E 001 3 50217600E 001 7 34649800E 001 5 64983800E 000 Notice that only measurement values are returned to the computer There is no first value that indicates the number of values contained in the string as there is for example with the FETCh READ and MEASure commands Use the CALCulatel TRANsform FREQuency POINTs command to query the number of points the CALC1 DATA returns When NORMAL measurement mode is selected the uncorrected frequency domain data consists of 64K 65 536 values Only the frequency domain data corresponding to 700 1650 nm wavelength in vacuum is returned 34 123 values In FAST measurement mode the data consists of 16K 8 192 values of which 4 268 values are returned 4 26 Programming Commands CALCulate1 Subsystem The frequency spacing between values is uniform and is equal to the reference laser frequency 473 6127 THz divided by 64K or 7 226756 GHz Note the spacing between values is not uniform in wavelength units The values re
206. wer Sensitivity is defined as the minimum power level of a single laser line input to measure wavelength and power accurately A laser line with less than the minimum power may be measured but with reduced wavelength and power accuracy For multiple laser lines input sensitivity may be limited by total input power Selectivity indicates the ability to measure the wavelength and power of a weak laser line in the proximity of a specified stronger laser line and separated by the specified amount Maximum displayed level indicates the maximum total input power total of all laser lines present to accurately measure wavelength and power Maximum safe input power indicates the maximum total input power total of all laser lines present to avoid permanent optical damage to the instru ment Maximum number of lines input is the maximum number of displayed lines If more than 100 lines are input only the 100 longest wavelength lines are dis played Input Return Loss indicates the optical power reflected back to the user s fiber cable relative to the input power It is limited by the return loss of the front panel connector and assumes the user s connector is good 6 4 Specifications and Regulatory Information Definition of Terms Measurement Cycle Measurement cycle time refers to the cycle time when measuring wavelength Time and power of laser lines Specific advanced applications may require longer cycle times 6 5 Spec
207. x 0 7 12 mm long 1 2110 0703 1 Fuse 6 3A 250V 2 0515 2032 2 Screw TORX T10 Flat Head M3 x 0 5 8 mm long 3 3050 0894 4 Washer flat 5 0mm 5 4 mm ID 9 85 mm OD 4 2190 0587 4 Washer lock HLCL 5 0mm 5 1 mm ID 9 2 mm OD 5 0515 1218 4 Screw socket head cap hex recess M5 x 0 8 40 mm long 6 5041 8929 2 Foot rear 7 86120 20008 1 Rear frame 8 3160 0309 1 Fan grille 9 0515 0383 4 Screw TORX T15 Pan Head M4 x 0 7 16 mm long 5 52 131415 16 Servicing Replaceable Parts rprea 5 53 Servicing Replaceable Parts Table 5 11 Top View Parts Item are Oty Description 1 1400 0968 2 Cable clip 0 75 in x 0 75 in 2 1400 0755 3 Component clip 0 75 in x 0 75 in 3 1400 1328 2 Cable mount 1 in x 1 in 4 1400 2136 1 Cable mount 0 75 in x 0 75 in 5 0515 0372 4 Screw TORX T10 Pan Head M3 x 0 5 8 mm long 6 86120 00011 1 Shield for A2 Power Supply 7 0515 0380 4 Screw TORX T15 Pan Head M4 x 0 7 10 mm long 5 54 Servicing Replaceable Parts is w Q O lt n eo N rpto 5 55 Servicing Replaceable Parts Table 5 12 Bottom View Parts Item eee Oty Description 1 1400 1439 2 Cable clip 2 0515 0372 1 Screw TORX T10 Pan Head M3 x 0 5 8 mm long 3 0515 0430 8 Screw TORX T10 Pan Head M3 x 0 5 6 mm long 4 86120 20018
208. y Converting feet to meters If you know your elevation in feet you can convert this value to meters by using the fol lowing equation fi m 3251 To select the medium for light 1 Press the Setup key 2 Press the CAL softkey and make the following selection e Press VACUUM for wavelengths in a vacuum e Press STD AIR for wavelengths in standard air 3 Press RETURN to complete the entry Making Measurements Printing Measurement Results Printing Measurement Results Measurement results can be sent directly to a printer Simply connect a com patible printer to the rear panel PARALLEL PRINTER PORT connector The output is ASCII text An example of a compatible printer is an Hewlett Packard s LaserJet series printer Be sure to use a parallel printer cable to connect the printer The printer output is not a copy of the display Rather it is a listing of all sig nals present at the input up to 100 The measurement values printed depend on the settings of the instrument when the Print key is pressed The following is an example of a typical printout HP 86120A SER US36151025 Firmware Ver 1 000 List By Wavelength 8 Lines Power Offset 0 0 dB Vacuum Elevation 0 Meters Update Normal Peak Excursion 15 dB Peak Threshold 10 dB Input Wavelength Power 1280 384nm 16 97dBm 1281 473 13 14 1282 569 13 92 12832651 13 34 1284 752 1 169 1285 840 0 eL 1286 944 10 38 1288 0
209. y lt size gt parameter sent will be ignored by the instrument No syntax error will be generated if a lt size gt parameter is sent Always force the HP 86120A to wait for non sequential commands The HP 86120A normally processes its remote programming commands sequentially The instrument waits until the actions specified by a particular command are completely finished before reading and executing the next com mand However there are a few non sequential commands where this is not true Non sequential commands do not finish executing before the next com mand is interpreted The following is a list of the HP 86120A s non sequential commands CALCulate1 TRANsform FREQuency POINTs CALCulate2 PE XCursion CALCulate2 PTHReshold CALCulate2 WLIMit STATe CALCulate3 SNR AUTO SENSe CORRection ELEVation INITiate CONTinuous INITiate IMMediate The following additional commands are also non sequential commands if CALCulate3 SNR AUTO is set to OFF CALCulate3 REFerence FREQuency CALCulate3 REFerence WAVelength CALCulate3 REFerence WNUMber The benefit of non sequential commands is that in some situations they can reduce the overall execution times of programs For example you can set the peak excursion peak threshold and elevation and use a WAI command at the end to save time However non sequential commands can also be a source of annoying errors Always use the OPC query or WAI command with the non sequ
210. y Subsystem A HCOPy Subsystem Use the command in this subsystem to print the displayed measurement results to a printer This subsystem has the following command hierarchy HCOPy IMMediate IMMediate Prints measurement results on a printer Syntax HCOPy IMMediate Attribute Summary Preset State none RST State none SCPI Compliance standard Command Only Description Connect the printer to the HP 86120A s rear panel PARALLEL PRINTER PORT con nector The output to the printer is ASCII text Programming Commands MEASure Measurement Instruction MEASure Measurement Instruction For information on the MEASure measurement instruction refer to Measure ment Instructions on page 4 14 4 59 Programming Commands READ Measurement Instruction READ Measurement Instruction For information on the READ measurement instruction refer to Measure ment Instructions on page 4 14 Programming Commands SENSe Subsystem SENSe Subsystem Use the SENSe commands to correct measurement results for elevation above sea level and to select between measurements in air or vacuum You can also enter an amplitude offset The commands in this subsystem have the following command hierarchy SENSe CORRection ELEVations gt MEDium OFFSet MAGNitude DATA Syntax Attribute Summar Description Querry Response Programming Commands SENSe Subsystem CORRection EKLEVation S

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