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1. Sense Input 4 Wire 2 Wh CURRENT SOURCE SS FOR GUARDED MEASUREMENTS ONLY 411 term 1008vpk Hox or 34560PC F 3 5 Figure 12 Current measurement connections Resistance The multimeter measures resistance by supplying a known current through the unknown resistance being measured The current passing through the resistance generates a voltage across it The multimeter measures this voltage and calculates the unknown resistance resistance voltage current Table 14 shows each 2 and 4 wire ohms range and its full scale reading the full scale reading also shows the maximum number of digits for each range Table 14 also shows the maximum resolution and current sourced for each range Resolution is a function of the specified integration time refer to Setting the Integration Time later in this section for more information Table 14 Resistance Ranges OHM F Range Full Scale Reading Maximum Resolution Current Sourced 10Q 12 00000Q 10nQ 10mA 100Q 120 00000Q 10yQ 1mA 1kQ 1 2000000kQ 100uQ 1mA 10kQ 12 000000kQ 1mQ l00uA 100kQ 120 00000kQ 10mQ 50yuA 1MQ 1 2000000MQ 100mQ 5yA 56 Chapter 3 Configuring for Measurements Table 14 Resistance Ranges OHM F Range Full Scale Reading Maximum Resolution Current Sourced 10MQ 12 000000MQ 10 500nA 100MQ 120 00000MQ 10Q 500nA 1GQ 1 2000000GQ 100Q 500nA 2 Wire Ohms Two wire ohms is most c
2. 104 Triggering Setup oo ec cecseeceeetecseeneeeees 105 Delay Time 0 ccceccccsecsteeseceeeceteeeseeeeenaaes 105 AC Bandwidth 20 ceececeseeeeeeceteeeeeseees 105 Offset Compensation ccccccesseeseeteeees 105 High Speed DCV Example eeeeee 105 High Speed OHM or OHMF Example 105 High Speed DCI Example eee 106 Fast Synchronous ACV ACDCV Example 106 Fast Random ACV ACDCV Example 106 Fast Analog ACV ACDCV Example 106 Fast ACI ACDCI Example 0 0 0 107 Fast FREQ or PER Example 107 High Speed Transfer across GPIB 0 107 High Speed Transfer from Memory 108 Determining the Reading Rate ee 109 The EXTOUT Signal cc cccecceceeseeteesteeseeens 110 Reading Complete cccccccssecsseesteeteeeteeees 112 Burst Complete cccccccceesccesseecseeteeteenteees 113 Input Complete cccceccessceeseesseeseeteeeteeees 114 Aperture Waveform 0 ccceccceseeseersenteesseens 114 Service Request cccceeccesseeseeseeeteceteeeeeesees 114 EXTOUT ONCE viaaa s 115 Math Operations 0 ccceccecssecseceteceteeeeeeeseesseesseens 116 Real Time vs Post Process eecesceeeereeeees 116 Enabling Math Operations ceeeeereeeee 116 Math Registers ccccccesceesseesecseceteceneeeeeeeees 117 NUL eead ne a ernie ook 117 SCALE pennen aaee i AR E tens ont 119 Pere nt ii tevsececet ceseceacceseaa tevedens
3. ccccecsecsteeeteeteeeteeeseeenes 267 Using Variables ccceccecsceeseescceeseceteeeteeeeeeees 267 ATLAVS arrenar e SE S 268 General Purpose Math 0 cceceeecceeseeeesteeeeeeeees 269 Math Operators ceccesccesseeseeesecsteeeteeeeeeees 270 Math Hierarchy 0 cccescecceeseeeseeeteeeteeeeees 272 Math Errors eseeseecceececeeeeeeeceseeseeseeeeeeeeeaeeas 272 Making Comparisons Work eeceeeeees 272 Subprograms 00 eeccecceeseeesseesseeseceteceeeeeeeseeeeeeaees 273 Writing and Loading Subprograms ee 274 Subprogram Command Types ccceccceseereees 275 Definition Deletion Commands 05 275 Execution Commands sceecceseseereeeeeeeees 277 Conditional Statements in Subprograms 278 FOR NEXT Loops 0 cecccesseeeseeeeteeeeeeeeees 278 WHILE LOOPS ccisseccasccccsstssvvessocaaents savescaasneoancs 279 IF THEN Branching 0 cc cceceeseesteeteeees 280 Appendix A Specifications Appendix B GPIB Commands Introduction cc ciecccccccssccceesssccsessscecessscecessseeeees 303 ABORT 7 IFC ccccceccessceseeceecsecsseesseeeeens 304 CLEAR DCL or SDC wo cecceceeeceseeeseereenees 304 LOCAL GTE rereana een aR 304 LOCAL LOCKOUT LLO sssssssssssssesseeee 305 REMOTE ue ceccccccccecsscseccecessecsssessssesssesseeeees 305 SPOLL Serial Poll oo cece cececeeseeeseeees 306 TRIGGER GET cccccccccecsccsseeseeesseesseeecees 307
4. cccccscesscssceceeseeeeeeseessees 74 Deleting States sicist ceceeashccceedhs eoictedadeevinceses sone 75 Using the Input Buffer eecceeeteerteeeees 75 Using the Status Register eeeceeseeeteesteeeees 75 Reading the Status Register cece 77 IMO TTUPts eroaren n iach evs daceanetvacesets dads 77 Chapter 3 Configuring for Measurements 45 46 Chapter 3 Configuring for Measurements Chapter 3 Configuring for Measurements Introduction This chapter shows how to configure the multimeter for all types of measurements except digitizing This chapter also shows you how to use subprogram and state memory the input buffer and the status register After using this chapter to configure the multimeter for your application you can then use Chapter 4 to learn how to trigger readings and transfer them to reading memory or the GBIB output buffer The major sections in this chapter are e General Configuration e Configuring for DC or Resistance Measurements e Configuring for AC Measurements e Configuring for Ratio Measurements e Using Subprogram Memory e Using State Memory Using the Input Buffer Using the Status Register General Configuration Self Test This section discusses the multimeter s self test calibration requirements and general configuration topics that apply to many or all measurement functions Prior to configuring for measurements you should run the self test to ensure t
5. 310 L L Inc 320 NEXT J 330 NEXT I 340 FOR I N1 1 TO N1 N2 350 L I 360 FOR J 1 TO N3 1 370 Wave_form L Samp K 380 K K 1 390 L Lt Inc 400 NEXT J 410 NEXT I 420 END SSPARM Sub Sampling Parameters Query Returns the parameters necessary to reconstruct a sub sampled waveform SSAC or SSDC command when the samples are sent directly to the GPIB output buffer Reconstruction is automatic when the samples are sent directly to reading memory The first parameter returned by SSPARM is the number of bursts that contained N samples The second parameter is the number of bursts that contained N samples The third parameter returned is the value of N For example assume you are sub sampling a 10kHz signal and specify 22 samples with an effective_interval of Sus In this example the multimeter must use a total of 4 bursts 2 bursts contain 6 samples each and 2 bursts contain 5 samples each The values returned by SSPARM are then 2 2 and 6 Syntax SSPARM Remarks Related Commands SSAC SSDC SSRC SWEEP Example See the SSDC example on the preceding page SSRC Sync Source For sub sampling SSAC or SSDC command the SSRC 240 Chapter 6 Command Reference Syntax SSRC command allows you to synchronize bursts to an external signal or to a voltage level on the input signal For synchronous ACV or ACDCV SETACV SYNC command the SSRC command allows you to synchronize sampling to an external signal
6. 32767 through 32767 The DIM command declares real arrays The INTEGER command declares integer variables or arrays The REAL command declares real variables or arrays The following program statement declares real array A with 10 elements numbered 0 through 9 OUTPUT 722 DIM A 9 The following program statement declares integer array IARRAY with 10 elements numbered 0 through 9 and integer variable B OUTPUT 722 INTEGER IARRAY 9 B The following program statement declares real array RARRAY with 10 elements numbered 0 through 9 with real variable C OUTPUT 722 REAL RARRAY 9 c The 3458A declares variables automatically when a variable name appears Chapter 7 BASIC Language for the 3458A Note Type Conversions Using Variables in an assignment statement with the LET command For example the following statements automatically declare the variable names specified OUTPUT 722 LET A SIN 223 OUTPUT 722 LET B 3 14159 Some 3458A commands expect a specific variable type when defining variables for parameters For example the TIME command expects a real number Similarly commands which return numeric results will return specific number types The LINE command returns an integer number Measurements returned are real numbers All variables are REAL unless otherwise specified PROGRAMMING HINT Once you declare an array type you cannot re declare it as a different type without scratching mem
7. QFORMAT ALPHA 20 OUTPUT 722 ARANGE 30 ENTER 722 AS 40 PRINT AS 50 END Typical response ARANGE ON R is an abbreviation for the RANGE command R max _input _resolution Refer to the RANGE command for more information The RANGE command allows you to select ameasurement range or the autorange mode RANGE max _input _resolution max _input The max _input parameter selects a fixed range or the autorange mode To select a fixed range you specify the max input as the absolute value no negative numbers of the maximum expected amplitude of the input signal The multimeter then selects the correct range To select the autorange mode specify AUTO for max input or default the parameter In the autorange mode the multimeter samples the input signal before each reading and selects the appropriate range The following tables show the max _input parameters and the ranges they select for each measurement function Chapter 6 Command Reference 221 RANGE 222 For DCV max _input Selects Full Parameter Range Scale 1 or AUTO Autorange 0 to 12 100mV 120mV gt 12 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to 1E3 1000V 1050V For ACV or ACDCV max _input Selects Full Parameter Range Scale 1 or AUTO Autorange 0 to 012 10mV 12mV gt 012 to 12 100mV 120mV gt 12 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to 1E3 1000V 1050V Fo
8. IEEE 488 Interface Complies with the following IEEE 488 1 Interface Standard IEEE 728 Codes Formats Standard CIIL Option 700 Included with Keysight 3458A Test Lead Set Keysight 34118A Power Cord User s Guide Calibration Manual Assembly Level Repair Manual Quick Reference Guide Keysight Part Number 03458 87901 03458 80002 03458 84303 Available Documentation Keysight Part Number Product Note 3458A 1 Optimizing Throughput and Reading Rate Product Note 3458A 2 High Resolution Digitizing with the 3458A Product Note 3458A 3 Electronic Calibration of the 3458A Extra Manual Set 5953 7058 5953 7059 5953 7060 03458 90000 Appendix A Specifications 299 300 Appendix A Specifications Appendix B GPIB Commands Introduction ecra aa e 303 ABORT 7 FO iiii eis a ERS 304 CLEAR DCL or SDC wo ecccceeeeeceeseeseenees 304 LOCALE GTL aieh ennaa 304 LOCAL LOCKOUT LLO ssesssssssseesseeese 305 REMOTE a ee aa EE 305 SPOLL Serial Poll oc eccccceceeseeeseeees 306 TRIGGER GET cccccccccecsecsseesecesseesseeeeees 307 Appendix B GPIB Commands 301 302 Appendix B GPIB Commands Appendix B Introduction GPIB Commands Introduction The BASIC language GPIB commands in this appendix are specifically for HP Series 200 300 computers Any IEEE 488 controller can send these messages however the syntax may be different from that shown here The IEEE 488 terminology is shown in pare
9. a pi J W W Appendix D Optimizing Throughout and Reading Rate 341 342 680 690 700 710 720 730 740 750 760 770 780 790 800 810 820 830 840 850 860 870 880 890 900 910 920 930 940 950 960 970 980 990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 10 20 30 40 50 60 70 80 90 2200 2210 2220 2230 2240 2250 2260 2270 2280 2290 2300 2310 2320 NONMNNNNNN NY N Z a 4 ti R 722 A 27 UTPUT 722 DCV 10 NPLC 0 DELAY 0 28 TO 33 R 722 A I ZO iW pi j Lam 3 4 as UT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY 01 NTER 722 A 34 UTPUT 722 DCV 10 NPLC 0 DELAY 0 35 TO 37 NTER 722 A 1 NEXT Exe_tlme TIMEDATE Exe_time Dnld_time 0 Tns_time 0 SUBEND SUB Burst REAL Dnld_time Exe_time Tns_time DIM A 37 Exe time TIMEDATE OUTPUT 722 PRESET MEM FIFO MFORMAT SREAL OUTPUT 722 OHM 1E4 NPLC 0 DELAY 0 NRDGS 15 TRIG SGL OUTPUT 722 0HM 1E5 NRDGS 8 TRIG SGL O O O O O O H HowNo z y ot a t w x H UTPUT 722 OHMF 1ES APER 20E 6 DELAY 1 NRDGS 2 TRIG SGL UTPUT 722 ACV 250 ACBAND 250 DELAY 1 NRDGS 1 TRIG SGL UTPUT 722 ACV 10 ACBAND 25000 DELAY 01 TRIG SGL UTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 6 TRIG SGL UTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY 01 NRDGS 1 TRIG SGL UTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 3 TRIG SGL Exe_time TIMEDATE Exe_time Dnld_time 0 Tns_time TIMEDA
10. Using the Input Buffer cece eeeeeeeeeeeeeees 75 Using the Status Register cccecceseeseceteeteeeees 75 Reading the Status Register 0 0 0 eseeeeeeees 77 INTErraptS irrena ia aaia a 77 Chapter 4 Making Measurements IMtFOdUCHON i352 ihe pion ea isis Ghai annealed 81 Triggering Measurement esceceeeeeceeeeeeeees 81 The Trigger Arm Event sesers 82 The Trigger Event ccceccccsecsteeeeeeeeteetsees 82 The Sample Event ccceccccsecsseceteeeteeereeesees 82 VME Choices je tier ieasade shed cian apa cunudass 82 Making Continuous Readings ceseeeee 82 Making Single Readings eeeeseeeeeeeeeeee 83 Making Multiple Readings 00 0 0 ceeeeeeeseeeees 83 Multiple Trigger Arming sesers 84 Making Synchronous Readings eeeeee 84 Making Timed Readings eecceseereeeeeeeeee 85 Making Delayed Readings 0 eeeceeeeeereeeee 86 External Triggering 0 0 ceeeeeeeseeeeceeeeeeeeeees 87 Event Combinations cccecceeseeseeteeseeeeeenees 88 Reading Formats ccccccsccesssesseeseeeseceteceteeseeeenes 92 ASCU e A A freer tener ore treo 92 Single and Double Integer 0 0 0 ei eeeeeeeeeeeee 92 Single Real oo ccecccecseesseesseeeeeeeteeeeeeeeeesseeseeens 93 Using Reading Memory cccecccssecseceteeeteeeeeeees 94 Memory Formats c ccccccecsseeeeteceeseeceeeeeaes 95 Recalling Readings n se 96 Sending Readings Across the Bus eeeeeeee 9
11. When the multimeter is displaying readings you can vary the number of digits it displays In the power on state the display is showing 7 5 digits although the multimeter is resolving 8 5 digits To display all 8 5 digits press N ene gt 8 Comp Q Enter The display s leftmost digit referred to as a 1 2 digit is implied when you are specifying display digits The NDIG command only masks digits from the display It does not affect readings sent to reading memory or transferred over the GPIB bus Also you cannot view more digits than are being resolved by the multimeter You can easily recall the last executed command without repeating the command entry process Press Recall a The display will show the last command executed You cannot recall commands that are executed immediately such as Reset or DCV or any command that contained the calibration security code By repeating the above keystrokes you can recall previously executed commands After recalling the desired command you can modify it see Display Editing earlier in this section and execute it by pressing Enter Chapter 2 Getting Started 39 User Defined Keys You can assign a string of one or more commands to each of the USER keys 40 Chapter 2 Getting Started labeled f0 f9 After assigning a string to one of these keys maximum string length is 40 characters pressing that key displays the string on the display Y
12. 10 but cannot exceed 250 VAC RMS Maximum power consumption is 80 VA Volt Amps The nominal line voltage values and their corresponding limits are shown in Table 3 Possible multimeter damage Before connecting the multimeter to an AC power source verify that the multimeter s line voltage selection switches are set to match the AC line voltage and that the proper line fuse is installed These topics are discussed in the following sections Chapter 1 Installation and Maintenance 17 Table 3 Line Voltage Limits Nominal Value RMS Allowable Limits RMS _ T00 VAC 90 VAC to 170 VAC 120 VAC 108 VAC to 132 VAC 220 VAC 198 VAC to 242 VAC 240 VAC 216 VAC to 250 VAC Setti ng the Line The line voltage selection is pre configured according to the country to which Volta ge Switches it is shipped Use the following procedure if you need to change this setting 1 Remove the multimeter s line power cord before changing the positions of the AC line voltage selection switches 2 With a small flat blade screwdriver move the switches to the appropriate positions as shown in Figure 2 3 Install the correct line power fuse as described in the next section 120 120 240 240 220 220 400 100 100 VAC 120 VAC 120 120 240 240 100 100 220 VAC 240 VAC Figure 2 AC line voltage switch positions Installing the Line The line power fuse must match the line voltage selection For 100 VAC or Power Fuse 120 VAC opera
13. 30 OUTPUT 722 TRIG SGL TRIGGERS ONCE 40 OUTPUT 722 SMATH RES PLACES READING IN RES REGISTER 50 DISP CONNECT SOURCE PRESS CONT OPERATOR PROMPT 60 PAUSE SUSPENDS PROGRAM EXECUTION 70 OUTPUT 722 ACV SELECTS AC VOLTAGE 80 OUTPUT 722 MATH DBM ENABLES DBM MATH OPERATION 90 OUTPUT 722 TRIG AUTO TRIGGERS AUTOMATICALLY 100 END SRQ 236 Syntax Example Service Request Sets bit 2 in the multimeter s status register If bit 2 is enabled to assert SRQ RQS 4 command executing the SRQ command will set the GPIB SRQ line SRQ Related Commands CSB EXTOUT RQS SPOLL GPIB command STB 10 OUTPUT 722 RQS 4 ENABLE STATUS REGISTER BIT 2 TO ASSERT SRQ 20 OUTPUT 722 SRO SET BIT 2 ASSERT SRO 30 END Chapter 6 Command Reference SSAC SSDC Syntax Remarks SSAC SSDC Sub Sampling Configures the multimeter for sub sampled voltage measurements digitizing The SSAC function measures only the AC component of the input waveform The SSDC function measures the combined AC and DC components of the waveform Otherwise the two functions are identical The input signal must be periodic repetitive for sub sampled measurements Sub sampled measurements use the track hold circuit 2 nanoseconds aperture and a wide bandwidth input path 12 MHz bandwidth SSAC max _input resolution SSDC max _input _resolution max _input Selects the measurement range you cannot use autorange fo
14. 70 Samp I J 65536 K 65536 K lt 0 CONVERT TO REAL NUMBER 80 R ABS Samp I USE ABSOLUTE VALUE TO CHECK FOR OVLD 90 IF R gt 2147483647 THEN PRINT OVLD IF OVERLOAD OCCURRED PRINT MESSAGE 200 Samp I Samp I S APPLY SCALE FACTOR 210 Samp 1I DROUND Samp I 8 ROUND CONVERTED READING 220 PRINT Samp I PRINT READINGS 230NEXT I 240END Sub Sampling In sub sampling also known as sequential sampling the multimeter takes one or more samples on each period of the input signal With each successive period the beginning sample point is delayed further and more samples are taken After a number of periods have occurred and the specified number of samples have been taken the samples can be reconstructed to form a Chapter 5 Digitizing 139 140 Sub Sampling Fundamentals Chapter 5 Digitizing composite waveform with a period equal to that of the input signal The advantage of sub sampling is that samples can be effectively spaced at a minimum interval of 10ns versus 10us for DCV digitizing and 20us for direct sampling This means that sub sampling can be used to digitize signals with frequency components up to 12 MHz the upper bandwidth of the signal path for sub sampling Sub sampled measurements use the track and hold circuit which has a 2 nanosecond aperture Sub sampling and direct sampling have less trigger jitter than DCV digitizing see the Specifications in Appendix A The disadvantages of sub samp
15. EXTOUT ICOMP POS Aperture Waveform EXTOUT APER NEG EXTOUT APER POS Reading Complete Reading 1 Complete Reading 2 Complete Reading 3 Complete A D Busy v A D Busy v A D Busy v Integrate J Integrate d integrate Figure 20 A D Converter event relationships When specified the reading complete event RCOMP event produces a 1 us pulse following each reading for any measurement function For sampled AC voltage measurements SETACV SYNC or RNDM a pulse is output after each computed reading not after each sample in the measurement process This event can be used to synchronize an external scanner to the multimeter when making one reading per scanner channel The following program uses the RCOMP event to synchronize the multimeter to a scanner the example uses a 3235 Switch Test Unit with a scanning module in slot 200 Measurement connections are shown in Figure 21 The scanner is programmed to output a low going pulse after each channel closure line 60 This pulse is connected to the multimeter s Ext Trig connector and triggers each reading After each reading the multimeter s EXTOUT signal causes the scanner to advance to the next channel The channel closure generates a signal which in turn triggers the next reading This sequence repeats until all 6 channels have been scanned Readings are stored in the multimeter s reading memory Chapter 4 Making Measurements 10 OUTPUT 722 PRESET NORM DCV NRDGS 1
16. Each of the front and rear current terminals labeled I contains a current fuse To access the fuse unscrew rotate counterclockwise the current terminal binding post knob until it stops Push in on the terminal and rotate it clockwise The entire terminal fuse assembly can now be removed as shown in Figure 5 Ifnecessary replace the fuse with a 1A 250V NTD fuse Keysight part number 2110 0001 CAUTION never use a slow blow fuse as a current fuse multimeter damage will result Replace the terminal fuse assembly by pushing it in and turning counterclockwise until the assembly locks in place Chapter 1 Installation and Maintenance 21 Figure 5 Current Terminal Fuse Assembly Re pair Service You may have the multimeter repaired at a Keysight Technologies service center whether it is under warranty or not Contact the nearest Keysight Sales Office for shipping instructions prior to returning the instrument Serial Number Keysight instruments are identified by a two part ten character serial number of the form 0000A00000 The first four digits are the same for all identical products They change only when a change is made to the product The letter indicates the country of origin An A indicates the product was made in the United States of America The last five digits are unique to each instrument The multimeter s serial number is located to the right of the multimeter s rear terminals Shipping Instructions Ifyou need to ship the mu
17. There are a number of commands in the alphabetic command directory that end with a question mark These commands are called query commands since each returns a response to a particular question For example access the LINE query command from the command menu and press the Enter key The multimeter responds to this query command by measuring and displaying the power line frequency Use the right arrow key to view the entire response As another example access the TEMP command from the command menu and press Enter This command returns the multimeter s internal temperature in degrees Centigrade The FULL command menu contains the following standard query commands AUXERR MCOUNT CAL MSIZE CALNUM OPT ERR REV ERRSTR SSPARM ID STB ISCALE TEMP JINE In addition to the queries listed above you can create others by appending a question mark to any command that can be used to program the multimeter For example the AZERO command Auto Zero configuration key enables or disables the autozero function You can determine the present autozero mode by appending a question mark to the AZERO command To do this press Auto Store Zero State The multimeter responds by displaying the present autozero mode power on mode ON Notice that this command is immediately executed you do not have to press the Enter key The QFORMAT command can be used to specify whether query responses will be nume
18. 000030 000300 6 5 000366 1000 000305 1000 Specifying You can specify the measurement resolution as the last parameter Resolution _resolution parameter of a function command FUNC ACV ACI etc or the RANGE command For all analog AC voltage and current measurements resolution is specified as a percentage of the command s max _input parameter The multimeter multiplies the specified _resolution parameter times the max _input parameter to determine the measurement resolution To determine the value of the resolution parameter use the equation _ resolution actual resolution maximum input x 100 For example suppose your maximum expected input is 10 VAC and you need 1 mVAC of resolution The equation evaluates to _ resolution 0 001 10 x 100 0 01 For analog AC measurements resolution is determined by the A D converter s integration time When you specify a resolution you are actually indirectly specifying an integration time Since the NPLC command can also specify an integration time an interaction occurs when you specify resolution as follows e If you send the NPLC command before specifying resolution the multimeter satisfies the command that specifies greater resolution more integration time e Ifyou send the NPLC command after specifying resolution the multimeter uses the integration time specified by the NPLC command and the previously specified resolution is ignored 1
19. 012 to 120 100mV 120mV gt 120 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to IE3 1000V 1050V As with direct sampling you can specify a level triggering voltage up to 500 of the range The required SINT format however cannot handle samples greater then 120 of range If reading memory is disabled when you execute the SSAC or SSDC command the multimeter automatically sets the output format to SINT the memory format is not changed Later when you change to another measurement function the output format returns to that previously specified You must use the SINT output format when sub sampling and outputting samples directly to the GPIB You can however use any output format if the samples are first placed in reading memory see next remark To do this you should enable reading memory before executing the SSAC or SSDC command executing SSAC or SSDC does not change the output format to SINT when reading memory is enabled When sub sampling with reading memory is enabled reading memory must be in FIFO mode must be empty executing MEM FIFO clears reading memory and the memory format must be SINT prior to the occurrence of the trigger arm event If not the multimeter generates the SETTINGS CONFLICT error when the trigger arm event occurs and no samples are taken e When sub sampling an input signal with a frequency content gt 1 MHz the first sample may be in error because of inter
20. 30 OUTPUT 722 PRES 40 OUTPUT 722 MEM 50 OUTPUT 722 NRDG 60 OUTPUT 722 TARM 70 OUTPUT 722 EXTO 75 80 OUTPUT 722 O0COM 90 OUTPUT 722 OHM 100 OUTPUT 722 NRD 110 OUTPUT 722 TARM SGL 120 OUTPUT 722 SUBEND 130 OUTPUT 722 CAL 140END STORE SUBPROGRAM NAMED EXTONCE SIGNAL EXTERNAL EQUIPMENT TO SWITCH TO DC VOLTAGE FAST READINGS SIGNAL TARM SYN TRIG AUTO ENABLE READING MEMORY FIFO MODE 20 READINGS PE R TRIGGER TRIGGER 20 READINGS SIGNAL EXTERNAL EQUIPMENT TO SWITCH TO RESISTANCE MEASUREMENT ENABLE OFFSET 2 WIRE OHMS 1 40 READINGS PE COMPENSATION Q RANGE R TRIGGER TRIGGER 40 READINGS END OF SUBPROGRAM CALL SUBPROGRA Chapt M er 4 Making Measurements 115 Math Operations 116 Real Time vs Post Process Enabling Math Operations Each math operation performs a specific mathematical operation on each reading and or stores data on a series of readings The multimeter can perform the null scale percent dB dBm filter RMS or temperature related math operations on readings The statistics and pass fail math operations do not alter readings but store information pertaining to readings This section describes how to enable and disable math operations and discusses each math operation in detail Math operations can be performed real time or post process When a real time math operation is enabled the operation is performed on each reading immed
21. 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE 50 Rdgs I Rdgs I s MULTIPLY READING TIMES SCALE FACTOR 60 Rdgs I DROUND Rdgs I 4 ROUND TO 4 DIGITS 70 NEXT I 80 END DINT Example The following program is similar to the preceding program except that it takes 50 readings and transfers them to the computer using the DINT format 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_readings I J K DECLARE VARIABLES 188 Chapter 6 Command Reference LEVEL Syntax LEVEL 30 Num_readings 50 NUMBER OF READINGS 50 40 ALLOCATE REAL Rdgs 1 Num_readings CREATE ARRAY FOR READINGS 50 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 60 ASSIGN Buffer TO BUFFER 4 Num_readingsl ASSIGN BUFFER I O PATH NAME 70 OUTPUT Dvm PRESET NORM RANGE 10 OFORMAT DINT NRDGS Num_readings 75 TARM AUTO TRIG SYN DCV 10V RANGE DINT OUTPUT FORMAT NRDGS 50 AUTO 80 TRANSFER Dvm TO Buffer WAIT SYN EVENT TRANSFER READINGS 90 OUTPUT Dvm ISCALE QUERY SCALE FOR DINT 00 ENTER Dvm S ENTER SCALE FACTOR 10 FOR I 1 TO Num_readings 20 ENTER Buffer USING W W J K ENTER ONE 16 BIT 2 S COMPLEMENT 21 WORD INTO EACH VARIABLE J AND K STATEMENT TERMINATION NOT 25 REQUIRED W ENTER DATA AS 16 BIT 2 S COMPLEMENT INTEGER 30 Rdgs 1 J 65536 K 65536 K lt O CONVERT TO REAL NUMBER 40 R ABS Rdgs I USE ABSOLUTE VALUE TO CHECK FOR OVLD 50 IF R gt 2147483647 THEN PRINT OVLD IF OVERLOAD OCC
22. 40 END The following program uses the first parameter and the count parameter to return and display the readings numbered 12 through 17 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 6 DIMENSION ARRAY FOR 6 READINGS 30 OUTPUT 722 RMEM 12 6 RECALL 6 READINGS STARTING WITH 12 40 ENTER 722 Rdgs ENTER READINGS 50 PRINT Rdgs PRINT READINGS 60 END You can also use record numbers when recalling readings The multimeter assigns the lowest record number 1 to the most recent record and the highest number to the oldest record The following program returns the 3rd and 4th reading in record number 6 in this case readings numbered 53 and 54 respectively 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 2 DIMENSION ARRAY FOR READINGS 30 OUTPUT 722 RMEM 3 2 6 RECALL 3rd amp 4th READINGS FROM RECORD 6 40 ENTER 722 Rdgs ENTER READINGS 50 PRINT Rdgs PRINT READINGS 60 END When executing RMEM from the front panel after recalling a reading by reading number you can use the up or down arrow keys to scroll through the other readings in memory The RMEM command is the only way to retrieve stored readings from the front panel Using Implied Read When the controller requests data from the multimeter and its output buffer is empty with reading memory enabled a reading is removed from memory placed in the output buffer and transferred to the controller This is the i
23. 8 Power On a power on sequence has occurred Bit 4 weight 16 Ready for Instructions the multimeter has completed execution of any previous commands and is ready to accept more commands When using TRIG SGL or TARM SGL to initiate a group of readings with the input buffer off this bit can be used to monitor when all readings are complete Bit 5 weight 32 Error one or more errors have been logged in the error auxiliary register Refer to Reading the Error Registers earlier in this chapter for more information Note You can prevent any or all errors from setting the error bit in the status register using the EMASK command Refer to the EMASK command in Chapter 6 for more information Bit 6 weight 64 Service Request service is requested and the GPIB SRQ line is set true This bit will be set when any other bit of the status register is set and has been enabled to assert SRQ by the RQS command It is possible for bit 6 to be the only bit set such as when an error set a bit in the error register which in turn set bit 6 Later the error register was read 76 Chapter 3 Configuring for Measurements Reading the Status Register Interrupts which removed the error bit but left bit 6 set Bit 7 weight 128 Data Available a reading or query response is available in the output buffer The STB query command reads the status register and returns the weighted sum of all set bits The STB command does not clear t
24. 80 END RES Syntax Resolution Specifies reading resolution RES _resolution _resolution For frequency and period measurements the _resolution parameter specifies the digits of resolution and the gate time as shown below _resolution also affects the reading rate Refer to the Specifications in Appendix A for more information If you default the resolution parameter for frequency or period measurements the multimeter uses 00001 _resolution Selects Digits of Parameter Gate Time Resolutio n 00001 ls 7 0001 100ms 7 001 10ms 6 01 lms 5 1 100us 4 For sampled ACV or ACDCV random sampling SETACV RNDM has a fixed resolution of 4 5 digits that cannot be changed For synchronous sampling SETACV SYNC a _ resolution parameter of 0 001 7 5 digits 0 01 6 5 digits 0 1 5 5 digits and 1 4 5 digits For all other functions except DSAC DSDC SSAC and SSDC _resolution is ignored for these functions the multimeter multiplies resolution times the present measurement range 1 V 10V 100V etc to determine the resolution To compute the resolution parameter use the equation _resolution actual resolution range x 100 For example suppose you are measuring DC voltage on the 10V range and you want 100uV of resolution The equation evaluates to _resolution 0001 10 x 100 001 Power on resolution none At power on the resolution is determined by the NPLC command which pro
25. AUTO TARM AUTO TRIG SYN 20 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 30 OUTPUT 722 TRIG EXT TRIGGER EVENT EXTERNAL 40 OUTPUT 722 EXTOUT RCOMP NEG READING COMPLETE EXTOUT LOW GOING TTL 45 CONFIGURE EXTERNAL SCANNER 50 OUTPUT 709 SADV EXTIN ADVANCE SCANNER ON MULTIMETER S EXTOUT SIGNAL 60 OUTPUT 709 CHCLOSED EXT OUTPUT LOW GOING PULSE AFTER EACH CLOSURE 70 OUTPUT 709 SCAN 201 206 SCAN CHANNELS 01 06 ON SCANNER IN SLOT 200 TS AND ADVANCE TO CHANNEL 01 STARTING THE SCAN 80 END TO EXT TRIG IN FROM DEVICES UNDER TEST t EROM EXT TRIG OUT SCANNING MODULE M TO EXT TRIG FROM EXT OUT CONNECTOR 34580PC F 4 6 Figure 21 Using an external scanner Burst Com plete When specified the burst complete event BCOMP event produces a ps pulse following completion of a group of readings The number of readings in a group is specified by the NRDGS or SWEEP command The BCOMP event can be used to synchronize an external scanner to the multimeter when making multiple readings per scanner channel The following program is similar to the preceding program except that it uses the BCOMP event and makes 15 readings on each scanner channel Connections for this example are shown in Figure 21 10 OUTPUT 722 PRESET NORM DCV NRDGS 1 AUTO TARM AUTO TRIG SYN 20 OUTPUT 722 MEM FIFO ENABLE READING ME
26. CONVERT READING FROM SREAL 80 Rdgs I DROUND Rdgs I 7 ROUND READING TO 7 DIGITS YOU 81 MUST DO THIS WITH SREAL TO ENSURE ANY OVLD VALUES ARE ROUNDED TO 85 1 E 38 WITHOUT ROUNDING THE VALUE MAY BE SLIGHTLY LESS 90 IF ABS Rdgs I 1 E 38 THEN IF OVERLOAD OCCURRED 200 PRINT Overload Occurred PRINT OVERLOAD MESSAGE 210 ELSE IF NO OVERLOAD OCCURRED 220 PRINT Rdgs I PRINT READING 230 END IF 240 NEXT I 250 END DREAL Format The following program uses the DREAL output format Notice that no conversion is necessary using this format since DREAL is the same format that the controller uses as its internal data format 8 bytes word 10 20 30 40 50 59 60 70 80 90 00 10 20 30 40 50 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 REAL Rdgs 1 10 BUFFER CREATE BUFFER ARRAY ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS ASSIGN Rdgs TO BUFFER Rdgs ASSIGN BUFFER I O PATH NAME OUTPUT Dvm PRESET NORM NPLC 10 OFORMAT DREAL NRDGS 10 TRIG SYN 10 PLCs DCV AUTORANGE DREAL OUTPUT FORMAT 10 RDGS TRIG TRANSFER Dvm TO Rdgs WAIT SYN EVENT TRANSFER READINGS FOR I 1 TO 10 IF ABS Rdgs I 1 E 38 THEN IF OVERLOAD OCCURRED PRINT OVERLOAD OCCURRED PRINT OVERLOAD MESSAGE ELSE IF NO OVERLOAD Rdgs I DROUND Rdgs I 8 ROUND READINGS RINT Rdgs I PRINT READINGS Chapter 6 Command Reference 213 OHM OHMF The preceding program used the TRANSFER statement to get readings
27. DC 60 Hz Temperature Coefficients Range Full Scale Maximum Input Impedance of Reading of Range C Resolution 10mV_ 12 000 l uV 1 MQ 15 with lt 140 pF 0 002 0 02 100mV_ 120 00 10 uV 1 MQ 15 with lt 140 pF 0 001 0 0001 1V 1 2000 100 pV 1 MQ 15 with lt 140 pF 0 001 0 0001 10 V 12 000 1 mV 1 MQ 2 with lt 140 pF 0 001 0 0001 100 V 120 00 10 mV 1 MQ 2 with lt 140 pF 0 0015 0 0001 1000 V 700 0 100 mV 1 MQ 2 with lt 140 pF 0 001 0 0001 AC Accuracy 3 24 Hour to 2 Year of Reading of Range ACBAND lt 2 MHz ACBAND gt 2 MHz 20 Hz 100 kHz 300kHz 1 MHz 20 Hz 100 kHz 1MHz 4MHz 8 MHz Range to 100 kHz to to to to to to to to 300 kHz 1MHz 2MHz 100 kHz 1 MHz 4MHz 8 MHz 10MHz 10 mV 0 5 0 02 4 0 02 0 1 0 05 1 2 0 05 7 0 07 20 0 08 100 mV 10 V 0 08 0 002 0 3 0 01 1 0 01 1 5 0 01 0 1 0 05 2 0 05 4 0 07 4 0 08 15 0 1 100 V 0 12 0 002 0 4 0 01 1 5 0 01 0 12 0 002 1000 V 0 3 0 01 0 3 0 01 Appendix A Specifications For DELAY 1 ARANGE OFF For DELAY 0 NPLC 1 unspecified reading rates of greater than 500 Sec are possible o Additional error beyond 1 C but within 5 C of last ACAL For ACBAND gt 2 MHz use 10 mV range temperature coefficient for all ranges Specifications apply from full scale to 5 of full scale DC lt 10 of AC sine wave input crest factor 1 4 and PRESET Within 24 hours and 1 C of last ACAL LO to Guard switch on Add 2 pp
28. OCCURS SAMPLE EVENT OCCURS TRIGGER ARM EVENT OCCURS START TAKE i READING ALL SPECIFIED ARMINGS DONE 34580PC F 4 2 Figure 17 Multiple trigger arming In the following program the NRDGS command selects 10 readings per trigger event The second parameter of the TARM command specifies 5 armings This program stores 5 groups of ten readings for a total of 50 readings 10 OPTION BASE COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 50 DIMENSION ARRAY FOR 50 READINGS 30 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 TARM HOLD HOLD TRIGGER ARM EVENT 50 OUTPUT 722 TRIG AUTO AUTO TRIGGER EVENT 60 OUTPUT 722 INBUF ON ENABLE INPUT BUFFER 70 OUTPUT 722 NRDGS 10 AUTO 10 READINGS TRIGGER AUTO SAMPLE EVENT 80 OUTPUT 722 TARM SGL 5 ARM TRIGGERING 5 TIMES 90 ENTER 722 Rdgs ENTER READINGS 100 PRINT Rdgs PRINT READINGS 110 END Making Synch rOnNOUS You can synchronize the multimeter to the controller by setting the trigger Readin gs arm trigger and or sample event to synchronous SYN The synchronous event occurs whenever the multimeter s output buffer is empty reading memory is off or empty and the controller requests data This means that measurements are made whenever the controller wants them This is a very important feature for remote operation especially when the multimeter is in the high speed mode In the high speed mode the synchron
29. PS 188 LFILTER prineri aai 190 161 51121 6 e re eer ere eerrae 190 UINE set sgsscicenteeiiteuniateesadensaneses 192 TO ca race tenetetntinaracaceonacctne 192 WATT S 193 MCOUNT ex faeces oasis 195 OEV ete eRe 196 DIO cee ieee oh cases tceencacs acne cuits cect 197 MFORMAT cep scsi ecesccontnscesoeasntiacectiranctteerne 198 IMT Ocopatccen seats artes 199 WISE ee reactance 202 NDI earan AE tone ERE 203 NPC eera ar Ea T TRN 204 NRDGS esnrisisisncsatscnciassaacsatidsvtaaetdelsinsienenauet 206 OCOMP aean caeceitureecetin eae 208 OFORMA Pianisi nee 209 OHM OHMF sonecie 213 OPT gorras aina eii a 213 PAUSE sisii 214 PER patie tanta eee nausea ein E 215 PRESET csspiiscacavtasisasvovkeaceinnepins ncticnsavteeenaet 216 PURGE hap aivsnsatauts eaten imne aa 218 QFORMAT caorainn aes 218 Rora 220 RANGE scsccseuit wens nann ON nE 220 RATIO viscitieeeicttenniavertstlevetn uataanteinteass 223 RES orenean REE EE 224 RESET ciancupnenninnaninanea 225 REV anena A E eins 227 RMA TH cissccessesccrresnnncteetaateieyessctedansavianssivennads 227 RMEM sassis ciisstcesteeniectaatvuveestecnesaiaessteaeedseiag es 228 ROS piierne a a 229 RSTATE nocino na E 230 SCAD crae E A E 231 SCRATCH scseasiiorvaahianentdanvectintcntieeeiiavenvents 231 SECURE cssssctssesattssensadsouscatsneseatesdeasesersasetivacs 231 SETAGY sieniin Ai E n aA NE 232 SLOPE bioanecioieieree io n 233 SMATH isasccspinaccu haan ethene tena oineakoumapaancavoise 234 SRO neirens inun
30. You can also specify resolution using the RES command Refer to the RES command in chapter 6 for examnples showing its usage 68 Chapter 3 Configuring for Measurements When to Specify Resolution For analog AC measurements if you default the _ resolution parameter the integration time will be that specified by the last NPLC command executed For sampled ACV or ACDCYV random sampling SETACV RNDM has a fixed resolution of 4 5 digits that cannot be changed For synchronous sampling SETACV SYNC a _resolution parameter of 0 001 7 5 digits 0 01 6 5 digits 0 1 5 5 digits and 1 4 5 digits For frequency and period measurements _ resolution specifies the gate time and the digits of resolution as shown in Table 19 For example the following program specifies frequency measurements from a voltage input using the 10V range The _resolution parameter in line 20 00001 specifies a gate time of second and 7 digits of resolution 10 OUTPUT 722 FSOURCE ACV 20 OUTPUT 722 FREQ 10 00001 30 END If you default the _resolution parameter for FREQ or PER measurements the multimeter sets resolution to 00001 which selects a gate time of 1 second and 7 digits of resolution Table 19 Frequency Period Gate Time and Resolution Y _resolution Selects Gate Digits of Parameter Time Resolution 00001 1s 7 0001 100ms 7 001 10ms 6 01 ims 5 1 100us 4 For analog ACV or ACDCV SE
31. a single occurrence of the SYN event satisfies all of the specified SYN event requirements This is shown in the second SYN Event example below e Query Command The NRDGS query command returns two responses separated by a comma The first response is the specified number of readings per trigger The second response is the present sample event Refer to Query Commands near the front of this chapter for more information Related Commands DELAY LEVEL RMEM SLOPE TARM TIMER TRIG SWEEP SYN Event In the following program line 70 requests data from the multimeter This satisfies the SYN event and initiates a reading The reading is then sent to the controller and printed The process repeats until the three readings have been taken and printed 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM A 3 DIMENSION ARRAY 30 OUTPUT 722 DCV 8 00125 DC VOLTAGE 10V RANGE 100pV RESOLUTION 40 OUTPUT 722 NRDGS 3 SYN 3 READINGS TRIGGER SYN SAMPLE EVENT 50 OUTPUT 722 TRIG AUTO AUTO TRIGGER MODE 60 ENTER 722 A ENTER READINGS 70 PRINT A PRINT READINGS 80 END In the following example SYN is specified for the trigger arm trigger and sample events Five readings per trigger are specified A single occurrence of the SYN event line 60 satisfies the trigger arm trigger and the first sample event and initiates the first reading Four more SYN events one for each reading are then required to init
32. an jesse FOR GUARDED MEASUREMENTS ONLY MOPE F 3 1 Figure 11 Voltage measurement connections DC Current The multimeter measures current by placing an internal shunt resistor across the input terminals measuring the voltage across the resistor and calculating the current current voltage resistance The multimeter s front and rear current inputs are protected by 1 A 250V fuses Figure 12 shows the front terminal connections for all types of current measurements The multimeter measures DC current on any of eight ranges Table 13 shows each DC current range and its full scale reading the full scale reading also shows the maximum number of digits for each range Table 13 also shows the maximum resolution and the shunt resistor used for each range Resolution is a function of the specified integration time refer to Setting the Integration Time later in the section for more information You specify DC current measurements using the DCI command For example to specify DC current measurements on the 10uA range send Chapter 3 Configuring for Measurements 55 OUTPUT 722 DCI 10 Table 13 DC Current Ranges p 6 DCI Range Full Scale Reading Maximum Resolution Shunt Resistor IOONnA 120 000nA 1pA 545 2kOQ 1pA 1 200000HA 1pA 45 2kQ 10yA 12 000000yA 1pA 5 2kQ 100UA 120 00000uA 10pA 7300 1mA 1 2000000mA IOOpA 100Q 10mA 12 000000mA 1nA 10Q 100mA 120 00000mA 10nA 10 1A 1 0500000A 100nA 0 19
33. cords 18 368 INDEX fuse installing the line 18 fuse replacing the line 21 line cycles specifying 59 line fuses 21 requirements line 17 switch 25 Power on self test 25 state 25 PRESET 216 PRESET FAST command 103 Presetting the multimeter 52 PURGE 218 Q QFORMAT 218 Queries standard 37 Query commands 37 153 standard 153 R R 220 Rack mount 20 Random ACDCV example fast 106 ACV example fast 106 sampling conversion 64 RANGE 220 Range specifying the 54 Ranging autoranging and manual 29 manual 30 RATIO 223 Ratio measurements 70 Read using implied 97 Reading error register 31 error registers 48 formats 92 GPIB address 42 memory using 94 numbers using 96 rate determining 109 rate increasing the 102 status register 77 Reading complete 112 Readings across the bus 98 configuring for fast 103 continuous 82 delayed 86 multiple 83 recalling 96 single 83 suspending 51 synchronous 84 timed 85 Recall 39 state key 33 Recalling readings 96 states 74 Reference frequency 58 Register reading the error 31 reading the status 77 Registers math 117 reading the error 48 REM annunciator 27 Remarks DCV 135 direct sampling 138 sub sampling 143 synchronous sampling 63 Remote command sending a 43 operating from 42 Repair service 22 Repairs warranty 22 Replacing current fuse 21 INDEX 369 line powe
34. however you may want to have more confidence that the multimeter is fully operational This is the job of the self test The self test performs a series of tests that check the multimeter s operability and accuracy Always disconnect any input signals before you run self test If you leave an input signal connected to the multimeter it cause a self test failure The self test takes over 50 seconds To run self test press Test Ee If the self test passed the display shows When self test passes you have a high confidence that the multimeter is operational and assuming proper calibration and autocalibration that measurements will be accurate If any of the tests failed the ERR annunciator illuminates and the display shows Reading the Error Register Note Note If the self test failed one or more error conditions have been detected Refer to the next section Reading the Error Register Whenever the display s ERR annunciator is illuminated one or more errors have been detected A record of hardware errors is stored in the auxiliary error register A record of programming and syntax errors is stored in the error register To read the error record s press Error The lowest numbered error and a description of the error is displayed For example a possible error message is Use the right arrow key to view the entire message When the error message has a 100 series numeric prefix e g 105
35. the integration time will be that specified by the last APER or NPLC command executed 1 You can also specify resolution using the RES command Refer to the RES command in Chapter 6 for examples showing its usage 60 Chapter 3 Configuring for Measurements When to Specify Resolution Autozero Note For DC or ohms measurements and analog AC measurements resolution is determined by the A D converter s integration time When you specify a resolution you are actually indirectly specifying an integration time Since the APER or NPLC command can also specify an integration time an interaction occurs when you specify resolution as follows e If you send the APER or NPLC command before specifying resolution the multimeter satisfies the command that specifies greater resolution more integration time e If you send the APER or NPLC command after specifying resolution the multimeter uses the integration time specified by the APER or NPLC command and any previously specified resolution is ignored For DC or ohms measurements you should specify resolution when the resolution provided by the NPLC or APER command is not sufficient For example in the following program line 10 specifies 1 PLC of integration time which provides 60dB of NMR and 7 digits ofresolution This produces an actual resolution of 1 uV on the 10V range For this application 100nV of resolution is required with a max _input of 10V The preceding equation produ
36. 0 40 OUTPUT 722 TIMER 2E 3 The time between readings measurement cycle to will correspond to the occur only 4 times yo TIMER setting 2E 3 or 2 ms 200 OUTPUT 722 TARM SLG 4 Four burst of measurements reducing the amount of j are allowed to begin when data necessary to the external triggers occur determine the ratio of the shaded areas in the input wave form INPUT WAVE FORM 100Hz damped sine wave f EN a dS c JUU TVU ee SYNC SIGNAL tor External Trigger TRIG EXT 20 ms MEASUREMENT BURSTS p by TRIG EXT and TIMEA NROGS 5 TIMER 2 ms Appendix E High Resolution Digitizing With the 3458A 353 354 TRIG is the next condition to be satisfied Only after both TARM and TRIG event conditions are satisfied can a burst measurement be made with NRDGS Refer to Figure 56 NRDGS of readings event lets you specify the number of readings to take the trigger condition for each reading and the number of readings saved in memory before or after the trigger event The SWEEP and SSRC commands are specifically designed to make the task of digitizing easier The SWEEP effective interval between readings number of readings command combines the NRDGS parameters with TIMER SSRC selects the synchronizing source for subsampling either external or level Both the SWEEP and SSRC commands are used for SSAC subsampled AC coupled and SSDC subsampled DC coupled and the NRDGS and TRIG are ignored
37. 10 100 1000 1000V xl Integration Time in Number Power Line Cycles 284 NPLC log scale Appendix A Specifications Additional error from Tcal or last ACAL 1 C Additional error from Tcal 5 C Specifications are for PRESET NPLC 100 For fixed range gt 4 min MATH NULL and Tcal 1 C Specifications for 90 day 1 year and 2 year are within 24 hours and 1 C of last ACAL Tcal 5 C MATH NULL and fixed range ppm of Reading specifications for High Stability Option 002 are in parentheses Without MATH NULL add 0 15 ppm of Range to 10 V 0 7 ppm of Range to 1 V and 7 ppm of Range to 0 1 V Without math null and for fixed range less than 4 minutes add 0 25 ppm of Range to 10 V 1 7 ppm of Range to 1 V and 17 ppm of Range to 0 1 V Add 2 ppm of reading additional error for Keysight factory traceability to US NIST Traceability error is the absolute error relative to National Standards associated with the source of last external calibration Add 12 ppm X Vin 1000 additional error for inputs gt 100 V Applies for 1 kQ unbalance in the LO lead and 0 1 of the line frequency currently set for LFREQ For line frequency 1 ACNMR is 40 dB for NPLC 1 or 55 dB for NPLC gt 100 For line frequency 5 ACNMR is 30 dB for NPLC 100 Reading Rate Auto Zero Off Selected Reading Rates 1 L 100 000 Readings
38. 121 INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS 125 SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED 150 FOR I 1 TO Num_readings 160 Rdgs I Int_rdgs I 165 FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE 170 R ABS Rdgs I 180 IF R gt 32767 THEN PRINT OVLD 190 Rdgs I Rdgs I S 200 Rdgs I OROUND Rdgs I 4 ASSIGN BUFFER I O PATH NAME TARM SYN TRIG AUTO DCV 10V 1 4us INTEGRATION TIME SINT OUTPUT FORMAT 130000 READINGS TRIGGER AUTO SAMPLE EVENT DEFAULT VALUE SYN EVENT TRANSFER READINGS INTO OFORMAT SINT NRDGS Num_readings ISCALE QUERY SCALE FACTOR FOR SINT FORMAT ENTER SCALE FACTOR CONVERT EACH INTEGER READING TO REAL USE ABSOLUTE VALUE TO CHECK FOR OVLD IF OVLD PRINT OVERLOAD MESSAGE MULTIPLY READING TIMES SCALE FACTOR ROUND TO 4 DIGITS Configuring the reading memory format MFORMAT command to match the output format QFORMAT command helps to ensure command to match the fastest transfer of readings from reading memory to the controller This is because no conversion is necessary when the readings are recalled from memory For high speed low resolution readings 3 5 or 4 5 digits made on a fixed range use the SINT format Because the SINT format uses only 2 bytes per reading multiple readings can be stored in memory and transferred across the bus faster using the SINT output format than an
39. 2 wire plus guard measurements C hang i ng the Therow ofkeys located directly under the display FUNCTION keys select the multimeter s standard measurement functions Table 7 shows the Measurement FUNCTION keys and the measurement function selected by each Function 28 Chapter 2 Getting Started Autorange and Manual Ranging Hold Note Table 7 Function Keys Key Description DCV DC voltage measurements cv x AC voltage measurements ORM 2 wire resistance measurements DCI DC current measurements ACI AC current measurements FREQ Frequency measurements ACOCV ACV AC DC voltage measurements OHMF OHM 4 wire resistance measurements ACDCI ACI AC DC current measurements PER ey FREQ Period measurements In addition to the functions selected by the FUNCTION keys the multimeter can perform direct sampled or sub sampled digitizing ratio measurements and AC or AC DC voltage measurements using the synchronous or random measurement methods These functions can be selected from the front panel by accessing the appropriate command s using the alphabetic menu keys these keys are discussed later in this section under Using the MENU Keys For more information on any measurement function or method refer to Chapter 1 In the power on state the multimeter automatically selects the appropriate measurement range This is called autorange In many cases you will probably want
40. 20 Num_readings 20 30 ALLOCATE REAL Rdgs 1 Num_readings 40 ASSIGN Dvm TO 722 readings to the computer using the DREAL format The ENTER statement is easier to use since no I O path is necessary but is much slower than the TRANSFER statement Also when using the ENTER statement you must use the FORMAT OFF command to instruct the controller to use its internal data structure instead of ASCII COMPUTER ARRAY NUMBERING STARTS AT NUMBER OF READINGS 20 CREATE ARRAY FOR READINGS ASSIGN MULTIMETER ADDRESS 50 OUTPUT Dvm PRESET NORM OFORMAT DREAL NPLC 10 NRDGS Num_readings 55 TRIG SYN DCV AUTORANGE 60 ASSIGN Dvm FORMAT OFF 70 FOR I 1 TO Num_readings 80 ENTER Dvm Rdgs I DREAL OUTPUT FORMAT 10 PLC 20 READINGS TRIG USE 8 BYTE WORD DATA STRUCTURE ENTER EACH READING 90 IF ABS Rdgs I 1 E 38 THEN IF OVERLOAD OCCURRED 1LOOPRINT OVERLOAD OCCURRED 110ELSE 120Rdgs I DROUND Rdgs 1 130PRINT Rdgs I 140END IF 150NEXT I 160END PRINT OVERLOAD MESSAGE IF NO OVERLOAD OCCURRED ROUND READINGS TO 8 DIGITS PRINT READINGS 8 Increasing the Reading Rate High Speed Mode This section discusses the multimeter s high speed mode and the factors that affect the reading rate It contains program examples that show how to increase the reading rate how to transfer readings at high speed directly to the controller how to perform high speed transfers from reading memory to the controlle
41. 3 Configuring for Measurements 53 OUTPUT 722 ARANGE ONCE Now when triggering begins the multimeter will select the correct range and then disable autorange Later if you need to enable autorange send OUTPUT 722 ARANGE ON Specifying the Range You specify a fixed range using the first parameter of one of the function commands ACV DCV OHM etc or the RANGE command This parameter is called max _inputsince you specify it as the input signal s maximum expected amplitude or the maximum resistance for resistance measurements The multimeter then chooses the correct range When specifying max input use the absolute value of the input signal no negative numbers For example to specify DC voltage with a maximum input of 2 5 volts send OUTPUT 722 DCV 2 5 In this case the multimeter selects the 10 VDC range To specify a different max_input e g 15V without changing the measurement function send OUTPUT 722 RANGE 15 In this case the multimeter selects the 100V range Note For frequency and period measurements the max _ input parameter specifies the maximum amplitude of the input signal It does not specify the frequency range Hz or the period range seconds You select the autorange mode by defaulting the max _input parameter or by specifying AUTO For example to select autorange using the DCV command send OUTPUT 722 DCV Refer to the FUNC or RANGE command in Chapter 6
42. 4 11 9 6 E eR ange 2 4 MHz 4 10 MHz 0 4 0 6 2 7 2 4 0 6 1 14 1 1 10mV 1V 0 02 0 08 1 2 08 0 5 10 V 1000 V 0 08 0 08 2 5 0 4 0 1 gt 5 0 32 0 022 Settling Characteristics For first reading or range change error using default delays add 0 01 of input step additional error The following data applies for DELAY 0 Function DC Component Settling Time ACV DC lt 10 o0ofAC 0 5 sec to 0 01 DC gt 10 of AC 0 9 sec to 0 01 ACDCV No instrument settling required 292 Appendix A Specifications Common Mode Rejection For 1 kQ imbalance in LO lead gt 90 dB DC to 60 Hz Maximum Input Rated Input Non Destructive HI to LO 1000 Vpk 1200 V pk LO to Guard 200Vpk 350 V pk Guard to Earth 500Vpk 1000 V pk Volt Hz Product 1x 108 5 AC Current AC Current ACI and ACDCI Functions Maximum Shunt Burden Temperature Coefficient 1 Range Full Scale Resolution Resistance Voltage of Reading of Range C 100 pA 120 0000 100 pA 7300 0 1 V 0 002 0 1mA 1 200000 lI nA 100 Q 0 1 V 0 002 0 10 mA 12 00000 10 nA 10 Q 0 1 V 0 002 0 100 mA 120 0000 100 nA 1Q 0 25 V 0 002 0 1A 1 050000 l pA 0 10 lt 15V 0 002 0 AC Accuracy 2 24 Hour to 2 Year Reading Range 10 Hz to 20 Hzto 45Hzto 100Hzto 5kHzto 20kHzto 50kHzto Range 20 Hz 45 Hz 100 Hz 5 kHz 20 kHz 50 kHz 100 kHz 100 uA 0 4 0 03 0 15 0 03 0 06 0 03 0 06 0 03 1mA 100mA_ 0 4 0 02 0 15 0 02 0 06 0 02 0 03 0 02 0 06 0 0
43. 50 000 Samples sec Sample Timebase Test Input 2 x full scale pk pk Result Accuracy 0 01 DFT harmonics 20 kHz lt 90 dB Jitter lt 100 ps rms DFT harmonics 1 005 MHz lt 60 dB External Trigger DFT spurious 20 kHz lt 90 dB ane lt 15 nss Differential non linearity 20 kHz lt 0 005 of Range litter a5 hale Signal to Noise Ratio 20 kHz gt 66 dB i 296 Appendix A Specifications Level Trigger Latency lt 700 ns Jitter lt 100 ps for 1 MHz full scale input Maximum DC voltage limited to 400 V DC in DSAC or SSAC functions 1 C and within 24 hours of last ACAL ACV Limited to 1 x108 V Hz product Effective sample rate is determined by the smallest time increment used during synchronous sub sampling of the repetitive input signal which is 10 ns lt 25 ns variability between multiple 3458As 8 System Specifications Function Range Measurement The time required to program via GPIB a new measurement configuration trigger a reading and return the result to a controller with the following instrument setup PRESET FAST DELAY 0 AZERO ON OFORMAT SINT INBUF ON NPLC 0 TO FROM Configuration Description GPIB Rate Subprogram Rate DCV lt 10 V to DCV lt 10 V 180 sec 340 sec any DCV OHMS to any DCV OHMS 85 sec 110 sec any DCV OHMS to any DCV OHMS with DEFEATON 150 sec 270 sec TO or FROM any DCI 70 sec 90 sec TO or FROM any ACV or ACI 75 sec 90 sec Selected Operating Rates 2 Cond
44. 6 DELAY 1 NRDGS 2 TRIG SGL This is the same program as the Subprogram Program but the display is turned off The test execution time is cut in half Azero Off Subprogram Azero test execution time 510 s program memory download time 280 s reading transfer time 180 s This is the same program as the Subprogram Display but Auto Zero is turned off There is no real advantage in test of this type because the reading speed is so fast that there really isn t much difference between leaving auto Zero on or off In some cases it may be faster when changing function or integration time to leave Auto Zero On Defeat On Subprogram Defeat test execution time 470 s program memory download time 280 s reading transfer time 180 s 2690 SUB Defeat REAL Dnld_time Exe time Tns_ time 2700 DIM A 37 2710 Dnid_time TIMEDATE 2720 OUTPUT 722 PRESET DISP OFF TESTING MFORMAT SREAL DEFEAT ON 2730 OUTPUT 722 SUB 1 MEM FIFO OHM 1E4 NPLC 0 DELAY 0 NRDGS 15 TRIG SGL 2740 OUTPUT 722 0HM 1E5 NRDGS 8 TRIG SGL This is the same program as the Subprogram Display but the DEFEAT function is turned on In this mode of operation some of the overload detection and protection circuitry is defeated If a voltage of greater than 300 V is detected the defeat feature is turned off and the event is noted in the 3458A s memory This feature allows faster function and range changes but should not be as a matter of practice abused Appen
45. 6 GPIB chip failure 128 7 UART failure 256 8 Timer failure 512 9 Internal overload 1024 10 ROM checksum failure low order byte 2048 11 ROM checksum failure high order byte 4096 12 Nonvolatile RAM failure 8192 13 Option RAM failure 16384 14 Cal RAM write or protection failure The auxiliary error register indicates hardware related errors If one or more bits are set the multimeter needs calibration or repair The AUXERR command returns a 0 if no error bits are set e Ifany bit in the auxiliary error register is set the multimeter sets bit 0 hardware error in the error register Reading the auxiliary error register does not clear bit 0 in the error register You must read the error register ERR command to clear it Bits in the auxiliary error register cannot be masked to prevent them from setting bit 0 in the error register e Related Commands EMASK ERR ERRSTR TEST 10 OUTPUT 722 AUXERR READS THE AUXILIARY ERROR REGISTER 20 ENTER 722 A ENTERS WEIGHTED SUM INTO VARIABLE A 30 PRINT A PRINTS THE WEIGHTED SUM 40 END As an example assume the AUXERR command returns the weighted sum 3072 This means that the errors with weighted values of 1024 ROM checksum low order byte and 2048 ROM checksum high order byte have occurred Autozero Enables or disables the autozero function The autozero function applies only to DC voltage DC current and resistance measurements AZERO control 162 Cha
46. 722 SUBEND 90 100 OUTPUT 722 CALL DMM CONE 110 END Any variables whether simple or array can be used in numeric calculations Several math functions are available in the 3458A command set to allow you to manipulate data The 3458A s math functions are described in more detail later in this supplement The OUTPUT command returns the value of a specified variable An example is included below to illustrate the use of the OUTPUT command 10 DIM AS 50 Dimension controller variable 20 OUTPUT 722 LET VAL COS 5235 Compute value 30 OUTPUT 722 OUTPUT VAL 40 ENTER 722 AS 50 PRINT AS 60 END Read result into variable Enter result Print result You can allocate memory space in the 3458A for one dimensional arrays For real arrays use either the DIM name size or REAL name size commands to define the array For integer arrays use the INTEGER name size command All arrays have a lower bound of zero option base 0 Arrays do not have a default size For example to create a 10 element array specify a size of 9 as shown below OUTPUT 722 DIM TESTER 9 Array names are subject to the same rules as numeric variable names To specify a particular array element you must specify the subscript enclosed in parentheses The range of subscripts is an integer from 0 through 999 but Chapter 7 BASIC Language for the 3458A the maximum array size is determined by available 3458A memory approximately 10 kbytes if no s
47. 722 ACV 10 UTPUT 722 SETACV SYNC UTPUT 722 SSRC EXT NTER 722 A RINT A ND TARM AUTO TRIG SYN NRDGS 1 AUTO AC VOLTAGE 10V RANGE SYNCHRONOUS METHOD EXTERNAL SYNC SOURCE EVENT TRIGGER READING TRIG SYN ENTER READING PRINT READING Chapter 6 Command Reference 243 SSTATE SSTATE Syntax Remarks Store State Stores the multimeter s present state and assigns it a name States are recalled using the RSTATE command SSTATE name name State name A state name may contain up to 10 characters The name can be alpha alphanumeric or an integer in the range of 0 to 127 When using an alphanumeric name the first character must be alpha Alpha or alphanumeric state names must not be the same as multimeter commands or parameters or the name of a stored subprogram The characters _ and can also be used in an alpha or alphanumeric name When using an integer state name 0 127 the multimeter assigns the prefix STATE to the integer when the state is stored This differentiates an integer state name from an integer subprogram name For example a state stored with the name 8 will be recorded as STATES The state can be recalled later using either the name 8 or STATES State 0 is reserved for the multimeter s power down state see first Remark below Power on name none Default name none parameter required Whenever the multimeter s power is removed the present state is stored in state 0 After a powe
48. A 40 END Autocalibration The multimeter has four autocalibration autocal routines DCV AC OHMS and ALL These routines improve short term accuracy for many or all measurement functions but are not substitutes for periodic external calibration of the multimeter The measurement functions affected by each 48 Chapter 3 Configuring for Measurements Note Running Autocal When to Use Autocal routine are e The DCV routine enhances all measurement functions This routine takes about 1 minute to perform The AC routine performs specific enhancements for AC or AC DC voltage all measurement methods AC or AC DC current direct or sub sampled digitizing AC or DC coupled frequency and period measurements The AC routine takes about 1 minute to perform The OHMS routine performs specific enhancements for 2 or 4 wire ohms DC current and AC current measurements The OHMS routine takes about 10 minutes to perform The ALL routine enhances all measurement functions by performing all of the above routines The ALL routine takes about 11 minutes to perform You should not cycle power or reset the multimeter while an autocal routine is being performed If you do the multimeter generates the ACAL REQUIRED error since many or all of its autocal constants have been erased You must then perform the ALL routine to eliminate the error Since the DCV routine applies to all measurement functions you shoul
49. After editing the string press the Enter key to execute the string The previous string is still assigned to the user defined key An edited string cannot be re assigned to a user defined key If you want to change a key definition you must repeat the above steps Figure 9 shows the keyboard over lay that fits over the USER keys You can write on this overlay with a pencil to identify the command s assigned to each user defined key eI as OUL 34580PC F 2 4 Figure 9 Keyboard overlay Keysight part number 03458 84303 The overlay is held in place by two tabs that secure it to the collar around numeric key 5 To install the overlay insert the overlay s left tab into the left side of the collar Bend the overlay as shown in Figure 10 and press the right tab into the collar Chapter 2 Getting Started 41 Figure 10 Installing the keyboard overlay Operating from Remote Input Output Statements Reading the GPIB Address 42 Chapter 2 Getting Started This section shows you the fundamentals of operating the multimeter from remote This includes reading and changing the GPIB address sending a command to the multimeter and retrieving data from the multimeter The statements used to operate the multimeter from remote depend on the computer and its language In particular you need to know the statements the computer uses to input and output information For example the input statements for the Hewlett Packard Series 2
50. Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches Introduction ssai EaR 311 Tools REQUITER isirrcisseiisiiciiicaiireiei as 311 Procedure ees cccscke ccnddesecettiaoaittalesteteledantedeneacs EiS 311 Covers Removal Procedure c ccccceeeeees 312 Guard Pushrod Removal Procedure 314 Front Rear Pushrod Removal Procedure 314 Switch Cap Installation Procedure 4 316 Covers Installation Procedure c c cece 318 Appendix D Optimizing Throughout and Reading Rate Introducing the 3458A oo ceecccesceeeeeeeeeeeeeeeeeees 321 Application Oriented Command Language 321 Intrinsically Slow Measurements 0 321 Maximizing the Testing Speed ceseeeeeeeee 322 Program Memory ceeceseeseesteceteeeneeeeeeeees 322 State SOT se asserens r nania A a 322 Reading Analysis cccccsessesscestecsteeseesseeeees 322 Task Grouping and Sequence 322 System Uptime senrsieinsrsniioiiimiriiisiie 323 PULPOSE lt ccssaccessceeiavanaceasnsevannereedde niea 323 Topics Covered in the Product Note include 323 DC Volts DC Current and Resistance 323 Optimizing Through the DCV Path 324 DC Current reconocen en ane 326 RESIStANCE seenilsesei inisenisi disband a 326 Optimizing Through the Track and Hold Path Direct Sampling and Subsampling 328 AC Volts and AC Current osese 328 Analog AGV wii
51. CREATE ARRAY FOR SAMPLES ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS ASSIGN Int_samp TO BUFFER Int_samp ASSIGN BUFFER I O PATH NAME OUTPUT Dvm PRESET FAST LEVEL SLOPE SSRC LEVEL SSDC 10 FAST OPERATION TARM SYN LEVEL SYNC SOURCE OV POSITIVE SLOPE DEFAULT VALUES SUB SAMPLING SINT OUTPUT FORMAT 10V RANGE OUTPUT Dvm SWEEP Eff int Num_samples 2us EFFECTIVE INTERVAL 1000 SAMPLES TRANSFER Dvm TO Int_samp WAIT SYN EVENT TRANSFER READINGS INTO INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR SINT FORMAT ENTER Dvm S ENTER SCALE FACTOR OUTPUT Dvm SSPARM QUERY SUB SAMPLING PARAMETERS ENTER Dvm N1 N2 N3 ENTER SUB SAMPLING PARAMETERS FOR I 1 TO Num_samples Samp I Int_samp I CONVERT EACH INTEGER READING TO REAL FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE R ABS Samp I USE ABSOLUTE VALUE TO CHECK FOR OVLD IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE Samp I Samp I S MULTIPLY READING TIMES SCALE FACTOR Chapter 6 Command Reference 239 SSPARM 220 Samp I DROUND Samp I 4 ROUND TO 4 DIGITS 230 NEXT I 230 Las sar gee a E SORT SAMPUBRO SsSSStSSSsssSsSSeaneae esses 240 Inc N1 N2 TOTAL NUMBER OF BURSTS 250 K 1 260 FOR I 1 TO N1 270 L I 280 FOR J 1 TO N3 290 Wave_form L Samp K 300 K K 1
52. DCV command and using the RES command both set the 3458A to DCV the 100 V range the integration period to 8 us and set the resolution to 001 of 20 V The reading rate can be doubled simply by turning the auto zero operation off Auto zero on AZERO ON is the default condition of the 3458A In this condition to eliminate any thermally generated offset voltage on the input of the 3458A internally the input is shorted and a measurement is made to establish the offset voltage The measured DC offset is subtracted from the actual input voltage and presented to the output as the final answer Hence there are really two measurement cycles normally involved in one measurement This procedure ensures the specified accuracy of the 3458A but it can produce measurements only half as fast as just measuring the input voltage In a thermally stable environment very little reduction in accuracy over a short period of time 10 minutes or so results from disabling this function Hence beyond reducing the integration period AZERO OFF is the most significant command you may use to increase reading rate The same general discussion for measuring DCV applies to current With the exception that the current input is a separate terminal the command DCI is used the same way that DCV is used The current measurement path is selected with a series armature relay instead of the faster reed relays of DC volts and Ohms hence switching between current and other funct
53. DIMA 100 B 100 C 100 D 100 E 100 F 100 G 100 H 100 I 100 Set_up 100 40 INTEGER I M 50 REAL Readings 37 BUFFER 60 ASSIGN Dmm TO 722 70 ASSIGN Buf_1 TO BUFFER Commands 80 ASSIGN Buf_2 TO BUFFER Readings 90 CLEAR 722 00 OUTPUT Dmm RESET 110 Set_up PRESET MFORMAT SREAL DEFEAT ON APER 100E 6 DISP OFF TESTING 20 BS SUB Try MEM FIFO DELAY O 0OHM 1E4 NRDGS 15 TRIG SGL 30 CS 0HM 1E5 NRDGS 8 TRIG SGL 40 DS DELAY 1 OHMF 1E3 NRDGS 2 TRIG SGL 50 ES DELAY 1 ACBAND 50 ACV 250 NRDGS 1 TRIG SGL 60 FS DELAY 01 ACBAND 25000 ACV 10 TRIG SGL 70 GS DELAY 0 DCV 10 NRDGS 6 TRIG SGL 80 H DELAY 01 ACBAND 5000 ACV 10 NRDGS 1 TRIG SGL 90 IS DELAY 0 DCV 10 NRDGS 3 TRIG SGL SUBEND 200 Command B amp C amp D amp ES amp FS amp G amp HS amp 1 210 Dnload Transfer commands to dmm 220 Dnid_time TIMEDATE 230 OUTPUT Dmm Set_up 240 TRANSFER Buf_ 1 TO Dmm 250 Dnld_time TIMEDATE Dnld_ time 260 Execute Dmm Execution time 270 Exe time TIMEDATE 280 OUTPUT Dmm CALL Try 290 Exe time TIMEDATE Exe time 300 Read Transfer the readings to the Computer 310 Tns_time TIMEDATE 320 TRANSFER Dmm TO Buf 2 330 Tns_time TIMEDATE Tns_ time 340 PRINT DOWN LOAD TIME Dnld_time Appendix D Optimizing Throughout and Reading Rate 350 360 370 380 10 20 30 40 50 60 70 80 90 00 10 20 30 40 50 60 70 80 90 200 210 220 230 240 250 2
54. EN 45014 Manufacturer s Name Agilent Technologies Incorporated Manufacturer s Address 815 14 ST S W Loveland CO 80537 USA Declares that the product Product Name Multimeter Model Number 3458A Product Options This declaration covers all options of the above product s Conforms with the following European Directives The product herewith complies with the requirements of the Low Voltage Directive 73 23 EEC and the EMC Directive 89 336 EEC including 93 68 EEC and carries the CE Marking accordingly Conforms with the following product standards EMC Standard Limit IEC 61326 1 1997 A1 1998 EN 61326 1 1997 A1 1998 IEC 61000 4 2 1995 A1 1998 EN 61000 4 2 1995 ee IEC 61000 4 3 1995 EN 61000 4 3 1995 3 Vim 60 1000 MHz IEC 61000 4 5 1995 EN 61000 4 8 1996 0 5 KV lierine 1 KV ine ground IEC 61000 4 11 1994 EN 61000 4 11 1994 eee ee Interrupt gt 95 5000ms Canada ICES 001 1998 Australia New Zealand AS NZS 2064 1 The product was tested in a typical configuration with Agilent Technologies test systems Safety IEC 61010 1 1990 A1 1992 A2 1995 EN 61010 1 1993 A2 1995 Canada CSA C22 2 No 1010 1 1992 UL 3111 1 1994 8 March 2001 Date Ray Corson Product Regulation Program Manager For further information please contact your local Agilent Technologies sales office agent or distributor Authorized EU representative Agilent Technologies Deutschland GmbH Herrenberger Stra e 130 D 7
55. Errors associated with digitizing can be grouped by their amplitude error and time error contributions to the total error in the measurement For dynamic signals time errors result in amplitude error Fortunately most time dependent measurements are differential and any absolute timing errors are calibrated out of the measurement A close look at the block diagram of the 3458A reveals the sources of error in the measurement summarized in Figure 60 Broadly speaking errors that creep into digitizing measurements are evident in both the amplitude and time axes For amplitude the errors are 1 Quantization error 2 Missing code 3 Non linearity 4 Noise 5 Bandwidth 6 Amplitude accuracy On the time axes the error factors are 1 Timebase reference jitter 2 Trigger uncertainty 3 Trigger accuracy 358 Appendix E High Resolution Digitizing With the 3458A Amplitude Errors 4 Trigger latency 5 Aperture width 6 Aperture jitter F igure 60 These aio Roti eye o Switching Noise digitizing error sources Amplifier Noise should be considered in any measurement ADC TRACK AND HOLD Quantization Error Aperture Jitter Non Linearity Broadband Noise Amplitude Accuracy Aperture Width OUTPUT TRIGGER Timing Jitter Timing Accuracy Trigger Uncertainty The input signal conditioning section of the 3458A has switches relays attenuators and amplifiers associated with conditioning and
56. FACTOR 210 Samp I DROUND Samp 1 8 ROUND CONVERTED READING 220 PRINT Samp I PRINT READINGS 230 NEXT 240 END Error Mask Enables certain error condition s to set the error bit bit 5 in the status register EMASK value You enable an error condition by specifying its decimal weight as the value parameter To enable more than one error condition specify the sum of the 174 Chapter 6 Command Reference Remarks Examples EMASK weights The error conditions and their weights are Weighted Bit Value Number Error Conditions 1 0 Hardware error see AUXERR for more information 2 1 Calibration error 4 2 Trigger too fast error 8 3 Syntax error 16 4 Command not allowed from remote ADDRESS command 32 5 Undefined parameter received 64 6 Parameter out of range 128 7 Memory Error 256 8 Destructive overload detected 512 9 Out of calibration 1024 10 Calibration required 2048 11 Settings conflict memory improperly configured for sub sampling 4096 12 Math error divide by 0 integer overflow etc 8192 13 Subprogram error calling a deleted sub CONT with no PAUSE SUBEND or PAUSE only allowed in sub SCRATCH DELSUB CONT not allowed in sub 16384 14 System error Power on value 32767 all enabled Default value 32767 all enabled e When an error occurs it sets the corresponding bit in the error register regardless of whether or not it has been enabled by the EMASK command Disabli
57. FSOURCE source The source parameter choices are Numeric source Query Parameter Equiv Description measurement capabilities ACV 2 AC voltage FREQ 1Hz 10MHz PER 100ns 1s ACDCV 3 AC DC voltage FREQ 1Hz 10MHz PER 100ns Is ACI 7 AC current FREQ 1Hz 100kHz PER 10us 1s ACDCI 8 AC DC current FREQ 1Hz 100kHz PER 10us 1s Power on source ACV Default source ACV Query Command The FSOURCE query command returns the present frequency source Refer to Query Commands near the front of this chapter for more information e Related Commands FREQ FUNC PER 10 OUTPUT 722 FSOURCE ACDCI SELECTS ACDCI AS THE INPUT SOURCE 20 OUTPUT 722 FREQ l Ol SELECTS FREQUENCY 100mA RANGE 1ms 25 GATE TIME 4 DIGITS OF RESOLUTION 30 END 182 Chapter 6 Command Reference FUNC Syntax function max _input FUNC Function Selects the type of measurement AC voltage DC current etc It also allows you to specify the measurement range and resolution The FUNC header is optional and may be omitted FUNC function max _input _resolution or FUNC function max _input _resolution The function parameter designates the type of measurement The parameter choices are Numeric function Query Parameter Equiv Description DCV 1 Selects DC voltage measurements ACV 2 Selects AC voltage measurements the mode is set by the SETACV command ACDCV 3 Selects AC DC voltage measurements t
58. NPLC is rounded up to the next integer If NPLC gt 10 then the actual value of NPLC is rounded up to the next integer multiple of 10 For values of NPLC lt 1 the value selected is used much the same as aperture except that the integration period is scaled in terms of the line frequency For example if the value selected for NPLC is 1 PLC the 3458A actually sets the integration period to 1X line period to the nearest 100 ns gt or 0016666s 60 Hz operation The query NPLC returns 99 9958E 3 PLC Ifthe value of 2 5 is selected for NPLC then the 3458A sets the integration period to 3 PLC If the value of 21 is selected for NPLC then the integration period is set to 30 PLC NPLC 0 always selects the shortest integration period possible 500 ns or 29 99994E 6 PLC 60 HZ operation Another command that affects the integration period is the resolution command RES which selects the number of digits of the reading displayed as a function of a percentage of the maximum input parameter The resolution of the measurement is selected as a part of the function command or as the RES command It sets the integration period to a value that will allow the ADC to convert the measurement to the resolution requested For example DCV 20 001 using the resolution parameter of this command Appendix D Optimizing Throughout and Reading Rate 325 326 DC Current Resistance and DCV 20 RES 001 omitting the resolution parameter of the
59. NRDGS 256 TIMER TIMER 20E 6 APER 3E 6 MFORMAT SINT Chapter 6 Command Reference PURGE QFORMAT Remarks Examples Syntax Remarks Example Syntax PURGE OFORMAT SINT Related Commands RESET OUTPUT 722 PRESET NORM CONFIGURES FOR REMOTE OPERATION OUTPUT 722 PRESET FAST CONFIGURES FOR FAST READINGS TRANSFER OUTPUT 722 PRESET DIG CONFIGURES FOR FAST DCV DIGITIZING Purge State Removes a single stored state from memory PURGE name name State name A state name may contain up to 10 characters The name can be alpha alphanumeric or an integer in the range of 0 to 127 Refer to the SSTATE command for details Power on name none Default name none parameter required To delete all stored states use the SCRATCH command e Related Commands DELSUB SCRATCH OUTPUT 722 PURGE A2 PURGES STORED STATE A2 Query Format Designates whether query responses contain numeric or alpha characters whenever possible and whether command headers are returned QFORMAT pe format The type parameter choices are Numeric type Query Parameter Equiv Description NUM 0 Query responses sent to either GPIB or the display are numeric only whenever possible with no headers Chapter 6 Command Reference 219 QFORMAT 220 Examples Numeric type Query Parameter Equiv Description NORM 1 Query responses sent to the GPIB are numeric only whenever possible with no headers que
60. OHMS MEASUREMENTS 30 OUTPUT 722 MEM FIFO ENABLES READING MEMORY FIFO MODE 40 OUTPUT 722 NRDGS 5 5 READINGS PER SAMPLE EVENT AUTO 50 OUTPUT 722 TARM SGL ENABLES ONE SERIES OF MEASUREMENTS 60 END 10 OUTPUT 722 DCV SELECTS DC VOLTAGE MEASUREMENTS 20 OUTPUT 722 TARM HOLD SUSPENDS MEASUREMENTS 30 OUTPUT 722 TRIG AUTO SELECTS AUTO AS THE TRIGGER EVENT 40 OUTPUT 722 MEM FIFO ENABLES READING MEMORY FIFO MODE 50 OUTPUT 722 NRDGS 3 AUTO 3 READINGS PER SAMPLE EVENT AUTO 60 OUTPUT 722 TARM SGL 5 SELECTS MULTIPLE ARMING FOR 5 CYCLES 70 END In this program line 60 arms the trigger once for each measurement cycle This occurs five times After the fifth cycle trigger arming reverts to HOLD This program places 15 readings 3 readings per trigger event 5 times into reading memory Unless the input buffer is enabled line 60 causes the GPIB bus to be held until Chapter 6 Command Reference TBUFF Syntax Remarks Example TBUFF all measurement cycles are complete If you want to regain control of the bus immediately suppress the cr If by replacing line 60 with 60 OUTPUT 722 USING K TARM SGL 5 In the above line the image specifier suppresses the cr If The K image specifier suppresses trailing or leading spaces and outputs the command in free field format Notice the semicolon following the TARM SGL 5S This indicates the end of the command to the multimeter and must be present wh
61. SGL command followed by the LINE LEVEL controller requesting data one reading is taken per sample event until the specified number of readings are completed The trigger arm event then becomes HOLD SYN AUTO SYN After the controller requests data 2 which satisfies both SYN events the first reading is taken One reading is then taken per SYN event until the specified number of readings are completed SYN AUTO AUTO EXT TIMER After the controller requests data one reading is taken per LINE LEVEL sample event until the specified number of readings are completed SYN EXT AUTO EXT TIMER After the controller requests data followed by a negative LINE LEVEL edge transition on the Ext Trig input one reading is taken per sample event until the specified number of readings are completed SYN EXT SYN Illegal SYN LEVEL AUTO EXT TIMER After the controller requests data followed by the LEVEL occurrence of the LEVEL event one reading is taken per sample event until the specified number of readings are completed SYN LEVEL SYN LINE Illegal SYN LINE AUTO EXT TIMER After the controller requests data followed by the power line LINE voltage crossing zero volts one reading is taken per sample event until the specified number of readings are completed SYN LINE SYN LEVEL Illegal SYN SGL Any Illegal SYN SYN SYN After the controller requests data all three events are satisfied and the first reading is tak
62. Single Real SREAL or Double Real DREAL Unlike the SINT and DINT formats readings stored in SREAL or DREAL format are not scaled and can be used with any measurement function multimeter configuration Since there is no scale factor the SREAL and DREAL formats are ideal when auto ranging and or a math function is enabled Use the SREAL format for measurements with lt 6 5 digits of resolution Use the DREAL format for measurements with gt 6 5 digits of resolution 1 The ASCII format is actually 15 bytes for the reading plus 1 byte per reading for a null character which is used to separate stored ASCII readings only Chapter 4 Making Measurements 95 ASCII This memory format can be used for any measurement function multimeter configuration Since ASCII has the greatest number of bytes per reading you should use it only when the output format is ASCII measurement speed is not critical and the number of readings to be stored is not great The MFORMAT command specifies the reading memory format the power on and default format is SREAL For example to select the single integer format send OUTPUT 722 MFORMAT SINT Overload Indication The multimeter indicates an overload condition input greater than the present range can measure by storing the value 1E 38 in reading memory instead of a reading When overload values are recalled to the display the value 1E 38 is displayed When overload values are transferred from rea
63. TEST command indicates the end of the command to the multimeter and must be present when you suppress cr If Multiple commands separated by semicolons may be sent in one command string For example the following command string contains 3 multimeter commands OUTPUT 722 TRIG HOLD DCV 3 NPLC 10 Numbers specified as command parameters can be either integer floating point or exponential in format Parameters in floating point format are rounded to the nearest integer if the command requires an integer For example SUB 2 49 is rounded down to SUB 2 and SUB 2 5 is rounded up to SUB 3 You can default a parameter by omitting it or replacing it with 1 minus 1 For example to specify 10 for the first parameter and default the second parameter send OUTPUT 722 ACV 10 152 1 GPIB General Purpose Interface Bus is Keysight Technology s implementation of IEEE Standard 488 1978 and ANSI MC1 1 Chapter 6 Command Reference Query Commands Standard Query Commands Additional Query Commands Introduction or OUTPUT 722s ACV L0 L From remote only you can use two commas to indicate a default value For example to specify 10 for the first parameter and default the second parameter send OUTPUT 722 ACV 10 To default the first parameter which selects autorange in this example and specify 01 for the second parameter send OUTPUT 722 ACV 01 A query command ends with a question
64. TRANSFER Dvm TO Int_samp WAIT SYN EVENT TRANSFER READINGS INTO 21 INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS 25 SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED 30 OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR SINT FORMAT 40 ENTER Dvm S ENTER SCALE FACTOR 50 OUTPUT Dvm SSPARM QUERY SUB SAMPLING PARAMETERS 60 ENTER Dvm N1 N2 N3 ENTER SUB SAMPLING PARAMETERS 70 FOR I 1 TO Num_samples 80 Samp I lnt_samp I CONVERT EACH INTEGER READING TO REAL 90 FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE 90 R ABS Samp I USE ABSOLUTE VALUE TO CHECK FOR OVLD 200 IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE 210 Samp I Samp I S MULTIPLY READING TIMES SCALE FACTOR 220 Samp I DROUND Samp I 4 ROUND TO 4 DIGITS 230 NEXT I 2300 Sere SSeS Seas DOR SAMBURS S355 S558 SSS S SSeS SSeS Sse SSeS 240 Inc N1 N2 TOTAL NUMBER OF BURSTS 250 K 1 260 FOR I 1 TO N1 270 L 1 280 FOR J 1 TO N3 290 Wave _form L Samp K 300 K K 1 310 L L Inc 320 NEXT J 330 NEXT I 340 FOR I N1 1 TO N1 N2 350 L I 360 FOR J 1 TO N3 1 370 Wave_form L Samp K 380 K K 1 390 L Lt Inc 400 NEXT J 410 NEXT I 420 END Chapter 6 Command Reference TARM Syntax Syntax i T is an abbreviation for the TRIG command T event Refer to the TRIG command for more information Trigger arm Defines the event that enabl
65. TRIGGER AUTO SAMPLE EVENT 100 OUTPUT 722 TARM EXT EXTERNAL TRIGGER ARM EVENT 110 OUTPUT 7223 TRIG SGL SINGLE TRIGGER EVENT 120 OUTPUT 722 DISP MSG TEST FINISHED INDICATE SUBPROGRAM IS DONE 130 OUTPUT 722 SUBEND 140 END Subprogram End Signals the end of a subprogram SUBEND e When storing a subprogram SUBEND signals the end of the subprogram When a subprogram has been executed SUBEND sets bit 1 if enabled in the status register which signals the subprogram s completion e Related Commands CALL COMPRESS CONT DELSUB PAUSE SCRATCH SUB See the SUB example on the preceding page The SWEEP command specifies the effective_interval between samples readings and the total number of samples taken per trigger event most measurement functions or per trigger arm event sub sampling only SWEEP effective_interval _samples effective_interval For sub sampling SSAC or SSDC this parameter specifies the spacing of samples in the reconstructed waveform see Chapter 5 for details For all other measurement functions this parameter specifies the actual time interval from one 248 Chapter 6 Command Reference Remarks Example SWEEP sample to the next For sub sampling the valid range of this parameter is 10E 9 to 6000 seconds with 10ns increments for all other measurement functions the range is 1 maximum reading rate to 6000 seconds in 100ns increments Power on effective_interval 100E 9 Defa
66. The ERRSTR command returns two responses separated by a comma The first response is an error number 100 series error register 200 series auxiliary error register and the second response is a message string explaining the error ERRSTR The maximum string length returned by ERRSTR is 255 characters The ERRSTR command reads and clears only the least significant set bit in a register If more than one bit is set in a register you must execute ERRSTR repetitively to read and clear each set bit After all set bits have been read and cleared or if there were no set bits in either register the ERRSTR command returns 0 NO ERROR When the auxiliary and error registers are cleared the error bit in the status register bit 5 will also be cleared When bit 0 in the error register is set it means that one or more bits in the auxiliary error register are set In this case the ERRSTR command reads and clears each set bit in the auxiliary error register first When all auxiliary errors have been read bit 0 in the error register is cleared and the ERRSTR command can then be used to read any remaining errors in the error register e Related Commands AUXERR EMASK ERR QFORMAT 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM A 200 DIMENSION STRING VARIABLE 30 OUTPUT 722 ERRSTR READS ERROR MESSAGE 40 ENTER 722 A A ENTERS NUMERIC INTO A STRING INTO A 50 PRINT A AS PRINTS RESPONSES 60 IF A gt 0 T
67. This path uses a 16 bit track and hold circuit between the input and the A to D to take a snapshot of the input DCV may be measured up to a maximum reading rate of 50 000 readings per second through this path The commands for this choice of path are DSAC direct sample AC coupled DSDC direct sample DC coupled SSAC subsampled AC coupled SSDC subsampled DC coupled The Product Note 3458A 2 High Resolution Digitizing with the 3458A System Multimeter covers the use of these commands in detail along with their associated trigger commands and constraints In general the aspects of these commands that most influence throughput are those associated with ACV where the 3458A handles the task of measuring the rms value of either repetitive wave forms with the synchronous ACV or noise measurements with random ACV A detailed look at the techniques and the trade offs of the three methods of rms ACV measurement is in the next section AC Volts and AC Current Analog ACV Synchronous ACV Random ACV The 3458A Multimeter has the unique capability of offering the user three different ways of measuring equivalent DCV heating value of an input wave form true root mean square value analog ACV synchronous ACV and random ACV The input signal follows the track and hold path see Figure 47 where it may be routed into the analog AC to DC converter or the track and hold circuit The analog ACV offers broadband 10Hz to 2 MHz rms capabilit
68. USING IMPLIED READ 105 PERFORM NULL OPERATION ON EACH 110 PRINT Rdgs PRINT NULL MODIFIED READINGS 120 END SCALE The SCALE operation modifies each reading by subtracting an offset and dividing by a scale factor The equation is Result Reading OFFSET SCALE Where Reading is any reading OFFSET is the value stored in the OFFSET register default 0 notice that the first reading is not stored in OFFSET as it was for the NULL operation SCALE is the value stored in the SCALE register default 1 Notice that the default values do not change the reading they subtract 0 and divide by 1 You can change the values in the OFFSET register or the SCALE register using the SMATH command The following program uses the real time scale operation to divide each of 20 readings by 2 The default value of 0 is left in the OFFSET register so no subtraction is done before the readings are scaled 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 20 DIMENSION ARRAY FOR 20 READINGS 30 OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 TRIG SYN 40 OUTPUT 722 NRDGS 20 20 READINGS PER TRIGGER 50 OUTPUT 722 MATH SCALE ENABLE REAL TIME SCALE OPERATION 60 OUTPUT 722 SMATH SCALE 2 WRITE 2 TO SCALE REGISTER 70 ENTER 722 Rdgs SYN EVENT ENTER SCALED READINGS 80 PRINT Rdgs PRINT SCALED READINGS 90 END The following program uses the post process scale operation to subtract the value of from each read
69. You can also use the HOLD parameter to prevent the measurement method from changing to random should level triggering not occur within certain time limits The time limits are determined by the AC bandwidth ACBAND command setting SSRC source mode source The source parameter choices are Numeric source Query Parameter Equiv Description EXT 2 Synchronize to external input on the rear panel Ext Trig connector LEVEL 7 Synchronize to a voltage Level LEVEL command gt on the input signal using the slope specified by the SLOPE command For synchronous ACV or ACDCYV the level triggering voltage LEVEL command and the slope SLOPE command are determined automatically and cannot be specified Power on source LEVEL Default source LEVEL mode The mode parameter applies only to synchronous ACV or ACDCV The choices are Numeric mode Query Parameter Equiv Description AUTO 1 For synchronous AC or ACDCV SETACV SYNC using level triggering default mode if the input signal is removed during a reading and does not return within a certain amount of time the measurement method changes to random so that the reading can be completed After the reading the measurement method returns to SYNC HOLD 4 The measurement method will not automatically change from synchronous to random when the input signal is removed The time limit for synchronous AC or ACDCV is determined by the bandwidth specified using
70. You can always read the string using the CALSTR command regardless of the security mode Refer to the SECURE command for information on securing and unsecuring the calibration RAM Query Command The CALSTR query command returns the character string from the multimeter s calibration RAM This is shown in the second example below e Related Commands CAL CALNUM SCAL SECURE CALSTR OUTPUT 722 CALSTR CALIBRATED 04 02 1987 CALSTR 10 DIM AS 80 DIMENSION STRING VARIABLE 20 OUTPUT 722 CALSTR READ THE STRING 30 ENTER 722 AS ENTER STRING 40 PRINT AS PRINT STRING 50 END Compress Subprogram Removes the ASCII text of a specified subprogram previously stored in memory This saves memory space but removes the subprogram from continuous memory the subprogram will be destroyed when power is removed COMPRESS name Subprogram name A subprogram name may contain up to 10 characters The name can be alpha alphanumeric or an integer in the range of 0 to 127 Refer to the SUB command for details Power on name none Default name none parameter required e To avoid memory fragmentation compress each subprogram before downloading other subprograms e You cannot store the COMPRESS command as part of a subprogram 166 Chapter 6 Command Reference CONT CSB Syntax Remarks Example Syntax Remarks CONT e Related Commands CALL CONT DELSUB PAUSE SCRATCH SUB SUBEND Example The fol
71. ato NPLC 1 are subject to potential 1 16 6 ms 7 5 60 29 4 noise pickup Care must be taken 10 0 166 s 7 5 6 3 to provide adequate shielding and 100 7 5 36 min 18 min guarding to maintain measurement accuracies Measurement Consideration 6 Aperture is selected independent Keysight recommends the use of PTFE cable of line frequency LFREQ These or other high impedance low dielectric apertures are for 60 Hz NPLC values where 1 NPLC 1 LFREQ For 50 Hz Maximum Input and NPLC indicated aperture will increase by 1 2 and reading rates absorption cable for these measurements Rated Non will decrease by 0 833 Input Destructive DE oe a For OFORMAT SINT HI to LO 1000 V pk 1000 V pk HI amp LO Sense to LO 200 V pk 350 V pk LO to Guard 200 V pk 350 V pk Guard to Earth 500 V pk 1000 V pk Temperature Coefficient Auto Zero off For a stable environment 1 C add the following error for AZERO OFF ppm of Range C Range Error Range Error 10 Q 50 IMQ 1 1009 50 10 MQ 1 1 kQ 5 100 MQ 10 10kQ 5 1 GQ 100 100 kQ 1 3 DC Current DC Current DCI Function Maximum Shunt Burden Temperature Coefficient Range Full Scale Resolution Resistance Voltage ppm of Reading ppm of Range C Without ACAL With ACAL a 100 nA 120 000 1 pA 545 2kQ 0 055 V 10 200 2 50 1pA 1 200000 1pA 45 2 KQ 0 045 V 2 20 2 5 3 10 pA 12 000000 1pA 5 2 KQ 0 055 V 10 4 2 1 100 pA 120 00000 10pA B
72. be used to speed throughput by disbling the multimeter s input protection algorithm and some syntax and error checking algorithms With these algorithms disabled the multimeter can change to a new measurement configuration faster than it can with them disabled Refer to the DEFEAT command in Chapter 6 for details and a CAUTION statement concerning its use The PRESET FAST command disables many functions that slow the reading rate and configures the multimeter for fast reading transfer to memory and to the GPIB Table 4 3 shows the speed related commands executed by PRESET FAST and the reason for executing each Chapter 4 Making Measurements 103 104 Table 22 Commands Executed by PRESET FAST Command Reason DCV 10 Selects DC voltage measurements on the 10V range which disables autorange The autorange function samples the input before each reading taking more time per reading than readings made on a fixed range The disadvantage of a fixed range is lower resolution for signals that are less than 10 of full scale and the possibility of an overload condition for readings greater than full scale AZERO OFF With autozero enabled a zero measurement is made following each reading for DC measurements only which increases the time per reading DISP OFF The time required for the multimeter to update its display slows the reading rate MATH OFF Any enabled real time math operation s slow the reading rate If you must
73. command and the digits of resolution is Digits of Resolution Power Line Cycles NPLC command DCI ACI ACDCI Reference Reference Frequency DCV OHM ACV Frequency LFREQ 50HZ F ACDCV LFREQ 60HZ 4 5 4 5 4 5 0 000030 0 000025 By 5 5 5 5 000036 000360 000030 000300 6 5 6 5 6 5 000366 030000 000305 025000 7 5 7 5 6 5 030006 1 025005 1 8 5 7 5 6 5 2 1000 2 1000 Analog measurement method only SETACV ANA command For all ranges except the 10Q OHM F range and the 100mV DCV range The 10Q OHM F range has a maximum of 6 5 digits and the 100mV DCV range has a maximum of 7 5 range Remarks For the ACV and ACDCV SETACV ANA method only ACT ACDCI DCI DCV OHM and OHMF measurement functions resolution is determined by the A D converter s integration time The integration time has no effect on FREQ or PER For sampled ACV or ACDCV SETACV SYNC or SETACV RNDM the integration time is selected automatically and the specified resolution is achieved by varying the number of samples taken For direct or sub sampled digitizing the integration time is fixed and cannot be changed Since the NPLC and APER commands both set the integration time executing either will cancel the integration time previously established by the other The RES command or the resolution parameter of a function command or the RANGE command can also be used to indirectly select an integration time An Cha
74. command followed by the LEVEL occurrence of the LEVEL event one reading is taken per sample event until the specified number of readings are completed The trigger arm event then becomes HOLD SGL LEVEL SYN LINE Illegal SGL LINE AUTO EXT TIMER After executing the TARM SGL command followed by the LINE power line voltage crossing zero volts one reading is taken per sample event until the specified number of readings are completed The trigger arm event then becomes HOLD SGL LINE SYN LEVEL Illegal SGL SGL Any Illegal 1 The LEVEL event occures when the specified voltage is reached on the specified slope of the input signal The LEVEL trigger event or sample event can only be used for DC voltage or direct sampled measurements 2 The output buffer must be empty and reading memory must be OFF or empty for the SYN event to occur 3 The input buffer must be enabled or you must suppress cr If when sending the TARM SGL command 90 Chapter 4 Making Measurements Table 21 Event Combinations Trigger Arm Trigger Sample Description Event Event Event SGL SYN SYN After executing the TARM SGL command followed by the controller requesting data which satisfies both SYN events the first reading is taken One reading is then taken per SYN event until the specified number of readings are completed The trigger arm event then becomes HOLD SGL SYN AUTO EXT TIMER After executing the TARM
75. control the resolution 10 OUTPUT 722 NPLC 0 SETS PLCS TO MINIMUM 20 OUTPUT 722 DCV 6 SELECTS DC VOLTS 10V RANGE 30 OUTPUT 722 RES 001 100pV OF RESOLUTION ON THE 10V RANGE 40 END In the following program line 10 sets the number of PLCs to 1000 This corresponds to maximum resolution 7 5 digits and prevents the RES command in line 30 from affecting the measurement The requested resolution in line 30 is 10mQ However because of line 10 the actual resolution is 100uQ 10 OUTPUT 722 NPLC 1000 SETS PLCS TO MAXIMUM 20 OUTPUT 722 OHM 153 SELECTS 2 WIRE OHMS 1kQ RANGE 30 OUTPUT 722 RES 001 REQUESTS 10mQ RESOLUTION 40 END Allows you to set the multimeter to the power on state without cycling power Syntax RESET Remarks The RESET command does the following 226 Chapter 6 Command Reference Example Aborts readings in process Clears error and auxiliary error registers RESET Clears the status register except the Power on SRQ bit bit 3 Clears reading memory In addition the RESET command also executes these commands ACBAND 20 2E6 MFORMAT SREAL AZERO ON MMATH OFF DCV AUTO NDIG 7 DEFEAT OFF NPLC 10 DELAY 1 NRDGS 1 AUTO DISP ON OCOMP OFF EMASK 32767 all enabled OFORMAT ASCII QFORMAT NORM END OFF RATIO OFF EXTOUT ICOMP NEG RQS 0 FIXEDZ OFF SETACV ANA FSOURCE ACV SLOPE POS INBUF OFF SSRC LEVEL AUTO LEVEL 0 AC SWEEP 100E 9 1024 LFILTER OFF TARM AUTO LFREQ line fr
76. eseeeeee 18 Power Cords swesiecesscageshicsnliceiiauneauhee 18 Connecting the GPIB Cable n se 19 The GPIB Address iriennerien 20 Mounting the Multimeter ceeeeeeeereeeeeeee 20 Installation Verification ccceeeeeeseeeeeeeee 21 Maintenances eececceseeecesceeeeeseesecceeeeeeeeeaeeeeeneeeees 21 Replacing the Line Power Fuse eseeee 21 Replacing a Current Fuse cccceeseeceereees 21 Repair SCTViCE sracsescniescaseiessscedesccnedsvstsecedeneedtoss 22 Chapter 2 Getting Started Introd ction eds seacse esse dass sanrcateearena i ai e 25 Before Applying Power ccccssseeseeeeeeeseeneeerees 25 Applying Power 0 cceeeecceseeseeseeeecesceseeneeereeaeenee 25 Power On Self Test 0 0 cccccecceecceseeceeeeceteeeeaeees 25 Power On State ooo ce ceeceseseeeecsesseeeeens 25 The Display secsacueserdsovavsovevesavcasseaveestsieeddabeeetene 26 Operating from the Front Panel cesses 27 Making a Measurement csceeceeseeseeeeeteeeee 28 Changing the Measurement Function 28 Autorange and Manual Ranging c 29 DelfeV St meistarinn an a e eE EEn EEA 30 Reading the Error Register 0 ececcesseseeereeeee 31 Resetting the Multimeter 2 0 0 0 eeeeeeeeeseeeeees 32 Using the Configuration Keys cseeeeeeee 32 Using the MENU Keys ccccecseeseeteeeteeeeeeeees 36 Query Commands cecccececeseeeeeeereeeteeeeeeaees 37 Display Control 0 eeeeeeceseeseee
77. event becomes HOLD which stops readings and removes the multimeter from the high speed mode After removing some or all of the readings from memory you can resume measurements by changing the trigger arm event TARM command When not in the high speed mode when you fill memory in the FIFO mode the stored readings remain intact and new readings are not stored In the LIFO mode when reading memory becomes full the oldest readings are replaced with the newest readings regardless of whether in the high speed mode or not When the controller requests data from the multimeter and its output buffer is empty in the LIFO or FIFO mode a reading is removed from memory and sent to the controller This is the implied read method of recalling readings In the LIFO mode the most recent reading is returned In the FIFO mode the oldest reading is returned The reading storage mode LIFO or FIFO is important only when you are using the implied read method of recalling readings The reading storage mode has no effect on readings recalled using the RMEM command e Use the MFORMAT command to specify the memory format SINT DINT ASCII SREAL or DREAL e Executing the RMEM command sets reading memory to OFF You must execute MEM CONT MEM FIFO or MEM LIFO to reenable reading memory after executing RMEM Query Command The MEM query command returns the present memory mode Refer to Query Commands near the front of this chapter for more info
78. execution the Ready Bit is set to 1 indicating that the 3458A is ready to receive additional commands The CALL command may also be used in a subprogram to call another subprogram This provides the expanded capability of nested subprograms When using nested subprograms the calling subprogram is suspended so that only one subprogram is running at a time Subprograms can be nested up to 10 deep The PAUSE command pauses the most recent subprogram executed with the CALL command Once a subprogram has been paused you must execute the CONT continue command to resume execution The CONT command allows the subprogram to continue running to completion starting with the next command after the PAUSE command The 3458A will generate an error if you attempt to execute the CONT command when a subprogram is not paused The PAUSED query command returns a 1 if the subprogram is currently paused or a 0 if the subprogram is running or finished running The following program shows how to use the PAUSED command 10 OUTPUT 722 20 OUTPUT 722 30 ENTER 722 A 40 IF A 1 THEN PRINT SUBPROGRAM IS PAUSED 50 IF A 0 THEN PRINT SUBPROGRAM IS NOT PAUSED 60 END RUN DMM_CONF PAUSE PAUSED The GPIB CLEAR command see Appendix B aborts execution of a subprogram executed with the CALL command This returns control to the GPIB command input buffer or the front panel keyboard A subprogram will continue to execute until it reaches the
79. for both memory and GPIB output single integer SINT double integer DINT IEEE 728 four byte single real SREAL IEEE 728 eight byte double real DREAL and ASCII The fastest format for data transfer is the single integer This is a 16 bit integer format so range information must be known to determine the placement of the decimal point In addition it only has 16 bits hence if more than 4 1 2 digits is desired from a measurement one of the other formats must be used The next highest speed format is double integer This is a 32 bit integer format so except for the range information all the measurement data is transferred SREAL transfers all the data including the range information in four eight bit bytes The controller must be able to accept this format and translate it into ASCII to be able to use it Finally the slowest format is the ASCII format Basically each reading needs eighteen bytes of data plus carriage return line feed terminator to transfer into the controller Many times it is important to acquire the data quickly but the actual transfer of the data can be comparatively slow In this case the ideal combination of data formatting is SREAL for measurements taken into memory and ASCII output to GPIB The DINT and SINT formats are accepted directly without need for additional translation by the HP 9000 Series 200 300 computers Almost any controller can accept ASCII formats In programs where functions or ranges are change
80. for tables showing the ranges for each measurement function Configuring for DC or Resistance Measurements This section describes how to configure the multimeter for making DC voltage DC current and 2 wire or 4 wire resistance ohms measurements DC Voltage The multimeter measures DC voltage on any of five ranges Table 12 shows each DC voltage range and its full scale reading which also shows the maximum number of digits for the range Table 12 also shows the maximum resolution and the input resistance for each range Resolution is a function of the specified integration time refer to Setting the Integration Time later in this section for more information Figure 11 shows the front terminal connections for all types of voltage measurements In the power on PRESET NORM states DC voltage measurements are selected You can also specify DC voltage measurements using the DCV command For example to specify 54 Chapter 3 Configuring for Measurements DC voltage measurements on the 1 V range send OUTPUT 722 DCV 1 Table 12 DC Voltage Ranges DCV Range Full Scale Reading Maximum Resolution Input Resistance 100mV 120 00000mV 10nV gt 10GQ 1V 1 20000000V 10nV gt IOGQ 10V 12 0000000V 100nV gt IOGO 100V 120 000000V 1uV 10MQ 1000V 1050 00000V 10uV 10MQ With FIXEDZ OFF With FIXEDZ ON the input resistance is fixed at 1OMQ Refer to Fixed Input Resistance later in this chapter for more information
81. high speed transfer from 108 sending samples to 144 using reading 94 using subprogram 71 MENU 36 197 menu key 36 MENU keys 36 INDEX 367 Menu scroll 36 Methods digitizing 129 MFORMAT 198 MMATH 199 Mode high speed 102 MORE INFO annunciator 27 display 39 MORE INFO annunciator 27 Mounting bench top 20 multimeter 20 rack 20 MRNG annunciator 27 MSIZE 202 Multimeter installing the 17 mounting the 20 presetting the 52 resetting the 32 Multiple commands 152 parameters 35 readings 83 trigger arming 84 N NDIG 203 Nested subprograms 73 NPLC 204 NRDGS 206 rdgs Trig key 33 NULL 117 Number of devices GPIB maximum 20 Z Numeric parameters 34 O OCOMP 208 Offset compensation 62 105 OFORMAT 209 OHM 213 OHM example high speed 105 OHM key 29 OHMF 213 OHMF example high speed 106 OHMF key 29 Ohms 2 Wire 57 4 Wire 57 Operating from remote 42 OPT 213 Options and accessories 16 Output format using DINT 99 using SINT 99 using the DREAL 101 using the SREAL 101 OUTPUT statement 42 Output termination 99 Overlay installing the keyboard 41 Overload indication 96 99 P Parameter selecting a 33 Parameters 152 defaulting 152 exponential 35 multiple 35 numeric 34 Pass fail 123 PAUSE 214 PER 215 example fast 107 PER key 29 Percent 120 Period 65 Power applying 25 cable 17 consumption 17
82. is a variable name which acts as the loop counter The initial value parameter and final_value parameter may be numbers numeric variables or numeric expressions The optional step_size parameter may be a number or numeric expression which specifies the amount the loop counter is incremented for each pass through the loop A negative value for step_size decrements the loop counter The program segment is repeatedly executed until the loop counter exceeds the final_value 10 OUTPUT 722 SUB DMM CONE 20 OUTPUT 722 NRDGS 100 30 OUTPUT 722 TRIG SGL 40 OUTPUT 722 INTEGER I 50 OUTPUT 722 FOR I 1 TO 100 60 OUTPUT 722 ENTER A I 70 OUTPUT 722 NEXT I 80 OUTPUT 722 SUBEND JOET 100 OUTPUT 722 CALL DMM CONE 110 END The WHILE command defines a loop which is repeated as long as the specified numeric expression is true The syntax for the WHILE command is shown below WHILE expression program segment ENDWHILE The WHILE operation depends on the result of a test performed at the start of the loop Ifthe test is true not equal to zero the program segment between the WHILE and ENDWHILE statements is executed and a branch is made back to the WHILE statement If the test is false equal to zero program execution continues with the statement following the ENDWHILE statement 10 OUTPUT 722 SUB DMM CONE 20 OUTPUT 722 INTEGER I 30 OUTPUT 722 LET I 1 40 OUTPUT 722 NRDGS 10
83. lets your 3458A and a HP 9000 Series 200 300 computer take measurements up to 50 000 Samples s and present the data to the computer display at a refresh rate up to 5 s In effect the combination gives you a very high resolution single channel oscilloscope of 12 MHz bandwidth g Setup_dig if The Wave Form Analysis Library also lets you compare a previously captured wave form with limits on the measurements to the input signal Several utility functions are also provided with the Wave Form Analysis Library Format which formats the output display in engineering units Intrpo which performs a linear interpolation between sample points Sinc which performs a sinc function interpolation between sample points for signals captured near the Nyquist limit and Warn58 which prints error and warning messages on the computer CRT or printer As an example consider how the Wave Form Analysis Library can be used to capture an AM modulated signal to extract the carrier the modulation frequency and the depth of modulation First the main program must be written to call the library subprograms The main program is a block of program code that controls and invokes the subprograms in the order necessary to solve the measurement problem The main program can be short or long depending on the needs of the measurement task Part of a main program is shown in below This program captures a wave form using
84. n E A 235 SSAC SSD siniraan 236 SSPARM cesta aston errnit anA 239 SSRO ooann erisa ea R 239 SSTA Wl Sane ee rte eeaeee a E ANAE ERNES 243 STB EEE 244 SUB ee E E S 245 SUBEND arosa a E A EE 247 SWEEP easan vent dasveatiunr cgesuieastivhenvonts 247 A a EE E E E A A A 250 TARM sinenion en Maaete Gated 250 TBUEF saci ntueaieetien aniisi iiaei 252 TEMP nesini 253 TERM cbcuasSdatruactustbin ti gtan nenene 253 TES P aitsajeessapareceeisanitaiamiesocisensamiennsageananan 254 TIMER passisciuss tecsesnsevieaceataae tivisaantctactscakeaseae 254 TONE cruca nae E des tevanseateetonsseasess 255 TRIG iiae aT EE euetae ca tavieveeeds 255 Chapter 7 BASIC Language for the 3458A ntrod ction sessisssiisisresonessssensiiiisess 261 How It Works eceecceceeseeeeeeceececeeeeeaeeeeceaeeaeeanens 261 BASIC Language Commands ceeeeeeeeeees 262 Variables and Arrays ccccecccesteesteeseeeteeeees 262 Contents 9 Math Operations 0 0 0 ceeceseecceeeeeeeeeeeeeeseees 262 Subprogram Definition Deletion 6 263 Subprogram Execution Commands 263 Looping and Branching cceeceeteeees 263 Binary Programs c cecccesseesseesteeeteeeteeeeeeees 263 New Multimeter Commands ccccecseeseeteees 264 3458A BASIC Language Example Program 265 Variables and Arrays ccccccesecseceteeeseeeeeeeseeees 266 Type Declarations ccccecseesseeseeeteeeteeeeeeees 266 Type Conversions
85. of a positive argument to the base 10 Three trigonometric functions are provided in the 3458A The trigonometric functions are shown in the following table Function Argument Meaning X in radians SIN X Sine of argument COS X Cosine of argument ATN X Arctangent of argument The 3458A has four logical functions AND inclusive AND OR inclusive OR EXOR exclusive OR and NOT logical inverse The first three functions compare the two arguments and return either a 0 ora 1 based on the respective truth table Any non zero value positive or negative in an argument is considered a logical 1 Only zero is treated as a logical o The logic function commands have the following syntax The truth tables for the four functions are shown below argument AND argument argument OR argument argument EXOR argument NOT argument A AND B AORB AEXORB NOTA NOTB A B 0 0 0 0 0 1 1 0 1 0 1 1 1 0 1 0 0 1 1 0 1 1 1 1 1 0 0 0 The 3458A provides seven binary functions These can help in digital pattern generation When using the binary functions argument values X and Y of real variables are rounded to integers in the range 32768 to 32767 The binary functions are shown in the table below Function Argument Meaning BINAND X Y Bit by bit logical AND of the arguments BINCMP X Bit by bit binary complement of the argument BINEOR X Y Bit by bit logical Exclusive OR
86. of the arguments BINIOR X Y Bit by bit logical Inclusive OR of the arguments BIT X position Returns 0 or 1 representing the logic value of the specified bit of the argument The bit position is in the range 0 Isb to 15 msb Chapter 7 BASIC Language for the 3458A 271 Math Hierarchy Math Errors Making Comparisons 272 Work Function Argument Meaning ROTATE X displacement Returns an integer obtained by rotating the argument a specified number of positions with bit wraparound SHIFT X displacement Returns an integer obtained by rotating the argument a specified number of positions without bit wraparound If the displacement is positive rotating or shifting is toward the least significant bit If the displacement is negative rotating or shifting is toward the most significant bit The 3458A evaluates parenthetical expressions before evaluating any math functions outside of parentheses If two or more operations of the same priority are in the expression the hierarchy is from left to right Highest Priority Parentheses Functions SIN COS etc Exponentiation 4 MOD DIV Lowest Priority Relational Operators lt gt lt gt etc logical operators AND OR etc When evaluating a math expression the following errors may occur The 3458A treats math errors just like any other execution errors Refer to chapter 3 for more information on handling erro
87. power line cycles Auto AZERO Enables or disables the autozero function ero Offset ocomP Enables or disables offset compensation for 2 or 4 wire resistance measurements TRIG Specifies the trigger event N Rdgs NRDGS Selects the number of readings per trigger event rig Come fe Muk and the sample event Recall RSTATE Recalls a previously stored state from memory State Store SSTATE Stores the multimeter s present state in memory ate This is the command header for the trigger command Notice the multimeter automatically placed a space after the command header Selecting a Parameter For parameters that have a list of choices non numeric parameters you can use the up and down arrow keys to review the choices Press aa The display shows Chapter 2 Getting Started 33 Default Values Numeric Parameters 34 Chapter 2 Getting Started When using the up or down arrow keys if you step past the last parameter choice a wraparound occurs to the other end of the menu Suppose you want to suspend triggering Press the up or down arrow key until the display shows You have now changed the trigger event from auto power on state to HOLD which causes the multimeter to stop taking readings Triggering is discussed in detail in Chapter 4 Most parameters have a default value A default value is the value selected when you execute a command but do not specify a value For example the default value f
88. producing more bits of resolution than can be accommodated by the SINT format the least significant bit s are discarded Whenever using the SINT output memory format with integration times gt 10 8us the multimeter must convert the data coming from the A D converter and cannot maintain the high speed mode You should use the DINT memory output format which is compatible with the high speed mode when the integration time is gt 10 8ps Whenever making measurements using the TIMER sample event or the SWEEP command autorange is disabled You can use the range selected by PRESET DIG 10V range or specify the range as the first parameter of the DCV or RANGE command max_input parameter The max_input parameters and the ranges they select are Chapter 5 Digitizing 135 136 DCV Example Chapter 5 Digitizing max _input Parameter Selects Range Full Scale 0 to 12 100mV 120mV gt 12 to 1 2 1V 1 2V gt l 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to 1E3 1000V 1050V The multimeter s triggering hierarchy trigger arm event trigger event and sample event applies to DCV digitizing Refer to Chapter 4 for more information on the triggering hierarchy For DCV digitizing you can use either the TIMER sample event and the NRDGS 2 TIMER command or the SWEEP command The NRDGS and SWEEP commands are interchangeable the multimeter uses whichever command was specified last When using the SWEEP command
89. readings and removes the multimeter from the high speed mode After removing some or all of the readings from memory you can resume measurements by changing the trigger arm event TARM command In the LIFO mode when reading memory becomes full the oldest readings are replaced with the newest readings regardless of whether in high speed mode or not In the high speed mode the input buffer is temporarily disabled while readings are being made Also if END ALWAYS was specified specifies the GPIB EOI mode the EOI mode changes to END ON while the readings are being made Following completion of the readings the input buffer mode and the EOI mode return to that previously specified In the high speed mode the multimeter will respond only to the GPIB CLEAR command Device Clear If for some reason you must remove the multimeter from the high speed mode send the following CLEAR 722 The CLEAR command suspends measurements which removes the multimeter from the high speed mode Refer to Appendix B for more information on the GPIB CLEAR command The PRESET FAST command executes a series of commands that configure for fast readings In addition the reading rate is affected by the integration time and or resolution triggering setup delay time AC bandwidth for AC measurements only and for resistance measurements only the offset compensation mode In addition to the commands discussed in this section the DEFEAT command can
90. rear bezel 10 Remove the top cover Pull the cover toward the rear and away from the instrument 11 Turn the 3458 over so its top sits on your workbench Remove the bottom cover Pull the cover toward the rear and away from the instrument Leave the instrument in its present position 312 Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches 3 LEFT SIDE HANDLE STRAP SCREW 4 LEFT SIDE HANDLE STRAP Figure 36 3458 Left side COVER GROUND SCREW Figure 37 Covers ground screws Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches 313 6 REAR BEZEL SCREWS EJ REAR BEZEL SCREWS Figure 38 3458 Rear view Guard Pushrod If you DO NOT wish to lockout the Guard switch continue with the next Removal paragraph Procedure 1 Refer to Figure 39 Use the TX 10 Torx driver to remove the bottom shield screw Then remove the shield Pull the shield toward the rear of the instrument until the shield retainers line up with the slots in the shield Lift the shield off 2 Refer to Figure 40 Locate the pushrod for the Guard switch Pull the pushrod off You may need to pry the pushrod loose with a small flat blade screwdriver Set the switch in the position it is to be used 3 Refer to Figure 39 Replace the bottom shield Line up the slots on the shield with the shield retainers Then push the shield toward the front of the instrument until the shield screw hole li
91. rejection ECMR on the input terminals selected by the Terminals switch assuming the Guard switch is in the Open out position For non guarded measurements depress the Guard switch TO LO position and do not connect the Guard terminal to the measurement source In the TO LO position the Guard switch internally connects the Guard terminal to the LO Input terminal on the terminals selected by the Terminals switch This configuration provides reduced ECMR The specifications in Appendix A shows the ECMR for guarded measurements We recommend high impedance low dielectric absorption cables for all measurement connections In the multimeter s power on state the trigger arm trigger and sample events are set to AUTO these events are discussed in detail in Chapter 4 This causes the multimeter to continuously take readings Prior to configuring the multimeter for measurements you should suspend readings Suspending readings decreases the amount of time required for configuration and prevents the possibility of undesired readings being placed in reading memory or the GPIB output buffer You can suspend readings by presetting the multimeter discussed next or by setting the trigger arm or trigger event to HOLD as follows OUTPUT 722 TARM HOLD or OUTPUT 722 TRIG HOLD After configuring the multimeter you can enable measurements by changing the trigger arm or trigger event from HOLD to some other event Refer to Chapter 2 for more infor
92. resolution specified by line 20 is 6V x 0000167 100uV 10 OUTPUT 722 NPLC 0 SETS PLCS TO MINIMUM 20 OUTPUT 722 FUNC DCV 6 00167 SELECTS DC VOLTS 6V MAX 30 END 100pV RESOLUTION In the following program line 10 sets the number of PLCs to 1000 This corresponds to maximum resolution 7 5 digits and prevents _ resolution in line 20 from affecting the measurement The requested resolution from line 20 is 10uQ However because of line 10 the actual resolution is 100uQ 10 OUTPUT 722 NPLC 1000 SETS PLCS TO MAXIMUM 20 OUTPUT 722 FUNC OHM 1E3 001 SELECTS 2 WIRE OHMS 30 END 1kQ MAX 10mQ RESOLUTION ID Syntax Remarks Example Identity Query The multimeter responds to the ID command by sending the string HP 3458A This feature allows the GPIB controller to locate the multimeter by its address ID e Related Commands ADDRESS QFORMAT 10 OUTPUT 7223 1D RETURNS RESPONSE 20 ENTER 722 AS ENTERS RESPONSE INTO THE COMPUTER S AS VARIABLE 30 PRINT AS PRINTS RESPONSE 40 END INBUF Syntax Input Buffer Enables or disables the multimeter s input buffer When enabled the input buffer temporarily stores the commands it receives over the GPIB bus This releases the bus immediately after a command is received allowing the controller to perform other tasks while the multimeter executes the stored command INBUF control 186 Chapter 6 Command Reference ISCALE control The control parameter cho
93. room for those being entered The Display Window keys left and right arrow keys allow you to view the entire line by scrolling it left or right The Display Window keys can also be used to view long strings such as error messages the calibration string CALSTR command and user defined key definitions discussed later For example press eye Je JC JC J JC Je Je The display shows By pressing the left arrow key you can view the first part of the command while scrolling the last part off the right side of the display Now by pressing the right arrow key you can view the last part of the command and scroll the first part off the left side of the display Think of the display as a window you can move to the left or right using the MORE INFO Display Digits Displayed Note Recall arrow keys In addition to scrolling the display left and right the Display Window keys allow you to view additional display information when the display s MORE INFO annunciator is illuminated For example access and execute the SETACV RNDM command from the alphabetic command menu Now press the front panel ACV key Notice that the multimeter s MORE INFO annunciator is illuminated This means there is more information available than is being displayed Press The present AC voltage measurement method SETACV RNDM is displayed At this point reset the multimeter to return it to the power on state by pressing Reset a
94. routing the signal for either the Analog to Digital ADC or the track and hold Auto zero eliminates input offset errors but the residual error does propagate This section is the low frequency section of the 3458A Hence depending on the range the signal is routed through a low pass filter the input amplifier before being presented to the ADC Quantization error is the fundamental irreducible error associated with the perfect quantizing of a continuous analog signal into a finite number of digital bits Hence the resolution of the ADC has a direct impact on your ability to measure the input wave form in detail Some limitations may be overcome by window amplifiers that will allow the signal s detailed examination in the presence of large offsets but the introduction of the amplifier adds error to the measurement that is not necessary for high resolution ADCs Missing code may only manifest itself at high speed The most common cause of missing code is dielectric absorption DA the polarization of dipoles in the insulating material surrounding the conductor Careful design can eliminate this problem but DA can cause measurements to have a memory of previous measurements If sufficient settling time is given to the ADC the problem falls below the quantization level Missing code coupled with quantization error results non linearity of the ADC This occurs in two forms differential and integral non linearity Differential nonline
95. space becomes available When space is available the remaining characters are accepted into the input buffer and the bus is released When using the input buffer it may be necessary to know when all buffered commands have been executed The multimeter provides this information by setting bit 4 ready for instructions in the status register discussed next If the status register is properly enabled it drives the GPIB s SRQ service request line true Your controller will acknowledge this if previously programmed to accept SRQ as an interrupt Using the Status Register The status register monitors the following multimeter status information Chapter 3 Configuring for Measurements 75 Subprogram complete High or low limit exceeded SRQ command executed e Power turned on Ready for instructions Error Service requested e Data available When one of these events occurs it sets a corresponding bit in the status register The following list defines the meaning of each bit in the status register Bit 0 weight 1 Subprogram Complete a stored subprogram has been executed Bit 1 weight 2 High or Low Limit Exceeded one or more readings have exceeded the high low limits specified for the Pass Fail math operation This bit applies to both real time and post process math See Pass Fail in Chapter 4 Bit 2 weight 4 SRQ Command Executed the multimeter s SRQ command has been executed Bit 3 weight
96. the display or to clear the display DISP control message The control parameter choices are Numeric control Query Parameter Equiv Description OFF 0 Displays message if included if no message dashes are displayed inactivates all annunciators except ERR readings are no longer displayed and the display is not updated except to service front panel keystrokes and query commands ON 1 Normal power on mode display operation MSG 2 Displays message annunciators activated CLR 3 Clears the display Chapter 6 Command Reference 171 DSAC DSDC message Remarks Examples DSAC DSDC Syntax max _input Power on control ON Default control ON The message parameter is the message to be displayed The message may contain spaces numerals lower or upper case letters and any of the following characters 148 amp s lt gt _ e You must enclose a message in quotation marks only if it contains a space comma or semicolon Either single or double marks or may be used the beginning and ending marks must match A message may contain up to 75 characters quotes enclosing the message are not counted as characters e Query Command The DISP query command returns the currently specified control parameter Refer to Query Commands near the front of this chapter for more information Related Commands NDIG The following command causes the multimeter to display the message TIME O
97. the following Installation 1 Refer to Figure 43 Turn the instrument so its front faces you Procedure 2 Locate the holes for the Front Rear terminal and Guard switches 3 Locate the little square covers that came in the switch lockout kit as shown in Figure 43 4 Line up the tabs on the covers with the top and bottom sides of either the Front Rear Terminal or Guard switch hole 5 Squeeze the tabs on the cover together and push the cover all the way into the switch hole Lock it in place 6 Do the same in steps 4 and 5 for the other switch hole if necessary 316 Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches FRONT REAR SWITCH PUSHROD Figure 42 Front rear terminal switch and pushrod location N Sense Input 4 Wire aires Reon 7 11 FRONT REAR SWITCH LOCKOUT COVER UF Clear el GUARD SWITCH LOCKOUT COVER Recall Enter peek 1A 250V All Term 1686VpK Max tA Figure 43 Switch covers installation Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches 317 Covers Installation Do the following Procedure i 2 Turn the 3458 over so its top sits on your workbench Install the bottom cover by placing it into the slots of the instrument side castings Then push the cover toward the front of the instrument into the front panel bezel Turn the 3458 over so the bottom sits on your workbench Install the top co
98. the sample event is automatically set to TIMER Aperture time is the time when the multimeter is actually sampling the input signal For direct and sub sampling using the track and hold the aperture time is fixed at 2ns and cannot be changed For DCV digitizing the aperture time is equal to the A D converter s integration time and can be varied from 500ns to 1s The multimeter effectively averages the input signal during its aperture time An amplitude error is introduced when the signal is changing during the aperture time Table 27 shows the input signal frequencies where 3dB of amplitude error occurs for selected aperture times and the bits of resolution produced for these aperture times Table 27 Amplitude Error and Resolution vs Aperture Error 2ns 16 100MHz 500ns 15 400kHz ius 16 206kHz 3us 17 69kHz 6us 18 35kHz 100us 21 2kHz The following program takes 256 DC voltage samples at a rate of 100 000 samples per second and places them in reading memory using SINT format The samples are then transferred to the controller using the SINT output format The controller converts the samples from SINT format and stores the samples By deleting line 100 samples will be transferred directly to the controller instead of using reading memory However the controller and GPIB must be able to transfer samples at a rate of at least 200k bytes second or the multimeter will generate the TRIGGER TOO FAST error Refer to H
99. to be the null value you can write another value to the OFFSET register using the SMATH command You must wait however until after the first reading is made real time or recalled post process before changing the value A typical application of the NULL operation is in making more accurate 2 wire ohms measurements To do this select 2 wire ohms OHM command and short the ends of the test leads together Now enable the NULL operation The first reading taken the lead resistance is stored in the OFFSET register Connect the test leads to the unknown resistance to be measured The multimeter then subtracts the value in the OFFSET register from all subsequent readings until the math NULL operation is disabled This method is not as accurate as 4 wire ohms because the resistance of the test leads connected together probably will not be the same as when they are connected to the unknown resistance Also the resistance of the test leads is checked only once for a series of measurements and the test lead resistance may change The following program performs the real time NULL math operation on 20 readings After executing the NULL command the first reading is triggered by line 50 The value in the OFFSET register is then changed to 3 05 The 20 readings are triggered by line 90 and 3 05 is subtracted from each reading 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 DIM Rdgs 20 DIMENSION ARRAY FOR 20 READINGS OUTPUT 722 PRESET
100. to continue using autorange However you have two other ranging choices hold and manual ranging This choice allows you to shut off autoranging To do this let autorange choose a range and then press Hold me When you press the blue shift key the display s SHIFT annunicator illuminates The shifted keyboard functions are printed in blue above the keys Chapter 2 Getting Started 29 Manual Ranging Self Test Note 30 Chapter 2 Getting Started Notice the display s MRNG manual range annunciator is on This annunciator is on whenever you are not using autorange The second choice lets you manually select the range When the multimeter is in the measurement mode that is the multimeter is making and displaying measurements or the display is showing OVLD you can change the range by pressing the up or down arrow keys To go to a higher range press all By repeatedly pressing the up arrow key you can increment up to the highest range When you reach the highest range pressing the up arrow key no longer changes the range To go to a lower range press e By repeatedly pressing the down arrow key you can decrement down to the lowest range When you reach the lowest range pressing the down arrow key no longer changes the range To return to autoranging press Auto Ee When you applied power to the multimeter it automatically performed a limited power on self test Before you start making measurements
101. trigger 88 Burst complete 113 Bus sending readings across the 98 C Cable lengths GPIB 20 power 17 Cable connecting the GPIB 19 CAL 164 Calibration 48 CALL 164 CALNUM 165 CALSTR 165 Caps line fuse 21 switch lockout 311 Changing GPIB address 43 measurement function 28 Choices event 82 Clear key 31 38 Clearing the display 37 Coding two s complement binary 92 Combinations event 88 Command sending a remote 43 termination 152 Command PRESET FAST 103 Commands functional group 155 multiple 152 query 37 153 standard query 153 Compensation offset 62 105 COMPRESS 166 Compressing subprograms 73 Computers series 200 300 20 Configuration general 47 Configuration using the keys 32 Configuring A D converter 58 for AC measurements 62 for DC or resistance measurements 54 for fast readings 103 for ratio measurements 70 Connecting the GPIB cable 19 CONT 167 Continuous readings 82 Control display 37 Controller sending samples to the 144 Conventions language 152 Conversion analog RMS 64 random sampling 64 synchronous sampling 63 Cords power 18 CSB 167 Current AC 64 AC DC 64 Cycles specifying power line 59 D DB 120 DBM 121 DC current 55 DC or resistance measurements configuring for 54 DC voltage 54 DCI 168 example high speed 106 DCV 168 digitizing 134 example 136 example high speed 105 DCV key 29 DCV remarks 135
102. use actual values specified in seconds volts ohms etc instead of parameter choices For example the APER Chapter 6 Command Reference 153 Introduction command specifies integration time in seconds The range of values for this command is 500ns to 1s When you send the APER query command the multimeter responds with the actual value of integration time presently specified The QFORMAT query format command can be used to specify whether query responses will be numeric as shown above alpha or alphanumeric For example the following program changes the query format to ALPHA This causes the multimeter to return an alpha command header and an alpha response whenever possible as shown in the following program 10 OUTPUT 722 QFORMAT ALPHA 20 OUTPUT 722 AZERO 30 ENTER 722 AS 40 PRINT AS 50 END Typical response AZERO ON In the ALPHA query format commands that use actual values return an alpha command header and a numeric response For example a typical response to the APER query command is APER 166 667E 03 Many query commands can return both alpha and numeric responses For example the NRDGS query command returns two responses The first response is numeric and indicates the number of readings per trigger event The second response is alpha assuming QFORMAT ALPHA and indicates the specified sample event The following program executes the NRDGS query command and prints the responses 10 OUTPUT 722 NRD
103. your specific measurement need SETACV SYNC Synchronously Sub sampled Computed true rms technique This technique provides excellent linearity and the most accurate measurement results It does require that the input signal be repetitive not random noise for example The bandwidth in this mode is from 1 Hz to 10 MHz SETACV ANA Analog Computing true rms conversion technique This is the measurement technique at power up or following an instrument reset This mode works well with any signal within its 10 Hz to 2 MHz bandwidth and provides the_ fastest measurement speeds SETACV RNDM Random Sampled Computed true rms technique This technique again provides excellent linearity however the overall accuracy is the lowest of the three modes It does not require a repetitive input signal and is therefore well suited to wideband noise measurements The bandwidth in this mode is from 20 HZ to 10 MHZ Selection Table Best Repetitive Readings Sec Technique Frequency Range Accuracy Signal Required Minimum Maximum Synchronous Sub 1 Hz 10 MHz 0 010 Yes 0 025 10 sampled Analog 10 Hz 2 MHz 0 03 No 0 8 50 Random Sampled 20 Hz 10 MHz 0 1 No 0 025 45 Synchronous Sub sampled Mode ACV Function SETACV SYNC Temperature Coefficient Additional error beyond 1 C but within 5 C of last ACAL For ACBAND gt 2 MHz use 10 mV range temperature coefficient for all ranges Specifications apply
104. 0 50 OUTPUT 722 TRIG SGL 60 OUTPUT 722 WHILE I lt 100 70 OUTPUT 722 ENTER A I 80 OUTPUT 722 LET I I 1 90 OUTPUT 722 ENDWHILE 100 OUTPUT 722 SUBEND 110 120 OUTPUT 722 CALL DMM CONE Chapter 7 BASIC Language for the 3458A 279 IF THEN Branching 130 END The IF THEN command provides conditional branching within 3458A subprograms The syntax statements for the IF THEN command is shown below IF expression THEN program segment ELSE program segment ENDIF The ENDIF statement must follow the IF THEN statement somewhere in the subprogram ELSE is an optional statement but if used must appear before the ENDIF statement All commands after the IF THEN statement and before the ELSE and ENDIF statements will be executed if the expression evaluates to true not equal to zero If the expression is true execution continues with the program segment between IF THEN and ELSE Ifthe expression is false execution continues with the segment after ELSE In either case when the program segment is completed assuming there are no other loops or conditional branches program execution continues with the statement following the ENDIF statement 10 OUTPUT 722 SUB DMM CONE 20 OUTPUT 722 INTEGER I 30 OUTPUT 722 LET I 1 40 OUTPUT 722 NRDGS 100 50 OUTPUT 722 TRIG SGL 60 OUTPUT 722 IF I lt 100 THEN 70 OUTPUT 722 ENTER A I 80 OUTPUT 722 LET 1 1 1 9
105. 0 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 4 4 4 00 10 20 30 40 50 60 70 80 90 The following program uses the 3458A to calculate the mean throwing away the largest and smallest values Four BASIC language commands are used RMATHV LET REAL and OUTPUT l RMATHV Fills a variable with the present value of l a math register similar to RMATH OUTPUT Returns the value to the source from which the command was executed since the example called the I subprogram from the GPIB bus the value of AVG is sent over the bus LET and REAL Assign values to the specified variables l l DIM Rdgs 1 300 Dimension data array in computer ASSIGN Dvm TO 722 Set up GPIB address CLEAR Dvm OUTPUT Dvm RESET WAIT 0 5 li OUTPUT Dvm PRESET FAST OUTPUT Dvm OHM 1000 OUTPUT Dvm APER 167E 6 OUTPUT Dvm OFORMAT ASCII OUTPUT Dvm MEM FIFO OUTPUT Dvm NRDGS 300 TIMER Set up to acquire 300 readings OUTPUT Dvm TIMER 0 0002 5000 Rdgs sec sample rate OUTPUT Dvm SUB CALC MEAN Start of DMM subprogram OUTPUT Dvm REAL BIG SMALL AVG Dimension user variables OUTPUT Dvm MMATH STAT OUTPUT Dvm RMATHV MEAN AVG New DMM command OUTPUT Dvm RMATHV UPPER BIG New DMM command OUTPUT Dvm RMATHV LOWER SMALL New DMM command OUTPUT Dvm LET M AVG 300
106. 0 670 UTPUT 722 DCV 10 28 TO 33 NTER 722 A 1 O ve H UT 722 ACV 10 ACBAND 5000 NTER 722 A 34 UTPUT 722 DCV 10 35 TO 37 NTER 722 A 1 NEXT Exe_time TIMEDATE Exe_ time Dnld time 0 Tns_time 0 SUBEND SUB Integrat REAL Dnld_time Exe time Tns_time DIM A 37 Exe time TIMEDATE OUTPUT 722 PRESET OUTPUT 722 0OHM 1E4 NPLC 0 FOR I 1 TO 15 ENTER 722 A 1 NEXT OUTPUT 722 0HM 1E5 F 16 TO 23 ENTER 722 A 1 NEXT OUTPUT 722 OHMF 1E3 APER 20E 6 ENTER 722 A 24 E O E e E O F E N O E e F E Howo zyo O G a J gs H H O ve H W NTER 722 A 25 UTPUT 722 ACV 250 ACBAND 250 NTER 722 A 26 UTPUT 722 ACV 10 ACBAND 25000 NTER 722 A 27 UTPUT 722 DCV 10 NPLC 0 OR I 28 TO 33 NTER 722 A 1 EXT UTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 NTER 722 A 34 UTPUT 722 DCV 10 NPLC 0 OR I 35 TO 37 NTER 722 A 1 NEXT Exe_time TIMEDATE Exe_time Dnild_time 0 Tns_time 0 SUBEND SUB Delay REAL Dnld_time Exe time Tns_ time DIM A 37 Exe _ time TIMEDATE OUTPUT 722 PRESET OUTPUT 722 0HM 1E4 NPLC 0 DELAY 0 FOR I 1 TO 15 ENTER 722 A 1 NE OUTPUT 722 0HM 1E5 F E N Oo E E Oo E Oo W H H H x Fa O ve H 16 TO 23 NTER 722 A 1 UTPUT 722 OHMF 1E3 APER 20E 6 DELAY 1 722 A 24 NTER 722 A 25 UTPUT 722 ACV 250 ACBAND 250 DELAY 1 NTER 722 A 26 UTPUT 722 ACV 10 ACBAND 25000 DELAY 01
107. 0 70 80 90 OUTPUT Dvm 1 PRESET NORM NPLC 10 OFORMAT DREAL NRDGS 10 TRIG SYN 10 PLCs DCV AUTORANGE TRANSFER Dvm TO Rdgs WAIT FOR I 1 TO 10 IF ABS Rdgs I 1 E 38 THEN PRINT OVERLOAD OCCURRED 100E1SE 110Rdgs I DROUND Rdgs I 8 120PRINT Rdgs I 130END IF 140NEXT I 150END TRIG SYN SREAL OUTPUT FORMAT 1 PLC DCV AUTORANGE 10 READINGS SYN EVENT TRANSFER READINGS ENTER ONE 8 BIT BYTE INTO CONVERT READING FROM SREAL CONVERT READING FROM SREAL CONVERT READING FROM SREAL CONVERT READING FROM SREAL CONVERT READING FROM SREAL CONVERT READING FROM SREAL ROUND READING TO 7 DIGITS YOU IF OVERLOAD OCCURRED PRINT OVERLOAD MESSAGE IF NO OVERLOAD OCCURRED PRINT READING The following program uses the DREAL output format Notice that no conversion is necessary using this format since DREAL is the same format that the controller uses as its internal data format 8 bytes word COMPUTER ARRAY NUMBERING STARTS AT 1 CREATE BUFFER ARRAY ASSIGN MULTIMETER ADDRESS ASSIGN BUFFER I O PATH NAME DREAL OUTPUT FORMAT 10 RDGS TRIG SYN EVENT TRANSFER READINGS IF OVERLOAD OCCURRED PRINT OVERLOAD MESSAGE IF NO OVERLOAD ROUND READINGS PRINT READINGS The preceding program used the TRANSFER statement to get readings from the multimeter The following program uses the ENTER statement to transfer Chapter 4 Making Measurements 101 10 OPTION BASE 1
108. 0 Hz power line is 1 50 20 msec If you specify 10 PLCs the integration time is 200 msec In the power on state integration time is set to 10 PLCs In the PRESET NORM state integration time is set to 1 PLC To set the integration time for the fastest measurements with the lowest accuracy and 4 2 digits of resolution send OUTPUT 722 NPLC 0 To specify the most accuracy and Highest resolution 6 digits with the slowest measurement speed send OUTPUT 722 NPLC 1000 You can specify power line cycles in the following ranges e 0 1 PLC in 000006 PLC steps for 60Hz ref frequency or 000005 PLC steps for 50Hz ref frequency e 1 10 PLC in 1 PLC steps e 10 1000 PLCs in 10 PLC steps For integration times greater than 10 PLCs the multimeter averages a number of readings made using 10 PLCs of integration time For example Chapter 3 Configuring for Measurements 67 if you specify 60 PLCs of integration time the multimeter averages six 10 PLC readings Typically you should select the integration time that provides adequate speed while maintaining an acceptable amount of accuracy and resolution Table 18 shows the relationships between integration time and digits of resolution for analog AC measurements Table 18 Analog AC A D Converter Relationships Digits of Power Line Cycles NPLC command _ Resolution LFREQ 60OHz LFREQ 50Hz 4 5 0 000030 0 000025 5 5 000036 000360
109. 0 L L Inc 390 NEXT J n 450END 500RAD 510MOVE 520LDIR 400NEXT I i 410DISP CLEAR CONTROLLER CRT 420Time_div 1 0E 5 TIME PER DIVISION FOR PLOT 430Volts_div 5 VOLTS PER DIVISION FOR PLOT 440Plot_it Time_div Volts_div Wave_form Eff_int 460SUB Plot_it Time_div Volts_div Wave_form Time_base 470DIM X axis 80 Y_axis 80 480GINIT 490GRAPHICS ON 35 10 0 530X_axis TIME DIV amp VALS Time_div 540LABEL X_axis 550MOVE 560LDIR 15 35 PI 2 570Y_axis VOLTS DIV amp VAL Volts div 580LABEL Y_axis 590 VIEWPORT 20 110 20 90 600WINDOW 0 10 Time div 4 Volts div 4 Volts_ div 610AXES 620GRID 630Wave 640MOVE Time div 5 Volts_div 5 0 0 1 1 1 Time_div Volts_ div x 0 Wave _x Wave_form BASE Wav_form 1 650FOR Wave_y BASE Wave _form 1 1l TO SIZE Wave_form 1 1 BASE Wave_form 1 660 Wave _x Wave_x Time base Chapter 5 Digitizing 147 670 DRAW Wave _x Wave_form Wave_y 680NEXT Wave_y 690IF Wave_x gt 1l0 Time div THEN DISP More samples taken than displayed 700SUBEND 148 Chapter 5 Digitizing Chapter 6 Command Reference INO UCHON ecisesedeiscesdeieaev naa 151 TE REQ Sirie eaea tomsater 191 Language Conventions eseeeeseeeeeeeeeeees 152 LINE eligi endeared cit chee esas 192 Command Termination ccccecseeeserteeeees 152 LOCK cee susia send citeed conve a E EE in 193 Multiple Commands ccccsceeseeesteesteeeeeees 152 MATH p
110. 0 OUTPUT 722 ENDIF 100 OUTPUT 722 SUBEND 110 1 120 OUTPUT 722 CALL DMM CONE 130 END 280 Chapter 7 BASIC Language for the 3458A Appendix A Specifications Tntroduction cecceceesceeseeeseeeteesteceeceeeeeeeeeneessees 283 DC V oltage asain vette 284 Resistance per cies deh deh ied hokage 285 DC Current isene Ae GR ek 287 ACV Olta ge oes dts ceeds ceieesteetadetreutesecdeset dal EaR TE tes 288 AC Current ereer E E E E E 293 Frequency Period cccccecsccescceseeeeeeseeseenseeeees 294 Digitizing Specifications 0 0 eeeeseeeeeseeeeeeeeeees 295 System Specifications cccccsesseescesseesteeteeenees 297 Rati sireno n E aii 298 Math Functions cccccecceesseesseeeeeceteceeeeeeeeeeeensees 298 General Specifications cccccesseesseeteeeseeeteeeees 299 Appendix A Specifications 281 282 Appendix A Specifications Appendix A Specifications Introduction The 3458A accuracy is specified as a part per million ppm of the reading plus a ppm of range for dcV Ohms and dcl In acV and acl the specification is percent of reading plus percent of range Range means the name of the scale e g 1 V 10 V etc range does not mean the full scale reading e g 1 2 V 12 V etc These accuracies are valid for a specific time from the last calibration Absolute versus Relative Accuracy All 3458A accuracy specifications are relative to the calibration standards Absolute accuracy
111. 0 VDC the value returned is 0 If a reading is for example 10 1 VDC the value returned is Result 10 1 10 10 e100 0 01 e 100 1 OPTION BASE 1 DIM Perc 20 OUTPUT 722 PRESET NORM OUTPUT 722 NRDGS 20 OUTPUT 722 MATH PERC OUTPUT 722 SMATH PERC 10 ENTER 722 Perc PRINT Perc END COMPUTER ARRAY NUMBERING STARTS AT 1 DIMENSION ARRAY FOR 20 PRECENTAGES PRESET NRDGS 1 AUTO DCV 10 TRIG SYN 20 READINGS PER TRIGGER ENAB LE REAL TIME PERC OPERATION WRITE 10 TO PERC REGISTER SYN EVENT ENTER PERCENT DIFFERENCE PRINT PERCENT DIFFERENCE The following program is similar to the preceding program except that it uses the post process PERC operation OPTION BASE 1 DIM Perc 20 OUT OUT OUT OUT OUT OUT PUT PUT PUT PUT PUT PUT 722 PRESET NORM 722 MEM FIFO 722 NRDGS 20 COMPUTER ARRAY NUMBERING STARTS AT 1 nD SP IE t2 IMENSIO RESET N NABLE R 0 READI N ARRAY FOR 20 PERCENTAGES RDGS 1 AUTO DCV 10 TRIG SYN EADING MEMORY FIFO MODE NGS PER TRIGGER 722 MMATH PERC ENABLE POST PROCESS PERC OPERATION 722 SMATH PERC 10 WRITE 10 TO PERC REGISTER TRIGGER READINGS 722 TRIG SGL ENTER 722 Perc PRI END DB T Perc RECALL READINGS USING IMPLIED READ PERFORM rP RINT PE PERC OPERATION RCENT DIFFERENCE The DB math operation calculates a ratio in decibels The equation is Result 200l0g 0 Reading
112. 0 uV 30 kHz 200 us 1000V 10 MQ lt 500 uV 30 kHz 200 us DC Performance 0 005 of Reading Offset Maximum Sample Rate See DCV for more data Sample Timebase Accuracy 0 01 Readings sec Resolution Aperture Jitter lt 100 ps rms ne E Bis Cens External Trigger l 100 k 16 bits 1 4 us Latency lt 175 ns 2 50k 18 bit 6 0 Zs E Jitter lt 50 ns rms Level Trigger Latency lt 700 ns Jitter lt 50 ns rms 1 C of an AZERO or within 24 hours and 1 C of last ACAL lt 125 ns variability between multiple 3458As Appendix A Specifications 295 Dynamic Performance 100 mV 1 V 10 V Ranges Aperture 6 us Test DFT harmonics DFT spurious Differential non linearity Input 2 x full scale pk pk Result Signal to Noise Ratio 1 kHz lt 96 dB 1 kHz lt 100 dB dc lt 0 003 of Range 1 kHz gt 96 dB Direct and Sub sampled Digitizing DSDC DSAC SSDC and SSAC Functions Input Offset Typical Range 1 Impedance Voltage 2 Bandwidth 10 mV 1 MQ with 140 pF lt 50 uV 2 MHz 100 mV 1 MQ with 140 pF lt 90 uV 12 MHz 1V 1 MQ with 140 pF lt 800 uV 12 MHz 10 V 1 MQ with 140 pF lt 8 mV 12 MHz 100 V 1 MQ with 140 pF lt 80 mV 12 MHz 3 1000 V 1 MQ with 140 pF lt 800 mV 2 MHz DC to 20 kHz Performance 0 02 of Reading Offset Maximum Sample Rate Function Readings sec Resolution SSDC SSAC 100 M effective 4 16 bits DSDC DSAC 50k 16 bits Dynamic Performance 100 mV 1 V 10 V Ranges
113. 00 300 BASIC language are ENTER or TRANSFER The output statement is OUTPUT Read your computer manuals to find out which statements you need to use The examples in this manual use Hewlett Packard Series 200 300 BASIC language Before you can operate the multimeter from remote you need to know its GPIB address factory setting 22 To check the address press Address ma Changing the GPIB Address Sending a Remote Command Getting Data from the Multimeter A typical display is The displayed response is the device address When sending a remote command you append this address to the GPIB interface s select code normally 7 For example if the select code is 7 and the device address is 22 the combination is 722 Every device on the GPIB bus must have a unique address If you need to change the multimeter s address access the ADDRESS command from the command menu MENU keys with the display showing You can enter the new address For example press ag H Ce Enter You have now changed the address to 15 If you want to change the address back to 22 repeat the above procedure or use the Recall key and specify 22 instead of 15 To send the multimeter a remote command combine the computer s output statement with the GPIB select code the device address and finally the multimeter command For example to make the multimeter beep send O
114. 0kQ thermistor 40653C Function must be OHM or OHMF Result temperature Fahrenheit of a 2kQ thermistor 40653A Function must be OHM or OHMF Result temperature Fahrenheit of a 10kQ thermistor 40653C Function must be OHM or OHMF 194 Chapter 6 Command Reference Remarks MATH operation Numeric Parameter Equiv Description CRTD85 20 Result temperature Celsius of 100Q RTD with alpha of 0 00385 40654A or 406548 Function must be OHM or OHMF CRTD92 21 Result temperature Celsius of 100Q RTD with alpha of 0 003916 Function must be OHM or OHMF FRTD85 22 Result temperature Fahrenheit of 100Q RTD with alpha of 0 00385 40654A or 406548 Function must be OHM or OHMF FRTD92 23 Result temperature Fahrenheit of 100Q RTD with alpha of 0 003916 Function must be OHM or OHMF Power on operation_a operation_b OFF OFF Default operation_a operation_b OFF OFF Power on register values all registers are set to 0 with the following exceptions DEGREE REF 1 20 SCALE 1 RES 50 PERC 1 The FILTER RMS STAT or PFAIL math operations are performed on all subsequent readings However whenever the multimeter s configuration is changed the previous math results are erased and the operation starts over on the new readings All other math operations stay enabled until you set MATH OFF execute the MATH command specifying other math operation s or enable post process math operation s excep
115. 1034 B blingen Germany Revision B 01 Issue Date March 2001 Preface This manual contains installation information operating and programming information and configuration information for the 3458A Multimeter The manual consists of the following chapters Chapter 1 Installation and Maintenance This chapter contains information on initial inspection installation and maintenance It also contains lists of the multimeter s available options and accessories Chapter 2 Getting Started This chapter covers the fundamentals of multimeter operation It shows you how to use the multimeter s front panel how to send commands to the multimeter from remote and how to retrieve data from remote Chapter 3 Configuring for Measurements This chapter shows how to configure the multimeter for all types of measurements except digitizing digitizing is covered in Chapter 5 This chapter also shows you how to use subprogram and state memory the input buffer and the status register Chapter 4 Making Measurements This chapter discusses the methods for triggering measurements discusses the reading formats shows how to use reading memory and how to transfer readings across the GPIB bus This chapter also discusses how to increase the reading rate how to use the multimeter s EXTOUT signal and how to use the math operations Chapter 5 Digitizing Digitizing is the process of converting a continuous analog signal into a series of discrete s
116. 120V gt 120 to 1E3 1000V 1050V For all functions except the digitizing functions DSAC DSDC SSAC and SSDC the resolution parameter specifies the measurement resolution The multimeter ignores _ resolution when included with a digitizing command For Chapter 6 Command Reference Note Remarks Examples RANGE frequency and period measurements you specify resolution as the number of digits to be resolved For the remaining measurement functions DCV ACV ACDCV OHM OHMF DCI and ACI you specify the resolution as a percentage of the max _input parameter The multimeter then multiplies _resolution by the max input to determine the measurement s resolution For example suppose your maximum expected input is 10V and you want 1mV of resolution To determine resolution use the equation _resolution actual resolution maximum input x 100 In this example the equation evaluates to _resolution 001 10 x 100 0001 x 100 01 When using autorange the multimeter multiplies the _resolution parameter times the full scale reading of the selected range The result is the minimum resolution The multimeter always gives you at least the minimum resolution and in many cases gives you additional digits of resolution Power on resolution none At power on the resolution is determined by the NPLC command which produces 8 4 digits The power on value for NDIG masks display digit causing the mult
117. 13 14 Chapter 1 Installation and Maintenance Chapter 1 Installation and Maintenance Introduction Initial Inspection WARNING This chapter contains information on initial inspection installation and maintenance It also contains lists of the multimeter s available options and accessories It s a good idea to read this chapter before making any electrical connections to the multimeter If any of the following symptoms exist or are expected remove the multimeter from service 1 Visible damage 2 Severe transport stress 3 Prolonged storage under adverse conditions 4 Failure to perform intended measurements or functions Do not use multimeter until safe operation can be verified by service trained personnel The multimeter was carefully inspected before it left the factory It should be undamaged and in proper working order upon receipt If the shipping container or cushioning material is damaged keep it until the contents of the shipment have been checked and the multimeter has been inspected When you unpack the multimeter verify that the following items in addition to this user s guide are included Quick Reference Guide Qty 1 Calibration Manual Qty 1 e Line Power Cord Qty 1 Replacement line power fuses 5 00mA T Qty 1 for 220 240 operation 1 5A NTD Qty 1 for 100 120 operation Keyboard Overlay Qty 2 e Switch Lockout Caps Qty 2 If the multimeter is damage
118. 2 DCV 6 00167 DC VOLTS 6V MAX 1OOpV RESOLUTION 30 END In the following program line 10 sets the number of PLCs to 1000 This corresponds to maximum resolution and prevents resolution in line 20 from affecting the measurement The requested resolution from line 20 is 10mQ However because of line 10 the actual resolution is 1004 Q 10 OUTPUT 722 NPLC 1000 SETS PLCS TO MAXIMUM 20 OUTPUT 722 OHM 1E3 001 SELECTS 2 WIRE OHMS 1kQ MAX INPUT 30 END Number of Readings Designates the number of readings taken per trigger and the event sample event that initiates each reading NRDGS count event count 206 Chapter 6 Command Reference NRDGS Designates the number of readings per trigger event The valid range for this parameter is 1 to 16777215 The count parameter also corresponds to the record parameter in the RMEM command Refer to the RMEM command for details Power on count 1 Default count 1 event Designates the event that initiates each reading sample event The event parameter choices are Numeric event Query Parameter Equiv Description AUTO 1 Initiates reading whenever the multimeter is not busy EXTSYN 2 Initiates reading on negative edge transition on the multimeter s external trigger input connector SYN 5 Initiates reading when the multimeter s output buffer is empty reading memory is off or empty and the controller requests data TIMER 6 Similar to AUTO with a time interval b
119. 2 Executing a subprogram 72 INDEX 365 Execution suspending subprogram 72 Exponential parameters 35 External trigger buffering 88 triggering 87 EXTOUT 178 EXTOUT ONCE 115 EXTOUT signal 110 F f0 f9 keys 40 Factory address setting 20 Fast ACDCI example 107 ACI example 107 analog ACDCV example 106 analog ACV example 106 FREQ example 107 PER example 107 random ACDCV example 106 random ACV example 106 readings configuring for 103 synchronous ACV example 106 Ffast synchronous ACDCV example 106 FILTER 124 Filtering level 134 Fixed input resistance 62 FIXEDZ 180 Format using DINT output 99 using SINT output 99 using the DREAL output 101 using the SREAL output 101 Formats memory 95 output 98 reading 92 FREQ 181 example fast 107 FREQ key 29 Frequency 65 reference 58 Front panel 27 FSOURCE 182 FUNC 183 FUNCTION keys 29 Function changing the measurement 28 Function specifying a measurement 53 Fundamentals sub sampling 140 Fuse caps line 21 installing the line power 18 replacing a current 21 replacing the line power 21 G General configuration 47 GPIB high speed transfer across 107 GPIB address changing the 43 reading the 42 GPIB devices maximum number of 20 Grounding requirements 17 Guarding 51 H High speed DCI example 106 DCV example 105 mode 102 OHM example 105 OHMF example 105 transfer across GPIB 107 transfer from memor
120. 2 LFILTER ON ENABLES THE LEVEL FILTER The LFREQ command allows you to specify the A D converter s reference frequency or measure the line frequency and set the reference frequency to the measured value LFREQ frequency or LFREQ LINE frequency Allows you to specify the reference frequency The valid range for the frequency parameter is 45 65 Hz or 360 440 Hz When you specify a frequency in the range of 360 440Hz the multimeter divides that value by 8 For example if you specify LFREQ 400 the multimeter sets the reference frequency to 400 8 50Hz Power on reference frequency rounded value of 50 or 60Hz see first Remark below Chapter 6 Command Reference 191 LINE LINE Remarks Example Syntax Remarks Default reference frequency the exact measured line frequency or measured value 8 for 400Hz line frequency LINE Measures the exact value of the line frequency and sets the reference frequency to that value or measured value 8 if the measured value is between 360 and 440Hz e When power is applied the multimeter measures the line frequency rounds it to 50 or 60Hz and sets the A D Converter s reference frequency to the rounded value For a 400Hz power line frequency the multimeter uses 50Hz as a reference frequency which is a subharmonic of 400Hz The step size for the period of the reference frequency is 100ns For example the period of a 60Hz reference frequency is 1 60Hz 016666
121. 2 0 4 0 04 0 55 0 15 1A 0 4 0 02 0 16 0 02 0 08 0 02 0 1 0 02 0 3 0 02 1 0 04 AC DC Accuracy ACDCI Function For ACDCI Accuracy apply the following additional error to the ACI accuracy of Reading of Range DCs10 of AC DC gt 10 of AC Accuracy Temperature Coefficient 5 Accuracy Temperature Coefficient 5 0 005 0 02 0 0 001 0 15 0 25 0 0 0 007 Additional Errors Apply the following additional errors as appropriate to your particular measurement setup LOW Frequency Error of Reading ACBAND Low Signal 10 Hz 1 kHz 1to10 kHz gt 10 kHz Crest Factor Error of Reading Frequency NPLC gt 10 NPLC gt 1 NPLC gt 0 1 0200Hz 0 Crest Factor Additional Error 200 500 Hz 0 0 15 1 2 0 500 1kHz 0 0 015 0 9 2 3 0 15 1 2 kHz 0 0 0 2 3 4 0 25 2 5 kHz 0 0 0 05 4 5 0 40 5 10 kHz 0 0 0 01 Reading Rates 6 Maximum Sec Reading ACBAND Low NPLC ACI ACDCI 210 Hz 10 1 2 1 21 kHz 1 1 0 1 210 kHz 0 1 1 0 02 Additional error beyond 1 C but within 5 C of last ACAL Specifications apply full scale to 1 20 full scale for sine wave inputs crest factor 1 4 and following PRESET within 24 hours and 1 C of last ACAL Add 5 ppm of reading additonal error for Keysight factory traceabiltiy to US NIST Traceability is the sum of the 10V and 10 kQ traceability values Typical performance 1 kHz maximum on the 100 pA range Additional error beyond 1 C but within 5 C of l
122. 2 The TIMER or LINE event cannot be used for AC or AC DC voltage measurements using the synchronous or random method or for frequency or period measurements Making Continuous Readings In the power on state the multimeter s trigger arm trigger and sample events are all set to AUTO This causes the multimeter to take readings continuously Typically continuous readings should be suspended before configuring the multimeter using either the TARM HOLD or TRIG HOLD command or by setting the multimeter to one of the PRESET states see Suspending Readings in Chapter 3 After configuring the multimeter you can resume continuous readings assuming the other triggering events have not been changed by sending Chapter 4 Making Measurements Making Single OUTPUT 722 TARM AUTO Resumes readings suspended by TARM HOLD PRESET FAST or PRESET DIG or OUTPUT 722 TRIG AUTO Resumes readings suspended by TRIG HOLD or PRESET NORM The NRDGS command specifies the number of readings made per trigger event and the sample event that initiates each reading In the power on Readings RESET PRESET NORM or PRESET FAST state the number of readings per trigger is set to 1 and the sample event is AUTO NRDGS 1 AUTO In any of these states you can initiate a single reading by executing the TARM SGL or TRIG SGL command depending on which event if any is suspending readings For example the following program resets the multimeter and susp
123. 2 to 120 100mV 120mV 500mV gt 120 to 1 2 1V 1 2V 5 0V gt 1 2 to 12 10V 12V 50V gt 12 to 120 100V 120V 500V gt 120 to 1E3 1000V 1050V 1050V For SSAC or SSDC max _input Selects Full Parameter Range Scale 0 to 012 10mV 12mV gt 012 to 120 100mV 120mV gt 120 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to 1E3 1000V 1050V _resolution Note Remarks FUNC For most measurement functions you specify the resolution as a percentage of the max _ input parameter Refer to the FREQ and PER commands for tables showing how _ resolution affects frequency and period measurements _resolution is ignored when the function parameter is DS AC DSDC SSAC or SSDC For all functions except FREQ PER DSAC DSDC SSAC and SSDC the multimeter multiplies resolution times max input to determine the measurement s resolution For example suppose you are measuring DC voltage your maximum expected input is 10V and you want ImV of resolution To determine resolution use the equation _resolution actual resolution maximum input x 100 For this example the equation evaluates to _resolution 001 10 x 100 0001 x 100 01 When using autorange the multimeter multiplies the _ resolution parameter times the full scale reading of the selected range The result is the minimum resolution The multimeter always gives you at least the minimum resolution and in many cases gives you additional
124. 235 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 OUTPUT Dvm ISCALE ENTER Dvm S OUTPUT Dvm SSPARM ENTER Dvm N1 N2 N3 FOR I 1 TO Num_samples Samp I Int_samp I SSRC QUERY SCALE FACTOR FOR SINT FORMAT ENTER SCALE FACTOR QUERY SUB SAMPLING PARAMETERS ENTER SUB SAMPLING PARAMETERS CONVERT EACH INTEGER READING TO REAL FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE R ABS Samp I USE ABSOLUTE VALUE TO CHECK FOR OVLD IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE Samp I Samp I S Samp I DROUND Samp I 4 NEXT I Inc N1 N2 1 FOR I 1 TO N1 L 1 FOR J 1 TO N3 K 1 L L Inc NEXT J NEXT I FOR I N1 1 TO N1 N2 L I FOR J 1 TO N3 1 Kt 1 L L Inc NEXT J NEXT I 420 END Wave_form L Samp K Wave_form L Samp K MULTIPLY READING TIMES SCALE FACTOR ROUND TO 4 DIGITS TOTAL NUMBER OF BURSTS In the following program the SSRC EXT event is used with synchronous AC voltage measurements After the trigger event occurs the trigger arm and sample events are AUTO the first low going TTL transition on the Ext Trig connector initiates the first burst Each successive external trigger will then initiate a burst until the necessary number of bursts are completed 10 20 30 40 50 60 70 O O O O E P E UTPUT 722 PRESET NORM UTPUT
125. 255 Trig key 33 Trigger arming multiple 84 buffering external 88 event 82 Trigger arm event 82 Triggering examples level 132 external 87 level 132 measurements 81 setup 105 Two s complement binary coding 92 U USER keys 40 User defined keys 40 Using configuration keys 32 DINT output format 99 DREAL output format 101 implied read 97 Input buffer 75 MENU keys 36 reading memory 94 reading numbers 96 SINT output format 99 SREAL output format 101 state memory 74 status register 75 subprogram memory 71 V Values default 34 Verification installation 21 Viewing Long Displays 38 Voltage AC 62 AC DC 62 limits line 18 method specifying the AC 64 switches setting the line 18 W WARNINGS 3 Warranty repairs 22 warranty statement 2 Waveform aperture 114 372 INDEX This information is subject to change without notice Keysight Technologies 1988 2014 Edition 7 August 2014 KEYSIGHT ANT TECHNOLOGIES 03458 90014 www keysight com
126. 550 2560 2570 2580 2590 2600 2610 2620 2630 2640 2650 2660 2670 2680 2690 2700 2710 2720 2730 2740 2750 2760 2770 2780 2790 2800 2810 2820 2830 2840 2850 2860 2870 2880 2890 2900 10 20 30 40 50 60 OUTPUT 722 ACV 10 ACBAND 25000 DELAY 01 TRIG SGL OUTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 6 TRIG SGL OUTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY 01 NRDGS 1 TRIG SGL OUTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 3 TRIG SGL SUBEND Dnld_time TIMEDATE Dnld_time Exe time TIMEDATE OUTPUT 722 CALL 1 Exe_time TIMEDATE Exe_time Tns_time TIMEDATE FOR I 1 TO 37 NTER 722 A 1 E N Tns_time TIMEDATE Tns_time SUBEND SUB Azero REAL Dnid_time Exe_time Tns_time DIM A 37 Dnid_time TIMEDATE OUTPUT 722 PRESET MFORMAT SREAL DISP OFF TESTING AZERO OFF OUTPUT 722 SUB 1 MEM FIFO OHM 1E4 NPLC 0 DELAY 0 NRDGS 15 TRIG SGL OUTPUT 722 OHM 1E5 NRDGS 8 TRIG SGL OUTPUT 722 OHMF 1E3 APER 20E 6 DELAY 1 NRDGS 2 TRIG SGL OUTPUT 722 ACV 250 ACBAND 250 DELAY 1 NRDGS 1 TRIG SGL OUTPUT 722 ACV 10 ACBAND 25000 DELAY 01 TRIG SGL OUTPUT 722 DCV10 NPLC 0 DELAY 0 NRDGS 6 TRIG SGL OUTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY 01 NRDGS 1 TR1G SGL OUTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 3 TRIG SGL SUBEND Dnld_time TIMEDATE Dnld_time Exe time TIMEDATE OUTPUT 722 CALL 1 Exe_time TIMEDATE Exe_time Tns_tlme TIMEDATE FOR I 1 TO 37 ENTER 722 A I NEXT Tns_time TIMEDATE Tns_time S
127. 6 Since the step size is 100ns the multimeter uses the value of 0166667s The step size is most noticeable when using the LFREQ query command For example if you have specified 60Hz as the reference frequency the LFREQ returns 59 99988 1 0166667 The multimeter multiplies the period of the reference frequency times the specified number of power line cycles NPLC command to determine the actual integration time The multimeter s normal mode noise rejection NMR specifications for DC and resistance measurements are related to the accuracy of the A D converter s reference frequency Query Command The LFREQ query command returns the present value of the line frequency reference used by the multimeter s A D converter Since the step size is 100ns if the period of the value specified is not evenly divisible by 1 100ns the value returned by LFREQ will be slightly different than the value specified Refer to Query Commands near the front of this chapter for more information e Related Commands LINE NPLC OUTPUT 722 LFREQ LINE MEASURES LINE FREQUENCY SETS REFERENCE FREQUENCY TO MEASURED VALUE OR MEASURED VALUE 8 FOR 400HZ LINE FREQUENCY Line Frequency Query Measures and returns the frequency of the AC power line LINE Refer to the LFREQ command on the previous page for an example showing how to measure the line frequency and automatically set the A D converter s 192 Chapter 6 Command Reference LOCK MAT
128. 60 270 280 290 300 310 320 330 340 350 360 370 380 390 400 410 420 430 PRINT EXECUTION TIME Exe time PRINT TRANSFER TIME Tns_ time PRINT TOTAL TIME Dnid_time Exe time Tns_ time END Bench Mark Test COM Dnld_trme Exe_time Tns_time l CALL Default Dnld _ time Exe_time Tns_time PRINT USING 36A DD DDD The execution time for default is Exe_time PRINT CALL Fixed Dnld_time Exe_time Tns_ time PRINT USING 38A DD DDD The execution time for fixed range is Exe_time PRINT CALL Integrat Dnld_time Exe_time Tns_time PRINT USING 51A DD DDD The execution time for correct integration time is Exe time PRINT CALL Delay Dnld_time Exe_time Tns_ time PRINT USING 44A DD DDD The execution time for correct delay time is Exe_time PRINT CALL Burst Dnld_time Exe_time Tns_time PRINT USING 44A DD DDD The execution time for storing readings is Exe_time PRINT USING 44A DD DDD The transfer time using FOR NEXT is Tns_time PRINT USING 44A DD DDD The total time for memory IS Exe time Tns_ time PRINT CALL Program Dnld_time Exe_time Tns_time PRINT USING 44A DD DDD The execution time for program memory is Exe_time PRINT USING 44A DD DDD The download time for transfering the SUB is Dnld_time PRINT USING 44A DD DDD The transfer time using FOR NEXT is Tns_ time PRINT USING 44A DD DDD The total time for program memory is Exe_time Dnld_timet T
129. 722 20 ENTER 722 A OUTPUT 7 DIV 3 30 PRINT DIV Result A 40 END Typical Printout DIV Result 2 The MOD command returns the remainder portion of a division As with the DIV command normal division takes place however MOD returns only the remainder The following program divides 7 by 3 and displays the remainder portion of the division 1 on the system controller LO OUTPUT 722 20 ENTER 722 A 30 PRINT MOD Result A 40 END OUTPUT 7 MOD 3 Typical Printout MOD Result 1 Relational math operators lt gt lt gt lt gt and logical operators AND and OR are allowed in any expression The following table lists the general math functions available in the 3458A The arguments denoted by X and Y may be numbers numeric variables functions array elements or numeric expressions in parentheses Function Argument ABS X SQR X Meaning Absolute value of argument Positive square root of argument The 3458A can compute both natural and common logarithms The logarithmic functions are shown in the following table Function Argument LOG X Meaning Log X Natural logarithm of a positive argument to the base e 2 71828 Chapter 7 BASIC Language for the 3458A Trigonometric Functions Logical Functions Binary Functions Function Argument Meaning EXP X e Natural antilogarithm Raises e to the power of the argument LGT X Log49 Common logarithm
130. 722 S 90 PRINT S 100 END COMPUTER ARRAY NUMBERING STARTS AT 1 DIMENSION ARRAY FOR 20 READINGS PRESET NRDGS 1 AUTO DCV 10 TRIG SYN 20 READINGS PER TRIGGER ENABLE REAL TIME STAT OPERATION SYN EVENT ENTER READINGS READ STANDARD DEVIATION ENTER STANDARD DEVIATION PRINT STANDARD DEVIATION The following program performs the post process STAT operation on 20 readings stored in memory The post process STAT operation is a batch Chapter 4 Making Measurements operation That is the readings do not have to be recalled from memory in order to perform the STAT operation Also notice that the readings must be stored before enabling the post process STAT operation if not the MEMORY ERROR will occur 10 OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 TRIG SYN 20 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 30 OUTPUT 722 NRDGS 20 20 READINGS PER TRIGGER 40 OUTPUT 722 TRIG SGL TRIGGER READINGS 50 OUTPUT 722 MMATH STAT PERFORM POST PROCESS STAT OPERATION 60 OUTPUT 722 RMATH SDEV READ STANDARD DEVIATION 70 ENTER 722 S ENTER STANDARD DEVIATION 80 PRINT S PRINT STANDARD DEVIATION 90 END Pass Fail The PFAIL math operation tests each reading against the limits set in the MAX and MIN registers If a boundary is exceeded the hi low bit of the status register is set Also the number of readings that passed the PFAIL operation before a fail
131. 8 Output Formats esensina 98 Output Termination 2 0 0 cccecsceseeceeeteeseesseens 99 Using the SINT or DINT Output Format 99 Using the SREAL Output Format 0 101 Using the DREAL Output Format 00 101 Increasing the Reading Rate eee eeeeeeeeeees 102 High Speed Mode eecceceeseeseeseeereeteeteenee 102 Configuring for Fast Readings eee 103 High Speed Transfer across GPIB 04 107 High Speed Transfer from Memory 108 Determining the Reading Rate 0 ee 109 The EXTOUT Signal 0 0 cece eceeeeceeeeeeeeeeeeeeeeens 110 Reading Complete ccccccccscsseceteeeteeeeeeees 112 Burst Complete eccecceeceeceeseeeeeeeeeeeeseeaeees 113 Input Complete ieecsiecises ied cthtievecsanctvenstenvisten 114 Aperture Waveform cecceceeceeseeseeereeeeeseens 114 Service REQUest nnc R 114 EXTOUT ONCE sgeenestitreccstsener aerate 115 Math Operations ceceeecesceeceeeeeeeeeceeeeseeaeeenees 116 Real Time vs Post Process 116 Enabling Math Operations eceseseeeeee 116 Math Registers cccccccsseesseeseeseceteeeteeseeeees 117 EDI D PES E A ees 117 SCALE osiers a a sE 119 PQQCO Mt ics lt caecdes Jeteasdec dena ticonet eenei 120 DB rnea ens idl ates 120 DBM siasabiesiagcausendutiaseadeatcn tediasphagerobiatansanctaiatal 121 Statistics caccscisscvesicagevestasocnssnie AEE 122 Pass Fail 13 cccecasvidsevstetsfertette
132. A for details 2 Effective sampling rate refer to Sub Sampling later in this chapter for details DCV SIGNAL CONDITIONING 15 KHz MAX BANDWIDTH DIRECT amp SUB SAMPLING SIGNAL CONDITIONING 12MHz BANDWIDTH 34560PC F 5 24 TRACK AND HOLD Figure 23 Digitizing signal paths yi Maru JEJ Error Clear ALT Term 180v bee i AN 34ea0rPC F 2 2 A D CONVERTER TO MEMORY OR OUTPUT BUFFER ES gi INPUT SIGNAL FOR GUARDED MEASUREMENTS ONLY Figure 24 Digitizing measurement connections For most digitizing applications the multimeter enters its high speed mode whenever sampling is initiated In the high speed mode the multimeter becomes completely dedicated to taking samples This means that it will not process any commands until the specified number of samples are completed When samples are sent directly to the output buffer in the high speed mode the multimeter waits until each sample is removed from the output buffer before placing the next sample in the output buffer This ensures that samples will not be lost because of bus controller speed limitations When not in the Chapter 5 Digitizing high speed mode the multimeter writes over any sample still in the output buffer when a new sample is available For more information refer to The High Speed Mode in Chapter 4 The Sampling Rate The Nyquist or Sampling Theorem states If a continuous bandwidth limit
133. ATIO rere na a a saute dete dots 224 DEFEAT ennai a ARA 168 RES eae a ee E 225 DEEKEY eiere ra re E eqarerneeaeesetts 169 RESET kinle i 226 DELAY aa e O ies eee eee AES 170 REV attnr E aant RAS 228 DELSUB peh eara e 171 RMATH teninin aa n a ied 228 DIAGNOS Ta n a a a e Be 171 RMEM r tern r En aa a iae 229 DI AS 2 ras E E N 171 ROS era e aea in ee Sa A a oeat 230 DSAG DSDE anemoon RaR 172 RSTATE moea Tean E 231 EMAS K enaena aA 174 SCAD a i a a i 232 END marinn a a aa a a 176 SCRATCH sararae a a NERE 232 ERR noiri ee e e N N s 177 SECURE onar aaa a avait 232 ERRS TR vatevsstersdanesideusschdeanidemspacdsiacssiaacatis 178 SETAC V uere aee E EA n 233 EXTOUT peent er nE AE 178 SCOPE rr E tenn tien AE 234 FIXED h ee ae o dats neareies 180 SMA TH secs dices ectecusctiesateedoere devia rs deeeereseeee dots 235 EREQ iena oa e a a aa 181 SRO E E EES 236 FSOUR CE ei et e eetere rera EE 182 SSAC SSD Colorete eio iaa 237 EUNC een en A NRE 183 SSPARM minnanna AEA 240 ID ienne e a gad O 186 SOR Garn aa MEN ee ee 240 TINUE pina A ET OE 186 SSTA TE aara a a OEE 244 ISCAEE raro rea e eE eet aE TERS 187 SH B V A EE Arete teeiee 245 LEVEL aserne Tr a e aaa aaia 189 SUB ieena reee a e e 246 TBI DT ER eeen a a 190 SUBEND ae a a eden ai ee 248 Chapter 6 Command Reference 149 De E tisha csapar sdaitea sd cavveduastvebonetianadbes 251 TARM isis es seed ssuetis cncatigeae sels teh T dete 251 TBU PP 55 forse tees sass des aa ee E seni sonete leases 253 TEM
134. BIG SMALL 298 Expression to calc M OUTPUT Dvm OUTPUT M Send calc ed result to bus OUTPUT Dvm SUBEND End of DMM subprogram OUTPUT Dvm TARM SGL Trigger dmm acquisition TO TIMEDATE Store start time T1 TIMEDATE OUTPUT Dvm CALL CALC MEAN Tell DMM to execute sub Chapter 7 BASIC Language for the 3458A 265 Sample Results From Program Execution 500 ENTER Dvm Mean Read M into computer 510 T2 TIMEDATE Store end time 520 PRINT MEAN Mean TRANSFER AND CALCULATION SPEED T2 T1 T1 TO 530 PRINT 540 END MEAN 54 73391112 TRANSFER AND CALCULATION SPEED 399963378906 Variables and Arrays 266 Type Declarations The 3458A employs two forms of numeric variables simple variables also called scalars and subscripted arrays Variable usage in the 3458A is very similar to variable usage in an enhanced BASIC language The 3458A does not provide string variables All variables are global among front panel GPIB and subprogram operations This means that you can dynamically change variable values The 3458A uses two data types for its variables Integer or Real All variables are real unless you declare them as integer The valid range for real numbers is 1 797 693 134 862 315 X 1030 to 1 797 693 134 862 315 X 10308 The smallest non zero real value allowed is 42 225 073 858 507 202 X 10 38 A real number can have a value of zero An integer can have any whole number value from
135. CS OF INTEGRATION TIME 20 OUTPUT 722 DCV 7 DC VOLTAGE 10V RANGE 30 OUTPUT 722 MATH OFF SHUTS OFF MATH FUNCTIONS 40 OUTPUT 722 MEM FIFO ENABLES READING MEMORY FIFO MODE 50 OUTPUT 722 MFORMAT DINT SELECTS DINT MEMORY FORMAT 60 END When recalling the stored data make sure that the multimeter is configured as it was when you stored the data Memory Math Enables or disables post process math operations MMATH operation_a operation_b operation The operation parameter choices are operation Numeric Parameter Equiv Description OFF 0 Disables all post process math operations CONT 1 Enables the previous math operation To resume two math operations send MMATH CONT CONT CTHRM 3 Result temperature Celsius of a 5KQ thermistor 40653B Function must be OHM or OHMF 10kQ range or higher DB 4 Result 20 x log reading REF register The REF register is initialized to 1 yielding dBV DBM 5 Result 10 x log reading RES register I1mW Function must be ACV DCV or ACDCV FILTER 6 Result output of exponentially weighted digital low pass filter Response is set by DEGREE register 200 Chapter 6 Command Reference operation Parameter FTHRM NULL PERC PFAIL RMS SCALE STAT CTHRM2K CTHRM10K FTHRM2K FTHRM10K CRTD85 CRTD92 FRTD85 FRTD92 Numeric Equiv 8 MMATH Description Result temperature Fahrenheit of a 5kQ thermistor 40653B F
136. CV 10 20 OUTPUT 722 SETACV SYNC 30 OUTPUT 722 RATIO ON 40 END Later to disable ratio measurements send OUTPUT 722 RATIO OFF For ratio measurements the specified measurement range applies to the signal voltage measurement only Input terminals The reference voltage measurement Q Sense terminals is always set to autorange Ranging is discussed in detail earlier in this chapter under General Configuration Using Subprogram Memory Note Storing a Subprogram The multimeter can store command strings as subprograms This allows you to execute frequently used command strings while keeping bus controller interaction to a minimum Since stored subprograms are compiled the multimeter executes a subprogram much faster than it could execute the equivalent commands sent over the GPIB The multimeter has 14k bytes of memory that are shared by subprograms and states discussed later When subprogram state memory becomes full the multimeter generates the Memory Error bit 7 in the error register The status register contains a subprogram complete bit that can be used to determine when a subprogram has finished executing Refer to Using the Status Register later in this chapter for more information You store a subprogram using the SUB and SUBEND commands The SUB command indicates the start of the subprogram and its identifying name A subprogram name may contain up to 10 characters The name can be all alpha char
137. Computers using BASIC language They assume an GPIB interface select code of 7 and a device address of 22 factory address setting resulting in a combined GPIB address of 722 We recommend you retain this address to simplify programming The carriage return cr line feed Zf semicolon or EOI sent concurrent with the last character indicate the end of message command terminator to the multimeter When you send a command from the system controller in the standard format e g OUTPUT 722 TEST the controller typically adds a cr If to the end of the command With its input buffer off off is the power on input buffer mode the multimeter processes the cr immediately but does not process the f until the command completes execution This means that because of the f the bus is held and you cannot regain use of the controller until the multimeter is done executing the command or the GPIB CLEAR command is executed which aborts execution of the command You can prevent the bus from being held by suppressing the cr f when sending commands or by enabling the input buffer INBUF ON command The following program line shows how to use the and K image specifiers to suppress cr If when sending a multimeter command OUTPUT 722 USING K TEST The and K image specifiers apply to HP Series 200 300 computers Refer to your computer s operating manual for information on how your computer suppresses cr If The semicolon following the
138. Coupled measurement technique In these modes the input is sampled through a track hold with a fixed 2 ns aperture which yields a 16 bit resolution result The sample rate is selectable from 6000 sec sample to 20 us sample with 100 ns resolution Input voltage ranges cover 10 mV peak to 1000 V peak full scale The input bandwidth is limited to 12 MHz SSDC Sub Sampling Effective time sampling DC Coupled SSAC Sub Sampling Effective time sampling AC Coupled These techniques implement synchronous sub sampling of a repetitive input signal through a track hold with a 2 ns sample aperture which yields a 16 bit resolution result The effective sample rate is settable from 6000 sec sample to 10 ns sample with 10 ns resolution Sampled data can be time ordered by the instrument and output to the GPIB Input voltage ranges cover 10 mV peak to 1000 V peak full scale The input bandwidth is limited to 12 MHz Summary of Digitizing Capabilities Technique Function Input Bandwidth Best Accuracy Sample Rate Standard DCV DC 150 kHz 0 00005 0 01 100 k sec Direct sampled DSDC DSAC DC 12 MHz 0 02 50 k sec Sub sampled SSDC SSAC DC 12 MHz 0 02 100 M sec effective Standard DC Volts Digitizing DCV Function Input Offset Typical Settling Time L Range Impedance Voltage 1 Bandwidth to 0 01 of Step 100mV gt 100Q lt 5uV 80 KHz 50 us 1V gt 10 O lt 5 uV 150 kHz 20 us 10V gt 10 o lt 5 uV 150 kHz 20 us 100 V 10 MQ lt 50
139. DCV ACV ACDCV Reference error 1 5 x Total error for the range of the reference DC input 10 Math Functions General Math Function Specifications Math is executable as either a real time or post processed operation Math function specifications do not include the error in X the instrument reading or errors in user entered values The range of values input or output is 1 0 x 1037 to 1 0 x 10 Out of range values indicate OVLD in the display and 1 x 10 to GPIB The minimum execution time is the time required to complete one math play operation after each reading has completed NULL X OFFSET Minimum Execution Time 180 us PERC 100 x X PERC PERC Minimum Execution Time 600 us dB 20 x Log X REF Minimum Execution Time 3 9 ms RMS 1 pole digital filter Computed rms of inputs Minimum Execution Time 2 7 ms STAT MEAN SDEV computed for sample population N 1 NSAMP UPPER LOWER accumulated Minimum Execution Time 900 us CTHRM2K FTHRM2k C F temperature conversion for 2 2 KQ thermistor Keysight 40653A Minimum Execution time 160 us CRTD85 FRTD85 C F temperature conversion for RTD of 100 Q Alpha 0 00385 Minimum Execution Time 160 us 298 Appendix A Specifications SCALE X OFFSET SCALE Minimum Execution Time 500 us PFAIL Based on MIN MAX registers Minimum Execution Time 160 us dBm 10 x Log X RES 1 mW Minimum Execut
140. Def Key 40 Default delays 87 values 34 364 INDEX Defaulting parameters 152 DEFEAT 168 DEFKEY 169 DELAY 170 Delay time 105 Delayed readings 86 Deleting states 75 subprograms 74 DELSUB 171 Determining the reading rate 109 Devices GPIB maximum number of 20 DIAGNOST 171 Digitizing DCV 134 methods 129 Digits displayed 39 DINT example 100 output format using 99 Directly specifying integration time 60 Direct sampling 137 example 139 remarks 138 DISP 171 Display 26 clearing the 37 control 37 editing 38 MORE INFO 39 test 32 window keys 38 Displayed digits 39 Displays viewing long 38 documentation history 3 Double integer 92 Double real 94 DREAL output format 101 DSAC 172 DSDC 172 E Editing display 38 EMASK 174 Enabling math operations 116 END 176 ENTER statement 42 ERR annunciator 27 ERR 177 Error register reading the 31 registers reading the 48 Error key 31 ERRSTR 178 Event choices 82 sample 82 sync source 141 trigger 82 trigger arm 82 Event combinations 88 Example DCV 136 DINT 100 direct sampling 139 fast ACDCI 107 fast ACI 107 fast analog ACDCV 106 fast analog ACV 106 fast FREQ 107 fast PER 107 fast random ACDCV 106 fast random ACV 106 fast synchronous ACDCV 106 high speed DCI 106 high speed DCV 105 high speed OHM example 105 high speed OHMF 105 SINT 99 SREAL 93 Examples level triggering 13
141. E3 SIGNAL BETWEEN 10kHz AND 20kHz 722 NRDGS 100 AUTO 1100 READINGS TRIGGER AUTO SAMPLE EVENT 722 TARM SGL TRIGGER READINGS Configuring the output format OFORMAT command to match the format used by the A D converter either SINT or DINT ensures the fastest transfer of readings to the controller This is because no format conversion is required in the multimeter For high speed low resolution readings 3 5 or 4 5 digits made on a fixed range use the SINT output format Because the SINT format uses only 2 bytes per reading multiple readings can be transferred across the bus faster using the SINT output format than any other format For the fastest transfer of high resolution readings 5 5 digits or greater made on a fixed range use the DINT output format The multimeter is capable of taking readings and outputting them to the controller at gt 100k readings per second Using the SINT output format at this reading rate the GPIB and controller must be able to transfer data at gt 200k bytes per second For Hewlett Packard Series 200 300 Computers this requires a direct memory access DMA card In addition devices that slow the operation of the GPIB bus and any unnecessary lengths of GPIB cable must be removed to achieve maximum transfer rate Chapter 4 Making Measurements 107 10 OPTION BASE 1 The following program transfers readings directly to the controller at the fastest possible rate This program configures the multim
142. ECK FOR OVLD 80 IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE 90 Samp I Samp I S MULTIPLY READING TIMES SCALE FACTOR 200 Samp I DROUND Samp IT 4 ROUND TO 4 DIGITS 210NEXT I 220END Direct Sampling Direct sampling is similar to DCV digitizing in that samples are taken in real time with each successive sample spaced a specified time interval from the preceding sample The difference between the two is that direct sampling uses the multimeter s track and hold circuit and has a wider bandwidth input path 12 MHz bandwidth In addition direct sampling has less trigger jitter but greater measurement noise than DCV digitizing see the Specifications in Appendix A The track and hold circuit takes a very fast sample of the input signal and then holds the value while the A D converter integrates it By using the track and hold circuit the width of each sample is reduced from a minimum of 500 nanoseconds for DCV to 2 nanoseconds for direct sampling This makes direct sampling ideal for applications such as capturing the peak amplitude of a narrow pulse The disadvantage of direct sampling is a slower maximum sampling rate of 50 000 samples per second versus 100 000 for DC voltage You specify direct sampling using the DSAC or DSDC command The DSAC command selects AC coupling which measures only the AC component of the input signal The DSDC command selects DC coupling which measures the combined AC and DC compon
143. EMOTE 722 RETURNS THE MULTIMETER TO REMOTE MODE LOCAL LOCKOUT LLO REMOTE Syntax Remarks Examples Syntax Remarks Disables the multimeter s LOCAL key LOCAL LOCKOUT 7 If the multimeter is in the local state when you send LOCAL LOCKOUT it remains in local Ifthe multimeter is in the remote state when you send LOCAL LOCKOUT its LOCAL key and keyboard are disabled immediately e After disabling the LOCAL key with LOCAL LOCKOUT you can only enable it by sending the GPIB LOCAL 7 command or by cycling power If the multimeter s LOCAL key is disabled by LOCAL LOCKOUT the LOCAL 722 command enables the keyboard but a subsequent remote command disables it Sending the LOCAL 7 command however enables the LOCAL key and keeps it enabled even after a subsequent remote message If the multimeter s keyboard is disabled by both LOCAL LOCKOUT and the LOCK command you must clear both to regain control of the keyboard LOCAL LOCKOUT is cleared with the LOCAL command LOCK is cleared by setting LOCK to OFF 10 REMOTE 722 SETS DEVICE AT ADDRESS 22 TO REMOTE STATE 20 LOCAL LOCKOUT 7 SENDS LOCAL LOCKOUT LLO TO ALL 30 END DEVICES ON THE BUS Sets the GPIB REN line true REMOTE 7 REMOTE 722 The REMOTE 722 command places the multimeter in the remote state The REMOTE 7 command does not by itself place the multimeter in the remote state After sending the REMOTE 7 command the multimeter will only go into the remote
144. ENABLE READING MEMORY 40 OUTPUT 722 SETACV RNDM RANDOM AC MEASUREMENT METHOD 50 OUTPUT 722 ACV 10 6 AC VOLTS 10V RANGE 6 RESOLUTION 60 OUTPUT 722 ACBAND 10E3 20E3 SIGNAL BETWEEN 10kHz AND 20kHz 70 OUTPUT 722 NRDGS 100 AUTO 1100 READINGS TRIGGER AUTO SAMPLE EVENT 80 OUTPUT 722 TARM SGL TRIGGER READINGS 90 END Fast Analog ACV ACDCV The following program measures AC voltage using the analog method at a Example fast rate This program uses the default delay time You can achieve faster reading rates by specifying a shorter delay time the resulting settling time however may not produce accurate measurements You can also achieve unspecified faster reading rates by specifying less integration time in line 60 This program can be adapted to AC DC voltage by using the ACDCV command instead of the ACV command in line 50 10 OUTPUT 722 PRESET FAST TARM SYN TRIG AUTO 20 OUTPUT 722 MFORMAT SINT SINT MEMORY FORMAT 30 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 40 OUTPUT 722 SETACV ANA ANALOG AC MEASUREMENT METHOD 106 Chapter 4 Making Measurements 50 60 70 80 90 OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT 100 END Fast ACI ACDCI Example 10 20 30 40 50 60 70 80 90 Fast FREQ or PER 10 20 30 40 50 60 70 80 High Speed Transfer across GPIB OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT END L223 ACY 10 AC VOLTS 10V RANGE 722 NPLC 0 1 0 1 PLC
145. ER NABLE POST PROCESS DBM OPERATION RIGGER READING RECALL READING USING IMPLIED READ PERFORM DBM OPERATION Lp RINT DBM RESULT The STAT math operation performs five calculations on a group of readings and stores the results in five math registers The calculations are standard deviation mean number of samples largest reading and smallest reading Table 24 shows the STAT registers and their contents You can read any of the STAT registers using the RMATH command Table 24 STAT Registers Stored Result Standard deviation Average of the readings Number of readings in this group of measurements Largest reading in this group of measurements Smallest reading in this group of measurements The following program uses the real time STAT operation to perform five running calculations on 20 DC voltage readings After the readings are taken and transferred to the controller the standard deviation is read and returned 70 PRINT A 80 END 10 OUTPUT 722 PRESET NORM 20 OUTPUT 722 ACV 30 OUTPUT 722 SETACV ANA 40 OUTPUT 722 MEM FIFO 50 OUTPUT 722 SMATH RES 8 60 OUTPUT 722 MMATH DBM 70 OUTPUT 722 TRIG SGL 80 ENTER 722 A 85 90 PRINT A 100 END Statistics Register SDEV MEAN NSAMP UPPER LOWER 10 OPTION BASE 1 20 DIM Rdgs 20 30 OUTPUT 722 PRESET NORM 40 OUTPUT 722 NRDGS 20 50 OUTPUT 722 MATH STAT 60 ENTER 722 Rdgs 70 OUTPUT 722 RMATH SDEV 80 ENTER
146. ER is selected the A D s aperture waveform is output directly The leading edge of the EXTOUT signal is the response to the event Refer to EXTOUT in Chapter 4 for a detailed description of the above events When a status event sets the SRQ bit in the status register that bit remains set until cleared CSB command for example When specified the EXTOUT SRQ pulse occurs whenever any status event occurs that has been enabled to assert SRQ RQS command The EXTOUT SRQ pulse does not necessarily occur whenever the SRQ bit is set it occurs whenever an enabled status event occurs Query Command The EXTOUT query command returns two responses separated by a comma The first response indicates the currently specified EXTOUT event The second response indicates the polarity Refer to Query Commands near the front of this chapter for more information Chapter 6 Command Reference 179 FIXEDZ Related Commands NRDGS SRQ STB SWEEP TBUFF Example OUTPUT 722 EXTOUT APER SETS EXTOUT EVENT TO APERTURE WAVEFORM FIXEDZ The FIXEDZ command enables or disables the fixed input resistance function for DC voltage measurements When enabled the multimeter maintains its input resistance at 10 megohms for all ranges This prevents a change in input resistance caused by a range change from affecting the DC voltage measurements Syntax FIXEDZ control control The control parameter choices are Numeric Input Resistances control Q
147. ES lt resolution in gt AZERO lt on or off gt In Table 30 you ll see that NPLC and APER commands are somewhat interchangeable The significant difference between these two commands is that NPLC actually uses the power line frequency to establish the integration period for the chosen multiple or submultiple of the line frequency The APER command sets the integration period in fundamental units of seconds from 500 ns to 1s in 100 ns steps Operating at 60 Hz line frequency for example the choice of NPLC 1 is equal to APER 0 016666 Appendix D Optimizing Throughout and Reading Rate _ __ _ SS Figure 44 Shows the om dependency of accuracy Eer 10 reading rate resolution Rig and noise on aperture or NPLC selected Reading ate rdgs s Aperture s Aperture s Table 30 Integration time and query response Command Integration Time Query Response NPLC APER 50 Hz 60 Hz 50 Hz 60 Hz NPLCO 500 ns 500 ns 25 E 6 29 99994 E 6 NPLC 5 10ms 8 333ms 500 E 3 499 99700 E 3 NPLC 1 20ms 16 6667 ms 1 1 NPLC10 200 ms 166 667 ms 10 10 NPLC 11 200 ms 166 667 ms 20 20 For NPLC gt 10 the continuous integration period is equal to the integration period of NPLC 10 but more than one reading is taken The resulting average is output to the display or to the GPIB If NPLC is in the interval from 1 to 10 inclusive then the
148. ET register The value in the OFFSET register is then changed to 3 05 The remaining 20 readings in memory are recalled and the NULL operation is performed on each 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 20 DIMENSION ARRAY FOR 20 READINGS 30 OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 40 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 50 OUTPUT 722 MMATH NULL ENABLE POST PROCESS NULL OPERATION 60 OUTPUT 722 NRDGS 21 21 READINGS PER TRIGGER 70 OUTPUT 722 TRIG SGL TRIGGER READINGS 80 ENTER 722 A RECALL FIRST READING USING IMPLIED READ 90 OUTPUT 722 SMATH OFFSET 3 05 WRITE 3 05 TO OFFSET REGISTER 100 ENTER 722 Rdgs RECALL READINGS USING IMPLIED READ 105 PERFORM NULL OPERATION ON EACH 110 PRINT Rdgs PRINT NULL MODIFIED READINGS 120 END Memory size On a previous multimeter the MSIZE command was used to clear all memory and allocate memory space for readings subprograms and state storage The 3458 accepts the MSIZE command to maintain language compatibility but performs no action since the 3458 s memory allocations are predefined and cannot be changed The MSIZE query command however is useful to determine the total reading memory and the largest unused block of subprogram state memory Syntax MSIZE reading_memory subprogam_memory Remarks As subprogram state memory is used it eventually becomes fragmented into many small blo
149. FREQ max _input _resolution Selects a fixed range or the autorange mode The ranges correspond to the type of input signal specified in the FSOURCE command That is if ACV is the specified input signal the max _input parameter specifies an AC voltage measurement range To select a fixed range you specify max input as the absolute value no negative numbers of the expected peak value of the input signal The multimeter then selects the proper range Refer to the FUNC or RANGE command for tables showing the ranges available for each type of input signal To select the autorange mode specify AUTO for max input or default the parameter In the autorange mode the multimeter samples the input signal before each frequency reading and selects the proper range Power on max _input not applicable Default max _input AUTO The resolution parameter specifies the digits of resolution and the gate time as shown below _resolution also affects the reading rate refer to the Specifications in Appendix A for more information resolution Selects Digits of Parameter Gate Time Resolution 00001 Is 7 0001 100ms 7 001 10ms 6 01 Ims 5 1 100us 4 Power on _resolution not applicable Default _resolution 00001 The reading rate is the longer of period of the input signal the gate time or the default reading timeout of 1 2 seconds Frequency and period measurements are made using the level detection cir
150. For DSAC direct sampled AC coupled and DSDC direct sampled DC coupled all triggering commands are valid but the use of both in the same measurement is not recommended Figure 56 Once the papy y trigger arming and i trigger event conditions are satisfied a burst of aes measurements can bag TIMER 001 NRDGS 200 TIMER digitize a wave form as shown in this example 2s kK TRIG AUTO DELAY 2 TRIG AUTO TARMSGL 0 TARM HOLD TARM HOLD The SSRC command offers you either internal level triggering or synchronization with the external trigger In the subsampling mode the SSRC EXT calculates the number of external triggers it needs to accomplish the measurement you specify with the SWEEP command For example if you want to capture a wave form with 100 ns time resolution for 4096 readings SWEEP 100E 9 4096 the 3458A multiplies the number of readings by the time interval and divides by the minimum time between samples Delay can be used in conjunction with external trigger synchronization to window your measurement to examine the parts of the wave form you want to see in detail For example consider using the 3458A as a broadband phase gain meter with a 3325A source to measure the transfer function ofa passband filter over a frequency range of 0 5 to 5 MHz Refer to Figure 57 The highest frequency is 5 MHz so the minimum time between samples for entire band is 100 ns for two samples per Appendix E High Resol
151. G ENTER 722 Rdgs ENTER READINGS PRINT Rdgs PRINT READINGS END Chapter 4 Making Measurements 87 10 OPTION BASE 1 20 DIM Rdgs 10 The following example uses EXT as the sample event The trigger event is synchronous selected by the PRESET NORM command The number of readings per trigger event is set to 10 When the controller executes line 50 the synchronous event occurs which enables the sample event EXT Upon the arrival of a negative edge transition on the Ext Trig terminal the multimeter takes a single reading which is transferred to the controller A second negative edge transition initiates the second reading which is transferred to the controller This sequence continues until all 10 readings are completed and transferred to the controller COMPUTER ARRAY NUMBERING STARTS AT 1 DIMENSION ARRAY FOR READINGS 30 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 NRDGS 10 EXT 10 READINGS TRIGGER EXTERNAL SAMPLE EVENT 50 ENTER 722 Rdgs ENTER READINGS 60 PRINT Rdgs 70 END Note External Trigger Buffering Event Combinations PRINT READINGS Refer to the EXTOUT Signal later in this chapter for examples showing how to synchronize the multimeter to an external scanning device Trigger buffering corrects for an error TRIGGER TOO FAST that can occur when using the external EXT trigger arm trigger or sample event With trigger buffering disabled any
152. G The following procedures are to be performed by qualified service trained personnel only To avoid personal injury do not perform the procedures unless you are qualified to do so Tools Required You need 1 1 Pozidriv screwdriver 2 TX 15 Torx driver 3 TX10 Torx driver Procedure The procedure to install the lockout kit is separated into the following Covers Removal Procedure e Guard Pushrod Removal Procedure Front Rear Pushrod Removal Procedure e Switch Cap Installation Procedure e Covers Installation Procedure Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches 311 Covers Removal Do the following Procedure 1 Remove any connections to the 3458 2 Remove ac power from the 3458 3 Refer to Figure 35 Turn the instrument so its right side faces you as seen from the front 1 RIGHT SIDE HANDLE STRAP SCREW 2 RIGHT SIDE HANDLE STRAP Figure 35 3458 Right side 4 Use the 1 pozidriv to remove the right side handle strap screws Then remove the strap 5 Refer to Figure 36 Turn the instrument so its left side faces you 6 Use the 1 pozidriv to remove the left side handle strap screws Then remove the strap 7 Use the TX10 Torx driver to remove the top and bottom covers ground screws as shown in Figure 37 8 Refer to Figure 38 Turn the instrument so its back faces you 9 Use the T X15 Torx driver to remove the rear bezel screws Then remove the
153. GS 20 ENTER 722 A BS 30 PRINT AS BS 40 END Responses to query commands are always output over the GPIB in the ASCII output format regardless of the specified output format Following the query response the output format returns to that previously specified SINT DINT SREAL DREAL or ASCII 154 Chapter 6 Command Reference Commands by Functional Group Commands by Functional Group The following is a list of all commands recognized by the multimeter categorized by function measurement functions digitizing A D converter etc Measurement Functions SWEEP Math ACDCI TARM MATH ACDCV TBUFF MMATH ACI TIMER RMATH ACV TRS OT SMATH DCI DCV Reading Memory Keyboard DSAC MCOUNT DEEKEY DSDC MEM LOCK FREQ MFORMAT MENU FUNC MSIZE OHM RMEM Bus OHMF PER Program Memory are SSAC CALL SRO SSDC COMPRESS CONT Measurement Related DELSUB System ACBAND PAUSE BEEP ARANGE SCRATCH DEFEAT AZERO SUB Bee eras SUBEND PRESET DIG FAST or NORM FSOURCE State Memory oe LFILTER PURGE TONE a DIG FAST or NORM DANE or 5 RANGE or R Tin Display RATIO DISP SETACV NDIG SESAR A D Converter TERM AFER Calibration Test LFREQ RCAL a LINE Digitizing NPLC CAL DSAC RES CAL DSDC CALNUM LEVEL CALSTR LFILTER Status REV SLOPE Sop SCAL NRDGS RQS SECURE PRESET DIG amp FAST SRQ TEMP SSAC STB TEST SSDC SSPARM Input Output GPIB Commands SSRC END ABORT IO SWEEP INBUF CLEAR TIMER ISCALE LOCAL OFORMAT LOCAL LOCKOUT Triggerin
154. H Syntax Remarks Example LOCK reference frequency to the measured value Related Commands LFREQ 10 OUTPUT 722 LINE MEASURES THE LINE FREQUENCY 20 ENTER 722 A ENTERS RESPONSE INTO COMPUTER S A VARIABLE 30 PRINT A PRINTS RESPONSE 40 END Lockout Enables or disables the multimeter s keyboard LOCK control control The control parameter choices are Numeric control Query Parameter Equiv Description OFF 0 Enables the keyboard normal operation ON 1 Disables the keyboard pressing keys has no affect Power on control OFF Default control ON The LOCK command is accessible from the front panel s alphabetic command directory However executing the LOCK command from the front panel has no effect After disabling the keyboard you can only enable it from the controller or by cycling power The LOCK command disables the multimeter s Local key e Query Command The LOCK query command returns the present LOCK mode Refer to Query Commands near the front of this chapter for more information Related Commands LOCAL LOCKOUT GPIB command OUTPUT 722 LOCK ON DISABLES THE KEYBOARD The MATH command enables or disables real time math operations Syntax MATH operation_a operation_b Chapter 6 Command Reference 193 MATH operation The operation parameter choices are operation Parameter OFF CONT CTHRM FILTER FTHRM NULL PERC PFAIL RMS SCA
155. HEN GOTO 30 LOOPS FOR EACH ERROR 70 END External Output Specifies the event that will generate a signal on the rear panel Ext Out connector EXTOUT signal This command also specifies the polarity of the EXTOUT signal EXTOUT event polarity 178 Chapter 6 Command Reference EXTOUT event The event choices are polarity Remarks Numeric event Query Parameter Equiv Description OFF 0 None EXTOUT is disabled ICOMP 1 Input complete 1us pulse after A D converter has integrated each reading or for direct or sub sampling after the track and hold has acquired the input signal ONCE 2 Outputs a 1us pulse upon execution of the EXTOUT ONCE command the event then becomes OFF APER 3 Aperture waveform a level indicating when the A D converter is making a measurement BCOMP 4 Burst complete 1s pulse following a group of readings SRQ 5 Status event occurred lus pulse whenever a status register event occurs that has been enabled to assert the GPIB SRQ See second Remark below RCOMP 6 Reading complete lus pulse after each reading Power on event ICOMP Default event ICOMP Specifies the polarity of the EXTOUT signal The choices are Numeric polarity Query Parameter Equiv Description NEG 0 Generates a low going TTL signal POS 1 Generates a high going TTL signal Power on polarity NEG Default polarity NEG e All events except APER generate a 1 us pulse on the EXTOUT connector If AP
156. INTEGRATION TIME 100 OUTPUT Dvm OFORMAT SINT SINT OUTPUT FORMAT 110 OUTPUT Dvm NRDGS Num_readings 130000 READINGS TRIGGER AUTO 115 SAMPLE EVENT DEFAULT VALUE 120 TRANSFER Dvm TO Int rdgs WAIT SYN EVENT TRANSFER READINGS INTO 125 SINT NO DATA 140 ENTER Dvm S 170 R ABS Rdgs I 150 FOR I 1 TO Num_readings 160 Rdgs I Int_rdgs I CONVERT EACH INTEGER READING TO REAL 165 FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE 121 INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED 130 OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR SINT FORMAT ENTER SCALE FACTOR USE ABSOLUTE VALUE TO CHECK FOR OVLD 180 IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE 190 Rdgs 1I Rdgs I S MULTIPLY READING TIMES SCALE FACTOR 200 Rdgs I OROUND Rdgs I 4 ROUND TO 4 DIGITS 210 NEXT I 220 END Determining the Reading Rate When using the TIMER sample event or the SWEEP command the reading rate is simply the reciprocal of the specified interval between readings assuming the TRIGGER TOO FAST error does not occur For example if the TIMER interval is specified as 1E 4 the reading rate is 1 1 E 4 10 000 readings per second When using another sample event you can determine the reading rate by specifying a large number of readings per trigger specifying an output pulse after each reading EXT
157. INTEGRATION TIME 722 ACBAND 10E3 20E3 SIGNAL BETWEEN 10kHz AND 20kHz 722 NRDGS 100 AUTO 100 READINGS TRIGGER AUTO SAMPLE EVENT 722 TARM SGL TRIGGER READINGS The following program measures AC current at a fast rate This program uses the default delay time You can achieve faster reading rates by specifying a shorter delay time the resulting settling time however may not produce accurate measurements You can also achieve unspecified faster reading rates by specifying less integration time in line 50 This program can be adapted to AC DC current by using the ACDCI command instead of the ACI command in line 40 722 PRESET FAST TARM SYN TRIG AUTO 722 MFORMAT SINT SINT MEMORY FORMAT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 722 ACI 100E 3 AC CURRENT 100mV RANGE 722 NPLC 0 1 0 1 PLC INTEGRATION TIME 722 ACBAND 10E3 20E3 SIGNAL BETWEEN 10kHz AND 20kHz 722 NRDGS 100 AUTO 100 READINGS TRIGGER AUTO SAMPLE EVENT 722 TARM SGL TRIGGER READINGS The following program measures frequency at a fast rate This program can Example be adapted to measure period by using the PER command instead of the OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT END FREQ command in line 40 722 PRESET FAST TARM SYN TRIG AUTO 722 MFORMAT SREAL SINGLE REAL MEMORY FORMAT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 1221 FREO 105 p17 FREQUENCY 10V RANGE 100us GATE TIME 722 ACBAND 10E3 20
158. IONS OUTPUT 722 RQS 0 DISABLES ALL CONDITIONS Recall State Recalls a stored state from memory and configures the multimeter to that state States are stored using the SSTATE command RSTATE name name State name A state name may contain up to 10 characters The name can be alpha alphanumeric or an integer in the range of 0 to 127 Refer to the SSTATE command for details Chapter 6 Command Reference 231 SCAL SCAL SCRATCH SECURE Remarks Example Syntax Remarks Example Syntax Power on name none Default name 0 Whenever the multimeter s power is removed the present state is stored in state 0 After a power failure the multimeter can be configured to its previous state by executing RSTATE 0 If the NULL real time math operation was enabled in a stored state after recalling the state the first reading is placed in the OFFSET register refer to NULL in Chapter 4 for more information From the front panel you can review the names of all stored states by pressing the Recall State key and by using the up and down arrow keys When you have found the desired state press the Enter key to recall that state e Related Commands MSIZE PURGE SCRATCH SSTATE OUTPUT 722 RSTATE B2 RECALLS STORED STATE NAMED B2 This is a calibration command Refer to the 3458A Calibration Manual for details Clears all subprograms and stored states from memory SCRATCH Individual subprograms ca
159. IVE INTERVAL 1 RANSFER Dvm TO Int_samp WAIT SYN EVENT 01 TOT 11 151 200 30E 400 50E 70 be 80 90 200 210 INTEGER ARRAY SINCE THE COMPUTER S ASSIGN BUFFER I O PATH NAME SUB SAMPLING SINT 000 SAMPLES TRANSFER READINGS INTO INTEGER FORMAT IS THE SAME AS NG NG TEGE LE INTEGER OVER R ABS Samp I USE ABSOLUTE VALUE IF R gt 32767 THEN PRINT OVLD ees Samp I Samp I S MU Samp I DROUND Samp I 4 IRO 220NEXT I 229 230Inc N1 N2 TOTAL NUMBER O 240K 1 250FOR I 1 TO N1 260 270 280 290 300 310 L I FOR J 1 TO N3 Wave_form L Samp K K K 1 L L Inc NEXT J 320NEXT I 330F 340 350 360 370 380 390 400N OR I N1 1 TO N1 N2 L I FOR J 1 TO N3 1 Wave_form L Samp K K K 1 L L Inc NEXT J EXT I 410END F OVLD PRINT UND TO 4 DIGIT OVE LTIPLY READING TI S SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED UTPUT Dvm I SCALE QUERY SCALE FACTOR NTER Dvm S ENTER SCALE FACTOR UTPUT Dvm SSPARM QUERY SUB SAMPL NTER Dvm N1 N2 N3 ENTER SUB SAMPL 60FOR I 1 TO Num_samples Samp I Int_samp I CONVERT EACH INT FORMAT NECESSARY TO PREVENT POSSIB FOR SINT FORMAT PARAMETERS PARAMETERS R READING TO REAL FLOW ON NEXT LINE TO CHECK FOR OVLD RLOAD MESSAGE ES SCALE FACTOR F BURSTS Chapter 5 Digitizing 145 Viewing Sampled Data 146 The program on the following
160. Keysight 3458A Multimeter KEYSIGHT User s Guide TECHNOLOGIES NOTICE This document contains references to Agilent Technologies Agilent s former Test and Measurement business has become Keysight Technologies For more information go to www keysight com KEYSIGHT TECHNOLOGIES U S Government Restricted Rights The Software and Documentation have been developed entirely at private expense They are delivered and licensed as commercial computer software as defined in DFARS 252 227 7013 Oct 1988 DFARS 252 211 7015 May 1991 or DFARS 252 227 7014 Jun 1995 as a commercial item as defined in FAR 2 101 a or as Restricted computer software as defined in FAR 52 227 19 Jun 1987 or any equivalent agency regulation or contract clause whichever is applicable You have only those rights provided for such Software and Documentation by the applicable FAR or DFARS clause or the Keysight standard software agreement for the product involved 3458A Multimeter User s Guide Documentation History All Editions and Updates of this manual and their creation date are listed below The first Edition of the manual is Edition 1 The Edition number increments by 1 whenever the manual is revised Updates which are issued between Editions contain replacement pages to correct or add additional information to the current Edition of the manual Whenever a new Edition is created it will contain all of the Update informa
161. L format conforms to IEEE 754 specifications This format has 32 bits 4 bytes per reading as follows S EEE EEEE E MMM MMMM MMMM MMMM MMMM MMMM byte 0 byte 1 byte 2 byte 3 Where S sign bit 1 negative 0 positive E base two exponent biased by 127 to decode these 8 bits subtract 127 from their decimal equivalent M mantissa bits those right of the radix point There is an implied most significant bit MSB to the left of the radix point This bit is always assumed to be 1 This provides an effective precision of 24 bits with the least significant bit right most weighted 2 23 Another way to evaluate this mantissa is to convert these 24 bits MSB assumed 1 to an integer and then multiply by 223 The value of a number in the SREAL format is calculated by 1 x mantissa x 2 xPonent This example resolves the decimal equivalent of the following SREAL formatted number SEEEEEEE EMMMMMMM MMMMMMMM MMMMMMMM 10111011 11001000 01001000 10010000 The sign bit S is set 1 this indicates that the number is negative The base two s exponent 01110111 evaluates to 2649542442242 429 119 Since the exponent is biased by 127 the real value is exponent 127 119 127 8 The mantissa 1 10010000100100010010000 MSB assumed 1 evaluates to 14274244294 21249164919 156471443177 Evaluating the mantissa at the byte level instead of the bit level byte 1 byte 2 byte 3 byte 1 byte 2
162. LE STAT CTHRM2 K CTHRM10 K FTHRM2 K FTHRM10 K Numeric Equiv 0 1 Description Disables all enabled real time math operations Enables the previous math operation To resume two math operations send MATH CONT CONT Result temperature Celsius of a 5kQ thermistor 40653B Function must be OHM or OHMF 10kQ range or higher Result 20 x Log o reading REF register The REF register is initialized to 1 yielding dBV Result 10 x logyo reading RES register I1mW Function must be ACV DCV or ACDCV Result output of exponentially weighted digital low pass filter Response is set by DEGREE register Result temperature Fahrenheit of a 5kQ thermistor 40653B Function must be OHM or OHMF 10kQ range or higher Result reading OFFSET register The OFFSET register is set to first reading after that you can change it Result reading PERC register PERC register x 100 Reading vs MAX and MIN registers Result squares reading applies FILTER operation takes square root Result reading OFFSET register SCALE register Performs statistical calculations on the present set of readings and stores results in these registers SDEV standard deviation MEAN average of readings NSAMP number of readings UPPER largest reading LOWER smallest reading Result temperature Celsius of a 2kQ thermistor 40653A Function must be OHM or OHMF Result temperature Celsius of a 1
163. LES 90 PRINT A B C PRINTS READINGS 100 END Request Service Enables one or more status register conditions When a condition is enabled and that condition occurs it sets the GPIB SRQ line true Syntax RQS value value Chapter 6 Command Reference RSTATE Remarks Examples Syntax RSTATE You enable a condition by specifying its decimal weight as the value parameter For more than one condition specify the sum of the weights The conditions and their weights are Decimal Bit Weight Number Enables Condition 1 0 Program Memory Execution Completed 2 1 Hi or Lo Limit Exceeded 4 2 SRQ Command Executed 8 3 Power On SRQ 16 4 Ready for Instructions 32 5 Error Consult Error Register 64 6 Service Requested you cannot disable this bit 128 7 Data Available Power on value If Power On SRQ was enabled when power was removed value 8 otherwise value 0 Default value 0 no conditions enabled e You can control the errors that will set bit 5 with the EMASK command The power on SRQ bit is stored in continuous memory All other bits are cleared at power on e Query Command The RQS query command returns the weighted sum of all enabled bits in the status register Related Commands CSB SPOLL GPIB command STB OUTPUT 722 RPS 4 ENABLES THE FRONT PANEL SRQ CONDITION OUTPUT 722 RQS 40 ENABLES POWER ON SRQ 8 amp ERROR 32 CONDITIONS OUTPUT 722 RQS 255 ENABLES ALL CONDIT
164. ME NULL MATH OPERATION UTPUT 722 TRIG SGL TRIGGER 1 READING STORED IN OFFSET O O O 60 OUTPUT 722 SMATH OFFSET 3 05 WRITE 3 05 TO OFFSET REGISTER O O E 70 OUTPUT 722 NRDGS 20 20 READINGS PER TRIGGER 80 OUTPUT 722 TRIG SYN SYN TRIGGER EVENT 90 ENTER 722 Rdgs SYN EVENT ENTER NULL CORRECTED READINGS 100 PRINT Rdgs PRINT NULL CORRECTED READINGS 110 END Memory Count Query Returns the total number of stored readings MCOUNT Related Commands MEM MFORMAT MSIZE RMEM 10 OUTPUT 722 MCOUNT RETURNS TOTAL NUMBER OF STORED READINGS 20 ENTER 722 A ENTERS RESPONSE INTO A VARIABLE 30 PRINT A PRINTS RESPONSE 40 END Memory Enables or disables reading memory and designates the storage mode MEM mode mode The mode parameter choices are Numeric mode Query Parameter Equiv Description OFF 0 Stops storing readings stored readings stay intact LIFO 1 Clears reading memory and stores new readings LIFO last in first out 196 Chapter 6 Command Reference MENU Remarks Example MENU Numeric mode Query Parameter Equiv Description FIFO 2 Clears reading memory and stores new readings FIFO first in first out CONT 3 Keeps memory intact and selects previous mode if there was no previous mode FIFO is selected Power on mode OFF Default mode ON e In the high speed mode when reading memory is enabled in the FIFO mode and becomes full the trigger arm
165. MHz Programming the 3458A for direct or subsampled sequential digitizing using the track and hold path is simple Only one command is required For example DSAC provides direct sampling AC coupled or SSAC provides sequential sampling AC coupled These commands automatically use default parameters that can be changed Signal ue 175 ns Latency Sample window Z hs External trigger event Figure 53 Capturing the pulse amplitude of narrow pulses requires the use of the 12 MHz track and hold path Note the minimum time between sample acquisition and trigger event is 175 nanoseconds Capturing the Data 352 The 3458A can be triggered to commence the measurement cycle by the level and slope of the input signal by a zero voltage level crossing of the power line by the GET group execute trigger command on the GPIB by an external TTL signal by an internally generated trigger signal for burst measurements this can be paced and by the computer asking for a reading The 3458A provides all the tools you need to catch the signal of interest by offering three levels of triggering and up to eight conditions to satisfy including the wave form s level and slope The hierarchy of trigger levels is trigger arming TARM trigger TRIG and number of readings per trigger NRDGS Focused at Appendix E High Resolution Digitizing With the 3458A digitizing two additional commands are used for direct sampling and s
166. MODE SINT MEMORY FORMAT 10000 READINGS TRIGGER AUTO SAMPLE EVENT START TIMER TRIGGER READINGS STOP TIMER 120 PRINT Readings per second Num_readings T1 TO 125 130 END PRINT READINGS PER SECOND If you are transferring multiple readings across the bus instead of using reading memory you can use the SYN synchronous trigger arm or trigger event which also holds the bus until all readings are complete and transferred and time the controller s ENTER or TRANSFER statement This is shown in the following program the synchronous trigger arm event is selected by the PRESET FAST command in line 50 10 REAL Num_readings 20 Num_readings 300000 30 ASSIGN Dvm TO 722 40 ASSIGN Buffer TO BUFFER 2 Num_readings 50 OUTPUT Dvm PRESET FAST 55 60 OUTPUT Dvm NPLC 0 70 OUTPUT Dvm OFORMAT SINT 80 OUTPUT Dvm NRDGS Num_readings AUTO 85 300000 READINGS TRIGGER AUTO SAMPLE EVENT 90 TO TIMEDATE 100 TRANSFER Dvm TO Buffer WAIT 110 T1 TIMEDATE CREATE ARRAY NUMBER OF READINGS 300000 ASSIGN MULTIMETER ADDRESS ASSIGN BUFFER I O PATH NAME DCV 10V RANGE DINT OUTPUT FORMAT TARM SYN TRIG AUTO MINIMUM INTEGRATION TIME SINT OUTPUT FORMAT BEGIN TIMING READINGS SYN EVENT TRANSFER READINGS STOP TIMING READINGS 120 PRINT READINGS PER SECOND 11 Num_readings T1 T0O 125 130 END PRINT READINGS PER SECOND Note The time required to retrieve the scale fa
167. MORY FIFO MODE 30 OUTPUT 722 TR1IG EXT TRIGGER EVENT EXTERNAL 40 OUTPUT 722 EXTOUT BCOMP NEG BURST COMPLETE EVENT LOW GOING TTL 50 OUTPUT 722 NRDGS 15 AUTO 15 READINGS PER CHANNEL 55 CONFIGURE EXTERNAL SCANNER 60 OUTPUT 709 SADV EXTIN ADVANCE SCANNER ON MULTIMETER S EXTOUT SIGNAL 70 OUTPUT 709 CHCLOSED EXT OUTPUT LOW GOING PULSE AFTER EACH CLOSURE 80 OUTPUT 709 SCAN 201 206 SCAN CHANNELS 01 06 ON SCANNER IN SLOT 200 85 AND ADVANCE TO CHANNEL 01 STARTING THE SCAN 90 END Chapter 4 Making Measurements 113 Input Complete The input complete event ICOMP event is similar to the RCOMP event in that it produces a lus pulse for each reading However when the ICOMP event is specified the pulse occurs when the A D converter has finished integrating the input signal but before the reading is complete see Figure 20 The ICOMP event can be used with an external scanner when making a single reading per scanner channel This event is especially important when using a slower relay type scanner Since the ICOMP event occurs before the reading is complete it advances the scanner sooner than would the RCOMP event The following program uses the ICOMP event to make one reading on each of 6 scanner channels Notice that line 40 enables trigger buffering This prevents the multimeter from generating the TRIGGER TOO FAST error should the scanner output a channel closed pulse before the present reading is complete C
168. MP OFF The following program measures DC voltage at the fastest possible rate gt Example 100k readings per second The readings are stored in reading memory OUTPUT 722 PRESET FAST DCV 10V RANGE TARM SYN TRIG AUTO OUTPUT 722 APER 1 4E 6 LONGEST INTEGRATION TIME POSSIBLE FOR gt 100K READINGS PER SECOND OUTPUT 722 MFORMAT SINT SINT MEMORY FORMAT OUTPUT 722 MEM FIFO ENABLE READING MEMORY OUTPUT 722 NRDGS 10000 AUTO 10000 READINGS TRIGGER AUTO SAMPLE EVENT OUTPUT 722 TARM SGL TRIGGER READINGS END OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT 22r 722 722 722 The following program measures 2 wire ohms at the fastest possible rate gt 100k readings per second This program can be adapted to 4 wire ohms by using the OHMF command instead of the OHM command in line 50 PRESET FAST DCV 10V RANGE TARM SYN TRIG AUTO APER 1 4E 6 LONGEST INTEGRATION TIME POSSIBLE FOR gt 100K READINGS PER SECOND MFORMAT SINT SINT MEMORY FORMAT MEM FIFO ENABLE READING MEMORY OHM 100E3 2 WIRE OHMS 100K Q RANGE NRDGS 10000 AUTO 10000 READINGS TRIGGER AUTO SAMPLE EVENT Chapter 4 Making Measurements 105 70 OUTPUT 722 TARM SGL TRIGGER READINGS 80 END High Speed DCI Example The following program measures DC current at the fastest possible rate 10 20 25 30 40 50 60 70 80 OUTPUT 722 PRESET FAST DCV 10V RANGE TARM SYN TRIG AUTO OUTPUT 722 APER 1 4E 6 I LONGEST INTEGRATIO
169. N TIME POSSIBLE FOR MAXIMUM READING RATE OUTPUT 722 MFORMAT SINT SINT MEMORY FORMAT OUTPUT 722 MEM FIFO ENABLE READING MEMORY OUTPUT 722 DCI 100E 3 DC CURRENT 100mA RANGE OUTPUT 722 NRDGS 5000 AUTO 15000 READINGS TRIGGER AUTO SAMPLE EVENT OUTPUT 722 TARM SGL TRIGGER READINGS END Fast Synchronous The following program measures AC voltage using the synchronous method ACV ACDCV Example atthe fastest possible rate approximately 10 readings per second This program can be adapted to AC DC voltage by using the ACDCV command instead of the ACV command in line 50 10 OUTPUT 722 PRESET FAST TARM SYN TRIG AUTO 20 OUTPUT 722 MFORMAT SINT SINT MEMORY FORMAT 30 OUTPUT 722 MEM FIFO ENABLE READING MEMORY 40 OUTPUT 722 SETACV SYNC SYNCHRONOUS AC MEASUREMENT METHOD 50 OUTPUT 722 ACV 10 2 AC VOLTS 10V RANGE 2 RESOLUTION 60 OUTPUT 722 ACBAND 5E3 8E3 SIGNAL BETWEEN 5kHz AND 8kHz 70 OUTPUT 722 NRDGS 20 AUTO 20 READINGS TRIGGER AUTO SAMPLE EVENT 80 OUTPUT 722 TARM SGL TRIGGER READINGS 90 END Fast Random The following program measures AC voltage using the random method at ACV ACDCV Example the fastest possible rate approximately 45 readings per second This program can be adapted to AC DC voltage by using the ACDCV command instead of the ACV command in line 50 10 OUTPUT 722 PRESET FAST TARM SYN TRIG AUTO 20 OUTPUT 722 MFORMAT SINT SINT MEMORY FORMAT 30 OUTPUT 722 MEM FIFO
170. ND Rdgs I 4 ROUND TO 4 DIGITS 180NEXT I 190END DINT Example The following program is similar to the preceding program except that it takes 50 readings and transfers them to the computer using the DINT format 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_readings 1 J K DECLARE VARIABLES 30 Num_readings 50 NUMBER OF READINGS 50 40 ALLOCATE REAL Rdgs 1 Num_readings CREATE ARRAY FOR READINGS 50 ASSIGN Dvm TO 722 ASS1GN MULTIMETER ADDRESS 60 ASSIGN Buffer TO BUFFER 4 Num_ readings ASSIGN BUFFER I O PATH NAME 70 OUTPUT Dvm PRESET NORM RANGE 10 FORMAT DINT NRDGS Num_readings 75 TARM AUTO TRIG SYN DCV 10V RANGE DINT OUTPUT FORMAT NRDGS 50 AUTO 80 TRANSFER Dvm TO Buffer WAIT SYN EVENT TRANSFER READINGS 90 OUTPUT Dvm 1 SCALE QUERY SCALE FOR DINT 100ENTER Dvm S ENTER SCALE FACTOR 110FOR I 1 TO Num_readings 120ENTER Buffer USING W W J K ENTER ONE 16 BIT 2 s COMPLEMENT 121 WORD INTO EACH VARIABLE J AND K STATEMENT TERMINATION NOT 125 REQUIRED W ENTER DATA AS 16 BIT 2 S COMPLEMENT INTEGER 130Rdgs I J 65536 K 65536 K lt 0 CONVERT TO REAL NUMBER 140R ABS Rdgs I USE ABSOLUTE VALUE TO CHECK FOR OVLD 150IF R gt 2147483647 THEN PRINT OVLD IF OVERLOAD OCCURRED PRINT MESSAGE 160Rdgs I Rdgs I S APPLY SCALE FACTOR 170Rdgs I DROUND Rdgs I 8 ROUND CONVERTED READING 180PRINT Rdgs I PRINT READINGS 190NEXT I 200END Chapter 4 Makin
171. NORM PRESET NRDGS 1 AUTO DCV 10 OUTPUT 722 MATH NULL ENABLE REAL TIME NULL MATH OPERATION OUTPUT 722 TRIG SGL TRIGGER 1 READING STORED IN OFFSET OUTPUT 722 SMATH OFFSET 3 05 WRITE 3 05 TO OFFSET REGISTER OUTPUT 722 NRDGS 20 20 READINGS PER TRIGGER OUTPUT 722 TRIG SYN SYN TRIGGER EVENT ENTER 722 Rdgs SYN EVENT ENTER NULL CORRECTED READINGS 90 100 PRINT Rdgs 110 END 10 OPTION BASE 1 20 DIM Rdgs 20 30 OUTPUT 722 PRESET NORM 40 OUTPUT 722 MEM FIFO PRINT NULL CORRECTED READINGS The following program performs the post process NULL operation on 20 readings After executing the MMATH NULL command 21 readings are taken and stored in reading memory in FIFO mode Line 80 recalls the first reading taken which is stored in the OFFSET register The value in the OFFSET register is then changed to 3 05 The remaining 20 readings in memory are recalled and the NULL operation is performed on each COMPUTER ARRAY NUMBERING STARTS AT 1 DIMENSION ARRAY FOR 20 READINGS PRESET NRDGS 1 AUTO DCV 10 ENABLE READING MEMORY FIFO MODE Chapter 4 Making Measurements 50 OUTPUT 722 MMATH NULL ENABLE POST PROCESS NULL OPERATION 60 OUTPUT 722 NRDGS 21 21 READINGS PER TRIGGER 70 OUTPUT 722 TRIG SGL TRIGGER READINGS 80 ENTER 722 A RECALL FIRST READING USING IMPLIED READ 90 OUTPUT 722 SMATH OFFSET 3 05 WRITE 3 05 TO OFFSET REGISTER 100 ENTER 722 Rdgs RECALL READINGS
172. Note Chapter 5 Digitizing When digitizing it is important to begin sampling at some defined point on the input signal such as when the signal crosses zero volts or when it reaches the midpoint of its positive or negative peak amplitude Level triggering allows you to specify when with respect to voltage and slope to begin sampling For example Figure 26 shows sampling beginning as the input signal crosses OV with a positive slope 5V OV DV Figure 26 Level triggering at zero crossing positive slope For DCV and direct sampling level triggering can be used as the trigger event TRIG LEVEL command or the sample event NRDGS n LEVEL command For sub sampling level triggering can be used as the sync source event only the sync source event is discussed later in this chapter under Sub Sampling The program examples in this section use the DCV method of digitizing and the 10V range Refer to DCV Digitizing Direct Sampling and Sub Sampling later in this chapter for complete programs showing specific information on how to use level triggering with each digitizing method The LEVEL command specifies the level triggering voltage as a percentage ofthe measurement range The ranges are shown later in this chapter under the discussions for each digitizing method The LEVEL command also specifies the coupling AC or DC to the level detection circuitry The coupling of the input signal can affect the level trigger cou
173. OQ 0 075 V 10 3 2 1 1 mA 1 2000000 100 pA 100 Q 0 100 V 10 2 2 1 5 10 mA 12 000000 1nA 10 Q 0 100 V 10 2 2 1 100 mA 120 00000 10nA 1Q 0 250 V 2542 2 1 1A 1 0500000 100 nA 0 1 2 lt 1 5 V 25 3 2 2 Accuracy 3 ppm Reading ppm Range Range 24 Hour 4 90 Day 5 1 Year 2 Year gt 100 nA 10 400 30 400 30 400 35 400 1 pA 10 40 15 40 20 40 25 40 10 nA 10 7 15 10 20 10 25 10 6 100 pA 10 6 15 8 20 8 25 8 1 mA 10 4 15 5 20 5 25 5 10 mA 10 4 15 5 20 5 25 5 100 mA 25 4 30 5 35 5 40 5 1A 100 10 100 10 110 10 115 10 Settling Characteristics Measurement Considerations For first reading or range change error add 001 Keysight recommends the use of PTFE cable or other of input current step additional error Reading high impedance low dielectric absorption cable for low settling times can be affected by source impedance current measurements Current measurements at rates and cable dielectric absorption characteristics lt NPLC 1 are subject to potential noise pickup Care Additional Errors must be taken to provide adequate shielding and guarding to maintain measurement accuracies Selected Reading Rates NPLC Aperture Digits Readings Sec 0 0001 1 4 us 4 5 2 300 0 0006 10 us 5 5 1 350 3 0 01 167us 65 157 l 2 0 1 1 67ms8 6 5 108 z 1 16 6ms8 7 5 26 8 10 0 16688 75 3 100 7 5 18 min Maximum Input Rated Input Non Destructive oe ee ee ee ae Integration Time in Number Power Line Cycles Cae p a p NPLC log scale Guard to 500 V pk 1000 V
174. OUT RCOMP command and connecting an electronic frequency counter to the multimeter s Ext Out connector The frequency displayed on the counter is the reading rate expressed in readings per second Another method uses the controller to time a number of readings initiated by the TARM SGL or TRIG SGL command With the input buffer disabled INBUF OFF the SGL event holds the GPIB bus until the readings are complete This means that the time required to execute the TARM SGL or TRIG SGL command is the total time of the measurement For example the following program stores readings in reading memory times TARM SGL for 10000 readings divides 10000 by the total time and displays readings per second The TIMEDATE command lines 90 and 110 applies to Hewlett Packard Series 200 300 computers using BASIC language Refer to your computer operating manuals for more information on how to use you Chapter 4 Making Measurements 109 computer s timer 10 REAL Num_readings 20 Num_readings 10000 30 ASSIGN Dvm to 722 40 OUTPUT Dvm PRESET FAST 45 50 OUTPUT Dvm NPLC 0 60 OUTPUT Dvm MEM FIFO 70 OUTPUT Dvm MFORMAT SINT 80 OUTPUT Dvm NRDGS Num_readings AUTO 85 90 TO TIMEDATE 100 OUTPUT Dvm TARM SGL 110 T1 TIMEDATE CREATE ARRAY NUMBER OF READINGS 10000 ASSIGN MULTIMETER ADDRESS DCV 10V RANGE DINT MEM FORMAT FAST READINGS TARM SYN TRIG AUTO MINIMUM INTEGRATION TIME 500ns ENABLE READING MEMORY FIFO
175. OVERLOAD OCCURRED PRINT MESSAGE 60 Rdgs 1I Rdgs I S APPLY SCALE FACTOR 70 Rdgs I DROUND Rdgs I 8 ROUND CONVERTED READING 80 PRINT Rdgs I PRINT READINGS 90 NEXT I 200 END SREAL Format The following program shows how to convert 10 readings output in the SREAL format 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_readings DECLARE VARIABLE 30 Num_readings 10 NUMBER OF READINGS 10 40 ALLOCATE REAL Rdgs 1 Num readings CREATE ARRAY FOR READINGS 50 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 60 ASSIGN Buffer TO BUFFER 4 Num_ readings ASSIGN BUFFER I O PATH NAME Chapter 6 Command Reference OFORMAT 70 OUTPUT Dvm PRESET NORM OFORMAT SREAL NRDGS Num_readings 75 TRIG SYN SREAL OUTPUT FORMAT 1 PLC DCV AUTORANGE 10 READINGS 80 TRANSFER Dvm TO Buffer WAIT SYN EVENT TRANSFER READINGS 90 FOR I 1 TO Num_readings 00 ENTER Buffer USING B A B C D ENTER ONE 8 BIT BYTE INTO 01 EACH VARIABLE STATEMENT TERMINATION NOT REQUIRED B ENTER ONE 05 8 BIT BYTE AND INTERPRET AS AN INTEGER BETWEEN 0 AND 255 10 S 1 CONVERT READING FROM SREAL 20 IF A gt 127 THEN S 1 CONVERT READING FROM SREAL 30 IF A gt 127 THEN A A 128 CONVERT READING FROM SREAL 40 A A 2 127 CONVERT READING FROM SREAL 50 IF B gt 127 THEN A A 1 CONVERT READING FROM SREAL 60 IF B lt 127 THEN B B 128 CONVERT READING FROM SREAL 70 Rdgs 1 S B 65536 C 256 D 2 A 23
176. P anie Veini iiei iie eNA 254 TERM errar E E coud A R TR 254 TEST iuran E ate et RE a 255 TIMER reeniri neee 255 TONE patanen enee toads REA Aia 256 TRIG aa hei a a ORAA N 256 150 Chapter 6 Command Reference Introduction Chapter 6 Command Reference Introduction The first part of this chapter discusses the multimeter s language This includes core commands command termination parameters query commands lists of commands by functional group and a table relating commands to measurement functions The remainder of the chapter consists of detailed descriptions of each command listed in alphabetical order by command Before using this chapter you should read about the multimeter functions you need to use in the preceding tutorial chapters Chapters 2 3 4 and 5 The tutorial chapters describe each multimeter function and identify which commands you need to use You can then use this chapter to learn more about the individual commands The commands in this chapter are described using the following format Command Header Command Description Syntax Statement shows the command format and Controls the multimeter s beeper When enabled the beeper emits a 1 kHz beep if an error occurs its parameters Parameters shown in brackets are optional have default values Parameters shown without The convo parameter choices are brackets have no default values Numeric and must be specifie
177. R SAMPLES 60Num_samples 1000 DESIGNATE NUMBER OF SAMPLES TOE int 2 0E 6 DESIGNATE EFFECTIVE INTERVAL 80ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 90ASSIGN Int_samp TO BUFFER Int_samp ASSIGN I O PATH NAME TO BUFFER 1OQ0OUTPUT Dvm PRESET FAST SSDC 10 SWEEP Eff int Num samples Chapter 5 Digitizing 01 FAST OPERATION TARM SYN SUB SAMPLING SINT OUTPUT FORMAT 10V RANGE 02 2us EFFECTIVE INTERVAL 1000 SAMPLES 10TRANSFER Dvm TO Int_samp WAIT SYN EVENT TRANSFER READINGS 200UTPUT Dvm ISCALE QUERY SCALE FACTOR FOR SINT FORMAT 30ENTER Dvm S ENTER SCALE FACTOR 400UTPUT Dvm SSPARM QUERY SUB SAMPLING PARAMETERS SOENTER Dvm N1 N2 N3 ENTER SUB SAMPLING PARAMETERS 60FOR I 1 TO Num_samples 70 Samp I Int_samp I CONVERT EACH INTEGER READING TO REAL NB FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE 80 R ABS Samp I USE ABSOLUTE VALUE TO CHECK FOR OVLD 90 IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE 200 Samp I Samp I S MULTIPLY READING TIMES SCALE FACTOR 210 Samp I DROUND Samp I 4 ROUND TO 4 DIGITS 220NEXT I 230Inc N1 N2 Inc TOTAL NUMBER OF BURSTS 240K 1 SORT SAMPLES 250FOR I 1 TO N1 j i 260 L I 1 270 FOR J 1 TO N3 280 Wave _form L Samp K l a 290 K K 1 5 300 L L Inc i 310 NEXT J i i 320NEXT I po 330FOR I N1 1 TO N1 N2 i 340 L I 350 FOR J 1 TO N3 1 1 360 Wave_form L Samp K 370 K K 1 i r 38
178. RE command for more information on the security code and how to secure or unsecure autocal Since the DCV autocal applies to all measurement functions you should perform it before performing the AC or OHMS autocal When ACAL ALL is specified the DCV autocal is performed prior to the other autocals The multimeter should be in a thermally stable environment with its power turned on for at least 2 hours before performing any autocal For maximum accuracy you should perform ACAL ALL once every 24 hours or when the multimeter s temperature changes by 1 C from when it was last externally calibrated or from the last autocal The AC autocal performs specific enhancements for ACV or ACDCV all measurement methods ACI or ACDCI DSAC DSDC SSAC SSDC FREQ and PER measurements The OHMS autocal performs specific enhancements for 2 or 4 wire ohms DCI and ACI measurements e Always disconnect any AC input signals before you perform an autocal If you leave an input signal connected to the multimeter it may adversely affect the autocal The autocal constants are stored in continuous memory they remain intact when power is removed You do not necessarily need to perform autocal simply because power has been cycled Chapter 6 Command Reference 157 ACBAND The time required to perform each autocal routine is ALL 11 minutes DCV 1 minute AC 1 minute OHMS 10 minutes e Related Commands CAL SCAL SEC
179. REAL DREAL or ASCII e Related Commands MATH MMATH SMATH 10 OUTPUT 722 TRIG HOLD SUSPENDS TRIGGERING 20 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 30 OUTPUT 722 NRDGS 10 TEN READINGS PER TRIGGER 40 OUTPUT 722 DCV 3 DC VOLTAGE 10V RANGE 50 OUTPUT 722 MATH STAT ENABLES STATISTICS MATH OPERATION 60 OUTPUT 722 TRIG SGL TRIGGERS THE MULTIMETER ONCE 70 OUTPUT 722 RMATH SDEV READS STANDARD DEVIATION 80 ENTER 722 A ENTERS STANDARD DEVIATION 90 PRINT A PRINTS STANDARD DEVIATION 100 END Recall Memory Reads and returns the value of a reading or group of readings stored in reading memory RMEM leaves stored readings intact not cleared from memory RMEM first count record first Designates the beginning reading Power on irst none Default first 1 count Designates the number of readings to be recalled starting with first Power on count none Default count 1 record Chapter 6 Command Reference 229 RQS RQS 230 Designates the record from which to recall readings Records correspond to the number of readings specified by the NRDGS command For example if NRDGS specifies three readings per trigger each record will contain three readings Power on record none Default record 1 Remarks The RMEM command automatically shuts off reading memory MEM OFF This means all previously stored readings remain intact and new readings are not s
180. REF Where Reading is any reading REF is the value in the REF register default 1 You can change the value in the REF register using the SMATH command Chapter 4 Making Measurements 10 20 30 40 50 60 70 80 10 20 30 40 50 60 70 80 85 90 100 10 20 30 40 50 OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 TRIG SYN OUTPUT 722 ACV AC VOLTAGE MEASUREMENTS AUTORANGE OUTPUT 722 SETACV ANA ANALOG ACV METHOD OUTPUT 722 SMATH REF 0 1 WRITE 0 1 TO REF REGISTER OUTPUT 722 MATH DB ENABLE REAL TIME DB OPERATION ENTER 722 A SYN EVENT ENTER DB PRINT A PRINT DB END For example if the input voltage is 0 1 V and the output voltage is 10V the gain is 20elogj9 10 0 1 20elog 100 40dB The following program is similar to the preceding program except that it uses the post process DB operation OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 TRIG SYN OUTPUT 722 ACV AC VOLTAGE MEASUREMENTS AUTORANGE OUTPUT 722 SETACV ANA ANALOG ACV METHOD OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE OUTPUT 722 SMATH REF 0 1 WRITE 0 1 TO REF REGISTER OUTPUT 722 MMATH DB ENABLE POST PROCESS DB OPERATION OUTPUT 7227 TRIG SGL TRIGGER READING ENTER 722 A RECALL READING USING IMPLIED READ PERFORM DB OPERATION PRINT A PRINT DB RESULT END DBM The DBM math operation calculates the power delivered to a resistance referenced to 1 mW The equation is Result 10celog 10 Re
181. Reading Rate Li Li Li Li Li Li Li Li 1 3 I 4 I 4 1 5 1 5 1 6 1 6 I 7 I 8 Turns on offset compensation I 8 End of dmm program memory SD DDDE A I Calls the dmm program 345 346 Appendix D Optimizing Throughout and Reading Rate Appendix E High Resolution Digitizing With the 3458A Introduction sesiis neevit iie 349 Speed with Resolution c ccceeseeseeseeeeteetteeees 349 Digitizing Analog Signals 0 esses 350 Avoiding Aliasing ccccecceesceteeseeeeteeeeeeees 350 Choice of Two Measurement Paths eee 351 Using the DCV Path for Direct Sampling 351 Using the Track and Hold Path for Direct or Sequential Sampling ccceeesesseesteeteeeteees 352 Capturing the Data ceeecesseesseeeseesteeseeeeees 352 High Speed Data Transfers ceeeseeeeeeeeeees 355 Software Help The Wave Form Analysis Library 355 Starter Main Program ccceesceseeeteeteeteees 357 Errors in Measurements 0 c esceeseceeeteeseeneeeees 358 Amplitude Errors cccesceeceeceseeseeeeceseeeeaeees 359 Trigger and Timebase Errors eeeeeeeeees 361 Appendix E High Resolution Digitizing With the 3458A 347 348 Appendix E High Resolution Digitizing With the 3458A Appendix E High Resolution Digitizing With the 3458A Introduction From Product Note 3458A 2 In your system or stand alone
182. S GROUP EXECUTE TRIGGER GET TRIGGER 722 SENDS GROUP EXECUTE TRIGGER GET TO THE DEVICE AT ADDRESS 22 Appendix B GPIB Commands 307 TRIGGER GET 308 Appendix B GPIB Commands Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches Introduction iectedescleden We EA I ieee 311 Tools Reg ired Sisccesessseszesdecdben aesecgacioeedtatercdee 311 Procede ooo ee eeecececcccccccsessscceenseceeesececessseeeeestseeeess 311 Covers Removal Procedure cceeceeees 312 Guard Pushrod Removal Procedure 314 Front Rear Pushrod Removal Procedure 314 Switch Cap Installation Procedure 4 316 Covers Installation Procedure c0ccccc 318 Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches 309 310 Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches Introduction Either or both the Front Rear Terminals and Guard Terminal switches can be locked out to prevent changing their settings To do this first remove all covers from the 3458 Then remove the pushrods from the Front Rear and Guard switches Next place switch covers over the holes where the pushrods previously protruded through The switch covers are in the Front Rear Terminal and Guard Switch Lockout kit Last reinstall the instrument covers WARNIN
183. SET 30 OUTPUT 722 MEM FIFO ENABLES READING MEMORY FIFO MODE 40 OUTPUT 722 OHM SELECTS 2 WIRE OHMS MEASUREMENTS 50 OUTPUT 722 NRDGS 5 SELECTS 5 READINGS PER TRIGGER 60 OUTPUT 722 TRIG SGL GENERATES A SINGLE TRIGGER 70 OUTPUT 722 PAUSE SUSPENDS PROGRAM EXECUTION 80 OUTPUT 722 ACV SELECTS AC VOLTAGE MEASUREMENTS 90 OUTPUT 722 NRDGS 10 SELECTS 10 READINGS PER TRIGGER 100 OUTPUT 722 TRIG SGL GENERATES A SINGLE TRIGGER 110 OUTPUT 722 SUBEND SIGNIFIES THE END OF THE SUBPROGRAM 120 END When you call the above subprogram the multimeter executes the subprogram line by line Lines 20 through 60 cause the multimeter to make five 2 wire ohms readings and place them in reading memory When line 70 is encountered subprogram execution ceases A subsequent CONT command or Group Execute Trigger resumes program execution Lines 80 through 100 then cause the multimeter to make 10 AC voltage readings and place them in reading memory Chapter 6 Command Reference 215 PER PER 216 Syntax When the subprogram is finished a total of 15 readings are in memory To call the above subprogram send OUTPUT 722 CALL OHMAC1 After the five 2 wire ohms readings are complete connect an AC voltage source to the multimeter Subprogram execution is resumed by sending the CONT command or by executing on the controller TRIGGER 7 Period Instructs the multimeter to measure the period of the input signal You can specify w
184. SUB ENTRY MODE until the SUBEND command is executed or the RESET key is pressed The SUBEND command does not appear in the front panel menu unless you are storing a subprogram e Ifa SCRATCH DELSUB a second SUB command or the GPIB Device Clear command occurs in a subprogram the multimeter does not store the command but does store the rest of the subprogram Subprogram execution will be aborted if the RESET command is encountered do not store RESET in a subprogram e You can not store a subprogram with less than 800 bytes of subprogram state memory remaining e Subprogram execution will be aborted if an error is detected or the GPIB Device Clear command is received The GPIB Device Clear command will also abort the process of storing a subprogram Chapter 6 Command Reference Examples SUB The only way to take readings within a subprogram is to use the TARM SGL or TRIG SGL command When either of these commands is encountered the multimeter will not execute the next command in the subprogram until all specified readings are taken This also means all configuration and other triggering commands must occur before the TARM SGL or TRIG SGL command Any other trigger arm or trigger events except TARM EXT see next Remark will be executed in a subprogram but the readings will not be initiated until the subprogram is complete Whenever the TARM EXT command is encountered in a subprogram the multimeter waits until an external tr
185. SUBEND command Control then reverts back to either the subprogram that called it nested subprograms or to the GPIB input buffer or front panel keyboard whichever executed the subprogram The RETURN command can also be used to end the subprogram For example if you want to have a conditional termination of the subprogram place RETURN within an IF THEN loop Chapter 7 BASIC Language for the 3458A 277 Nesting Subprograms in the subprogram The RETURN command returns control to the caller without executing the SUBEND command For example 10 OUTPUT 722 SUB DMM CONE 20 OUTPUT 722 DCV 8 0 00125 30 OUTPUT 722 TRIG SGL 40 OUTPUT 722 ENTER A 60 OUTPUT 722 IF A lt 5 06 THEN RETURN 70 OUTPUT 722 ELSE 80 OUTPUT 722 TRIG SGE 90 OUTPUT 722 ENDIF 100 OUTPUT 722 SUBEND pe ae 120 OUTPUT 722 CALL DMM CONE 130 END One subprogram may call a second nested subprogram for execution before the first subprogram finishes execution When the second subprogram executes the SUBEND command the first subprogram continues with the next command following the embedded CALL command The 3458A has two requirements for nesting subprograms First the subprogram called from within another subprogram must be stored in internal memory before the subprogram doing the calling is stored This is because the 3458A checks the syntax of each command as it stores the subprogram When it encounters an embedded CALL comma
186. SUREMENTS 10V RANGE 30 OUTPUT 722 TRIG LEVEL SELECT LEVEL TRIGGER EVENT 40 OUTPUT 722 SLOPE POS TRIGGER ON POSITIVE SLOPE OF SIGNAL 50 OUTPUT 722 LEVEL 50 AC TRIGGER AT 50 OF 10V RANGE 5V AC COUPLED 60 END Level Filter Enables or disables the level filter function When enabled the level filter function connects a single pole low pass filter circuit to the input of the level detection circuitry The low pass filter has a 3 dB point of 75 kHz and prevents high frequency components from causing false triggers 190 Chapter 6 Command Reference LFREQ Syntax Remarks Example Syntax LFREQ LFILTER control control The control parameter choices are Numeric control Query parameter Equiv Description OFF 0 Disables the level filter no filtering is done ON 1 Enables the level filter Power on control OFF Default control ON Level filtering can be used when level triggering for DC voltage direct and sub sampling The level filter can also be used to reduce sensitivity to noise for frequency and period measurements or when making AC or AC DC voltage measurements using the synchronous method SETACV SYNC command Query Command The LFILTER query command returns the present level filter mode Refer to Query Commands near the front of this chapter for more information Related Commands DCV DSAC DSDC FREQ LEVEL NRDGS PER SETACV SYNC SLOPE SSAC SSDC SSRC TRIG OUTPUT 72
187. Sec NPLC Aperture Digits Bits A Zero A Zero 2 z 10000 off On gt 1 000 0 0001 14us 4 5 16 100 000 4 130 Pi 0 0006 10 us 5 5 18 50 000 3 150 as 0 01 167s 6 5 21 5 300 930 3 v 01 167ms 6 5 21 592 245 1 16 6 ms 7 5 25 60 29 4 Le 10 0 166s 85 28 6 3 Aperture 05us ius Oys 100s Ims 10ms 100ms 1s 100 8 5 28 36 min 18 min NPLC oo 001 00 o1 1 W W 1000 85 28 36min 18 min No of Digits 41 2 51 2 6m 712 8112 4 i 3 Integration Time log scaie Maximum Input Temperature Coefficient Auto Zero off Rated Input Non Destructive For a stable environment 1 C add the HI to LO 1000 V pk 1200 V pk a following additional error for AZERO OFF LO to Guard 200Vpk 350 V pk Range Error Guard to Earth 500 Vpk 1000 V pk j 100 mV 10 V 5 pVv C 100 V 1000 V 500 uV C 2 Resistance Input Terminals Terminal Material Gold plated Tellurium Copper Input Leakage Current lt 20pA at 25 C For PRESET DELAY 0 DISP OFF OFORMAT DINT ARANGE OFF Aperture is selected independent of line frequency LFREQ These apertures are for 60 Hz NPLC values where 1 NPLC 1 LFREQ For 50 Hz and NPLC indicated aperture will increase by 1 2 and reading rates will decrease by 0 833 For OFORMAT SINT gt 10 Q LO to Guard with guard open gt 10 2 Q Guard to Earth Two wire and Four wire Ohms OHM and OHMF Functions Range Full Scale Maximum Current Test Open Maximum Maximum Temperature Coef
188. T LINE 40 R ABS Rdgs I USE ABSOLUTE VALUE TO CHECK FOR OVLD 50 IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE 60 Rdgs I Rdgs I S MULTIPLY READING TIMES SCALE FACTOR 70 Rdgs I DROUND Rdgs I 4 ROUND TO 4 DIGITS 80 NEXT I 90 END DINT Format The following program is similar to the preceding program except that it takes 50 readings and transfers them to the computer using the DINT format 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_readings I J K DECLARE VARIABLES 30 Num_readings 50 NUMBER OF READINGS 50 40 ALLOCATE REAL Rdgs 1 Num readings CREATE ARRAY FOR READINGS 50 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 60 ASSIGN dBuffer TO BUFFER 4 Num_readings ASSIGN BUFFER I O PATH NAME 70 OUTPUT Dvm PRESET NORM RANGE 10 OFORMAT DINT NRDGS Num_readings 75 TARM AUTO TRIG SYN DCV 10V RANGE DINT OUTPUT FORMAT NRDGS 50 AUTO 80 TRANSFER Dvm TO Buffer WAIT SYN EVENT TRANSFER READINGS 90 OUTPUT Dvm ISCALE QUERY SCALE FOR DINT 00 ENTER Dvm S ENTER SCALE FACTOR 10 FOR I 1 TO Num_readings 20 ENTER Buffer USING W W J K ENTER ONE 16 BIT 2 S COMPLEMENT 21 WORD INTO EACH VARIABLE J AND K STATEMENT TERMINATION NOT 25 REQUIRED W ENTER DATA AS 16 BIT 2 S COMPLEMENT INTEGER 30 Rdgs 1 J 65536 K 65536 K lt O CONVERT TO REAL NUMBER 40 R ABS Rdgs I USE ABSOLUTE VALUE TO CHECK FOR OVLD 50 IF R gt 2147483647 THEN PRINT OVLD IF
189. T PASSED BEFORE FAILURE WERE B PRINT PFAILNUM RESPONSE ELSE IF BIT 2 WAS NOT SET PRINT HI LOW LIMIT TEST PASSED PRINT TEST PASSED MESSAGE END IF END FILTER The filter math operation simulates the output of a single pole low pass RC filter This allows you to reduce the effects of random noise while preserving long term trends The equation is Result Previous Result x DEGREE 1 DEGREE Reading DEGREE Where Previous Result is initially set to the value of the first reading and thereafter is set to the result of this FILTER operation Reading is any reading DEGREE selects the step response of the filter The value of DEGREE corresponds to the step response of the low pass filter That is if 20 is the value of DEGREE 20 readings are required for the step response to achieve 63 of its final value You can achieve slower response or quieter readings by increasing the value of DEGREE The actual time constant RxC of the filter can be determined by om Sli 222 Fea 23 Fy jp DEGREE DEGREE 1 Where t the time constant RxC f the sampling rate which is I timer interval when using the TIMER and NRDGS commands or l effective interval when using the SWEEP command If you are not using the TIMER or SWEEP command refer to Determining the Reading Rate earlier in this chapter If DEGREE is larger than 10 RxC can be approximated by t I F x DEGREE Chapter 4 Making Measurem
190. TACV ANA ACI and ACDCI measurements you should specify resolution when you need more resolution than that provided by the NPLC command For example in the following program line 10 specifies 0 0001 PLC of integration time which selects 54 digits of resolution resulting in an actual resolution of 100 uV on the 10V range However for this application 10 uV of resolution is required with a max _input of 10V The preceding equation produces a resolution parameter of 0 0001 1E 4 which is specified in line 30 for this resolution a reading takes about 40 seconds 10 OUTPUT 722 NPLC 0001 20 OUTPUT 722 SETACV ANA 30 OUTPUT 722 ACV 10 1E 4 40 END For synchronous sampled ACV or ACDCV SETACV SYNC FREQ and PER measurements specifying resolution is the only way to change the actual resolution For these measurements the integration time is fixed and no interaction occurs between the NPLC command and the resolution parameter The multimeter achieves the specified resolution for sampled AC voltage by varying the number of samples taken If you default the _resolution parameter the multimeter sets the resolution to 0 01 Chapter 3 Configuring for Measurements 69 percent for the synchronous conversion method or 0 4 percent for the random conversion method The following program selects AC voltage measurements using the synchronous sampling conversion The maximum expected input voltage is 10 volts and a resolution p
191. TE FOR I 1 TO 37 ENTER 722 A I NEXT I Tns_time TIMEDATE Tns_time SUBEND SUB Program REAL Dnld_time Exe time Tns_time DIM A 37 Dnld_time TIMEDATE OUTPUT 722 PRESET MFORMAT SREAL OUTPUT 722 SUB 1 MEM FIFO OHM 1E4 NPLC 0 DELAY O0 NRDGS 15 TRIG SGL OUTPUT 722 OHM 1E5 NRDGS 8 TRIG SGL OUTPUT 722 OHMF 1E3 APER 20E 6 DELAY 1 NRDGS 2 TRIG SGL OUTPUT 722 ACV 250 ACBAND 250 DELAY 1 NRDGS 1 TRIG SGL O Oo O O D E O UTPUT 722 ACV10 ACBAND 25000 DELAY 01 TRIG SGL UTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 6 TRIG SGL UTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY 01 NRDGS 1 TR1G SGL UTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 3 TRIG SGL SUBEND nld_time TIMEDATE Dnld_time xe_time TIMEDATE UTPUT 722 CALL 1 Exe_time TIMEDATE Exe_time Tns_time TIMEDATE FOR I 1 TO 37 ENTER 722 A I NEXT I Tns_time TIMEDATE Tns_time SUBEND SUB Disp REAL Dnld_time Exe time Tns_time DIM A 37 Dnid_time TIMEDATE OUTPUT 722 PRESET MFORMAT SREAL DISP OFF TESTING OUTPUT 722 SUB 1 MEM FIFO OHM 1E4 NPLC 0 DELAY 0 NRDGS 15 TRIG SGL OUTPUT 722 OHM 1E5 NRDGS 8 TRIG SGL OUTPUT 722 OHMF 1E3 APER 20E 6 DELAY 1 NRDGS 2 TRIG SGL OUTPUT 722 ACV 250 ACBAND 250 DELAY 1 NRDGS 1 TRIG SGL Appendix D Optimizing Throughout and Reading Rate 2330 2340 2350 2360 2370 2380 2390 24 24 24 24 24 24 24 24 24 24 00 10 20 30 40 50 60 70 80 90 2500 2510 2520 2530 2540 2
192. UBEND Defeat REAL Dnld_time Exe time Tns_ time DIM A 37 Dnld_time TIMEDATE UTPUT 722 PRESET DISP OFF TESTING MFORMAT SREAL DEFEAT ON UTPUT 722 SUB 1 MEM FIFO OHM 1E4 NPLC 0 DELAY 0 NRDGS 15 TRIG SGL UTPUT 722 OHM 1E5 NRDGS 8 TRIG SGL UTPUT 722 OHMF 1E3 APER 20E 6 DELAY 1 NRDGS 2 TRIG SGL UTPUT 722 ACV 250 ACBAND 250 DELAY 1 NRDGS 1 TRIG SGL UTPUT 722 ACV 10 ACBAND 25000 DELAY 01 TRIG SGL UTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 6 TRIG SGL UTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY 01 NRDGS 1 TRIG SGL UTPUT 722 DCV10 NPLC 0 DELAY 0 NRDGS 3 TRIG SGL SUBEND 1ld_time TIMEDATE Dnld_time xe_time TIMEDATE UTPUT 722 CALL 1 Exe time TIMEDATE Exe time Tns_time TIMEDATE FOR I 1 TO 37 ENTER 722 A I NEXT I Tns_time T1IMEDATE Tns_time SUBEND 2 OomuUOCOOCOCOCO0C 0 MAIN PROGRAM COM A 20 B 90 C 30 D 30 J 80 CALL Test_58 Time58 END l l Appendix D Optimizing Throughout and Reading Rate 343 344 70 80 90 00 10 20 30 40 50 60 70 80 90 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 10 20 30 40 50 60 61 62 63 70 80 KB BB AB B B BR BR BWA 500 510 520 530 540 550 560 570 580 590 610 620 630 640 650 SUB Test_58 Time58 DIM A 20 B 90 C 30 D 30 J 80 SET UP SCANNER ASSIGN Scan TO 709 ASSIGN Dmm TO 722 CLEAR Dmm OUTPUT Dmm RESET Sets the dmm to po
193. URE Example ovureur 722 acan aLL 3458 RUNS ALL AUTOCALS USING FACTORY SECURITY CODE ACBAND AC bandwidth Specifies the frequency content bandwidth of the input signal for all AC or AC DC measurements Specifying the bandwidth allows the multimeter to configure for the fastest possible measurements Syntax ACBAND low _frequency high_frequency low_frequency Specifies the lowest expected frequency component of the input signal Power on low_frequency 20 Hz Default low_frequency 20 Hz high_frequency Specifies the highest expected frequency component of the input signal Power on high frequency 20 MHz Default high frequency 2 MHz Remarks Refer to the specifications in Appendix A for accuracy and reading rate specifications based on the bandwidth of the input signal For synchronous ACV or ACDCV SETACV SYNC command the bandwidth parameters are used by the multimeter to calculate time out values and sampling parameters When using level triggering default mode if the input signal is removed during a reading and does not return within the time limits the measurement method changes to random so that the reading can be completed After the reading the measurement method returns to SYNC For synchronous ACV or ACDCYV it is very important that the specified bandwidth corresponds to the frequency content of the signal being measured For frequency or period measurements with autorange enabled the bandwidth pa
194. URRED PRINT MESSAGE 60 Rdgs I Rdgs I S APPLY SCALE FACTOR 70 Rdgs I DROUND Rdgs I 8 ROUND CONVERTED READING 80 PRINT Rdgs I PRINT READINGS 90 NEXT I 200 END The LEVEL command specifies the level triggering voltage as a percentage of the present range and the coupling AC or DC for level triggering A level trigger event occurs when the input signal reaches the specified voltage on its positive going or negative going slope as specified by the SLOPE command LEVEL percentage coupling percentage Specifies the percentage of the present range for level triggering The valid range for this parameter is 500 to 500 in 5 steps for direct or sub sampling or 120 to 120 in 1 steps for DC voltage refer to Chapter 5 for details Power on percentage 0 0V Default percentage 0 OV The full scale values for direct sampling are 500 5 times the ranges of 10mV 100mV 1V 10V and 100V When specifying the level triggering percentage remember to use a percentage of the range For example assume the input signal has a peak value of 20V and you are using the 10V range If you want to level trigger at 15V you would specify a level triggering percentage of 150 LEVEL 150 command coupling The coupling parameter selects the coupling of the signal to the level detection Chapter 6 Command Reference 189 LFILTER LFILTER Remarks Example circuitry only This does not affect the coupling
195. UT and to stop automatically updating the display OUTPUT 722 DISP OFF TIME OUT MESSAGE TIME OUT In the following command the message must be enclosed in quotation marks because it contains a space OUTPUT 722 DISP MSG TIME OUT MESSAGE TIME OUT Direct Sampling Configures the multimeter for direct sampled measurements digitizing The DSAC function measures only the AC component of the input waveform The DSDC function measures the combined AC and DC components Otherwise the two functions are identical The DSAC and DSDC functions use the track hold circuit 2 nanosecond aperture and a wide bandwidth input path 12 MHz bandwidth DSAC max _input resolution DSDC max _input resolution Selects the measurement range You cannot use autorange for direct sampled measurements To select a range you specify max _input as the input signal s expected peak amplitude The multimeter then selects the correct range The 172 Chapter 6 Command Reference _resolution Remarks DSAC DSDC following table shows the max _input parameters and the ranges they select Full Scale max _put Selects SINT DINT Parameter Range Format Format T 0to 012 l0mV I2mV 50mV gt 012 to 120 100mV 120mV 500mV gt 120 to 1 2 1V 1 2V 5 0V gt 1 2 to 12 10V 12V 50V gt 12 to 120 100V 120V 500V gt 120 to 1E3 1000V 1050V 1050V Power on max _input not applicable Default max _input 10V Is ignored by the m
196. UTO DINT FORMATS 20OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 300UTPUT 722 MFORMAT SINT SINT READING MEMORY FORMAT 400UTPUT 722 SSDC 10 SUB SAMPLING 10V RANGE LEVEL SYNC SOURCE 45 EVENT DEFAULT EVENT SQOUTPUT 722 SWEEP 10E 9 4000 4000 SAMPLES 10ns EFFECTIVE INTERVAL 6Q0O0UTPUT 722 LEVEL 75 DC LEVEL TRIGGER AT 75 OF RANGE DC COUPLED 70OUTPUT 722 SLOPE POS LEVEL TRIGGER ON POSITIVE SLOPE 80OUTPUT 722 SSRC LEVEL LEVEL SYNC SOURCE EVENT Q9OOUTPUT 722 TARM SGL ENABLE SAMPLING 1LOOEND 142 Chapter 5 Digitizing Sub Sampling For sub sampling the trigger event and sample event requirements are Remarks ignored these events are discussed in Chapter 4 The only triggering events that apply to sub sampling are the trigger arm event TARM command and the sync source event SSRC command e Youcannot use the NRDGS command for sub sampling You must use the SWEEP command to specify the number of samples and the effective_interval The minimum effective_interval for sub sampling is 10 nanoseconds The maximum rate at which samples arc taken is 50k samples per second 20us between samples e You cannot use autorange for sub sampled measurements you must specify the range as the first parameter of the SSAC or SSDC command max input parameter The max input parameters and the ranges they select are max _ input Parameter Selects Range Full Scale 0 to 012 10mV 12mV gt
197. UTPUT 722 BEEP Notice the display s REM and LSTN annunciators are illuminated This means the multimeter is in the remote mode and has been addressed to listen receive a command The multimeter is capable of outputting readings and responses to query commands As an example have the multimeter generate a response to a query command by sending OUTPUT 722 ID When you send a query from remote the multimeter does not display the response as it did when you executed the command from its front panel Instead the multimeter sends the response to its output buffer The output buffer is a register that holds a query response or a single reading until it is read by the computer or replaced by new information Use the computer s input statement to get the response from the output buffer For example the following program reads the response HP 3458A and prints it 10 ENTER 722 AS 20 PRINT AS Chapter 2 Getting Started 43 The Local Key 44 Chapter 2 Getting Started 30 END The same technique allows you to get readings from the multimeter Whenever the multimeter is making measurements and you have not enabled reading memory reading memory is discussed in Chapter 4 you can get a reading by running the following program 10 20 30 ENTER 722 A PRINT A END When you press a key on the multimeter s keyboard while operating from remote the multimeter does not respond This is becau
198. V Figure 27 Level triggering 50 neg slope AC coupled The following program specifies level triggering to occur when the input signal reaches 5V 50 of the 10V range ona positive slope AC coupled Assuming the input signal has a peak value of 10V and the measurement range is 10V the result is shown in Figure 28 722 PRESET DIG DCV DIGITIZING 10V RANGE 722 TRIG LEVEL SELECT LEVEL TRIGGER EVENT 7227 SLOPE POS TRIGGER ON POSITIVE SLOPE OF SIGNAL 722 LEVEL 50 AC LEVEL TRIGGER AT 50 OF 10V RANGE AC COUPLED 10V OV DV 10V Figure 28 Level triggering 50 pos slope AC coupled In the following program the input signal is DC coupled to the level detection circuitry and consists ofa 5V peak AC signal riding on a 5V DC level In Chapter 5 Digitizing 133 LOOUTPUT 20O0UTPUT 300UTPUT 400UTPUT this case a negative percentage of the range 25 is used to level trigger at 2 5V positive slope Figure 29 shows the result 722 PRESET DIG DCV DIGITIZING 10V RANGE 722 TRIG LEVEL LEVEL TRIGGER EVENT 722 SLOPE POS TRIGGER ON POSITIVE SLOPE OF SIGNAL W227 LEVEL 25 DC LEVEL TRIGGER AT 25 OF 10V RANGE 45 DC coupled 50 END Level Filtering Note DCV Digitizing 134 Chapter 5 Digitizing OV 2 5V 5V 10V Figure 29 Level triggering 25 pos slope DC coupled When enabled the level filter function connects a single pole low pas
199. V gt 12 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to 1E3 1000V 1050V For ACV or ACDCV max _input Selects Full Parameter Range Scale l or AUTO Autorange 0 to 012 10mV 12mV gt 012 to 12 100mV 120mV gt 12 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to 1E3 1000V 1050V For OHM or OHMF max _input Selects Full Parameter Range Scale 1 or AUTO Autorange 0 to 12 10Q 120 gt 12 to 120 100Q 120kQ gt 120 to 1 2E3 1kQ 1 2kQ gt 1 2E3 to 1 2E4 10kQ 12kQ gt 1 2E4 1 2E5 100kQ 120kQ gt 1 2E5 to 1 2E6 IMQ 1 20MQ gt 1 2E6 to 1 2E7 10MQ 12MQ gt 1 2E7 1 2E8 100MQ 120MQ gt 1 2E8 1 2E9 1GQ 1 2GQ Power on max _input AUTO Default max _input AUTO 184 Chapter 6 Command Reference For DCI max _input Selects Full Parameter Range Scale 1 or AUTO Autorange 0 to 12E 6 pA 12uA gt 12E 6 to 1 2E 6 1pA 1 2pHA gt 1 2E 6 to 12E 6 10A 124A gt 12E 6 to 120E 6 1004A 120uA gt 120E 6 to 1 2E 3 ImA 1 2mA gt 1 2E 3 to 12E 3 10mA 12mA gt 12E 3 to 120E 3 100mA 120mA gt 120E 3 to 1 2 1A 1 05A For ACI or ACDCI max _input Selects Full Parameter Range Scale l or AUTO Autorange 0 to 120E 6 1004A 120uA gt 120E 6 to 1 2E 3 ImA 1 2mA gt 1 2E 3 to 12E 3 10mA 12mA gt 12E 3 to 120E 3 100mA 120mA gt 120E 3 to 1 2 1A 1 05A For DSAC or DSDC Full Scale max _input Selects SINT DINT Parameter Range format format 0 to 012 10mV 12mV 50mV gt 01
200. WAS NOT SET 190 PRINT HI LOW LIMIT TEST PASSED PRINT TEST PASSED MESSAGE 200 END IF 210 END The following program is similar to the preceding program except that it uses the post process PFAIL operation on 20 readings stored in memory The post process PFAIL operation is a batch operation That is the readings do not have to be recalled from memory in order to perform the PFAIL operation Also notice that the readings must be stored before enabling the post process PFAIL operation if not the MEMORY ERROR will occur Chapter 4 Making Measurements 123 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 165 170 180 190 200 124 OUTPUT OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO 722 MEM FIFO DCV 10 TRIG SYN ENABLE READING MEMORY FIFO MODE OUTPUT 722 SMATH MIN 9 LOWER LIMIT 9 V OUTPUT 722 SMATH MAX 11 UPPER LIMIT 11 V OUTPUT 722 CSB CLEAR STATUS REGISTER OUTPUT 722 RQS 2 ENABLE HI LO STATUS REGISTER BIT OUTPUT 722 NRDGS 20 20 READINGS TRIGGER OUTPUT 722 TRIG SGL TRIGGER READINGS OUTPUT 722 MMATH PFAIL PERFORM POST PROCESS PFAIL OPERATION OUTPUT 7227 STB QUERY SET BITS IN STATUS REGISTER ENTER 722 A ENTER QUERY RESPONSE IF BINAND A 2 THEN VIE Blt 2 0S SET PRINT Hi LOW LIMIT TEST FAILED PRINT FAILURE MESSAGE OUTPUT 722 RMATH PFAILNUM QUERY PFAILNUM REGISTER ENTER 722 B ENTER QUERY RESPONSE PRINT NUMBER OF READINGS THA
201. WEEP command occurs Refer to Triggering Measurements in Chapter 4 for an in depth discussion of the interaction of the various events for most measurement functions Refer to Chapter 5 for information on sub sampling Query Command The TRIG query command returns the specified trigger event Refer to Query Commands near the front of this chapter for more information Related Commands LEVEL LFILTER NRDGS SLOPE SWEEP T TARM TBUFF OUTPUT 722 TRIG AUTO SELECTS AUTO TRIGGER The following program shows a method to suspend measurements until the Chapter 6 Command Reference 257 TRIG multimeter is properly configured Line 20 suspends measurements by setting the trigger event to HOLD Lines 30 and 40 configure for 30 DC voltage readings per trigger event Line 50 generates a single trigger causing the multimeter to make thirty readings After the readings are complete the trigger event reverts to HOLD 10 OUTPUT 722 RESET RETURN TO POWER ON STATE 20 OUTPUT 722 TRIG HOLD SUSPEND READINGS 30 OUTPUT 722 DCV 10 DC VOLTAGE MEASUREMENTS 10V RANGE 40 OUTPUT 722 NRDGS 30 AUTO 30 READINGS PER SAMPLE EVENT AUTO 50 OUTPUT 722 TRIG SGL GENERATES A SINGLE TRIGGER 60 END 258 Chapter 6 Command Reference Chapter 7 BASIC Language for the 3458A Introduction scascuseaccancedetencessrsconveacervenntenneententaes 261 How It Works oi nainn iei ia oaa 261 BASIC Language Commands eeeeeeee
202. a controller on the bus you must use the ASCII output format The multimeter s TALK annunciator illuminates when in Talk Only mode You cannot specify address 31 with a controller on the bus To remove the multimeter from Talk Only mode press the Reset key or specify an address other than 31 The controller s address is typically 21 Do not use the controller s address for any other device on the GPIB bus e When the multimeter detects a CMOS RAM failure auxiliary error bit 12 It sets the address to 22 e ADDRESS Query From the multimeter s front panel you can read the present address using the Address key shifted Local key Related Commands ID Chapter 6 Command Reference 159 APER APER Syntax aperture Remarks Example Aperture Specifies the A D converter integration time in seconds APER aperture Specifies the A D converter s integration time and overrides any previously specified integration time or resolution The valid range for aperture is 0 1s in increments of 100ns Specifying a value lt 500ns selects minimum aperture which is 500ns Power on aperture is determined by the power on value for NPLC which specifies an integration time of 166 667ms for a 60Hz power line frequency or 200ms for a power line frequency of 50Hz or 400Hz Default aperture 500ns Since the APER and NPLC commands both set the integration time executing either will cancel the integration time previously e
203. acter _ or the question mark 2 Upper case is the same as lower case Variable names must not be the same as 3458A commands parameters or stored state names You can assign any numeric variable with the LET command the keyword LET is required For example the following statements are equivalent OUTPUT 722 LET TIME INT 120E 3 Chapter 7 BASIC Language for the 3458A 267 268 Variables for Data Storage Numeric Calculations Reading Multimeter Values Arrays OUTPUT 722 LET TIME INT 40 3E 3 Variables can replace numeric parameters in any 3458A command that uses numeric parameters Two examples uses are 1 numeric data storage and 2 numeric calculations The following sections discuss these two uses At power on numeric output data generated by the 3458A is placed into the GPIB output buffer where it can be sent to the system controller However for some applications you may want to store the output data directly into the multimeter s internal memory The ENTER command takes one reading out of reading memory destructively and places the value in the specified variable or array location The following program uses the ENTER command within a 3458A subroutine to store readings 10 OUTPUT 722 SUB DMM CONE 20 OUTPUT 722 NRDGS 100 30 OUTPUT 722 TRIG SGL 40 OUTPUT 722 INTEGER I 50 OUTPUT 722 FOR I 1 TO 100 60 OUTPUT 722 ENTER A I 70 OUTPUT 722 NEXT I 80 OUTPUT
204. acters or a combination of alpha and numeric characters the characters and_ can also be included in the name When using an alphanumeric name the first character must be alpha Alpha or alphanumeric subprogram names must not be the same as multimeter commands or parameters or the name of a stored state Following the SUB command enter the subprogram commands in the order you want them executed Use the SUBEND command to indicate the end of the subprogram All subprograms are stored in continuous memory remain intact when power is removed unless the subprogram is compressed see Compressing Subprograms later in this chapter For example the following program stores the commands in lines 20 through 60 as a subprogram entitled Chapter 3 Configuring for Measurements 71 DCCURI 10 OUTPUT 722 SUB DCCURIL 20 OUTPUT 722 MEM FIFO 30 OUTPUT 722 TRIG HOLD 40 OUTPUT 722 DCI 1 01 50 OUTPUT 722 NRDGS 5 AUTO 60 OUTPUT 722 TRIG SGL 70 OUTPUT 722 SUBEND 80 END If you create a new subprogram using the same name as an existing subprogram the new subprogram overwrites the old subprogram Executing a To execute a stored subprogram issue the CALL command along with the l 8 Subpro gram subprogram s name For example to execute the preceding subprogram send OUTPUT 722 CALL DCCUR1 Note When the input buffer discussed later in this chapter is off the multimeter does not release the GPIB until
205. ading RES 1 mW Where Reading is any voltage reading RES is the resistance value in the RES register default 50 You can change the value in the RES register using the SMATH command The following program uses the real time DBM operation to determine the input power to a loudspeaker Line 40 stores the speaker s impedance in the RES register for this example 8 Q The input voltage to the speaker is then measured and the DBM operation is performed OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 TRIG SYN OUTPUT 722 ACV AC VOLTAGE MEASUREMENTS AUTORANGE OUTPUT 722 SETACV ANA ANALOG ACV METHOD OUTPUT 722 SMATH RES 8 WRITE 8 TO RES REGISTER OUTPUT 722 MATH DBM ENABLE REAL TIME DBM OPERATION The following program uses the real time DB operation to determine an amplifier s voltage gain Line 40 stores the amplifier s input voltage 0 1 V in the REF register The amplifier s output voltage is measured and the gain of the amplifier is computed Chapter 4 Making Measurements 121 122 60 ENTER 722 A SYN EVENT ENTER DBM PRINT DBM For example if the input voltage is 10V the power is 10elog o 107 8 1 mW 40 97dBm The following program is similar to the preceding program except that it uses the post process DBM operation Ep RESET NRDGS 1 AUTO DCV 10 TRIG SYN AC VOLTAGE MEASUREMENTS AUTORANGE IA E IW 1E DT NALOG ACV METHOD NABLE READING MEMORY FIFO MODE RITE 8 TO RES REGIST
206. adings that passed PFAIL before a failure was encountered SELECTS THE POSITIVE GOING SLOPE FOR Power on Value 20 a EE E e E 1 E e a I 50 oo SO Default register DEGREE Power on register see above listing number Chapter 6 Command Reference 235 SRQ Remarks Examples The number parameter is the value to be placed in the register Default number last reading Power on number see above listing e You can use the SMATH command to place a number into one of the registers that store readings UPPER LOWER etc however that value will be replaced with a reading if the corresponding math function is enabled e g STATS e You cannot use 1 minus 1 to default the number parameter If you specify 1 you will actually write 1 to the register Related Commands MATH MMATH RMATH OUTPUT 722 SMATH 11 1E 3 PLACES 1E 3 IN THE SCALE REGISTER In the following program lines 10 and 20 configure for a resistance measurement Line 30 triggers the resistance measurement Line 40 defaults the number parameter causing the resistance reading to be stored in the RES register Line 50 instructs the operator to connect the voltage source to the multimeter Line 80 enables the DBM math operation This program displays the power delivered to the resistance in DB result of the DBM math operation 10 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN NRDGS 1 AUTO 20 OUTPUT 722 OHM SELECTS 2 WIRE OHMS
207. akes 10 readings per Readings trigger event one reading is taken per sample event and transfers them to the controller Notice that the input buffer is enabled line 40 This is because with the input buffer disabled the SGL event line 60 holds the GPIB bus until all specified readings are complete This would prevent line 70 from transferring all but the last reading to the controller Enabling the input buffer prevents the TRIG SGL command from holding the bus and allows each reading to be transferred as it becomes available 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 10 DIMENSION ARRAY FOR 10 READINGS 30 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 INBUF ON ENABLE INPUT BUFFER Chapter 4 Making Measurements 83 50 OUTPUT 722 NRDGS 10 AUTO 10 READINGS TRIGGER AUTO SAMPLE EVENT 60 OUTPUT 722 TRIG SGL TRIGGER READINGS 70 ENTER 722 Rdgs ENTER READINGS 80 PRINT Rdgs DISPLAY READINGS 90 END Multi ple Trigger The second parameter of the TARM command allows you to specify multiple Armin g trigger arming When multiple trigger arming is specified a single occurrence of the trigger arm event arms the multimeter the specified number of times The trigger arm event must be SGL for multiple arming This causes the multimeter to make multiple groups ofreadings as shown in Figure Iz ALL SPECIFIED READINGS TAKEN TRIGGER EVENT
208. al connections for frequency or period measurements from a current source are shown in Figure 11 Note The LEVEL command affects the zero crossing threshold and the input signal coupling for frequency and period measurements Refer to the 1 The leftmost digit which is a 4 digit for most measurement functions is a full digit 0 9 for frequency and period measurements Chapter 3 Configuring for Measurements 65 LEVEL command in Chapter 6 for more information Table 17 FSOURCE Parameters FSOURCE Definition Measurement Capabilities Parameter Frequency Period ACV AC coupled AC voltage input 1Hz 10MHz 100ns 1s ACDCV DC coupled AC voltage input 1Hz 10MHz 100ns 1s ACI AC coupled AC current input 1Hz 100kHz 10us 1s ACDCI DC coupled AC current input 1Hz 100kHz 10us 1s Note Specifying Bandwidth Note The following program configures the multimeter for frequency measurements on the 10V range from a voltage Source The input signal is AC coupled 10 OUTPUT 722 FREQ 10 20 OUTPUT 722 FSOURCE ACV 30 END The following program configures the multimeter for period measurements on the 10mA range from a current source The input signal is DC coupled 10 OUTPUT 722 PER 10E 3 20 OUTPUT 722 FSOURCE ACDCI 30 END You can reduce high frequency noise above 75kHz for frequency or period measurements by enabling the level
209. amples readings This chapter discusses the various ways to digitize signals the importance of the sampling rate and how to use level triggering Chapter 6 Command Reference This chapter discusses the multimeter s language HPML and contains detailed descriptions of each command in the language Commands are listed in alphabetical order Chapter 7 BASIC Programming Language This chapter describes the BASIC commands supported by the 3458A s internal BASIC language operating system With this feature many of your special requirements can be easily satisfied by writing and downloading a simple BASIC subprogram to customize the multimeter s behavior Appendices The appendices contain the multimeter s specifications information on the GPIB commands recognized by the multimeter information on locking out the front rear terminals switch and contains product notes concerning digitizing and maximizing the multimeter s reading rate and throughput Chapter 1 Installation and Maintenance Introduction oe eeceeceeecescceseeecececeeeeeeeeeecneeeeeeneeeees 15 Initial Inspection 0 eeeeceeseeseeeeceeeeeeeeeeeecneeeeeeeees 15 Options and Accessories c cceseceseeeteeeteesteesseens 16 Installing the Multimeter 0 0 eceeeeeeseereeeeeeees 17 Grounding Requirements c cccceseereeerees 1 Line Power Requirements ccccsceseeeteeetees 1 Setting the Line Voltage Switches 18 Installing the Line Power Fuse
210. and for sub sampling In sub sampling the multimeter will use as many periods of the input signal as necessary to achieve the specified effective_interval The minimum effective_interval for sub sampling is 10 nanoseconds Refer to Sub Sampling in Chapter 5 for a detailed description of the process Related Commands DSAC DSDC FUNC ISCALE LEVEL LFILTER MEM FIFO SLOPE PRESET FAST PRESET DIG SSDC SSPARM SSRC SWEEP TARM Examples In the following program the sub sampled data is sent to reading memory using th in e required SINT memory format The multimeter places the samples in memory the corrected order The samples are then transferred to the controller using the DREAL output format when placing sub sampled data in reading memory first you are not restricted to using the SINT output format 10 20 30 40 50 60 70 80 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 REAL Samp 1 200 BUFFER CREATE BUFFER ARRAY ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS ASSIGN Samp TO BUFFER Samp ASSIGN BUFFER OUTPUT Dvm PRESET FAST TARM SYN TRIG AUTO DINT FORMATS OUTPUT Dvm MEM FIFO FIRST IN FIRST OUT READING MEMORY OUTPUT Dvm MFORMAT SINT SINT MEMORY FORMAT OUTPUT Dvm OFORMAT DREAL DOUBLE REAL OUTPUT FORMAT Chapter 6 Command Reference 90 00 10 20 30 40 50 60 70 80 90 200 SSAC SSDC OUTPUT Dvm SSDC 10 SUB SAMPLING 10V RANGE DC COUPLED OUTPUT D
211. and Double The single integer SINT format has 2 bytes per reading and the double 8 Integer integer DINT format has 4 bytes per reading Both formats use two s complement coding Note When using the SINT or DINT memory output format the multimeter applies a scale factor to the readings The scale factor is based on the multimeter s measurements function range A D converter setup and enabled math operations You should not use the SINT or DINT format for frequency or period measurements when a real time or post process math operation is enabled except STAT or PFAIL or when autorange is enabled Two s Complement Two s complement binary coding is a method that allows a binary number Binary Coding to represent both positive and negative integers Two s complement coding is done by changing the sign and in effect the decimal equivalent of the most significant bit MSB When the MSB is set 1 in a 1 byte two s complement number its value is 1 x 2 128 When the MSB is reset 0 its value is 0 x 27 0 Note that the range ofan 8 bit 1 byte two s complement number is 128 to 127 not 0 to 255 The following example resolves the decimal equivalent of this two s complement word 10110101 10010110 This two s complement word is equivalent to 2 5 213 212 210 4 98 4 274244 2742 Which evaluates to 19050 92 Chapter 4 Making Measurements Single Real SREAL Example The single real SREA
212. ander doit orca te 338 Appendix D Optimizing Throughout and Reading Rate 319 320 Appendix D Optimizing Throughout and Reading Rate Appendix D Optimizing Throughout and Reading Rate Introducing the Application Oriented Command Language Intrinsically Slow Measurements From Product Note 3458A 1 In the past decade and a half microcomputers have greatly improved both their internal speed and their speed of communication with other equipment The actual clock rates of microcomputers used in instrumentation has gone from under 1 MHz to over 12 MHz and the data bus has gone from 8 bits to 16 bits During this same time period the system multimeter has undergone an even more remarkable evolution in terms of both its speed of operation and its reading rate In 1975 24 readings per second with 5 1 2 digits of resolution was considered very fast today the 3458A Multimeter can make 50 000 readings per second with 5 1 2 digits two thousand times faster This extraordinary increase in speed is attributable not simply to faster microcomputers but to advances in the analog to digital conversion process a better utilization of the microcomputer and a better understanding of the application needs of the system user 3458A The 3458A Multimeter now has reading rates from 4 1 2 digit DC Volts measurements at 100 000 per second to 8 1 2 digit DC Volts measurements at 6 per second or anywhere in between with a trade off of l
213. arameter of 1 selects 5 5 digits resulting in an actual resolution of mV 10 OUTPUT 722 SETACV SYNC 20 OUTPUT 722 ACV 10 1 30 END Configuring for Ratio Measurements For ratio measurements the multimeter measures a DC reference voltage applied to the Q Sense terminals and a signal voltage applied to the Input terminals The multimeter then computes the ratio as Signal Voltage oe DC Reference Volta The signal voltage measurement function can be DC voltage AC voltage or AC DC voltage For AC or AC DC voltage any of the three measurement methods ANA RNDM or SYNC may be used The reference voltage measurement function is always DC voltage and has a maximum measurable input of 12VDC Figure 15 shows the front connections for ratio measurements Note The Q Sense LO and the Input LO terminals must have a common reference and cannot have a voltage difference greater than 0 25V FOR GUARDED MEASUREMENTS ONLY Figure 15 Ratio measurement connections 70 Chapter 3 Configuring for Measurements Specifying Ratio Measurements To specify ratio measurements you first select the measurement function for the signal measurement and the measurement method for AC or AC DC voltage and then enable ratio measurements using the RATIO command For example the following program specifies AC voltage ratio measurements on the 10V range using the synchronous sampling conversion 10 OUTPUT 722 A
214. arity is the largest step that occurs between successive quantization levels Integral non linearity is the maximum deviation of the linearity curve from a leastmean square fit In general differential non linearity may cause significant measurement error if a low level signal happens to fall on that part of the ADC transfer function with the differential non linearity error Integral non linearity in an ADC is generally more detrimental when digitizing full scale signals Realize that the transfer function for an ADC is very dependent upon the slew rate dV dt The transfer function for a static DC input level may appear close to the ideal The transfer function under dynamic operating conditions may exhibit numerous errors as shown in Figure 61 Appendix E High Resolution Digitizing With the 3458A 359 An inescapable reality in any measurement is the attendant noise with increasing bandwidth The effects of random measurement noise can be reduced by averaging the measurements Caused by Johnson noise and other circuit related noise as well as noise on the input signal the removal of this noise always costs measurement time A measure of the quality of a digitizing instrument called the effective bits of resolution combines noise with ADC linearity to show the usable resolution of the digitizer effective bits N log rms error actual rms error ideal Figure 61 With static DC input levels the analog to digital converter m
215. ars the status register Line 40 instructs the controller to go to line 90 should an interrupt occur Line 50 enables SRQ interrupts on the GPIB interface Line 60 enables the hi lo limit power on and error bits to assert SRQ Line 60 also enables the real time pass fail math operation with the values of 5 for the low limit and 5 for the hi limit Line 70 enables automatic triggering Line 80 causes the controller to wait for an interrupt Lines 90 through 130 read the status register and print which condition s caused the interrupt 78 Chapter 3 Configuring for Measurements Chapter 4 Making Measurements Jptrod ction 3 ss iscenceascenceksdcscevandepnnea ceveeaaconnensdertene e 81 Triggering Measurement cceseseeeceeeeeeeeeees 81 The Trigger Arm Event seess 82 The Trigger Event ccccccsccsseceseeeeeeeesteeneees 82 The Sample Event ccccccccsceseceteceteeeeeenees 82 Everitt Choice Sne des cence 82 Making Continuous Readings ceeeeee 82 Making Single Readings eeceseseeeeteeeee 83 Making Multiple Readings ceceeeseeseeeeees 83 Multiple Trigger Arming s es 84 Making Synchronous Readings eeeeee 84 Making Timed Readings 1 0 0 ceeceseeeeeeteeeee 85 Making Delayed Readings eeeeeeseereeeee 86 Default Delays cccceeccsscseseeseeseeteeeteeees 87 External Triggering 0 ccceceescceseeseeeteetteeneees 87 External Trigger Buffering 0 0 e
216. ast ACAL of Reading of Range C For DELAY 1 ARANGE OFF For DELAY 0 NPLC 1 unspecified reading rates of greater than 500 sec are possible Appendix A Specifications 293 Settling Characteristics For first reading or range change error using default delays add 01 of input step additional error for the 100 uA to 100 mA ranges For the 1 A range add 05 of input step additional error The following data applies for DELAY 0 Function ACBAND Low DC Component Settling Time ACI 210 Hz DC lt 10 AC 0 5 sec to 0 01 DC gt 10 AC 0 9 sec to 0 01 ACDCI 10 Hz 1 kHz 0 5 sec to 0 01 1 kHz 10 kHz 0 08 sec to 0 01 210 kHz 0 015 sec to 0 01 Maximum Input Rated Input Non Destructive ItoLO 1 5 A pk lt 1 25A rms LO to Guard 200 V pk 350 V pk Guard to Earth 500 V pk 1000 V pk 6 Frequency Period Frequency Period Characteristics Voltage AC or DC Coupled Current AC or DC Coupled The source of frequency measurements and the ACV or ACDCV Functions ACI or ACDCI Functions measurement input Frequency Range 1 Hz 10 MHz 1 Hz 100 kHz coupling are determined by Period Range 1 sec 100 ns lsec 10 us the FSOURCE command Input Signal Range 700 V rms 1 mV rms 1 A rms 10 uA rms Range dependent see ACI Input Impedance 1 MQ 15 with lt 140 pF 0 1 730 Q2 for ieee impedance values Time is d ined Accuracy Reading Rates ae ce as 24 Hour 2 Y
217. at which is 2 bytes per sample the GPIB controller must be able to handle the data at a maximum rate of 100k bytes per second If not the multimeter generates the TRIGGER TOO FAST error In the program on the following page the SSAC command is used to digitize a 10 kHz signal with a peak value of 5V The SWEEP command instructs 1O0OPTION BASE 20INTEGER Num samples Inc I J K L 30Num_samples 1000 40Eff_int 2 0E 6 the multimeter to take 1000 samples Num_samples variable with a 2us effective_interval Eff_int variable The measurement uses the default level triggering for the sync source event trigger from input signal 0 AC coupling positive slope Line 110 generates a SYN event and transfers the samples directly to the computer Lines 230 through 400 sort the sub sampled data to produce the composite waveform The composite waveform is stored in the Wave_form array COMPUTER ARRAY NUMBERING STARTS AT 1 DECLARE VARIABLES DESIGNATE NUMBER OF SAMPLES DESIGNATE EFFECTIVE INTERVAL SOINTEGER Int_samp 1 1000 BUFFER CREATE INTEGER BUFFER 60ALLOCATE REAL Wave _form 1 Num_samples CREATE ARRAY FOR SORTED DATA 7OALLOCATE REAL Samp l Num_samples CREATE ARRAY FOR SAMPLES 8OASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 9O0ASSIGN Int_samp TO BUFFER Int_samp OQOOUTPUT Dvm PRESET FAST LEVEL SLOPE SSDC 10 SWEEP Eff int Num_samples FAST OPERATION TARM SYN DEFAULT LEVEL amp SLOPE OS OUTPUT FORMAT 10V RANGE 2us EFFECT
218. ay exhibit an ideal transfer function as shown in 12a With a dynamic input however errors shown in 12b may ae appear Threshold Level Band Edge Output Codes H Quantization Step Or Band TESE E E integral Nonlinearity bey Y 1 2 LSB T 4 Missing Codes ae Output Codes p44 f X Differential Nonlinearity X 1 LSB Input Voltage b Dynamic Input Conditions The rms error actual is the error measured relative to the best fit perfect sine wave The rms error ideal is the theoretical error from a perfect N bit ADC For low resolution instruments the effective bits is a true measure quality for high resolution instruments the noise associated with any measurement swamps the actual performance of the ADC If however a large number of samples is taken or equivalently the samples are averaged the noise can be reduced to the point where actual quantization and non linearity errors are evident in the Fourier transform of the sampled data This effect is shown in Figure 62 The third harmonic of the input signal is actually an integral non linearity Averaging ten samples does not remove its level whereas the noise floor drops 10 dB 360 Appendix E High Resolution Digitizing With the 3458A Trigger and Timebase Errors Figure 62 Analog to dig ital converters that exhibit non linearity errors cause spurious responses that averaging will not rem
219. been impaired either through physical damage excessive moisture or any other reason REMOVE POWER and do not use the product until safe operation can be verified by service trained personnel If necessary return the product to Keysight for service and repair to ensure that safety features are maintained DO NOT service or adjust alone Do not attempt internal service or adjustment unless another person capable of rendering first aid and resuscitation is present DO NOT substitute parts or modify equipment Because of the danger of introducing additional hazards do not install substitute parts or perform any unauthorized modification to the product Return the product to Keysight for service and repair to ensure that safety features are maintained Measuring high voltages is always hazardous ALL multimeter input terminals both front and rear must be considered hazardous whenever inputs greater than 42V dc or peak are connected to ANY input terminal Permanent wiring of hazardous voltage or sources capable of delivering grater than 150 VA should be labeled fused or in some other way protected against accidental bridging or equipment failure DO NOT leave measurement terminals energized when not in use DO NOT use the front rear switch to multiplex hazardous signals between the front and rear terminals of the multimeter 7 Agilent Technologies DECLARATION OF CONFORMITY C According to ISO IEC Guide 22 and CEN CENELEC
220. benchmarks with properly structured programs for maximum throughput using pass fail limit checking and statistics DC Volts DC Current and Resistance The 3458A offers two separate measurement paths the standard DCV path direct to the Analog to Digital Converter and a path to the track and hold circuit track and hold path The DCV path is limited to 150 kHz bandwidth the Appendix D Optimizing Throughout and Reading Rate 323 Through the DCV 324 Optimizing Path track and hold path can accept signals up to 12 MHz The track and hold path is limited to 16 bits of resolution unless repeated measurements are made The DCV path can present up to 8 1 2 digits 27 bits resolution The classic trade offs one can make with the 3458A are measurement speed versus measurement resolution Because of early design decisions to reduce the intrinsic Johnson noise associated with real resistive components in the input path of the 3458A the resolution of the integrated measurement is 3 times better than with dmms of previous generations For example with the 3457A one may make a 6 1 2 digit 3 000 000 count measurement with one power line cycle of integration PLC or 17 ms with the equivalent integration period the 3458A may make a 7 1 2 digit measurement 12 000 000 counts Similarly extreme care is taken to insure the linearity is excellent a factor of 10 times better than the 3457A The result is faster more accurate measurements than eve
221. ble Default _resolution 00001 The reading rate is the longer of 1 period of the input signal the gate time or the default reading time out of 1 2 seconds e Period and frequency measurements are made using the level detection circuitry to determine when the input signal crosses a particular voltage on its positive or negative slope This is why you cannot use the LEVEL trigger or sample event or the LINE trigger event when making period or frequency measurements The power on or default level triggering values select zero volts positive slope You can control the level triggering voltage and coupling using the LEVEL command You can specify either the positive or negative slope using the SLOPE command The leftmost digit which is a half digit for most measurement functions is a full digit 0 9 for period measurements Readings made with autorange enabled take longer because the input signal is sampled to determine the proper range between readings e For period and frequency measurements an overload indication means the voltage or current amplitude is too great for the specified measurement range It does not mean the applied period or frequency is too great to be measured e Related Commands ACBAND FREQ FSOURCE FUNC RES 10 OUTPUT 722 FSOURCE ACI SELECTS AC CURRENT AS INPUT SOURCE 20 OUTPUT 7229 PER 01 SELECTS PERIOD MEASUREMENTS 10mA RANGE 30 END Configures the multimeter to one of three predef
222. bprogram name which already exists in 3458A memory the new subprogram overwrites the previous subprogram Subprogram Command Types Definition Deletion Commands SUB SUBEND DELSUB The 3458A s subprogram related commands are used only within subprograms Subprogram definition and deletion commands deal with the storage viewing and deletion of subprograms from internal memory Execution commands control execution of subprograms from inside or outside a subprogram Subprogram definition and deletion commands identify the beginning and end of subprograms store and delete subprograms from memory and list the subprograms presently stored in internal memory The syntax statements for the subprogram definition and deletion commands are shown below SUB sub_name SUBEND DELSUB sub_name SCRATCH CAT LIST sub_name COMPRESS sub_name Every 3458A subprogram must contain a SUB and SUBEND command The SUB command must be the first line in all 3458A subprograms It identifies where the subprogram begins and assigns the name to the subprogram When the SUB command is executed the 3458A begins storing the subprogram in internal memory The SUBEND command must be the last line in all 3458A subprograms It identifies where the subprogram ends and also terminates the entry of the subprogram Commands listed between the SUB and SUBEND commands are executed in order every time the subprogram is executed Only one SUB and one SUBEND com
223. byte 3 11001000 01001000 10010000 200 72 144 mantissa 200 x 27 72 x 2 15 144 x 2 23 1 56471443177 or mantissa 200 x 216 72 x 28 144 x 2 73 1 56471443177 Chapter 4 Making Measurements 93 Double Real The SREAL number is then calculated by 1 x 2 x 156471443177 6 1121657491E 3 The double real DREAL format conforms to IEEE 754 specifiations and contains 64 bits 8 bytes per reading as follows byte 0 byte 1 byte 2 byte 3 S EEE EEEE EEEE MMMM MMMM MMMM MMMM MMMM byte 4 byte 5 byte 6 byte 7 MMMM MMMM MMMM MMMM MMMM MMMM MMMM MMMM Where S sign bit 1 negative 0 positive E base two exponent biased by 1023 to decode these 11 bits subtract 1023 from their decimal equivalent M mantissa bits those right of the radix point There is an implied most significant bit MSB to the left of the radix point This bit is always 1 This provides an effective precision of 53 bits with the least significant bit right most weighted 2 2 Another way to evaluate this mantissa is to convert these 53 bits MSB 1 to an integer and then multiply by 2 The value of a number in the DREAL format is calculated by 1 8 x mantissa x p exponent Using Reading Memory 94 The multimeter stores readings in memory whenever readings are being taken and reading memory is enabled Reading memory has a FIFO first in first out mode and a LIFO last in first out mode In the FIFO mode the first r
224. called the power on state Chapter 2 Getting Started 25 The Display 26 Chapter 2 Getting Started Table 5 Power On State Command Description ACBAND 20 2E6 AC bandwidth 20Hz 2MHz AZERO ON Autozero enabled DCV AUTO DC voltage autorange DEFEAT OFF Defeat disabled DELAY 1 Default delay DISP ON Display Enabled EMASK 32767 Enable all error conditions END OFF Disable GPIB EOI function EXTOUT ICOMP NEG Input complete EXTOUT signal negative pulse FIXEDZ OFF Disable fixed input resistance FSOURCE ACV Frequency and period source is AC voltage INBUF OFF Disable input buffer LEVEL 0 AC Level trigger at 0 AC coupled LFILTER OFF Level filter disabled LFREQ 50 or 60 Measured line frequency rounded to 50 or 60Hz LOCK OFF Keyboard enabled MATH OFF Disable real time math MEM OFF Disable reading memory last memory operation FIFO MFORMAT SREAL Single real reading memory format MMATH OFF Disable post process math NDIG 7 Display 7 5 digits NPLC 10 10 power line cycles of integration time NRDGS 1 AUTO 1 reading per trigger auto sample event OCOMP OFF Disable offset compensated resistance OFORMAT ASCII ASCII output format QFORMAT NORM Normal query format RATIO OFF Disable ratio measurements RQS 0 or 8 0 disables status register conditions if power on SRQ was on when power was removed value 8 SETACV ANA Analog AC voltage mode SLOPE POS Positive s
225. ccccccstscecseetsessesssecesesecceesssetesanecs 328 Synchronous ACV ccccccesseeeteeereeetetteessees 328 Random ACV mesite 328 Comparison of ACV Modes cscceseeeeee 329 AC CUnrenit opienie i a siaen ine 329 Frequency and Period ccecceeeeseeeeeteeeees 330 Optimizing the Testing Process Through Task AMO CA ON iesti eRe leans 330 Math Operations ccccccceeseeessesecseeseenteesees 330 Data Storage ccciiccediescevescccensesssatedesaesdieeenes 330 Output Formats 200 cccccceeceseeeseeeeteeeeeeeeeees 331 State Storage and Program Memory 331 Measurement List 0 0 cceeceeceeseeseeeeeeeeereeeeenee 332 A Benchmark sci isscsdssseiienceveavseansdad aed degeviedeness 333 Benchmark Results cececeseseeeeeeeeeeneeees 334 Still FASter seessvcassiccsssssteescanceressscestestseveesseaveeacs 338 Appendix E High Resolution Digitizing With the 3458A TtOGUCHIOM 3 i2ccisesceiidecs vlantkddencea eitanedeeegesdeeuaneate 349 Speed with Resolution ccecccsceeseeseceteeereeeees 349 Digitizing Analog Signals 0 0 0 eeeeeeeeees 350 Avoiding Aliasing 00 ccceeceeeseeseeseeseeeseees 350 Choice of Two Measurement Paths 08 351 Using the DCV Path for Direct Sampling 351 Using the Track and Hold Path for Direct or Sequential Sampling ce eeseeseetesteesees 352 10 Contents Capturing the Data ccceccesseeseeeeeesteesteeteeees 352 Errors in Measurements cccc
226. cccsssesceesteeseeeeeeees 358 High Speed Data Transfers 2 0 0 0 cceeeseeseeeeees 355 Amplitude Errors eccescceccsceeseeceeeeceeeseeneees 359 Software Help The Wave Form Analysis Library 355 Trigger and Timebase Errors ceeeeeees 361 Starter Main Program ccceeseeseeereeeteeseees 357 Contents 11 12 Contents Chapter 1 Installation and Maintenance Jntrod ction peccasceucsaccenceksacs covandevnaed dovbeaacentensdeveenaas 15 Initial Inspections rnesa a 15 Options and Accessories cscceseceseeeteeeteesteesteens 16 Installing the Multimeter 0 0 cee eeeeeereeeeeeeeeees 17 Grounding Requirements c cccceseeeseeetees 17 Line Power Requirements e eceeceeseeeeeeees 17 Setting the Line Voltage Switches 18 Installing the Line Power Fuse eseeeeee 18 POWEE Cords nanesen teie ianinan 18 Connecting the GPIB Cable 0 0 eee eeeenees 19 The GPIB Address cceccecseeceeseeceeeeeeeeeeaeees 20 Mounting the Multimeter eeeeeeeeeeeeeeeee 20 Installation Verification ccceeeeceeseeeeteeeee 21 Maintenance sociccesccascvncektentcetseeecebactecnhaceecneuatereease 21 Replacing the Line Power Fuse eseee 21 Replacing a Current Fuse ceeeseeeeeeteeeee 21 Repair Service poine ai 22 Serial Number ou eceeeeeceseeseeeeceeeeeeeeeees 22 Shipping Instructions 0 eceeeeeeseereeeeeeee 22 Chapter 1 Installation and Maintenance
227. ccsnte thar iiare erei aiai 61 Offset Compensation cccccceeseesseesteeteeeteeees 62 Fixed Input Resistance cceccceseeeseeteeeeeeees 62 Configuring for AC Measurements eseee 62 AC or AC DC Voltage cccccccccscceteesreeteeeees 62 Synchronous Sampling Conversion 63 Analog RMS Conversion cccessesseeeteees 64 Random Sampling Conversion 06 64 Specifying the AC Voltage Method 64 AC or AC DC Current ooo eeceeeeereeereeenes 64 Frequency or Period ccccesccceseeeeeseetteeseees 65 Specifying Bandwidth 0 0 cecceeeseeseereeeees 66 Setting the Integration Time 0 00 00 eeeeeeeeeeees 67 Specifying Resolution ccccceeeesseeeseetteeeeees 68 When to Specify Resolution cece 69 Configuring for Ratio Measurements 0 70 Specifying Ratio Measurements eeee 71 Using Subprogram Memory ccccecsesseeseeteeeees 71 Storing a Subprogram ccccccesseesseeeteesteeeeees 71 Executing a Subprogram c ceecccseeeseesteenees T2 Suspending Subprogram Execution 0 72 Nested Subprograms c ccecsesseeseeeteeteeesees 73 Autostart Subprogram cccccseeseeeteeeeeeneeees 73 Compressing Subprograms ccccseeeerees 73 Deleting Subprograms ccccecceeseeteesteeetees 74 Using State Memory ou eececcecetecesceeeeeeseeseenseees 74 Storing States nennir nonna eaan 74 Recalling States
228. ces a _ resolution parameter of 0 000001 1E 6 This is specified in line 20 10 OUTPUT 722 NPLC 1 20 OUTPUT 722 DCV 10 1E 6 30 END The autozero function ensures that any offset errors internal to the multimeter are nulled from subsequent DC or ohms measurements The autozero function is controlled using the AZERO command With AZERO ON the multimeter internally disconnects the input signal and makes a zero reading following every measurement It then algebraically subtracts the zero reading from the preceding measurement With AZERO OFF or ONCE the multimeter takes one zero reading and algebraically subtracts this from subsequent readings After you execute AZERO OFF or AZERO ONCE the multimeter takes the autozero measurement when the first trigger arm event occurs for all events except TARM EXT which causes an autozero measurement when the TARM EXT command is executed The trigger arm event is discussed in Chapter 4 The autozero measurement is updated whenever the measurement function range or integration time is changed this update is made when the trigger arm event occurs or TARM EXT is executed In the power on PRESET NORM state AZERO is set to ON You can change it by sending OUTPUT 722 AZERO OFF You should leave autozero on AZERO ON command for 4 wire ohms measurements If you must disable autozero AZERO OFF or ONCE be sure to make all measurement connections before disabling autozero and ensure tha
229. cified subprogram Keep in mind that you cannot edit subprograms from the front panel you must edit them from your system controller The following program shows how to list the subprogram DMM_COMF to your system controller 10 DIM AS 100 20 OUTPUT 722 LIST DMM CONE 30 REPEAT 40 ENTER 722 A 50 PRINT A 60 UNTIL AS SUBEND 70 END The COMPRESS command removes the text of the specified subprogram from internal memory the subprogram is no longer stored in non volatile memory and is lost when power is removed This saves space in internal memory but eliminates the ability to list LIST command the subprogram The COMPRESS command should be used only after the subprogram has been debugged and tested Chapter 7 BASIC Language for the 3458A Execution Commands Subprogram CALL Subprogram PAUSE Knowing When a Subprogram is Paused Aborting a Subprogram Exiting a Subprogram Subprogram execution commands control the execution of a subprogram The syntax statements for the subprogram execution commands are shown below CALL sub_name PAUSE CONT The CALL command executes the named subprogram and waits for completion before executing other commands This means that no subsequent commands are accepted either from the GPIB interface or the front panel keyboard until the subprogram finishes The Ready Bit bit 4 in the 3458A Status Register remains 0 while the subprogram is executing When the subprogram finishes
230. circuitry ABORT 7 ABORT 7 CLEARS THE MULTIMETER S INTERFACE CIRCUITRY CLEAR DCL or SDC Syntax Examples LOCAL GTL Syntax Remarks Clears the multimeter preparing it to receive a command The CLEAR command does the following e Clears the output buffer e Clears the input buffer Aborts subprogram execution e Clears the status register bits 4 5 and 6 are not cleared if the condition s that set the bit s still exist e Clears the display e Disables triggering the previous triggering mode can be resumed by sending any multimeter command CLEAR 7 CLEAR 722 CLEAR 7 CLEARS ALL DEVICES DCL ON THE BUS SELECT CODE 7 CLEAR 722 CLEARS THE DEVICE SDC AT ADDRESS 22 SELECT CODE 7 Removes the multimeter from the remote state and enables its keyboard provided the keyboard has not been disabled with the multimeter s LOCK command LOCAL 7 LOCAL 722 Ifthe multimeter s LOCAL key is disabled by LOCAL LOCKOUT the LOCAL 722 command enables the keyboard but a subsequent remote command disables the keyboard Sending the LOCAL 7 command however returns front panel control even after a subsequent remote message 304 Appendix B GPIB Commands Examples LOCAL LOCKOUT LLO LOCAL 7 SETS GPIB REN LINE FALSE ALL DEVICES GO TO LOCAL YOU MUST NOW EXECUTE REMOTE 7 TO RETURN TO REMOTE MODE LOCAL 722 ISSUES GPIB GTL TO DEVICE AT ADDRESS 22 AFTERWARDS EXECUTING ANY MULTIMETER COMMAND OR R
231. cks The MSIZE command returns the total number of bytes of reading memory and the number of bytes of the largest unused block of subprogram state memory The SCRATCH command clears all subprograms and states from memory returning these memory areas to one contiguous block Also when power is cycled the multimeter combines fragmented blocks of memory wherever possible Chapter 6 Command Reference 203 NDIG NDIG NPLC Example Syntax Remarks Example e Query Command The MSIZE query command returns two responses separated by acomma The first response is the total number of bytes of reading memory The second response is the largest block in bytes of unused subprogram state memory Related Commands MCOUNT MEM MFORMAT RMEM DELSUB SCRATCH SUB SUBEND SSTATE 1Q OUTPUT 722 MSIZE QUERY MEMORY SIZES 20 ENTER 722 A B ENTER RESPONSES 30 PRINT A B PRINT RESPONSES 40 END Number of Digits Designates the number of digits to be displayed by the multimeter NDIG value value The value parameter can be an integer from 3 to 8 there is an implied 4 digit that is when you specify NDIG 3 the multimeter displays 34 digits Power on value 7 7 digits Default value 7 7 2 digits The NDIG command sets the maximum number of digits displayed It does not affect the A D converter s resolution or readings sent to memory or the GPIB bus The multimeter cannot display more digits than are resolve
232. commas We will use the NRDGS command which has two parameters as an example of a command with multiple parameters Press N Rdge Trig The display shows The first parameter in the NRDGS command is a numeric parameter that specifies the number of readings made per trigger event For example to specify 5 readings per trigger event press 5 The display shows Chapter 2 Getting Started 35 Using the MENU Keys 36 Chapter 2 Getting Started The second parameter of the NRDGS command specifies the event that initiates each reading Since this is not a numeric parameter a menu is available for this parameter Use the up or down arrow keys to cycle through the list of choices When the display shows Execute the command by pressing You have now selected five readings per trigger event If you execute the TRIG SGL command for example the multimeter will take five readings and then stop The NRDGS command is discussed in detail in Chapter 4 In addition to the configuration keys the multimeter has an alphabetic command menu that can be accessed using the shifted MENU keys labeled C E L N R S and T Each of these letters corresponds to the area you will enter into the command menu For example to enter the menu with commands starting with T press T Recall State The display shows You can now use the Menu Scroll keys up or down arrow keys to step through the menu in alphabet
233. ct power line frequency see Changing the Reference Frequency earlier in this chapter for details 10 OUTPUT 722 SUB 0 20 OUTPUT 722 RSTATE 0 30 OUTPUT 722 LFREQ LINE 40 OUTPUT 722 SUBEND 50 END You can also call the autostart subprogram CALL 0 command if you need to execute the subprogram without having to cycle the multimeter s power When you store a subprogram the multimeter stores the ASCII text in continuous memory and a compiled version of the subprogram in volatile memory When you call a subprogram the multimeter executes the compiled version this is why a subprogram executes faster than the equivalent commands sent over the bus When power is removed only the ASCII text is saved When power is reapplied the multimeter uses the ASCII text to generate a compiled subprogram You can compress subprograms using the COMPRESS command Compressing a subprogram removes the ASCII text from continuous memory leaving only the compiled version in volatile memory This makes more continuous memory space available but removes the subprogram from continuous memory all record of the subprogram will be destroyed when power is removed or the front panel Reset key is pressed Chapter 3 Configuring for Measurements 73 The following program statement compresses the previously stored subprogram named DCCUR OUTPUT 722 COMPRESS DCCURI1 Deleting The DELSUB command deletes a particular subprogram Fo
234. ctor which is necesary to convert the readings output in SINT format is not included in the above program The EXTOUT Signal 110 You can program the multimeter to output a TTL compatible signal on its Ext Out connector when a specified A D converter event occurs when the multimeter generates a GPIB service request or when the EXTOUT ONCE command is executed This signal can be used to synchronize external equipment to the multimeter The EXTOUT command s first parameter specifies the event that generates the signal and its second parameter specifies Chapter 4 Making Measurements the signal s polarity NEG low going POS high going The events that can generate a signal on the Ext Out connector are Reading complete e Burst of readings complete e Input complete Aperture waveform Service Request Executing the EXTOUT ONCE command Most of the above events apply to the multimeter s A D converter Figure 20 shows the relationship of these events to the A D converter activity Note The apparent time intervals shown in Figure 20 are for the illustration purposes only They are not meant to indicate the actual intervals produced by the multimeter Chapter 4 Making Measurements 111 112 A D Converter Activity Reading Complete Event EXTOUT RCOMP NEG EXTOUT RCOMP POS Burst Complete Event EXTOUT BCOMP NEG CNRDGS 3 EXTOUT BCOMP PQS CNRDGS 3 Input Complete Event EXTOUT ICOMP NEG
235. cuitry to determine when the input signal crosses a particular voltage on its positive or negative slope This is why you cannot use the LEVEL trigger or sample event or the LINE trigger event when making frequency or period measurements The power on or default level triggering values select zero volts positive slope You can control the level triggering voltage and coupling using the LEVEL command You can specify either the positive or negative slope using the SLOPE command Chapter 6 Command Reference 181 FSOURCE FSOURCE Example Syntax source Remarks Example The leftmost digit which is a half digit for most measurement functions is a full digit 0 9 for frequency measurements Readings made with autorange enabled take longer because the input signal is sampled to determine the proper range between frequency readings e For frequency and period measurements an overload indication means the voltage or current amplitude is too great for the specified measurement range It does not mean the applied frequency or period is too great to be measured Related Commands ACBAND FSOURCE FUNC LFILTER PER RES 10 OUTPUT 722 FSOURCE ACI SELECTS AC CURRENT AS INPUT SOURCE 20 OUTPUT 722e FREO O1 001 SELECTS FREQUENCY MEASUREMENTS 10mA 25 IRANGE 10ms GATE TIME 5 DIGITS RES 30 END Frequency Source Specifies the type of signal to be used as the input signal for frequency or period measurements
236. d l ciiai Query Parameter Description Parameter Equiv Description describes the parameter and OFF o Disables the beeper shows the choices or ranges available Power On Value shows the parameter used when power is applied Power on control last programmed value Default Value BW Default contrat ONCE shows the parameter used if you execute the command but do not specify a parameter Remarks Query Command The BEEF query command returns the present beeper contains special information mode Refer to Query Commands near the front of this chapter for more about the command information Examples show typical BASIC language programs or statements multimeter at address 722 Program syntax is applicable to HP Series 200 300 Computers BEEP coniral ON 1 Enables the beeper 2 Beeps once then returns to previous mode either OFF or ON Remarks The multimeter stores the control parameter in continuous memory the P parameter is not lost when power is removed Related Commands TONE Example OUTPUT 722 BEEP OFF DISABLES THE BEEPER Chapter 6 Command Reference 151 Introduction Language Conventions Command Termination Note Multiple Commands Parameters Defaulting Parameters The multimeter communicates with a system controller over the GPIB bus Each instrument connected to GPIB has a unique address The examples used in this manual are intended for Hewlett Packard Series 200 or 300
237. d perform the DCV autocal before performing the AC or OHMS autocal or perform ALL of the routines see second example below Suppose you intend to make 4 wire ohms measurements The DCV autocal routine increases the short term accuracy for all measurements and the OHMS autocal enhances resistance measurements and current measurements The following program performs the DCV autocal followed by the OHMS autocal 10 OUTPUT 722 ACAL DCV 20 OUTPUT 722 ACAL OHMS 30 END If autocal is secured it is not secured when shipped from the factory you must enter the security code to perform autocal refer to the ACAL command in Chapter 6 for more information You can perform all of the autocal routines DCV first followed by OHMS and AC by sending OUTPUT 722 ACAL ALL Always disconnect any input signals before performing autocal If you leave an input signal connected to the multimeter it may adversely affect the autocal and subsequent measurements For maximum accuracy we recommend performing ACAL ALL once every 24 hours or when the multimeter s temperature changes by 1 C from when it was last externally calibrated or from the last autocal We recommend that the calibrator store the multimeter s internal calibration temperature using Chapter 3 Configuring for Measurements 49 the CALSTR command this can be read later using the CALSTR command The following example shows how to use the TEMP command to monitor the m
238. d the mulitmeter averages six 10 PLC readings If you specify 1 second of integration time using the APER command the multimeter integrates a single reading for second With the APER command you can specify integration time from 500ns to Is in increments of 100ns The APER command is most commonly used when sampling a specific part of a signal such as a pulse or for digitizing You can also use the APER command to reject a noise signal of a specific frequency from the input signal To do this set the integration time equal to an integral multiple of the period of the signal to be rejected For example to reject noise at 100Hz period 10ms specify an integration time of 10ms 20ms 30ms etc You specify the measurement resolution as the last parameter of a function command FUNC ACV DCV etc or the RANGE command This parameter is called _ resolution since you specify it as a percentage of the command s max _input parameter see Specifying the Range earlier in this chapter The multimeter multiplies the specified _resolution parameter times the max input parameter to determine the measurement resolution To compute the resolution parameter use the equation _ resolution actual resolution maximum input x 100 For example suppose the maximum expected input is 10 VDC and you need 1 mVDC of resolution The equation evaluates to _ resolution 0 001 10 x 100 0 01 If you default the _resolution parameter
239. d be generally faster to change test points and stay on the same function if the test situation allowed HP 3458A DMM Figure 48 Measurement list and scan list increase test throughput when used with External Channel Close Increment tied to External Output and Pram Relay Multiplexers Channel close tied to external trigger Appendix D Optimizing Throughout and Reading Rate A Benchmark The benchmark used to show the affect of the various functions of the 3458A Multimeter will start with the most convenient but least rapid procedure of having the computer ask the dmm to change to a particular function make a measurement and transfer the measurement to the computer The benchmark will assume that all of the measurements will be made through a FET scanner of infinitely fast switching speed and of infinite dynamic range Hence the benchmark represents an artificial situation but one where the different modes of operation of the 3458A can be best illustrated The computer used is the 9000 Series 200 300 Times for other computers will vary depending on the GPIB turnaround time of the computer Results are shown in Figure 49 The DUT contains 25 resistance measurements 15 lt 10 kOhm 5 8 lt 100 kOhm 5 2 lt 10 kOhm 001 10 DCV measurements 5 lt 30 V 1 4 lt 10 V 01 1 lt 1 V 001 3 ACV measurements 1 lt 250 V 50 Hz 5 1 lt 1 V 5 kHz 0 075 Condit
240. d between measurement and the results are stored in the computer it is probably best to lose a little speed and store the data in Reading Memory in either DREAL or SREAL This avoids having to keep track of the scaling parameters needed for SINT and DINT A considerable savings in time at the right place in the testing task may be gained by the features of State Storage and Program Memory State memory is used to establish a static state of the instrument with a single command transfer over GPIB Initialization routines can set up the states that the programmer wishes to use in the test program during system dead time then the state can be called at will Program Memory is dynamic memory The state of the 3458A is dynamically changed as the sequence of operations programmed in Program Memory are stepped through as though the computer were controlling the sequence of events The measurements taken can be stored in Reading Memory to be accessed at a convenient time either to be transferred in raw form to the computer or to be post processed in the 3458A Again once the command string is transferred to the memory of the 3458A a simple command over GPIB initiates the measurement sequence More important than the time saved by passing the simple command the parsing routine of the 3458A actually compiles the Program Memory command string so that the measurement sequence can take place much faster than if the computer were controlling the operation To ea
241. d by the A D converter Query Command The NDIG query command returns the currently specified number of digits Refer to Query Commands near the front of this chapter for more information Related Commands DISP 10 OUTPUT 722 RESET RETURN TO POWER ON STATE 20 QUTPUT 7225 NDIG 8 DISPLAY 8 1 2 DIGITS 30 END Number of Power Line Cycles Specifies the A D converter s integration time in terms of power line cycles Integration time is the time during which the A D converter measures the input signal 204 Chapter 6 Command Reference NPLC Syntax NPLC power _line_cycles power _line_cycles The primary use of the NPLC command is to establish normal mode noise rejection NMR at the A D converter s reference frequency LFREQ command Any value 21 for the power_line_cycles parameter provides at least 60 dB of NMR at the power line frequency Any value lt 1 provides no NMR it only sets the integration time for the A D converter The ranges and the incremental step sizes for the power_line_cycles parameter are 0 1 PLC in 000006 PLC steps for 60Hz reference frequency LFREQ command or O 1 PLC in 000005 PLC steps for 50Hz reference frequency 1 10 PLC in 1 PLC steps 10 1000 PLC in 10 PLC steps Power on power_line_cycles 10 Default power_line_cycles 0 selects minimum integration time of 500ns The relationship of the integration time expressed in PLCs the A D converter s reference frequency LFREQ
242. d designates the storage format for new readings MFORMAT format format 198 Chapter 6 Command Reference Remarks MFORMAT The format parameter choices are Numeric format Query Parameter Equiv Description ASCII 1 ASCII 16 bytes per reading SINT 2 Single Integer 16 bits 2 s complement 2 bytes per reading DINT 3 Double Integer 32 bits 2 s complement 4 bytes per reading SREAL 4 Single Real IEEE 754 32 bits 4 bytes per reading DREAL 5 Double Real IEEE 754 64 bits 8 bytes per reading The ASCII format is actually 15 bytes for the reading plus 1 byte for a null character which is used to separate stored ASCII readings only Power on format SREAL Default format SREAL The multimeter indicates an overload by storing the value 1E 38 in memory instead of the reading When overload values are recalled to the display the value 1E 38 is displayed When overload values are transferred from reading memory to the GPIB output buffer they are converted to the overload number for the specified output format See the OFORMAT command for details When using the SINT or DINT memory format the multimeter stores each reading assuming a certain scale factor This scale factor is based on the present measurement function range A D setting and enabled math operations When you recall a reading the multimeter calculates the scale factor based on the present measurement function range A D setting and e
243. d in Table 1 20 Chapter 1 Installation and Maintenance Installation Verification Maintenance Replacing the Line Power Fuse Replacing a Current Fuse The following program verifies that the multimeter is operating and can communicate with the controller over the GPIB bus 10 PRINTER IS 1 20 OUTPUT 722 ID 30 ENTER 722 IDENTS 40 PRINT IDENTS 50 END If the multimeter has been correctly installed the message HP 3458A will be printed on the designated system printer If no message is printed make sure power is applied to the multimeter Also check the GPIB connections the interface address setting and the multimeter s address This section describes how to replace the multimeter s fuses and how to obtain repair service The line power fuse holder is located on the right side of the multimeter s rear panel Before replacing the fuse disconnect the multimeter s line power To replace the fuse use a small flatblade screwdriver to push in on the fuse cap and rotate it counterclockwise Remove the fuse cap and replace the fuse with the appropriate type see Table 4 The Keysight part number for the gray line power fuse cap is 2110 0565 Re install the fuse cap and apply power Table 4 Replacement Power Line Fuses and Caps Line Voltage Power Line Fuse 100 or 120 VAC Nominal 1 5ANTD Keysight Part Number 2110 0043 220 or 240 VAC Nominal 500MmAT SB Keysight Part Number 2110 0202
244. d or the contents are incomplete promptly notify the nearest Keysight Technologies office Chapter 1 Installation and Maintenance 15 Options and Accessories Table 1 lists the available options and Table 2 lists the available accessories for the multimeter Table 1 Available Options Description Option Part Number for Number Field Retrofit Extended Reading Memory expands to a total 001 03458 87901 of 148k bytes High Stability Reference 4ppm year 002 03458 80002 Front Handle Kit 907 5063 9226 Rack Flange Kit 908 5063 9212 Rack Flange Kit with handles 909 5063 9219 2 Additional Years of Return to Keysight W30 Hardware support Table 2 Available Accessories Description Model or Part Number Extra User s Guide Quick Reference Guide Calibration Manual 03458 90101 Assembly Level Repair Manual and Front Panel User s Guide Extra User s Guide to Keysight 3458A Front Panel Operation 03458 90007 Extra Quick Reference Guide 03458 90008 Extra Assembly Level Repair Manual 03458 90011 Extra Calibration Manual 03458 90017 User Defined Key Overlay 03458 84313 Switch Lockout Cap Qty 1 03458 44113 1 Meter GPIB Cable 10833A 2 Meter GPIB Cable 10833B 4 Meter GPIB Cable 10833C 0 5 Meter GPIB Cable 10833D Test Lead Set 34137A 30 Amp Current Shunt 34330A Kelvin Probe Set 4 wires plus ground 1m each 11059A Kelvin Clip Set 2 each 11062A The
245. d to a particular function key see example below The string returned by the DEFKEY query command is enclosed by double quotation marks regardless of whether single or double marks where used when it was specified e Related Commands LOCK MENU Chapter 6 Command Reference 169 DELAY DELAY Examples Syntax time Remarks Examples DEFKEY OUTPUT 722 DEFKEY 1 DCI 1 AZERO OFF NPLC 0 ASSIGNS COMMANDS TO F1 Clearing All DEFKEYs OUTPUT 722 DEFKEY DEFAULT CLEARS ALL DEFKEYS DEFKEY 10 OUTPUT 722 DEFKEY 1 RETURNS DEFINITION FOR KEY 1 20 ENTER 722 AS ENTERS DEFINITION INTO A VARIABLE 30 PRINT AS PRINTS DEFINITION 40 END A typical response returned by the above program is DCI 1 AZERO OFF NPLC 0 If nothing is assigned to DEFKEY 1 the above program returns DEFKEY F1 The DELAY command allows you to specify a time interval that is inserted between the trigger event and the first sample event DELAY time Specifies the delay time in seconds Delay time can range from 1E 7 100 ns to 6000 seconds in 10ns increments for direct or sub sampling DSAC DSDC SSAC or SSDC or 100 ns increments for all other measurement functions Specifying 0 for the delay sets the delay to its minimum possible value Power on time automatic determined by function range resolution and ACBAND setting Default time automatic determined by function range resolution and ACBAND setting The defau
246. ded the condition that set the bit s is no longer present If the SRQ line is false when you send SPOLL the status register s contents are not changed The SPOLL command differs from the STB command in that STB interrupts the multimeter s microprocessor Thus with STB the multimeter always appears to be busy bit 4 clear SPOLL simply extracts the status byte without interrupting the microprocessor Therefore you can use SPOLL to monitor the readiness of the multimeter for further instructions e If data is in the output buffer when you send the SPOLL command that data remains intact If data is in the output buffer when you send the STB command however the data is replaced by the status data 10 P SPOLL 722 SENDS SERIAL POLL PLACES RESPONSE INTO P 20 DISP P DISPLAYS RESPONSE 30 END Appendix B GPIB Commands TRIGGER GET TRIGGER GET Syntax Remarks Examples If triggering is armed see TARM command the TRIGGER command Group Execute Trigger triggers the multimeter once and then holds triggering TRIGGER 7 TRIGGER 722 The TRIGGER command generates a single trigger just as if the TRIG SGL command was executed It will not however trigger the multimeter if triggering is not armed TARM command If subprogram memory execution is suspended by the PAUSE command multimeter command set the TRIGGER command resumes subprogram execution but does not generate a single trigger TRIGGER 7 SEND
247. digits of resolution Power on resolution none At power on the resolution is determined by the NPLC command which produces 8 digits The power on value for NDIG masks 1 display digit causing the multimeter to display only 74 digits You can use the NDIG 8 command to display all 8 2 digits refer to the NDIG command for details Default resolution For frequency or period measurements the default resolution is 00001 which selects a gate time of 1s and 7 digits of resolution For sampled ACV or ACDCV the default resolution is 0 01 for SETACV SYNC or 0 4 for SETACV RNDM For all other measurement functions the default resolution is determined by the present integration time e Query Command The FUNC query command returns two responses separated by a comma The first response is the present measurement function The second response is the present measurement range this is the actual range not necessarily the value specified for max _ input The FUNC query command does not indicate the autorange mode Use the ARANGE query to determine the autorange mode Refer to Query Commands near the front of this chapter for more information e Related Commands ACDCI ACDCV ACI ACV APER DCI DCV DSAC DSDC FREQ OHM OHMF PER RATIO NPLC RES SETACV SSAC SSDC Chapter 6 Command Reference 185 ID Examples In the following program line 10 allows _resolution in line 20 to control the resolution The
248. ding memory to the GPIB output buffer they are converted to the overload numbers for the specified output format Refer to Sending Readings Across the Bus later in this chapter for more information Recalling Readings You can recall readings from memory using the reading number or by a method called implied read Regardless of the specified reading memory format recalled readings are output in the format specified in the OFORMAT command refer to Sending Readings Across the Bus later in this chapter for more information Before recalling readings you may want to determine the number of readings stored This can be done using the MCOUNT query command The following program returns the total number of stored readings 10 OUTPUT 722 MCOUNT 20 ENTER 722 A 30 PRINT A 40 END Using Reading Numbers The multimeter assigns a number to each reading in reading memory The most recent reading is assigned the lowest number 1 and the oldest reading is assigned the highest number Reading numbers are always assigned in this manner regardless of whether the LIFO or FIFO mode is used The RMEM command allows you to use the reading number s to copy a reading or group of readings from memory to the output buffer The RMEM command does not destroy readings in memory it merely copies the reading s to the output buffer The RMEM command turns reading memory OFF This means all previously stored readings remain intact and new readings are no
249. dings in STATS MIN Lower limit for PFAIL NSAMP Number of samples in STATS OFFSET Subtrahend in NULL and SCALE operations PERC Percent value for PERC operation REF Reference value for DB operation RES Reference impedance for DBM operation SCALE Divisor in the SCALE operation SDEV Standard deviation in STATS UPPER Largest reading in STATS PFAILNUM The number of readings that passed PFAIL before a failure was encountered You can write a value to any math register except SDEV using the SMATH command For example to place the value of 22 in the DEGREE register send OUTPUT 722 SMATH DEGREE 22 You can read the value in any math register using the RMATH command For example the following program reads and prints the value in the RES register 10 OUTPUT 722 RMATH RES 20 ENTER 722 A 30 PRINT A 40 END The NULL operation subtracts a value from each reading following the first reading The equation is Chapter 4 Making Measurements 117 118 Result 20 30 40 50 60 70 80 Reading OFFSET Where OFFSET is the value stored in the OFFSET register typically the first reading Reading is any reading following the first reading After you select the NULL operation the first reading made real time or the first reading taken from memory post process is stored in the OFFSET register The value of this reading is then subtracted from all subsequent readings If you do not want the first reading
250. dix D Optimizing Throughout and Reading Rate 337 338 Still Faster A considerable increase in throughput can be had if you use TRANSFER statements instead of OUTPUT and ENTER statements Further the juxtaposition of some commands improve the measurement speed Notably the sequence for DELAY and ACBAND when working with ACV can make a large difference in execution speed The proper sequence is DELAY lt gt ACBAND lt gt ACV lt range gt If you want to change the default settling times when you change a function always change the DELAY command first It is also faster in many cases to remain on one integration time rather than change For example to get 6 1 2 digits resolution the 3458A can be set to APER 10E 5 100 us where it can take almost 10 000 readings per second If measurement calls for only a few measurements with this resolution and a greater number with less resolution it still may be faster to leave the integration time at 100 us and take all the measurements there It takes about 6 to 10 ms for the 3458A to change integration time At about 10 000 readings per second the 3458A can take one hundred 6 1 2 digit readings in that time This last program uses transfers and the proper command sequence to achieve the greatest possible throughput for the benchmark program Execution time 360 s Program Memory Download Time 05 s Reading Transfer time 05 s 10 OPTION BASE 1 20 DIM Command 1000 BUFFER 30
251. duces 8 4 digits The power on value for NDIG masks display digit causing the multimeter to display only 7 4 digits You can use the NDIG 8 command to display all 8 2 digits Default _ resolution Chapter 6 Command Reference 225 RESET RESET Remarks Examples For frequency or period measurements the default _resolution is 00001 which selects a gate time of 1s and 7 digits of resolution For sampled ACV or ACDCYV the default resolution is 0 01 for SETACV SYNC or 0 4 for SETACV RNDM For all other measurement functions the default resolution is determined by the present integration time For analog measurements the resolution parameter of the RES command operates slightly differently than the resolution parameter of a function command FUNC ACV DCV etc or the RANGE command When used with the RES command _resolution is multiplied times the range to determine the actual resolution When used with a function command or the RANGE command resolution is multiplied times that command s max _ input parameter The max _input parameter may or may not be the value of a measurement range Query Command The RES query command returns the specified _resolution Refer to Query Commands near the front of this chapter for more information e Related Commands ACDCI ACDCV ACI ACV APER DCI DCV FREQ FUNC NPLC OHM OHMF PER RANGE In the following program line 10 allows _resolution in line 30 to
252. e the SSAC command is used to digitize a 10 kHz signal with a peak value of 5V The SWEEP command instructs the multimeter to take 1000 samples Num_ samples variable with a 2us effective_interval Eff int variable The measurement uses the default level triggering for the sync source event trigger from input signal 0 AC coupling positive slope Line 120 generates a SYN event and transfers the samples directly to the computer Lines 240 through 410 sort the sub sampled data to produce the composite waveform The composite waveform is stored in the Wave form array 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_samples Inc 1I J K L DECLARE VARIABLES Chapter 6 Command Reference 249 SWEEP 250 30 40 50 60 70 80 90 Num_samples 1000 DESIGNATE NUMBER OF SAMPLES Eff int 2 0E 6 DESIGNATE EFFECTIVE INTERVAL INTEGER Int_samp 1 1000 BUFFER CREATE INTEGER BUFFER ALLOCATE REAL Wave_form 1 Num_samples CREATE ARRAY FOR SORTED DATA ALLOCATE REAL Samp 1 Num_samples CREATE ARRAY FOR SAMPLES ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS ASSIGN Int_samp TO BUFFER Int_samp ASSIGN BUFFER I O PATH NAME 00 OUTPUT Dvm PRESET FAST LEVEL SLOPE SSRC LEVEL SSDC 10 01 FAST OPERATION TARM SYN LEVEL SYNC SOURCE 0V POSITIVE SLOPE 05 DEFAULT VALUES SUB SAMPLING SINT OUTPUT FORMAT 10V RANGE 10 OUTPUT Dvm SWEEP Eff _int Num_samples 15 2ys EFFECTIVE INTERVAL 1000 SAMPLES 20
253. e cable connector Figure 4 shows a typical GPIB connection between the multimeter and a controller 1 GPIB General Purpose Interface Bus is an implementation of IEEE Standard 488 1978 and ANSI MC 1 1 Chapter 1 Installation and Maintenance 19 Figure 4 Typical GPIB Connections A total of 15 devices can be connected together on the same GPIB bus The cables have single male female connectors on each end so that several cables can be stacked The length of the GPIB cables must not exceed 20 meters 65 feet total or 2 meters 6 5 feet per device whichever is less The GPIB Address You can change the multimeter s GPIB address using the ADDRESS command Refer to Changing the GPIB Address in Chapter 2 for a procedure on how to change the GPIB address The multimeter leaves the factory with the address set to decimal 22 The corresponding ASCII code is a listen address of 6 and a talk address of V Note The examples in this manual are intended for Hewlett Packard Series 200 300 computers using the BASIC language They assume a GPIB interface select code of 7 and a device address of 22 resulting in a combined GPIB address of 722 Mounti ng the The multimeter comes equipped with four feet which allow it to be used as Multimeter 2 bench instrument It also has two tilt stands that allow you to elevate the front of the multimeter The multimeter can be mounted in a standard 19 inch rack using the optional rack mount kits liste
254. e exceeded when measuring a signal with a frequency gt 2MHz and an amplitude gt 120 of range signals lt 120 of range with frequencies up to 12MHz do not cause slew rate errors The multimeter s triggering hierarchy trigger arm event trigger event and sample event applies to direct sampling This means that these events must occur in the proper order before direct sampling begins Refer to Chapter 4 for more information on the triggering hierarchy For direct sampling you can use either the TIMER sample event and the NRDGS n TIMER command or the SWEEP command SWEEP is the simpler to program The NRDGS and SWEEP commands are interchangeable the multimeter uses whichever command was specified last When using the SWEEP command the sample event is automatically set to TIMER e When direct sampling an input signal with a frequency content gt 1 MHz the first sample may be in error because of interpolator settling time To ensure the first sample is accurate insert a 500ns delay before the first sample DELAY 500E 9 command Direct Sampling The following program is an example of DC couple direct sampled Exampl e digitizing The SWEEP command specifies an interval of 30us and 200 samples Level triggering is set for 250 of the 10V range 250 of 10V 25V The samples are sent to reading memory in DINT format The samples are then sent to the controller converted and printed By deleting line 110 samples will be transfer
255. e interval between readings and its second parameter specifies the number of readings The SWEEP and NRDGS commands are interchangeable the multimeter uses whichever was specified last in the programming For example the following program also takes 8 readings Chapter 4 Making Measurements 85 86 10 OPTION BASE 1 20 DIM Rdgs 8 with a 1 second interval between readings this is shown in Figure 18 COMPUTER ARRAY NUMBERING STARTS AT 1 DIMENSION ARRAY FOR 8 READINGS 30 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 SWEEP 1 8 1 SECOND INTERVAL 8 READINGS TRIGGER 50 ENTER 722 Rdgs SYN EVENT ENTER EACH READING 60 PRINT Rdgs 70 END Note Making Delayed Readings PRINT READINGS 80 END When using the TIMER sample event or the SWEEP command autorange is disabled You cannot use TIMER or SWEEP for AC or AC DC voltage measurements using the synchronous or random methods SETACV SYNC or RNDM or for frequency or period measurements TRIG SYN OCCURS 1 SEC 1 SEC 1 SEC TIMER TIMER TIMER 1 SEC 1 SEC 1 SEC 1 SEC TIMER TIMER TIMER SUN Paa aag RDG o paa ae p R pen ibe 1 Figure 18 TIMER or SWEEP interval The DELAY command allows you to specify a time interval that is inserted between the trigger event and the first sample event For example in the following program the specified delay interval is 2 seconds and the SWEEP interval is 1 seco
256. eading stored is the first reading returned when you recall readings without specifying reading numbers implied read method which is discussed later in this chapter If you fill the reading memory in the FIFO mode all stored readings remain intact and new readings are not stored In the LIFO mode the last reading stored is the first reading returned when you recall readings without specifying reading numbers If you fill reading memory in the LIFO mode the oldest readings are replaced by the newest readings You enable reading memory and specify the mode using the MEM command Specifying a reading memory mode erases any previously stored readings For example to specify reading memory using the LIFO mode send OUTPUT 722 MEM LIFO The multimeter is now enabled to store readings After storing readings you can disable reading memory and leave all stored readings intact by sending OUTPUT 722 MEM OFF Later you can resume the previous mode to store additional readings without Chapter 4 Making Measurements clearing any stored readings by sending OUTPUT 722 MEM CONT Memo ry Formats Readings can be stored in one of five formats ASCII single integer SINT double integer DINT single real SREAL or double real DREAL The memory space required for each format is ASCII 16 bytes per reading SINT 2 bytes per reading DINT 4 bytes per reading SREAL 4 bytes per reading DREAL 8 bytes per reading To determ
257. ear Resolution Gate Time Readings eect measurement resolution Range 0 C 55 C 7 For Maximum Input 1 Hz 40 Hz pace 1s 9 23 specified to fixed range 1 s 25 0 05 ofReadi gt 0 0001 100 ms 9 6 operation For auto range ee i pp TN gt 0 001 10 ms 73 the maximum speed is 30 ae ee gt gt 0 01 1 ms 215 readings sec for ACBAND 25 ms 100 ns 01 ofReading gt 0 1 100 us 270 gt 1 kHz Actual Reading Speed is the longer of 1 period of Measurement Technique Trigger Filter the ae can m t ort t Reciprocal Counting Selectable 75 kHz Low Pass Trigger Filter eee P Page eee ae Time Base Slope Trigger 1 2 sec 10 MHz 0 01 0 C to 55 C Positive or Negative Level Trigger 500 of Range in 5 steps 294 Appendix A Specifications 7 I Digitizing Specifications General Information The 3458A supports three independent methods for signal digitizing Each method is discussed below to aid in selecting the appropriate setup best suited to your specific application DCV Standard DCV function This mode of digitizing allows signal acquisition at rates from 0 2 readings sec at 28 bits resolution to 100k readings sec at 16 bits Arbitrary sample apertures from 500 ns to 1 sec are selectable with 100 ns resolution Input voltage ranges cover 100 mV to 1000 V full scale Input bandwidth varies from 30 kHz to 150 kHz depending on the measurement range DSDC Direct Sampling DC Coupled measurement technique DSAC Direct Sampling AC
258. ecuted inside a subprogram The only commands which cannot be stored are CONTINUE COMPRESS DELSUB and SCRATCH Three conditional and looping commands are provided for use within subprograms How Many Different Subprograms Can Be Stored The exact number of subprograms which can be stored in 3458A memory Chapter 7 BASIC Language for the 3458A 273 depends on the individual sizes of the subprograms A typical subprogram containing 10 commands including the SUB and SUBEND commands might average about 600 bytes Refer to chapter 3 for more information on memory usage Can I Nest Subprograms Yes Nesting subprograms is the ability to have one subprogram call execute another subprogram You can nest up to 10 subprograms Writing and Loading Subprograms 274 Note The subprogram example programs in this section illustrate relatively simple 3458A operations which you can copy and use in more complex mainline programs of your own design This section also shows how to create and edit subprograms PROGRAMMING HINT You should execute the SCRATCH command and download the subprograms from your system controller at the beginning of your test system program This helps memory management for the 3458A and ensures that the subprograms are downloaded and ready when they are needed Executing the SUB command instructs the 3458A to store all subsequent commands until the SUBEND command in the specified subprogram Subprogram na
259. ed Voltage Jitter 6th 7 Not to scale for emphasis oniy 0 0 1 007 2E 007 Time s Appendix E High Resolution Digitizing With the 3458A A A D converter configuring the 58 AC bandwidth 105 current 64 measurements configuring for 62 voltage 62 voltage method specifying the 64 AC DC current 64 voltage 62 ACAL 157 ACBAND 158 Accessories options and 16 ACDCI 159 ACDCI example fast 107 ACDCI key 29 ACDCV 159 ACDCV example fast analog 106 fast synchronous 106 ACDCV key 29 ACI 159 ACI example fast 107 ACI key 29 ACV 159 ACV example fast analog 106 fast synchronous 106 ACV key 29 ADDRESS 159 Address changing the GPIB 43 key 42 reading the GPIB 42 Analog ACDCV example fast 106 ACV example fast 106 RMS conversion 64 INDEX Annunciator AZERO OFF 27 ERR 27 LSTN 27 MATH 27 MORE INFO 27 MRNG 27 REM 27 SHIFT 27 SMPL 27 SRQ 27 TALK 27 APER 160 Aperture waveform 114 Applying power 25 ARANGE 160 Arming multiple trigger 84 ASCII 92 Auto key 30 Autocal running 49 when to use 49 Autocalibration 48 Autorange 53 Autoranging and manual ranging 29 Autostart subprogram 73 Autozero 61 AUXERR 161 AZERO 162 AZERO OFF annunciator 27 B Back Space key 38 Bandwidth AC 105 specifying 66 BASIC language 20 BEEP 164 Before applying power 25 INDEX 363 Binary coding two s complement 92 Buffering external
260. ed in Reading Memory as the measurements are made At the end of the measurement sequence the readings are transferred from Reading Memory to the computer using a FOR NEXT loop Except for the convenience of data transfer there is no marked improvement in the speed of the measurement in this case If the data were transferred viaa TRANSFER statement to the computer there would be more time savings Using Program Memory Subprogram Program test execution time 1 06 s program memory download time 260 s reading transfer time 17 s 2030 2040 2050 2060 2070 SUB Program REAL Dnld_time Exe time Tns_time DIM A 37 Dnlid_time T1MEDATE OUTPUT 722 PRESET MFORMAT SREAL OUTPUT 722 SUB 1 MEM FIFO OHM 1E4 NPLC 0 DELAYO NRDGS 15 TRIG SGL 2080 OUTPUT 722 0HM 1E5 NRDGS 8 TRIG SGL 2090 OUTPUT 722 OHMF 1E3 APER 20E 6 DELAY 1 NRDGS 2 TRIG SGL 2100 OUTPUT 722 ACV 250 ACBAND 250 DELAY 1 NRDGS 1 TRIG SGL 10 OUTPUT 722 ACV 10 ACBAND 25000 DELAY 01 TRIG SGL 20 OUTPUT 722 DCV 10 NPLC 0 DELAY 0O NRDGS 6 TRIG SGL 30 OUTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY 01 NRDGS 1 TRIG SGL 40 OUTPUT 722 DCV 10 NPLC 0 DELAY 0 NRDGS 3 TRIG SGL SUBEND 50 Dnld_time TIMEDATE Dnld_ time 60 E 70 OUTPUT 722 CALL 1 80 Exe time TIMEDATE Exe time 2190 Tns_time TIMEDATE 2200 FOR I 1 TO 37 2210ENTER 722 A I 2220 NEXT I 2230 Tns_time TIMEDATE Tns_ time 2240 SUBEND xe time TIMEDATE MO MN NY NY NY NY NH Again the structure o
261. ed primarily by the AC bandwidth setting which is discussed later in this section the measurement method changes to random sampling so that a measurement can be made You can prevent the measurement method from changing using the SSRC command You can also pace synchronous sampling to a signal on the Ext Trig connector using the SSRC command Refer to the SSRC command in Chapter 6 for more information and example programs When using the LEVEL sync source it is possible for noise on the input signal to produce false level triggers and to cause inaccurate readings For accurate readings ensure that your nearby environment is electrically quiet and use shielded test leads Enabling level filtering LFILTER ON command reduces the sensitivity to this noise Refer to the LFILTER command in Chapter 6 for more information The input signal is always DC coupled for synchronous sampling regardless of the specified ACV or ACDCV measurement function When ACV is specified the DC components are mathematically subtracted from the reading This is important to consider since the combined AC and DC voltage levels may cause an overload condition even though the AC voltage alone normally would not Chapter 3 Configuring for Measurements 63 Analog RMS Conversion Random Sampling Conversion Specifying the AC Voltage Method AC or AC DC Current The analog RMS conversion directly integrates the input signal and is the method selected when power is a
262. ed signal contains no frequency components higher than F then the original signal can be recovered without distortion aliasing if it is sampled at a rate that is greater than 2F samples per second In practice the multimeter s sampling rate must be at east twice the highest frequency component of the signal being measured The sampling rate is the reciprocal of the time interval specified by the TIMER command or the effective_interval specified by the SWEEP command For example assume the effective_interval is specified as 20us The sampling rate is then 1 20us 50 000 samples per second Figure 25 shows a sine wave sampled at arate slightly less than 2F As shown by the dashed line the result is an alias frequency which is much different than the frequency of the signal being ueasured Input signal Alias frequency Figure 25 Aliasing caused by undersampling Some digitizers have a built in anti aliasing low pass filter with a sharp cutoff at a frequency equal to 1 2 the digitizer s sampling rate This limits the bandwidth of the input signal so that aliasing cannot occur Since the multimeter has a variable sample rate for DCV digitizing and to preserve the upper bandwidth for high frequency measurements no anti aliasing filter is provided in the multimeter If you are concerned about aliasing you should add an external antialiasing filter Chapter 5 Digitizing 131 Level Triggering 132 Level Triggering Examples
263. ee 88 Event Combinations 0 cecceseeceeceseeseeneeenees 88 Reading Formats cccccccsccesscesseesseeteceeenteeeneeenes 92 ASC M ee rE ER E EE A 92 Single and Double Integer s ssseseeeeeseeeeeeseseeee 92 Two s Complement Binary Coding 92 Single Reall cicvts niet tities tcandecem teed 93 SREAL Example anicent nonono 93 Double R als anr iyana 94 Using Reading Memory ccccecssesceseceteeeteeeees 94 Memory Formats ccccscecsscesseceeteeceneeeeeaes 95 Overload Indication eceeceeseereeteeteeneeees 96 Recalling Readings 0 cccccecsceseereeseeetteensees 96 Using Reading Numbers cecseseeteees 96 Using Implied Read cceececseeeseetteeteees 97 Sending Readings Across the Bus cceeeeeee 98 Output Formats 2 0 0 ec eeceeeseeesteeeeteeeeeeeeeeeeees 98 Overload Indication 2 0 0 0 ecceceeseeseeeseeeeeeees 99 Output Termination 20 0 cccecceseeseeereesteenseens 99 Using the SINT or DINT Output Format 99 SINT Example icscsecccsccicsseesdeiecctsessccdiewcctancs 99 DINT Example dvs deisnaciaieniaccunts 100 Using the SREAL Output Format 101 Using the DREAL Output Format 0 0 101 Increasing the Reading Rate cee eeeeeeeeeeees 102 High Speed Mode cesceseeeeeeceeeeeeeeeeeeeees 102 Configuring for Fast Readings eeee 103 PRESET FAST Command eee 103 Integration Time and Resolution
264. eed Transfer Across the Bus in Chapter 4 for more information 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_samples I J K CREATE INTEGER VARIABLES 30 Num_samples 200 1200 SAMPLES 30 ASSIGN Dvm TO 722 DESIGNATE MULTIMETER ADDRESS 40 ASSIGN Buffer TO BUFFER 4 Num_samplesl ASSIGN BUFFER I O PATH NAME 45 SAMPLES 4 BYTES SAMPLE 200 SAMPLES 800 BYTES 50 ALLOCATE REAL Samp 1 Num_samples CREATE REAL ARRAY FOR SAMPLES 60 OUTPUT Dvm PRESET FAST DINT FORMATS TARM SYN TRIG AUTO 70 OUTPUT Dvm SWEEP 30E 6 200 30ys INTERVAL 200 SAMPLES 80 OUTPUT Dvm DSDC 10 DIRECT SAMPLING 10V RANGE 90 OUTPUT Dvm LEVEL 250 DC LEVEL TRIGGER AT 250 OF RANGE 25V 00 OUTPUT Dvm TRIG LEVEL LEVEL TRIGGER EVENT 10 OUTPUT Dvm MEM FIFO ENABLE READING MEMORY FIFO MODE 20 TRANSFER Dvm TO Buffer WAIT TRANSFER SAMPLES TO CONTROLLER 30 OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR DINT FORMAT 40 ENTER Dvm S ENTER SCALE FACTOR 50 FOR I 1 TO Num_samples 60 ENTER Buffer USING W W J K ENTER ONE 16 BIT 2 S COMPLEMENT 61 WORD INTO EACH VARIABLE J AND K STATEMENT TERMINATION NOT 65 REQUIRED W ENTER DATA AS 16 BIT 2 S COMPLEMENT INTEGER 70 Samp I J 65536 K 65536 K lt O CONVERT TO REAL NUMBER 80 R ABS Samp I USE ABSOLUTE VALUE TO CHECK FOR OVLD 90 IF R gt 2147483647 THEN PRINT OVLD IF OVERLOAD OCCURRED PRINT MESSAGE 200 Samp I Samp I S APPLY SCALE
265. eeeceeeeeeeeeeeseceeceeeeeeeeesecaeteeeateeees 56 Configuring the A D Converter cee 58 PULOZOLO aevecess a Seceteescwestelcesal ae aens ieta teei 61 Offset Compensation c cecccesceesseesecetteeseees 62 Fixed Input Resistance ececeseeseeseeneeeteeees 62 Configuring for AC Measurements eeeeees 62 AC or AC DC Voltage oo cccecceccceseeteeeteeetees 62 AC or AC DC Current oo ceeeeeeeeeeeeees 64 Frequency or Period ecceecceseeseeeseneeeteeaeees 65 Specifying Bandwidth 0 ceeeeeeseeeereeneeees 66 Setting the Integration Time eee 67 Specifying Resolution cccceesceseeteeeteeeees 68 Configuring for Ratio Measurements 000 70 Specifying Ratio Measurements eee 71 Using Subprogram Memory cccccseeteeeteeeeees 71 Storing a Subprogram cccesseseeeeteesteeeees 71 Executing a Subprogram 0 cceccesseesseesteeees 72 Suspending Subprogram Execution 72 Nested Subprograms c ccceseeeceeteeteeseeeeeeees 73 Autostart Subprogram ceeeeeeseeseereeeeeeeees 73 Compressing Subprograms ceseeseeeeees 73 Deleting Subprograms cceeceseeeeeeteeteees 74 Using State Memory ou eecccceesseceseeeeeeeeeesseenseees 74 Storing States sicci ie na 74 Recalling States cccccccssecesceseseeeeeseeseessees 74 Contents 7 Deleting States ce eceesceseeseceeeeeeeeeeeeeneeneeeeees 75
266. eeees 262 Variables and Arrays ccccsceeseesseeteeesteeteeees 262 Math Operations cccecccesseeseeeteesteeeteeseeees 262 Subprogram Definition Deletion 263 Subprogram Execution Commands 263 Looping and Branching ecceeeeeeeeeeeeees 263 Binary Programs cccceeseeseeeeceeeeeeeeeeteeseees 263 New Multimeter Commands ceeeeeseeeeeeees 264 3458A BASIC Language Example Program 265 Sample Results From Program Execution 266 Variables and Arrays cccccceeccesseesseeseceteeeteeeeeeees 266 Type Declarations cccccecceesseeseeeteeeteeeeeees 266 Type Conversions cccccecsesseeeseeteceteeeseennes 267 Using Variables ccccccscecseesseeseceteenteeeseees 267 Variables for Data Storage c cceeeeees 268 Numeric Calculations 200 0 cc eeeeeeceeeeeeees 268 Reading Multimeter Values 0 0 eee 268 DATTA S 3 ie alist sbuteees Seaietes Wetees OA a 268 Filling Arrays oran ai aate aasi 269 Array SIZE heo ane e eE E E N ea 269 Purging Arrays and Variables 269 General Purpose Math ccccccecsesseeeseeeteeeeeeees 269 Math Operators eeeceesceseeeececeeeeeseeeeeeeeeeeees 270 General Math Functions 0 ceeeeeeeeeee 270 Logarithmic Functions ccseseseteees 270 Trigonometric Functions ceeeeeeeeee 271 Logical Functions ccecceesseeseeeteeeteeeteees 271 Binary Functions 0 ceceesceseeeeeeeeeeeereeee
267. eeeteetecneeeeeeeeeeees 37 Digits Displayed 0 0 eeeseseereeteeeeceeeeeeeeeeees 39 Recall siirat aii 39 User Defined Keys ccceccesseessecseeeteeeseeeseeesees 40 Installing the Keyboard Overlay c eee 41 Operating from Remote cceececeeseeseceeeeeeeeees 42 Input Output Statements 20 0 0 eee eeeeeeeeeeeeee 42 Reading the GPIB Address 0 0 ceeccesseeteereeeee 42 Changing the GPIB Address eeeeeeeees 43 Contents Sending a Remote Command eeeeeee 43 Getting Data from the Multimeter 0 0 0 0 43 The Local Key a ssii ciiiieistisdatindsitentdaa then 44 Chapter 3 Configuring for Measurements Introduction isseire tae eee aE 47 General Configuration ccceceeeeceteeeesereeneenee 47 Self Test sazcacesvecussestnccisiosseiteeneantesrinteaeaaataniass 47 Reading the Error Registers seseeeeeeseeeeee 48 Calibration oceneni S 48 Selecting the Input Terminals eee 50 Guarding sivseceedcceesss cides iesenii peiie 51 Suspending Readings ccccscsseesteeteeeeeeees 51 Presetting the Multimeter 00 0 ceeeeeeeeseeeees 52 Specifying a Measurement Function 53 AUtOTAN GES eee eeeccceeeeeeececeneeeeaeeesaeeeeaeeceaeeceeeeees 53 Specifying the Range eeeeeeeeeeeeeteeneeeee 54 Configuring for DC or Resistance Measurements 54 DC Voltage sssscasisscvivsaassnecanarvencdscaveaisaannstigccennaas 54 DCO Current tia yssi phe HEAR 55 REeSIStANCE oo e
268. eelastivdaesiosieea ite 152 Query Commands ecceececseeseeeteeeeeeeteeesees 153 Commands by Functional Group eee 155 Commands vs Measurement Functions 156 ACAD wcsckinscts dsunsedtaannissmucass O 157 ACBAND raionar e 158 ACDCI ACDCV ACI ACV nosses 159 ADDRESS ercana 159 8 Contents PRA NG LE evarectecranletectennietaenatacteaniveacne 160 AUXERR staccato trlicsthil casi ceecdapercentes 161 VA RRR eee nee tere mentee 162 BEEP oosisiiisseniiisssriiiisoseiri irisse rrrsreren 164 N PEAT E A E 164 CA A A oda ace 164 CALNUM sp tere eece scars ones 165 CATS Ce e a A 165 COMPRESS ov ccccccssssssssscsssesssssescssesssseeecesesen 166 COI oacattactenuanctoctetnagiaaeensican 167 E E E 167 TC TOG ea 168 DIEA S a gcssiee cerca fectath eee cher asi enone 168 DIEI A A A 169 DELAY oere E 170 DIEI SIO S 171 DIAGNOST ooncceccccsssscsssesessesccssescssesesseseesevesans 171 DISP ee er E Eni 171 TGA DI D OR 172 EMASR lt cccsisteareartscsaasteneastdscunssoteiadarsnesioreanetes 174 ISINA DEE 176 ERR eeen E E E 177 ERRSTR onssas 178 EXTOUT vacsicccarsareonesisineestcienestorassckorsstaccdeta 178 POED oeae 180 FREQ coecceccssscscssssssseccsssesssseccssssssusscsnesessuseesses 181 BSOURCE wes ecoiisedesdeahannewcusauince 182 LOIN ices tesisiee veces ooaticeactineteeun 183 ID seeps teat ences ee 185 INBUF secs Ss fosccteseccaecvacdiatvool tdeesciasendamcleniies 185 DSO ode scene asc lessen natu mest 187 IGE E
269. een subprograms you may have problems when you cycle power This is due to the way that the subprograms are stored internally to conserve memory The subprogram executable code is actually rebuilt internally during the multimeter s power on start up routines Use the FILL command carefully It does not work if power is cycled the command is effectively deleted from the subprogram at this time Use separate LET statements for each value assigned Numeric Operations Chapter 7 BASIC Language for the 3458A Subprogram Definition Deletion Subprogram Execution Commands Looping and Branching Binary Programs DIV MOD ABS SQR LOG EXP LGT SIN COS ATN Binary Operations AND OR EXOR NOT BINAND BINCMP BINEOR BINIOR BIT ROTATE SHIFT SUB sub_name Identifies where the subprogram begins and assigns the name to the subprogram SUBEND sub_name Identifies where the subprogram ends and also terminates the entry of the subprogram DELSUB sub_name Deletes the specified subprogram from internal memory SCRATCH Deletes scratches all 3458A subprograms variables and arrays from internal memory CAT Lists the names of all 3458A subprograms simple variables stored states and arrays that are presently stored in internal memory limited to 400 characters LIST sub_name Lists the specified subprogram limited to 400 characters COMPRESS sub_name Removes the text of the specified subprogram from memo
270. eg Ew atoocowenren G Missy analog signal and ae tir ending with results meaningful to the user pales _ gt ANALYSIS rane ee ae S a 1005 DATA PRESENTATION oe To avoid signal distortion caused by aliasing the effective sample interval must meet the Nyquist criterion of 1 2fp In direct sampling the effective sample interval is the actual time between measurements selected Therefore through the track and hold path or through the DCV path explained in the next section the maximum signal frequency is 25 kHz or 50 kHz for 20 us or 10 us sample intervals respectively If higher frequencies are present then a low pass filter of bandwidth f or less should be inserted in the signal path For sequential sampling the effective sample interval is the time between samples of the reconstructed wave form refer to Figure 51 If you select an effective sampling interval of less than 35 ns the bandwidth of the track and hold path 12 MHz eliminates most distortion caused by aliasing If the effective sample interval is greater than 35 ns and frequencies higher than 12 MHz are present an external filter is necessary as well 350 Appendix E High Resolution Digitizing With the 3458A Figure 51 Direct sampling acquires the TOD wave form in one pass of i the input Sequential COO y POEmo sampling requires a broo repetitive signal where Direct sample the period is reconstructed in several passes The numbers Ef
271. en One reading is then taken per SYN event until the specified number of readings are completed SYN SYN AUTO EXT TIMER After the controller requests data 2 both SYN events are LINE LEVEL satisfied One reading is then taken per sample event until the specified number of readings are completed 1 The LEVEL event occures when the specified voltage is reached on the specified slope of the input signal The LEVEL trigger event or sample event can only be used for DC voltage or direct sampled measurements 2 The output buffer must be empty and reading memory must be OFF or empty for the SYN event to occur 3 The input buffer must be enabled or you must suppress cr If when sending the TARM SGL command Chapter 4 Making Measurements 91 Reading Formats This section discusses the ASCH single integer SINT double integer DINT single real SREAL and double real DREAL formats that can be used for storing readings or for outputting readings on the GPIB Storing readings in memory is described later in this chapter under Using Reading Memory outputting readings on the GPIB is discussed later in this chapter under Sending Readings Across the Bus ASCII The ASCII format is 15 bytes per reading encoded in scientific notation in standard units of volts amps ohms hertz or seconds as follows SD DDDDDDDDESDD Where S sign or D 0 9 E delimiter between mantissa and base 10 exponent Single
272. en per sample event if the sample event is AUTO readings are taken continuously AUTO EXT AUTO EXT TIMER After a negative edge transition on the Ext Trig input one LINE LEVEL reading is taken per sample event until the specified number of readings are completed AUTO EXT SYN Illegal AUTO LEVEL AUTO EXT TIMER After the LEVEL event occurs one reading is taken per LEVEL sample event until the specified number of readings are completed AUTO LEVEL SYN LINE Illegal AUTO LINE AUTO EXT TIMER After the power line voltage crosses zero volts one reading is LINE taken per sample event until the specified number of readings are completed AUTO LINE SYN LEVEL Illegal AUTO SGL Any After executing the TRIG SGL command one reading is taken per sample event until the specified number of readings are completed The trigger event then becomes HOLD When using the SYN sample event the input buffer must be enabled or you must suppress cr If when sending the TRIG SGL command AUTO SYN SYN After the controller requests data 2 both SYN events are satisfied and the first reading is taken One reading is then taken per SYN event until the specified number of readings are completed AUTO SYN AUTO EXT LEVEL After the controller requests data one reading is taken per LINE TIMER sample event until the specified number of readings are completed EXT AUTO Any After a negative edge transition on the Ext Trig input one reading
273. en you suppress cr lf Trigger Buffer Enables or disables the multimeter s external trigger buffer TBUFF control control The control parameter choices are Numeric control Query Parameter Equiv Description OFF 0 Disables the trigger buffer which enables the TRIGGER TOO FAST error ON 1 Enables and clears the trigger buffer which disables the TRIGGER TOO FAST error Power on control OFF Default control OFF Setting TBUFF to ON corrects fora TRIGGER TOO FAST error that can occur when using an external EXT trigger arm trigger or sample event With TBUFF OFF any external trigger occurring during a reading generates the TRIGGER TOO FAST error and the trigger s are ignored With TBUFF ON the first external trigger occurring during a reading is stored and no error is generated by this or any successive triggers After the reading is complete the stored trigger satisfies the EXT event if the multimeter is so programmed Executing the RESET command sets TBUFF to OFF Query Command The TBUFF query command returns the present trigger buffering mode Refer to Query Commands near the front of this chapter for more information Related Commands EXTOUT NRDGS TRIG OUTPUT 722 TBUFF ON DISABLES THE TRIGGER TOO FAST ERROR Chapter 6 Command Reference 253 TEMP TEMP TERM Syntax Remarks Example Syntax Remarks Temperature Query Returns the multimeter s internal temperature in degree
274. ends readings by setting the trigger arm event to HOLD The configuration is changed lines 30 50 and line 60 initiates a single reading which is transferred to the controller and displayed After the single reading the trigger arm event becomes HOLD which suspends readings 10 OUTPUT 722 RESET RESET ALL TRIGGERING EVENTS AUTO 20 OUTPUT 722 TARM HOLD SUSPEND READINGS 30 OUTPUT 7227 DCV TOY DC VOLTAGE 10V RANGE 40 OUTPUT 722 NPLC 1 1 PLC INTEGRATION TIME 50 OUTPUT 722 AZERO OFF AUTOZERO OFF 60 OUTPUT 722 TARM SGL TRIGGER 1 READING 70 ENTER 722 A ENTER READING 80 PRINT A PRINT READING 90 END In the PRESET NORM state readings are suspended because the trigger event is set to SYN the SYN event is discussed later in this chapter In this state you can initiate a single reading using the TRIG SGL command For example in the following program line 10 suspends readings by setting the trigger event to SYN Line 20 initiates a single reading and the reading is transferred to the controller and displayed Following execution ofthe TRIG SGL command the trigger event becomes HOLD which suspends readings 10 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN NRDGS 1 AUTO 20 OUTPUT 722 TRIG SGL GENERATE SINGLE TRIGGER 30 ENTER 722 A ENTER READING 40 PRINT A PRINT READING 50 END Making Multiple You can use the NRDGS command to specify more than one reading per trigger event For example the following program t
275. enheit gt of 100Q RTD with alpha of 0 003916 The following example performs a temperature measurement using a 10kQ thermistor and returns the result in degrees Celsius 10 OUTPUT 722 PRESET NORM READINGS 20 OUTPUT 722 OHMF 10E3 PRESETS MULTIMETER SUSPENDS SELECTS 4 WIRE OHMS 10kQ RANGE 30 OUTPUT 722 MATH CTHRM10K CELSIUS CONVERSION 10kQ THERMISTOR 40 OUTPUT 722 TRIG SGL 50 ENTER 722 A 60 PRINT A 70 END Chapter 4 Making Measurements TRIGGER READING ENTER RESULT PRINT RESULT w ps Chapter 5 Digitizing Tintro duction eccisccsaccensednaercocsacenneeaccuvenncesneentesiee 129 Digitizing Methods cceceeseeceeeseeseeeeeeeensees 129 The Sampling Rate ccc eccescceeseeseeeseeeteeeeees 131 Level Triggering sencers riai i 132 Level Triggering Examples sesseeseeeeeeeeeseeee 132 Level Filtering iera Tean e 134 DCV Digitizing cececcecseesseeteceteceseeeeeeneeesaes 134 DOV Remarks enaren araa aaa das 135 DEV Example nteress 136 Direct Sampling ccceccccseesseeeeceesceseeeseeeeenseens 137 Direct Sampling Remarks eeeeeeeeeeneees 138 Direct Sampling Example ssseeeseeeeeeeeeee 139 Sub Sampling seepia is niais 139 Sub Sampling Fundamentals cceeeee 140 The Sync Source Event 2 0 ceceeceeseeeteereees 141 Sub Sampling Remarks 0 0 ceceecceseeeterees 143 Sending Samples to Memory ccceeeeeeee 144 Sending Samples to the Cont
276. ensated quartz crystal has its drift and jitter which will affect the amplitude measurement of the input signal But these tend to be very small less than 50 ps Hence the clock accuracy and jitter do not really affect the measurement within the measurement bandwidth of the 3458A The timebase jitter error is not cumulative therefore each sample point has only its own jitter error and not the combined jitters of previous sample points The effects of all the time axis errors are shown in Figure 64 Appendix E High Resolution Digitizing With the 3458A 361 362 The trigger error is orders of magnitude greater than timebase error and jitter Two effects cause this The 3458A has no delay line so there is a trigger latency a time delay between the trigger and the commencement of the measurement that is fixed by the firmware the clock and the timing circuits It is specified to be less than 175 ns for an external trigger The accuracy of the trigger can also be affected by noise on the trigger signal and time interpolator variation between measurements This is of the order of 50 ps as well except in very noisy cases where it is advisable to use the 3458A s trigger filter which reduces the bandwidth of the trigger circuit to a nominal value of 70 kHz Figure 64 The effects of timebase jitter is shown here For the 3458A Multimeter the jitter is 50ps RMS This jitter is repeatable so it can be characterized and corrected Normaliz
277. ensation enabled the multimeter measures the external offset voltage with the ohms current source shut off before each resistance reading and subtracts the offset from the following reading This prevents the offset voltage from affecting the resistance reading but it doubles the time required per reading You can use offset compensated ohms on both 2 wire and 4 wire resistance measurements When you have offset compensation enabled and change from ohms to some other measurement function DCV ACV etc offset compensation is temporarily disabled When you return to 2 wire or 4 wire ohms however offset compensation is once again enabled The multimeter can only perform offset compensation on the 10Q through100kQ ranges If OCOMP is enabled when using the IMQ through 1GQ ranges readings are made without offset compensation Query Command The OCOMP query command returns the present offset compensation mode Refer to Query Commands near the front of this chapter for more information Related Commands OHM OHMF Example OUTPUT 722 OCOMP ON ENABLES OFFSET COMPENSATION Chapter 6 Command Reference 209 OFORMAT OFORMAT Output Format Designates the GPIB output format for readings sent directly to the controller or transferred from reading memory to the controller Syntax OFORMAT format format The format parameter choices are Numeric format Query Parameter Equiv Descriptions ASCII 1 ASCII 15 bytes per readin
278. ent occurs 15 times COMPUTER ARRAY NUMBERING STARTS AT 1 DIMENSION ARRAY FOR 15 READINGS OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE OUTPUT 722 NRDGS 15 SYN 15 READINGS PER TRIGGER SYN SAMPLE EVENT OUTPUT 722 TRIG AUTO AUTO TRIGGER EVENT ENTER 722 Rdgs SYN EVENT ENTER EACH READING DISP Rdgs PRINT READINGS END Making Timed When making multiple readings per trigger you can use the TIMER sample Readin gs event to place a specified time interval between readings This interval is the amount of time from the beginning of one reading to the beginning of the nextreading You specify the interval in seconds using the TIMER command If the specified interval is less than the time required to make each reading the multimeter generates the TRIG TOO FAST error The following program specifies 8 readings per trigger with 1 second between readings this is shown in Figure 18 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 8 DIMENSION ARRAY FOR 8 READINGS 30 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 NRDGS 8 TIMER 8 READINGS TRIGGER TIMER SAMPLE EVENT 50 OUTPUT 722 TIMER 1 1 SECOND TIMER INTERVAL 60 ENTER 722 Rdgs SYN EVENT ENTER EACH READING 70 PRINT Rdgs PRINT READINGS 80 END You can also use the SWEEP command to replace the NRDGS n TIMER command and the TIMER command The SWEEP command s first parameter specifies th
279. ents RMS Note Measuring Temperature For example using the first equation if the reading rate is 200Hz and the DEGREE is 20 the time constant is t 25 l I 0 092 Seconds Using the second equation with the same reading rate and DEGREE produces t 1 200 x 20 0 1 seconds The RMS math operation can be used to compute the combined RMS value of the AC and DC components of digitized using the DCV DSAC or DSDC command low frequency signals For repetitive AC signals of 1 Hz or greater the synchronous AC measurement method can be used instead of the RMS math operation If the AC signal is 10Hz or greater the analog AC method can be used If the signal is 20Hz or greater the random method can be used You can also determine the RMS value of the AC component of sinewaves by digitizing using the DCV DSAC or DSDC command and enabling the STATS math operation After a number of readings the result in the SDEV register is the RMS value of the AC component of the input signal The RMS math operation takes the square root of the preceding FILTER operation with the reading and the previous result first squared The RMS math equation is Result PreviousResul e DEGREE 1 Reading DEGREE DEGREE Where Previous Result is initially set to the value of the first reading and thereafter is set to the result of this FILTER operation Reading is the latest reading taken DEGREE selects the step res
280. ents of the input signal Figure 30 shows 20 samples made using direct sampling on a sine wave input the numbers indicate the order in which the samples were taken With direct Chapter 5 Digitizing 137 138 Direct Sampling Remarks Chapter 5 Digitizing sampling the minimum possible interval between samples is 20us 7 4 1516 Figure 30 Direct sampling e You cannot use autorange for direct sampled measurements you must specify the range as the first parameter of the DSAC or DSDC command max input parameter The max input parameters and the ranges they select are Full Scale max _input Parameter Selects Range SINT Format DINT Format 0 to 012 10mV 12mV 50mv gt 012 to 120 100mV 120mV 500mV gt 120 to 1 2 1V 1 2V 5 0V gt 1 2 to 12 10V 12V 50V gt 12 to 120 100V 120V 500V gt 120 to 1E3 1000V 1050V 1050V Notice that when using the DINT memory output format the full scale values for direct sampling are 500 5 times the ranges of 10mV 100mV 1V 10V and 100V This is particularly important to consider when specifying the percentage for level triggering When specifying the level triggering voltage use a percentage of the range For example assume the input signal has a peak value of 20V and you are using the 10V range If you want to level trigger at 15V specify a level triggering percentage of 150 LEVEL 150 command The slew rate of the multimeter s amplifiers may b
281. equency rounded to 50 TBUFF OFF or 60Hz TIMER 1 LOCK OFF TRIG AUTO MATH OFF MEM OFF last memory operation set to FIFO ALL math registers set to 0 except DEGREE 20 REF 1 SCALE 1 RES 50 PERC 1 e Although RESET can be used from remote it is intended primarily for front panel use RESET configures the multimeter to a good starting point for local operation Executing the RESET command from the alphabetic menu resets the multimeter as shown above Pressing the shifted front panel Reset key however has the same effect as cycling the multimeter s power This stores the present state as state 0 any compressed subprograms are destroyed stored readings are destroyed the power on SRQ bit is set in the status register and the power on sequence is performed e When attempting to send the RESET command from remote it is possible that the multimeter is busy or the GPIB bus is being held In either case the multimeter will not respond immediately to the remote RESET command For this reason you should send the GPIB device clear command before you send the multimeter s RESET command This is shown in the example below Related Commands PRESET 10 CLEAR 722 CLEARS THE MULTIMETER IMMEDIATELY 20 OUTPUT 722 RESET RESETS THE MULTIMETER Chapter 6 Command Reference 227 REV 30 END REV Revision Query Returns two numbers separated by a comma The first number is the multimeter s master processor firmware revis
282. er arm and trigger events have already occurred the multimeter makes a reading The multimeter will then make one reading per sample event until the specified number of readings are taken The first parameter of the NRDGS number of readings command specifies how many readings are to be taken per trigger event The second parameter specifies the event sample event that initiates each reading You can select from a variety of events to use as the trigger arm trigger and sample events Table 20 describes the event parameters and shows the commands to which they apply Table 20 Event Parameters Event Used With Used With Parameter TARM TRIG NRDGS Event Description AUTO Occurs automatically whenever required EXT Occurs on negative edge transition on the multimeter s external trigger input HOLD Suspends measurements LEVEL 1 Occurs when the specified voltage is reached on the specified slope of the input signal LINE 2 Occurs when the power line voltage crosses zero volts SGL Occurs once upon receipt of TARM SGL or TRIG SGL command then becomes HOLD SYN Occurs when the multimeter s output buffer is empty reading memory is off or empty and the controller requests data TIMER 2 Occurs automatically with a time interval between readings 1 The LEVEL trigger or sample event can be used only for DC voltage or direct sampled digitizing
283. er event All math registers set to 0 except DEGREE 20 PERC 1 REF 1 RES 50 SCALE 1 When attempting to preset from remote it is possible that the multimeter is busy or the GPIB interface is being held In either case the multimeter will not respond to aremote command It s good practice to send the GPIB Device Clear command prior to presetting the multimeter The multimeter responds immediately to the Device Clear command The following program sends the Device Clear command followed by the PRESET NORM command 10 CLEAR 722 20 OUTPUT 722 PRESET NORM 52 Chapter 3 Configuring for Measurements Specifying a Measurement Function Autorange 30 END In addition to the PRESET NORM command the multimeter has a PRESET FAST command configures for fast readings and transfers which is discussed in Chapter 4 and a PRESET DIG command configures for DCV digitizing which is discussed in Chapter 5 The first parameter of the FUNC command selects the measurement function For example to specify DC voltage measurements send OUTPUT 722 FUNC DCV The FUNC command header is optional and can be omitted For example you can specify DC voltage measurements simply by sending OUTPUT 722 DCV The remaining examples in this chapter use the shortened no FUNC header version Table 11 shows the various measurement function parameters and the function selec
284. eric mode Query Parameter Equiv Description OFF 0 Enables protection syntax amp error algorithms ON 1 Disables protection syntax amp error algorithms Power on mode OFF Default mode OFF Remarks Caution DEFEAT ON must only be used when you are certain that overload voltages on the Input terminals will not exceed 100V peak on the 10V range or below On the 100V and 1000V ranges the multimeter can withstand voltages up to 1200V peak regardless of whether DEFEAT is ON or OFF DEFEAT ON disables defeats the input switch sequencing that protects the multimeter s input circuitry from overload voltages If input protection is disabled and an overload situation is detected on the 10V range or below the multimeter will enable input protection and internally tally the overload for instrument warranty considerations Since DEFEAT ON disables certain syntax checking and error reporting algorithms it should be used only after all system programming is complete and operational Query Command The DEFEAT query command returns the present DEFEAT mode Refer to Query Commands near the front of this chapter for more information 168 Chapter 6 Command Reference DEFKEY Example Syntax number string Remarks DEFKEY OUTPUT 722 DEFEAT ON DISABLES PROTECTION SYNTAX amp ERROR ALGORITHMS Define Key Allows you to assign one or more commands to a particular user defined function key on the front pa
285. es arms the trigger event TRIG command You can also use this command to perform multiple measurement cycles TARM event number_arms event The event parameter choices are Numeric event Query Parameter Equiv Description AUTO 1 Always armed EXT 2 Arms following a low going TTL transition on the Ext Trig connector Executing TARM EXT clears the trigger buffer if TBUFF is ON SGL 3 Arms once upon receipt of TARM SGL then becomes HOLD HOLD 4 Triggering is disabled SYN 5 Arms when the multimeter s output buffer is empty reading memory is off or empty and the controller requests data Power on event AUTO Default event AUTO number_arms The number_arms parameter is valid only with the SGL trigger arm event in this case the valid range is 0 2 1E 9 Specifying 0 or 1 with the SGL event has the same effect as using the default value 1 the triggeris armed once and then reverts to the HOLD state disabled When you specify a number greater than 1 as the number_arms parameter you have selected multiple arming In multiple arming the multimeter generates enough single trigger arms to satisfy the number_arms parameter Refer to multiple arming in the Remarks section below for more information Power on number_arms multiple arming disabled Chapter 6 Command Reference 251 TARM 252 Remarks Examples Default number_arms 1 multiple arming disabled e For all measurement func
286. ess speed for more resolution Even the traditionally slower measurement functions such as AC Volts are quicker with the 3458A For example you can measure true rms ACV at up to 50 readings per second with full accuracy for input frequencies greater than 10 kHz That a multimeter s increased reading rate results in increased test throughput is clear Not as obvious but strongly affecting throughput as well is the operating speed of the multimeter when changing function range reading speed integration time or interfacing mode The 3458A can change function and range take a measurement and output the result at 200 per second Attempts to make measurement more application oriented and less hardware dependent resulted in advances in the command language of multimeters that often yielded easier more friendly programming However these advances also required increased overhead and slower response to the command language The 3458A Multimeter has been specifically designed to overcome this problem by offering fast command response with an application oriented command language that is also easy to use It is well known that some measurements are inherently not amenable to fast treatment Examples of these are high impedance measurements frequency measurements of low frequency events root mean square rms AC voltage and current measurements and accurate measurements in the presence of noise Nonetheless despite their inherent slowness substa
287. est number possible for the particular output format as follows SINT format 32767 or 32768 unscaled DINT format 2 147483647E 9 or 2 147483648E 9 unscaled ASCII SREAL DREAL 1 0E 38 Each reading output to the GPIB in ASCII format is normally followed by cr If carriage return line feed The cr f indicates the end of transmission to most controllers Readings output in any other format do not have the cr If end of line sequence With any output format you can enable the GPIB EOI End Or Identify function to mark the end of transmission Refer to the END command in Chapter 6 for more information The ISCALE command returns the scale factor in ASCII format for readings output in the SINT or DINT format After the controller retrieves the scale factor the output format returns to the specified SINT or DINT format You can retrieve the scale factor after the multimeter is configured but before readings are triggered or after all readings are completed and transferred to the controller If a reading is in the output buffer when the ISCALE command is executed the reading will be overwritten by the scale factor The following program outputs 10 readings in SINT format retrieves the scale factor and multiplies the scale factor times each reading The readings are transfcrred to the controller using the TRANSFER statement this Chapter 4 Making Measurements 99 100 command is specific to Hewlett Packard 200 300 contro
288. eter to take readings at its maximum rate of gt 100k readings per second Readings are output using the SINT format Ifthe bus controller cannot transfer readings at gt 200k bytes per second the reading rate will be slower This is because in the high speed mode the multimeter waits until each reading is removed from its output buffer before placing the next reading in the output buffer In the following program the SYN trigger arm event is used to trigger the readings TRIG SYN could also be used The SYN event is very important for high speed operation since it ensures the controller will be ready to accept the first reading output by the multimeter The TRANSFER statement line 120 satisfies the SYN event and is the fastest way to transfer readings across the GPIB especially when used with the direct memory access DMA GPIB interface COMPUTER ARRAY NUMBERING STARTS AT 1 20 30 40 50 60 INTEGER Num_readings INTEGER Int_rdgs 1 30000 REAL Rdgs 1 30000 Num_readings 30000 ASSIGN Dvm TO 722 BUFFER DECLARE VARIABLE CREATE INTEGER ARRAY FOR BUFFER CREATE REAL ARRAY NUMBER OF READINGS 30000 ASSIGN MULTIMETER ADDRESS 70 ASSIGN Int_rdgs TO BUFFER Int_rdgs PRESET FAST 90 OUTPUT Dvm APER 1 4E 6 80 OUTPUT Dvm 100 OUTPUT Dvm 110 OUTPUT Dvm 115 130 OUTPUT Dvm 140 ENTER Dvm S 210 NEXT I 220 END High Speed Transfer 108 from Memory 120 TRANSFER Dvm TO Int rdgs WAIT
289. etween successive readings specify interval with the TIMER command LEVEL 7 Initiates reading when the input signal reaches the voltage specified by the LEVEL command on the slope specified by the SLOPE command LINE 8 Initiates reading on a zero crossing of the AC line voltage The TIMER or LINE event cannot be used for sampled AC or AC DC voltage measurements SETACV RNDM or SYNC or for frequency or period measurements The LEVEL sample event can be used only for DC voltage and direct sampled measurements Power on event AUTO Default event AUTO Remarks Since the TIMER event designates an interval between readings it only applies when count is greater than one The first reading occurs without the TIMER interval However you can insert a time interval before the first reading with the DELAY command The TIMER event suspends autoranging You can use the SWEEP command to replace the two commands NRDGS n TIMER and TIMER n The SWEEP command specifies the number of readings and the interval between readings These commands are interchangeable the multimeter uses whichever command was executed last in the programming Executing the SWEEP command automatically sets the sample event to TIMER In the power on RESET and PRESET states the multimeter uses the NRDGS command e When SYN is used for more than one of the trigger arm trigger or sample Chapter 6 Command Reference 207 NRDGS 208 Examples events
290. external trigger signal that occurs during a rending generates the TRIGGER TOO FAST error and the trigger s are ignored With trigger buffering enabled the first external trigger that occurs during a reading is stored and no error is generated by this or any successive triggers After the reading is complete the stored trigger satisfies the EXT event if the multimeter is so programmed Trigger buffering is useful when you are using an external scanning device synchronized to the multimeter s EXTOUT signal using the input complete ICOMP event Since the ICOMP pulse occurs before each reading is finished it is possible for the scanner to close the next channel and generate its channel closed pulse which is used to trigger the multimeter before the reading is complete Refer to Input Complete later in this chapter for more information In the multimeter s power on state trigger buffering is disabled To enable trigger buffering send OUTPUT 722 TBUFF ON To disable trigger buffering send OUTPUT 722 TBUFF OFF You can specify many combinations of the trigger arm trigger and sample events to suit your application Table 21 shows all possible combinations of these events and describes the resultant triggering sequence for each 88 Chapter 4 Making Measurements Table 21 Event Combinations Trigger Arm Trigger Sample Description Event Event Event AUTO AUTO Any One reading is tak
291. f the program is changed Now the sequence of measurements with all of the variations imposed up to this point on each measurement is placed in a dmm subprogram SUB 1 The commands are transferred from the computer to the 3458A where they are compiled Execution of the commands commence when the dmm subprogram is called with the CALL 1 command The readings are transferred when the dmm subprogram is complete Note that the program halted while the dmm is completing this sequence If continued program operation were wanted the output statement to the dmm would Appendix D Optimizing Throughout and Reading Rate be OUTPUT 722 USING K CALL 1 By using the image K the End Of Line EOL terminators are suppressed When the 3458A receives the command without a terminator it releases the computer so that the computer can continue the program while the 3458A continues with the operations it was requested to do Note that the execution time for the benchmark is markedly less than just using Reading Memory Display Off Subprogram Display test execution time 500 s program memory download time 280 s reading transfer time 180 s 2250 SUB Disp REAL Dnld_time Exe time Tns_ time 2260 DIM A 37 2270 Dnld_time TIMEDATE 2280 OUTPUT 722 PRESET MFORMAT SREAL DISP OFF TESTING 2290 OUTPUT 722 SUB 1 MEM FIFO OHM 1E4 NPLC 0 DELAY 0 NRDGS 15 TRIG SGL 2300 OUTPUT 722 0HM 1E5 NRDGS 8 TRIG SGL 2310 OUTPUT 722 OHMF 1E3 APER 20E
292. fective ORD shown represent ou a eS samples acquired in one period of the input Sequential sampling Choice of Two Measurement Paths Using the DCV Path for Direct Sampling The 3458A provides two different input measurement paths the standard DCV path and the track and hold path see Figure 52 The track and hold path is used for subsampling and direct sampling The DCV path is used for direct sampling alone At your discretion you may use the standard DCV path for subsampling but you have to program the algorithm for data capture The standard DCV path is selected for you when you program the command PRESET DIG This command establishes default parameters to directly digitize the input signal assuming that you will want 256 samples at 50 kSamples s with full scale set at 10 V peak The trigger circuit assumes that you want to trigger on the input signal at 0 V level positive slope AC coupled Hence with these default conditions you can capture at least one cycle from 200 Hz up to 25 kHz The standard DCV path also offers speed and resolution tradeoffs from 18 bits 5 1 2 digits at 6 kSamples s to 16 bits 4 1 2 digits at 100 kSamples s The noise floor on the 10 V range for the corresponding sample rates are 0 005 and 0 05 respectively As the resolution is increased in the DCV path there is a corresponding increase in the aperture time Hence the obvious trade off for lower noise and more resolution is the loss of
293. ficient ppm Resolution Sones Voltage Circuit Lead Series Offset of Reading ppm of Range C Resistance OCOMP OHMF ON Without With ACAL ACAL 10Q 12 00000 10 uQ 10mA O1V 12V 209 0 01 V 3 1 1 1 100 Q 120 00000 10 nQ 1mA O1V 12V 200 Q 0 01 V 3 1 1 1 1kQ 1 2000000 100 uQ 1 mA 10V 12V 150 Q 0 1 V 3 0 1 1 0 1 10 KQ 12 000000 1mQ 100 uA 10V 12V 1 5 KQ 0 1 V 3 0 1 1 0 1 100kQ 120 00000 10mQ 50 pA 50V 12V 1 5 KQ 0 5 V 3 0 1 1 0 1 1 MQ 1 2000000 100 mQ 5 pA 50V 12V 1 5 KQ 3 1 1 1 10 MQ 12 000000 1Q 500nA 50V 12V 1 5 KQ 20 20 5 2 100 MQ 120 00000 102 500nA 50V 5V 1 5 KQ 100 20 25 2 1 GQ7 1 2000000 100 Q9 500nA 50V 5V 1 5 KQ 1000 20 250 2 6 Current source is 3 absolute accuracy 7 Additional error from Tcal or last ACAL 1 C 8 Additional error from Tcal S amp C 9 Measurement is computed from 10 M Q in parallel with input Appendix A Specifications 285 2 Accuracy ppm of Reading ppm of Range Range 24 Hour 90 Day 109 543 1515 100 Q 3 3 10 5 1kQ 2 0 2 8 0 5 10 kQ 2 0 2 8 0 5 100 kQ 2 0 2 8 0 5 1MQ 10 1 12 2 10 MQ 50 5 50 10 100 MQ 500 10 500 10 1GQ 0 5 10 0 5 10 1 Year 2 Year 15 5 20410 1 Specifications are for PRESET 1245 20 10 NPLC 100 OCOMP ON OHMF 10 0 5 15 1 2 Tcal 1 C 10 0 5 15 1 3 Specifications for 90 day 1 year 10 0 5 15 1 and 2 year are within 24 hours and 15 2 20 4 1 C of last ACAL Tcal 5 C 50 10 75 10 Add 3 ppm of reading additiona
294. filter Refer to the LFILTER command in Chapter 6 for details The ACBAND command specifies the frequency content of the input signal for all AC and AC DC measurements Specifying the frequency content allows the multimeter to make accurate measurements and to configure itself for the fastest possible measurements The ACBAND command s first parameter specifies the lowest expected frequency component the power on PRESET NORM value is 20Hz The second parameter specifies the highest expected frequency component the power on PRESET NORM value is 2MHz For example suppose the input signal has a frequency range of 750 Hz to 2 kHz you should send OUTPUT 722 ACBAND 750 2000 Refer to the Specifications in Appendix A for accuracy specifications and reading rate specifications for analog AC measurements based on the frequency components of the input signal For synchronous AC or AC DC voltage measurements the bandwidth parameters are used by the multimeter to calculate time out values and sampling parameters For frequency or period measurements with autorange enabled the bandwidth parameters are used to determine the amount of time needed for autoranging For these measurements it is very 66 Chapter 3 Configuring for Measurements Setting the Integration Time Note Note important that the specified bandwidth particularly the specified low frequency corresponds to the frequency content of the input signal Integra
295. for more information You specify AC current measurements using the ACI command or AC DC current measurements using the ACDCI command For example to specify AC current measurements on the 100uA range send OUTPUT 722 ACI 100E 6 To specify AC DC current measurements on the 10mA range send OUTPUT 722 ACDCI 10E 3 Table 16 AC and AC DC Current Ranges and Resolution ACI Range Full Scale Reading Maximum Resolution Shunt Resistor l00uA 120 0000HA IOOpA 7300 1mA 1 200000mA 1nA 100Q 10mA 12 00000mA 10nA 10Q 100mA 120 0000mA 100nA 10 1A 1 050000A 1pA 0 19 Frequency or Period The multimeter s frequency and period counter accepts AC voltage or AC current inputs The maximum resolution is 7 digits for both frequency and period measurements Refer to Specifying Resolution later in this section for more information You specify frequency measurements using the FREQ command or period measurements using the PER command For frequency or period measurements you must also specify whether the input signal is from a voltage source or a current source and whether the measurements will be AC or DC coupled This is done using the FFOURCE command the power on default value is ACV Table 17 shows the FSOURCE parameters the type of input specified by each and the measurement capabilities of each The terminal connections for frequency or period measurements from a voltage source are shown in Figure 11 The termin
296. from the multimeter The following program uses the ENTER statement to transfer readings to the computer using the DREAL format The ENTER statement is eas ier to use since no I O path is necessary but is much slower than the TRANSFER statement Also when using the ENTER statement you must use the FORMAT OFF command to instruct the controller to use its internal data structure instead of ASCII 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 20 Num_readings 20 NUMBER OF READINGS 20 30 ALLOCATE REAL Rdgs 1 Num_readings CREATE ARRAY FOR READINGS 40 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 50 OUTPUT Dvm PRESET NORM OFORMAT DREAL NPLC 10 NRDGS Num_readings 55 TRIG SYN DCV AUTORANGE DREAL OUTPUT FORMAT 10 PLC 20 READINGS TRIG 60 ASSIGN Dvm FORMAT OFF USE 8 BYTE WORD DATA STRUCTURE 70 FOR I 1 TO Num_readings 80 ENTER Dvm Rdgs I ENTER EACH READING 90 IF ABS Rdgs I 1 E 38 THEN IF OVERLOAD OCCURRED 00 PRINT OVERLOAD OCCURRED PRINT OVERLOAD MESSAGE 10 ELSE IF NO OVERLOAD OCCURRED 20 Rdgs I DROUND Rdgs I 8 ROUND READINGS TO 8 DIGITS 30 PRINT Rdgs I PRINT READINGS 40 END IF 50 NEXT I 60 END OHM OHMF Refer to the FUNC command OPT Option Query Returns a response indicating the multimeter s installed options The possible responses are 0 No installed options 1 Extended Reading Memory Option Syntax OPT Remarks Related Commands QFORMAT Example 10 ov
297. full scale to 10 of full scale DC lt 10 of AC sine wave input crest factor 1 4 and PRESET Within 24 hours and Range Full Scale Maximum Input Impedance of Reading of Range C 1 C of last ACAL Lo to Resolution Guard Switch on 10mV 12 00000 10 nV 1 MO 15 with lt 140pF 0 003 0 02 Peak AC DC input limited 100 mV 120 00000 10 nV 1 MQ 15 with lt 140pF 0 0025 0 00012 to 5 x full scale for all ranges in 1V 1 2000000 100 nV 1 MQO 15 with lt 140pF 0 0025 0 0001 ACV function 10 V 12 000000 l uV 1 MQ 2 with lt 140pF 0 0025 0 0001 Add 2 ppm of reading 100 V 120 00000 10 uV 1 MQ 2 with lt 140pF 0 0025 0 0001 additional Srror for Keysight 1000 V 700 0000 100 uV 1 MQ 2 with lt 140pF 0 0025 0 0001 factory traceability of 10 V DC to US NIST AC Accu racy LFILTER ON recommended 24 Hour to 2 Year of Reading of Range ACBAND lt 2 MHz 1 Hz to 40 Hz to 1 kHz to 20 kHz to 50 kHz to 100 kHzto 300kHzto 1MHzto Range 40 Hz 1 kHz 20 kHz 50 kHz 100 kHz 300 kHz 1 MHz 2 MHz 10 mV 0 03 0 03 0 02 0 011 0 03 0 011 0 1 0 011 0 5 0 011 4 0 0 02 100 mV 10 V 0 007 0 004 0 007 0 002 0 014 0 002 0 03 0 002 0 08 0 002 0 3 0 01 1 0 01 1 5 0 01 100 V 0 02 0 004 0 02 0 002 0 02 0 002 0 035 0 002 0 12 0 002 0 4 0 01 1 5 0 01 1000 V 0 04 0 004 0 04 0 002 0 06 0 002 0 12 0 002 0 3 0 002 288 Appendix A Specifications AC Accuracy continued 24 Hour to 2 Year of Reading
298. g see Ist amp 2nd Remarks below SINT 2 Single Integer 16 bits 2 s complement 2 bytes per reading DINT 3 Double Integer 32 bits 2 s complement 4 bytes per reading SREAL 4 Single Real IEEE 754 32 bits 4 bytes per reading DREAL 5 Double Real IEEE 754 64 bits 8 bytes per reading Power on format ASCII Default format ASCII Remarks The ASCII output format sends the cr If carriage return line feed to indicate the end of the transmission to most computers The SINT DINT SREAL and DREAL output formats however do not send cr If With any format you can use the END command to indicate the end of the transmission using the GPIB EOI function Refer to the END command for more information e When using the ASCII format 2 additional bytes are required for the carriage return line feed cr f end of line sequence The cr fis used only for the ASCII format and normally follows each reading output in ASCII format However when using the ASCII output format and multiple readings are recalled from reading memory using the RMEM command the multimeter places a comma between readings comma 1 byte In this case the cr foccurs only once following the last reading in the group being recalled Commas are not used when readings are output directly to the bus reading memory disabled when readings are recalled using implied read or when using any other output format The multimeter indicates an overload conditi
299. g Measurements Using the SREAL The following program shows how to convert 10 readings output in the Output Format SREAL format 10 OPTION BASE 1 20 30 40 50 60 INTEGER Num_readings Num_readings 10 ALLOCATE REAL Rdgs 1 Num_readings ASSIGN Dvm TO 722 COMPUTER ARRAY NUMBERING STARTS AT 1 DECLARE VARIABLE NUMBER OF READINGS 10 CREATE ARRAY FOR READINGS ASSIGN MULTIMETER ADDRESS ASSIGN Buffer TO BUFFER 4 Num_readings ASSIGN BUFFER I O PATH NAME 70 OUTPUT Dvm PRESET NORM OFORMAT SREAL NRDGS Num_readings 15 80 90 TRANSFER Dvm TO Buffer WAIT FOR I 1 TO Num_readings 100ENTER Buffer USING B A B C D 101 EACH VARIABLE STATEMENT TERMINATION NOT REQUIRED B ENTER ONE 105 8 BIT BYTE AND INTERPRET AS AN INTEGER BETWEEN 0 AND 255 110S 1 120IF A gt 127 THEN S 1 130IF A gt 127 THEN A A 128 140A A 2 127 150IF B gt 127 THEN A A 1 160IF B lt 127 THEN B B 128 170Rdgs I S B 65536 C 256 D 2 A 23 CONVERT READING FROM SREAL 180Rdgs I DROUND Rdgs I 7 181 MUST DO THIS WITH SREAL TO ENSURE ANY OVLD VALUES ARE ROUNDED TO 185 1 E 38 WITHOUT ROUNDING THE VALUE MAY BE SLIGHTLY LESS 190IF ABS Rdgs I 1 E 38 THEN 200PRINT Overload Occurred 210ELSE 220PRINT Rdgs I 230END IF 240NEXT I 250END Using the DREAL Output Format 10 OPTION BASE 1 20 REAL Rdgs 1 10 BUFFER 30 ASSIGN Dvm TO 722 40 ASSIGN Rdgs TO BUFFER Rdgs 50 55 6
300. g QFORMAT REMOTE EXTOUT SPOLL LEVEL Errors TRIGGER LFILTER AUXERR NRDGS EMASK SLOPE ERR SSRC ERRSTR Chapter 6 Command Reference 155 Commands vs Measurement Functions Commands vs Measurement Functions Table 6 1 shows the multimeter commands that apply only to certain measurement functions A bullet e indicates the command applies with no restrictions A number 1 5 indicates the command applies with qualifications see numbered footnotes below the table A blank indicates the command is not applicable to the measurement function The remaining multimeter commands not shown in Table 6 1 apply to all measurement functions with no restrictions Table 28 Commands vs Measurement Functions Dev De OHM Acv Acv ACV ACI FREQ DSAC SSAC OHMF ACDCV ACDCV ACDCV ACDCI PER DSDC SSDC ANA SYNC RNDM ACBAND APER e e ARANGE e e e e e AZERO e FIXEDZ FSOURCE ISCALE e e e 1 LEVEL 2 3 LFILTER e LFREQ e 6 7 M MATH e e e e e e e e e 4 MFEORMAT e e e e 1 e NPLC e e OCOMP e OFORMAT e e e e e 1 5 RATIO SETACV SLOPE e 2 3 SSPARM SSRC SWEEP e e e e TIMER e e e 1 You should not use the SINT or DINT output memory for
301. he amplitude of the input signal Refer to Chapter 5 for details DC ohms and analog AC measurements The specified integration time and or resolution have a major effect on the reading rate for DC voltage DC current 2 wire or 4 wire ohms AC or AC DC current and AC or AC DC voltage using the SETACV ANA method only The longer the integration time or the greater the resolution the slower the reading rate The specifications in Appendix A show selected reading rates for each of these measurements based on integration time Sampled AC voltage measurements For AC or AC DC voltage measurements using SETACV SYNC or SETACV RNDM the integration time is fixed and cannot be changed For these measurements the specified resolution has a major effect on the reading rate The specifications in Appendix A show selected reading rates for sampled AC measurements based on the specified resolution Chapter 4 Making Measurements Triggering Setup Delay Time AC Bandwidth Offset Compensation High Speed DCV 10 20 25 30 40 50 60 70 High Speed OHM or OHMF Example 10 OUTPUT 722 T22 20 25 30 40 50 60 Frequency or period measurements The integration time does not affect frequency or period measurements For these measurements the specified resolution which also selects gate time has a major effect on the reading rate The specifications in Appendix A show reading rates for frequency and period measurements based o
302. he bit s with the RQS command For example suppose your application requires an interrupt when a high or low limit is exceeded bit 1 power is cycled bit 3 or when an error occurs bit 5 The decimal equivalents of these bits are 2 8 and 32 respectively The decimal sum is 42 You can enable these bits to assert SRQ by sending OUTPUT 722 ROS 42 Now whenever one of the events associated with bits 1 3 or 5 occurs it will set bit 6 in the status register and assert SRQ Notice that the bits that are not 1 Bits 4 5 and 6 are not cleared if the conditions s that set the bit s still exist Chapter 3 Configuring for Measurements 77 enabled still respond to their corresponding conditions They do not however set bit 6 or assert SRQ The following program is an example of interrupts using HP Series 200 300 BASIC HI LO LIMIT EXCEEDED ERROR POWER CYCLED INTERRUPT OUTPUT 722 PRESET NORM 30 OUTPUT 722 CSB ON INTR 7 GOTO 90 ENABLE INTR 7 2 60 OUTPUT 722 RQOS 42 MATH PFAIL SMATH MIN 5 SMATH MAX OUTPUT 722 TRIG AUTO 80 GOTO 80 OUTPUT 722 STB 100 ENTER 722 A 110 IF BINAND A 2 THEN PRINT HI LO LIMIT EXCEEDED 120 IF BINAND A 8 THEN PRINT POWER WAS CYCLED 130 IF BINAND A 32 THEN PRINT ERROR OCCURRED 140 END Line 20 presets the multimeter which suspends triggering Line 30 cle
303. he mode is set by the SETACV command OHM 4 Selects 2 wire ohms measurements OHMF 5 Selects 4 wire ohms measurements DCI 6 Selects DC current measurements ACI 1 Selects AC current measurements ACDCI 8 Selects AC DC current measurements FREQ 9 Selects frequency measurements PER 10 Selects period measurements DSAC 11 Direct sampling AC coupled DSDC 12 Direct sampling DC coupled SSAC 13 Sub sampling AC coupled SSDC 14 Sub sampling DC coupled These functions require additional explanation and are documented individually in this chapter Refer to the corresponding DSAC DSDC FREQ PER SSAC or SSDC command for details Power on function DCV Default function DCV Selects a fixed range or the autorange mode To select a fixed range you specify max _input as the absolute value no negative numbers of the input signal s maximum expected amplitude or the maximum resistance for ohms measurements The multimeter then selects the correct range Chapter 6 Command Reference 183 FUNC To select autorange specify AUTO for max _input or default the parameter In the autorange mode the multimeter samples the input signal before each reading and selects the appropriate range The following tables show the max _input parameters and the ranges they select for each measurement function For DCV max _input Selects Full Parameter Range Scale l or AUTO Autorange 0 to 12 100mV 120m
304. he multimeter is operational The self test takes approximately 50 seconds to complete To run self test send OUTPUT 722 TEST If self test passes you have a high confidence level that the multimeter is operational and assuming proper calibration that measurements will be accurate If one or more tests fail the multimeter sets bit s in the auxiliary error register which also sets bit 0 in the error register and the display s ERR 1 This chapter doesn t address digitizing specifically although most of the information under General Configuration does apply to digitizing Refer to Chapter 5 for specific information on digitizing Chapter 3 Configuring for Measurements 47 annunciator illuminates Reading the Error When a hardware error is detected the multimeter sets a bit in the auxiliary Regi sters 1 register and also sets bit 0 in the error register When a programming error is detected the multimeter sets a bit in the error register only The ERRSTR command reads each error one error at a time and then clears the corresponding bit Ifone or more bits are set in the auxiliary error register the ERRSTR command reads that register first before proceeding to the error register The ERRSTR command returns two responses The first response is the decimal value of the least significant lowest numbered set bit The second response is a message string explaining the error the maximum string length returned is 200 characte
305. he status register The following program uses the STB command to read the contents of the status register 10 OUTPUT 722 STB 20 ENTER 722 A 30 PRINT A 40 END For example assume bit 3 weight 8 and bit 7 weight 128 are set The above program returns the sum of the two weights 136 The STB command will never reveal bit 4 Ready for Instructions set because the multimeter is busy processing the STB command and therefore is not ready If you intend to monitor the ready bit you must use the GPIB Serial Poll command to read the status register If the SRQ line is true the Serial Poll command clears all status register bits The SRQ line is also returned to false if bit 6 is cleared If the SRQ line is false during Serial Poll the register s contents are not changed The following program shows how to read the status register using the Serial Poll command 10 P SPOLL 722 20 DISP P 30 END To clear the status register send OUTPUT 722 CSB When a bit of the status register is set and has been enabled to assert SRQ RQS command the multimeter sets the GPIB SRQ line true This can be used to alert the controller to interrupt its present operation and find out what service the multimeter requires Refer to your controller operating manual for information on how to program it to respond to the interrupt To allow any of the status register bits to set the SRQ line true you must first enable t
306. hether the input signal is AC voltage default AC DC voltage AC current or AC DC current using the FFOURCE command PER max _input _resolution max _input The max_input parameter selects a fixed range or the autorange mode The ranges correspond to the type of input signal specified in the FFOURCE command That is if ACV is the specified input signal the max _ input parameter specifies an AC voltage measurement range To select a fixed range you specify max _input as the absolute value no negative numbers of the expected peak value of the input signal The multimeter then selects the proper range Refer to the FUNC or RANGE command for tables showing the ranges available for each type of input signal To select the autorange mode specify AUTO for max input or default the parameter In the autorange mode the multimeter samples the input signal before each period reading and selects the proper range Power on max _input not applicable Default max _input AUTO _resolution The _ resolution parameter specifies the digits of resolution and the gate time as shown below _resolution also affects the reading rate refer to the Specifications in Appendix A for more information resolution Selects Digits of Parameter Gate Time Resolution 00001 Is 7 0001 100ms 7i 001 10ms 6 01 lms 5 l 100us 4 Chapter 6 Command Reference PRESET Remarks Example Syntax PRESET Power on _resolution not applica
307. high resolution Aliasing discussed in detail in the Digitizing Product Note 3458A 2 is avoided by a random selection of sampling intervals from 20 to 40 us in 10 ns increments With all three ACV modes of operation the user has the option of selecting accuracy versus speed if the input frequency allows Referring to Table 31 the frequency dependency of the reading rate is most pronounced for analog ACV 1 reading per second from 10 Hz to 1 kHz 10 readings per second from 1 kHz to 10 kHz and 50 readings per second from 10 kHz to 2 MHz These reading rates pertain to the specified accuracies for analog ACV The reading rates of all three modes of operation can be increased by selecting either less resolution or by decreasing the delay time from the default times to a time interval of ten times the reciprocal of the highest frequency component present on the input signal Hence to capture a signal of 1kHz a delay time of at least 10 ms is needed for a representative measurement of the wave form Figure 47 Signal path OVC Path block diagram offers three techniques for ACV measurement Track and Hold i Pal h L Table 31 Compares the ACV modes Analog Synchronous Random Bandwidth 10 Hz to 2 1 Hz to10 20 Hz to 10 MHz MHz MHz Best 300 ppm 100 ppm 1000 ppm Accuracy Reading Rate 50 rdgs s 10 rdgs s 40 rgds s Crest Factor 5 1 5 1 5 1 Waveforms _ All Repetitive All AC Cur
308. iate the remaining four readings 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 5 DIMENSION ARRAY FOR READINGS 30 OUTPUT 722 PRESET NORM SYN TRIGGER EVENT DCV NPLC 1 MEM OFF 40 OUTPUT 722 TARM SYN SYN TRIGGER ARM EVENT 50 OUTPUT 722 NRDGS 5 SYN 5 READINGS TRIGGER SYN SAMPLE EVENT 60 ENTER 722 Rdgs SYN EVENT ENTER READINGS 70 PRINT Rdgs PRINT READINGS 80 END TIMER The following program makes 4 readings in response to the synchronous trigger line 60 The first reading is made immediately after the preprogrammed default delay the remaining 3 have a 200ms interval between them 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 4 DIMENSION ARRAY FOR READINGS 30 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 TIMER 200E 3 SETS TIMER INTERVAL TO 200m SECONDS Chapter 6 Command Reference OCOMP Syntax Remarks OCOMP 50 OUTPUT 722 NRDGS 4 TIMER SELECTS 4 READINGS TRIGGER amp TIMER 60 ENTER 722 Rdgs TRIGGER AND ENTER READINGS 70 PRINT Rdgs PRINT READINGS 80 END The OCOMP command enables or disables the offset compensated ohms function OCOMP control control The control parameter choices are Numeric control Query Parameter Equiv Description OFF 0 Offset compensated ohms disabled ON 1 Offset compensated ohms enabled Power on control OFF Default control ON With offset comp
309. iately after the reading is taken The result can then be stored in reading memory or output over the GPIB When enabled a post process math operation except STAT and PFAIL is performed on each reading as it is removed or copied from reading memory to the display or the GPIB output buffer The readings in memory are not altered by any post process math operation The STAT or PFAIL post process math operations are performed using the readings in memory immediately after executing the MMATH command For the statistics operation results are stored in the statistics registers For the pass fail operation an out of limit reading sets bit number in the status register and displays either FAILED HIGH or FAILED LOW depending on whether the high or low limit was exceeded To enable a math operation send the MATH command for real time or the MMATH command for post process followed by the operation parameter DB DBM FILTER NULL PERC PFAIL RMS SCALE STAT or one of the temperature related parameters refer to Measuring Temperature later in this section for a listing of the temperature related parameters After enabling a math operation it remains enabled until you disable it cycle power execute RESET or execute one of the PRESET commands For example to enable the NULL operation send OUTPUT 722 MATH NULL ENABLES REAL TIME NULL OPERATION or OUTPUT 722 MMATH NULL ENABLES POST PROCESS NULL OPERATION Up to two math operati
310. ical order down arrow key or in reverse alphabetical order up arrow key For example starting with the TARM display shown above by pressing the down arrow key once the display shows the next command in alphabetical order TBUFF You can also press and hold the up or down arrow key to rapidly step through the menu Once you have found the desired command you can press the Enter key to execute it immediately using default parameter values if applicable If you need to specify command parameter s with the command displayed press the right arrow key or the comma key or if the first parameter is numeric a numeric key This selects the command and allows you to specify or select parameter s using the procedures described earlier in this section There are two alphabetic menus available FULL and SHORT You can select between these menus using the shifted Menu key The specified menu choice is stored in continuous memory not lost when power is removed The FULL menu contains all commands except query commands that can be constructed by appending a question mark to a command e g BEEP BEEP Query commands are discussed next The SHORT menu Query Commands Standard Queries Additional Queries Note Display Control Clearing the Display eliminates the GPIB bus related commands commands that are seldom used from the front panel and any commands that have dedicated front panel keys e g the NPLC key or the Trig key
311. ices are Remarks Example Numeric control Query Parameter Equiv Description OFF 0 Disables the input buffer commands are accepted only when the multimeter is not busy ON 1 Enables the input buffer commands are stored releasing the bus immediately Power on control OFF Default control ON Turning the input buffer OFF causes a minor degradation in speed performance but is useful for synchronizing bus activity With the input buffer OFF the multimeter accepts only one command at a time and does not release the bus until it has finished executing that command This ensures that subsequent commands sent to other bus devices cannot be executed until the multimeter has finished executing its command s Turning the input buffer ON causes the multimeter to buffer store incoming messages and release the GPIB bus as soon as message transmission is complete This allows the controller to communicate with other bus devices while the multimeter executes its command s However synchronization with other bus devices may be lost if they execute their instructions before the multimeter finishes its instructions In this case the ready bit in the status register may be monitored using a serial poll to determine when the multimeter is finished A series of commands longer than 255 characters fills the input buffer and causes the multimeter to halt bus activity while it executes the first commands received The remainder
312. igger is received on its Ext Trig connector before executing the next line of the subprogram This allows you to synchronize subprogram execution to external equipment e Any subprogram named 0 will be automatically executed whenever the multimeter has finished its power on sequence This is useful to recall the multimeter s previous state RSTATE 0 following a power failure e Subprograms are stored in continuous memory not lost when power is removed If you compress a subprogram however COMPRESS command the subprogram is removed from continuous memory and will be destroyed when power is removed Related Commands CALL COMPRESS CONT DELSUB PAUSE SCRATCH SUBEND 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM RDGS 5 DIMENSION ARRAY FOR 5 READINGS 30 OUTPUT 722 SUB DCCUR2 STORES FOLLOWING LINES NAMED DCCUR2 40 OUTPUT 722 PRESET NORM PRESETS 50 OUTPUT 722 MEM FIFO ENABLES FIFO MODE OF READING MEMORY 60 OUTPUT 722 DCV 10 01 DC VOLTAGE 10V RANGE 01 RESOLUTION 70 OUTPUT 722 NRDGS 5 AUTO 5 READINGS PER TRIGGER AUTO EVENT 80 OUTPUT 722 TRIG SGL SPECIFIES THE SINGLE TRIGGER MODE 90 OUTPUT 722 SUBEND SIGNALS THE END OF SUBPROGRAM STORAGE 100 OUTPUT 722 DISP MSG CALLING SUBPROGRAM 110 OUTPUT 722 CALL DCCUR2 120 ENTER 722 Rdgs 130 PRINT Rdgs 140 END When the following subprogram is called CALL EXTPACE the multimeter executes it line by line un
313. igh Speed Transfer Across GPIB in Chapter 4 for more information LOOPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20Num_samples 256 SPECIFY NUMBER OF SAMPLES 30INTEGER Int_samp 1 256 BUFFER CREATE INTEGER BUFFER 40ALLOCATE REAL Samp 1 Num_samples CREATE REAL ARRAY FOR SAMPLES 50ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 60ASSIGN Int_samp TO BUFFER Int_samp ASSIGN I O PATH NAME TO BUFFER 7OOUTPUT Dvm PRESET DIG TARM HOLD DCV 10V RANGE 256 SAMPLES 71 PER TRIGGER TIMER SAMPLE EVENT TIMER INTERVAL 20ys TRIG 75 LEVEL 0 AC COUPLED 3ys INTEGRATION TIME SINT FORMATS 8QOUTPUT Dvm TIMER 10E 6 10ys INTERVAL BETWEEN SAMPLES Q9QOUTPUT Dvm APER 1 4E 6 MAXIMUM APERTURE FOR 100kHZ SAMP RATE OQOUTPUT Dvm MEM FIFO ENABLE READING MEMORY FIFO MODE LOOUTPUT Dvm TARM SYN SYNCHRONOUS TRIGGER ARM EVENT 20TRANSFER Dvm TO Int_samp WAIT SYN EVENT TRANSFER READINGS INTO 21 READING MEMORY AND THEN INTO AN INTEGER ARRAY IN THE COMPUTER 22 SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS SINT NO DATA 23 CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED 3Q0OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR SINT FORMAT 40ENTER Dvm S ENTER SCALE FACTOR 50FOR I 1 TO Num samples 60 Samp I Int_samp I CONVERT EACH INTEGER READING TO REAL 65 FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE 70 R ABS Samp 1 USE ABSOLUTE VALUE TO CH
314. ill be used by the level detection circuitry Syntax SLOPE slope slope Selects the positive going or negative going slope of the input signal for use by the level detection circuitry The choices are Numeric slope Query Parameter Equiv Description NEG 0 Selects negative going slope POS 1 Selects positive going slope Power on slope POS Default slope POS Remarks Query Command The SLOPE query command returns the present slope 234 Chapter 6 Command Reference SMATH Example Syntax SMATH Refer to Query Commands near the front of this chapter for more information Related Commands LEVEL LFILTER NRDGS SSRC TRIG OUTPUT 7223 SLOPE POS LEVEL DETECTION Store Math Places a number in a math register SMATH register number register The registers that can be written to are Numeric register Query Parameter Equiv DEGREE 1 LOWER 2 MAX 3 MEAN 4 MIN 5 NSAMP 6 OFFSET 7 PERC 8 REF 9 RES 10 SCALE 11 UPPER 13 HIRES 14 PFAILNUM 15 Register Contents Time constant for FILTER and RMS Smallest reading in STATS Upper limit for PFAIL operation Average of readings in STATS Lower limit for PFAIL Number of samples in STATS Subtrahend in NULL and SCALE operations value for PERC operation Reference value for DB operation Reference impedance for DBM operation Divisor in the SCALE operation Largest reading in STATS Not used by any math operation The number of re
315. imeter to display only 7 4 digits You can use the NDIG 8 command to display all 8 2 digits refer to the NDIG command for details Default _ resolution For frequency or period measurements the default resolution is 00001 which selects a gate time of 1s and 7 digits of resolution For sampled ACV or ACDCYV the default resolution is 0 01 for SETACV SYNC or 0 4 for SETACV RNDM For all other measurement functions the default resolution time is determined by the present integration time Query Command The RANGE query command returns the present measurement range RANGE does not indicate the autorange mode use the ARANGE command to determine the autorange mode Refer to Query Commands near the front of this chapter for more information e Related Commands ARANGE FUNC R In the following program line 10 allows _resolution in line 30 to control the resolution The resolution specified by line 30 is 10mQ 10 OUTPUT 722 NPLC 0 SETS PLCS TO MINIMUM 20 OUTPUT 722 OHM SELECTS 2 WIRE OHMS 30 OUTPUT 722 RANGE 800 00125 SELECTS 800QLiMax 10mQ 40 END RESOLUTION Chapter 6 Command Reference 223 RATIO RATIO Syntax Remarks Example The RATIO command instructs the multimeter to measure a DC reference voltage applied to the Q Sense terminals and a signal voltage applied to the Input terminals The multimeter then computes the ratio as Signal Voltage Ratio DC Reference V
316. ine how many readings can be stored using a particular format divide the reading memory size first response returned by the MSIZE command by the number of bytes per reading shown above Single Integer SINT or Double Integer DINT Use the SINT memory format when making low resolution measurements 3 5 or 4 5 digits at the fastest possible rate on a fixed range autorange disabled Since the SINT format is only 2 bytes per reading you can store more readings using SINT than in any other memory format Use the DINT memory format when making high resolution measurements 5 5 digits or greater at the fastest possible rate on a fixed range Note When using the SINT or DINT memory format the multimeter applies a scale factor to the readings The scale factor is based on the multimeter s configuration measurement function range A D converter setup and enabled math operations When recalling readings the multimeter calculates the scale factor based on its present configuration Ifthe configuration was changed since the readings were stored a different scale factor may be used which produces incorrect readings When recalling stored readings it is very important that the multimeter be configured as it was when the readings were stored You should not use the SINT or DINT format for frequency or period measurements when a realtime or post process math operation is enabled except STAT or PFAIL or when autorange is enabled e
317. ined states PRESET type type Specifies the NORM FAST or DIG preset state the numeric query equivalents of these parameters are 1 0 and 2 respectively Power on type not applicable Default type NORM NORM PRESET NORM is similar to RESET but optimizes the multimeter for remote operation Executing PRESET NORM executes the following commands ACBAND 20 2E 6 MEM OFF last memory operation set to FIFO Chapter 6 Command Reference 217 PRESET 218 AZERO ON MFORMAT SREAL BEEP ON MMATH OFF DCV AUTO NDIG 6 DELAY 1 NPLC 1 DISP ON NRDGS 1 AUTO FIXEDZ OFF OCOMP OFF FSOURCE ACV OFORMAT ASCII INBUF OFF TARM AUTO LOCK OFF TIMER 1 MATH OFF TRIG SYN All math registers set to 0 except DEGREE 20 PERC 1 REF 1 RES 50 SCALE 1 FAST PRESET FAST configures the multimeter for fast readings fast transfer to memory and fast transfer from memory to GPIB Refer to Increasing the Reading Rate in Chapter 4 for more information on fast measurements Executing PRESET FAST executes the commands shown under PRESET NORM with the following exceptions DCV 10 AZERO OFF DISP OFF MFORMAT DINT OFORMAT DINT TARM SYN TRIG AUTO DIG PRESET DIG configures the multimeter for DCV digitizing DCV digitizing is discussed in Chapter 5 Executing PRESET DIG executes the commands shown under PRESET NORM with the following exceptions DCV 10 AZERO OFF DELAY 0 DISP OFF TARM HOLD TRIG LEVEL LEVEL 0 AC
318. information because of the broadening of the sample aperture To capture the peak value of a pulse the aperture must be no wider than the pulse width From a practical viewpoint trigger uncertainty can make the task of capturing peak amplitudes nearly impossible for pulses near the width of the sampling aperture The solution is to narrow the aperture to a point where the bandwidth of the input amplifier is the resolution limiting factor not the sample aperture Appendix E High Resolution Digitizing With the 3458A 351 Path for Direct or Using the Track and Hold Sequential Sampling Figure 52 The 3458A Multimeter provides two different digitizing paths the standard DCV path and a track and hold path The track and hold path is the solution to capturing the amplitude of narrow pulses This path has a bandwidth of 12 MHz and a fixed aperture of 2 ns With trigger jitter of 2 ns you can with a little searching capture the peak amplitude of a pulse as narrow as 40 ns without measurement degradation as indicated in Figure 53 Rise times of less than 10 ns will cause overshoot in a digitized measurement hence if it is likely that signals with these frequency components will be applied to the input of the 3458A then bandlimit the signal by filtering Direct digitizing with the track and hold path allows the capture of signals with frequency components up to 12 MHz The same path is used to subsample repetitive signals up to 12
319. ing aid 30 lxx COMMON 40 COM Hp3458 Recorder Xist_plotter Prt Bus Xist 50 Real Arrays 60 REAL Scal 0 4 Yamp 0 7 70 lek STRINGS 80 DIM Source 50 Destin 50 Titles 30 90 x INTEGER ARRAYS 00 INTEGERWavf 1 16384 Redg 0 30 Fedg 0 30 Bandwf 0 163 10 DISP Clear display line 20 OUTPUT I USING Clear CRT 30 40 CALL Init58 Wake up the bus 50 i 60 GINIT Initialize graphics 70 80 Insert user main program here 250 to here 260 END Returning to the original problem the subprograms needed to analyze the AM modulated signal are Setup _dig Wfdgtz Wfmove Fft and Fft_plot In other words the following would be inserted as the main program 190 CALL Setup_dig 2 20E 6 512 200 CALL Wfdgtz 1 210 CALL Wfmove 1 98 Scal Wavf Clip 220 CALL Fft 512 1 Hanning Wavf Real_dat Imag_ dat Magn_dat 240 CALL F t_plot Magn _data Smpl_intvl Dyn_range F_ start F_stop Title 250 END The results of this program are shown in Figure 59 Appendix E High Resolution Digitizing With the 3458A 357 Figure 59 Example of results generated using the Wave Form Analysis Library 8 Frequency Domain Data MAG Normalized Magnitude 0 32 64 96 128 Sample Frequency interval 390 625 Hz Errors in Measurements The flexibility of the 3458A helps you avoid or compensate for many of the measurement errors that can occur in the digitizing process
320. ing and then divide each reading by 2 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 20 DIMENSION ARRAY FOR 20 READINGS 30 OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 TRIG SYN 40 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 50 OUTPUT 722 NRDGS 20 20 READINGS PER TRIGGER 60 OUTPUT 722 MMATH SCALE ENABLE POST PROCESS SCALE OPERATION 70 OUTPUT 722 SMATH OFFSET 1 WRITE 1 TO OFFSET REGISTER 80 OUTPUT 722 SMATH SCALE 2 WRITE 2 TO SCALE REGISTER 90 OUTPUT 7227 TRIG SGL TRIGGER READINGS 100 ENTER 722 Rdgs RECALL READINGS USING IMPLIED READ ToS PERFORM SCALE OPERATION ON EACH 110 PRINT Rdgs PRINT MATH RESULTS 120 END Chapter 4 Making Measurements 119 120 10 20 30 40 50 60 70 80 90 10 20 30 40 50 60 70 80 90 95 100 110 Percent The PERC math operation determines the difference in percent between each reading and the value in the PERC register The equation is Result Reading PERC PERC e 100 Where Reading is any reading PERC is the value stored in the PERC register power on value 1 You can use the PERC math operation to determine the difference in percent between an ideal value and the measured value For example the following program determines the percent error of a 10 VDC voltage measurement Line 60 enters the ideal value 10 into the PERC register Line 70 triggers the 20 readings Ifa reading is exactly 1
321. ion The second number is the slave processor firmware revision Syntax REV Example 10 OUTPUT 722 20 ENTER 722 30 PRINT A B 40 END REV A B READ FIRMWARE REVISION NUMBERS ENTER NUMBERS PRINT NUMBERS RMATH Recall Math Reads and returns the contents of a math register Syntax RMATH register register The register parameter choices are register Parameter DEGREE LOWER MAX MEAN MIN NSAMP OFFSET PERC Numeric Query Equiv 1 0 ON Dn HH HR YW N Register Contents Time constant for FILTER and RMS Smallest reading in STATS Upper Limit for PFAIL operation Average of readings in STATS Lower limit for PFAIL Number of samples in STATS Subtrahend in NULL and SCALE operations value for PERC operation Reference value for DB operation Reference impedance for DBM operation Divisor in the SCALE operation Standard deviation in STATS Largest reading in STATS Not used by any math operation extra register 228 Chapter 6 Command Reference RMEM Remarks Example Syntax RMEM Numeric register Query Parameter Equiv Register Contents PFAILNUM 15 The number of reading that passed PFAIL before a failure was encountered Power on register none Default register DEGREE Math register contents are always output in the ASCII output format regardless of the specified output format Afterwards the output format returns to that previously specified SINT DINT S
322. ion Time 3 9 ms FILTER 1 pole digital filter Weighted Average of inputs Minimum Execution Time 750 us CTHRM FTHRM C F temperature conversion for 5 kQ thermistor Keysight 40653B Minimum Execution Time 160 us CTHRM10K FTHRM10K C F temperature conversion for 10 kQ thermistor Keysight 40653C Minimum Execution Time 160 us CRTD92 FRTD92 C F temperature conversion for RTD of 100 Q Alpha 0 003916 Minimum Execution time 160 us 11 General Specifications Operating Environment Temperature Range 0 C to 55 C Operating Location Indoor Use Only Operating Altitude Up to 2 000 Meters Pollution Rating IEC 664 Degree 2 Operating Humidity Range up to 95 RH at 40 C Physical Characteristics 88 9 mm H x 425 5 mm W x 502 9 mm D Net Weight 12 kg 26 5 Ibs Shipping Weight 14 8 kg 32 5 Ibs Storage Temperature 40 C to 75 C Warm Up Time 4 Hours to published specifications Power Requirements 100 120 V 220 240 V 10 48 66Hz 360 420Hz auto sensed lt 30 W lt 80 VA peak Fused 1 5 115 V or 0 5 A 230 V Cleaning Guidelines To clean the instrument use a clean cloth slightly dampened with water Field Installation Kits Option 001 Extended Reading Memory Option 002 High Stability Reference Extra Keyboard Overlays 5 each Warranty Period One year Input Terminals Gold plated Tellurium Copper Input Limits Input HI to LO 300 Vac Max CAT II
323. ions Figure 49 Shows benchmark execution times for different Sow Eos oS os Default e e la rs E 5 2H n configurations Ss Test Execution Time log scale oS 10 The measurement sequence demands that the resistance values be checked before the circuit is powered Then the powerline voltage is checked for proper level The output level 1 V at 5 kHz is checked to limits of 075 Finally the remaining voltages are checked in the following sequence 2 DCV lt 10 V 1 1 DCV lt 10 V 2 DCV lt 10 V Appendix D Optimizing Throughout and Reading Rate 333 1 DCV lt 1 V 001 1 ACV lt 10 V 4 1 1 DCV lt 10 V 41 3 DCV lt 10 V 4 01 Benchmark Results Default Conditions Subprogram Default time 20 63 s 560 SUB Default REAL Dnld_time Exe time Tns_ time 570 DIM A 37 580 Exe time TIMEDATE 590 OUTPUT 722 RESET TRIG SYN 600 OUTPUT 722 OHM 610 FOR I 1 TO 23 620 ENTER 722 A 1 630 NEXT 640 OUTPUT 722 OHMF 780 ENTER 722 A I 790 NEXT 800 Exe time TIMEDATE Exe time 810 Dnlid_time 0O 820 Tns_time 0 830 SUBEND The 3458A is placed in remote operation by the computer and is reset to its default conditions The integration time is set to 10 PLC the settling delays are set so that first reading after a function or a range change meets its specified accuracy Auto range is on The computer asks the dmm to change range or f
324. ions will take more time in the neighborhood of 30 to 40 ms than between DCV and Ohms Resistance measurements require more settling time than DCV measurements Above 10 kQ longer settling time is introduced to make sure that the first reading is correct within specified limits Again if you wish to compromise the accuracy of the first reading the settling time associated with the higher resistance measurements may be defeated by using the default delay Before you change the program s delay setting to a lesser value experiment with the application to determine the optimum settling time Figure 45 shows the general trend in increasing settling times as a function of increasing resistance for first reading right Appendix D Optimizing Throughout and Reading Rate SSS EEE i Figure 45 Settling time characteristic for resistance measurements assuming lt 200pF shunt capacitance in the circuit tested For small values of resistance there is no real advantage to setting the delay to less than the default values Resistance above 100 kW require longer settling times to reach final values hence settling delay times for these values may save measurement time at the expense of measurement accuracy Settling Time 5 E gas gt amp 10 100 if 10 16 10 oE iw Resistance lt 2 Assuming lt 200 pF shunt capacitance Another feature of the 3458A is OffsetCompensated Ohms Very much like auto zero in concept offse
325. is removed e Query Command The BEEP query command returns the present beeper mode Refer to Query Commands near the front of this chapter for more information Related Commands TONE OUTPUT 722 BEEP OFF DISABLES THE BEEPER This is a calibration command Refer to the 3458 Calibration Manual for details Call Subprogram Executes a previously stored subprogram CALL name Subprogram name A subprogram name may contain up to 10 characters The name can be alpha alphanumeric or an integer in the range of 0 to 127 Refer to the SUB command for details Power on name none Chapter 6 Command Reference CALNUM CALSTR Remarks Examples Syntax Remarks Example CALNUM Default name 0 Subprograms are created with the SUB command The multimeter sets bit 0 in the status register after executing a stored subprogram From the front panel you can view all stored subprogram names by accessing the CALL command and pressing the up or down arrow key Once you have found the correct subprogram press the Enter key to execute the subprogram Related Commands COMPRESS CONT DELSUB PAUSE SCRATCH SUB SUBEND OUTPUT 722 CALL DCCUR2 EXECUTES SUBPROGRAM NAMED DCCUR2 Calibration Number Query Returns an integer indicating the number of times the multimeter has been calibrated CALNUM The calibration number is incremented by 1 whenever the multimeter is calibrated If autocal i
326. is taken per sample event until the specified number of readings are completed EXT EXT AUTO EXT TIMER After two negative edge transitions on the Ext Trig input one LINE LEVEL reading is taken per sample event until the specified number of readings are completed EXT EXT SYN Illegal EXT LEVEL AUTO EXT TIMER After a negative edge transition on the Ext Trig input followed LEVEL by the occurrence of the LEVEL event one reading is taken per sample event until the specified number of readings are completed EXT LEVEL SYN LINE Illegal 1 The LEVEL event occures when the specified voltage is reached on the specified slope of the input signal The LEVEL trigger event or sample event can only be used for DC voltage or direct sampled measurements 2 The output buffer must be empty and reading memory must be OFF or empty for the SYN event to occur 3 The input buffer must be enabled or you must suppress cr If when sending the TARM SGL command Chapter 4 Making Measurements 89 Table 21 Event Combinations Trigger Arm Trigger Sample Description Event Event Event EXT LINE AUTO EXT TIMER After a negative edge transition on the Ext Trig input followed LINE by the power line voltage crossing zero volts one reading is taken per sample event until the specified number of readings are completed EXT LINE SYN LEVEL Illegal EXT SGL ANY Illegal EXT SYN SYN Af
327. it indicates a programming or syntax error A 200 series prefix e g 209 indicates a hardware error When you get a hardware error 200 series prefix run the self test again If you repeatedly get the error the multimeter may need repair If the ERR annunciator is still illuminated more errors have been recorded Repeat the above key sequence until all errors have been read and the ERR annunciator is no longer illuminated When you have read all the errors the error annunciator goes off If you try to read another error the display shows You do not have to run self test to get an error The multimeter detects errors that occur while entering data when changing functions or ranges and so on The multimeter beeps whenever it detects an error Whenever you want to clear information such as an error description from the display and return it to displaying measurements press Clear Back Space You can also clear the display by repeatedly pressing the Back Space key Chapter 2 Getting Started 31 Resetting the Multimeter Caution Using the Configuration Keys 32 Chapter 2 Getting Started unshifted Many times during operation you may wish to return to the power on state The front panel Reset key returns you to the power on state without having to cycle the multimeter s power To reset the multimeter press Reset ma The multimeter begins the reset process with a display test which illuminate
328. ith less than 175 ns trigger latency and less than 100 ps Appendix E High Resolution Digitizing With the 3458A 349 Digitizing Analog Signals Avoiding Aliasing measurement to measurement jitter Through the track and hold path the 3458A can digitize repetitive signals up to 12 MHz at 50 kSamples s with 16 bits resolution by using sequential sampling subsampling Most digital signal processing systems may be represented as illustrated in Figure 50 In any digital processing system there is a minimum allowable sampling rate called the Nyquist Rate and it is specified by the Sampling Theorem summarized as follows When digitizing an analog signal the sampling rate must be a least twice as great as the highest frequency component f in the spectrum of the sampled signal Frequency components higher than f will alias down into the frequency range below fp and interfere with the accurate representation of the sampled signal For example since a square wave can be represented as an infinite sum of sinusoids Fourier Series and contains very high frequency components attempting to digitize this signal without an anti aliasing filter on the input will severely alias the captured signal so that representations of the actual signal may be meaningless Figure 50 ANALOG INPUT In general digital signal processing systems ANTTALASNG FLTER i xx gt require a close look at ET various functions OR INTEGRATOR inning with th b
329. itions Rate DCV Autorange Rate 100 mV to 10 V 110 sec Execute simple command changes CALL OCOMP etc 330 sec Readings to GPIB ASCII 630 sec Readings to GPIB DREAL 1000 sec Readings to GPIB DINT 50 000 sec Readings to internal memory DINT 50 000 sec Readings from internal memory to GPIB DINT 50 000 sec Readings to GPIB SINT 100 000 sec Readings to internal memory SINT Readings from internal memory to GPIB SINT Maximum internal trigger reading rate Maximum external trigger reading rate 100 000 sec 100 000 sec 100 000 sec 100 000 sec Memory Standard Option 001 Readings Bytes Readings Bytes Reading Storage 16 bit 10 240 20k 65 536 128 k Non volatile for subprograms and or state storage 14k Delay Time Accuracy 0 01 5 ns Maximum 6000 s Timer Resolution 10 ns Accuracy 0 01 5 ns Jitter 50 ns pk pk Maximum 6000 s Resolution 100 ns Jitter lt 100 ps rms Using HP 9000 Series 350 SINT data is valid for APER lt 10 8ps Appendix A Specifications 297 9 Ratio in 1 Type of Ratio 1 All SETACV measurement DCV DCV Ratio Input Reference types are selectable ACV DCV Reference HI Sense to LO LO Sense to LO LO Sense to LO limited to ACDCV DCV Reference Signal Range 12 V DC autorange only 0 25 V Accuracy Input error Reference Error Input error 1 x Total Error for input signal measurement function
330. l 500 10 0 1 10 error for Keysight factory 0 5 10 1 10 traceability of 10 KQ to US NIST Two Wire Ohms Accuracy For Two Wire Ohms OHM accuracy add the following offset errors to the Four Wire Ohms OHMF external calibration accuracy 24 Hour 50 mQ 90 Day 150 mQ 1 Year 250 mQ 2 Year 500 mQ Additional Errors ppm log scale 0 01 10 100 1000 0 01 0 1 1 Integration Time in Number Power Line Cycles NPLC log scale RMS Noise Range Multiplier 10Q2 amp 100Q x10 Ik Q to 100kQ x1 1 MQ x1 5 10 MQ x2 100 MQ x120 1 GQ x1200 Settling Characteristics For RMS noise error multiply RMS noise result from graph by multiplier in chart For peak noise error multiply RMS noise error by 3 For first reading error following range change add the total 90 day measurement error for the current range Preprogrammed settling delay times are for lt 200 pF external circuit capacitance 286 Appendix A Specifications Traceability is the absolute error relative to National Standards associated wifh the source of last Selected Reading Rates A Readings Sec 4 For PRESET DELAY 0 DISP i Auto Zero Auto Zero OFF OFORMAT DINT NPLC gt Aperture Digits Off On ARANGE OFF 0 0001 1 4us 4 5 100 0007 4 130 For OHMF or OCOMP ON the 0 0006 10 ps 5 5 50 000 3 150 maximum reading rates will be 0 01 167us 6 5 5 300 930 slower 6 5 Ohms measurements at rates lt al oe ne 6 3 32
331. l s Last Entry key will not display the codes used in a previously executed SECURE command e Related Commands ACAL CAL CALNUM CALSTR SCAL Changing the Code OUTPUT 722 SECURE 3458 4448 0N CHANGE FACTORY SECURITY CODE TO 4448 ENABLE AUTOCAL SECURITY Disabling Security OUTPUT 722 SECURE 3458 0 DISABLES SECURITY FOR CALIBRATION AND AUTOCAL Set ACV Selects the RMS conversion technique to be used for AC or AC DC voltage measurements SETACV type type The type parameter is used to select the measurement method analog random Chapter 6 Command Reference 233 SLOPE sampling or synchronous sampling The parameters are Numeric type Query Parameter Equiv Description ANA 1 Analog RMS conversion RNDM 2 Random sampling conversion SYNC 3 Synchronous sampling conversion Power on type ANA Default type ANA Remarks Bandwidth limitations vary with the conversion technique selected See the Specifications in Appendix A for details Query Command The SETACV query command returns the present AC measurement method Refer to Query Commands near the front of this chapter for more information Related Commands ACBAND ACDCV ACV FUNC SSRC Example 10 OUTPUT 722 SETACV SYNC SPECIFIES SYNCHRONOUS SAMPLING DC COUPLED 20 OUTPUT 722 ACDCV SELECTS AC DC VOLTAGE MEASUREMENTS 30 END SLOPE SLOPE is used in conjunction with the LEVEL command and specifies which slope of the signal w
332. lem in reconstructing the wave form as it is presented to the computer If you use the memory for data storage before transferring the captured signal the 3458A orders the data for you The Wave Form Analysis Library 3458A Option 005 03458 80005 not only lets you acquire the wave form without having to use even the simple commands to control the 3458A but it also lets you analyze and present the data with a minimum of computer and instrument knowledge A simple sequence of measurement setup measurement acquisition analysis and presentation is all that you have to keep in mind while developing your master program that calls up both BASIC language and compiled subprograms Refer to Figure 58 Appendix E High Resolution Digitizing With the 3458A 355 356 Figure 58 Here isa init58 Initialize program typical way to structure your own automatic measurement program using the Library Wtdgtz Capture wave form and Subprograms not Wimove transfer data to computer necessarily a complete list Wipeak ff wiper wirms E wewttn one l Output results and Resutt Wiolot Wwimove Store wave form on disc In addition to time domain analysis like frequency risetime pulse width and overshoot the Wave Form Analysis Library offers frequency domain analysis with Fast Fourier Transform FFT and Inverse Fourier Transform IFT with the Hanning filter function Further the Wave Form Analysis Library gives you a Fast Scope program that
333. ling are that the input signal must be periodic repetitive and sub sampling is not a real time measurement You specify sub sampling using the SSAC or SSDC command The SSAC command selects AC coupled sub sampling which digitizes only the AC component of the input signal The SSDC command selects DC coupled sub sampling which digitizes the combined AC and DC components of the signal In sub sampling the samples in the composite waveform can be spaced very closely together This means that the interval between samples in the composite waveform effective_interval can be much smaller and the effective sampling rate much greater than in the DCV or direct sampling methods For example assume you need to digitize a repetitive 10kHz input signal with a 5us effective_interval between samples This is a sampling rate of 1 5e 6 or 200 000 samples per second This application would be impossible using DCV or direct sampling since their maximum sampling rates are 100 000 and 50 0000 samples per second respectively Figure 31 illustrates how this can be done using sub sampling The effective_interval is specified as Sus and specified number of samples is 20 The effective_interval and the total number of samples are specified by the SWEEP command After specifying the effective_interval and the number of samples the multimeter calculates how many bursts a burst is a group of samples it needs to make and how many samples will be in each burst Fo
334. llers using BASIC language The TRANSFER statement is the fastest way to transfer readings across the GPIB especially when used with the direct memory access DMA GPIB interface You should use the TRANSFER statement whenever measurement transfer speed is important 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_readings DECLARE VARIABLE 30 INTEGER Int_rdgs 1 10 BUFFER CREATE INTEGER BUFFER ARRAY 40 REAL Rdgs 1 10 CREATE REAL ARRAY 50 Num_readings 10 NUMBER OF READINGS 10 60 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 70 ASSIGN Int_rdgs TO BUFFER Int_rdgs ASSIGN BUFFER I O PATH NAME 80 OUTPUT Dvm PRESET NORM OFORMAT SINT NPLC 0 NRDGS Num_ readings 85 TARM AUTO TRIG SYN SINT OUTPUT FORMAT MIN NTEGRATION TIME 90 TRANSFER Dvm TO Int_rdgs WAIT SYN EVENT TRANSFER READINGS INTO 91 INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS 95 SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED LOOOUTPUT Dvm I SCALE QUERY SCALE FACTOR FOR SINT FORMAT 110ENTER Dvm S ENTER SCALE FACTOR 120FOR I 1 TO Num_readings 130Rdgs I Int_rdgs I CONVERT EACH INTEGER READING TO REAL 135 FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE 140R ABS Rdgs I USE ABSOLUTE VALUE TO CHECK FOR OVLD 150IF R gt 32767 THEN PRINT OVLD IF OVLD PRINT OVERLOAD MESSAGE 160Rdgs I Rdgs I S MULTIPLY READING TIMES SCALE FACTOR 170Rdgs I DROU
335. lope for level triggering SSRC LEVEL AUTO Level sync source event auto synchronous AC voltage SWEEP IOOE 9 1024 Sample interval 100 nanoseconds 1024 samples TARM AUTO Auto trigger arm event TBUFF OFF Disable external trigger buffering TIMER 1 1 second timer interval TRIG AUTO Auto trigger event All math registers set to 0 except DEGREE 20 REF SCALE 1 RES 50 PERC 1 In the power on state the display is continuously updated with each new DC voltage reading Along the bottom of the display are a series of annunciators These annunciators alert you to a variety of conditions For example the SMPL annunciator flashes whenever the multimeter has completed a reading Table 6 describes the meaning of each display annunciator Display Annunciator SMPL Table 6 Display Annunciators Description Flashes whenever a reading is completed REM The multimeter is in the GPIB remote mode SRQ The multimeter has generated a GPIB service request TALK The multimeter is addressed to talk on GPIB LSTN The multimeter is addressed to listen on GPIB AZERO OFF Autozero is disabled MRNG Autorange is disabled the multimeter is using a fixed range MATH One or two real time or post process math operations enabled ERR An error has been detected SHIFT The shift key has been pressed MORE INFO More information concerning the present configuration is available use the right arrow key to
336. lowing program statement compresses subprogram TEST 12 previously downloaded OUTPUT 722 COMPRESS TEST12 Continue Resumes execution of a subprogram that has been suspended by a PAUSE command CONT The GPIB Group Execute Trigger function may also be used to resume execution of a suspended subprogram e Only one subprogram will be preserved in a suspended state If a subprogram is paused and another is run which also becomes paused the first will be terminated and the second will remain suspended Related Commands PAUSE SUB SUBEND OUTPUT 722 CONT CONTINUE SUBPROGRAM EXECUTION Clear Status Byte Clears sets to 0 all bits in the status register CSB If a condition that set a bit in the status register still exists that bit will be set again immediately after the CSB command is executed e When you clear bit 6 service requested the multimeter sets the GPIB SRQ line false Related Commands RQS SPOLL GPIB command STB Example OUTPUT 722 CSB CLEARS THE STATUS REGISTER Chapter 6 Command Reference 167 DCI DCV DCI DCV Refer to the FUNC command DEFEAT Enables or disables the multimeter s input protection algorithm see CAUTION below and some syntax and error checking algorithms With these algorithms disabled the multimeter can change to a new measurement configuration faster than it can with them enabled Syntax DEFEAT mode mode The mode parameter choices are Num
337. lt delay changes automatically unless you have specified an alternate value whenever you change the measurement function DCV ACV etc the range the resolution or the AC bandwidth setting ACBAND command Query Command The DELAY query returns the present delay time in seconds Refer to Query Commands near the front of this chapter for more information Related Commands NRDGS SWEEP TIMER TRIG OUTPUT 722 DELAY 5 INSERTS A 5 SECOND DELAY OUTPUT 722 DELAY 1 RETURNS TO AUTOMATIC DEFAULT DELAY 170 Chapter 6 Command Reference DELSUB DIAGNOST DISP Syntax name Remarks Example Syntax control DELSUB Delete Subprogram Removes a single subprogram from memory DELSUB name Subprogram name A subprogram name may contain up to 10 characters The name can be alpha alphanumeric or an integer in the range of 0 to 127 Refer to the SUB command for details Power on name none Default name none parameter required When a subprogram is deleted the memory used to store it is freed and may be used to store a new subprogram see the SUB command e To delete all subprograms at once use the SCRATCH command Related Commands COMPRESS SCRATCH SUB OUTPUT 722 DELSUB TEST12 DELETES SUBPROGRAM TEST12 This is a service related command Refer to the 3458A Service Manual for details Display Enables or disables the multimeter s display and may also be used to send a message to
338. ltimeter be certain that the multimeter is in a protective package use the original shipping containers and cushioning materials to prevent transit damage Such damage is not covered by warranty Attach a tag to the shipment identifying the owner and indicating the service or repair needed Include the model number and serial number of the multimeter We suggest that you insure the shipment 22 Chapter 1 Installation and Maintenance Chapter 2 Getting Started Tito duction wiscciscuceaccsceksacseevendennsea devas a cennensdentenase 25 Before Applying Power cccecccsseesceteeseeerseesees 25 Applying Power 2 0 cceeeecceseesesseeeecescesecaeeeeeaeenee 25 Power On Self Test 0 0 cccccecceeeeesseceeeeceteeseeseees 25 Power On State oo cece eeeeseeeseceseeseeceneeeeeeenees 25 The Display enrera tnn A 26 Operating from the Front Panel cee eeeeeeees 27 Making a Measurement 0 0 0 ccceeceeseeeeeeeeeeeeee 28 Changing the Measurement Function 28 Autorange and Manual Ranging cee 29 Holdena a a a tea a steer ee 29 Manual Ranging cccecceesseeseceteeeteeeneeeees 30 Self Test ienien sad seis a E e aSa 30 Reading the Error Register 0 eeecceseeeeeereeeee 31 Resetting the Multimeter sssissseseseeeeeeeeeeeseee 32 Using the Configuration Keys ccceeeee 32 Selecting a Parameter cccceesceseeereeees 33 Default Valuessaan ei 34 Numeric Parameters s 34 Expone
339. ly one or two of these events and leave the other event s set to AUTO This section describes the various events that can be used to satisfy the trigger arm trigger and sample event requirements and contains examples showing how to use these events The examples in this manual are intended for Hewlett Packard Series 200 300 computers using BASIC language They assume a GPIB interface select code of 7 and a device address of 22 resulting in a combined GPIB address of 722 Some of the examples in this section store readings in memory while others transfer readings to the controller Reading destination is discussed in detail later in this chapter under Using Reading Memory and Sending Readings Across the Bus ALL SPECIFIED READINGS TAKEN TRIGGER EVENT OCCURS SAMPLE EVENT OCCURS ma TAKE 1 READING BASBOPC F 4 1 Figure 16 Triggering hierarchy Chapter 4 Making Measurements 81 82 The Trigger Arm Event The Trigger Event The Sample Event Event Choices When the specified trigger arm event occurs it arms the multimeter s triggering mechanism That is the trigger arm event enables a subsequent trigger event You specify the trigger arm event using the TARM command When the specified trigger event occurs and the trigger arm event has already occurred it enables a subsequent sample event You specify the trigger event using the TRIG command When the sample event occurs and the trigg
340. m of reading additional error for Keysight factory traceability of 10V DC to US NIST Maximum DC is limited to 400V in ACV function 291 AC DCV Accuracy ACDCV Function For ACDCV Accuracy apply the following additional error to the ACV accuracy of Range DC lt 10 of AC Voltage ACBAND ACBAND Temperature DC gt 10 of AC Voltage ACBAND ACBAND Temperature Range lt 2MHz gt 2MHz Coefficient lt 2MHz gt 2MHz Coefficient 10 mV 0 09 0 09 0 03 0 7 0 7 0 18 100 mV 1 kV 0 008 0 09 0 0025 0 07 0 7 0 025 at 1 Additional error beyond 1 C Additional Errors but within 5 C of last Apply the following additional errors as appropriate to your particular measurement setup of Reading ACAL e a S Crest Factor Resolution Multiplier of Reading C rest Factor Resolution er Input Frequency a antec For ACBAND gt 2 MHz use Source R 0 1 MHz 1 4 MHz 4 8 MHz 8 10 MHz 1 2 Resolution in x 1 10 mV range temperature 02 0 2 5 5 2 3 Resolution n x3 coefficient for all ranges 50 Q Terminated 0 003 0 0 0 34 Pesolunon th A 75 Q Terminated 0 004 2 5 5 T gt Resolution noeg 2 Flatness error including 509 0 005 3 7 10 instrument loading Reading Rates 3 Sec Reading High Frequency Temperature Coefficient 3 For DELAY 1 ARANGE Resolution ACV ACDCV For outside Tcal 5 C add the following error OFF For DELAY 0 in ACV 01 02 40 39 of Readin g C the reading rates are identical 0 2 0
341. mand is allowed in any one subprogram Additional SUB or SUBEND commands will generate errors The DELSUB delete subprogram command deletes the specified subprogram from internal memory but does not delete the subprogram name Chapter 7 BASIC Language for the 3458A 275 276 SCRATCH CAT LIST COMPRESS itself from the catalog listing of subprograms CAT command The SCRATCH command deletes scratches all 3458A subprograms variables and arrays from internal memory It also deletes all name definitions from the catalog listing CAT command If SCRATCH is executed when a subprogram is running an error is generated but the subprogram is not purged from memory The CAT catalog command lists the names of all 3458A subprograms simple variables stored states and arrays that are presently stored in internal memory If there are no more arrays or subprograms to be listed the CAT command returns the word DONE Refer to chapter 3 for more information on stored states The format for the catalog is For Subprograms SUB sub_name For Integer Arrays LARRAY array_name For Real Arrays RARRAY array_name For Stored States STATE state_name non volatile memory For Simple Variables INT variable_name REAL variable_name The following program shows how to use the CAT command 10 DIM AS 80 20 OUTPUT T22e CAT 30 REPEAT 40 ENTER 722 AS 50 PRINT A 60 UNTIL AS DONE 70 END The LIST command allows you to list the spe
342. mark and returns one or more responses to a particular question For example the ID query command returns the response HP 3458A The following standard query commands are documented individually in this chapter AUXERR LINE CALNUM MCOUNT ERR OPT ERRSTR REV ID SSPARM ISCALE STB TEMP In addition to the standard query commands you can create others by appending a question mark to any command that can be used to configure or program the multimeter Query commands of this type are not documented individually in this chapter Instead they are combined with the parent command That is the AZERO command page contains information on both AZERO and AZERO As an example the AZERO command enables or disables the autozero function The possible autozero modes are OFF ON or ONCE You can determine the present autozero mode by appending a question mark to the AZERO command as shown in the following program 10 OUTPUT 722 AZERO 20 ENTER 722 AS 30 PRINT AS 40 END In the power on state the multimeter returns numeric responses to query commands For example the above program might return 1 which is the numeric query equivalent of the ON parameter Numeric query equivalents are listed under each applicable command in this chapter For commands that have parameter choices such as the AZERO command the query version of the command returns the presently specified choice or its numeric query equivalent Many commands
343. mat for FREQ or PER measurements when a realtime or post process math operation is enabled except STAT or PFAIL or when autorange is enabled 2 Level triggering is the default sync source event for synchronous ACV or ACDCV however the level trigger voltage and the slope are determined automatically and cannot be specified 3 You cannot use the LEVEL trigger or sample event for FREQ or PER measurements You can however specify the voltage level and slope that the level detection circuits use to measure frequency or period 4 You cannot use MATH for sub sampling you can use MMATH for sub sampling 5 For sub sampling when using reading memory the memory format must be SINT When not using reading memory the output format must be SINT 156 Chapter 6 Command Reference ACAL ACAL Syntax type security_code Remarks Autocal Instructs the multimeter to perform one or all of its self calibrations ACAL type security_code The type parameter choices are Numeric type Query Parameter Equiv Description ALL 0 Performs the DCV OHMS and AC autocals DCV 1 DC voltage gain and offset see first Remark AC 2 ACV flatness gain and offset see second Remark OHMS 4 OHMS gain and offset see third Remark Power on type none Default type ALL When autocal is secured you must enter the correct security code to perform an autocal When autocal is not secured no security code is required Refer to the SECU
344. mation on triggering measurements Chapter 3 Configuring for Measurements 51 Presetting the The PRESET NORM command is similar to the RESET command but Multimeter configures the multimeter to a good starting point for remote operation RESET is primarily for front panel use It s a good idea to execute PRESET NORM as the first step when configuring the multimeter since it sets the multimeter to a known configuration and suspends readings by setting the trigger event to synchronous TRIG SYN command Table 10 shows the commands executed by the PRESET NORM command Table 10 PRESET NORM State Command Description ACBAND 20 2E 6 AC bandwidth 20Hz 2MHz AZERO ON Autozero enabled BEEP ON Beeper enabled DCV AUTO DC voltage measurements autorange DELAY 1 Default delay DISP ON Display enabled FIXEDZ OFF Disable fixed input resistance FSOURCE ACV Frequency and period source is AC voltage INBUF OFF Disable input buffer LOCK OFF Keyboard enabled MATH OFF Disable real time math MEM OFF Disable reading memory MFORMAT SREAL Single real reading memory format MMATH OFF Disable post process math NDIG 6 Display 6 5 digits NPLC 1 1 power line cycle of integration time NRDGS 1 AUTO 1 reading per trigger auto sample event OCOMP OFF Disable offset compensated ohms OFORMAT ASCII ASCII output format TARM AUTO Auto trigger arm event TIMER 1 1 second timer interval TRIG SYN Synchronous trigg
345. me PRINT USING 44A DD DDD The total time for DEFEAT ON is Exe time Dnld_timet Tns_ time PRINT ND UB Default REAL Dnld_time Exe time Tns_ time IM A 37 xe_time T1MEDATE UTPUT 722 RESET TRIG SYN UTPUT 722 0OHM T023 R 722 A I O ve H N1 GH ix H H PUT 722 OHMF 722 A 24 NTER 722 A 25 UTPUT 722 ACV NTER 722 A 26 NTER 722 A 27 UTPUT 722 DCV 28 TO 33 R 722 A 1 a J pi U A w H zZz oO x HD H m H UTPUT 722 ACV NTER 722 A 34 UTPUT 722 DCV 35 TO 37 NTER 722 A T NEXT Exe_time TIMEDATE Exe_time Dnld time 0 Tns_time 0 UBEND UB Fixed REAL Dnld_time Exe time Tns_ time IM A 37 xe_time TIMEDATE UTPUT 722 RESET TRIG SYN UTPUT 722 OHM 1E4 I 1 TO 15 NTER 722 A T O w H H a O ELO A O A O A eO a e a O O Pr ia S S D E O O E E N OUTPUT 722 OHM 1E5 FOR I 16 TO 23 ENTER 722 A 1 N OUTPUT 722 OHMF 1E3 ENTER 722 A 24 ENTER 722 A 25 OUTPUT 722 ACV 250 ACBAND 250 ENTER 722 A 26 OUTPUT 722 ACV 10 ACBAND 25000 ENTER 722 A 27 340 Appendix D Optimizing Throughout and Reading Rate 030 040 050 060 070 080 090 00 10 20 30 40 50 60 70 80 90 200 210 220 230 240 250 260 270 280 290 300 310 320 330 340 350 360 370 380 390 10 20 30 40 50 60 70 80 Kop BAS Bo Ws 500 510 520 530 540 550 560 570 580 590 600 610 620 630 640 650 66
346. measurement method remains in effect until power is cycled the multimeter is reset or another method is specified Whenever you select AC or AC DC voltage measurements the last specified or power on measurement method will be used The multimeter measures current by placing an internal shunt resistor across the input terminals measuring the voltage across the resistor and calculating the current current voltage resistance Unlike AC or AC DC voltage measurements AC or AC DC current measurements can be made using the analog method direct integration only The multimeter s front and rear current inputs are protected by 1 A 250V fuses Figure 12 shows the front terminal connections for all types of current measurements The multimeter measures AC or AC DC current on any of five ranges For AC current measurements the multimeter measures only the AC component of the input signal For AC DC current measurements the multimeter 64 Chapter 3 Configuring for Measurements measures the DC component and the AC component with frequencies gt 10Hz Notice that when measuring AC DC current any AC components below 10Hz are not included in the measurement The maximum resolution for AC or AC DC current is 6 digits Table 16 shows each current range and its full scale reading maximum resolution and the shunt resistor used Resolution is a function of the specified integration time refer to Setting the Integration Time later in this section
347. mes may contain up to 10 characters The first character must be a letter A Z but the remaining nine characters can be letters numbers 0 9 the underscore character _ or the question mark Subprogram names must not be the same as 3458A commands or parameters previously defined array or variable names or stored state names The following program shows how to create a simple subprogram which configures the multimeter to make three dc voltage measurements 10 OUTPUT 722 SUB DMM CONE 20 OUTPUT 722 DCV8 0 00125 30 OUTPUT 722 NRDGS 3 40 OUTPUT 722 TRIG SGL 50 OUTPUT 722 SUBEND 60 END The two statements SUB DMM_CONF and SUBEND along with the three commands on line 20 30 and 40 form the subprogram named DMM _ CONF When a subprogram is entered the 3458A checks for syntax errors just like any other commands If the syntax is not correct an error is generated and the command is not stored in the subprogram You must then edit your subprogram in the system controller and download it again The 3458A stores the subprogram in non volatile memory You can then execute the subprogram from either the front panel keyboard or the system controller Chapter 7 BASIC Language for the 3458A The subprogram will not be stored if a subprogram nesting error exists when the SUBEND command is executed e g if one of the called subprograms does not exist in 3458A memory If you create or download a subprogram using a su
348. mmediately after the readings made e You should not use the SINT or DINT output or memory format for frequency or period measurements when a real time or post process math function is enabled except STAT or PFAIL or when autorange is enabled Related Commands OFORMAT SSAC SSDC SINT Example The following program outputs 10 readings in SINT format retrieves the scale factor and multiplies the scale factor times each reading 10 OPTION BASE COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Int_rdgs 1 10 BUFFER CREATE INTEGER BUFFER ARRAY 30 REAL Rdgs 1 10 CREATE REAL ARRAY 40 Num_readings 10 NUMBER OF READINGS 10 50 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 60 ASSIGN Int_rdgs TO BUFFER Int_rdgs ASSIGN BUFFER I O PATH NAME 70 OUTPUT Dvm PRESET NORM OFORMAT SINT NPLC 0 NRDGS Num_readings 75 TARM AUTO TRIG SYN SINT OUTPUT FORMAT IN INTEGRATION TIME 80 TRANSFER Dvm TO Int_rdgs WAIT SYN EVENT TRANSFER READINGS INTO 81 INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS 85 SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED 90 OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR SINT FORMAT 00 ENTER Dvm S ENTER SCALE FACTOR 10 FOR I 1 TO Num_readings 20 Rdgs I Int_rdgs I CONVERT EACH INTEGER READING TO REAL 25 FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEXT LINE 30 R ABS Rdgs I LUSE ABSOLUTE VALUE TO CHECK FOR OVLD 40 IF R gt
349. mplied read method of recalling readings Unlike the RMEM command the implied read removes readings from memory In the LIFO mode the most recent reading is returned In the FIFO mode the oldest reading is returned The following program makes 200 readings places them in reading memory and uses the implied read to transfer the readings to the controller Chapter 4 Making Measurements 97 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 200 DIMENSION ARRAY FOR 200 READINGS 30 OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 NRDGS 200 AUTO 1200 READINGS TRIGGER AUTO SAMPLE EVENT 50 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 60 OUTPUT F227 TRIG SGL TRIGGER READINGS 70 PAUSE PAUSE PROGRAM PRESS CONTINUE TO RESUME 80 ENTER 722 Rdgs ENTER READINGS 90 PRINT Rdgs PRINT READINGS 100 END Sending Readings Across the Bus 98 Output Formats Note This section describes the output formats for readings and how to transfer readings from the multimeter to the controller The multimeter sends readings to the GPIB output buffer whenever readings are being taken and reading memory is not enabled MEM OFF command In thepower on RESET or any of the PRESET states reading memory is not enabled The five output formats and the number of bytes per reading are ASCII na 15 bytes per reading SINT za 2 per reading DINT na 4 bytes per reading SREAL gt 4 b
350. n disables autoranging Power on control ON Default control ON e With autorange enabled the multimeter samples the input signal before each reading and selects the appropriate range e Refer to the FUNC or RANGE command for a listing of the ranges for each measurement function e Autorange does not operate for direct or sub sampled measurements DSAC DSDC SSAC or SSDC command or when using the TIMER sample event or the SWEEP command Query Command The ARANGE query command returns a response indicating the present autorange mode Refer to Query Commands near the front of this chapter for more information Related Commands FUNC RANGE OUTPUT 722 ARANGE OFF DISABLES AUTORANGE AUXERR Syntax Auxiliary Error When a hardware error is detected the multimeter sets a bit in the auxiliary error register The AUXERR command returns a number representing the decimal weighted sum of all set bits The register is then cleared AUXERR Auxiliary Error The auxiliary error conditions and their weighted values are Conditions Weighte Bit d Value Number Description 1 0 Slave processor not responding 2 1 DTACK failure 4 2 Slave processor self test failure 8 3 Isolator test failure Chapter 6 Command Reference 161 AZERO AZERO Remarks Example Syntax Weighte Bit d Value Number Description 16 4 A D converter convergence failure 32 5 Calibration value out of range 64
351. n a fixed range Chapter 4 Making Measurements Note Overload Indication Output Termination Using the SINT or DINT Output Format SINT Example When using the SINT or DINT memory output format the multimeter applies a scale factor to the readings The scale factor is based on the multimeter s measurement function range A D converter setup and enabled math operations You should not use the SINT or DINT format for frequency or period measurements when a real time or post process math operation is enabled except STAT or PFAIL or when autorange is enabled e Single Real SREAL or Double Real DREAL Unlike the SINT and DINT formats readings output in SREAL or DREAL format are not scaled and can be used with any measurement function multimeter configuration Since there is no scale factor the SREAL and DREAL formats are ideal when autoranging and or a math function is enabled The DREAL format has the added advantage that no conversion is necessary by the controller Use the SREAL format for measurements with lt 6 5 digits of resolution Use the DREAL format for measurements with gt 6 5 digits of resolution The OFORMAT command specifies the output format for readings the power on and default format is ASCII For example to select the double integer format send OUTPUT 722 OFORMAT DINT The multimeter indicates an overload condition input greater than the present range can measure by outputting the larg
352. n alphanumeric name the first character must be alpha Alpha or alphanumeric state names must not be the same as multimeter commands or parameters or the name of a stored subprogram When using an integer state name the multimeter assigns the prefix STATE to the integer when the state is stored This differentiates an integer state name from an integer subprogram name For example a state stored with the name 8 will be recorded as STATES The state can be recalled later using either the name 8 or STATES All states are stored in continuous memory remain intact when power is removed The multimeter compiles the state as it is stored This means that when the state is recalled the multimeter configures itself much faster than could be done by executing the individual commands that were used to create the state To store the present multimeter state as a state named ACST1 send OUTPUT 722 SSTATE ACST1 Recalling States The RSTATE command recalls a state from memory and configures the multimeter to the recalled state For example to recall state ACSTI send 74 Chapter 3 Configuring for Measurements OUTPUT 722 RSTATE ACST1 From the front panel you can view all stored state names by accessing the RSTATE command and pressing the up or down arrow key Once you have found the correct state press Enter to recall the state Deleting States You can delete a single stored state using the PURGE command For example to purge the sta
353. n be cleared with the DELSUB command Individual states can be cleared with the PURGE command Related Commands DELSUB PURGE RSTATE SSTATE SUB OUTPUT 722 SCRATCH CLEARS ALL SUBPROGRAMS AND STORED STATES Security Code Allows the person responsible for calibration to enter a security code to prevent accidental or unauthorized calibration or autocalibration autocal Refer to the ACAL command for details on autocal SECURE old_code new_code acal_secure old_code This is the multimeter s previous security code The multimeter is shipped from 232 Chapter 6 Command Reference SETACV Remarks Examples Syntax SETACV the factory with its security code set to 3458 new_code This is the new security code The code is an integer from 2 1E9 to 2 1E9 If the number specified is not an integer the multimeter rounds it to an integer value acal_secure Allows you to secure autocalibration The choices are Numeric acal_secure Query Parameter Equiv Description OFF 0 Disables autocal security no code required for autocal ON 1 Enables autocal security the security code is required to perform autocal see ACAL for example Power on acal_ secure Previously specified value ON is the factory setting Default acal_secure OFF Specifying 0 for the new_code disables the security feature making it no longer necessary to enter the security code to perform a calibration or autocal The front pane
354. n called and executed bit 0 is set in the status register program memory execution completed This asserts a GPIB SRQ enabled by line 30 and causes a pulse on the Ext Out connector specified by line 40 This pulse signals external equipment that the multimeter is configured and ready to make measurements 722 SUB EXTSRQ 722 PRESET NORM 7225 ROS 1 722 EXTOUT SRQ POS 722 OHMF 10E3 722 NPLC 100 722 OCOMP ON 7227 IRIG EXT 722 MATH CTHRM10K OUTPUT 722 CSB OUTPUT 722 SUBEND OUTPUT 722 CALL EXTSRQ END STORE SUBPROGRAM NAMED EXTSRQ PRESET TRIG SYN TARM AUTO NRDGS 1 AUTO ENABLE SUBPROGRAM EXECUTION COMPLETE BIT SRQ EXTOUT EVENT HI GOING PULSE 2 WIRE OHMS 10kQ RANGE 100 PLCS INTEGRATION TIME ENABLE OFFSET COMPENSATION EXTERNAL TRIGGER EVENT ENABLE 10kQ rT HERMISTOR MATH OPERATION CLEAR STATUS REGISTER END OF SUBPROGRAM CALL SUBPROGRAM Executing the EXTOUT ONCE command produces a single 1uS pulse on the multimeter s Ext Out connector After executing EXTOUT ONCE the mode reverts to OFF the EXTOUT signal is disabled As shown in the following program EXTOUT ONCE is useful in subprograms to indicate the completion of the subprogram or a segment of the subprogram to external equipment EXTONCE UT ONCE ET FAST FIFO S20 SGL UT ONCE P ON E3 GS 40 L EXTONCE 10 OUTPUT 722 SUB 20 OUTPUT 722 EXTO 25
355. n measuring AC DC voltage using the analog method for example any AC components below 10Hz are not included in the measurement When taking measurements on the 10mV and 100mV ranges using any AC measurement method it is possible for radiated noise such as transients caused large motors turning on and off to cause inaccurate readings For accurate readings on these ranges ensure that your nearby environment is electrically quiet and use shielded test leads Table 15 AC and AC DC Voltage Measurement Methods ACV ACDCV Readings Per Measurement Repetitive Signal Second Method Frequency Range Best Accuracy Required Min Max Synchronous 1 Hz 10MHz 0 01 Yes 0 025 10 Analog 10 Hz 2MHz 0 03 No 0 8 50 Random 20 Hz 10MHz 0 10 No 0 025 45 Synchronous Sampling The synchronous sampling conversion calculates the true RMS value from Conversion Synchronous Sampling Remarks samples but requires that the input signal be repetitive periodic Synchronous sampling has excellent linearity and is the most accurate of the three methods Synchronous sampling is useful for measuring periodic waveforms in the frequency range of 1 Hz to 10 MHz For synchronous sampling the multimeter uses the LEVEL sync source event default mode to synchronize sampling to the input signal If the input signal is removed during areading and does not return within a certain amount of time the time limits are determin
356. n resistance only not the combined resistance This is important when the test lead resistance is high in comparison to the resistance being measured Figure 14 shows the front connections for 4 wire ohms measurements You specify 4 wire ohms measurements using the OHMF command For example to specify 4 wire ohms measurements on the 10OMQ range send OUTPUT 722 OHMF 10E6 Chapter 3 Configuring for Measurements 57 CURRENT FLOW TO ie MEP F 3 4 Figure 14 4 Wire ohms measurement connections Configuring the A D Converter The Reference Frequency Changing the Reference Frequency The A D converter s configuration determines the measurement speed resolution accuracy and normal mode rejection for DC or ohms measurements The factors that affect the A D converter s configuration are the reference frequency the specified integration time and the specified resolution When power is applied the multimeter measures the power line frequency rounds the value to 50 Hz or 60 Hz and sets the A D converter s reference frequency to the rounded value For a 400Hz power line frequency the multimeter uses 50Hz as the reference frequency which is a subharmonic of 400Hz For DC or ohms measurements the multimeter achieves normal mode rejection NMR for noise at the reference frequency when the integration time is 1 power line cycle See Setting the Integration Time following for more informati
357. n the specified resolution To ensure the fastest triggering configuration set the trigger arm trigger and sample events to AUTO You can also use the TIMER sample event or the SWEEP command Assuming you do not generate the TRIGGER TOO FAST error the reading rate is the reciprocal of the TIMER or SWEEP interval Under normal operation the multimeter automatically determines a delay time default delay based on the present measurement function range resolution and for AC measurements the AC bandwidth setting This delay time is actually the settling time inserted before the first reading which ensures accurate readings The default delay has a large affect on the reading rate for analog AC measurements and a minimal affect on the reading rate for sampled AC voltage or DC measurements For analog AC measurements you can achieve a faster reading rate by specifying a shorter delay than the default value However the resulting settling time may not produce accurate measurements For the fastest AC measurements specify the AC bandwidth ACBAND command to match the frequency content of the input signal The specifications in Appendix A show the reading rates for AC measurements based on the frequency components of the input signal For 2 and 4 wire ohms measurements with offset compensation enabled an offset voltage measurement is made before each resistance reading This requires more time than with offset compensation disabled OCO
358. n without the aid of automatic program generators can be so structured Program generators are usually optimized for ease of programming and offer a simplistic approach to the testing task that lets you choose limits for each group of tests but do not necessarily group the tests for the fastest throughput Functional test management software like the FTM300 allows the tests to be customized for 322 1 GPIB is an implementation of the IEEE Standard 488 and the identical ANSI Standard MC1 1 Digital interface for programmable instrumentation Appendix D Optimizing Throughout and Reading Rate throughput and still provides 70 of the overhead programming like Statistical Quality Control SQC and inventory management System U ptime Longer system up time also means higher test system throughput The 3458A s Multimeter performs a complete self calibration of all functions including AC using high stability internal standards This self or auto calibration eliminates measurement errors due to time drift or temperature changes in your rack or on your bench for superior accuracy When it s time for periodic calibration to external standards simply connect a precision 10 V DC source and a precision 10 kQ resistor All ranges and functions including AC are automatically calibrated using precision internal ratio transfer measurements relative to the external standards The subject of calibration is treated in detail in Product Note 3458A 3 A sy
359. nabled math operations It then multiplies the scale factor by the stored reading and sends the result recalled reading to the display or the output buffer Therefore always ensure that the multimeter s configuration is the same when storing and recalling data in the SINT or DINT format You should not use the SINT or DINT output or memory format for frequency or period measurements when a real time or post process math function is enabled except STAT or PFAIL or when autorange is enabled The memory format does not affect the output format specified by the OFORMAT command You enable reading memory using the MEM command You access stored readings using the RMEM command or by using the implied read The implied read is discussed under Using Reading Memory in Chapter 4 When using reading memory for sub sampled measurements SSAC or SSDC command the memory format must be set to SINT the memory mode must be Chapter 6 Command Reference 199 MMATH MMATH Example Syntax FIFO MEM FIFO command and reading memory must be empty done by executing the MEM FIFO command before samples are taken If these requirements are not met when the trigger arm event occurs an error is generated Query Command The MFORMAT query command returns the present memory format Refer to Query Commands near the front of this chapter for more information Related Commands MCOUNT MEM MSIZE RMEM 10 OUTPUT 722 NPLC 10 10 PL
360. nction DSP string or user_variable Outputs to the multimeter s front panel display both text and user variable data available only in REV 2 1 firmware and greater DSP Reads the present front panel display SCROLL LEFT RIGHT Scrolls the present front panel display one character to the left or right This applies only to text sent with the DISP command for more information see chapter 6 ECHO string Echoes the specified string back to either the multimeter s front panel display or GPIB The data is sent to either to the display or GPIB output buffer based on the source from which the subprogram was executed RETURN Used in a subprogram to return before the SUBEND statement RMATHYV register user_variable Reads a standard multimeter math register into a user variable available only in REV 5 1 firmware and greater WAIT msec Wait before executing the next command 32 seconds maximum Chapter 7 BASIC Language for the 3458A 3458A BASIC Language Example Program The following example program illustrates the use of the 3458A s internal BASIC language along with the use of new multimeter commands This program example uses a Series 300 BASIC computer for program development and for downloading the program to the multimeter over the GPIB interface The multimeter s bus address is 22 and the computer s GPIB interface address is set to 700 10 20 30 40 50 60 70 80 90 00 10 20 30 40 50 60 70 80 90 200 21
361. nd Line 40 specifies 8 readings per trigger event Figure 19 shows that the delay occurs between the trigger event TRIG SGL and the first reading The SWEEP interval then occurs between each successive reading In this example the amount of time added to the total measurement is 9 seconds 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 8 IDIMENSION ARRAY FOR READINGS 30 OUTPUT 722 PRESET NORM ITARM AUTO TRIG SYN DCV AUTORANGE 40 OUTPUT 722 SWEEP 1 8 1 SECOND INTERVAL 8 READINGS TRIGGER 50 OUTPUT 722 DELAY 2 2 SECOND DELAY 60 ENTER 722 Rdgs IENTER READINGS 70 PRINT Rdgs PRINT READINGS 80 END Chapter 4 Making Measurements 2 SEC 1 SEC 1 SEC 1 SEC 1 SEC 1 t SEC 1 SEC DELAY TIMER TIMER TIMER TIMER bet lau TIMER l bt Ld Et eg RIG SYN RDG pr ae i Ag beg RDO Ka OCCURS 1 Figure 19 DELAY with SWEEP or TIMER Default Delays Ifyou have not specified a delay interval the multimeter automatically determines a delay time default delay time based on the present measurement function range resolution and the AC bandwidth setting This delay time is actually the settling time allowed before readings which ensures accurate measurements The default delay time is updated automatically whenever the function range resolution or AC bandwidth changes However once you specify a delay time value the value does not change until you execute RESET or a PRESET command cycle
362. nd This is useful to prevent a change in input resistance caused by changing ranges from affecting the measurements Table 12 shows the input resistances with FIXEDZ OFF With FIXEDZ ON the input resistance is a constant 10 MQ for all DC voltage ranges In the poweron PRESET NORM state fixed resistance is disabled OFF To enable fixed resistance send OUTPUT 722 FIXEDZ ON To disable fixed resistance send OUTPUT 722 FIXEDZ OFF Configuring for AC Measurements AC or AC DC Voltage This section describes how to configure the multimeter for making AC or AC DC voltage AC or AC DC current frequency or period measurements The multimeter can make true RMS AC voltage or AC DC voltage measurements using one of three methods analog RMS conversion random sampling conversion or synchronous sampling conversion Each measurement method has six ranges 10mV 100mV 1V 10V 100V and 1000V and a maximum resolution of 64 digits on any range Table 15 shows the measurement characteristics and signal requirements for each measurement method Figure 11 shows the front terminal connections for all types of voltage measurements For AC voltage measurements the multimeter measures only the AC component of the input signal For AC DC voltage measurements the multimeter measures the DC component and the AC component within the 62 Chapter 3 Configuring for Measurements Note frequency ranges shown in Table 15 Notice that whe
363. nd or the SWEEP command SWEEP is the simpler to program The NRDGS and SWEEP commands are interchangeable the multimeter uses whichever command was specified last When using the SWEEP command the sample event is automatically set to TIMER For direct sampling you should use the SINT memory output format when the peak value of the input signal is lt 120 of the specified range Use the DINT memory output format when the input signal is gt 120 of the range SINT and DINT are the formats used internally by the A D converter by using the correct Chapter 6 Command Reference 173 EMASK EMASK Example Syntax value memory output format no format conversions are necessary Related Commands DSDC FUNC LEVEL LFILTER SLOPE NRDGS PRESET FAST PRESET DIG SSAC SSDC SSPARM SWEEP TARM TIMER TRIG The following program is an example of DC coupled direct sampled digitizing The SWEEP command specifies an interval of 30us and 200 samples Level triggering is set for 250 of the 10V range 250 of 10V 25V The samples are sent to reading memory in DINT format The samples are then sent to the controller converted and printed By deleting line 110 samples will be transferred directly to the controller instead of using reading memory However the controller and GPIB must be able to transfer samples at a rate of at least 134k bytes second or the multimeter will generate the TRIGGER TOO FAST error Refer to High Sp
364. nd the 3458A checks to see if a subprogram by that name exists in memory If not it generates an error Second subprograms may not be nested more than 10 levels deep You cannot place one subprogram inside of another subprogram For example the following program will generate an error 10 OUTPUT 722 SUB DMM_ CONE 20 OUTPUT 722 DCV8 0 00125 30 OUTPUT 722 SUB TESTER This results in an error 40 OUTPUT 722 SUBEND SOl 60 OUTPUT 722 CALL DMM_CONF 70 END Conditional Statements in Subprograms 278 FOR NEXT Loops The 3458A provides three BASIC language statements for conditional branching and looping Use these statements only within 3458A subprograms Conditional branching and looping statements provide for repetitive tests initializing arrays etc The three conditional statements are FOR NEXT WHILE ENDWHILE and IF THEN These statements are similar to those used in an enhanced BASIC language The only exception is that 3458A subprograms do not have line numbers or GOTO statements for branching Looping and conditional branching statements may be nested seven deep The FOR NEXT command defines a loop which is repeated until a loop counter passes a specified value The syntax statement for the FOR NEXT Chapter 7 BASIC Language for the 3458A WHILE Loops command is shown below FOR counter initial_value TO final_value STEP step_size program segment NEXT counter The counter parameter
365. nel these keys are labeled fO f9 After assigning one or more commands to a key pressing that key displays the command s on the multimeter s display Pressing the Enter key will then execute the command s in the order listed The DEFKEY DEFAULT command erases the strings assigned to all user defined keys DEFKEY number string or DEFKEY DEFAULT The number parameter is an integer in the range 0 9 or FO F9 that designates the particular function key Power on number none Default number 0 The string parameter is the command or list of commands to be assigned to the function key Link multiple commands with a semicolon The string parameter must be enclosed in single or double quotes The maximum string length is 40 characters the quotes enclosing the string are not counted as characters Power on string none Default string none clears any previous string DEFAULT Erases the strings assigned to all user defined keys Key definitions stored from the front panel can be edited from the front panel Definitions stored from remote cannot be edited e You cannot embed quotes in the DEFKEY string This means you cannot use the DISP command with a message in quotation marks as a string parameter You can however use the DISP command and an unquoted message refer to the DISP command for limitations on unquoted messages Query Command The DEFKEY query command returns the string parameter currently assigne
366. nes up with the screw hole in the chassis Use the TX 10 Torx driver to reinstall the shield screw Front Rear If you DO NOT wish to lockout the Front Rear Terminal switch continue with Pushrod Removal next paragraph Procedure 1 Refer to Figure 41 Turn the instrument over so its bottom sits on your work bench 2 Use the TX10 Torx driver to remove the top shield screw Then remove the shield Pull the shield toward the rear of the instrument until the shield retainers line up with the slots in the shield Lift the shield off 314 Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches BOTTOM SHIELD SCREW Figure 39 3458 Inside bottom view GUARD SWITCH PUSHROD o pw i an e SS Figure 40 Guard switch and pushrod location Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches 315 aa Bienen t Figure 41 3458 Inside top view 3 Refer to Figure 42 Locate the pushrod for the Front Rear Terminal switch Pull the pushrod off You may need to pry the pushrod loose with a small flat blade screwdriver Set the switch in the position it is to be used 4 Refer to Figure 41 Replace the top shield Line up the slots on the shield with the shield retainers Then push the shield toward the front of the instrument until the shield screw hole lines up with the hole in the chassis Use the TX 10 Torx driver to reinstall the shield screw Switch Cap Do
367. ng an error bit prevents it from setting the error bit in the status register only and thereby generating a service request Query Command The EMASK query command returns the weighted sum of all enabled error conditions see example below Related Commands AUXERR ERR ERRSTR RQS STB OUTPUT 722 EMASK 4 5 ENABLES THE TRIGGER TOO FAST ERROR OUTPUT 722 EMASK 248 ENABLES ERRORS 8 16 32 64 AND 128 OUTPUT 722 EMASK 0 DISABLES ALL ERRORS 10 OUTPUT 722 EMASK RETURNS EMASK VALUE 20 ENTER 722 A ENTER RESPONSE 30 PRINT A PRINT VALUE 40 END Chapter 6 Command Reference 175 END END The END command enables or disables the GPIB End Or Identify EOI function Syntax END control control The control parameter choices are Numeric control Query Parameter Equiv Description OFF 0 EOI line never set true ON 1 For multiple readings SWEEP or NRDGS gt 1 the EOI line is set true with the last byte of the last reading sent For single readings EOI line set true with the last byte of each reading ALWAYS 2 EOI line set true when the last byte of each reading sent Power on control OFF Default control ALWAYS Remarks Each reading output to the GPIB in ASCII format is normally followed by cr f carriage return line feed The cr f indicates the end of transmission to most controllers Readings output in any other format do not have the cr fend of line sequence When u
368. ng general safety precautions must be observed during all phases of operation service and repair of this product Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design manufacture and intended use of the product Keysight Technologies assumes no liability for the customer s failure to comply with these requirements Ground the equipment For Safety Class 1 equipment equipment having a protective earth terminal an uninterruptible safety earth ground must be provided from the mains power source to the product input wiring terminals or supplied power cable DO NOT operate the product in an explosive atmosphere or in the presence of flammable gases or fumes For continued protection against fire replace the line fuse s only with fuse s of the same voltage and current rating and type DO NOT use repaired fuses or short circuited fuse holders Keep away from live circuits Operating personnel must not remove equipment covers or shields Procedures involving the removal of covers or shields are for use by service trained personnel only Under certain conditions dangerous voltages may exist even with the equipment switched off To avoid dangerous electrical shock DO NOT perform procedures involving cover or shield removal unless you are qualified to do so DO NOT operate damaged equipment Whenever it is possible that the safety protection features built into this product have
369. nimum time for the measurement with sufficient accuracy there is yet another factor to consider to improve test throughput task allocation This factor involves the controlling computer and other instrumentation in the system As stated in the introduction to this product note for the most part the fastest instrument in the test system is the dmm Hence its measurement rate may not be the throughput bottleneck in the system One can take advantage the high speed measurement capability of the 3458A by letting it compute its own statistics linearize its own thermistors or check its own limits while the controller is controlling other instrumentation or is otherwise busy The features of the 3458A dmm that make this possible are the built in math functions the Reading Memory State Memory and Program Memory The time necessary to transfer measurements and commands to the computer is computer dependent GPIB turnaround time the time to process OUTPUT and ENTER operations will vary considerably from computer to computer The features of Program Memory Reading Memory State Storage and post processing math operations all tend to decrease GPIB overhead and make the testing time far less computer dependent Optimizing the Testing Process Through Task Allocation Math Operations Data Storage Individually math operations performed within the 3458A slow the measurement speed of the 3458A but many times the combination of the 3458A with the co
370. nized in time with the input signal Chapter 5 Digitizing 141 INPUT SIGNAL SYNCHRONIZING SIGNAL 5V OV Figure 33 Typical synchronizing signal for EXT sync source The LEVEL sync source event which is the power on default sync source event occurs when the input signal reaches a specified voltage level on the specified slope level triggering Figure 31 shows the operation of the LEVEL sync source event for this example the LEVEL is specified as 0 positive slope AC coupling The first sync source event occurs when the input signal crosses 0V with a positive slope The multimeter then takes a burst of samples 5 samples in this case Following the next occurrence of the sync source event period 2 of the input signal the multimeter delays the trigger point and takes 5 more samples This process repeats until the specified number of samples are completed In the following example the SSDC command is used to digitize a 1 MHz signal with a peak value of 5V riding on a 5V DC level The SWEEP command instructs the multimeter to take 4000 samples with a 10 nanosecond effective_interval Lines 60 through 80 program the voltage level and the slope for the LEVEL sync source event This will initiate sampling when the first period of the input signal reaches 7 5 VDC 75 of the 10V range Line 90 satisfies the trigger arm event which essentially enables the sync source event LOOUTPUT 722 PRESET FAST TARM SYN TRIG A
371. ns_time PRINT CALL Disp Dnld_time Exe time Tns_time B RINT USING 44A DD DDD The execution time for program memory is Exe_time PRINT USING 44A DD DDD The download time for transfering the SUB is Dnld_time PRINT USING 44A DD DDD The transfer time using FOR NEXT is Tns_ time PRINT USING 44A DD DDD The total time for display off is Exe time Dnld_timetTns_time PRINT l CALL Azero Dnld_time Exe_time Tns_time PRINT USING 44A DD DDD The execution time for program memory is Exe_time PRINT USING 44A DD DDD The download time for transfering the SUB is Dnld_time Appendix D Optimizing Throughout and Reading Rate 339 60 70 80 90 SoS Bos 500 510 520 530 540 550 560 570 580 590 600 610 620 630 640 650 660 670 680 690 700 710 720 730 740 750 760 EDD 780 790 800 810 820 830 840 850 860 870 880 890 900 910 920 930 940 950 960 970 980 990 1000 1010 1020 PRINT USING 44A DD DDD The transfer time using FOR NEXT is Tns_time PRINT USING 44A DD DDD The total time for AZERO off is Exe_time Dnld_timet Tns_time i my w NT CALL Defeat Dnld_time Exe _time Tns_time PRINT USING 44A DD DDD The execution time for program memory is Exe_time PRINT USING 44A DD DDD The download time for transfering the SUB is Dnld_time PRINT USING 44A DD DDD The transfer time using FOR NEXT is Tns_ ti
372. nt 3 1 C but within 5 C of Coefficient last ACAL 10 mV 0 0 0 2 0 0 015 0 15 3 0 0 06 of Reading of 100 mV 1000 V 0 0 0 02 0 0 001 0 15 0 25 0 0 007 Range C Additional Errors Apply the following additional errors as appropriate to your particular messuepePaceError of LOW Frequency Error of Reading Reading ACBAND Low Crest Additional 10 Hz 1 kHz 1 10 kHz gt 10 kHz Factor Error Signal Frequency NPLC gt 10 NPLC gt 1 NPLC gt 0 1 1 2 0 10 200 Hz 0 2 3 0 15 200 500 Hz 0 0 15 500 1 kHz 0 0 015 0 9 3 4 0 25 1 2 kHz 0 0 0 2 4 5 0 40 2 5 kHz 0 0 0 05 5 10 kHz 0 0 0 01 290 Appendix A Specifications Reading Rates Sec Reading ACBAND Low NPLC ACV ACDCV 210 Hz 10 1 2 1 21 kHz 1 1 0 1 210 kHz 0 1 1 0 02 Settling Characteristics For first reading or range change error using default delays add 01 of input step additional error The following data applies for DELAY 0 Function ACBAND Low DC Component Settling Time ACV gt 10 Hz DC lt 10 AC 0 5 sec to 0 01 DC gt 10 AC 0 9 sec to 0 01 ACDCV 10 Hz 1 kHz 0 5 sec to 0 01 1 kHz 10 kHz 0 08 sec to 0 01 210 kHz 0 015 sec to 0 01 Maximum Input Related Input Non Destructive HI to LO LO to Guard 4 Common Mode Rejection 1000 V pk 1200 V pk Guard to Earth 4 Volt Hz Product 1 x 108 Random Sampled Mode ACV Function SETACV RNDM For 1 kQ imbalance in LO lead gt 90 dB
373. ntheses following each command title All syntax statements and examples assume an interface select code of 7 and the device address of 22 Table B I shows the multimeter s GPIB capabilities IEEE 488 1 Function Source Handshake Table 29 GPIB Capabilities Code SH1 Description Allows the multimeter to properly transfer multiline messages Acceptor Handshake AH1 Allows the multimeter to guarantee proper reception of multiline messages Talker T5 Allows the multimeter to be a talker which means it can send data over the GPIB This also allows the multimeter to respond to serial poll Listener L4 Allows the multimeter to be a listener which enables it to receive information over the GPIB Service Request SR1 Allows the multimeter to asynchronously send a service request to the controller Remote Local RL1 Allows the multimeter to be programmed over the GPIB or from its front panel Parallel Poll PPO No capability Device Clear DC1 Allows the multimeter to be initialized to a cleared state by the Device Clear command issued from the controller Device Trigger DT1 Allows the multimeter to be triggered over the GPIB Controller Function CO No capability Driver Electronics E2 Describes the electrical drivers used by the multimeter E2 tri state 1MByte second max Appendix B GPIB Commands 303 ABORT 7 IFC ABORT 7 IFC Syntax Example Clears the multimeter s interface
374. ntial Parameters ccseeeeeeneeeees 35 Multiple Parameters ccccccesccesseeseeeteeees 35 Using the MENU Keys eeeeccecseeteeteeereeenes 36 Query Commands ceccceccceseeteeeteeeteenteeetnees 37 Standard Queries cccccsceessesesseceseeeetseees 37 Additional Queries ccccccccsssceeseeeeeeeees 37 Display Control 0 ceeeecceseeeeeeceeteeeecneeeeeeneenees 37 Clearing the Display ccccecccesseeseeeteeees 37 Display Editing eeceeeeeeeeeeeeceeeeeeeenees 38 Viewing Long Displays e ceeseseeseerees 38 MORE INFO Display ccccscesseesceeeeeeees 39 Digits Displayed 0 0 0 eeceeseeeeceeteeteceeeeeeeeeeeees 39 Real cece inani ana ana a aan 39 User Defined Keys cccceccecsesseeseceseeeeeeeeeesees 40 Installing the Keyboard Overlay cee 41 Operating from Remote cceeceeseeseceteceteeeeeeees 42 Input Output Statements sseseiseeeeeee seses 42 Reading the GPIB Address 0 eeeeeeeeeereeeee 42 Changing the GPIB Address 43 Sending a Remote Command cece 43 Getting Data from the Multimeter 0 0 0 0 43 Phe Local Key tus sertoesiidisis abel aa a 44 Chapter 2 Getting Started 23 24 Chapter 2 Getting Started Chapter 2 Getting Started Introduction This chapter is intended for the novice multimeter user It shows you how to use the multimeter s front panel how to send commands to the multimeter from remote and how to retrieve da
375. ntial increases in throughput can be achieved in test system requiring these measurements The 3458A provides this improved throughput by offering a wide range of alternatives that can improve Appendix D Optimizing Throughout and Reading Rate 321 the speed of testing For example in many systems accuracy can be traded for speed or flexibility in timing the measurement can lead to real increases in the rate of rms AC measurements with good accuracy The set of trade offs one may make with the 3458A Multimeter is covered in detail in this Product Note Maximizing the Testing Speed Program Memory State Storage Reading Analysis Task Grouping and Sequence The speed of the testing process can also be maximized by tailoring the communication path between the 3458A and the computer The dmm is generally the fastest instrument in the system hence to perform a series of measurements the computer may be compelled to take more time with other instruments Several features of the 3458A Multimeter allow the allocation of measurement tasks to be split optimally between the computer and the dmm Its unique non volatile Program Memory allows sequences of measurement to be performed dynamically using external events such as external auxiliary or GPIB triggers to step through the measurement sequence In addition using Program Memory complete measurement sequences can be programmed and initiated from the front panel for standalone operation
376. ntroller will perform faster together to achieve final answers if the 3458A does some of the math itself This is particularly true for pass fail limit checking where The computer is alerted only if the test has failed If statistics are important on the measurements then it is a simple matter to let the 3458A assume the task of computation instead of having to write a program on the controller The computer in the 3458A is a very powerful Motorola 68000 with a 8 MHz operating clock therefore many times it will have the same computational power that the controller has The memory of the 3458A can be used to store measurements for later transfer to the controller for up to 10 000 readings 20 kBytes Optionally one may use the Option 001 Expanded Memory and get an additional 65 000 reading 128 kBytes 330 Appendix D Optimizing Throughout and Reading Rate Output Formats State Storage and Program Memory storage The transfer rate into and out of the Reading Memory and the GPIB transfer rate using direct memory access with an HP 9000 Series 200 300 computer is 100 000 readings per second The advantage of the memory is that one may access the data when it is convenient for the controller and not have to tie the system up waiting for the measurement to finish a long integration period a long settling time or an average of multiple readings can cause even the fastest dmm to hold up the system The 3458A offers five different data formats
377. nts and then verifies the array size using the SIZE command 10 OUTPUT 722 INTEGER IARRAY 9 20 OUTPUT 722 SIZE IARRAY 30 ENTER 722 A 40 PRINT A 50 END Purging Arrays and All variables and arrays are stored in 3458A volatile memory If the 3458A Variables loses power all variables and arrays are lost The SCRATCH command also purges all variables arrays subprograms and stored state names stored states are explained in chapter 3 General Purpose Math You can use general purpose math expressions following standard BASIC language conventions from either the front panel keyboard the system controller or within 3458A subprograms The standard math operators Chapter 7 BASIC Language for the 3458A 269 Math Operators General Math Functions Logarithmic Functions 270 general math functions trigonometric functions and binary functions are available The 3458A also has a simple calculator mode In addition to the standard math operators two additional arithmetic operators exist in the 3458A These operators are DIV integer division and MOD modulo Unary minus operations should be written as A 0 B The DIV command returns the integer portion ofa division Normal division takes place but all digits to the right of the decimal point are truncated not rounded The following program divides 7 by 3 and displays the integer portion of the division 2 on the system controller 10 OUTPUT
378. o TIMER In the power on RESET or Chapter 6 Command Reference 255 TONE TONE TRIG Example Syntax Example Syntax PRESET state the multimeter uses the NRDGS command The power on values for SWEEP can only be used for sub sampling since NRDGS does not apply to sub sampling e You cannot use the TIMER or SWEEP event for AC or AC DC voltage measurements using the synchronous or random methods SETACV SYNC or RNDM or for frequency or period measurements Query Command The TIMER query command returns the present time interval in seconds for the NRDGS timer event Related Commands DELAY NRDGS SWEEP 10 OUTPUT 722 TRIG HOLD SUSPENDS MEASUREMENTS 20 OUTPUT 722 INBUF ON ENABLES THE INPUT BUFFER 30 OUTPUT 722 DCV 10 DC VOLTAGE 10V RANGE 40 OUTPUT 722 NPLC 1 SELECTS 1 PLC OF INTEGRATION TIME 50 OUTPUT 722 AZERO OFF DISABLES AUTOZERO 60 OUTPUT 722 MEM FIFO ENABLES READING MEMORY FIFO MODE 70 OUTPUT 722 TIMER 2 SELECTS 2 SECOND INTERVAL 80 OUTPUT 722 NRDGS 10 TIMER 10 READINGS PER SAMPLE EVENT TIMER 90 OUTPUT 722 TRIG SGL TRIGGERS ONCE 100 END Causes the multimeter to beep once The multimeter then returns to the previous BEEP mode either OFF or ON TONE Related Commands BEEP OUTPUT 722 TONE BEEPS Specifies the trigger event TRIG event event 256 Chapter 6 Command Reference Remarks Examples TRIG The event parame
379. oeesubpesteckt Eei 120 DBY re oraa a E Iie A 120 DEM T Ries ahaha 121 StAliStles giaa i o e a a e E OA 122 Pass Fail eaae e e 123 FILTER roeien eaaa e aa TASS 124 RMS E E aanita tema tats ts 125 Measuring Temperature cccceesseenteerees 125 Chapter 4 Making Measurements 79 80 Chapter 4 Making Measurements Chapter 4 Making Measurements Introduction This chapter discusses the methods for triggering measurements the reading formats how to use reading memory and how to transfer readings across the bus This chapter also discusses how to increase the reading rate and GPIB bus transfer speed how to measure the reading rate how to use the multimeter s EXTOUT signal and how to use the math operations Triggering Measurements Note TRIGGER ARM START i EVENT OCCURS Before the multimeter will take readings three separate events must occur in the proper order These events are 1 the trigger arm event 2 the trigger event and 3 the sample event Sub sampling discussed in Chapter 5 and multiple trigger arming discussed in this chapter are the only exceptions to this triggering hierarchy As shown in Figure 16 when all three events have occurred in the order listed the multimeter begins to make the specified reading s In the power on state the multimeter is configured so that it makes readings automatically that is all three events are set to AUTO For most applications you will need to use on
380. of Range ACBAND gt 2 MHz Range 45 Hz to 100 kHz 100 kHz to 1 MHz 1 MHz to 4 MHz 4 MHz to 8 MHz 8 MHz to 10 MHz 10 mV 0 09 0 06 1 2 0 05 7 0 07 20 0 08 100 mV 10 V 0 09 0 06 2 0 0 05 4 0 07 4 0 08 15 0 1 100 V 0 12 0 002 1000 V 0 3 0 01 Transfer Accuracy Range of Reading Conditions __ Oe Following 4 Hour warm up 100 mV 100 V_ 0 002 Resolution in e Within 10 min and 0 5 C of the reference measurement e45 Hz to 20 kHz sine wave input e Within 10 of the reference voltage and frequency AC DC Accuracy ACDCV Function For ACDCV Accuracy apply the following additional error to the ACV accuracy of Range DC lt 10 of AC Voltage Range ACBAND lt 2 MHz ACBAND gt 2 MHz Temperature Coefficient a 10 mV 0 09 0 09 0 03 100 mV 1000 V 0 008 0 09 0 0025 DC gt 10 of AC Voltage Range ACBAND lt 2 MHz ACBAND gt 2 MHz Temperature Coefficient 2 10 mV 0 7 0 7 0 18 100 mV 1000 V 0 07 0 7 0 025 Additional Errors Apply the following additional errors as appropriate to your particular measurement setup of Reading Input Frequency 3 Source R 0 1 MHz 1 4 MHz 4 8 MHz 8 10 MHz 02 0 2 5 5 Pract Paria Dachisiian E Crest Factor 50 QTerminated 0 003 0 0 0 Sosa Resolution Multpuer 75 QTerminated 0 004 2 5 5 12 Resolution in x 1 500 0 005 3 7 10 2 3 Resolution in x 2 3 4 Resolution in x 3 i 4 4 5 Resolution in x 5 Reading Rates ACBAND Lo
381. of the 3458A is determined by adding these relative accuracies to the traceability of your calibration standard For dcV 2 ppm is the traceability error from the Keysight factory That means that the absolute error relative to the U S National Institute of Standards and Technology NIST is 2 ppm in addition to the dcV accuracy specifications When you recalibrate the 3458A your actual traceability error will depend upon the errors from your calibration standards These errors will likely be different from the Keysight error of 2 ppm Example 1 Relative Accuracy 24 Hour Operating temperature is Tcal 1 C Assume that the ambient temperature for the measurement is within 1 C of the temperature of calibration Tcal The 24 hour accuracy specification for a 10 V dc measurement on the 10 V range is 0 5 ppm 0 05 ppm That accuracy specification means 0 5 ppm of Reading 0 05 ppm of Range For relative accuracy the error associated with the measurement is 0 5 1 000 000 x 10 V 0 05 1 000 000 x 10 V 5 5 uV or 0 55 ppm of 10 V Errors from temperature changes The optimum technical specifications of the 3458A are based on auto calibration ACAL of the instrument within the previous 24 hours and following ambient temperature changes of less than 1 C The 3458A s ACAL capability corrects for measurement errors resulting from the drift of critical components from time and temperature The following example
382. of the message is input when room becomes available in the buffer Query Command The INBUF query command returns the present input buffer mode Refer to Query Commands near the front of this chapter for more information The following program enables the input buffer prior to running all of the autocalibration routines This prevents the bus from being held during the autocal which takes over 11 minutes to complete 10 OUTPUT 722 INBUF ON ENABLE INPUT BUFFER 20 OUTPUT 722 ACAL ALL AUTOCAL TAKES gt 11 MINUTES 30 END ISCALE Integer Scale Query Returns the scale factor for readings output in the SINT or DINT formats Chapter 6 Command Reference 187 ISCALE Syntax ISCALE Remarks Examples The scale factor is always 1 for the ASCH SREAL and DREAL output formats Readings output in the SINT or DINT formats see the ORORMAT command are first compressed by the multimeter so they may be expressed as integers Multiplying the readings by the value returned by ISCALE will restore them to their actual values The scale factor is determined by the configuration of the multimeter when ISCALE is executed This includes the measurement function range and integration time Therefore the multimeter s configuration must be the same when the scale factor is retrieved as it was when the readings were taken You can retrieve the scale factor after the multimeter is configured but before readings are triggered or i
383. of the signal being measured Numeric coupling Query Parameter Equiv Description DC 1 Selects DC coupled input to level detection circuitry AC 2 Selects AC coupled input to level detection circuitry Power on coupling AC Default coupling AC Level triggering can be used for DC voltage direct sampling and sub sampling The LEVEL command also affects the zero crossing threshold and the input signal coupling for frequency and period measurements For DC voltage and direct sampling level triggering can be used as the trigger event TRIG LEVEL command or the sample event NRDGS n LEVEL command For sub sampling level triggering can be used for the sync source event only SSRC LEVEL command Because of hysteresis the actual level triggering point is the specified percentage 4 of the measurement range e Autozero should be disabled when using level triggering AZERO OFF command for DC voltage measurements Autozero doesn t apply to direct or sub sampling e Query Command The LEVEL query command returns two responses separated by a comma The first response is the currently specified percentage The second response is the present coupling mode Refer to Query Commands near the front of this chapter for more information e Related Commands DCV DSAC DSDC LFILTER NRDGS SETACV SYNC SLOPE SSAC SSDC SSRC TRIG 10 OUTPUT 722 TARM HOLD SUSPENDS TRIGGERING 20 OUTPUT 722 PRESET DIG FAST DCV MEA
384. oltage RATIO control control Numeric control Query Parameter Equiv Description OFF 0 Disables ratio measurements ON 1 Enables ratio measurements using the present measurement function DCV ACV or ACDCV Power on control OFF Default control ON The Q Sense LO and the Input LO terminals must have a common reference and cannot have a voltage difference gt 0 25V The signal voltage can be measured using the DCV ACV or ACDCV measurement function For ACV or ACDCYV any of the three measurement methods ANA RNDM or SYNC may be used The multimeter always uses DCV for the reference voltage measurement The measurable reference voltage range is 12VDC autorange only To specify ratio measurements you first select the measurement function and the measurement method for ACV or ACDCV and then enable ratio measurements with the RATIO command see example below Query Command The RATIO query command returns the present ratio mode Refer to Query Commands near the front of this chapter for more information e Related Commands ACDCV ACV DCV SETACV 10 OUTPUT 722 PRESET NORM SUSPEND READINGS NRDGS 1 20 OUTPUT 722 ACV SELECT AC VOLTAGE MEASUREMENTS 30 OUTPUT 722 SETACV SYNC SYNCHRONOUS ACV MEASUREMENTS 40 OUTPUT 722 RATIO ON ENABLE RATIO MEASUREMENTS 50 OUTPUT 722 TRIG SGL TRIGGER MEASUREMENT 224 Chapter 6 Command Reference RES 60 ENTER 722 A ENTER RATIO 70 PRINT A PRINT RATIO
385. ommonly used when the resistance of the test leads is much less than the value being measured If the lead resistance is large compared to the resistance to be measured readings will be inaccurate For example suppose you are measuring a 1Q resistor located 10 feet away If you use 24 gauge copper wire to make the connections the 20 feet of leads contribute about 0 5 ohms to the measurement This makes the total measurement 1 5 ohms an error of 50 Some other factors that may cause high lead resistance are loose or dirty connections kinked or damaged wires or a very hot environment You can enhance the accuracy of 2 wire ohms measurements with the NULL math operation refer to NULL in Chapter 4 for more information Figure 13 shows the front connections for 2 wire ohms measurements You specify 2 wire ohms measurements using the OHM command For example to specify 2 wire ohms measurements on the IkQ range send OUTPUT 722 OHM 1E3 a CURRENT FLOW TO UNKNOWN RESISTANCE Ba AM Tarm 1080 oK Man AN FOR GUARDED MEASUREMENTS ONLY Sssecrc F I 3 Figure 13 2 Wire ohms measurement connections 4 Wire Ohms The 4 wire ohms mode eliminates the measurement error caused by test lead resistance In 2 wire ohms the voltage measurement is made across the combined resistance of the test leads and the unknown resistance In 4 wire ohms the voltage is measured across the unknow
386. ompressing Subprograms Subprogram execution can also be resumed by sending the GPIB Group Execute Trigger this does not in itself trigger a reading it merely resumes subprogram operation You can use a subprogram to call another subprogram nested subprograms For example when the following subprogram is called CALL 1 command it takes 10 DC voltage readings and then calls the previously stored subprogram DCCURI 10 OUTPUT 722 SUB 1 20 OUTPUT 722 TRIG HOLD 30 OUTPUT 722 NRDGS 10 AUTO 40 OUTPUT 722 DCV 10 50 OUTPUT 722 TRIG SGL 60 OUTPUT 722 CALL DCCURI 70 OUTPUT 722 SUBEND 80 END A subprogram containing a PAUSE command cannot be called from another subprogram The multimeter allows you to nest up to 10 subprograms that is having subprogram call subprogram 2 which calls 3 which calls 4 which calls subprogram 10 When you entitle a subprogram 0 that subprogram will be executed whenever the multimeter completes its power on sequence or it is reset using the front panel Reset key This is particularly useful to automatically return the multimeter to its previous state following a power failure Whenever a power failure is detected the multimeter stores its present state as state 0 states are discussed later in this chapter The following program stores an autostart program that returns the multimeter to its power down state and also sets the A D converter s reference frequency to the exa
387. on For most operating conditions the power on reference frequency allows for excellent NMR However for maximum NMR you should set the reference frequency to the exact power line frequency If your power line frequency is subject to drift you may have to periodically correct the reference frequency The following command measures the power line frequency and sets the reference frequency to the exact measured value for a 400Hz line frequency the multimeter divides the measured value by 8 and uses that as the reference frequency OUTPUT 722 LFREQ LINE You can also use the LFREQ command to directly specify the reference frequency This is particularly useful when the multimeter has a different power line frequency than the device being measured Suppose for example 1 Normal mode rejection NMR is the multimeter s ability to reject noise at the power line frequency from DC or ohms measurements 58 Chapter 3 Configuring for Measurements Setting the Integration Time Specifying Power Line Cycles Note the multimeter has a power line frequency of 60 Hz and the device being measured has a power line frequency of 50 Hz For this application you can achieve NMR by setting the reference frequency to 50 Hz as follows OUTPUT 722 LFREQ 50 Remember that whenever power is cycled or the front panel Reset key is pressed the reference frequency returns to the rounded value of 50 or 60 Hz Integration time i
388. on input greater than the present range can measure by outputting the largest number possible for the particular output format as follows 210 Chapter 6 Command Reference Examples OFORMAT SINT format 32767 or 32768 unscaled DINT format 2 147483647E 9 or 2 147483648E 9 unscaled ASCII SREAL DREAL 1 0E 38 e When reading memory is disabled executing the SSAC or SSDC command sub sampling automatically sets the output format to SINT regardless of the previously specified format You must use the SINT output format when sub sampling and not using reading memory The output format applies only to readings transferred over the GPIB bus Responses to query commands are always output in ASCII format regardless of the specified output format Following the query response the output format returns to the specified type The output format does not affect the memory format specified by the MFORMAT command When using the SINT or DINT output formats the multimeter applies a scale factor to each reading This scale factor is based on the present measurement function range A D setting and enabled math operations Therefore ensure that the multimeter s configuration is the same when retrieving the scale factor ISCALE command as it was when the readings were made e You should not use the SINT or DINT output or memory format for frequency or period measurements when a real time or post process math function is enabled e
389. onnections for this example are shown in Figure 21 10 OUTPUT 722 PRESET NORM DCV NRDGS 1 AUTO TARM AUTO TRIG SYN 20 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 30 OUTPUT 722 TRIG EXT TRIGGER EVENT EXTERNAL 40 OUTPUT 722 TBUFF ON ENABLE TRIGGER BUFFERING 50 OUTPUT 722 EXTOUT ICOMP NEG INPUT COMPLETE EXTOUT LOW GOING TTL 55 CONFIGURE EXTERNAL SCANNER 60 OUTPUT 709 SADV EXTIN ADVANCE SCANNER ON MULTIMETER S EXTOUT SIGNAL 70 OUTPUT 709 CHCLOSED EXT OUTPUT LOW GOING PULSE AFTER EACH CLOSURE 80 OUTPUT 709 SCAN 201 206 SCAN CHANNELS 01 06 ON SCANNER IN SLOT 200 85 AND ADVANCE TO CHANNEL 01 STARTING THE SCAN 90 END Aperture Waveform When specified the aperture waveform event APER event outputs a waveform indicating when the A D converter is measuring the input signal In addition to showing when a reading is being measured the aperture waveform also shows any autozero and autorange measurements being made This waveform can be used to synchronize external switching equipment to the multimeter For example to ensure an electrically quiet environment for high accuracy measurements it may be necessary to suspend the operation of external switching equipment while the A D converter is integrating each reading This can be done by enabling the APER event and by programming the external switching to occur only when the aperture waveform indicates that the A D converter is not integrating the input
390. ons can be enabled at the same time The operations are performed on each reading in the order listed in the command For example to enable the NULL and SCALE operations send OUTPUT 722 MATH NULL SCALE ENABLES REAL TIME NULL amp SCALE or OUTPUT 722 MMATH NULL SCALE ENABLES POST PROCESS NULL amp SCALE To disable all enabled math operations send OUTPUT 722 MATH OFF DISABLES ALL REAL TIME MATH OPERATIONS or OUTPUT 722 MMATH OFF DISABLES ALL POST PROCESS MATH OPERATIONS Later you can re enable the operation s that were disabled by the MATH OFF or MMATH OFF command To re enable a single math operation if two operations were previously enabled this will enable only the first of Chapter 4 Making Measurements Math Registers NULL those two operations send OUTPUT 722 MATH CONT RE ENABLES ONE REAL TIME MATH OPERATION or OUTPUT 722 MMATH CONT RE ENABLES ONE POST PROCESS MATH OPERATION To re enable two previously enabled math operations send OUTPUT 722 MATH CONT CONT RE ENABLES TWO REAL TIME MATH OPERATIONS or OUTPUT 722 MMATH CONT CONT RE ENABLES TWO POST PROCESS MATH OPERATIONS Table 23 shows the registers used by the real time or post process math operations Table 23 Math Registers Register Name Register Contents DEGREE Time constant for FILTER and RMS LOWER Smallest reading in STATS MAX Upper limit for PFAIL operation MEAN Average of rea
391. or DC current measurements For 2 wire ohms measurements with offset compensation enabled the zero measurement and offset measurement are done simultaneously Autozero should be on for 4 wire ohms measurements If you must disable autozero be sure to make all measurement connections before disabling autozero and ensure that the lead resistance will not change If you disable autozero before making the 4 wire connections or if you have a varying lead resistance with autozero disabled such as when scanning you will get inaccurate 4 wire ohms measurements Query Command The AZERO query command returns the present autozero mode Refer to Query Commands near the front of this chapter for more information Related Commands DCI DCV FUNC OHM OHMF Example ovureur 722 AZERO OFF DISABLES AUTOZERO Chapter 6 Command Reference 163 BEEP BEEP CAL CALL 164 Syntax control Remarks Example Syntax name Controls the multimeter s beeper When enabled the beeper emits a 1 kHz beep if an error occurs BEEP control The control parameter choices are Numeric control Query Parameter Equiv Description OFF 0 Disables the beeper ON 1 Enables the beeper ONCE 2 Beeps once then returns to previous mode either OFF or ON Power on control last programmed value Default control ONCE The multimeter stores the control parameter in continuous memory the parameter is not lost when power
392. or the trigger parameter is SGL Press Press Notice that the multimeter takes one reading and then stops after the single trigger the trigger event becomes HOLD regardless of the previously specified trigger event You can also enter 1 to select the default value Press Enter Enter jee The multimeter again takes a single reading and then stops Some commands use numeric parameters A numeric parameter is the actual value used by the multimeter We will use the NPLC configuration key to Exponential Parameters Multiple Parameters demonstrate numeric parameters Press NPLC This display shows Notice that if you press the up or down arrow key no parameter choice is displayed This means there is no menu and you must enter a number For example press 2 fea You have now selected power line cycle of integration time for the A D converter Integration time is the actual time that the A D converter measures the input signal Integration time is discussed in detail in Chapter 3 You can also enter numeric parameters using exponential notation For example press Enter ti ENE oe 9 ea Ga Ga E You have now selected 0 1 power line cycles of integration time At this point you should reset the multimeter to return the number of power line cycles to 10 by pressing Reset ae Many commands have more than one parameter Multiple parameters are separated by
393. ory first see the SCRATCH command in chapter 6 If you refer to a real number within a command that expects an integer the 3458A converts the real number to an integer Likewise if you refer to an integer number within a command that expects a real number the 3458A converts the integer number to a real number Therefore you can minimize system overhead time by allocating variables according to their use For example OUTPUT 722 REAL TIME INT LET TIME INT 2 25 TIMER TIME INT The 3458A automatically converts between real and integer values whenever necessary When real numbers are converted to integer representations information may be lost Two potential problem areas exist in this conversion rounding errors and range errors e When a real number is converted to an integer the real value is rounded to the closest integer value All information to the right of the decimal point is lost Range errors exist when converting real values to integer values While 308 30 S real values range from approximately 10 to 107 the integer range is only from 32768 to 32767 approximately 104 to 10 Therefore not all real numbers can be rounded to an equivalent integer value This problem can generate Integer Overflow error Simple variable and array names may contain up to 10 characters The first character must be a letter A Z but the remaining nine characters can be letters numbers 0 9 the underscore char
394. ou can then execute the string by pressing the Enter key The Def Key allows you to assign a command string to any of the user defined keys For example to assign the commands NRDGS 10 AUTO TRIG SGL the semicolon links multiple commands to the user defined key f0 press Def Key je Ld Q The display shows N Rgds Trig a To store the string this does not execute the string it merely assigns it to the user defined key press To access and execute the string assigned to key f0 press Bo a The multimeter will take 10 readings and then stop E e e ca R se Ca As a special keyboard feature you can access the string assigned to a key without pressing the shift key except when you are in the process of entering a command For example you can access and execute the string assigned to key f0 by pressing ei You can also assign commands from the command menu to user defined keys You cannot assign a command using an immediate execute key DCV ACV etc Instead you must access that command from the menu Key definitions stored from the front panel can be edited from the front panel You cannot edit a key definition that was downloaded from the controller Editing is done by pressing the user defined key and while the string is displayed editing the string as described under Display Editing earlier in Installing the Keyboard Overlay this section
395. ous event ensures that the controller is ready to accept readings and will not slow the reading rate Refer to 84 Chapter 4 Making Measurements 10 20 30 40 50 60 70 10 20 30 40 50 60 70 80 OPTION BASE 1 DIM Rdgs 15 High Speed Mode later in this chapter for more information In the following program the PRESET NORM command sets the trigger event to synchronous Line 40 specifies 15 readings per synchronous trigger event Line 50 requests data from the multimeter This satisfies the synchronous trigger event and initiates the readings Notice that line 50 requests data from the multimeter 15 times When multiple readings are specified and SYN is used as the trigger or trigger arm event the multimeter does not recognize the multiple data requests as individual SYN events That is in this program the SYN trigger event occurs once not 15 times COMPUTER ARRAY NUMBERING STARTS AT 1 DIMENSION ARRAY FOR 15 READINGS OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN DCV AUTORANGE MEM OFF OUTPUT 722 NRDGS 15 AUTO 15 READINGS TRIGGER AUTO SAMPLE EVENT ENTER 722 Rdgs GENERATE SYN EVENT ENTER READINGS PRINT Rdgs DISPLAY READINGS END OPTION BASE 1 DIM Rdgs 15 The following program uses the synchronous event as the sample event Line 60 requests data from the multimeter 15 times When SYN is used as the sample event each request for data is recognized as a SYN event That is in this program the SYN ev
396. ove The 3458A is linear to 16 bits at 100 000 readings s Magnitude dB Frequency Hz The 3458A offers two input paths The differences are that the direct ADC path DCV offers up to 160 kHz bandwidth up to a sampling rate of 100 000 samples per second the track and hold path offers 12 MHz bandwidth at a sampling rate of 50 000 readings per second Both paths exhibit single pole roll off both are nominally three dB down half power at the bandwidth point Hence two errors can creep into your measurements aliasing and amplitude roll off In the track and hold path aliasing can be eliminated by increasing the effective sampling rate up to 100 MSamples s and the track and hold circuit can be characterized for amplitude roll off over the band of interest to compensate for the roll off In the case of the DCV path the only real solution to aliasing is to supply a low pass analog filter See Figure 63 Figure 63 Amplitude 0 roll off of the 3458A Multimeter for its two different measurement paths Magnitude dB 1 o Frequency Hz Finally the accuracy of the measurement itself although not often discussed with digitizers is related to the reference accuracy of the 3458A For static and dynamic measurements the absolute accuracy actually exceeds the dmm s resolution And in terms of long term drift the absolute error is less than 7 ppm per year The timebase a precision temperature comp
397. page plots digitized data to the controller s CRT this particular program uses sub sampling and the subroutine Plot_it does the actual plotting This program is helpful when developing digitizing programs especially when sub sampling since it allows you to see the data being captured Since this program simply draws vectors between the samples linear interpolation it works well when the sampling rate is greater than 10 times the frequency of the signal being measured If the sampling rate is less than 10 times the frequency of the input signal this program will plot an incorrect representation of the input signal Figure 34 shows a typical plot produced by this program Note The 3458 Option 005 Waveform Analysis Library is a software package designed to capture and process digitized data It contains routines that initialize the system capture data compare data compute parameters on the data perform Fourier transforms on the data and plot output the data Contact your Keysight Sales Office for more information N il gt H A N ay H gt TIME DIV 0081 Figure 34 Typical plotted waveform 1LOOPTION BASE COMPUTER ARRAY NUMBERING STARTS AT 1 20INTEGER Num_samples Inc 1I J K L DECLARE VARIABLES 30INTEGER Int_samp 1 1000 BUFFER CREATE INTEGER BUFFER 40ALLOCATE REAL Wave _form 1 Num_samples CREATE ARRAY FOR SORTED DATA SOALLOCATE REAL Samp 1 Num_samples CREATE ARRAY FO
398. panel the result goes to the display only When MMATH is executed from remote the result goes to the output buffer only When two post process math operations are enabled operation_a is performed on the reading first Next operation_b is performed on the result of the first operation When a post process math operation is enabled the display s half digit becomes a full digit For example if you are making 4 5 digit AC voltage measurements and then enable the SCALE operation the display is capable of showing 5 full digits Math registers may be written to with the SMATH command Math registers may be read with the RMATH command Query Command The MMATH query command returns two responses separated by a comma which indicate the currently enabled post process math functions Chapter 6 Command Reference MSIZE Example MSIZE e When you use the RMEM command to recall readings it turns off reading memory This means any new readings will not be placed in reading memory and cannot have an enabled memory math operation performed on them When you use the implied read method to recall readings reading memory is not turned off Related Commands MATH MEM RMATH RMEM SMATH The following program performs the post process NULL operation on 20 readings After executing the MMATH NULL command 21 readings are taken and stored in reading memory in FIFO mode Line 80 recalls the first reading taken which is stored in the OFFS
399. perform math operations on readings use the post process math MMATH command Refer to Math Operations later in this chapter for more information MFORMAT DINT Readings come from the A D converter in either SINT or DINT format the format used depends on the specified measurement resolution in the configuration selected by PRESET FAST the A D converter uses DINT The fastest way to transfer readings to reading memory is to have the memory format MFORMAT match the A D converter s format so that no conversion is necessary Refer to Reading Formats earlier in this chapter for information on when to use SINT or DINT OFORMAT DINT Readings come from the A D converter in either SINT or DINT format the format used depends on the specified measurement resolution in the configuration selected by PRESET FAST the A D converter uses DINT The fastest way to transfer readings to the output buffer is to have the output format OFORMAT match the A D converter s format so that no conversion is necessary In addition when the output format matches the reading memory format no conversion is required to recall readings from memory Remember to use the ISCALE command to retrieve the scale factor when using the SINT or DINT output format Refer to Reading Formats earlier in the chapter for information on when to use SINT or DINT Integration Time and Resolution For direct sampled digitizing the format used depends on t
400. pk Earth RMS Noise For RMS noise error Range Multiplier multiply RMS noise result 100 nA x100 from graph by multiplier l uA x10 in chart For peak noise 10 pA to 1A x1 error by 3 error multiply RMS noise Appendix A Specifications Additional error from Tcal or last ACAL 1 C Additional error from Tcal 5 C Specifications are for PRESET NPLC 100 Tcal 1 C Specifications for 90 day 1 year and 2 year are within 24 hours and 1 C of last ACAL Tcal 5 C Add 5 ppm of reading additional error for Keysight factory traceability to US NIST Traceability error is the sum of the 10 V and 10 kQ traceability values Typical accuracy For PRESET DELAY 0 DISP OFF OFORMAT DINT ARANGE OFF Aperture is selected independent of line frequency LFREQ These apertures are for 60 Hz NPLC values where 1 NPLC 1 LFREQ For 50 Hz and NPLC Indicated aperture will increase by 1 2 and reading rates will decrease by 0 833 287 4 I AC Voltage General Information The 3458A supports three techniques for measuring true rms AC voltage each offering unique capabilities The desired measurement technique is selected through the SETACV command The ACV functions will then apply the chosen method for subsequent measurements The following section provides a brief description of the three operation modes along with a summary table helpful in choosing the technique best suited to
401. pling That is if you select AC coupling for the input signal e g DSAC or SSAC the level trigger signal will also be AC coupled regardless of the specified level trigger coupling When the input signal is DC coupled e g DCV DSDC SSDC however you can control the coupling of the level trigger signal with the LEVEL command The level trigger coupling does not affect the input signal coupling The SLOPE command specifies the slope of the signal to use The power on or default values for these commands specify a level percentage of 0 of the present range trigger when the signal crosses zero volts positive slope and AC coupling to the level detection circuitry So in the power on state you LOOUTPUT 20O0UTPUT 300UTPUT 400UTPUT 50END LOOUTPUT 20O0UTPUT 300UTPUT 400UTPUT 45 5V 50END 722 722 22 W229 45 AC COUPLED can select the level triggering shown in Figure 27 merely by specifying the LEVEL trigger event TRIG LEVEL command The following program specifies level triggering to occur when the input signal reaches 5V 50 of the 10V range on a negative slope AC coupled Assuming the input signal has a peak value of 10V and the measurement range is 10V the result is shown in Figure 27 PRESET DIG DCV DIGITIZING 10V RANGE TRIG LEVEL SELECT LEVEL TRIGGER EVENT SLOPE NEG TRIGGER ON NEGATIVE SLOPE OF SIGNAL LEVEL 50 AC LEVEL TRIGGER AT 50 OF 10V RANGE 10V 5V OV 10
402. pm of Reading for Option 002 ppm of Range Range 24 Hour 90 Day gt 1 Year 5 2 Year 5 100 mV 2 543 5 0 3 5 3 9 5 3 14 10 3 1V 1 5 0 3 4 6 3 1 0 3 8 4 0 3 14 10 0 3 10V 0 5 0 05 4 1 2 6 0 05 8 4 0 05 14 10 0 05 100 V 2 5 0 3 6 0 4 5 0 3 10 6 0 3 14 10 0 3 1000 v 2 5 0 1 6 0 4 5 0 1 10 6 0 1 14 10 0 1 Transfer Accuracy Linearity 10 Min Tref 0 5 C Range ppm of Reading ppm of Conditions Range 100 mV 0 5 05 Following 4 hour warm up Full scale to 10 of full scale Measurements on the 1000 V range are within 5 of the 1V 0 3 0 1 initial meausurement value and following measurement 10 V 0 05 0 05 seting Tref is the starting ambient temperature 100 V 0 5 0 1 Measurements are made on a fixed range gt 4 min using 1000 V 1 5 0 05 accepted metrology practices 6 Settling Characteristics For first reading or range change error add 0 0001 of input voltage step additional error Reading settling times are affected by source impedance and cable dielectric absorption characteristics Additional Errors Noise Rejection dB 7 100 4 DC F ACNMR ACECMR ECMR NPLC lt 1 0 90 140 7 i NPLC gt 1 60 150 140 2 NPLC gt 10 60 150 140 a NPLC gt 100 60 160 140 3 NPLC 1000 75 170 140 z 8 2 RMS Noise Range Multiplier For RMS noise ITOT multiply RMS noise 0 1V x20 result from graph by 1V x2 multiplier in chart For 10 V xl peak noise error multiply 100 V x2 RMS noise error by 3 0 01 0 1 1
403. polator settling time To ensure the first sample is accurate insert a 500ns delay using the DELAY 500E 9 command When sub sampling the delay is inserted between the sync Chapter 5 Digitizing 143 Sending Samples to Memory Sending Samples to the Controller 144 source event and the first sample in each burst the default delay for sub sampling is 0 seconds When samples are sent directly to reading memory MEM FIFO command the multimeter automatically re orders the samples producing a composite waveform For example in the following program the sub sampled data is sent to reading memory using the required SINT memory format The multimeter places the samples in memory in the corrected order The samples are then transferred to the controller using the DREAL output format when placing sub sampled data in reading memory first you are not restricted to using the SINT output format 1LOOPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20REAL Samp 1 200 BUFFER CREATE BUFFER ARRAY 30ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 40ASSIGN Samp TO BUFFER Samp ASSIGN BUFFER 50OUTPUT Dvm PRESET FAST TARM SYN TRIG AUTO DINT FORMATS 600UTPUT Dvm MEM FIFO FIRST IN FIRST OUT READING MEMORY 7OOUTPUT Dvm MFORMAT SINT SINT MEMORY FORMAT 8QOUTPUT Dvm OFORMAT DREAL DOUBLE REAL OUTPUT FORMAT Q9OOUTPUT Dvm SSDC 10 SUB SAMPLING 10V RANGE DC COUPLED OQOOUTPUT Dvm SWEEP 5E 6 200 5u
404. ponse of the filter The temperature related math operations convert the measured resistance of a thermistor or RTD into a Fahrenheit or Celsius temperature reading Table 25 describes each of the temperature related math operations The resistance measurement can be made in either 2 wire ohms OHM command or 4 wire ohms OHMF command For the greatest accuracy use the 4 wire ohms mode Conditions that affect the accuracy of a typical resistance measurement also affect the accuracy of temperature measurements see Resistance Measurements and Calibration in Chapter 3 Chapter 4 Making Measurements 125 126 Table 25 Temperature Related Math Operations MATH Operation CTHRM2K Description Result temperature Celsius of a 2kQ thermistor 40653A CTHRM Result temperature Celsius of a 5kQ thermistor 40653B CTHRM10K Result temperature Celsius of a 10kQ thermistor 40653C FTHRM2K Result temperature Fahrenheit of a 2kQ thermistor 40653A FTHRM Resutt temperature Fahrenheit of a 5kQ thermistor 40653B FTHRM10K Result temperature Fahrenheit of a 10kQ thermistor 40653C CRTD85 Result temperature Celsius of 100Q RTD with alpha of 0 00385 40654A or 406548 CRTD92 Result temperature Celsius of 100Q RTD with alpha of 0 003916 FRTD85 Result temperature Fahrenheit of 100Q RTD with alpha of 0 00385 40654A or 40654B FRTD92 Result temperature Fahr
405. power specify another delay value or default the delay parameter DELAY 1 command which returns to the automatic delay The following program uses the DELAY query command to respond with the delay time for the PRESET NORM state 10 OUTPUT 722 PRESET NORM 20 OUTPUT 722 DELAY 30 ENTER 722 AS 40 PRINT A 50 END External Triggering The external EXT event allows the multimeter to be triggered from an 10 20 30 50 60 70 80 external source This event can be used as the trigger arm the trigger event and or the sample event The EXT event occurs on a negative edge transition ofa TTL pulse applied to the multimeter s rear panel Ext Trig connector The minimum pulse width recognized is 250ns The bandwidth of the external trigger circuitry is 5MHz The following program uses the EXT event as the trigger event The sample event is AUTO the number of readings per trigger event is set to 1 Upon the arrival of a negative edge transition on the Ext Trig terminal the multimeter takes a reading which is transferred to the controller A second negative edge transition initiates the second reading which is transferred to the controller This sequence continues until all 20 readings are completed and transferred to the controller OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 DIM Rdgs 20 DIMENSION ARRAY FOR READINGS OUTPUT 722 PRESET NORM TARM AUTO TRIG SYN NRDGS 1 AUTO OUTPUT 722 TRIG EXT TRIGGER EACH READIN
406. pplied This method works well for measuring signals in the frequency range of 10 Hz to 2 MHz and can provide the fastest reading rate of the three methods The random sampling conversion takes numerous samples of the input signal for each reading generated Samples are spaced randomly by an internal time base generator and the signal s true RMS value is calculated statistically Random sampling does not require a repetitive input signal as does synchronous sampling making it suitable for applications such as wideband noise measurements This method has excellent linearity good accuracy and is particularly suited to low level lt 1 10 of full scale measurements The measurement bandwidth for random sampling is 20 Hz to 10 MHz When power is applied the multimeter selects the analog RMS conversion In the power on state you can make measurements using the analog RMS conversion simply by selecting AC or AC DC voltage measurements as follows OUTPUT 722 ACV SELECTS AC COUPLED AC VOLTAGE MEASUREMENTS or OUTPUT 722 ACDCV SELECTS DC COUPLED AC VOLTAGE MEASUREMENTS The SETACV command allows you to specify the AC voltage measurement method For example to specify the random sampling conversion send OUTPUT 722 SETACV RNDM To select the synchronous sampling conversion send OUTPUT 722 SETACV SYNC To return to the analog RMS conversion send OUTPUT 722 SETACV ANA The specified AC voltage
407. pported by the 3458A s internal BASIC language operating system With this feature many of your special requirements can be easily satisfied by writing and downloading a simple BASIC subprogram to customize the multimeter s behavior The following is a list of possible situations where you might find the internal BASIC language to be useful e Customize the front panel display readouts for enhanced user friendliness Add new measuring functions math operations or specialized transducer linearizations e Configure the multimeter to run extra high throughput system measurements Perform GPIB intensive data reduction internal to the multimeter Download your Motorola 68000 binary programs for FFTs etc Keysight custom binary programs to satisfy your special needs Simply create a new subprogram in the 3458A s program memory space using the multimeter s SUB command You may include any multimeter commands as discussed in chapter 6 You may also include any of the new BASIC language commands described in this supplement to build simple BASIC programs It s that easy and yes these commands will work with all revisions of the 3458A s instrument firmware except as noted Subprograms can be called from the GPIB bus assigned to a front panel user defined key FO through F9 for a single key press operation or called from within another subprogram The 3458A s BASIC language does not support the following concepts String va
408. pter 6 Command Reference AZERO control The control parameter choices are Remarks Numeric Control Query Parameter Equiv Description OFF 0 Zero measurement is updated once then only after a function range aperture NPLC or resolution change ON 1 Zero measurement is updated after every measurement ONCE 2 Zero measurement is updated once then only after a function range aperture NPLC or resolution change Power on control ON Default control ON When autozero is ON the multimeter makes a zero measurement measurement with the input disabled following every reading and algebraically subtracts the zero measurement from the reading This approximately doubles the time required per reading Notice that the control parameters OFF and ONCE have the same effect When autozero is OFF or ONCE the multimeter makes one zero measurement and algebraically subtracts this from subsequent readings After you execute AZERO OFF or AZERO ONCE the multimeter takes the autozero measurement when the first trigger arm event occurs for all events except TARM EXT which causes an autozero measurement when the TARM EXT command is executed The autozero measurement will be updated whenever the measurement function range or integration time is changed this update will be made when the trigger arm event occurs or TARM EXT is executed The display annunciator AZERO OFF illuminates when autozero is disabled Autozero cannot be disabled f
409. pter 6 Command Reference 205 NRDGS NRDGS Examples Syntax interaction occurs between NPLC or APER when you specify resolution as follows If you send the NPLC or APER command before specifying resolution the multimeter satisfies the command that specifies greater resolution more integration time If you send the NPLC or APER command after specifying resolution the multimeter uses the integration time specified by the NPLC or APER command and any previously specified resolution is ignored The more common approach is the first of the two shown above i e the NPLC command is executed first to establish normal mode noise rejection NMR then resolution is specified with a function or RANGE command This ensures you will have NMR and at least the required resolution Query Command The NPLC query command returns the integration time in units of PLCs used by the A D converter Since the integration time can be set by the APER NPLC or RES command or the resolution parameter of a function command or the RANGE command it is possible for the NPLC command to return a different number of PLCs than was last specified by the NPLC command e Related Commands APER FUNC LFREQ RES In the following program line 10 sets the number of PLCs to minimum and allows _resolution in line 20 to control the resolution The resolution specified by line 20 is 100uV 10 OUTPUT 722 NPLC 0 SETS PLCS TO MINIMUM 20 OUTPUT 72
410. r and how to determine the reading rate For DC voltage DC current 2 or 4 wire ohms and direct or sub sampled measurements the multimeter enters the high speed mode when readings are initiated the integration time is less than 10 PLCs and the following commands have been executed ARANGE OFF DISP OFF MATH OFF MFORMAT SINT or DINT OFORMAT SINT or DINT only required when reading memory is not enabled only required when reading memory is enabled While readings are being taken in the high speed mode the multimeter becomes completely dedicated to the measurement process This means that it will not process any commands until the specified readings are completed When readings are being sent directly to the output buffer in the high speed mode the multimeter waits until each reading is removed from the output buffer before placing the next reading in the output buffer This ensures that readings will not be lost because of bus controller speed limitations When not in the high speed mode the multimeter will write over any reading in 1 Refer to chapter 5 for more information on direct and sub sampled measurements 102 Chapter 4 Making Measurements Note Configuring for Fast Readings Note PRESET FAST Command the output buffer when a new reading is available If reading memory is enabled in the FIFO mode and reading memory becomes full in the high speed mode the trigger arm event becomes HOLD which stops
411. r OHM or OHMF max _input Selects Full Parameter Range Scale l or AUTO Autorange 0 to 12 10Q 120 gt 12 to 120 100Q 120kQ gt 120 to 1 2E3 1kQ 1 2kQ gt 1 2E3 to 1 2E4 10kQ 12kQ gt 1 2E4 1 2E5 100kQ 120kQ gt 1 2E5 to 1 2E6 IMQ 1 20MQ gt 1 2E6 to 1 2E7 10MQ 12MQ gt 1 2E7 1 2E8 100MQ 120MQ gt 1 2E8 1 2E9 1GQ 1 2GQ Power on max _input AUTO Default max _input AUTO _resolution For DCI max _input Selects Full Parameter Range Scale l or AUTO Autorange 0 to 12E 6 pA 12uA gt 12E 6 to 1 2E 6 1pA 1 2pHA gt 1 2E 6 to 12E 6 10A 124A gt 12E 6 to 120E 6 1004A 120uA gt 120E 6 to 1 2E 3 ImA 1 2mA gt 1 2E 3 to 12E 3 10mA 12mA gt 12E 3 to 120E 3 100mA 120mA gt 120E 3 to 1 2 1A 1 05A For ACI or ACDCI max _input Selects Full Parameter Range Scale 1 or AUTO Autorange 0 to 120E 6 1004A 120uA gt 120E 6 to 1 2E 3 ImA 1 2mA gt 1 2E 3 to 12E 3 10mA 12mA gt 12E 3 to 120E 3 100mA 120mA gt 120E 3 to 1 2 1A 1 05A For DSAC or DSDC Full Scale max _input Selects SINT DINT Parameter Range format format 0 to 012 10mV 12mV 50mV gt 012 to 120 100mV 120mV 500mV gt 120 to 1 2 1V 1 2V 5 0V gt 1 2 to 12 10V 12V 50V gt 12 to 120 100V 120V 500V gt 120 to 1E3 1000V 1050V 1050V For SSAC or SSDC max _input Selects Full Parameter Range Scale 0 to 012 10mV 12mV gt 012 to 120 100mV 120mV gt 120 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V
412. r before It also means that one can take advantage of the increased accuracy and resolution and make measurements at 1 PLC with the 3458A that previously would have taken 10 PLC For the measurement that requires only high speed or a trade off of resolution and accuracy without line noise as an issue the 3458A provides a range of alternatives from 4 1 2 digits at 500 nanoseconds aperture to 8 1 2 digits at 1 seconds aperture and anywhere in between in 100 nanosecond steps Figure 44 shows the aperture versus measurement speed noise resolution and accuracy From the graph in Figure 44 one can see the influence of the actual aperture or integration period on reading rate hidden is the influence of the HPML commands on throughput and some of the basic operating methods of the 3458A HPML is an application oriented command set The basic philosophy behind this command set is that you don t need know what the 3458A is doing to make the measurement but need only to understand the measurement you want to make To optimize throughput for any complex application however requires more understanding of the operation of the 3458A than simply to make a measurement Many of the trade offs you will make involve trading speed for accuracy and convenience The HPML commands that most affect the throughput speed from a measurement viewpoint are FUNC lt DCV DCI OHM FOHM gt lt range gt lt resolution in gt NPLC APER lt integration period s gt R
413. r example to Su bprog rams delete the subprogram named DCCURI send OUTPUT 722 DELSUB DCCURI You can also delete all stored subprograms and all stored states using the SCRATCH command Using State Memory You can store the multimeter s present configuration measurement function range resolution integration time etc as a particular state in state memory Subprograms readings and the contents of some math registers see the SSTATE command in Chapter 6 for details are not included as part of a stored state In the event of a power loss the multimeter stores its present configuration in state 0 if you store a state in location 0 it will be overwritten with the present configuration when power is removed The multimeter has 14k bytes of memory which are used for both states and subprograms Each state occupies about 300 bytes If no subprograms are in memory the multimeter can store a maximum of 46 states When subprogram state memory becomes full the multimeter generates the Memory Error bit 7 in the error register Sto ring States The SSTATE command stores the multimeter s present state with an identifying name A state name may contain up to 10 characters The name can be all alpha characters or a combination of alpha and numeric characters the characters and _ can also be included in the name You can also use an integer in the range of 0 to 127 as the name this is primarily for front panel operation When using a
414. r failure the multimeter can be configured to its previous state by executing RSTATE 0 e All states are stored in continuous memory not lost when power is removed e Subprograms the contents of reading memory user defined keys and the front panel MENU mode are not included as part of a stored state The contents of the following math registers are stored when you store a state all other math registers are set to 0 DEGREE REF LOWER RES OFFSET SCALE PERC UPPER The multimeter has 14k bytes of state memory Each state occupies approximately 300 bytes allowing a maximum of 46 stored states State 0 is reserved for storing the multimeter s state when power is removed State 0 may be also be used for storing other states but the stored state will be overwritten with the present state when power is removed From the front panel you can review the names of all stored states by pressing the Recall State key and using the up and down arrow keys When you have 244 Chapter 6 Command Reference Example STB found the desired state press the Enter key to recall that state e Related Commands MSIZE PURGE RSTATE SCRATCH OUTPUT 722 SSTATE B2 STORES PRESENT STATE WITH NAME B2 STB Syntax Status Register Conditions Remarks Example Status Byte Query The status register contains seven bits that monitor various multimeter conditions When a condition occurs the corresponding bit is set in the status regis
415. r fuse 21 Requirements grounding 17 line power 17 RES 224 RESET 225 Reset key 32 Resetting the multimeter 32 Resistance 56 fixed input 62 Resolution integration time and 104 specifying 60 68 when to specify 61 69 restricted rights statement 2 REV 227 RMATH 227 RMEM 228 RMS conversion analog 64 RQS 229 RSTATE 230 Running autocal 49 S safety symbols 3 Sample event 82 Samples to memory 144 to the controller 144 Sampling rate 131 remarks synchronous 63 Sampling conversion random 64 synchronous 63 SCAL 231 SCALE 119 SCRATCH 231 Scroll keys menu 36 SECURE 231 Selecting input terminals 50 parameter 33 Self test 30 47 power on 25 Sending readings across the bus 98 remote command 43 samples to memory 144 samples to the controller 144 Serial number 22 Series 200 300 computers 20 Service repair 22 request 114 SETACV 232 Setting Integration time 59 67 line voltage switches 18 Setup triggering 105 SHIFT annunciator 27 Shipping instructions 22 Single integer 92 readings 83 Single real 93 SINT example 99 output format 99 SLOPE 233 SMATH 234 SMPL annunciator 27 Specify 61 Specifying AC voltage method 64 bandwidth 66 integration time directly 60 measurement function 53 power line cycles 59 range 54 ratio measurements 71 370 INDEX resolution 60 68 Specifying Resolution when to 69 SREAL example 93 output forma
416. r sub sampled measurements To select a range you specify max _input as the input signal s expected peak amplitude The multimeter then selects the correct range The following table shows the max _input parameters and the ranges they select max _input Selects Full Parameter Range Scale 0 to 012 10mV 12mv gt 012 to 120 100mV 120mV gt 120 to 1 2 1V 1 2V gt 1 2 to 12 10V 12V gt 12 to 120 100V 120V gt 120 to 1E3 1000V 1050V Power on max _ input not applicable Default max _input 10V resolution Is ignored by the multimeter when used with the SSAC or SSDC command This parameter is allowed in the command syntax to be consistent with the other function commands FUNC ACI DCV etc e Autozero and autorange do not function for sub sampled measurements Executing the SSAC or SSDC command suspends autozero and autorange operation e As with direct sampling you can specify a level triggering voltage up to 500 ofthe range The required SINT format however cannot handle samples greater then 120 of range e Ifreading memory is disabled when you execute the SSAC or SSDC command the multimeter automatically sets the output format to SINT the memory format Chapter 6 Command Reference 237 SSAC SSDC 238 is not changed Later where you change to another measurement function the output format returns to that previously specified You must use the SINT output format when sub sampling and outputting sample
417. r this example on the first period of the input signal the multimeter takes a burst of 5 samples On the second period the multimeter delays the trigger point by 5us and takes another burst of 5 samples On each of the remaining two periods the multimeter delays the trigger point by another 5ps and takes a burst of 5 samples As shown in Figure 32 when all the samples are arranged in the proper sequence the result is one period of the input signal consisting of 20 samples spaced at 5us intervals In this example then the effective sampling rate is 200 000 samples per second The Sync Source Event PERIOD 1 PERIOD 2 PERIOD 3 PERIOD 4 12 16 D Figure 31 Sub sampling example 14 19 Figure 32 Composite waveform In the preceding sub sampling example it was assumed that the multimeter could somehow synchronize itself to the periods of the input waveform This is the function of the sync source event You can use either the EXT event or the LEVEL event as the sync source event The EXT sync source event specified by the SSRC EXT command occurs on the negative edge transition on the multimeter s Ext Trig connector This requires an external pulse that is synchronous with the input signal Figure 33 shows a typical input signal and the required synchronizing signal Notice in Figure 33 that the synchronizing signal does not necessarily have to occur once for every period of the input signal It does however have to be synchro
418. rameters are used to determine the amount of time needed for autoranging For these measurements it is very important that the specified bandwidth especially low_frequency corresponds to the frequency content of the signal being measured If you are unsure of the frequency content of the input signal default the 158 Chapter 6 Command Reference Example ACDCI ACDCV ACI ACV ACBAND parameters Query Command The ACBAND query command returns two numbers separated by a comma The first number is the currently specified low_frequency the second number is the high frequency Refer to Query Commands near the front of this chapter for more information e Related Commands ACDCI ACDCV ACI ACV FREQ FUNC PER SETACV OUTPUT 722 ACBAND 500 1000 SPECIFIES THAT THE INPUT SIGNAL IS BETWEEN 500 1000 Hz ACDCI ACDCV ACI ACV ADDRESS Syntax value Remarks Refer to the FUNC command Sets the multimeter s GPIB address from the front panel only The address is stored in continuous memory and is not lost when power is removed ADDRESS value The value parameter is an integer from 0 to 31 Power on value previously stored address factory setting 22 Default value none parameter required When you specify address 3 1 it doesn t actually change the multimeter s address but sets the multimeter to the Talk Only mode In this mode the multimeter outputs readings directly to an GPIB printer without
419. ration_b OFF OFF Default operation_a operation_b OFF OFF Chapter 6 Command Reference 201 MMATH 202 Power on register values a11 registers are set to 0 with the following exceptions DEGREE REF 1 20 SCALE 1 RES 50 PERC 1 Remarks Any enabled post process math operations except STAT and PFAIL are performed on each reading as it is removed or copied from reading memory to the display or the GPIB output buffer The readings in memory are not altered by any post process math operation The STAT or PFAIL post process math operations are performed using the readings in memory immediately after executing the MMATH command The STAT and PFAIL operations are not updated for any additional readings placed in memory after executing the MMATH command For the STAT operation results are stored in the SDEV MEAN NSAMP UPPER and LOWER math registers refer to the RMATH command for information on these registers For the PFAIL operation whenever an out of limit reading is detected bit number in the status register is set this sets the GPIB SRQ fine if enabled by the RQS command and the display shows the FAILED LOW or FAILED HIGH message Anenabled post process math operation remains enabled until you set MMATH OFF enable a real time math operation MATH command or execute the MMATH command specifying another math operation except as described in the following remark When MMATH is executed from the front
420. rature Coefficient ean eet Range Full Scale Resolution Input Impedance of Reading of Range C aaa ae ET WRA 10 mV 12 00000 10nV 1 MQ 15 with lt 140pF 0 003 0 006 24 hours and 1 C of Iast 100mV 120 0000 100nV 1 MQ 15 with lt 140pF 0 002 0 ACAL Lo to Guard switch 1V 1 200000 1pV 1 MQ 15 with lt 140pF 0 002 0 onto 10 V 12 00000 10uV 1 MQ 2 with lt 140pF 0 002 0 Maximum DC is limited to 100 V 120 0000 100 pV 1 MQ 2 with lt 140pF 0 002 0 400 V in ACV function 1000V 700 000 Ss 1 mV 1 MQ 2 with lt 140pF 0 002 0 Add 2 ppriof reading additional error for factory traceability of 10V DC to US ACAccuracy 2 NIST 24 Hour to 2 Year Reading Range Range 10Hz to 20 Hzto 40Hzto 100 Hzto 20kHzto 50kHzto 100kHzto 250kHzto 500 kHzto 1 MHz to 20 Hz 40 Hz 100 Hz 20 kHz 50 kHz 100 kHz 250kHz 500kHz 1 MHz 2 MHz 10 mV 0 4 0 32 0 15 0 25 0 06 0 25 0 02 0 25 0 15 0 25 0 7 0 35 4 0 7 100 mV 10 V 0 4 0 02 0 15 0 02 0 06 0 01 0 02 0 01 0 15 0 04 0 6 0 08 2 0 5 3 0 6 542 10 5 100 V 0 4 0 02 0 15 0 02 0 06 0 01 0 03 0 01 0 15 0 04 0 6 0 08 2 0 5 3 0 6 5 2 1000 V 0 42 0 03 0 17 0 03 0 08 0 02 0 06 0 02 0 15 0 04 0 6 0 2 AC DC Accuracy ACDCV Function For ACDCV Accuracy apply the following additionat error to the ACV accuracy of Reading of Range DC lt 10 of AC Voltage DC gt 10 of AC Voltage 3 Additional error beyond Temperature sate Jase Range Accuracy 3 Accuracy Temperature Coefficie
421. re descriptive bit in the auxiliary error register The display s ERR annunciator illuminates whenever an error register bit is set You can access the error registers using ERRSTR both registers ERR error register only or AUXERR auxiliary error register only Related Commands AUXERR ERR ERRSTR OUTPUT 722 TEST RUNS SELF TEST TIMER Syntax Remarks The TIMER command defines the time interval for the TIMER sample event in the NRDGS command When using the TIMER event the time interval is inserted between readings TIMER time time The valid range of the time parameter is 1 maximum sampling rate to 6000 seconds in 100ns increments Power on time 1 second Default time 1 second When using the TIMER event the first reading occurs without the time interval However you can insert a time interval before the first reading using the DELAY command e When using the TIMER event autoranging is suspended typically you should select a fixed range when using the TIMER event If autoranging was enabled when you specified the TIMER sample event autoranging will resume when you specify another sample event The SWEEP command can be used to replace the two commands NRDGSz TIMER and TIMER n for any measurement function The SWEEP and NRDGS are interchangeable the multimeter uses whichever command was executed last in the programming Executing the SWEEP command automatically sets the sample event t
422. red directly to the controller instead of using reading memory However the controller and GPIB must be able to transfer samples at a rate of at least 134k bytes second or the multimeter will generate the TRIGGER TOO FAST error Refer to High Speed Transfer Across the Bus in Chapter 4 for more information 1OOPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20INTEGER Num_samples 1I J K CREATE INTEGER VARIABLES 30Num_samples 200 200 SAMPLES 35ASSIGN Dvm TO 722 DESIGNATE MULTIMETER ADDRESS 40ASSIGN Buffer TO BUFFER 4 Num_samples SETUP CONTROLLER BUFFER FOR 45 SAMPLES 4 BYTES SAMPLE 200 SAMPLES 800 BYTES SOALLOCATE REAL Samp 1 Num_samples CREATE REAL ARRAY FOR SAMPLES 60O0UTPUT Dvm PRESET FAST DINT FORMATS TARM SYN TRIG AUTO 7OOUTPUT Dvm SWEEP 30E 6 200 30us INTERVAL 200 SAMPLES 8O0OUTPUT Dvm DSDC 10 DIRECT SAMPLING 10V RANGE Q9OOUTPUT Dvm LEVEL 250 DC LEVEL TRIGGER AT 250 OF RANGE 25V OQOOUTPUT Dvm TRIG LEVEL LEVEL TRIGGER EVENT LOOUTPUT Dvm MEM FIFO ENABLE READING MEMORY FIFO MODE 20TRANSFER Dvm TO Buffer WAIT TRANSFER SAMPLES TO CONTROLLER 3Q0OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR DINT FORMAT 40ENTER Dvm S ENTER SCALE FACTOR 50FOR I 1 TO Num samples 60 ENTER Buffer USING W W J K ENTER ONE 16 BIT 2 S COMPLEMENT 61 WORD INTO EACH VARIABLE J AND K STATEMENT TERMINATION NOT 65 REQUIRED W ENTER DATA AS 16 BIT 2 S COMPLEMENT INTEGER
423. rent AC current measurements are made strictly through the analog ACV section with the voltage input being supplied by the DCI shunts While there is no real decision to make regarding the mode of ACI measurement you can decide to accept less accuracy and speed up the reading rate by decreasing the integration and settling time As a rule of thumb the AC to DC converter needs at least 10 cycles of the input wave form to give representative rms measurements Hence the frequency of the input has a direct impact on the reading rate Characterization of the 3458A may be necessary to fine tune the measurement throughput for either ACV or ACI to fit your application Appendix D Optimizing Throughout and Reading Rate 329 Frequency and Period The track and hold path is also the route the signal must take for frequency and its reciprocal period The 3458A offers frequency response from 10 Hz to 10 MHz to 7 digits with a maximum gate time of 1 second One can trade speed for accuracy and resolution by selection of shorter gate times of the internal counter Table 32 shows the trade off of resolution for each of the gate times Table 32 Shows resolution trade off for each of the gate times Gate time Resolution Reading Rate 1 second 7 1 2 digit 1 rdgs s 0 1s 6 1 2 10 rdgs s 0 01s 5 1 2 73 rdgs s 0 001 s 4 1 2 215 rdgs s 0 0001 s 3 1 2 270 rdgs s After one has optimized each individual measurement in terms of the mi
424. reur 722 opt QUERY INSTALLED OPTIONS 20 ENTER 722 AS ENTER RESPONSE 30 PRINT AS PRINT RESPONSE 40 END 214 Chapter 6 Command Reference PAUSE Syntax Remarks Example PAUSE Suspends subprogram execution The subprogram can be resumed using the CONT command or by executing the GPIB Group Execute Trigger command PAUSE The PAUSE command is allowed only within a subprogram e Only one subprogram will be preserved in a suspended state If a subprogram is paused and another is run which also becomes paused the first will be terminated and the second will remain suspended e With the input buffer off INBUF OFF command the GPIB bus is normally held by the multimeter until a called subprogram is completely executed If a PAUSE command is encountered in a subprogram the GPIB bus is released immediately Nested PAUSE commands are not allowed that is when a subprogram is called from another subprogram the called subprogram cannot contain a PAUSE command Query Command The PAUSE query command returns a response indicating whether a subprogram is currently paused The possible responses are YES numeric query equiv 1 indicating a subprogram is paused or NO numeric query equiv 0 Related Commands CALL COMPRESS CONT DELSUB TRIGGER GPIB command SCRATCH SUB SUBEND 10 OUTPUT 722 SUB OHMAC1 STORES SUBPROGRAM NAMED OHMAC1 20 OUTPUT 722 PRESET NORM SUSPENDS TRIGGERING PRE
425. riables and operations Line numbers e GOTO statements GOSUB statements Chapter 7 BASIC Language for the 3458A 261 Local variables all variables are global e Parameter passing e Any other BASIC commands not listed in this supplement BASIC Language Commands Variables and Arrays Note RESTRICTIONS ON USING 262 VARIABLES IN SUBPROGRAMS Math Operations This section gives you an overview of the BASIC language commands that are supported by the 3458A s internal BASIC language operating system Refer to the later sections in this chapter for more detailed information and examples on these commands All array indexes are 0 to size option base 0 LET user_variable expression REAL variable l variable_2 Declares a type real user variable Also accepts REAL variable _l size for declaring a real array REAL is a 64 bit value INTEGER variable l variable 2 Declares a type integer user variable Also accepts INTEGER variable_1 size for declaring an integer array INTEGER is a 16 bit value DIM array_name size Dimensions an array FILL array_name list Fills the named array with data from the following number list Filled arrays are stored in volatile memory space ALL subprograms that refer to a given variable must define it The definition for a given variable must match all other definitions for the same variable name If the definition for a user variable varies betw
426. ric alpha or a combination of alpha and numeric Refer to the QFORMAT command in Chapter 6 for more information The shifted Clear key the Back Space key and the Display Window keys left and right arrow keys allow you to control the display Whenever you want to clear information such as a query response from the display press Chapter 2 Getting Started 37 Display Editing Viewing Long Displays Note 38 Chapter 2 Getting Started Clear Back Space The Back Space key allows you to edit parts of a command string while entering the string or when the string is recalled discussed later For alpha parameters or command headers pressing the Back Space key once erases the entire parameter or header For commas spaces and numeric parameters only one character is erased each time you press Back Space For example press mr J J fe Je The display shows By pressing the Back Space key once the entire second parameter LINE is erased The display shows Now by pressing Back Space once the comma is erased Pressing Back Space two more times erases both numeric characters 10 At this point you can reenter the first parameter using the numeric keypad and the second parameter using the Menu Scroll keys Press the Enter key to execute the edited command When entering commands containing more than 16 characters the previously entered characters are scrolled off the left side of the display to make
427. rmation Related Commands MCOUNT MFORMAT MSIZE RMEM OUTPUT 722 MEM FIFO ENABLES READING MEMORY FIFO MODE The MENU command selects the SHORT or FULL list of commands in the front panel s alphabetic command menu Chapter 6 Command Reference 197 MFORMAT MFORMAT Syntax Remarks Example Syntax MENU mode mode The mode parameter choices are Numeric mode Query Parameter Equiv Description SHORT 0 Selects the short command menu FULL 1 Selects the full command menu Power on mode mode selected when power was removed Default mode FULL e To access the alphabetic command menu press any of the shifted MENU keys labeled C E L N R S and T You can then locate a particular command using the up and down arrow keys The mode parameter is stored in continuous memory not lost when power is removed The FULL menu contains all commands except query commands that can be made by accessing a command and appending a question mark e g BEEP BEEP The SHORT menu eliminates the GPIB bus related commands and any commands that have dedicated front panel keys e g RSTATE command Recall State key Query Command The MENU query command returns a response indicating the present menu mode Refer to Query Commands near the front of this chapter for more information Related Commands DEFKEY LOCK OUTPUT 722 MENU SHORT SELECTS SHORT MENU Memory Format Clears reading memory an
428. rmistor Temperature Probe 5k Q E2308A 10k Q Thermistor 34308A 16 Chapter 1 Installation and Maintenance Installing the Multimeter REAR INPUT TERMINALS This section discusses the multimeter s grounding and power requirements and contains instructions for installing the multimeter Refer to Appendix C for instructions on how to install the switch lockout caps Figure 1 shows the multimeter s rear panel Many of the rear panel connectors and switches are referenced in this section INSTALLED OPTIONS IF CHECKED EXT OUT SIGNAL OUTPUT GPIB CONNECTOR CHASSIS GROUND LUG SERIAL NUMBER Grounding Requirements WARNING Line Power Requirements Caution LINE POWER LINE VOLTAGE LINE Power FUSE HOLDER SWITCHES CONNECTOR EXTERNAL TRIGGER INPUT Figure 1 Rear panel The multimeter comes witha three conductor AC power cable see Figure 3 The power cable must be connected to an approved three contact electrical outlet that has its ground conductor connected to an electrical ground safety ground The multimeter s power jack and the supplied power cable meet International Electrotechnical Commission IEC safety standards For protection from electrical shock the power cord ground must not be defeated You can operate the multimeter from a single phase power source delivering 100 VAC 120 VAC 220 VAC or 240 VAC all values RMS at 48 to 440 Hz The power line voltage can vary by
429. roge a toebi augers 193 Parameters iesenii ia 152 MCOUNT gece cecanccvtiea tateesacacenns sev eian e 196 Query Commands ce eccecceeseeeteeeeeeeeeeteeesees 153 MEM Sa Abert teats A ends deena tauehecia 196 Commands by Functional Group csceeeees 155 MENU oles ces cesstantods herdleetutdsthoutedelvateoest aS 197 Commands vs Measurement Functions 156 MFORMAT ka raaa Aaa s 198 ACAD peh eaa teaa ee ho eiaa tsoetan 157 MMATH ooreis ianmerhnterne 200 ACBAND nnan a E an aois 158 MSIZE sarat a a a ERTS 203 ACDCI ACDCV ACI ACV asssssssssssssesese 159 NPI Gar a et n a a aa E aT 204 ADDRESS oeo r ra e E AAR 159 NPE G serie cous E E E a 204 APER EE dante aati eee tsatictavateeetacets 160 NRDSGS ar aaea a a a A E 206 ARANGE ne s eana ee 160 OCOMP reise cccsstivecitcescesnaesvaceieve seein EEEa 209 AUXERR ethionine entire tack lenin 161 OFORMAYT sei aa a a E eas 210 AZP RO t at reat dere iow ea aat 162 OHM OHMF 1 00 ccececcseeseescescesseeeceeeseenseees 214 BEEP a a a N hetalnded 164 OPT apaa a meres earn ay 214 CAE aert e E A E i 164 PAUSE fc Cascio era E 215 CALL EE S TT 164 PER nesenie eaaa i iea 216 CAL NUM ostaa a an ia 165 PRESET canini n aa e aa aaa aat 217 CALS ER EE E 165 PURGE A A A 219 COMPRES Siusi innin nlarerea eerie stecdh ute 166 OFORMA Tiar aa a Sie abe 219 CONT unene anan e e E satis 167 IR EET A E anessitors 221 CSB mentee a a a aaa 167 RANGE mauna a an E E ERA 221 DEL DCV oa ea en aiteis 168 R
430. rogram OUTPUT Dmm MEM FIFO Sets memory to first in first out OUTPUT Dmm DCV 10 Sets the dmm to dcV function and 10 volts mM O t UTPUT Dmm TARM SGL 1 Initiates the measurement sequence once he TRIG EXT is satisfied and stops after just one trigger event occurs OUTPUT Dmm TARM SGL 2 Repeats the sequence again OUTPUT Dmm TARM SGL 3 And again OUTPUT Dmm ACBAND 1000 Sets the lower frequency range to 1 kHz Appendix D Optimizing Throughout and Reading Rate 660 670 680 690 700 710 720 730 740 750 760 770 780 790 800 810 820 830 840 850 860 870 880 890 900 910 920 930 940 950 Greuk STRUT cone me are a UTBUT Gaur ae eT Sue UTPUT ane ae ae sae ae ere On On Ol Onn Onn OM On On OM Onn On On Onn On O O OUTPUT OUTPUT Transfer readings from dmm to computer Dmm ACV Dmm TAR Dmm TAR Dmm DCV Dmm TAR Dmm TAR Dmm ACV Dmm TAR Dmm TAR Dmm DCV Dmm TAR Dmm TAR Dmm OHM Dmm TAR Dmm OCO Dmm TAR 10 Sets the dmm to 10 volts maximum input in acV SG SG Lo SG SG 10 SG SG 10 SG SG 3E3 Sets the dmm to Q function and 3KQ SG PO SG Dmm SUBEND Dmm USING K CALL 1 Scan STEP Moves to the first setup and triggers the dmm FOR I 1 TO 13 ENTER Dmm A I PRINT USING NEXT I SUBEND Appendix D Optimizing Throughout and
431. roller 144 Viewing Sampled Data cccceceesesseesteeteeeteees 146 Chapter 5 Digitizing 127 128 Chapter 5 Digitizing Chapter 5 Digitizing Introduction Digitizing is the process of converting a continuous analog signal into a series of discrete samples readings Figure 22 shows the result of digitizing a sine wave This chapter discusses the various ways to digitize signals The importance of the sampling rate and how to use level triggering Note Asa supplement to the information in this chapter Product Note 3458A 2 in Appendix D discusses the trigger and timebase errors that affect digitized measurements Input signal Samples e es hd Figure 22 Digitized sine wave Digitizing Methods The multimeter can digitize signals by making DC voltage measurements by direct sampling or by sub sampling Table 26 summarizes the characteristics ofeach digitizing method Figure 23 shows a simplified block diagram of the multimeter s signal path for each digitizing method Figure 24 and shows the front terminal connections for all methods of digitizing Chapter 5 Digitizing 129 INPUT 130 Table 26 Digitizing Methods Digitizing Method Maximum Sampling Bandwidth Repetitive Signal Rate Required DCV 100 k sec DC 150kHz No Direct Sampling 50 k sec DC 12MHz No Sub Sampling 100 M sec2 DC 12MHz Yes 1 Range dependent See the Specifications in Appendix
432. rs Error Description Division by Zero Real Overflow Real Underflow Integer Overflow Square Root of a Negative Number Log of a Non Positive Number Illegal Real Number Trig Argument Out of Range BCD Exponent Too Big HEX Octal or Decimal Argument Error If you are making mathematical comparisons between integer numbers no special precautions are necessary However if you are comparing REAL numbers especially those which are the results of calculations it is possible that you might run into problems due to rounding and other limitations inherent in the system For example consider the use of the IF THEN statement to check for equality in any situation resembling the following example 10 OUTPUT 722 SUB TESTER Chapter 7 BASIC Language for the 3458A Subprograms 20 OUTPUT 722 LET A 25 3765477 30 OUTPUT 722 IF SIN A 2 COS A 2 1 THEN 40 OUTPUT 722 DISP EQUAL 50 OUTPUT 722 ELSE 60 OUTPUT 722 DISP NOT EQUAL 70 OUTPUT 722 ENDIF 80 OUTPUT 722 SUBEND 90 100 OUTPUT 722 CALL TESTER 110 END You may find that the equality test fails due to rounding errors or other errors caused by the inherent limitations of finite machines A repeating decimal or irrational number cannot be represented exactly in any finite machine like the 3458A A good example of equality error occurs when multiplying or dividing numbers A product of two non integer
433. rs After reading a bit the ERRSTR command clears that bit The following program uses the ERRSTR command to read all errors one error at a time After all set bits have been read and cleared or if there were no set bits in either register the ERRSTR command returns 0 VO ERROR 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS WITH 1 20 DIM A 200 DIMENSION STRING VARIABLE 30 OUTPUT 722 ERRSTR READS ERROR MESSAGE 40 ENTER 722 A AS ENTERS NUMERIC INTO A STRING INTO AS 50 PRINT A AS PRINTS RESPONSES 60 IF A gt O THEN GOTO 30 LOOP TO READ EACH ERROR 70 END The ERR and AUXERR commands return the decimal sum of all set bits in the error register and the auxiliary error register respectively Refer to these commands in Chapter 6 for example programs and listings of the possible errors Calibration The multimeter has two forms of calibration external calibration and autocalibration The external calibration involves a procedure using external reference sources Refer to the 3458 Calibration Manual for more information on the external calibration The CALNUM query command returns a number indicating the number of times the multimeter has been externally calibrated By routinely checking this number you can monitor the calibrations performed on the multimeter The following program reads and returns the present calibration number 10 OUTPUT 722 CALNUM 20 ENTER 722 A 30 PRINT
434. ry CALL sub_name Executes the named subprogram and waits for completion before executing other commands PAUSE Pauses the most recent subprogram executed with the CALL command CONT Resumes subprogram execution after a PAUSE command is executed FOR counter initial_value TO final value STEP step_size NEXT counter WHILE expression ENDWHILE IF expression THEN ELSE ENDIF CALLARRAY array name integer list Fetches the internal address of the specified array and begins execution there The array must have been previously loaded with data converted to ASCII using the FILL command The binary data must be Motorola 68000 executable code written using relative addressing Chapter 7 BASIC Language for the 3458A 263 New Multimeter Commands 264 The following commands are not documented in chapter 6 but are included in this supplement for your convenience These commands will work with all revisions of the 3458A s instrument firmware except as noted ENTER uwser_variable Transfers a reading from the multimeter s reading memory to a user variable The multimeter reading is erased after execution Example ENTER Dmm OUTPUT user variable Outputs the present value of a user variable The data is sent to either to the display or GPIB output buffer based on the source from which the subprogram was executed Example OUTPUT Result U_RANGE Up ranges once in the present function D_RANGE Down ranges once in the present fu
435. ry responses sent to the display contain alpha headers and alpha responses whenever possible ALPHA Query responses sent to either GPIB or the display contain an alpha header and an alpha response whenever possible Power on type NORM Default type NORM The numeric query equivalents for alpha parameters are shown under each applicable command in this chapter Some query commands such as DEFKEY will always return alpha characters regardless of the specified QFORMAT Similarly some query commands such as NDIG will always return a numeric response When you execute a query command from the multimeter s front panel the result goes to the display only When you execute a query command from the controller the result goes to the multimeter s output buffer only Query results are returned in ASCII format after which the output format returns to the previously specified type ASCII SINT etc Query Command The QFORMAT query command returns the present query format Refer to Query Commands near the front of this chapter for more information Related Commands All query commands OFORMAT NORM 2 O OUTPUT 722 QFORMAT NORM 0 OUTPUT 722 ARANGE 0 ENTER 722 A 0 PRINT A 0 END Typical response 1 NUM 1 2 3 4 5 O OUTPUT 722 QFORMAT NUM 0 OUTPUT 722 ARANGE 0 ENTER 722 A 0 PRINT A 0 END Typical response 1 Chapter 6 Command Reference RANGE Syntax Syntax ALPHA 10 OUTPUT 722
436. s Centigrade TEMP Monitoring the multimeter s tempernture is helpful to determine when to perform autocalibration e Related Commands ACAL CAL CALSTR 10 OUTPUT 722 TEMP READ TEMPERATURE 20 ENTER 722 A ENTER RESULT 30 PRINT A PRINT RESULT 40 END On previous multimeters the TERM command internally connected or disconnected the multimeter s input terminals The 3458 accepts the TERM command to maintain language compatibility with these multimeters but does not respond since the 3458 s input terminals cannot be controlled from remote TERM source source The source parameter choices are Numeric source Query Parameter Equiv Description OPEN 0 Generates error message FRONT 1 Generates error message if Terminals switch is set to Rear REAR 2 Generates error message if Terminals switch is set to Front Power on source none Default source FRONT e Query Command The TERM query command returns a response indicating which input terminals FRONT or REAR are selected by the front panel Terminals switch 254 Chapter 6 Command Reference TEST TEST Syntax Remarks Example Causes the multimeter to perform a series of internal self tests TEST e Always disconnect any input signals before you run self test If you leave an input signal connected to the multimeter it may cause a self test failure e Ifa hardware error is detected the multimeter sets bit 0 in the error register and a mo
437. s all display elements including the annunciators as shown in Figure 8 By holding down the Reset key the multimeter continuously performs its display test SMPL REM SRQ TALK LSTN AZERO OFF MRNG MATH ERR SHIFT MORE INFO Figure 8 Display Test Pressing the shifted front panel Reset key performs the power on sequence which has the same effect as cycling the multimeter s power This destroys any stored reading and compressed subprograms sets the power on SRQ bit in the status register these functions are discussed later in this manual resets the A D converter reference frequency and performs the power on self test Executing the RESET command from the alphabetic command menu MENU keys returns the mulitmeter to the power on state but does not perform the power on sequence The MENU keys are discussed later in this chapter The configuration keys unshifted MENU keys let you rapidly access the most frequently used multimeter features Table 8 shows each key the corresponding multimeter command and the function of each These functions are discussed in detail in Chapters 3 and 4 Table 8 Configuration Key Functions Key Command Description Ruto ACAL Performs one or all autocal routines It takes over 11 minutes to run all of the autocat routines Never reset the multimeter to abort an autocal Once you start an autocal you must complete it z Q oO NPLC Sets integration time in terms of
438. s 271 Math Hierarchy 0 ccccesceeseeseeeseeeteeesteeseees 272 Math Errors esaeen eana eae a Eaa 272 Making Comparisons Work ceseeeeees 272 Subprograms 00 cecceccecscesseeeeeseceseceeeeeeeseeeeeeaaes 273 Writing and Loading Subprograms 06 274 Subprogram Command Types eccesceesereeeee 275 Definition Deletion Commands 006 275 SUB SUBENDD aiee ienee oieee iison 275 DEESUB i cisacatasistiveeeracstvarsensaniesianes 275 SCRATCH vecciceredsiontocstecvecs tats a asvtaeaietends 276 CAT Sion tit eid wants ema neiwaks 276 BIST eeen tree tern etre crore erence rere 276 COMPRESS siosioina 276 Execution Commands cceeeeeeeeeeeeeeeeeees 277 Subprogram CALL ccccceceeseeseeeeeeteeees 277 Subprogram PAUSE ou eeceesesceeseeeteeeees 277 Knowing When a Subprogram is Paused 277 Aborting a Subprogram eeeeeeeeees 277 Exiting a Subprogram ceeeseeeeeeeeeees 277 Nesting Subprograms cecceseeseeteeees 278 Conditional Statements in Subprograms 278 FOR NEXT Loops ceecceeeccesteceeeeeeeneeeees 278 WHILE Loops 2 0 ceeecceecsecesceeeeecenteeeeneeeeneeeees 279 IF THEN Branching cceeccecseesseeteeeteeees 280 Chapter 7 BASIC Language for the 3458A 259 260 Chapter 7 BASIC Language for the 3458A Chapter 7 BASIC Language for the 3458A Introduction How It Works This chapter describes the BASIC commands su
439. s EFF INTERVAL 200 SAMPLES LOTRANSFER Dvm TO Samp WAIT TRANSFER SAMPLES TO CONTROLLER BUFFER 20FOR I 1 TO 200 30 IF ABS Samp I 1E 38 THEN DETECT OVERLOAD 40 PRINT Overload Occurred PRINT OVERLOAD MESSAGE 50 ELSE IF NO OVERLOAD OCCURRED 60 Samp I DROUND Samp I 5 ROUND TO 5 DIGITS 70 PRINT Samp I PRINT EACH SAMPLE 80 END IF 9ONEXT I 200END Chapter 5 Digitizing When samples are sent directly to the controller an algorithm must be used to re order the samples and produce the composite waveform The SSPARM command returns three parameters for the algorithm The first parameter returned is the number of bursts measured that contained M samples The second parameter returned is the number of bursts measured that contained N samples The third parameter returned is the value of N For example assume you are sub sampling a 10kHz signal and specify 22 samples with an effective _interval of Sus In this example the multimeter takes 2 bursts containing 6 samples each and 2 bursts containing 5 samples each Each burst is delayed 5us from the previous burst The values returned by SSPARM are then 2 2 and 6 When sub sampling the maximum sample rate is 50k samples per second regardless of the specified effective_interval If you specify an effective_interval of gt 20us the multimeter is no longer sub sampling but direct sampling When sending samples directly to the controller using the required SINT form
440. s are Remarks Example Weighted Bit Value Number Error Conditions 1 0 Hardware error see AUXERR for more information 2 1 Calibration error 4 2 Trigger too fast error 8 3 Syntax error 16 4 Command not allowed from remote ADDRESS command 32 5 Undefined parameter received 64 6 Parameter out of range 128 7 Memory Error 256 8 Destructive overload detected 512 9 Out of calibration 1024 10 Calibration required 2048 11 Settings conflict memory improperly configured for sub sampling 4096 12 Math error divide by 0 integer overflow etc 8192 13 Subprogram error calling a deleted sub CONT with no PAUSE SUBEND or PAUSE only allowed in sub SCRATCH DELSUB CONT not allowed in sub 16384 14 System error The ERR command returns a 0 if no error bits are set e If bit 0 is set weight 1 refer to the auxiliary error register AUXERR command for more information e Executing the ERR command clears the status register s error bit bit 5 Related Commands AUXERR EMASK ERRSTR 10 OUTPUT 722 ERR m READS amp CLEARS ERROR REGISTER 20 ENTER 722 A ENTERS WEIGHTED SUM INTO VARIABLE A Chapter 6 Command Reference 177 ERRSTR ERRSTR EXTOUT Syntax Remarks Example Syntax 30 PRINT A PRINTS RESPONSE 40 END Error String Query The ERRSTR command reads the least significant set bit in either the error register or the auxiliary error register and then clears the bit
441. s directly to the GPIB You can however use any output format if the samples are first placed in reading memory see next remark To do this you should enable reading memory before executing the SSAC or SSDC command executing SSAC or SSDC does not change the output format to SINT when reading memory is enabled When sub sampling with reading memory enabled reading memory must be in FIFO mode must be empty executing MEM FIFO clears reading memory and the memory format must be SINT prior to the occurrence of the trigger arm event If not the multimeter generates the SETTINGS CONFLICT error when the trigger arm event occurs and no samples are taken For sub sampling the trigger event and the sample event are ignored these events are discussed in Chapter 4 The only triggering events that apply to sub sampling are the trigger arm event TARM command and the sync source event In sub sampling samples are taken on more than one period of the input waveform When the samples are sent directly to reading memory MEM command the multimeter automatically reconstructs the samples producing a composite waveform When the samples are sent to the output buffer the controller must use an algorithm to reconstruct the composite waveform Parameters for this algorithm are provided by the SSPARM command The effective_interval between samples and the total number of samples taken are specified by the SWEEP command You cannot use the NRDGS comm
442. s filter circuit to the input of the level detection circuitry The low pass filter has a 3dB point of 75 kHz and prevents high frequency components on the input signal from causing false triggers To enable level filtering send OUTPUT 722 LFILTER ON The level filter function can also reduce the multimeter s sensitivity to high frequency noise for frequency and period measurements or when making synchronous SETACV SYNC ACV or ACDCV measurements Digitizing can be done simply by specifying DC voltage measurements with a short integration time and a short interval between samples short relative to the frequency of the signal being digitized This is considered digitizing although the multimeter s track and hold circuit is not used The advantages of DCV digitizing over direct sampling discussed later are a lower noise level higher resolution up to 28 bits and a maximum sampling rate of 100 000 samples per second versus 50 000 for direct sampling The disadvantages of DCV digitizing are a greater amount of trigger jitter see the Specifications in Appendix A the inability to AC couple the input signal and a lower bandwidth input path of 150kHz vs 12MHz for direct or sub sampling Since the track and hold circuit is not used for DCV digitizing each sample is much wider a minimum of 500 nanoseconds versus 2 nanoseconds for direct or sub sampling DCV Remarks Note The PRESET DIG command configures the mul
443. s illustrate the error correction of auto calibration by computing the relative measurement error of the 3458A for various temperature conditions Constant conditions for each example are 10 V DC input 10 V DC range Tcal 23 C 90 day accuracy specifications Example 2 Operating temperature is 28 C With ACAL This example shows basic accuracy of the 3458A using auto calibration with an operating temperature of 28 C Results are rounded to 2 digits 4 1 ppm x 10 V 0 05 ppm x 10 V 42 pV Total relative error 42 nV Example 3 Operating temperature is 38 C Without ACAL The operating temperature of the 3458A is 38 C 14 C beyond the range of Tcal 41 C Additional measurement errors result because of the added temperature coefficient without using ACAL 4 1 ppm x 10 V 0 05 ppm x 10 V 42 pV Temperature Coefficient specification is per C 0 5ppm x 10V 0 01 ppm x 10V x 14 C 71 pV Total error 113 uV Example 4 Operating temperature is 38 C With ACAL Assuming the same conditions as Example 3 but using ACAL significantly reduces the error due to temperature difference from calibration temperature Operating temperature is 10 C beyond the standard range of Tcal 5 C 4 1 ppm x 10 V 0 05 ppm x 10 V 42 pV Temperature Coefficient specification is per C 0 15ppm x 10V 0 01ppm x 10V x 10 C 164V Total error 58 pV Appendix A Specifications Example 5 Ab
444. s secured the calibration number is also incremented by 1 whenever an autocal is performed if unsecured autocal does not affect the calibration number The calibration number is stored in cal protected memory and is not lost when power is removed The multimeter was calibrated before it left the factory When you receive the multimeter read the calibration number to determine its initial value e Related Commands CAL CALSTR SCAL 10 OUTPUT 722 CALNUM READS CALIBRATION NUMBER 20 ENTER 722 A ENTERS RESPONSE INTO COMPUTER 30 PRINT A PRINTS RESPONSE 40 END Calibration String remote only Stores a string in the multimeter s nonvolatile calibration RAM Typical uses for this string include the multimeter s internal temperature at the time of calibration TEMP command date of calibration technician s name and the scheduled date for the next calibration Chapter 6 Command Reference 165 COMPRESS Syntax string security_code Remarks Examples COMPRESS Syntax name Remarks CALSTR string security_code This is the alpha numeric message that will be appended to the calibration RAM The string parameter must be enclosed in single or double quotes The maximum string length is 75 characters the quotes enclosing the string are not counted as characters When the calibration RAM is secured SECURE command you must include the security_code in order to write a message to the calibration RAM
445. s the period of time that the A D converter measures the input signal For DC or ohms measurements the integration time determines the measurement speed accuracy maximum digits of resolution and the amount of NMR for noise at the A D converter s reference frequency You can specify integration time in terms of power line cycles PLCs using the NPLC command or directly in seconds using the APER command Since the NPLC and APER commands both set the integration time executing either will cancel the integration time previously established by the other The multimeter achieves NMR for noise at the A D converter s reference frequency when the integration time is gt 1 power line cycles You can specify integration time in terms of power line cycles PLCs using the NPLC command The multimeter multiplies the specified number of PLCs by the period of the A D converter s reference frequency LFREQ command to determine the integration time For example the period of a 50 Hz power line is 1 50 20 msec If you specify 10 PLCs the integration time is 200 msec In the power on state integration time is set to 10 PLCs In the PRESET NORM state integration time is set to 1 PLC To set the integration time for the fastest measurements with the lowest accuracy lowest resolution and no NMR send OUTPUT 722 NPLC 0 To specify the most accuracy highest resolution and 80dB of NMR for DC or ohms measurements with the slowest measurement speed
446. saaniesvan hidlevesnetistaes 123 FILTER seccassedevesncderwsqaesrncat ievncantedecestecewaaaienet 124 RMS aiena 125 Measuring Temperature 0 00 0 eeeeeseeteeeneees 125 Chapter 5 Digitizing TnitrOdUCHOM jistecntatectecstieiiies nesta Rika 129 Digitizing Methods 00 cceececceseeseeneeeeeeeeeeeeees 129 The Sampling Rate 00 eeeceeeeseeseeeeeeeceeeeeeeees 131 Level Triggering vise ciseessevacsasssvecxiessventssvasatasseeazess 132 Level Triggering Examples eceeeeeeeees 132 Level Falterin g werrenn 134 DEV Digitizing oneri 134 DCV Remarks 0 0 ceeeceeseecetececeeseeeeceseeaeeaeees 135 DCV Example siron n as 136 Direct Sampling eeseseseeeseeessessissssressesesessesrssees 137 Direct Sampling Remarks nsss 138 Direct Sampling Example ssseeeseseeeeeeeee 139 Sub Sampling seseesoeeeeeeseesoreesessesosessesesssseresses 139 Sub Sampling Fundamentals cece 140 The Sync Source Event cccccseeseeteeerees 141 Sub Sampling Remarks ssssseseessesseeeeeeeseeeee 143 Sending Samples to Memory cseeceeeeee 144 Sending Samples to the Controller 0 0 0 0 144 Viewing Sampled Data ce ceeeeeeeseeseeneeeeees 146 Chapter 6 Command Reference Introduction siie ienris uinen 151 Language Conventions cccccscceeeteeereeees 152 Command Termination s sssssseeeeseeeeeeseeeeseese 152 Multiple Commands cccccsceeseesteeteeeteeees 152 Parameters oiie iicisssachevldivieciiect
447. scecssseeeseeeeneeeeeeeeees 322 State Stora penin n staa an eaae aiai 322 Reading Analysis c cccsccsccesseeeseetteesteeeeees 322 Task Grouping and Sequence ceeseeeees 322 System Uptime cccccccesescecetecereeeteeeeessees 323 PULPOSE visas ccncebeeh coi fovea bevh ute a wenn de elantenades 323 Topics Covered in the Product Note include 323 DC Volts DC Current and Resistance 323 Optimizing Through the DCV Path 0 0 324 DC Current inosine ceiien iiai 326 Resistanee semen ani e nade das es 326 Optimizing Through the Track and Hold Path Direct Sampling and Subsampling 328 AC Volts and AC Current oseese 328 Analog ACW ninnan aiaa 328 Synchronous ACV ccccccssecseeteeeteeeteeteetees 328 Random ACV erindum aaa an 328 Comparison of ACV Modes esccesseeeeees 329 AC Current eei gi et eniti ear aarts 329 Frequency and Period ccceceesceeseeereerteeenes 330 Optimizing the Testing Process Through Task Allocation 3 shag iia aioe e a a dies 330 Math Operations cccceccceseeseeteeeteeeteeeeeees 330 Data Storage secanta en nani hai 330 Output Formats ssssssesseeesesessesssesseessessesseess 331 State Storage and Program Memory 331 Measurement List sssssseseeeeeeeeseeseseeseserresese 332 A Benchmark 00 eceeeecceseceeeeeeeeeeeeneeeeeeeeeeees 333 Benchmark Results cececeseeeeeeeseeteeteeeee 334 Still Faster ins Qu neceved
448. se some of the programming burden for lengthy set ups State Memory and other subprograms may be called from Program Memory Appendix D Optimizing Throughout and Reading Rate 331 Measurement List The most efficient method of using the 3458A within a system is to establish a 332 measurement list in Program Memory that corresponds with a channel list in the signal switching instrument The 358A s External Output is connected to the Channel Advance input of the switching instrument and the Channel Closed output of the switching instrument is connected to the External Trigger input of the 3458A Regardless of how long it takes to close a channel or make the measurement the channel is always closed and the measurement is always had time for completion without programming additional WAIT statements or added delay Further the reduction in GPIB data messages results in faster more convenient programming In the Figure 48 the circuit is tested to show the interaction of the 3458A with a switching unit the 3488A using External Trigger and External Output The measurements are simple AC and DC Volts and resistance In this case the time to change a function or a range is important to the test set up because the channel closure is relatively slow the 3488A uses very versatile but slow armature relays with switching speeds of about 25 ms per channel closure therefore multiple measurements are made on a test point If reed relays were used it woul
449. se the multimeter is in the remote mode as indicated by the display s REM annunciator and is ignoring all but the Local key To return the multimeter to local mode press Chapter 3 Configuring for Measurements Introduction seirene neesii i ie 47 General Configuration ccccccescceseeseeeteetteensees 47 Self Test Aeon een eie eas kane a Ta e 47 Reading the Error Registers eccesseeeereeeee 48 Calibration cs 2 2c icciaeeetaadceeecsdgecededded iebendedeeds 48 Autocalibration ececesceeeseereeeeeneeeeeeees 48 Running Autocal ccecccecssesteceteceeeeteeees 49 When to Use Autocal sosesc 49 Selecting the Input Terminals 0 cece 50 Giardino epaien nae a eana aa en i a 51 Suspending Readings ccccesceseeeseeeseeeteeeees 51 Presetting the Multimeter eeeeeereeeeeeee 52 Specifying a Measurement Function 53 AMUOTAN GE erien neei e seeviattevwsentan cote 53 Specifying the Range cccecceeeseesseeeeeeteeeeees 54 Configuring for DC or Resistance Measurements 54 DON Ota SG sone E 54 DC Current oiiire teie dette cede apadi eies 55 Resistance erasua ne aaa aeaa 56 2 Wire Ohms sssssssesssssssessesessesesrrsrssrsesssseee 57 4 Wire ODMS dorrir ran rar a arenes 57 Configuring the A D Converter 0 0 0 58 The Reference Frequency ccseseesteees 58 Setting the Integration Time eee 59 Specifying Resolution ccceeceeseereees 60 AULOZCLO esis e
450. send OUTPUT 722 NPLC 1000 You can specify power line cycles in the following ranges e 0 1 PLC in 000006 PLC steps for 60Hz ref frequency or 000005 PLC steps for 50Hz ref frequency e 1 10 PLC in 1 PLC steps e 10 1000 PLCs in 10 PLC steps For integration times greater than 10 PLCs the multimeter averages a number of readings made using 10 PLCs of integration time For example if you specify 60 PLCs the multimeter averages six 10 PLC readings The wide range of PLC settings provides flexibility in the selection of measurement speed accuracy resolution and NMR Typically you should Chapter 3 Configuring for Measurements 59 Specifying Integration Time Directly Note Specifying Resolution select the integration time that provides adequate speed while maintaining an acceptable amount of resolution and NMR The specifications tables in Appendix A show the relationship of integration time to digits of resolution and NMR for DC and ohms measurements For DC or ohms measurements you can specify the integration time directly in seconds using the APER aperture command For example to specify 22 ms of integration time send OUTPUT 722 APER 022 When using the APER command the multimeter does not average readings for long integration times as it does with the NPLC command For example if you specify 60 PLCs 1 second of integration time at a 60 Hz line frequency using the NPLC comman
451. ses the default level triggering for the sync source event trigger from input signal 0 AC coupling positive slope Line 120 generates a SYN event and transfers the samples directly to the computer Lines 240 through 410 sort the sub sampled data to produce the composite waveform The composite waveform is stored in the Wave_form array 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_samples Inc 1I J K L DECLARE VARIABLES 30 Num_samples 1000 DESIGNATE NUMBER OF SAMPLES 40 Eff int 2 0E 6 DESIGNATE EFFECTIVE INTERVAL 50 INTEGER Int_samp 1 1000 BUFFER CREATE INTEGER BUFFER 60 ALLOCATE REAL Wave _form 1 Num_samples CREATE ARRAY FOR SORTED 70 DATA ALLOCATE REAL Samp 1 Num_samples CREATE ARRAY FOR SAMPLES 80 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 90 ASSIGN Int_samp TO BUFFER Int_samp ASSIGN BUFFER I O PATH NAME 00 OUTPUT Dvm PRESET FAST LEVEL SLOPE SSRC LEVEL SSDC 10 01 FAST OPERATION TARM SYN LEVEL SYNC SOURCE OV POSITIVE SLOPE 05 DEFAULT VALUES SUB SAMPLING SINT OUTPUT FORMAT 10V RANGE 10 OUTPUT Dvm SWEEP Eff_int Num_samples 15 2us EFFECTIVE INTERVAL 1000 SAMPLES 20 TRANSFER Dvm TO Int_samp WAIT SYN EVENT TRANSFER READINGS INTO 21 INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS 25 SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED Chapter 6 Command Reference 30 40 50 60 70 80 90 90 200 210 220 230
452. signal To following program line enables the APER event with positive polarity see Figure 20 OUTPUT 722 EXTOUT APER POS Service Request When specified the service request event SRQ event produces a 1 us pulse whenever the multimeter generates a GPIB service request This event can be used to indicate to external equipment especially equipment that cannot be connected to GPIB that one or more specified events have occurred and have generated a service request refer to Using the Status Register in Chapter 3 for information on service requests Note When a status event sets the SRQ bit in the register that bit remains set until cleared CSB command for example When specified the EXTOUT SRQ pulse occurs whenever any status event occurs that has been enabled 114 Chapter 4 Making Measurements 10 20 30 40 50 60 70 80 90 100 110 120 130 EXTOUT ONCE OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT OUTPUT to assert SRQ RQS command The EXTOUT SRQ pulse does not necessarily occur whenever the SRQ bit is set it occurs whenever an enabled status event occurs The following program uses the SRQ event to synchronize the multimeter to external equipment The program downloads a subprogram to the multimeter When the subprogram is called by the controller line 120 it configures the multimeter for high accuracy temperature measurements using a 10k Q thermistor After the subprogram has bee
453. sing the ASCII output format and multiple readings are recalled from reading memory using the RMEM command the multimeter places a comma between readings In this case the cr f occurs only once following the last reading in the group being recalled Commas are not used when readings are output directly to the bus reading memory disabled when readings are recalled using implied read or when using any other output format e Check your computer manual for information on how your computer responds to the EOI line e If END ALWAYS is specified for the high speed mode the EOI mode automatically becomes ON while the readings are being taken Following completion of the readings the EOI mode returns to ALWAYS Refer to Increasing the Reading Rate in Chapter 4 for more information on the high speed mode e Query Command The END query command returns the present EOI mode Refer to Query Commands near the front of this chapter for more information Related Commands OFORMAT Example OUTPUT 722 END ALWAYS ENABLES GPIB EOI 176 Chapter 6 Command Reference ERR ERR Error Query When an error occurs it sets a bit in the error register and illuminates the display s ERR annunciator The ERR command returns a number representing all set bits clears the register and shuts off the annunciator The returned number is the weighted sum of all set bits Syntax ERR Error Conditions The error conditions and their weighted value
454. solute Accuracy 90 Day Assuming the same conditions as Example 4 but now add the traceability error to establish absolute accuracy 4 1 ppm x 10 V 0 05 ppm x 10 V 42 nV Temperature Coefficient specification is per C 0 15ppm x 10V 0 01ppm x 10V x 10 C 16nV Keysight factory traceability error of 2 ppm 2 ppm x 10 V 20 pV Total absolute error 78 uV Additional errors When the 3458A is operated at power line cycles below 100 additional errors due to noise and gain become significant Example 6 illustrates the error correction at 0 1 PLC Example 6 operating temperature is 28xC 0 1 PLC Assuming the same conditions as Example 2 but now add additional error 4 1 ppm x 10 V t 0 05 ppm x 10 V 42 nV Referring to the Additional Errors chart and RMS Noise Multiplier table additional error at 0 1 PLC is 2 ppm x 10 V 0 4 ppm x 1 x 3 x 10 V 32 nV Total relative error 74 uV 283 1 DC Voltage DC Voltage 2 Range Full Scale Maximum Input Impedance Temperature Coefficient ppm of 3 Resolution Reading ppm of Range C Without ACAL With ACAL 4 100mV 120 00000 10 nV gt 10 GQ 1 2 1 0 15 1 1V 1 20000000 10 nV gt 10 GQ 1 2 0 1 0 15 0 1 10 V 12 0000000 100 nV gt 10 GQ 0 5 0 01 0 15 0 01 5 100 V 120 000000 l1 uV 10MQ 1 2 0 4 0 15 0 1 1000 V 1050 00000 10 uV 10MQ 1 2 0 04 0 15 0 01 Accuracy ppm of Reading p
455. stablished by the other The RES command or the resolution parameter of a function or RANGE command can also be used to indirectly select an integration time An interaction occurs between APER or NPLC when you specify resolution as follows If you send the APER or NPLC command before specifying resolution the multimeter satisfies the command that specifies greater resolution more integration time If you send the APER or NPLC command after specifying resolution the multimeter uses the integration time specified by the APER or NPLC command and any previously specified resolution is ignored Query Command The APER query command returns the currently specified integration time in seconds used by the A D converter The integration time may have been specified by the APER NPLC or RES command or by the _resolution parameter of a function command or the RANGE command Refer to Query Commands near the front of this chapter for more information e Related Commands FUNC NPLC RANGE RES OUTPUT 722 APER 10E 6 SETS APERTURE TO 10 MICROSECONDS ARANGE Syntax control Autorange Enables or disables the autorange function ARANGE control The control parameter choices are 160 Chapter 6 Command Reference Remarks Example AUXERR Numeric control Query Parameter Equiv Description OFF 0 Disables autorange algorithm ON 1 Enables autorange algorithm ONCE 2 Causes the multimeter to autorange once the
456. state when it receives its listen address e In most cases you will only need the REMOTE command after using the LOCAL command REMOTE is independent of any other GPIB activity and is sent on a single bus line called REN Most controllers set the REN line true when power is applied or when reset Appendix B GPIB Commands 305 SPOLL Serial Poll Examples REMOTE 7 SETS GPIB REN LINE TRUE The above line does not by itself place the multimeter in the remote state The multimeter will only go into the remote state when it receives its listen address e g sending OUTPUT 722 BEEP REMOTE 722 SETS REN LINE TRUE AND ADDRESSES DEVICE 22 The above line places the multimeter in the remote state SPOLL Serial Poll 306 Syntax Status Register Bits Remarks Examples The SPOLL command like the STB command multimeter command set returns a number representing the set bits in the status register status byte The returned number is the weighted sum of all set bits P SPOLL 722 The bits and their corresponding weights are Bit Decimal Number Weight Description 0 1 Subprogram execution completed 1 2 Hi or lo limit exceeded 2 4 SRQ command executed 3 8 Power on SRQ occurred 4 16 Ready for Instructions 5 32 Error consult error register 6 64 Service requested 7 128 Data available e If the SRQ line is set true when you send SPOLL all bits in the status register are cleared provi
457. stem s up time is also increased as a result of the increased reliability of its components the 3458A s reliability is a product of Keysight s 10 X program of defect reduction Through environmental abuse and stress testing during the design stages of product development Keysight has reduced the number of defects and early failure in its instruments by a factor of ten over the past ten years Purpose The purpose of this Product note is to illustrate how you can use the revolutionary speed and accuracy of the 3458A Multimeter to achieve the best possible test throughput and reading rates for your application This is achieved by providing an explanation of the trade offs offered by the instrument and its optimal use with the HP 9000 Series 200 300 computers To ics Covered in DC measurements Volts current ohms the available trade offs of speed p the Product Note resolution and accuracy for their optimal use in your test system include e AC measurements analog ACV synchronous ACV random ACV current choosing the best mode and specifications for your application e frequency and period selecting gate time to achieve desired speed accuracy or resolution optimizing the testing process through task allocation using built in math functions or post processed math the readings memory states memory and Program Memory to best organize and allocate tasks between the dmm and the computer with program examples
458. t 101 SRQ 27 235 annunciator 27 SSAC 236 SSDC 236 SSPARM 239 SSRC 239 SSTATE 243 Standard queries 37 query commands 153 Stands tilt 20 State memory using 74 power on 25 State key recall 33 store 33 Statement ENTER 42 OUTPUT 42 TRANSFER 42 Statements Input output 42 States deleting 75 recalling 74 storing 74 Statistics 122 Status register 75 reading the 77 STB 244 Store State key 33 Storing states 74 subprogram 71 SUB 245 SUBEND 247 Subprogram autostart 73 executing 72 execution suspending 72 memory using 71 storing 71 Subprograms compressing 73 deleting 74 nested 73 Sub Sampling 139 Sub sampling 143 fundamentals 140 remarks 143 Suspending readings 51 subprogram execution 72 SWEEP 247 Switch lockout caps 311 power 25 Switches setting the line voltage 18 Sync source event 141 Synchronous ACDCV example fast 106 ACV example fast 106 readings 84 sampling conversion 63 sampling remarks 63 T T 250 TALK annunciator 27 Talk Only Mode 159 TARM 250 TBUFF 252 TEMP 253 Temperature measuring 125 TERM 253 Terminals selecting the input 50 Termination INDEX 371 command 152 output 99 TEST 254 Test key 30 test display 32 tilt stands 20 Time delay 105 Timed readings 85 TIMER 254 TONE 255 Transfer across GPIB high speed 107 from memory high speed 108 TRANSFER statement 42 TRIG
459. t MMATH PFAIL or MMATH STAT as described under the MMATH command When two real time math operations are enabled operation_a is performed on the reading first Next operation_b is performed on the result of the first operation When a real time math operation is enabled the display s half digit becomes a full digit For example if you are making 4 5 digit AC voltage measurements and then enable the SCALE math operation the display is capable of showing 5 full digits Math registers may be written to with the SMATH command Math registers may be read with the RMATH command Query Command The MATH query command returns two responses separated by a comma which indicate the enabled real time math function s Refer to Query Commands near the front of this chapter for more information Related Commands MMATH RMATH SMATH Chapter 6 Command Reference 195 MCOUNT MCOUNT MEM Example Syntax Remarks Example Syntax The following program performs the real time NULL math operation on 20 readings After executing the NULL command the first reading is triggered by line 50 The value in the OFFSET register is then changed to 3 05 The 20 read ings are triggered by line 90 and 3 05 is subtracted from each reading 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 20 DIMENSION ARRAY FOR 20 READINGS 30 OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 UTPUT 722 MATH NULL ENABLE REAL TI
460. t compensated Ohms makes a measurement of the input resistance without the current applied to measure any thermally generated DCV offsets As shown in Figure 46 the current is applied the offset voltage is subtracted from the measurement of the unknown resistance and the result is presented to the display Like auto zero it takes two measurements to make a final determination of the unknown resistance In reality offsets like this are only encountered in lower values of resistance The 3458A offers a 10 mA current source that will at least mask the effect of the thermally generated offset Hence in many cases Offset Compensated Ohms may not be needed for lower resistance measurements Figure 46 Offset compensated ohms removes the effect of small series voltage sources such as thermocouple effects in the circuit By measuring the voltage across the unknown resistance Ve with the current source off and then measuring the voltage across the unknown resistance with the current source on the effect of Ve on the measurement is eliminated Appendix D Optimizing Throughout and Reading Rate 327 Optimizing Through the Track and Hold Path Direct Sampling and Subsampling As stated earlier the standard DCV path directs the signal to the A to D Converter This path exhibits 150 kHz bandwidth and selectable resolution from 4 1 2 to 8 1 2 digits The track and hold path exhibits 12 MHz bandwidth and 4 1 2 digits of resolution
461. t stored The first parameter in the RMEM command specifies the beginning reading first parameter The second parameter count specifies the number of readings to be recalled starting with first The third parameter record specifies the record from which to recall readings Records correspond to the number of readings specified in the NRDGS or SWEEP command For example if you have specified four readings in the NRDGS command each record in reading memory contains four readings The following program specifies 10 readings per trigger NRDGS 10 and uses the TARM SGL command to take 8 groups of 10 readings multiple trigger arming This will place a total of 80 readings 96 Chapter 4 Making Measurements in memory 10 OUTPUT 722 TARM HOLD SUSPEND READINGS 20 OUTPUT 722 DCV 1 DC VOLTAGE 1V RANGE 30 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 40 OUTPUT 722 TRIG AUTO AUTO TRIGGER EVENT 50 OUTPUT 722 NRDGS 10 AUTO 10 READINGS TRIGGER AUTO SAMPLE EVENT 60 OUTPUT 722 TARM SGL 8 ARM TRIGGERING 8 TIMES 70 END The stored readings can now be accessed by individual reading number 1 through 80 or by record reading number e g the 3rd reading in record 2 is also reading number 13 For example the following program returns and displays reading number 50 the 31st reading taken by the above program 10 OUTPUT 722 RMEM 50 RECALL READING NUMBER 50 20 ENTER 722 A ENTER READING 30 PRINT A PRINT READING
462. t the lead resistance will not change If you disable autozero before making the 4 wire connections or if you have a varying lead resistance with autozero disabled such as when scanning you may get Chapter 3 Configuring for Measurements 61 Offset Compensation Fixed Input Resistance inaccurate 4 wire ohms measurements Because a resistance measurement involves measuring the voltage induced across the resistance any external voltage present offset voltage will affect the measurement accuracy With offset compensation enabled the multimeter corrects resistance measurements by canceling the effects of the offset voltage To do this the multimeter first measures the input voltage with its current source on The current source is then disabled and the input voltage measured again The true induced voltage is the difference between the two measured voltages You can use offset compensation for both 2 wire and 4 wire ohms measurements The multimeter can only perform offset compensation on the 10Q through 100kQ ranges offset compensation does not function on the other ranges In the power on PRESET NORM state offset compensation is disabled To enable offset compensation send OUTPUT 722 OCOMP ON Refer to the Appendix A for specifications concerning the maximum series offset voltage for offset compensated ohms measurements When making DC voltage measurements you can fix the multimeter s input resistance using the FIXEDZ comma
463. ta from remote Since front panel operation is discussed first it covers important topics such as the power on state display annunciators the various ways to select or enter parameters and how to make a simple DC voltage measurement For this reason you should read the entire chapter even if you intend to use the multimeter primarily from remote Before Applying Power Applying Power Power On Self Test Power On State Make sure the line voltage selection switches on the multimeter s rear panel are set to match the local line voltage e Make sure the proper line fuse is installed If you have any questions concerning installation or power requirements refer to Chapter 1 To turn on the multimeter depress the front panel Power switch If the multimeter does not appear to turn on verify that the multimeter is connected to line power If line power is not the problem remove the power cord and check the line power fuse and the line voltage selection switch settings When power is applied the multimeter performs a limited power on self test This test verifies that the multimeter is operating but does not necessarily verify that measurements will be accurate When the power on self test is finished the multimeter beeps once automatically triggers automatically selects the range and performs DC voltage measurements Also the multimeter has set many of its commands to predefined power on values as shown in Table 5 This is
464. tain up to 10 characters The name can be alpha alphanumeric or an integer from 0 to 127 When using an alphanumeric name the first character must be alpha Alpha or alphanumeric subprogram names must not be the same as multimeter commands or parameters or the name of a stored state The characters _ and can also be included in an alpha or alphanumeric name When using an integer subprogram name 0 127 the multimeter assigns the prefix SUB to the integer when the subprogram is stored This differentiates an integer subprogram name from an integer state name For example a sub program stored with the name 5 will be recorded as SUB 5 The subprogram can be accessed later using either the name 5 or SUB 5 A subprogram named 0 zero is designated the autostart subprogram see 7th Remark following Power on name none Default name none parameter required Subprogram entry is terminated by the SUBEND command The CALL command is used to execute a subprogram and the PAUSE and CONT commands suspend and resume subprogram execution respectively e When you store a new subprogram using the name of an existing subprogram the new subprogram overwrites replaces the old subprogram Entering storing a subprogram from the front panel is not recommended since front panel utilities e g up and down arrows can inadvertently be stored in the subprogram Once you have executed the SUB command from the front panel the display shows
465. te ACST send OUTPUT 722 PURGE ACST1 You can also use the SCRATCH command to delete all stored states and all subprograms from memory Using the Input Buffer In the multimeter s power on PRESET NORM state the input buffer is disabled The means the multimeter must process each GPIB command individually and wait until the command is executed before releasing the GPIB bus or accepting another command In most cases the controller must wait until the bus is released before it can continue which ensures synchronization between the controller and the instrument This is most noticeable on commands that take a long time to execute For example if you run the complete self test from remote TEST command the multimeter does not release the GPIB bus until the self test is complete approximately 50 seconds With the input buffer enabled the multimeter temporarily stores commands in the buffer and immediately releases the GPIB bus The multimeter then retrieves and executes the commands in the order received one by one from the input buffer This allows the controller to perform other operations while the multimeter is executing commands The following program enables the input buffer prior to executing the TEST command 10 OUTPUT 722 INBUF ON 20 OUTPUT 722 TEST 30 END The input buffer holds a maximum of 255 characters If you send more characters than the input buffer can hold the multimeter holds the bus until buffer
466. ted by each Table 11 Measurement Function Parameters Function Parameter Description ACDCI Selects AC current measurements DC coupled ACDCV Selects AC voltage measurements DC coupled ACI Selects AC current measurements AC coupled ACV Selects AC voltage measurements AC coupled DCI Selects DC current measurements DCV Selects DC voltage measurements DSAC Direct sampling AC coupled DSDC Direct sampling DC coupled FREQ Selects frequency measurements OHM Selects 2 wire ohms measurements OHMF Selects 4 wire ohms measurements PER Selects period measurements SSAC Sub sampling AC coupled SSDC Sub sampling DC coupled Refer to Chapter 5Digitizing for more information on these functions When the autorange function is enabled the multimeter samples the input prior to each reading when readings are being triggered and automatically selects the correct range Since autorange requires sampling the input measurements made with autorange enabled take longer than measurements made on a fixed range In the power on PRESET NORM state autorange is enabled If you intend to measure a fairly stable input signal you can use the ARANGE ONCE command to allow autorange to select the correct range when readings are triggered and then disable autorange for subsequent readings This allows you to get the automatic range selection advantage of autorange and also the speed advantage of readings made with autorange disabled To do this send Chapter
467. ter The STB status byte command returns a number representing the set bits The returned number is the weighted sum of all set bits STB The status register conditions and their weights are Decimal Bit Weight Number Status Register Condition 1 0 Subprogram Execution Completed 2 1 Hi or Lo Limit Exceeded 4 2 SRQ Command Executed 8 3 Power On 16 4 Ready for Instructions 32 5 Error Consult Error Register 64 6 Service Requested you cannot disable this bit 128 7 Data Available e When you execute the STB Command the ready bit bit 4 is always clear not ready because the multimeter is processing the STB command The CSB command clears the status register bits 4 5 and 6 are not cleared if the condition s that set the bit s still exist The RQS command designates which status register conditions will assert SRQ on the GPIB bus Related Commands CSB EXTOUT RQS SPOLL GPIB command 10 OUTPUT 722 STB RETURNS THE WEIGHTED SUM OF ALL SET BITS 20 ENTER 722 ENTERS RESPONSE INTO COMPUTER S A VARIABLE 30 PRINT A PRINTS RESPONSE 40 END Assume the above program returns the weighted sum 24 This means the bits with weighted values 8 power on and 16 ready for instructions are set Chapter 6 Command Reference 245 SUB SUB 246 Syntax Remarks Subprogram Stores a series of commands as a subprogram and assigns the sub program name SUB name name Subprogram name A subprogram name may con
468. ter a negative edge transition on the Ext Trig input followed by the controller requesting data which satisfies both SYN events the first reading is taken One reading is then taken per SYN event until the specified number of readings are completed EXT SYN AUTO EXT TIMER After a negative edge transition on the Ext Trig input LINE LEVEL followed by the controller requesting data one reading is taken per sample event until the specified number of readings are completed HOLD Any Any No readings taken until the trigger arm event is changed AUTO EXT HOLD Any No readings taken until the trigger event is changed When SGL SYN using the SGL trigger arm event and the SYN sample event the input buffer must be enabled or you must suppress cr If when sending the TARM SGL command SGL AUTO Any After executing the TARM SGL command one reading is taken per sample event until the specified number of readings are completed The trigger arm event then becomes HOLD When using the SYN sample event the input buffer must be enabled or you must suppress cr If when sending the TARM SGL command SGL EXT AUTO EXT TIMER After executing the TARM SGL command followed by a LINE LEVEL negative edge transition on the Ext Trig input one reading is taken per sample event until the specified number of readings are completed The trigger arm event then becomes HOLD SGL EXT SYN Illegal SGL LEVEL AUTO EXT TIMER After executing the TARM SGL
469. ter choices are Numeric event Query Parameter Equiv Description AUTO 1 Triggers whenever the multimeter is not busy EXT 2 Triggers on low going TTL signal on the Ext Trig connector SGL 3 Triggers once upon receipt of TRIG SGL then reverts to TRIG HOLD HOLD 4 Disables readings SYN 5 Triggers when the multimeter s output buffer is empty memory is off or empty and the controller requests data LEVEL 7 Triggers when the input signal reaches the voltage specified by the LEVEL command on the slope specified by the SLOPE command LINE 8 Triggers on a zero crossing of the AC line voltage The LEVEL trigger event can be used only for DC voltage and direct sampled measurements The LINE trigger event cannot be used for sampled AC or AC DC voltage measurements SETACV RDDM or SYNC or for frequency or period measurements Power on event AUTO Default event SGL e For all measurements except sub sampling see Chapter 5 the trigger event operates along with the trigger arm event TARM command and the sample event NRDGS command The trigger event and the sample event are ignored for sub sampling To make a measurement the trigger arm event must occur first followed by the trigger event and finally the sample event The trigger event does not initiate a measurement It merely enables a measurement making it possible for a measurement to take place The measurement is initiated when the sample event NRDGS or S
470. the 3458A transfers the wave form to the computer and plots the wave form on the computer s CRT It uses four Library subprograms Setup_dig the dmm setup subprogram that determines the way you are going to digitize the wave form DCV DSAC DSDC SSAC SSDC the time interval between samples and the number of samples if you plan on using the FFT or IFT routines the number of samples must be a power of two Wfdgtz the wave form capture subprogram Wfmove the transfer subprogram and Wfplot the plotting subprogram 1280 CALL Setup_dig 1 1 e 5 1000 1270 CALL Wfdgtz 1 1280 CALL Wfmove 1 98 Scal Wavf Clip 1290 CALL Wfplot Scal Wave form 1 Wavf 1 1 Appendix E High Resolution Digitizing With the 3458A Starter Main Program The subprogram is one of the most powerful elements available in any programming language Each subprogram has its own context or state as distinct from the main program This means that every subprogram has its own set of variables and its own line labels Every program using the library subprogram requires a main program Many of the data arrays discussed in this part must be dimensioned in each main program Additionally the COM statements used by many of the library subprograms are needed in most main programs Included with the Wave form Analysis Library is a starter main program that can form the beginning of all main programs as shown here 10 Main 20 Core main program programm
471. the ACBAND command Chapter 6 Command Reference 241 SSRC 242 Remarks Examples Power on mode AUTO Default mode AUTO For sub sampling the trigger event and the sample event are ignored The only triggering events that apply to sub sampling are the trigger arm event TARM command and the sync source event SSRC command For synchronous ACV or ACDCV measurements SETACV SYNC command the specified trigger arm event TARM command trigger event TRIG command and sample event NRDGS command must all be satisfied before the sync source event can initiate sampling For sub sampling and synchronous AC measurements bursts of samples are taken on more than one period of the waveform The sync source event synchronizes these bursts to the periods of the input signal that is a sync source event should typically occur once for each period e Query Command The SSRC query command returns two responses separated by a comma The first response is the present source The second response is the present mode Refer to Query Commands near the front of this chapter for more information Related Commands LEVEL LFILTER SETACV SYNC SLOPE SSAC SSDC In the program on the following page the SSAC command is used to digitize a 10 kHz signal with a peak value of 5V The SWEEP command instructs the multimeter to take 1000 samples Num_ samples variable with a 2us effective_interval Eff_int variable The measurement u
472. the completion of the subprogram or a PAUSE command discussed below is encountered Refer to Using the Input Buffer later in this chapter for information on how to release the bus immediately after calling a subprogram To abort subprogram execution send the GPIB Device Clear command From the front panel you can view all stored subprogram names by accessing the CALL command and pressing the up or down arrow key Once you have found the correct subprogram press the Enter key to execute the subprogram Suspending You can temporarily suspend subprogram execution by including the Subpro gram PAUSE command in the stored subprogram The multimeter executes subprograms on a command by command basis When it encounters the Execution PAUSE command subprogram execution is suspended and if the subprogram was called from remote the GPIB bus is released For example the following program has a PAUSE command in line 60 10 OUTPUT 722 SUB 2 20 OUTPUT 722 MEM FIFO 30 OUTPUT 722 TRIG HOLD 40 OUTPUT 722 DCV 10 50 OUTPUT 722 NRDGS 5 AUTO 60 OUTPUT 722 PAUSE 70 OUTPUT 722 TRIG SGL 80 OUTPUT 722 SUBEND END TAG When you call the above subprogram the commands will be executed up to the PAUSE command and then program execution ceases To resume subprogram execution send OUTPUT 722 CONT 72 Chapter 3 Configuring for Measurements Nested Subprograms Autostart Subprogram C
473. til it encounters TARM EXT line 70 Subprogram execution then ceases until an external trigger occurs This allows you to synchronize subprogram execution to some external event After the first external trigger is received subprogram execution resumes When the next line is encountered TRIG SGL subprogram execution ceases until the 1000 readings are taken After the readings are taken the subprogram changes the measurement function to 2 wire ohms and the number of readings to 100 When the second TARM EXT command is encountered line 100 subprogram execution ceases Chapter 6 Command Reference 247 SUBEND SUBEND SWEEP Syntax Remarks Example Syntax until another external trigger occurs After the external trigger is received the TRIG SGL command is encountered which suspends subprogram execution until the 100 readings are taken After the readings are taken the message TEST FINISHED is displayed 10 OUTPUT 722 SUB EXTPACE STORE LINES 20 110 AS SUBPROGRAM 20 OUTPUT 722 PRESET NORM PRESET SUSPEND READINGS 30 OUTPUT 722 MEM FIFO ENABLE READING MEMORY FIFO MODE 40 OUTPUT 722 DCV 10 DC VOLTAGE MEASUREMENTS 10V RANGE 50 OUTPUT 722 NRDGS 1000 AUTO 1000 READINGS TRIGGER AUTO SAMPLE EVENT 60 OUTPUT 722 TARM EXT EXTERNAL TRIGGER ARM EVENT 70 OUTPUT 722 TRIG SGL SINGLE TRIGGER EVENT 80 OUTPUT 722 OHM 1E3 2 WIRE OHMS 1kQ RANGE 90 OUTPUT 722 NRDGS 100 AUTO 100 READINGS
474. timeter for DC voltage measurements with a sampling rate of 50 000 samples per second PRESET DIG selects a 3s integration time and level triggering when the input signal crosses zero volts on its positive slope The primary commands executed by PRESET DIG are TARM HOLD Suspends triggering TRIG LEVEL LEVEL trigger event LEVEL 0 AC Level trigger at 0 of range 0V AC coupled TIMER 20E 6 20us interval between samples NRDGS 256 TIMER 256 samples per trigger TIMER sample event DCV 10 DC voltage measurements 10V range DELAY 0 No delay APER 3E 6 3us integration time MFORMAT SINT Single integer memory format OFORMAT SINT Single integer output format AZERO OFF Disables the autozero function DISP OFF Disables the display After executing PRESET DIG you can increase the sampling rate by decreasing the TIMER interval and by reducing the integration time using the APER command The minimum integration time for DCV is 500 nanoseconds e For DCV digitizing you should use the SINT memory output format when the integration time is lt 1 4us Use the DINT memory output format when the integration time is gt 1 4us These formats are discussed in detail in Chapter 4 To achieve the fastest possible transfer of samples to reading memory and or the controller you can use the SINT output memory format for integration times up to 10 8us However when the integration time is gt 1 4us the A D converter is
475. tion for the previous Edition Each new Edition or Update also includes a revised copy of this documentation history page Edito D ceo ege ood ache eaten Sa as Hee ee A Oe a May 1988 Upd te 3 lt rnc S55 hae Shao adie Astin te Sun AE EN ea en aes BG February 1992 i V1 C0 0 Wo peer ie tee cA ae ae October 1992 Editon aa aean atyai octet danas S E it aAA February 1994 Editon 4 0 eean 2B sce Quasars hess AE AEO EN O AE ey December 2000 Edi OMS se o OEE oa Be as E EATA ore AA ERE EE A May 2012 Editon Go 2 435 stg enire ob ea Pa Dea AE Sie S E April 2013 Edition o oee nea ato 8s Bae EEEE AAA e EE Sse August 2014 Safety Symbols Instruction manual symbol affixed to product Indicates that the user must refer to Ny Alternating current AC the manual for specific WARNING or CAUTION information to avoid personal leg es Direct current DC injury or damage to the product ety a Indicates the field wiring terminal that must AN WARNING RISC OP ELEC SHOCK be connected to earth ground before operating the equipment protects against electrical shock in case of fault Calls attention to a procedure practice or WARNING condition that could cause bodily injury or l Frame or chassis ground terminal typically death po or connects to the equipment s metal frame Calls attention to a procedure practice or condition that could possibly cause damage to equipment or permanent loss of data CAUTION WARNINGS The followi
476. tion install a 1 5A fuse For 220 VAC or 240 VAC operation install a 500 mAT fuse The line power fuse holder is located on the right side of the multimeter s rear panel see Figure 1 To install a fuse make sure the multimeter s power cord is removed Insert one end of the fuse into the fuse cap Insert the fuse cap assembly into the fuse holder With a small flatblade screwdriver push in on the fuse cap and rotate it clockwise Power Cords Figure 3 shows the various multimeter power cords and their Keysight part numbers If you received the wrong power cord notify your Keysight sales office for replacement 18 Chapter 1 Installation and Maintenance Power Cords ap SP eS Australia Denmark Europe Great Brittain Switzerland U S A U S A Country Part Number Option Voltage Australia 8120 1369 901 250V 6A Denmark 1820 2956 912 259V 6A Europe 1820 1689 902 250V 6A Great Brittain 1820 1351 900 250V 6A Switzerland 1820 2104 906 250V 6A United States 1820 1378 903 120 10A United States 1820 0698 904 240V 10A Power cords supplied by Keysight have polarities matched to the power input socket on the instrument NOTE Plugs are viewed from connector and Shape of molded plug may vary within country CSA certification includes only these power cords Figure 3 Power Cords Con necting the GPIB Attach the GPIB cable to the 24 pin GPIB connector on the rear panel of Cable the multimeter Finger tighten the two screws on th
477. tion time is the period of time that the A D converter measures the input signal For analog AC measurements the integration time determines the maximum digits of resolution and along with the specified bandwidth affects the measurement speed Integration time also has a minor affect on analog AC measurement accuracy Analog AC measurements are defined as AC or AC DC voltage measurements made using the analog conversion method SETACV ANA command only and AC or AC DC current measurements With longer integration times the measurement resolution and accuracy increases but measurement speed decreases The integration time has no effect on frequency or period measurements For sampled AC voltage measurements SET ACV SYNC or SET ACV RNDM the A D converter s integration time is selected automatically and the multimeter achieves the specified resolution Specifying Resolution is discussed in the next section by varying the number of samples taken For analog AC measurements you can specify integration time in terms of power line cycles PLCs using the NPLC command You can also use the APER command to specify integration time although it is primarily intended for DC measurements refer to the APER command in Chapter 6 for more information The multimeter multiplies the specified number of PLCs by the period of the A D converter s reference frequency LFREQ command to determine the integration time For example the period of a 5
478. tions except sub sampling see Chapter 5 the trigger arm event operates along with the trigger event TRIG command and the sample event NRDGS or SWEEP command To make a measurement the trigger arm event must occur first followed by the trigger event and finally the sample event The trigger arm event does not necessarily trigger the multimeter It merely enables the trigger event making it possible for the multimeter to respond to the trigger event Refer to Triggering in Chapter 4 for an in depth discussion of the interaction of the various events e Multiple arming When using multiple arming the trigger arm event must be specified as SGL When the multimeter executes a TARM command specifying multiple arming it holds the GPIB bus until all measurement cycles are complete For example if you specify number_arms as 5 and 10 readings per cycle NRDGS command there are 5 measurement cycles of 10 readings each Since it holds the bus the TARM command must be the last line in the program and you cannot use the synchronous trigger event or sample event Query Command The TARM query command returns the currently selected trigger arm event Refer to Query Commands near the front of this chapter for more information Related Commands NRDGS SWEEP TRIG OUTPUT 722 TARM AUTO 0 AUTO TRIGGER ARMING ALWAYS ARMED 10 OUTPUT 722 TARM HOLD SUSPENDS MEASUREMENTS 20 OUTPUT 722 OHM SELECTS 2 WIRE
479. to any terminal Keysight recommends that the wiring installer attach a label to any wiring having hazardous voltages This label should be as close to the input terminals as possible and should be an eye catching color such as red or yellow Clearly indicate on the label that high voltages may be present Caution The current input terminals I are rated at 1 5A peak with a maximum non destructive input of lt 1 25A RMS Current inputs are fuse protected The multimeter s input voltage ratings are Table 9 Input Ratings Rated Input Maximum Non Destructive Input HI to LO Input 1200V peak 50 Chapter 3 Configuring for Measurements Guarding Suspending Readings Table 9 Input Ratings Rated Input Maximum Non Destructive Input HI LO Q Sense to LO Input 200V peak 350V peak HI to LO Q Sense Input 200V peak 350V peak LO Input to Guard 200V peak 350V peak Guard to Earth Ground 500V peak 1000V peak HI LO Input HI LO Q Sense or 000V peak 1500V peak terminal to earth ground Front terminals to rear terminals OO0V peak I500V peak The multimeter will be damaged if any of the above maximum non destructive inputs are exceeded The measurement connection illustrations in this chapter show the multimeter s Guard terminal connected to the low side of the measurement source guarded measurements This configuration provides maximum effective common mode
480. tored You can re enable reading memory without destroying any stored readings using the MEM CONT command The multimeter assigns a number to each reading in reading memory The most recent reading is assigned the lowest number 1 and the oldest reading has the highest number Numbers are always assigned in this manner regardless of whether you re using the FIFO or LIFO mode Records are also numbered in this manner the most recent record is record number 1 When you execute the RMEM command from the front panel readings are copied one at a time to the display After viewing the first reading you can view others by using the up or down arrow key Use the left and right arrow keys to view the reading number left side of display and the reading right side of display e In addition to the RMEM command you can also recall readings using the implied read Refer to Recalling Readings in Chapter 4 for more information Related Commands MCOUNT MEM MFORMAT MSIZE NRDGS Example 10 OUTPUT 722 TARM HOLD SUSPENDS TRIGGERING 20 OUTPUT 722 DCV DC VOLTAGE MEASUREMENTS 30 OUTPUT 722 TRIG AUTO AUTOMATIC TRIGGERING 40 OUTPUT 722 NRDGS 3 AUTO 3 READINGS PER SAMPLE EVENT AUTO 50 OUTPUT 722 MEM FIFO ENABLES READING MEMORY FIFO MODE 60 OUTPUT 722 TARM SGL 10 10 GROUPS OF READINGS 70 OUTPUT 722 RMEM 1 3 6 READS 1ST 3RD READINGS of 6TH GROUP 80 ENTER 722 A B C ENTERS READINGS INTO A B amp C VARIAB
481. tored states or subprograms are stored A non integer subscript is rounded to the nearest integer Arrays may be resized by re declaring them This initializes each element in the array to a value of zero You cannot however redefine the type of array real or integer without scratching memory first refer to the SCRATCH command in chapter 6 Array elements may be used in the same ways simple variables are used Filling Arrays Array elements are initialized to zero when they are declared DIM REAL or INTEGER commands or are re sized Once you have dimensioned an array use the FILL command to load your values into the array The FILL command has the following syntax FILL array name list The following program fills an integer array with integer values 10 OUTPUT 722 INTEGER LIST 9 20 OUTPUT722 FILL LIST 0 100 200 300 400 500 600 700 800 900 30 END Note Use the FILL command carefully It does not work if power is cycled The command is effectively deleted from the subprogram at this time Use separate LET statements for each value assigned Array Size The SIZE query command returns the number of elements in the specified array This number is one more than the index of the last element in the array due to the option base 0 convention used by the 3458A Thus if you dimension a 10 element array e g DIM LIST 9 the SIZE command will return 10 The following program defines an integer array with 10 eleme
482. ubsampling SWEEP which is related to NRDGS and SSRC which selects the trigger source level or external for subsampling You can choose from a variety of events or conditions that must be satisfied before taking measurements as shown is Figure 54 The default condition for all three levels of triggering is AUTO the 3458A will generate its own trigger as fast as the multimeter set up allows AC Figure 54 The trigger event choices shown MAIN provide the versatility needed to match a wide variety of applications COUPLING A to D CONVERTER TARM is the first condition to be satisfied Its function is to arm the trigger circuit prior to receiving the trigger signal For example if a synchronizing signal were available external to the signal of interest then TARM EXT could be used to arm the 3458A to look for the trigger event Also TARM can be used to control multiple measurement sequences by adding the number of times you want a particular measurement cycle repeated For example TARM SGL 4 specifies that the trigger arming be applied four times and then stops Refer to Figure 55 Figure 55 Digitizing 10 OUTPUT 722 TARM HOLD Places the 3458 in a measurement hold condition with the standard 20 OUTPUT 722 TRIG EXT Sets the trigger event to triggering command trigger Trigger Arming TARM 30 OUTPUT 722 NRDGS 5 TIMER Sets up a burst of five SGL 4 allows a readings for every trigger
483. uery DCV 1V 1V 10V DCV 100V Parameters Equiv Description 1000V Ranges Ranges OFF 0 FIXEDZ gt 10 GQ 10 MQ disabled ON 1 FIXEDZ 10 MQ 10 MQ enabled Power on control OFF Default control ON Remarks FIXEDZ remains enabled when you change from DC voltage measurements to 2 wire or 4 wire ohms measurements Resistance measurements made with FIXEDZ enabled will be in error because the multimeter s input resistance represents a 10 MQ resistance in parallel with the input terminals FIXEDZ is temporarily disabled when you change from DC voltage measurements to AC voltage AC DC voltage any type of current frequency or period measurements For example if FIXEDZ is enabled and you change from DC voltage measurements to AC voltage measurements FIXEDZ becomes disabled When you return to DC voltage measurements however FIXEDZ is once again enabled Query Command The FIXEDZ query command returns the present fixed input resistance mode Refer to Query Commands near the front of this chapter for more information Related Commands DCV FUNC OHM OHMF Example OUTPUT 722 FIXEDZ ON ENABLES FIXED IMPEDANCE 180 Chapter 6 Command Reference FREQ Syntax max _input _resolution Remarks FREQ Frequency Instructs the multimeter to measure the frequency of the input signal You must specify whether the input signal is AC voltage AC DC voltage AC current or AC DC current using the FFOURCE command
484. ult effective_interval 20us samples Specifies the number of samples to be taken The valid range for this parameter is 1 to 1 67E 7 Power on _samples 1024 Default _samples 1024 The minimum effective interval for DC voltage measurements is 10us for direct sampling 20us for sub sampling 10 nanoseconds The SWEEP command can be used to replace the NRDGS n TIMER command and the TIMER command The SWEEP and NRDGS are interchangeable the multimeter uses whichever command was executed last in the programming Executing the SWEEP command automatically sets the sample event to TIMER In the power on RESET or PRESET state the multimeter uses the NRDGS command The power on values for SWEEP can only be used for sub sampling since NRDGS does not apply to sub sampling You cannot use the SWEEP or TIMER functions for AC or AC DC voltage measurements using the synchronous or random methods SETACV SYNC or RNDM or for frequency or period measurements When using the SWEEP command or TIMER event autoranging is suspended typically you should select a fixed range when using SWEEP Query Command The SWEEP query command returns two responses separated by a comma The first response is the specified effective_interval The second response is the specified _ samples Refer to Query Commands near the front of this chapter for more information Related Commands FUNC NRDGS TIMER In the program on the following pag
485. ultimeter s internal temperature in degrees Celsius 10 OUTPUT 722 TEMP 20 ENTER 722 A 30 PRINT A 40 END The autocal constants are stored in continuous memory they remain intact when power is removed Therefore it is not necessary to perform autocal simply because power has been cycled Selecting the Input The multimeter has both front and rear terminals for measurement Terminals connections The front panel Terminals switch allows you to select between the two depressed Rear out Front You cannot select the input terminals from remote The measurement connection illustrations in this chapter show the front terminal connections only For rear terminal connections connect each wire to the similarly labeled rear terminal We recommend high impedance low dielectric absorption cables for all measurement connections WARNING Only qualified service trained personnel who are aware of the hazards involved should remove or install the multimeter or connect wiring to the multimeter Disconnect the multimeter s power cord before removing any covers changing the line voltage selector switches or installing or changing the line power fuse Measuring high voltage is always hazardous All multimeter input terminals both front and rear must be considered as hazardous whenever inputs in excess of 42V are connected to any terminal Regard all terminals as being at the same potential as the highest voltage applied
486. ultimeter when used with the DSAC or DSDC command This parameter is allowed in the command syntax to be consistent with the other function commands FUNC ACT DCV etc e You cannot use autorange for direct sampled measurements you must specify the range as the first parameter of the DSAC or DSDC command max _input parameter e Notice that when using the DINT memory output format the full scale values for direct sampling are 500 5 times the ranges of 10mV 100mV 1V 10V and 100V This is particularly important to consider when specifying the percentage for level triggering When specifying the level triggering voltage use a percentage of the range For example assume the input signal has a peak value of 20V and you are using the 10V range If you want to level trigger at 15V specify a level triggering percentage of 150 LEVEL 150 command The slew rate of the multimeter s amplifiers may be exceeded when measuring a signal with a frequency gt 2MHz and an amplitude gt 120 of range signals lt 120 of range with frequencies up to 12MHz do not cause slew rate errors The multimeter s triggering hierarchy trigger arm event trigger event and sample event applies to direct sampling This means that these events must occur in the proper order before direct sampling begins Refer to Chapter 4 for more information on the triggering hierarchy For direct sampling you can use either the TIMER sample event and the NRDGS n TIMER comma
487. unction or integration time for 10 of the 37 measurements The others are measured in blocks in the same measurement configuration Fixed Range Subprogram Fixed time 15 98 s 840 SUB Fixed REAL Dnld_time Exe time Tns_ time 850 DIM A 37 860 Exe time TIMEDATE 870 OUTPUT 722 RESET TRIG SYN 880 OUTPUT 722 0OHM 1E4 890 FOR I 1 TO 15 900 ENTER 722 A I 910 NEXT I 920 OUTPUT 722 0HM 1E5 1110 ENTER 722 A TI 1120 NEXTI 1130 Exe time TIMEDATE Exe time 1140 Dnld time 0 1150 Tns_time 0 1160 SUBEND The test situation is the same as the default situation but the ranges are set to the range necessary for the measurement instead of auto range Correct integration time Subprogram Integrate time 3 76 s 1170 SUB Integrat REAL Dnld time Exe_time Tns_time 334 Appendix D Optimizing Throughout and Reading Rate 180 190 200 210 220 230 240 250 410 420 430 440 450 460 470 480 490 DIM A 37 Exe time TIMEDATE OUTPUT 722 PRESET OUTPUT 722 OHM 1E4 NPLC 0 FOR I 1 TO 15 ENTER 722 A I NEXT I OUTPUT 722 0HM 1E5 ENTER 722 A 34 OUTPUT 722 DCV 10 NPLC 0 FOR I 35 TO 37 ENTER 722 A I NEXT I Exe_time TIMEDATE Exe_time ld_time 0 Tns_time 0 SUBEND The test situation is the same as the fixed range situation but the integration time selected for each measurement is correct for the required resolution and accuracy instead of the default of 10PLC Correct dela
488. unction must be OHM or OHMF 10kQ range or higher Result reading OFFSET register The OFFSET register is set to first reading after that you can change it Result reading PERC register PERC register x 100 Reading vs MAX and MIN registers Result squares reading applies FILTER operation takes square root Result reading OFFSET register SCALE register Performs statistical calculations on the present set of readings and stores results in these registers SDEV standard deviation MEAN average of readings NSAMP number of readings UPPER largest reading LOWER smallest reading Result temperature Celsius of a 2kQ thermistor 40653A Function must be OHM or OHMF Result temperature Celsius of a 10kQ thermistor 40653C Function must be OHM or OHMF Result temperature Fahrenheit of a 2kQ thermistor 40653A Function must be OHM or OHMF Result temperature Fahrenheit of a 10kQ thermistor 40653C Function must be OHM or OHMF Result temperature Celsius of 100Q RTD with alpha of 0 00385 40654A or 40654B Function must be OHM or OHMF Result tempersture Celsius of 100Q RTD with alpha of 0 003916 Function must be OHM or OHMF Result temperature Fahrenheit of 100Q RTD with alpha of 0 00385 40654A or 40654B Function must be OHM or OHMF Result temperature Fahrenheit of 100Q RTD with alpha of 0 003916 Function must be OHM or OHMF Power on operation_a ope
489. ure was encountered are logged in the PFAILNUM register The default value is 0 for both the MAX and MIN registers You can change the value in either register using the SMATH command The following program uses the real time PFAIL operation to check 20 DCV readings against the high and low limits of 11V and 9V After the readings have been triggered the HI LO LIMIT bit of the status register bit 2 is checked If one or more failures occurred the PFAILNUM register is queried and its contents returned 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 DIM Rdgs 20 DIMENSION ARRAY FOR 20 READINGS 30 OUTPUT 722 PRESET NORM PRESET NRDGS 1 AUTO DCV 10 TRIG SYN 40 OUTPUT 722 MATH PFAIL ENABLE REAL TIME PFAIL OPERATION 50 OUTPUT 722 SMATH MIN 9 LOWER LIMIT 9 V 60 OUTPUT 722 SMATH MAX 11 UPPER LIMIT 11 V 70 OUTPUT 7227 CSB CLEAR STATUS REGISTER 80 OUTPUT 7227 ROS 2 ENABLE HI LO STATUS REGISTER BIT 90 OUTPUT 722 NRDGS 20 20 READINGS TRIGGER 100 ENTER 722 Rdgs SYN EVENT ENTER READINGS LLO OUTPUT 7227 STR QUERY SET BITS IN STATUS REGISTER 120 ENTER 722 A ENTER QUERY RESPONSE 130 IF BINAND A 2 THEN ITF BIT 2 IS SETS 140 PRINT HI LOW LIMIT TEST FAILED PRINT FAILURE MESSAGE 150 OUTPUT 722 RMATH PFAILNUM QUERY PFAILNUM REGISTER 160 ENTER 722 B ENTER QUERY RESPONSE 170 PRINT NUMBER OF READINGS THAT PASSED BEFORE FAILURE WERE B 175 PRINT PFAILNUM RESPONSE 180 ELSE IF BIT 2
490. ution Digitizing With the 3458A cycle Two methods suggest themselves for this analysis 1 sweep the entire frequency spectrum at 100 ns interval or 2 divide the frequency spectrum into bands and sweep these bands at the 1 2f for the band In the first case the data acquisition time is minimized in the second case the need for a fast computer is minimized Figure 57 Using the N OUT 3458A as a phase gain 3325A aT ss a g Vi E BAN L V out meter with a swept SIGNAL SOURCE FILTER i fr n nerator eque cy gene Computer Displa Computer Oispla for magnitude only Bode plots The DUT can be characterized over frequency with a phase synchronous Time trigger to time the measurement amp p Sk 3 a Magnitude Frequency High Speed Data Transfers Software Help The Wave Form Analysis Library The 3458A can transfer readings at its maximum reading rate to a 9000 Series 200 300 computer with a direct memory access card only the computer is set up to capture the data at this rate The readings can be taken from the 3458A internal memory or as the dmm is making the measurements Two conditions must occur the dmm has to be devoted to high speed readings and the proper buffers must be set up in the computer PRESET DIG is exactly the command needed for the 3458A It sets up the DMM for the highest speed possible As long as direct digitizing is the desired operation there is no prob
491. values nearly always results in more digits to the right of the decimal point than existed in either of the two numbers being multiplied The 3458A can store and execute BASIC language subprograms These subprograms can either be downloaded into 3458A memory from a remote system controller such as one of the HP Series 200 300 computers or you can enter the subprogram from the front panel keyboard This section acquaints you with the structure and usage of subprograms It also discusses specific commands which are used within subprograms A subprogram is a series of 3458A commands beginning with the SUB command and ending with the SUBEND command The SUB command assigns a name to the subprogram which you use to execute the subprogram at a later time Subprograms are stored in 3458A non volatile memory Subprograms downloaded into the 3458A can be executed later with a single command from the system controller or front panel keyboard This allows the system controller to perform other tasks while the 3458A is busy with other activities This provides multi tasking capability to your system controller because the 3458A is acting like a separate computer running tasks by itself Also commands within an 3458A subprogram execute faster than those same commands received over the GPIB because of the way the 3458A stores the subprogram commands internally What Commands Are Allowed Within a Subprogram Most commands for the 3458A may be stored and ex
492. ver by placing it into the slots of the instrument side castings Then push the cover toward the front of the instrument into the front panel bezel Refer to Figure 38 Turn the instrument so its back faces you Reinstall the rear bezel Use the TX15 Torx driver to reinstall the rear bezel screws Refer to Figure 37 Turn the instrument so its left side faces you Use the TX10 Torx driver to reinstall the top and bottom covers ground screws WARNING For safety purposes and proper operation it is very imperative that the cover grounding screws be reinstalled 8 9 Refer to Figure 36 Reinstall the left side handle strap Use the 1 pozidriv to reinstall side handle strap screws Refer to Figure 35 Turn the instrument so its right side faces you 10 Reinstall the right side handle strap Use the 1 pozidriv to reinstall side handle strap screws 11 Your instrument is now ready for use Keysight suggests that after you apply power that you perform an automatic calibration on the instrument To do this use the ACAL ALL command 318 Appendix C Procedure to Lock Out Front Rear Terminals and Guard Terminal Switches Appendix D Optimizing Throughout and Reading Rate Introducing the 3458A oo eccecseesetteeteeteeesees 321 Application Oriented Command Language 321 Intrinsically Slow Measurements 06 321 Maximizing the Testing Speed cc eee 322 Program Memory ccec
493. view the information If the ERR annunciator is illuminated at this point an error was detected during or after the power on self test You will learn how to determine the error later in this chapter in Reading the Error Register Operating from the Front Panel POWER SWITCH This section shows you how to make a simple DC voltage measurement how to use the various front panel keys and describes the multimeter functions important to front panel operation Figure 6 shows the multimeter s front panel features DISPLAY FRONT REAR TERMINALS SWITCH NUMERIC USER AND UTILITY KEYS FUNCTION RANGE SCROLL KEYS CONF IGURATION MENU KEYS FRONT INPUT TERMINALS GUARD SWITCH Figure 6 Front Panel Chapter 2 Getting Started 27 Making a In the power on state DC voltage measurements are selected and the Measurement multimeter automatically triggers and selects the range In the power on state you can make DC voltage measurements simply by connecting a DC voltage to the input terminals as shown in Figure 7 The connections shown in Figure 7 also apply for AC voltage 2 wire resistance AC DC voltage digitizing and frequency or period measurements from a voltage input source Refer to Chapter 3 fora CAUTION concerning the multimeter s maximum input voltage and current FOR GUARDED MEASUREMENTS ONLY ora ANI Term 1099Vpk Max N ISPC F 2 2 Figure 7 Standard
494. vm SWEEP 5E 6 200 5ys EFF INTERVAL 200 SAMPLES TRANSFER Dvm TO Samp WAIT TRANSFER SAMPLES TO CONTROLLER BUFFER FOR I 1 TO 200 IF ABS Samp I 1E 38 THEN DETECT OVERLOAD PRINT Overload Occurred PRINT OVERLOAD MESSAGE ELSE IF NO OVERLOAD OCCURRED Samp I DROUND Samp I 5 ROUND TO 5 DIGITS PRINT Samp I PRINT EACH SAMPLE END IF NEXT I END In the program on the following page the SSAC command is used to digitize a 10 kHz signal with a peak value of 5V The SWEEP command instructs the mu Itimeter to take 1000 samples Num_ samples variable with a 2us effective_interval Eff_int variable The measurement uses the default level triggering for the sync source event trigger from input signal 0 AC coupling positive slope Line 120 generates a SYN event and transfers the samples directly to the computer Lines 240 through 410 sort the sub sampled data to produce the composite waveform The composite waveform is stored in the Wave_form array 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_samples Inc 1I J K L DECLARE VARIABLES 30 Num_samples 1000 DESIGNATE NUMBER OF SAMPLES 40 Eff int 2 0E 6 DESIGNATE EFFECTIVE INTERVAL 50 INTEGER Int_samp 1 1000 BUFFER CREATE INTEGER BUFFER 60 70 80 90 00 01 05 10 T9 20 21 25 30 40 50 60 70 80 90 90 200 210 ALLOCATE REAL Wave_form 1 Num_samples CREATE ARRAY FOR SORTED DATA ALLOCATE REAL Samp 1 Num_samples
495. w Maximum Sec Reading 1 5 Hz 6 5 5 20 Hz 2 0 l 20 100 Hz 1 2 Resolution Maximum Sec Reading 100 500Hz 0 32 0 001 0 005 32 gt 500 Hz 0 02 0 005 0 01 6 5 0 01 0 05 3 2 Settling Characteristics a P ee There is no instrument settling required gt 1 01 Common Mode Rejection For 1 kQ imbalance in LO lead gt 90 dB DC to 60 Hz Resolution in is the value of RES command or parameter reading resolution as percentage of measurement range Additional error beyond 1 C but within 5 C of last ACAL of Range C For ACBAND gt 2 MHz use 10 mV range temperature coefficient Lo to Guard switch on Flatness error including instrument loading Reading time is the sum of the Sec Reading shown for your configuration The tables will yield the slowest reading rate for your configuration Actual reading rates may be faster For DELAY 1 ARANGE OFF Appendix A Specifications 289 High Frequency Temperature Coefficient Maximum Input For outside Tcal 5 C add the following error Rated Input Non Destructive of Reading C HI to LO 1000 Vpk 1200 V pk Frequency LO to Guard 200Vpk 350 V pk Range 2 4MHz 4 10MHz Guard to Earth 500 V pk 1000 V pk 10mV 1V 0 02 0 08 bes 1x10 1 Additional error beyond 10 V 1000 V_0 08 0 08 1 C but within 5 C of last A CAL Analog Mode ACV Function SETACV ANA 2 Specifications apply full vee Tempe
496. wer up state OUTPUT Dmm TRIG HOLD Stops triggering UTPUT Scan RESET UTPUT Scan CLOSE 200 400 410 STORE 1 UTPUT Scan CLOSE 308 309 STORE 2 UTPUT Scan OPEN 200 UTPUT Scan CLOSE 201 STORE 3 UTPUT Scan OPEN 201 UTPUT Scan CLOSE 206 STORE 4 UTPUT Scan OPEN 206 UTPUT Scan CLOSE 202 STORE 5 UTPUT Scan OPEN 202 UTPUT Scan CLOSE 205 STORE 6 UTPUT Scan OPEN 205 UTPUT Scan CLOSE 204 STORE 7 UTPUT Scan OPEN 204 UTPUT Scan CLOSE 203 STORE 8 OO OOO 0O OOOO O0 OOOO C0 80 bernas Channel list OUTPUT Scan SLIST 1 2 3 3 4 4 5 5 6 6 7 8 8 0 Setup the scan list for the states that are automatically incremented by the STEP command or the external 1 increment input signal OUTPUT Scan DMODE 1 1 0 1 Setup for external increment i and channel close on the scanner O UTPUT Dmm PRESET TARM HOLD Sets the dmm in its normal PRESET g and holds the trigger arm UTPUT Dmm MFORMAT DREAL Stores the data in memory in IEEE double real format UTPUT Dmm TRIG EXT Sets the dmm to trigger externally UTPUT Dmm APER 20E 6 Sets the integrator aperture to 20 us UTPUT Dmm TBUFF ON Sets up the trigger buffer does not occur UTPUT Dmm DISP OFF Turns off the front panel display on the 0 wO O O UTPUT DMM DELAY 0 Sets the time between trigger event and measurement start to 0 s OUTPUT Dmm SUB 1 Start of the dmm p
497. with your computer the 3458A can digitize wave forms with low distortion and very high resolution The 3458A has the measurement speed and precise timing necessary for direct sampling of signals with frequency components up to 50 kHz or with repetitive signals subsampling up to 12 MHz with 16 bits of resolution and more In this product note you will learn how to 1 Configure the 3458A to capture transient signals using direct sampling 2 Configure the 3458A to capture repetitive signals using sequential sampling 3 Use slope and level triggering to capture the data where you want 4 Transfer measured signal data from the 3458A to your HP 9000 Series 200 300 Computer at 100 kSamples s 5 Use the 3458A s Program Memory to capture signals on multiple channels store them in the 3458A s Reading Memory interrupt the HP 9000 Series 200 300 Computer when the task is complete and transfer the data from the multimeter to the computer for comparison analysis and graphic presentation 6 Use the 3458A Option 005 Wave Form Analysis Library to acquire analyze and present the digitized signals 7 Interpret specifications that pertain to wave form digitizing and dynamic performance Speed with Resolution e 16 bits 100 kSamples s 18 bits 50 kSamples s The 3458A offers you complete flexibility for speed and resolution over the audio frequency bandwidth The DCV measurement path can digitize your audio frequency signal w
498. without a controller State Storage permits a static instrument state to be totally defined and recalled from memory with a simple program command In addition the 3458A transfers high speed measurement data over GPIB or into and out its standard 10 000 or optional 75 000 Reading Memory at 100 000 readings per second Additional flexibility is provided by the 3458A s capability to perform data analysis internally to speed throughput and still give you the data you need for statistical quality control or for simple limit checking Program Memory can perform the pass fail math function and alert the computer to out of limits measurements with an interrupt flag Alternatively the many available math functions may be used to post process the data acquired in memory without loss of the maximum reading rate These include statistical functions mean standard deviation maximum minimum number of readings dB and dBm thermistor linearization RTD linearization scale filter functions and others The choice of whether to perform data analysis in the computer or in the dmm depends on the testing task and the convenience offered to the user by having these analysis functions available with a simple programming command Further gains in test throughput can be obtained by tailoring the measurement sequence to group similar measurements together thus minimizing the number of instrument configuration changes between measurements Custom programs writte
499. xcept STAT or PFAIL or when autorange is enabled Query Command The OFORMAT query command returns the present output format mode Refer to Query Commands near the front of this chapter for more information e Related Commands END ISCALE MFORMAT QFORMAT SINT Format The following program outputs 10 readings in SINT format retrieves the scale factor and multiplies the scale factor times each reading 10 OPTION BASE 1 COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_readings DECLARE VARIABLE 30 INTEGER Int_rdgs 1 10 BUFFER CREATE INTEGER BUFFER ARRAY 40 REAL Rdgs 1 10 CREATE REAL ARRAY 50 Num_readings 10 NUMBER OF READINGS 10 60 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 70 ASSIGN Int_rdgs TO BUFFER Int_rdgs ASSIGN BUFFER I O PATH NAME 80 OUTPUT Dvm PRESET NORM OFORMAT SINT NPLC 0 NRDGS Num_readings 85 TARM AUTO TRIG SYN SINT OUTPUT FORMAT MIN INTEGRATION TIME 90 TRANSFER Dvm TO Int_rdgs WAIT SYN EVENT TRANSFER READINGS INTO 91 INTEGER ARRAY SINCE THE COMPUTER S INTEGER FORMAT IS THE SAME AS 95 SINT NO DATA CONVERSION IS NECESSARY HERE INTEGER ARRAY REQUIRED 100 OUTPUT Dvm ISCALE QUERY SCALE FACTOR FOR SINT FORMAT 110 ENTER Dvm S ENTER SCALE FACTOR Chapter 6 Command Reference 211 OFORMAT 212 20 FOR I 1 TO Num_readings 30 Rdgs I Int_rdgs I CONVERT EACH INTEGER READING TO REAL 35 FORMAT NECESSARY TO PREVENT POSSIBLE INTEGER OVERFLOW ON NEX
500. y 108 Hold 29 Hold key 29 I ID 185 Implied read using 97 366 INDEX INBUF 185 Increasing the reading rate 102 Indication overload 96 99 Initial inspection 15 Input resistance fixed 62 terminals selecting the 50 Input buffer 75 Input complete 114 Input output statements 42 Inspection initial 15 Installation verification 21 Installing keyboard overlay 41 line power fuse 18 multimeter 17 Integer double 92 single 92 Integration time and resolution 104 directly specifying 60 setting the 59 67 Interrupts 77 ISCALE 187 L Language conventions 152 LEVEL 188 Level filtering 134 triggering 132 triggering examples 132 LFILTER 190 LFREQ 190 Limits line voltage 18 Line fuse caps 21 fuses power 21 power fuse installing the 18 power fuse replacing the 21 power requirements 17 voltage limits 18 voltage switches setting the 18 LINE 192 Local Key 44 LOCK 192 Long displays viewing 38 LSTN annunciator 27 M Maintenance 21 Manual ranging 30 autoranging and 29 MATH 27 193 annunciator 27 Math operations 116 enabling 116 Math registers 117 Maximum number of devices GPIB 20 MCOUNT 195 Measurement function changing the 28 specifying a 53 Measurements configuring for AC 62 configuring for DC or resistance 54 configuring for ratio 70 specifying ratio 71 triggering 81 Measuring temperature 125 MEM 196 Memory formats 95
501. y other format For the fastest transfer of high resolution readings 5 5 digits or greater made on a fixed range use the DINT format Whenever autorange is enabled and transfer speed is critical use the SREAL format for readings of 6 5 digits or less or the DREAL format for readings of 7 5 or 8 5 digits Disabling the display and any math operations will also ensure the fastest transfer from reading memory to the controller Chapter 4 Making Measurements 10 OPTION BASE 1 The following program is an example of transferring readings from reading memory to the controller at the fastest possible rate The program stores 5000 readings in reading memory using the SINT format The readings are removed from memory using the implied read and transferred to the controller in the SINT format using the TRANSFER statement line 130 The controller then retrieves the scale factor multiplies the scale factor times each reading and stores the corrected readings in the Rdgs array COMPUTER ARRAY NUMBERING STARTS AT 1 20 INTEGER Num_readings DECLARE VARIABLE 30 INTEGER Int_rdgs 1 30000 BUFFER CREATE INTEGER ARRAY FOR BUFFER 40 REAL Rdgs 1 30000 CREATE REAL ARRAY 50 Num_readings 30000 NUMBER OF READINGS 30000 60 ASSIGN Dvm TO 722 ASSIGN MULTIMETER ADDRESS 70 ASSIGN Int_rdgs TO BUFFER Int_rdgs ASSIGN BUFFER I O PATH NAME 80 OUTPUT Dvm PRESET FAST TARM SYN TRIG AUTO DCV 10V 90 OUTPUT Dvm APER 1 4E 6 1 4ys
502. y time Subprogram Delay time 1 48 s 500 510 520 530 540 550 730 740 750 760 770 780 790 800 810 820 SUB Delay REAL Dnld_time Exe time Tns_ time DIM A 37 Exe time TIMEDATE OUTPUT 722 PRESET OUTPUT 722 OHM 1E4 NPLC 0 DELAY 0 FOR I 1 TO 15 OUTPUT 722 ACV 10 ACBAND 5000 APER 20E 6 DELAY ENTER 722 A 34 OUTPUT 722 DCV 10 NPLC 0 DELAY 0 FOR I 35 TO 37 ENTER 722 A I NEXT I Exe time TIMEDATE Exe time Dn ld_time 0 Tns_time 0 SUBEND 01 The test situation is the same as the situation with correct integration time but now the delay time is set to a value that will produce measurements to the desired accuracy of each measurement instead of the default delays Using Reading memory Subprogram Burst test execution time 1 42 s reading transfer time 18 s 1830 1840 1850 1860 1870 1880 SUB Burst REAL Dnld_time Exe_time Tns_time DIM A 37 Exe_time TIMEDATE OUTPUT 722 PRESET MEM FIFO MFORMAT SREAL OUTPUT 722 OHM 1E4 NPLC 0 DELAY 0 NRDGS 15 TRIG SGL OUTPUT 722 OHM 1E5 NRDGS 8 TRIG SGL Appendix D Optimizing Throughout and Reading Rate 335 336 1940 OUTPUT 722 DCV 10 NPLC 0 DELAY O NRDGS 3 TRIG SGL 1950 Exe time TIMEDATE Exe time 1960 Dnld_time 0 1970 Tns_time TIMEDATE 1980 FOR I 1 TO 37 1990 ENTER 722 A TI 2000 NEXT I 2010 Tns_time TIMEDATE Tns_ time 2020 SUBEND A marked change is effected in the structure of the program Now the readings are stor
503. y utilizing a monolithic AC to DC converter Its accuracy while good is not as good as the synchronous ACV s its bandwidth while also good is not as good as the random or the synchronous ACV s But it does offer the ability to measure more accurately faster than either of the other methods over its measurement bandwidth And it can measure either repetitive wave forms or noise signals Synchronous ACV offers 1 Hz to 10 MHz bandwidth with excellent 100 ppm best accuracy but the input wave form must be repetitive The reading rate is determined by the frequency of the input wave form and the desired accuracy and resolution The technique is straightforward a frequency measurement is made on the input wave form the decision to sample the input sequentially or in bursts at 20 us intervals is made based on the value of the frequency and the measurements are processed statistically for the rms value The number of samples taken which is a measure of the speed is determined by the resolution selected and also determines the accuracy of the measurement Random ACV offers the same upper measurement bandwidth that synchronous ACV offers but the wave form can be noise or any non repetitive signal Since 328 Appendix D Optimizing Throughout and Reading Rate Comparison of ACV Modes the resolution of the measurement is dependent upon the number of samples this mode of operation is the least accurate and the slowest of the ACV functions for
504. ytes per reading DREAL a 8 bytes per reading ASCII This is the most commonly used output format because it has no scale factor and requires no special handling by the controller to convert the data Since ASCII uses the greatest number of bytes per reading use this format when measurement speed is not critical When using the ASCII format 2 additional bytes are required for the carriage return line feed cr If end of line sequence The er If is used only for the ASCII format and normally follows each reading output in ASCII format However when using the ASCII output format and multiple readings are recalled from reading memory using the RMEM command the multimeter places a comma between readings comma 1 byte In this case the er If occurs only once following the last reading in the group being recalled Commas are not used when readings are output directly to the bus reading memory disabled when readings are recalled using implied read or when using any other output format Single Integer SINT or Double Integer DINT Use the SINT format when making low resolution measurements 3 5 or 4 5 digits at the highest possible rate on a fixed range autorange disabled Since the SINT format is only 2 bytes per reading readings can be transferred across GPIB faster using SINT than any other format Use the DINT format when making high resolution measurements 5 5 digits or greater at the highest possible speed o

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