Agilent Technologies 6800 Yard Vacuum User Manual
Contents
1. In this example the voltage and frequency tran sients will be executed as an integrated test sequence 14 Agilent 6800 series features used RMS voltage and frequency control in List mode RMS voltage slew control List dwell time control e Triggering system to execute the List Advantages benefits of the Agilent 6800 series solution The List capability allows the ac power source analyzer outputs to sequence through each RMS voltage and frequency setting with accurate timing according to the standard and without controller intervention e By using the programmable RMS voltage slew control the RMS voltage level excursions can be faithfully reproduced as per the standard The List settings for MIL STD 704D are stored in non volatile memory so the test need only be set up once and then executed as needed Implementation details How the 6800 series implements MIL STD 704D RMS voltage and frequency transients The computer sets up List sequence then ac power source analyzer is sent a bus trigger Upon receipt of the trigger the ac power source analyzer s out put is set according to the voltage voltage slew and frequency values of the first List point The output will remain at the first List point setting until the dwell time for that List point expires The unit will then sequence through each successive List point paced by the respective dwell times until the List is completed Upon completion of the Li2. External Trigger In This is the 6800 series TRIGGER IN connector It accepts TTL levels with the falling edge detected as the trigger TTL Trigger The TTL trigger is an internal trigger that causes the acquisition of digitized voltage and current data This internal trigger can be generated when an output transient begins or ends or as the result of List step execution How Can Triggers be Generated The 6800 series can generate a trigger on the TRIGGER OUT connector as a result of the follow ing actions e the beginning of a Step Pulse or List output transient e the completion of a Step or Pulse output transient e the completion of a List sequence e the beginning of a List step The TRIGGER OUT signal is a nominal 10 microsecond low true pulse How Can the Agilent 6800 Series be Enabled to Respond to a Trigger The default state of the ac power source analyzer is the idle state where trigger detection is disabled To respond to a trigger it must be placed in the initiated state This can be done via the front panel or over the bus Once initiated the ac power source analyzer can detect a trigger from the selected source When the trigger is detected the ac power source analyzer will perform the trigger action after wait ing any programmed trigger delay time Upon com pletion of the trigger action the ac power source analyzer will return to the idle state Idle State Continuous Tri
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4. Result Computed from Buffers Calculated Measurement Returned via Bus FETCh Command Executing the FETCh command returns the requested measurement from previously acquired buffers of data MEASure and FETCh Command Execution Diagram Applications The following section contains six application examples For each application there is e An overview of the application e A description of the Agilent 6800 series features used to implement the application e The advantages and benefits of the 6800 series solution Application e The details of the implementation of the solution e A sample program in QBASIC using the National GPIB interface card e A description of variations on the application if applicable The following table lists the 6800 series features used in each of the applications Transient Generation Step mode e Pulse mode e List mode Transient generation with a trigger delay Synchronization with output phase e e User defined waveform generation Voltage slew control e Frequency slew control Measurement and Analysis Synchronization with transients Harmonic analysis e Measurement window control High resolution current range measurements Digitized data acquisition e Event referenced data acquisition Data acquisition sample rate control 10 Application 1 Simulating AC Line Sub Cycle Dropouts Over
5. 409 points Enable the output of the ac power source analyzer Initiate the transient trigger Initiate the acquisition trigger Send a Bus trigger Fetch the peak current measurement Output Voltage Start up phase of 40 degrees Inrush Current p i i i i i i i i i i i i i i H i MH i H Data Points 10 ms of VA Pre event Current Data Digitized Inrush Current Bus Trigger SE ee an oo Peak Current Measurement j j pls Ht Upon receipt of the trigger the ac power source analyzer output goes to 120 Vrms when the phase voltage waveform reaches 40 The data buffer acquires 409 instantaneous current data points before the turn on event and 3687 instantaneous current data points beginning at the onset of the turn on event for a total buffer of 4096 current data points to generate the peak current measure ment To continue the peak inrush current charac terization change the synchronization phase from 40 to 50 60 70 80 and 90 and repeat the same procedure Timing Diagram for Application 4 22 Program for Application 4 Performing Inrush Current Measurements Program APP_4 BAS DECLARE SUB ADDRESS DECLARE SUB COMMAND ADDR CMD DECLARE SUB ENTER ADDR RESULTS ACS 5 CALL ADDRESS CALL COMMAND ACS RST CALL COMMAND ACS VOLT 0 CALL COMMAND ACS VOLT MODE STEP CALL COMMAND ACS VOLT TRIGGERE
6. Set harmonic number and amplitudes for Class 1 waveform Comps DATA 1 120 DATA 3 9 6 DATA 5 10 8 DATA 7 6 DATA 11 2 4 DATA 13 2 4 DATA 0 0 Ensure array is dimensioned properly FOR I 0 TO 1023 Wfdata I 0 NEXT I Create the Class 1 waveform RESTORE Comps HARMLOOP READ Harm READ Ampl IF Harm 0 THEN GOTO Download FOR I 0 TO 1023 Wfdata D Wfdata I Ampl SIN 2 PI Harm I 1024 NEXT I GOTO HARMLOOP Name the waveform CLASS1 and download to the ac source Download CALL COMMAND ACS TRACE DEFINE LTRIM Shapename WFSTR TRACE DATA LTRIM Shapename CALL COMMANDNOCRLF ACS WFSTR LEN WFSTR FOR I 0 TO 1022 WESTRS LTRIM STR Wfdata I CALL COMMANDNOCRLF ACS WFSTR LEN WFSTRS NEXT I WESTR LTRIM STRS Wfdata 1023 CALL COMMAND ACS WFSTR Create the List transient to test to the standard 26 Subroutine to send command strings without a CRLF Subroutine to send a command string Subroutine to send command strings Set ac source address variable to 5 Open communication to address 5 Lists CALL COMMAND ACS VOLT MODE LIST CALL COMMAND ACS FREQ MODE LIST CALL COMMAND ACS FUNC SHAPE MODE LIST CALL COMMAND ACS LIST VOLTAGE 120 120 120 CALL COMMAND ACS LIST FREQUENCY 60 60 60 CALL COMMAND ACS LIST SHAPE SIN CLASS1 SIN CALL COMMAND ACS LIST DWELL 120 120 120 CALL COMMAND ACS LIST STEP
7. Set the trigger to occur at an output phase of 40 degrees Increase this output phase to 90 degrees in 10 degree increments for full inrush current characterization Set the GPIB as the transient trigger source Set the measurement trigger source to the internal trigger Enable the internal trigger source Capture 409 samples of pre trigger data Initiate the transient trigger Initiate the measurement trigger Send the bus trigger Make a peak current measurement from acquired data Read the peak current measurement Turn off the ac source output Print the peak current measurement 23 Application 5 Generating User Defined Waveforms Overview of application The creation of user defined waveforms is useful for simulating ac line disturbances that are unique to the operational environment of the device being tested and then measuring that device s suscepti bility to the disturbance This is the fundamental objective of environmental test standards that per tain to the ac line A specific example is the draft for IEC 77A Secretariat 101 draft dated 10 15 93 which defines the test and measurement methods for evaluating electronic and electrical equipment immunity to voltage harmonics and inter harmon ics on the ac line Upon subjecting the equipment to the voltage harmonics it must recover to its full operative capabilities to meet the pass criteria of this draft For this example a wa
8. VOLT 230 CALL COMMAND ACS FREQ 16 6 CALL COMMAND ACS OUTPUT ON CALL COMMAND ACS SENSE CURRENT ACDC RANGE MIN CALL COMMAND ACS SENSE SWEEP TINTERVAL 75E 6 CALL COMMAND ACS TRIGGER SEQ3 SOURCE BUS CALL COMMAND ACS INITIATE SEQ3 CALL COMMAND ACS TRG Measure read and print the VA Watts and power factor measurements CALL COMMAND ACS FETCH POWER AC APPARENT CALL ENTER ACS VARdg CALL COMMAND ACS FETCH POWER AC CALL ENTER ACS WRdg CALL COMMAND ACS FETCH POWER AC PFACTOR CALL ENTER ACS PFRdg PRINT VARdg WRdg PFRdg END Subroutines SUB ADDRESS OPEN GPIBO FOR OUTPUT AS 1 OPEN GPIBO FOR INPUT AS 2 PRINT 1 ABORT PRINT 1 GPIBEOS IN LF END SUB SUB COMMAND ADDR CMD C OUTPUT STRS ADDR CMD PRINT 1 C END SUB SUB ENTER ADDR RESULTS PRINT 1 enter STR ADDR LINE INPUT 2 RESULTS END SUB Subroutine to open ac source communication Subroutine to send command strings Subroutine to return ac source measurements Set ac source variable address to 5 Open communication to address 5 Set number of spaces in VA measurement string Set number of spaces in Watts measurement string Set number of spaces in Power Factor measurement string Reset the ac source Set the immediate voltage to 230 Vrms Set the immediate frequency to 16 6 Hz Turn on the ac source output Use
9. and the beginning of acquisition relative to the trigger The ac power source analyzer has a sample rate of approximately 40 kHz a sample every 25 microseconds as the default setting This means it takes approximately 100 milliseconds for the data buffers to fill with voltage and current data points The sample period can be programmed from a minimum of 25 microseconds to a maxi mum of 250 microseconds at 25 microsecond increments The acquisition of voltage and current data can also be initiated relative to the acquisition trigger thereby enabling the capture of pre event and post event data To capture pre event or post event voltage and current data the offset of data points relative to the trigger is programmed The range of offset that can be programmed is from 4096 to 2x10 points If the offset is negative the values at the beginning of the data buffer represent samples taken prior to the trigger If the offset value is zero the default setting all data is acquired directly after the trigger If the offset value is positive the acquisition of valid buffer data will be delayed from the receipt of the trigger Executing the MEASure MEASure Command command automates the triggering and data acquisition and retums the requested measurement Sampie Period set to 25 microseconds Acquisition Offset set to Zero Trigger initiated Trigger Received Voltage and Current Buffers Acquired
10. nates the worry of synchronizing separate instru ments The ability to turn on relative to the output voltage phase allows worst case inrush characteri zation which results in a more reliable product Implementation details How the 6800 series implements peak inrush current measurements The RMS voltage is programmed to Step mode to generate a turn on condition from 0 Vrms to 120 Vrms The turn on is synchronized to the phase of the output voltage The current measure ment is programmed to occur at turn on with 10 milliseconds of pre event data to ensure that the full inrush event is captured To characterize the inrush current of the unit under test the turn on phase is initially set to 40 for the first peak inrush current measurement and is then increased at 10 increments up to 90 for succeeding peak inrush current measurements Between tests the input capacitors of the unit under test are allowed to fully discharge for proper characterization 21 Agilent 6800 series setup Set the initial immediate voltage to 0 Vrms Set the triggered voltage level to 120 Vrms e Set the frequency to 60 Hz e Set the peak current limit to maximum Set the transient trigger source to BUS e Set the trigger synchronization source to Phase Set the initial synchronization Phase to 40 re program to 50 60 70 80 and 90 Set the acquisition trigger source to TTLTrg e Set the data acquisition offset to
11. 5963 7044E Agilent Technologies Innovating the HP Way
12. DATa command to send the 1024 point array to the ac power source analyzer Set the List to sequence automatically Set the transient trigger source to BUS Initiate the transient trigger Enable the output Send a Bus trigger Upon receipt of the trigger the first List step is executed and the output is set to a 120 Vrms 60 Hz sinewave After 120 seconds the ac power source analyzer automatically executes the second List step The output will remain at the CLASS 1 test level for 120 seconds and then will execute the third List step After the entire List is executed the output of the ac power source analyzer will List Point Shape Dwell Time return to the Fixed mode levels 1 Sine 120 s 2 CLASS1 120 s 3 Sine 120 s IEC 77A Secretariat 101 Draft Clase 1 Waveform 140 120 F 100 H BOE 60 pot 20 F 2 of B ol BEDE 40 60 80 100 420 E 140 F Point 1 Point 2 Point 3 Sinewave CLASS1 Sinewave 120 Vrms 120 seconds 120 seconds 120 seconds tigger Timing Diagram for Application 5 25 Program for Application 5 Generating User defined Waveforms Program APP_5 BAS DECLARE SUB COMMANDNOCRLF ADDR CMD LENGTH DECLARE SUB ADDRESS DECLARE SUB COMMAND ADDR CMD ACS 5 CALL ADDRESS Set the variables OPTION BASE 0 DIM Wfdata 1024 DIM WFSTR 5000 Shapename CLASS1 PI 3 141593 Frequency 60
13. Operating the Agilent 6812A and 6813A at Low Frequencies Introduction to the Agilent 6800 AC Power Source Analyzer The 6800 series ac power source analyzers are members of the Agilent Technologies One Box Solution power products family These products offer an integrated solution for ac power testing applications The 6800 series combines the functionality of the following instruments in one box e power amplifier e arbitrary waveform generator e power analyzer harmonic analyzer e waveform digitizer The power amplifier and arbitrary waveform generator capabilities produce waveforms with programmable amplitude frequency and wave shape Each model has pre programmed sine square and clipped sine waveshapes For added flexibility twelve user defined waveforms can be created and stored in non volatile memory Waveforms can be programmed using the 6800 series transient generation system to simulate sophisticated and repeatable ac line disturbances or output sequences The power analyzer and harmonic analyzer capa bilities provide high precision measurements including e rms dc ac dc voltage and current e peak voltage and current real apparent and reactive power harmonic analysis of voltage and current wave forms providing amplitude and phase up to the 50th harmonic e total harmonic distortion e triggered acquisition of digitized voltage and current The 6800 series can be used in bench or ATE ap
14. Program for Application 3 Performing TEC 555 2 Measurements Program APP_3 BAS DECLARE SUB ADDRESS DECLARE SUB COMMAND ADDR CMD DECLARE SUB ENTER ADDR RESULTS IHARM SPACE 1500 ACS 5 CALL ADDRESS CALL COMMAND ACS RST CALL COMMAND ACS VOLT 230 CALL COMMAND ACS CURRENT PEAK MAX CALL COMMAND ACS FREQ 50 CALL COMMAND ACS SENSE WINDOW RECT CALL COMMAND ACS OUTPUT ON SLEEP 10 CALL COMMAND ACS MEASURE ARRA Y CURRENT HARMONIC CALL ENTER ACS IHARM Use the computer to compare the measured harmonics to IEC 555 2 limits END Subroutines SUB ADDRESS OPEN GPIBO FOR OUTPUT AS 1 OPEN GPIBO FOR INPUT AS 2 PRINT 1 ABORT PRINT 1 GPIBEOS IN LF END SUB SUB COMMAND ADDR CMD C OUTPUT STR ADDR CMD PRINT 1 C END SUB SUB ENTER ADDR RESULTS PRINT 1 enter STR ADDR LINE INPUT 42 RESULT END SUB 20 Subroutine to open ac source communication Subroutine to send command strings Subroutine to return ac source measurements Set maximum number of spaces for measurment Set ac source address to 5 Open commuication to address 5 Reset the ac source Set the immediate voltage to 230 Vrms Set the peak current limit to maximum Set the immediate frequency to 50 Hz Use a Rectangular measurement window as per the stan Turn on the ac source output Wait 10 seconds for a steadystate c
15. electrical system and the electronic equipment utilizing this power on board the aircraft When testing to this standard electrical aircraft equip ment must be subjected to voltage and frequency transients that can occur under normal operation emergency power operation and during power source transfers The pass criteria for aircraft equipment is depend ent upon the specification of the equipment under test In general the intent of the test is that e the equipment is permitted a degradation or loss of function unless required otherwise by its specifications e the equipment is not permitted to produce a damaging or unsafe condition e the equipment must automatically recover full specified performance when normal ac power characteristics are restored For this example the equipment under test has a single phase ac input with 115 Vrms and 400 Hz requirements The device is tested under ac voltage transients initially and then under frequency tran sient conditions These transients are as follows At 400 Hz Voltage Test 1 180 Vpk 127 Vrms for 10 ms and then slew to 124 Vpk 88 Vrms at 800 Vpk 566 Vrms per second Voltage Test 2 80 Vpk 57 Vrms for 10 ms and then slew to 108 Vpk 76 Vrms at 400 Vpk 283 Vrms per second At 115 Vrms Frequency Test 1 425 Hz for 1 s 420 Hz for 4 s 410 Hz for 5 s and 407 Hz for 4 s Frequency Test 2 375 Hz for 1 s 380 Hz for 4 s 390 Hz for 5 s and 393 Hz for 4 s
16. is assured that the power supply is in steadystate operation e One command initiates the test Implementation details How the 6800 series implements the dropout The computer sends a trigger to the ac power source analyzer with a programmable delay of 5 seconds to ensure that the ac input to the power supply under test is in a steadystate condition The ac source outputs a low distortion 120 Vrms sinewave during the trigger delay and allows the power supply to stabilize into steadystate opera tion After 5 seconds the ac power source analyzer responds to the trigger and drops the output volt age to 0 Vrms starting at 80 of one output voltage cycle and lasting for 0 001389 seconds Agilent 6800 series setup e Connect the ac source output to the ac input of the power supply under test e Set the output waveform to sine Set the rms voltage to Pulse mode Set the initial immediate voltage to 120 Vrms Set the triggered voltage level to 0 Vrms e Set the frequency to 60 Hz Set the Pulse count to 1 Set the Pulse width to 0 001389 seconds the width of 30 of phase dropout for a 60 Hz sinewave Set the transient trigger source to BUS Set the transient trigger source synchronization to PHASE Set the phase synchronization to 80 Set the trigger delay to 5 seconds Initiate the transient trigger system Enable the output of the ac power source analyzer Send a bus trigger Upon the
17. the high resolution current measurement range Set the sample period to 75 microseconds Set the GPIB as the measurement trigger source Initiate the measurement trigger 29 Agilent Technologies Test and Measurement Support Services and Assistance Agilent Technologies aims to maximize the value you receive while minimizing your risk and problems We strive to ensure that you get the test and measurement capabilities you paid for and obtain the support you need Our extensive support resources and services can help you choose the right Agilent products for your applications and apply them successfully Every instrument and system we sell has a global warranty Support is available for at least five years beyond the produc tion life of the product Two concepts underlie Agilent s overall support policy Our Promise and Your Advantage Our Promise Our Promise means your Agilent test and measurement equip ment will meet its advertised performance and functionality When you are choosing new equipment we will help you with product information including realistic performance specifica tions and practical recommendations from experienced test engineers When you use Agilent equipment we can verify that it works properly help with product operation and provide basic measurement assistance for the use of specified capabili ties at no extra cost upon request Many self help tools are available Your Advantage
18. 30 Vrms sinewave is programmed at a frequency of 16 6 Hz To perform measurements at this out put frequency the programmable sample period is increased from 25 microseconds to 75 microsec onds A triggered acquisition of voltage and current provide the data from which the power measure ments are calculated This method of acquisition is necessary since the MEASure command will reset the sample period back to the default value of 25 microseconds A FETCh command is sent to return the real power Watts power factor and apparent power measurements from the same voltage and current data buffer Agilent 6800 series setup e Connect the ac source output to the ac input of the equipment under test e Set the regulation mode to Realtime Set the rms voltage to Fixed mode e Set the frequency to Fixed mode Set the shape to sine Set the rms voltage to 230 V e Set the frequency to 16 6 Hz Enable the output e Set the measurement sample period to 75 microseconds Trigger the acquisition of voltage and current data Fetch the real power Fetch the power factor Fetch the apparent power Program for Application 6 Operating the 6812A and 6813A at Low frequencies Program APP_6 BAS DECLARE SUB ADDRESS DECLARE SUB COMMAND ADDR CMD DECLARE SUB ENTER ADDR RESULTS ACS 5 CALL ADDRESS VARdg SPACES 50 WRdg SPACES 50 PFRdg SPACES 50 CALL COMMAND ACS RST CALL COMMAND ACS
19. AUTO CALL COMMAND ACS OUTPUT ON CALL COMMAND ACS TRIGGER SEQ1 SOURCE BUS CALL COMMAND ACS INITIATE SEQ1 CALL COMMAND ACS TRG END Subroutines SUB ADDRESS OPEN GPIBO FOR OUTPUT AS 1 OPEN GPIBO FOR INPUT AS 2 PRINT 1 ABORT PRINT 1 GPIBEOS IN LF END SUB SUB COMMAND ADDR CMD C OUTPUT STRS ADDR CMDS PRINT 1 C END SUB SUB COMMANDNOCRLF ADDR CMD LENGTH Set the rms voltage to operate in the List transient mode Set the frequency to operate in the List transient mode Set the waveshape to operate in List transient mode Set the rms voltage List points Set the frequency list points Set the waveshape List points Set the List point dwell times Set the List to be dwell time paced Turn on the ac source output Set the GPIB as the transient trigger source Tnitiate the transient trigger Send the bus trigger C OUTPUT STRS ADDR 4 STR LENGTH NOEND CMD PRINT 1 C END SUB 27 Application 6 Operating the Agilent 6812A and 6813A at Low Frequencies Overview of application For some applications such as the simulation of European railway power systems a low frequency 16 6 Hz ac waveform is required Generating low frequency waveforms with ac sources can present testing challenges due to output power derating and programming inaccuracies depending on the regulation technique used If th
20. Agilent 6800 Series AC Power Source Analyzer Product Note Using the Agilent Technologies 6800 Series AC Power Source Analyzers for Generation and Measurement 1158 600 B el Applications Simulating AC Line Sub Cycle Dropouts e Generating MIL STD 704D Waveforms e Performing IEC 555 2 Measurements Performing Inrush Current Measurements Generating User Defined Waveforms Operating the Agilent 6812A and 6813A at Low Frequencies Agilent Technologies Innovating the HP Way Introduction This note provides information on how you can use the features of the Agilent Technologies 6800 series ac power source analyzers to address a variety of applications Although your exact appli cation may not be listed here the capabilities described can be generalized and applied to your specific needs The programming examples are given in QBASIC These are the capabilities that are discussed and a description of how they can be applied Table of Contents Introduction to the Agilent 6800 AC Power Source Analyzer Agilent 6800 Series Output Transients Agilent 6800 Series Triggering Agilent 6800 Series Measurements Application 1 Simulating AC Line Sub Cycle Dropouts Application 2 Generating MIL STD 704D Waveforms Application 3 Performing IEC 555 2 Measurements Application 4 Performing Inrush Current Measurements Application 5 Generating User Defined Waveforms Application 6
21. D 120 CALL COMMAND ACS CURRENT PEAK MAX CALL COMMAND ACS OUTPUT ON CALL COMMAND ACS TRIGGER S YNCHRONIZE SOURCE PHASE CALL COMMAND ACS TRIGGER SYNCHRONIZE PHASE 40 CALL COMMAND ACS TRIGGER SEQ1 SOURCE BUS CALL COMMAND ACS TRIGGER SEQ3 SOURCE TTLT CALL COMMAND ACS OUTPUT TTLT ON Li CALL COMMAND ACS SENSE SWEEP OFFSET POINTS 409 CALL COMMAND ACS INITIATE SEQI CALL COMMAND ACS INITIATE SEQ3 CALL COMMAND ACS TRG CALL COMMAND ACS FETCH CURRENT AMPLITUDE MAX CALL ENTER ACS IPEAK CALL COMMAND ACS OUTPUT OFF PRINT IPEAK END Subroutines Li SUB ADDRESS OPEN GPIBO FOR OUTPUT AS 1 OPEN GPIBO FOR INPUT AS 2 PRINT 1 ABORT PRINT 1 GPIBEOS IN LF END SUB SUB COMMAND ADDR CMD C OUTPUT STRS ADDR CMD PRINT 1 C END SUB SUB ENTER ADDR RESULTS PRINT 1 enter STRS ADDR LINE INPUT 2 RESULTS END SUB Subroutine to open ac source communication Subroutine to send command strings Subroutine to read ac source measurements Set the ac source address to 5 Open communication to address 5 Reset the ac source Set the immediate voltage to 0 Vrms Set the rms voltage to operate in the Step transient mode Change the voltage to 120 Vrms on trigger Set the peak current to maximum Turn on the ac source output Set the trigger to occur referenced to the output phase
22. SE mode Count 1 TRIGgered levei CP in Count gt 1 IMMediate level LIST mode Trigger Applied i duty cycle m Step 1 ni List Complete Triggers ignored output always set to immediate command levels At trigger the triggered level becomes the new immediate level At trigger the triggered level is active during the pulse width portion of the pulse waveform At trigger the triggered level is active during the duty cycle portion of the pulse waveform At trigger the list starts When list completes the output retums to immediate level Steps 0 1 and 2 can be set to repeat from 1 to infinity upon receipt of trigger Model of the Transient System Agilent 6800 Series Triggering In ATE applications triggers are often a conven ient way of synchronizing test system events and increasing test throughput These benefits also apply to the triggering subsystems in the 6800 series products since these products combine the capabilities of many test instruments Each model is equipped with the ability to send and receive triggers and to perform or initiate a multitude of synchronized functions upon receiving a trigger Triggers can be used to change the output syn chronize a change to a phase of a waveform cycle and synchronize a measurement to an output change The effectiveness of the triggering capability can be shown when measuring worst case inrush current of a sw
23. TH 0 001389 CALL COMMAND ACS TRIGGER S YNCHRONIZE SOURCE PHASE CALL COMMAND ACS TRIGGER S YNCHRONIZE PHASE 80 CALL COMMAND ACS TRIGGER SEQ1 SOURCE BUS CALL COMMAND ACS TRIGGER DELAY 5 CALL COMMAND ACS INITIATE SEQ1 CALL COMMAND ACS OUTPUT ON CALL COMMAND ACS TRG END Subroutines SUB ADDRESS OPEN GPIBO FOR OUTPUT AS 1 OPEN GPIBO FOR INPUT AS 2 PRINT 1 ABORT PRINT 1 GPIBEOS IN LF END SUB SUB COMMAND ADDR CMD C OUTPUT STR ADDR CMD PRINT 1 C END SUB Subroutine to open ac source communication Subroutine to send command strings Set AC source address variable to 5 Open communication to address 5 Reset the ac source Set the immediate rms voltage to 120 Vrms Set the peak current limit to maximum Set the rms voltage to operate in Pulse mode Set the ac source to go to 0 Vrms on trigger Set the dropout duration Trigger referenced to the output phase Set the trigger to occur at 80 degrees of phase Set the GPIB as the transient trigger source Delay the transient trigger for 5 seconds Initialize the transient trigger Turn on the ac source output Send the bus trigger Application 2 Generating MIL STD 704D Waveforms Overview of application U S Military Standard 704D September 30 1980 establishes the requirements of electrical power transfer between the aircraft or ground support
24. e ac source has measurement capability control of the measure ment sample period is necessary to capture suffi cient cycles of the output waveform to ensure measurement accuracy The 6812A and 6813A can meet the above chal lenges at frequencies below 45 Hz These two models provide precise control of the waveform generation and measurement system for optimal operation at low frequencies For this example the equipment under test will require an ac input at 230 Vrms and 16 6 Hz Real power apparent power and power factor will be accurately meas ured using the high resolution current measure ment range Agilent 6812A and 6813A features used Programmable Vrms and frequency e Realtime regulation mode e Sinewave generation e Programmable voltage and current sample rate e Power measurement power factor VA and Watts e x10 current measurement range Advantages benefits of the Agilent 6812A and 6813A solutions e Programmable regulation mode allows for accu rate output voltage and current limit control Programmable measurement sample rate pro vides high accuracy measurements for low frequency signals e Use of the FETCh command provides fast measurements from the same data buffers e x10 current measurement range increases the accuracy for low current and low power measurements 28 Implementation details How the 6812A and 6813A generate low frequency ac waveforms and perform low frequency ac measurements A 2
25. e unit begins acquir ing new voltage and current data into its data buffers Upon completing the acquisition of 4096 data points for voltage and current the unit then performs the required calculation to return the requested measurement parameter When a new acquisition of instantaneous output voltage and current data is desired this command should be used to return the requested measurement What is a FETCh Command This command allows the user to retrieve meas ured parameters from previously acquired voltage and current data For example the FETCh com mand can be used after a MEASure command to return calculated parameters from the same 4096 data points that were acquired by the MEASure command In addition the FETCh command can be used to retrieve measurement information after triggering an acquisition of digitized voltage and current data This method provides the flexibility to synchronize the data acquisition with a triggered event and then return many calculations from the existing voltage and current data buffers Offset 4095 4096 Data Points Offset 2048 4096 Data Points Offset 0 Time Acquisition Trigger 4096 Data Points Offset Oto2E9 4096 Data Points Pre event and Post event Acquisition Triggering How Can the Acquisition of Voltage and Current Data be Controlled Two characteristics of the voltage and current acquisition can be controlled the sample rate
26. gger Initiation OFF Initiated State Continuous Trigger initiation ON List Not Complete or Trigger Paced List Delaying State Output Step Change Output Pulse Change Pulse Count Done Immediate Trigger Initiation Trigger Received Delay Completed Wait for Synchronization State Synch Completed Output List Change Complete or Trigger Paced List Output Transient Trigger Model Idle State Immediate Trigger Initiation Initiated State Trigger Received 4096 voltage points 4096 current points Measurement Trigger Model Agilent 6800 Series Measurements The built in power analyzer capability offers many voltage current and power measurements to the user While on the ac power source analyzers are continuously sampling instantaneous output volt age and current for several output cycles and writ ing the data to buffers Each buffer one for voltage and one for current holds 4096 data points The voltage and current data is used to calculate the requested measurement parameter There are two basic methods to obtain a measurement using the MEASure command or the FETCh command These commands can return a single measured parameter an array of voltage and current harmonic data or an array of the 4096 voltage or current data values What is a MEASure Command When this command is sent to the 6800 series ac power source analyzer th
27. igger Upon receipt of the trigger the List sequence will begin and the ac power source analyzer output will go to the setting represented in the first List step Each List step will be executed at the expiration of the programmed dwell time of the previous step After the last List step is executed the output of the ac source will change to the immediate output settings Fixed mode settings 9 II m FE i a re ly NU TIT MI su UNU ERE List Timing Diagram for Application 2 Program for Application 2 Generating MIL STD 704D Waveforms Program APP_2 BAS DECLARE SUB ADDRESS DECLARE SUB COMMAND ADDR CMD ACS 5 CALL ADDRESS CALL COMMAND ACS RST CALL COMMAND ACS VOLT 115 CALL COMMAND ACS CURRENT PEAK MAX CALL COMMAND ACS FREQUENCY 400 CALL COMMAND ACS VOLT MODE LIST CALL COMMAND ACS FREQ MODE LIST CALL COMMAND ACS VOLT SLEW MODE LIST CALL COMMAND ACS LIST STEP AUTO Subroutine to open ac source communication Subroutine to send command strings Set ac source address variable to 5 Open communication to address 5 Reset the ac source Set the immediate voltage to 115 Vrms Set the peak current to maximum Set the immediate frequency to 400 Hz Set the rms voltage to operate in the List transient mode Set the frequency to operate in the List transient mode Set the frequency slewing
28. irements Implementation details How the 6800 series implements IEC 555 quasi stationary harmonic current measurements The output of the ac power source analyzer is set to 230 V and 50 Hz The measurement window is changed from the default value KBessel to the Rectangular window To perform the harmonic analysis the ac power source analyzer is sent a command to measure an array of harmonic current amplitudes This array of current harmonics can be transferred to the computer for PASS FAIL analysis versus the limits of the standard Agilent 6800 series setup The ac source output is connected to the ac input of the equipment under test Set the output waveform to sine Set the rms voltage to Fixed mode Set the frequency to Fixed mode Set the voltage to 230 Vrms Set the frequency to 50 Hz Set the measurement window to Rectangular Enable the output of the ac power source analyzer Wait until the ac input to the equipment is in a steadystate condition Send the harmonic current array measurement command to return 50 harmonic current amplitudes see Voltage Current 25 15 Current Amplitude Amps 0 5 Steadystate Harmonic Number 20 Using the computer e Read the harmonic current array into the computer e Compare the measured harmonic current ampli tudes of harmonic numbers 2 through 40 to the IEC 555 2 quasi stationary standard limits 36 38 40 34 22 24
29. itching power supply Using the 6800 series triggering subsystem the output can be triggered to turn on at a phase near the peak of the ac cycle for simulating a worst case ac line condition Simultaneously the ac source can be triggered to take current measurements to charac terize the behavior of the power supply under test In addition triggering can be extended to external test equipment via the Trigger Out connection The 6800 series has two main triggering subsystems one for generating transients and one for making measurements These two subsystems have common trigger sources that can synchronize transient and measurement events What Actions Can be Triggered The following actions of the 6800 series can be triggered e a change in output setting e the start of a Step Pulse or List transient e the pace of a List sequence e the acquisition of digitized voltage and current e the synchronization of an output change to a phase of the cycle A programmable time delay can be specified for triggers that generate output changes This allows the insertion of a specified time delay between the receipt of the trigger and the action of the ac power source analyzer output What Can Serve as the Source of the Trigger The 6800 series can receive triggers from the following sources The GPIB The computer can send trigger commands to the ac power source analyzer There is a short command processing time associated with this source
30. mains This standard establishes limits on the amount of har monic energy electrical equipment can inject on the ac line to ensure that other devices connected to the ac power distribution system are not adversely affected The generated current harmonics can vary or fluctuate with time due to electronic products that cycle the ac line or can have steadystate quasi stationary characteristics When testing electronic equipment with a single phase ac input for compliance to the quasi stationary part of this standard it is necessary to have an ac source with low distortion and low output imped ance to avoid introducing unacceptable measure ment errors The measurement instrument must use the required Rectangular or Hanning meas urement window and must have the capability to return measured current amplitude data up to the 40th harmonic of the fundamental 18 Agilent 6800 series features used RMS Voltage and frequency control e Measurement window control e Harmonic current measurement Advantages benefits of the Agilent 6800 series e The 6800 series provides a One Box Solution so a separate power analyzer is not required for quasi stationary harmonic measurements e The 6800 series provides an IEC 555 compliant Rectangular measurement window built into the standard unit e The low distortion low output impedance and 16 bit measurement accuracy of the 6800 series provide full compliance to the measurement requ
31. ondition Measure the current harmonics Read the current harmonics Application 4 Performing Inrush Current Measurements Overview of application Switch mode power supplies are commonly used in many electronic products These power supplies typically have input capacitors that cause high levels of peak inrush current to be drawn as they charge from the rectified line at turn on The peak amplitude of the inrush current varies with the turn on phase of the ac voltage cycle Usually the highest peak inrush currents occur near the peak 90 of the voltage cycle Characterization of inrush current versus turn on phase allows for determination of worst case inrush current condi tions which must be determined to properly select fuses and circuit breakers to uncover component stresses and to determine if a product will pro duce ac line disturbances that interact with other equipment connected to the branch circuit For this example the equipment under test requires an ac line voltage of 120 Vrms at 60 Hz Agilent 6800 series features used RMS voltage and frequency control Peak current measurement e Pre event current data capture e Trigger synchronization to the output voltage phase e Measurement and waveform generation synchronization High crest factor Advantages benefits of the Agilent 6800 series solution The 6800 series provides a One Box Solution for measurement and waveform generation and elimi
32. pli cations The fully featured front panel and built in GPIB and RS 232 interfaces allow you to program waveforms measure parameters and monitor the status of the ac power source analyzer Each model features a SCPI Standard Commands for Programmable Instruments command set This industry standard command set simplifies test sys tem development by offering command set common ality between all types of instrumentation Instru ments performing the same function use the same self documenting SCPI instructions For example the same commands are used to program a wave shape on the 6800 series ac power source analyzers as on a function generator Because you spend less time learning device commands you can get your application up and running faster The following sections of this product note explain how to optimize your usage of the features of the 6800 series products At the end of this product note there are practical examples that show how these features can be applied Agilent 6800 Series Output Transients A programmable output value of the ac power source analyzer can operate in one of four modes FIXED Step Pulse or List The default setting is FIXED mode where the output will stay fixed at the programmed value until another command is sent to change it The remaining three operating modes constitute the Transient Subsystem Output transients are used to e synchronize output changes with a particular phase of
33. receipt of the trigger the ac source continues to output a 120 Vrms 60 Hz sinewave for 5 seconds After the 5 second trigger delay the rms voltage drops to 0 Vrms at 80 of the cycle and then rises back to 120 Vrms 0 001389 seconds later at 110 of the cycle Variations on this implementation 1 The Pulse width can be increased to simulate full cycle dropouts 2 The Pulse count can be set to a value gt 1 and the Pulse period can be programmed to 0 01667 seconds the period of a 60 Hz sinewave to create multiple dropouts 120 Viens 0 Yms internal Phase Sync sv Signal i Trigger Delay 5 second delay Bus Trigger 3 The triggered level of the rms voltage can be set higher than the initial setting of 120 Vrms to simulate a voltage surge 4 The rms voltage slew rate can be programmed in Pulse mode to simulate a gradual brown out sag condition versus an abrupt dropout The Pulse width can be increased to simulate a sag over multiple ac line cycles Timing Diagram of Application 1 Program for Application 1 Simulating AC Line Sub cycle Dropouts Program APP_1 BAS DECLARE SUB ADDRESS DECLARE SUB COMMAND ADDR CMD ACS 5 CALL ADDRESS CALL COMMAND ACS RST CALL COMMAND ACS VOLT 120 CALL COMMAND ACS CURRENT PEAK MAX CALL COMMAND ACS VOLT MODE PULSE CALL COMMAND ACS VOLT TRIGGERED 0 CALL COMMAND ACS PULSE WID
34. st the output will return to the immediate settings Agilent 6800 series setup e Connect the ac source output to the ac input of the equipment under test Set the rms voltage to 115 Vrms Set the frequency to 400 Hz Set the rms voltage to List mode Set the rms voltage slew to List mode Set the frequency to List mode Set the List to sequence automatically Agilent 6800 series setup continued Set the List points as follows List Vrms Dwell Point Vrms frequency Slew Time 1 115 V 400 Hz INF 60s 2 127 V 400 Hz INF 0 01 s 3 88 V 400 Hz 566 V s 0 07 s 4 115V 400 Hz INF 60 s 5 57 V 400 Hz INF 0 01 s 6 76 V 400 Hz 283 V s 0 07 s 7 115V 400 Hz INF 60 s 8 115V 425 Hz INF 1s 9 115V 420 Hz INF 4s 10 115V 410 Hz INF 5s 11 115V 407 Hz INF 4s 12 115V 400 Hz INF 60 s 13 115V 375 Hz INF 1s 14 115V 380 Hz INF 4s 15 115V 390 Hz INF 5s 16 115V 393 Hz INF 4s 17 115V 400 Hz INF 60 s List points 1 4 7 12 and 17 represent periods of time when the ac input to the equipment under test is set to the nominal levels prior to the onset of the next transient The length of time the output of the ac power source analyzer is set to the nominal level can be determined by user convenience 60 seconds for this example Set the transient trigger source to BUS e Initiate the transient trigger e Enable the output of the ac power source analyzer Send a bus tr
35. the voltage waveform e synchronize output changes with trigger signals e simulate ac line disturbances with precise dura tion and phase control e create sequences of output changes Output transients are triggered actions and will cause the output of the ac power source analyzer to react in a manner defined by the selected mode What Programmable Functions can be Controlled by the Transient Subsystem The 6800 series provides control of many output parameters Most of these can be programmed as an output transient The following output parame ters are subject to transient control e ac output voltage e dc output voltage Agilent 6812A and 6813A only e frequency e phase Agilent 6834A only e waveform shape e ac voltage slew rate e dc voltage slew rate 6812A and 6813A only e frequency slew rate e peak current limit 6812A and 6813A only rms current limit e dwell time List mode only Upon receipt of a trigger an output parameter set to Step Pulse or List mode will transition from an immediate level its initial output setting to one or more levels successive output settings The num ber of successive output settings is in part what differentiates one transient mode from another What is a STEP Transient A Step transient generates a single triggered out put change from an immediate output level to ONE successive output level of one or more of the output parameters subject to transient control Only o
36. to operate in the List transient mode Set the List to be dwell time paced Set the rms voltage frequency frequency slew rate and dwell time values Vrms LIST VOLT 115 127 88 115 57 76 115 115 115 115 115 115 115 115 115 115 115 CALL COMMAND ACS Vrms Freq LIST FREQ 400 400 400 400 400 400 400 425 420 410 407 400 375 380 390 393 400 CALL COMMAND ACS Freq Vslew LIST VOLT SLEW MAX MAX 566 MAX MAX 283 MAX MAX MAX MAX MAX MAX MAX MAX MAX MAX M AX CALL COMMAND ACS Vslew Dwell LIST DWELL 60 0 01 0 07 60 0 01 0 07 60 1 4 5 4 60 1 4 5 4 60 CALL COMMAND ACS Dwell gt CALL COMMAND ACS TRIGGER SOURCE BUS CALL COMMAND ACS INITIATE SEQI CALL COMMAND ACS OUTPUT ON CALL COMMAND ACS TRG END Subroutines SUB ADDRESS OPEN GPIBO FOR OUTPUT AS 1 OPEN GPIBO FOR INPUT AS 2 PRINT 1 ABORT PRINT 1 GPIBEOS IN LF END SUB SUB COMMAND ADDR CMDS C OUTPUT STRS ADDR CMDS PRINT 1 C END SUB Set the GPIB as the transient trigger source Tnitiate the transient trigger Turn on the ac source output Send the bus trigger Application 3 Performing IEC 555 2 Measurements Overview of application IEC 555 2 1982 is a regulatory standard that pertains to ac line disturbances namely current harmonics These current harmonics are caused by connecting household appliances and similar elec trical equipment to a 230 V 50 Hz ac
37. uare waveforms and can be used in all modes where the FUNCtion SHAPe command is valid Implementation details How the 6800 series implements user defined waveforms The computer is used to generate an array of 1024 voltage amplitude points that represent one cycle of the 77A Secretariat 101 Class 1 wave form This data is sent to the ac source as a named CLASS 1 user defined waveform and is stored in a non volatile memory location The List mode of the ac power source analyzer is used to sequence through the appropriate output settings at 2 minute intervals as per the draft The programmed param eters for each List point are shape waveform and dwell time The rms voltage and frequency output settings remain in Fixed mode The first List point is the fundamental waveform 120 Vrms sinewave at 60 Hz and will be output upon receipt of a tran sient trigger for 2 minutes The CLASS 1 waveform will be output for 2 minutes as part of the second List point After this 2 minute test the fundamen tal waveform will be output again as part of the final List point Agilent 6800 series setup the equipment under test storage space Set the Shape to List mode Set the List points as follows Connect the ac source output to the ac input of Use the computer to develop a 1024 point array representing a cycle of voltage amplitude data Use the TRACe DEFine command to name the waveform CLASS 1 and allocate non volatile Use the TRACe
38. utput parameters programmed to Step mode will be part of the triggered action The output will remain at the final output level once the Step transient is complete What is a PULSE Transient A Pulse transient generates a triggered output change that returns to its immediate output level after a programmed time period A Pulse transient can also be programmed to repeat the output change more than once or continuously What is a LIST Transient A List transient generates a sequence of output changes Each output change of the sequence is called a List point All parameters subject to tran sient control can be programmed at each List point A List can contain up to one hundred points The list of points can be programmed to execute once or to repeat from one to an infinite number of times Agilent s 6800 series List points can be paced by external triggers When paced by triggers the out put will remain at a particular List point until a trigger is received Only then will it proceed to the next programmed point List points can also be paced by individual pro grammable dwell time parameters associated with every point Only when the dwell time for a partic ular List point expires will it proceed to the next List point Once the List is completed the output returns to the immediate levels IMMediate level mmm FlXed mode TRiGgered level IMMediate level mug STEP mode TRiGgered level iMMediate level PUL
39. veform with harmonic volt age content as defined by the IEC 77A Secretariat 101 draft dated 10 15 93 will be created stored and generated by the ac power source analyzer Harmonic Voltage Levels for 120 Vrms Harmonic Number Class 1 Class 2 3 9 6 V 7 2 V 5 10 8 V 9 6 V 7 6V 8 4 V 11 2 4 V 8 4 V 13 2 4 V 7 2 V The equipment under test used for this example has an ac input rating of 120 Vrms 60 Hz and 5 Arms The waveform generated will comply with the Class 1 harmonic combination as currently proposed shown above This draft specifies that the equipment under test must be subjected to the harmonic waveform of either Class for 2 min utes succeeded by 2 minutes of the fundamental 120 Vrms sinewave waveform 24 Agilent 6800 series features used e Non volatile user defined arbitrary waveform creation storage e rms voltage programming Frequency programming e Waveform shape transient generation List transient mode Advantages benefits of the Agilent 6800 series solution The user defined waveform is stored in non volatile memory eliminating the need for con stant re creation and making it easy to recall the waveform as the test is needed A List of out put waveforms can be generated by combining built in and user defined waveforms simplifying complex test sequences The user defined wave form can be recalled as if it was one of the stan dard output shapes such as sine and sq
40. view of application The ability of a switching power supply to main tain its output voltage setting in the presence of typical ac line disturbances is critical to its end use If the end use of the power supply is installa tion into a computer for example sensitivity to ac line variations can result in unexpected loss of critical data and system downtime To simulate these common ac line voltage variations an ampli tude controlled ac voltage can be applied to the ac input of the power supply For this example the power supply requires a single phase ac source set to a nominal line voltage of 120 Vrms and frequency of 60 Hz To test the power supply under worst case conditions a volt age dropout to 0 Vrms should occur between 80 and 110 i e a duration of 0 001389 seconds on the voltage waveform This is a steadystate test which means that the dropout occurs after the ac input of the power supply under test has settled from all non repetitive inrush conditions that typically occur at power up Agilent 6800 series features used RMS voltage in Pulse mode e Trigger synchronization to the output voltage phase e Trigger delay Advantages benefits of the Agilent 6800 series solution By using the trigger phase synchronization capability the timing of the dropout is accurate and repeatable By using the transient capability the computer is not devoted to sequencing the output By using the trigger delay it
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