Contents
Agilent E1412A User’s Manual and SCPI Programming Guide
Edition 5
AgilentWarranty ........................................................................................................... 9
Safety Symbols ........................................................................................................... 10
WARNINGS ............................................................................................................... 10
Agilent E1412A Declaration of Conformity ..............................................................11
Chapter 1
Agilent E1412A Multimeter Module Setup ........................ ................... ........... .........15
Using T hi s Ch a p t er ... ....... .. .. .................................................................... .. .. ............... 15
General Information ............................................................................................ 15
Setting the Module Address Switch.. ........... ........... ...................... ................... ...........16
Interrupt Priority ......................................................................................................... 17
Setting the Line Frequency Reference........................................................................17
Checking the Line Frequency Reference ............................................................ 17
Multimeter Functiona l Connections ..................... .. ........... ........... ........... ............19
Initial O p e rat i o n . .. ..................... .. .. .......................................................................... ... . 22
Chapter 2
Agilent E1412A Multimeter Applicat ion Information ........................... ........... .......25
Using This Chapter ....................................................................................................25
Measurement Tutorial................................................................................................. 25
DC Volt a ge Measu remen ts.. .. ... ............................................................ ... .. ................. 25
Thermal EMF Errors ........................................................................................... 25
Loadi ng E rr o rs (d c vol t s ) ...... .. ... ...................................................... .. .. ............... 26
Leakage Current Errors ....................................................................................... 26
Rejecting Power Line Noise Voltages ................................................................ 27
Commo n Mo d e Reject i on ( C M R ) .. .. ................................................................... 27
Noise Caused by Magnetic Loops ....................................................................... 28
Noise Caused by Ground Loops .......................................................................... 28
Resistance Measurements ........................................................................................... 29
4-Wir e O h ms M e a s u rements ................................... .. .. ........................................ 29
Removing Field Wiring Resistance Errors in 2-Wire Ohms Measurements ......30
Power Dissipation Effects ................................................................................... 31
Settlin g T im e E ffects .. .. .. ............................................................. .. ... ................... 31
Errors in H igh R e si s t an c e Measur e m en t s ........................................................... 31
Making H ig h - S p e ed D C a n d Res i s tance Me a s u rements .................. .. .. ............... 31
DC Curr e n t Me as u remen t E rro r s.. .. ... ............................................................ ... .. ........ 3 2
True RM S A C Measu rements..... ............................................... .. ... ............................ 3 2
Crest Factor Errors (non- sinusoidal inputs) ............... ........... ................... ...........33
Loadi ng E rr o rs (a c vo lts ) ... ............. .. ... ................................................................ 34
AC Measurements Below Full Scale ..................................................................34
Function and Range Change Internal Offset Correction ..................................... 34
Low-L e v el Measur ement Errors ...................................................... .. .. ............... 35
AC Turnover Errors ............................................................................................35
AC Curr e n t Me as u remen t E rro r s.. .. ... ............................................................ ... .. ........ 3 6
Making H ig h - S p e ed A C V o lt age or Cur r e n t Mea s u rements... ................................... 36
Contents 1
Chapter 2
Agilent E1412A Multimeter Applicat ion Information (continued)
Frequency and Period Measurement Errors................................................................ 36
Measurement Configuration ....................................................................................... 37
AC Sign a l Fil t er .... ... .. ...................................................... .. .. ............................... 37
DC Input Resistance . ...........................................................................................37
Resolu tio n . .... ..... .... ... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... ... . 38
Integration Time .................................................................................................. 39
Autozero .............................................................................................................. 40
Ranging ............................................................................................................... 40
Math Operations (CALCulate Subsystem)................................................................. 41
AVERage Function ............................................................................................. 41
NULL (Relative) Function .................................................................................. 41
dB Mea su r ements ....... ............. ... .. ................................................................... ... . 42
dBm Measurements ............................................................................................. 43
LIMit F u n ct i on .... .. ... ............. .. ... ......................................................................... 44
Triggering the Multimeter .......................................................................................... 45
The Trigger Source .............................................................................................. 46
External Triggering ............................................................................................. 47
Intern al T r i ggering ......... .............. .. .. ................................................................... 47
Bus Triggering ..................................................................................................... 48
The Wait-for-Trigger State .................................................................................. 48
The Trigger Count ............................................................................................... 48
Checking the Trigger Count ................................................................................49
Inserting a Trigger Delay .................................................................................... 49
Defau lt D el a y s . .. ...................................................... .. .. ........................................ 50
Querying the Delay Time .................................................................................... 51
The Sample Count ............................................................................................... 51
Checking the Sample Count ................................................................................51
Agilent E1412A Multimeter Application Examples ..................................................52
Agilen t V T L Sof tw are (VISA) ..... .. .. ........................... ... .. ................................... 5 2
Example Programs .............................................................................................. 52
Making M u l t im et e r M ea s u remen ts ....... ...................................................... .. .. .... 53
Synchronizing the Multi meter With a Switch Module ......................... ........... ...57
Multimeter Status System Examples ...................................................................60
Agilent VEE Programming Example .................................................................. 64
2 Contents
Chapter 3
Multim eter Co m m a n d Referen c e . .. ....... .. ... ................................................................ 6 7
Using T hi s Ch a p t er ... ....... .. .. .................................................................... .. .. ............... 67
Command Types ......................................................................................................... 67
Commo n Co mman d Fo rmat .. .. ... ...... ... .. .............................................................. 6 7
SCPI Co m mand F or mat ...... ............. ... .. .............................................................. 67
Linking Commands ............................................................................................. 69
Multimeter Range and Resolution Ta bles ..................................... ........... ........... .......70
SCPI Co m mand R eference ........................................................ .. ... ............................ 7 1
ABORt ........................................................................................................................72
Chapter 3
Multime ter Co m ma nd Re fer e nc e (continued)
CALCulate .................................................................................................................. 73
:AVERage:AVERage? ........................................................................................ 74
:AVERage:COUNt? ............................................................................................ 74
:AVE Rage:MAX imum? . ............ ........... ........... ......... ........... ............ ........... ........ 74
:AVERage:MINimum? ....................................................................................... 74
:DB:REFerence ................................................................................................... 75
:DB:RE Fere n ce? .... ... .. ............................................... .. ... ..................................... 75
:DBM :REFere nce ..... ...... ......... ......... ......... ....... ......... ......... ......... ....... ......... ........ 7 5
:DBM:REFerence? .............................................................................................. 75
:FUNC tion .... ............ ........... ........... ......... ........... ............ ......... ........... ........... ...... 76
:FUNCtion? ......................................................................................................... 76
:LIMit:LOWer ..................................................................................................... 77
:LIMit:LOWer? ................................................................................................... 77
:LIMit:UPPer .......................................................................................................77
:LIMit:UPPer? ..................................................................................................... 77
:NUL L:OF FS et .. .. ..... .... ..... .. .... ..... .. ..... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... . 78
:NUL L:OFFS et? ....... ...... ......... ......... ....... ......... ......... ......... ....... ......... ......... ........ 7 8
:STATe ................................................................................................................ 78
:STATe? .............................................................................................................. 78
CALibration................................................................................................................ 79
:COUNt? ..............................................................................................................79
:LFRequency ....................................................................................................... 79
:LFRequency? ..................................................................................................... 80
:SECure:CODE ................................................................................................... 80
:SECure:STATe .................................................................................................. 81
:SECur e:ST ATe? ... ....... ....... ....... .... ....... ....... ...... ..... ....... ...... ....... ..... ...... ....... ...... 81
:STRing ............................................................................................................... 81
:STRin g? . .. .... ..... .... ... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... ... . 82
:VAL ue ....... ......... ....... ......... ......... ......... ....... ......... ......... ......... ...... ......... ......... .... 82
:VALue? .............................................................................................................. 82
:ZERO:AUTO ..................................................................................................... 83
:ZERO:AUTO? ................................................................................................... 83
CALibration? .............................................................................................................. 84
CONFigure.................................................................................................................. 85
:CURRent:AC ..................................................................................................... 87
:CUR Rent[: DC] . .... ....... ....... .... ....... ....... ....... .... ....... ....... ...... ..... ....... ...... ....... ..... .8 8
:FREQuency ........................................................................................................ 89
:FRESistance ....................................................................................................... 90
:PERiod ............................................................................................................... 91
:RESistance ......................................................................................................... 92
:VOL Tage:AC ... ............. .............. ............................................. ............. ............. 93
[:VOL Tag e[ :DC ]] .. ..... .... ..... .. ..... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... . 94
[:VOLTage[:DC]] :RATio ................................................................................... 95
CONFigure?................................................................................................................ 96
DATA ......................................................................................................................... 97
:POINts? .............................................................................................................. 97
Contents 3
Chapter 3
Multime ter Co m ma nd Re fer e nc e (continued)
FETCh?....................................................................................................................... 98
INITiate....................................................................................................................... 99
[:IMMediate] ....................................................................................................... 99
INPut......................................................................................................................... 100
:IMPedance:AUTO ........................................................................................... 100
:IMPed an ce: AU TO ? ... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... ... .... ..... .... .. .. 100
MEASure .................................................................................................................. 101
:CUR Rent :A C? .. .. ..... .... ..... .. .... ..... .. ..... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. .... 102
:CUR Rent[:DC]? . ........... .............. ............. .................................................... .... 103
:FREQuency? .................................................................................................... 104
:FRESistance? ................................................................................................... 105
:PERio d? . .. .... ..... .... ... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... .. 106
:RESis tan ce ? . ..... .... ..... .. ..... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... .. 107
:VOLTage:AC? ................................................................................................. 108
[:VOL Tage[ :DC]]? ... ...... ......... ......... ......... ....... ......... ......... ......... ....... ......... ...... 10 9
[:VOL Tag e[ :DC ]]:R A Tio? .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... .. 110
OUTPut..................................................................................................................... 111
:TTLTrg[:STATe] .............................................................................................111
:TTLTrg[:STATe]? ...........................................................................................112
READ?......................................................................................................................113
SAMPle..................................................................................................................... 114
:COUNt .............................................................................................................114
:COUNt? ............................................................................................................115
[SENSe:] ................................................................................................................... 116
FUNCtion .......................................................................................................... 118
FUNCtion? ........................................................................................................ 118
CURRent:AC:RANGe ......................................................................................119
CURRent:AC:RANGe? ....................................................................................119
CURRent:AC:RANGe:AUTO .......................................................................... 120
CURRent:AC:RANGe:AUTO? ........................................................................120
CURRe nt:A C:RE Solu tion . ...... ....... ..... ...... ....... ....... .... ....... ....... .... ....... ....... ...... 12 1
CURRe nt:AC:RESolut ion? ........ ............. .............. ............................................ 121
CURRent[:DC]:APERture ................................................................................ 122
CURRent[:DC]:APERture? .............................................................................. 122
CURRent[:DC]:NPLC ...................................................................................... 123
CURRe nt[:D C]:N PLC ? ....... .... ....... ....... ....... .... ....... ....... ...... ..... ....... ...... ....... .... 12 3
CURRe nt[ :DC ]: RAN G e .... .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... .. 124
CURRe nt[:DC]: RANGe? ........... ........... ........... ......... ........... ............ ........... ...... 124
CURRent[:DC]:RANGe:AUTO ....................................................................... 125
CURRe nt[ :DC ]: RAN G e:A UT O? . .... ..... .. ..... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... .. 125
CURRe nt[:DC]:RE Solution ............. .............. ........... .............. ............. ............. 1 26
CURRent[:DC]:RESolution? ............................................................................ 126
DETector:BANDwidth ......................................................................................127
DETector:BANDwidth? .................................................................................... 128
FREQ uen cy: APE Rt ure ... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... ... .... .... 128
FREQ uency:APE Rture? . ............ ......... ........... ........... ........... ......... ............ ........ 128
4 Contents
Chapter 3
Multime ter Co m ma nd Re fer e nc e (continued)
[SENSe:] (continued)
FREQuency:VOLTage:RANGe ........................................................................129
FREQ uency:VO LTage:R ANGe? ... ........... ......... ............ ........... ........... ......... .... 1 29
FREQuency:VOLTage:RANGe:AUTO ...........................................................130
FREQuency:VOLTage:RANGe:AUTO? ..........................................................130
FRESi stan ce:AP ERtu re ..... ...... ....... ..... ...... ....... ....... .... ....... ....... ....... .... ....... ...... 1 31
FRESi stance:A PERture? ......... ............ ........... ......... ........... ........... ............ ........ 13 1
FRESi stance:NP LC ........... ............. ........... .............. ............. ............................. 132
FRESistance:NPLC? ......................................................................................... 132
FRESistance:RANGe ........................................................................................ 133
FRESistance:RANGe? ...................................................................................... 133
FRESistance:RANGe:AUTO ............................................................................ 134
FRESistance:RANGe:AUTO? .......................................................................... 134
FRESistance:RESolution .................................................................................. 135
FRESi stan ce:RE Solu tion? . .... ....... ....... ...... ..... ....... ...... ..... ....... ...... ....... ..... ...... .. 1 35
PERiod :APERture ...... ............. ............ ............. .............. ................................... 136
PERiod:APERture? ........................................................................................... 136
PERiod:VOLTage:RANGe ............................................................................... 137
PERiod:VOLTage:RANGe? ............................................................................. 137
PERiod:VOLTage:RANGe:AUTO ...................................................................138
PERiod:VOLTage:RANGe:AUTO? ................................................................. 138
RESist ance:AP ERture .. ........... ......... ............ ........... ........... ......... ........... ........... 1 39
RESistance:APERture? ..................................................................................... 139
RESistance:NPLC ............................................................................................. 140
RESistance:NPLC? ........................................................................................... 140
RESistance:RANGe ..........................................................................................141
RESistance:RANGe? ........................................................................................141
RESistance:RANGe:AUTO .............................................................................. 142
RESistance:RANGe:AUTO? ............................................................................ 142
RESist anc e:RES oluti on ..... ...... ....... ..... ...... ....... ..... ...... ....... ....... .... ....... ....... ...... 1 43
RESist ance:RE Solution? ......... ............ ......... ........... ........... ........... ......... ........... 14 3
VOLTage:AC:RANGe ...................................................................................... 144
VOLTage:AC:RANGe? .................................................................................... 144
VOLTage:AC:RANGe:AUTO ..........................................................................145
VOLTage:AC:RANGe:AUTO? ........................................................................ 145
VOLTage:AC:RESolution ................................................................................ 146
VOLTage:AC:RESolution? .............................................................................. 146
VOLT age[:DC] :APERtu re ......... ........... ........... ......... ........... ............ ........... ...... 147
VOLTage[:DC]:APERture? .............................................................................. 147
VOLTage[:DC]:NPLC ...................................................................................... 148
VOLTage[:DC]:NPLC? .................................................................................... 148
VOLTage[:DC]:RANGe ................................................................................... 149
VOLTage[:DC]:RANGe? ................................................................................. 149
VOLT age[:DC]:RANG e:AUTO .... .............. .................. ............. .............. ........ 1 50
VOLTage[:DC]:RANGe:AUTO? ..................................................................... 150
VOLT ag e [ :D C]:RESolut i o n .. .. ............................................................. .. ... ........ 1 5 1
Contents 5
Chapter 3
Multime ter Co m ma nd Re fer e nc e (continued)
[SENSe:] (continued)
VOLT age[:DC ]:RES olutio n? ....... ......... ......... ....... ......... ......... ......... ...... ......... .. 1 51
ZERO:AUTO .................................................................................................... 152
ZERO:AUTO? .................................................................................................. 152
STATus..................................................................................................................... 153
:PRESet ............................................................................................................. 153
:QUEStionable:CONDition? ............................................................................. 153
:QUE Stion a ble :ENA B le . ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... ... .... .... 153
:QUE Stionable :ENABl e? ........... ......... ........... ........... ........... ......... ............ ........ 154
:QUEStionable[:EVENt]? ................................................................................. 154
SYSTem....................................................................................................................155
:ERR or? .... ............. ............ ............. .............. ................................................... .. 155
:VERS ion? .. ....... .... ....... ....... .... ....... ....... ....... .... ....... ....... ...... ..... ....... ...... ....... .... 15 5
TRIGger .................................................................................................................... 156
:COUNt .............................................................................................................156
:COUNt? ............................................................................................................157
:DELay .............................................................................................................. 157
:DELay? ............................................................................................................ 158
:DELay:AUTO .................................................................................................. 158
:DELay:AUTO? ................................................................................................ 159
:SOUR ce . .. .... ..... .... ... .... ..... .... .. ..... .... ..... .. ..... .... ..... .. .... ..... .... ... .... ..... .... .. ..... .... .. 160
:SOUR ce? . ......... ......... ......... ....... ......... ......... ......... ...... ......... ......... ......... ....... .... 1 61
IEEE 488.2 Common Command Quick Reference . .................................................162
*CLS .. .. .............. .. .. ........................................................................... .. .. ............. 16 3
*ESE an d *E SE ? . .. ... .................... .. .. ................................................................. 1 6 3
*ESR ? ......... ......... ....... ......... ......... ....... ......... ......... ......... ...... ......... ......... ......... .. 164
*IDN? ................................................................................................................ 164
*OPC ................................................................................................................. 164
*OPC? ............................................................................................................... 165
*RST .. .. .............. .. .. ........................................................................... .. .. ............. 16 5
*SRE and *SRE? ............................................................................................... 165
*STB ? ......... ......... ....... ......... ......... ....... ......... ......... ......... ...... ......... ......... ......... .. 166
*TST? ................................................................................................................ 166
*WAI . ........................................................... ............. .............. .......................... 166
SCPI Command Quick Reference ............................................................................ 167
6 Contents
Appendix A
Agilent E1412A Multimeter Specific ations .................... ........... ........... ...................171
DC Cha ra ct eristi cs .. .. ...................................................... .. .. ...................................... 1 7 1
AC Cha ra ct eristi cs .. .. ...................................................... .. .. ...................................... 1 7 4
Frequency and Period Characteristics.......................................................................177
General Specifications.............................................................................................. 179
To Calculate Total Measurement Error .................................................................... 180
Interpreting Multimeter Specifications ..................................................................... 182
Config u r i n g for H i g h A ccuracy Measur ements..... ................................................... 184
Appendix B
Agilent E1412A Multimeter Error Message s ............... .................... ........... ........... .185
Execu t i o n Er ro rs ......... .................... ... .. ..................................................................... 1 8 5
Self-Test Errors ................................................................................................. 189
Calibration Errors .............................................................................................. 190
Appendix C
Measurement Speed and Accuracy Trade-offs ....................................................... 193
Agilent E1412A Special Function and Range Commands (Non-SCPI )..................193
Speed Advantage Using the Special Non- SCPI Commands
(F1-F4 and R1-R7) ...................................................................................... 194
Agilent E1412A Resolution Using Spec ial Functions and Ranges.......... ........... .....195
Resolu t io n E xa m p l e .............................................. .. .. ........................................ 195
Gener a l Gui d e l ines for In creasin g Measu rement S p eed. ........................................ .. 196
Avoid F u n ct i o n Ch anges ....... .................... ... .. ................................................... 196
Avoid A p e rt u r e Ch anges ..... ................................................................... ... .. ...... 19 6
Minimize the Number of Command/
Response Sessions .............................................................................................196
Set Auto zero to O N C E o r OF F .. .. .. ................................................................... 197
Turn Autorange OFF ......................................................................................... 197
Decrease Aperture Time or NPLCs .................................................................. 197
Store the Readings in Multimeter RAM Instead of Sending the m Directly
to the Co mpute r .. .......................................................................... .. .. ........... 1 9 8
Index ..............................................................................................................................199
Contents 7
Notes:
8 Contents
Certification
Agilent Technologie s, Inc. certifies that this product met its published specifications at the time of shipment from the factor y. Agilent
Technol ogies furthe r certifie s that its calibration measurements ar e traceable to the United States National Institute of Standards and
Technology (formerly National Bureau of Standards), to the extent allowed by that organization's calibration facility, and to the
calibration facilities of other Internati onal Standards Organization members.
AGILENT TECHNOLOGIES WARRANTY STATEMENT
PRODUCT: E1412A DURATION OF WARRANTY: 1 year
1. Agilent warrants Agilen t hardware, accessories and supplies against defects in materials and workmanship for the period specified
above. If Ag lent receives notice of such defects during the warranty period, Agilent will, at its option, ei ther repair or replace products
which prov e to be defecti ve. Replacement products may be either new or like-new.
2. Agile nt warrants that Agilent software will not fail to execute its programming instructions, for the period specified above, due to
defect s in material and workmans hip when properly instal led and used. If Agilent receives notice of such defects during the warranty
period , Ag ilent will replace software media w hich does not execute its programming i nstructions due to such defects.
3. Agile nt does not warran t that th e opera tion of A gilent pr oducts w ill be i nterrup ted or e rror fre e. If Agi lent is unable , with in a rea sonabl e
time, to rep ai r or repla ce an y pro duct to a cond iti on as warr anted , cu st omer will be en ti tled to a r efund of the purc hase pr ic e upo n prompt
return of the product.
4. Agilen t products may contain remanufactur ed parts equivalent to ne w in performance or may have bee n subject to inc idental use.
5. The war ranty per iod be gin s on the dat e of de li very o r on the dat e of inst al lati on if ins tall ed by Agile nt . If c ust omer sc hedule s or de la ys
Agilent installation more tha n 30 days after delivery, wa rranty begins on the 31st day from delive ry.
6. Warran ty does not apply t o defec ts resul ting fr om (a) imp roper or inad equate ma intenan ce or ca librat ion, (b) s oftwar e, inte rfacing, pa rts
or suppl ies not suppli ed by Agilent Technologies , (c) unauthorized modification or m isuse, (d) operation outside of the published
enviro nm ental specifications for the produ ct, or (e) impr oper site preparatio n or m aintenance.
7. TO THE EXTENT ALLOWED BY LOCAL LAW, THE ABOVE WARRANTIES ARE EXCLUSIVE AND NO OTHER
WARRANTY OR CONDITION, WHETHER WRITTEN OR ORAL, IS EXPRESSED OR IMPLIED AND AGILENT
SPECIFICALLY DISCLAIMS ANY IMPLIED WARRANTY OR CONDITIONS OF MERCHANTABILITY, SATISFACTORY
QUALITY, AND FITNESS FOR A PARTICULAR PURPOSE.
8. Agil ent will b e liabl e for da mage to tangibl e prope rty per i ncident u p to th e grea ter of $30 0,000 o r the act ual amou nt paid for t he pro duct
that is the subject of the claim, and for damages for bodily injury or death , to the extent that all such damages are determine d by a court
of competent jurisdiction to hav e been directly caused by a defective Agi lent product.
9. TO THE EXTENT ALLOWED BY LOCAL LAW, THE REMEDIES IN THIS WARRANTY STATEMENT ARE CUSTOMER’S
SOLE AND EXLUSIVE REMEDIES. EXCEPT AS INDICATED ABOVE, IN NO EVENT WILL AGILENT OR ITS SUPPLIERS BE
LIABLE FOR LOSS OF DATA OR FOR DIRECT, SPE CIAL, I NCIDENTAL, CONSEQUE NTIAL (INCL UDING LOST PROFI T OR
DATA), OR OTHER DAMAGE, WHETHER BASED IN CONTRACT, TORT, OR OTHERWISE.
FOR CONSUMER TRANSACTIONS IN AUS TRALIA AND NEW ZEALAND: THE WARRANTY T ERMS CONTAINED I N THIS
STATEMENT, EXCEPT TO THE EXTENT LAWFULLY PERMITTED, DO NOT EXCLUDE, RESTRICT OR MODIFY AND ARE
IN ADDITION TO THE MANDATORY STATUTORY RIGHTS APPLICABLE TO THE SALE OF THIS PRODUCT TO YOU.
U.S. Government Restricted Rights
The Software and Docume ntation have been developed entirely at private expense. They are del ivered and licensed as "commercial
computer software" as defined in DF A RS 252.227- 7013 (Oct 1988), DFARS 252.211-7015 ( May 1991) or DFAR S 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)(o r any equivalent agency regulation o r contract clause), whichever is appl icable. You have only those rights provided for such
Software and Documentation by the applicable FAR or DFARS cl ause or the Agilent standard sof tw are agreement for the product
involved.
This is a mea surement Category II product designed for measur em ents at volta ges up to 300V from earth, including measurements of
voltages at typical mains socket outlets. The product should not be used to make voltage measurements on a fixed electrical installation
includ ing building wiring, ci rcuit breakers, or service panels.
IEC Measurement Category II Overvoltage Protection
E1412A 6½-Digit Multimeter User's Manual
Edition 5
Copyrig ht © 1998-2006 Agilent Technologies, Inc. All Rights Rese rved.
9
Documentation History
All Ed ition s and Upd ates of this manual and their creation date are listed be low. The first Edit ion of the ma n u al is Edition 1. The Edition
number increments by 1 whenever the manual is revised. Updates, which ar e issued between Editions, contain replacemen t pages to
correc t or add additional information to the cu rrent Editi on of the manual. Whenever a new Ed ition is created, it will contain all of the
Update in formatio n for the previous Edi tion. Eac h new Editi on or Update al so incl udes a revi sed copy of this docum entati on histor y page.
Edition 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .August 1995 Edition 5 . . . . . . . . . . . . . . . . . . . . . . . February 1998
Edition 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . January 1996 Edition 5 Rev 2 . . . . . . . . . . . . . . . . . . February 2006
Edition 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .June 1996
Edition 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . October 1997
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Windows NT® is a U.S. regist ered trademark of Microsoft Corporation
Windows® and MS Windows® are U.S. registered tradem arks of Micro soft Corporat ion
Safety Symbols
Instruction manual symbol affixed to
Instruction manual symbol affixed to
product . Ind ica te s t hat t he u ser must r efer t o
product . Ind ica te s t hat t he u ser must r efer t o
the manu a l fo r sp ec ific WAR N IN G or
the manu a l fo r sp ec ific WAR N IN G or
CAUTION information to avoid personal
CAUTION information to avoid personal
injury or dam age to the product.
injury or dam age to the product.
Indicates the field wiring terminal that must
be connect ed to earth ground befo re
operating the equipment—protects against
electrical shock in case of fault.
WARNING
Alternating current (AC)
Direct current (DC).
Indicates hazardous voltages .
Calls attention to a procedure, pra ctice, or
condition that could cause bodily injury or
death.
or
Frame or c hassis grou nd termina l—typicall y
connect s to the equipment's metal frame.
CAUTION
Calls attention to a procedure, pra ctice, or
condition that could po ssibly c ause damage to
equipment or permanent loss of data.
WARNINGS
The follo w ing general safety precautions mus t be observed during all phases of operation, se rvice, 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. Agil ent Technologies, Inc. assumes no liability for the cus tomer's failure to comply wi th these requirements.
Ground the equipm ent: For Safety Class 1 equipment (equipment having a protective earth terminal), an uninterruptible safety earth
ground must be provided from the mains pow er source to th e product input wiring term inals or supplied power ca ble.
DO NOT operate the produc t in an explosive atmosphere or in the pr esence of flam m able gases or fumes.
For cont inued protection a gainst fir e, replace the line fuse(s) only with fuse(s) of the same voltage and current rating a nd type. DO NOT
use repaired fuse s or short-circuited fuse holder s.
Keep away from live circuits: Operating personnel must not remove equipment covers or shield s. Procedures involving the removal of
covers or shields are f or use by service-trained personnel only. Unde r certain conditions , dangerous voltages may exist even with the
equipmen t sw itch ed off. To a void d ang er ous elect r ical sho ck, DO NOT per form proc edu re s invo lv ing co ver or shie ld rem oval u nl ess 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 been
impaired, either t hrough physical damage, excessive mo isture, or any other reason, REMOVE POWER an d do not use the product unti l
safe operat i on ca n be veri fi ed by servi ce- trai ne d person nel . If ne ces sa ry, re tu rn the pr odu ct to an Agi lent Tech nologi es Sales and Servi ce
Office for service and rep air to ensu re that safety feat ures are mai n tained.
DO NOT serv ice or adj ust al one : Do not at t empt in te rnal ser vi ce or adj us tmen t u nl ess an oth er per son , cap abl e o f rend er in g fi rst ai d an d
resuscitation, is present.
DO NOT substitut e parts or modify e quipm ent: Be cause of the da nger of intr od ucing a ddi tion al hazar ds, do not in st all s ubsti t ute pa rt s
or perform any unauthorized modification to the product. Retu rn the product to an Agilent Technologie s Sales and Service Office for
service and repair to ensure that safety features are maintained.
10
According to ISO/IEC Guide 22 and CEN/CENELEC EN 45014
11
DECLARATION OF CONFORMITY
Manufacturer’s Name:
Manufacturer’s Address:
Agilent Technologies, Incorporated
815 – 14
th
St. SW
Loveland, CO 80537
USA
Declares under sole responsibility that the product as originally delivered
Product Name:
Model Number:
Product Options:
VXI Multimeter Module
E1412A
This declaration covers all options of the above product(s)
complies with the essential requirements of the following applicable European Directives, and
carries the CE marking accordingly:
Low Voltage Directive (73/23/EEC, amended by 93/68/EEC)
EMC Directive (89/336/EEC, amended by 93/68/EEC)
and conforms with the following product standards:
EMC Standard
IEC 61326-1:1997+A1:1998 / EN 61326-1:1997+A1:1998
CISPR 11:1990 / EN 55011:1991
IEC 61000-4-2:1995+A1:1998 / EN 61000-4-2:1995
IEC 61000-4-3:1995 / EN 61000-4-3:1995
IEC 61000-4-4:1995 / EN 61000-4-4:1995
IEC 61000-4-5:1995 / EN 61000-4-5:1995
IEC 61000-4-6:1996 / EN 61000-4-6:1996
IEC 61000-4-11:1994 / EN 61000-4-11:1994
Canada: ICES-001:1998
Australia/New Zealand: AS/NZS 2064.1
Safety
The product was tested in a typical configuration with Agilent Technologies test systems.
IEC 61010-1:2001 / EN 61010-1:2001
Canada: CSA C22.2 No. 61010-1:2004
UL 61010-1: 2004
Limit
Group 1 Class A
4 kV CD, 8 kV AD
3 V/m, 80-1000 MHz
0.5 kV signal lines, 1 kV power lines
0.5 kV line-line, 1 kV line-ground
3 V, 0.15-80 MHz 1 cycle, 100%
1 cycle, 100%
Supplementary Information:
This DoC applies to above-listed products placed on the EU market after:
4 January 2006
Date
For further information, please contact your local Agilent Technologies sales office, agent or distributor,
or Agilent Technologies Deutschland GmbH, Herrenberger Straße 130, D 71034 Böblingen, Germany.
Ray Corson
Product Regulations Manager
Template: A5971-5302-2, Rev. B.00 E1412A-DoC-B DoC Revision B
Notes:
12
Notes:
13
Notes:
14
Using This Chapter
Chapter 1
Agilent E1412A Multimeter
Module Setup
This chapter p rovides one page of general module info rmation followed by
the tasks you must perform to set up your module and verify your
installation was successful. Chapter contents are:
• Setting the Module Address Switch
• Interrupt Priority
• Setting and Checking the Line Frequency Reference
• Input Terminals and Front Panel Indicators
• Multimeter Functional Connections
• Initial Operation
General Informati on • The E1412A (VXI C-size) Multimeter is a VXIbus message-based
slave device.
• Programming the multimeter can either be through a command module
using an GPIB interface or an embedded controller. You use the
Standard Commands for Prog rammable Instruments (SCPI; see
Chapter 3) with the St andard Instrument Cont rol Language (SICL) or
VISA (Virtual Instrument Software Architecture).
• Maximum voltage is 300 V
• Maximum cu rrent is 3A AC
or 300 Vdc.
rms
or DC.
rms
• Resolution is from 4½-digits for fast measurements to 6 ½- digits for
more accuracy. Resolution is set by specifying the integration time in
number of power line cycles (NPLCs) or corresponding apertur e time.
Table 1-1 shows the correlation between NPLCs and resolution.
Table 1-1. Resolution of Power Line Cycles
Power Line Cycles Resolution
0.02 0.0001 x Full- Scale
0.2 0.00001 x Full-Scale
1 0.000003 x Full- Scale
10 0.000001 x Full- Scale
100 0.0000003 x Full-Scale
Chapter 1
Agilent E1412A Multimeter Module Setup 15
Setting the Module Address Switch
The logical address switch f actor y setting is 24. Valid addresses are from
1 to 254 for static configurat ion (the address you set on the switch) and
address 255 for dynamic configuration. The E1412A supports dynamic
configuration of the a ddress. Thi s means th e address is set progra mmatically
by the resource manager when it encount ers a m odule with address 25 5 that
supports dynamic config uration.
If you install m ore than one multimeter, eac h module must have a differe nt
logical address. If you use a VXIbus command module, the logic al address
must be a multiple of eight ( e.g., 32, 40, 48, etc.) Each instr ument must have
a unique secondary address which is the logical address divided by eight.
Note When using an E1405A/B or E1406A as the VXIbus resource manager
with SCPI com mands, the mul tim eter's address swit ch va lue mu st be a
multiple of 8.
16 Agilent E1412A Multimeter Module Setup
Figure 1-1. Setting the Logical Address
Chapter 1
Interrupt Priority
The E1412A Multimeter is a VXIbus interrupter. However, there is no
interrupt priority level setting to be made on the module. Interrupt priority
level, setup, and activa tion are configured on the resour ce manager which is
the interface to the VXIbus and contains any instrument drivers required to
communicate with a VXI module. Your resource manager could be a VXI
command module, embedded P C controller, th e PC-based VXLink Interf ace
(ISA-to-VXI), t he Series 700 wor kstation VXI- MXIbus interface or another
VXI controller. To configure the interrupt priority on the E1405B and
E1406A Command Modules, you would use the
command subsystem. Refer to your resource manager's documentation for
information on setting the system's interrupt priority.
Setting the Line Frequency Reference
You must set the line frequency ref erence to the line frequency of the power
source to your mainframe for maximum normal mode rejection (NMR).
NMR is the multimeter 's ability to r eject power lin e frequency noi se in a DC
voltage or ohms measurement. You should set the multimeter's line
frequency referenc e to the exac t power line frequency (50, 60 or 400Hz).
Failure to set the line frequency reference to that of your source will cause
reading errors .
DIAGnostic:INTerrupt
Checking the Line
Frequency
Reference
You use the
reference. The default setting at power-on is 60Hz. If you use 50Hz or
400Hz you need to set the line frequency reference for maximum NMR.
Specifying 400Hz actually sets the line frequency reference to 50Hz since
50Hz is a sub harmonic of 400Hz. Executing a
will return +50 after executing
reference to 400Hz.
The line frequency refer ence setting is also useful when the device being
measured operates at a different frequency than the multimeter. For
example, if the mul timeter has a power li ne frequency referenc e of 60Hz and
the device being measured has a power line frequency of 50Hz, maximum
NMR is achieved by setting the multimeter's reference frequency to 50Hz
by executing:
The CALibration:LFRequency? command returns the present setting of the
power line frequency reference. The command returns +50 or +60. For a
setting of 400Hz, +50 is returned since 50Hz is a sub harmonic of 400Hz.
CALibration:LFRequency comm an d to se t the lin e freq uen c y
CALibration:LFRequency ?
CAL:LFR 400 to set the line frequency
CAL:LFR 50
Chapter 1
Agilent E1412A Multimeter Module Setup 17
Figure 1-2. Multimeter Measuremen t Terminals
18 Agilent E1412A Multimeter Module Setup
Chapter 1
Multimeter Functional Connections
WARNING - Shock Hazard. Do not use
unshrouded (bare) banana plugs as shown for
volta ges over 30 Vrm s or 60 VDC. For higher
voltages, use probe assemblies rated for the
appropriate voltage and equipped wit h shrouded
banana plugs.
Figure 1-3 . S witch Modu le Analog Bus C on ne ctions
Chapter 1
Figure 1-4. Frequency or Period Measu rem en t Conne ctions
Agilent E1412A Multimeter Module Setup 19
Figure 1-5. Voltage Measurement Connections
Figure 1-6. Voltage Ratio (Vdc) Measurement Connections
20 Agilent E1412A Multimeter Module Setup
Chapter 1
Figure 1-7. 2-Wire Ohms Measurement Connections
Chapter 1
Figure 1-8. 4-Wire Ohms Measurement Connections
Agilent E1412A Multimeter Module Setup 21
Initial Operation
Note This discussion applies only to SCPI (Standard Commands for
Figure 1-9. Current Measurement Connections
To program the Multimeter using SCPI, you must select the interface
address and SCPI commands to be used. General information about using
SCPI commands is presented at the beginning of Chapter 3. See the 75000
Series C Installation and Getting Started Guide for interface addressing.
Programmable Instruments) programming. The program is written using
VISA (Virtual Instrument Software Architecture) function calls. VISA
allows you to execute on VXIplug&play system frameworks that have the
VISA I/O layer installed (visa .h include file).
Programming the
Multimeter
22 Agilent E1412A Multimeter Module Setup
Exampl e: Perform a Sel f-Test of the M u lt im eter and R ead the
Result.
Programming the mul timeter us ing S tandar d Commands for Progr ammable
Instruments (SCPI) requires that you select the controller language (e.g., C ,
C++, Basic, etc.), interface address and SCPI commands to be used. See the
75000 Series C Installati on and Getting Started Guide (or equivalent) for
interfacing, addressing and controller infor mation.
The following C program verifies c ommunication between the controller,
mainframe and multim eter. It re sets the m odule (
of the module (
*RST), queries the identi ty
*IDN?) and initiates a self-test of the multimeter.
Chapter 1
#include <stdio.h>
#include <visa.h>
/*** FUNCTION PROTOTYPE ***/
void err_handler (ViSession vi, ViStatus x);
void main(void)
{
char buf[512] = {0};
#if defined(_BORLANDC_) && !defined(_WIN32_)
_InitEasyWin();
#endif
ViStatus err;
ViSession defaultRM;
ViSession dmm;
/* Open resource manager and multimeter sessions. */
viOpenDefaultRM (&defaultRM);
viOpen(defaultRM, "GPIB-VXI0::9::24", VI_NULL, VI_NULL, &dmm);
/* Set the timeout value to 10 seconds. */
viSetAttribute (dmm, VI_ATTR_TMO_VALUE, 10000);
/* Reset the module. */
err = viPrintf (dmm, "*RST/n");
if (err<VI_SUCCESS) err_handler (dmm, err);
/* Query the module id entification . */
err = viPrintf(dmm, "*IDN?/n");
if (err<VI_SUCCESS) err_handler (dmm, err);
err = viScanf(dmm, "%t", buf);
if (err<VI_SUCCESS) err_handler (dmm, err);
printf ("Module ID = %s/n/n", buf);
/* Perform a module self-test. */
err = viPrintf (dmm, "*TST?/n");
if(err<VI_SUCCESS) err_handler (dmm, err);
err = viScanf (dmm, "%t", buf);
if (err<VI_SUCCESS) err_handler (dmm, err);
printf ("Self-test response = %s/n/n", buf);
/* Check for system errors. */
err = viPrintf (dmm, "SYST:ERR?/n");
if (err<VI_SUCCESS) err_handler (dmm, err);
err = viScanf (dmm, "%t", buf);
if (err<VI_SUCCESS) err_handler (dmm, err);
printf ("System error response = %s/n/n", buf);
} /* end of main */
/*** Error handli ng function *** /
void err_handler (ViSession dm m, ViSt atus err)
{
char buf[1024] = {0};
Chapter 1
viStatusDesc (dmm, err, buf);
printf ("ERROR = %s/n", buf);
return;
}
Agilent E1412A Multimeter Module Setup 23
Notes:
24 Agilent E1412A Multimeter Module Setup
Chapter 1
Agilent E1412A Multimeter Application
Using This Chapter
This chapter provides multimeter application information in five parts.
• Measurement Tutorial.
• Measurement Configuration.
• Math Operations.
• Triggering the Multimeter.
• E1412A Multimeter Application Examples.
Measurement Tutorial
Chapter 2
Information
The E1412A is capable of making highly accurate measurements. In order
to achieve the greatest accuracy, you must take the necessary steps to
eliminate potentia l measurement errors. This section describes common
errors found in measurement s and gives suggestions to help you avoid these
errors.
DC Voltage Measurements
Thermal EMF
Errors
Thermoel ectri c v oltag e s are the mos t common source of erro r in low-level
dc voltage measurements. Thermoelectric voltages are generated when you
make circuit connections using dissimilar metals at different tempera tures.
Each m etal-to- m etal ju ncti o n form s a thermocouple, which generates a
voltage proportional to the junction temperature. You should take the
necessary precautions to minimize thermocouple voltages and temperature
variations in low-l evel voltage measurements. The best connections are
formed using copper-to-c opper crimped connections. Table 2-1 shows
common thermoelectr ic voltage s for connectio ns be tween di ssim ilar m etals.
Chapter 2
Agilent E1412A Multimeter Application Information 25
Tab le 2-1. T her m oelectri c Voltages
Copper-to-… Approx. µV/ ° C
Copper <0.3
Gold 0.5
Silver 0.5
Brass 3
Beryl lium C o ppe r 5
Aluminum 5
Kovar or Alloy 42 40
Silicon 500
Copper-Oxide 1000
Cadmium-Tin Solder 0.2
Tin-Lead Sol der 5
The E1412A input
terminals are
copper alloy.
Loading Errors
(dc volts)
Leakage Current
Errors
Measurement loading errors occur when the resistance of the deviceunder-test (
DUT) is an appreciable percenta ge of the mul timeter' s own input
resistance. The diagram below shows this error source.
To reduce the effects of loadi ng erro rs, and to minimize noise pickup, you
can set the multimeter's input resistance to greater than 10GΩ for the
100mVdc, 1Vdc, and 10Vdc ranges. The input resistance is maintained at
10 MΩ for the 100Vdc and 300Vdc ranges.
The multimeter's input capa citance will “charge up” due to input bias
currents when the terminals are open-circuited (if the input resistance is
10 GΩ). The multimeter's measuring circuitry e xhibi ts approximate ly 30pA
of input bias current for ambient temperatures from 0°C to 30°C. Bias
current wil l double (× 2) for every 8°C change in ambient temperatur e above
30°C. This current generates small voltage offsets depende nt upon the
source resistan ce of the device-under- test. This effect bec omes evident for a
source resistance of greater than 100kΩ, or when the multimeter's operati ng
temperature is significantly greater tha n 30°C.
26 Agilent E1412A Multimeter Application Information
Chapter 2
Rejecting Powe r
Line Noise
Voltages
A desirable characteristic of integrating analog-to-digital (A/D) converters
is their ability to reject spurious signals. The integrating techniques reject
power-line relate d noise present with a dc signal on the input. This is called
normal mode rejection or
NMR. Normal mode noise rejection is achieved
when the multimeter measures the avera ge of the input by “integrating” it
over a fixed period. If you set the integr ation time to a whole number of
power line cycles (
PLCs) thes e errors (a nd their harmonics) will average out
to approximately zero.
The E1412A provides thr ee A/D integration times (1, 10 and 100PLCs) to
reject power line frequ ency noise (and power-line frequency harmonics).
Power line frequency de faults to 60Hz unless you specifically set it to 50Hz
with th e
CAL:LFR command. The multimeter determines the proper
integration time bas ed on which power line frequency is set. Table 2-2
shows the noise rejection achieved with various configurations. S elect a
longer integration time for better resolution and increased noise rejection.
Table 2-2. Noise Rejection
Integration Time
Power Line
Cycles (PLCs)
0.02 400 µs (400µs) NONE
0.2 3ms (3ms) NONE
60 Hz (50Hz)
NMR
Common Mode
Rejection (
CMR)
116.7ms(20ms)60dB
10 167 ms (200ms) 60dB
100 1.67sec (2sec) 60dB
Ideally, a mult im eter i s com p lete ly i solat ed fro m eart h -ref ere nc ed circu i ts.
However, there is finite resistance between the multimeter's input LO
terminal and e arth ground as shown below. This can cause errors when
measuring small voltages which are floating relative to earth ground.
Chapter 2
Agilent E1412A Multimeter Application Information 27
Noise Caused by
Magnetic Loops
If you are making measurements near magnetic fields, you should take the
necessary precautions to avoid inducing voltages in the measurement
conductors. You should be especially careful when working near conductors
carrying large currents. Use twisted-pair connections to the multimeter to
reduce the no ise pi ckup loop a rea, or dre ss the i nput cables as c lose together
as possible. Also, loose or vibrating input cables will induce error voltages.
Make sure your input cables are tied down securely when operating near
magnetic fields. Whenever possible, use magnetic shielding materials or
physical separation to reduce problem magnetic field sources.
Noise Caused by
Ground Loops
When measuring voltages in circuits where the multimeter and the deviceunder-test are both referenced to a com mon earth ground but at different
points, a “ground loop” is formed. As shown below, any voltage difference
between the two ground referenc e poin ts (V
through the measurement leads. This causes errors such as noise and offset
voltage (usually power -line related), which are added to the measur ed
voltage.
The best way to eliminate ground loops is to ma intain the mu ltimeter's input
isolation from earth; do not co nnect the input terminals to ground. If the
multimeter must be earth-r efe renced, be sure to connect it, and the
device-under-te st, to the same common ground point. This will reduce or
eliminate any voltage dif ference between the devices. Also make sure the
multimeter and device-und er-te st are conne cted to the same ele ctr ical out let
whenever possible.
ground) cause s a current to flow
28 Agilent E1412A Multimeter Application Information
Chapter 2
Resistance Measurements
The E1412A offers two methods for measuring resistance: 2-wire and
4-wire ohms. For both methods, the test current flows from the input HI
terminal and then through th e resistor being mea sured. For 2-wire ohms, the
voltage drop a cross the resistor being measured is sensed internal to the
multimeter. The refore, input cable resistance is a lso measured. For 4-wire
ohms, separa t e “sen se” co n nect i ons are required. Sin ce no cu rr en t flow s in
the HI-LO “Sense ” terminal cables, the resistances in these cables d o not
give a measurement error.
The errors discussed pre viously for dc voltage measurements also apply to
resistance measurements. Additional error sources unique to resistance
measurements are discussed in the following sections.
4-Wire Ohms
Measurements
The 4-wire ohms method provi des the most accurate way to measure small
resistances. Errors due to test cable resistances and contact resistances are
reduced using this method. Four-wire ohms is often used in automated test
applications w here long cable lengths, numerous connections, or switches
exist between the multimeter and the device-under-test. The recommended
connections for 4-wire ohms measurements are shown below.
Chapter 2
Agilent E1412A Multimeter Application Information 29
Removing Field
Wiring Resistance
Errors
in 2-Wire Ohms
Measurements
Field wiring can cause an offset error in 2-wire resistance measuremen ts.
You can use the following procedure to minimize offset errors associate d
with field wiring resistance in 2-wire ohms measurements. You short the
field wiring at the DUT location and measur e the 2-wire lead resistance.
This value is subtra cted from subseque nt DUT 2-wir e ohms measurement s.
There are two ways to effectively null out the lead resistance. The first way
is to characte rize your f ield l ead re sistance by shorti ng the le ads at the DUT
location and measure and record the lead resistance. Then enable the math
operation and store the 2-wi re lead measurement value using the
CALCulate:NULL:OFFSet <value> command (CALC:STATe must be ON to
do this).
The following program shows SCPI examples used to store a
CONF:RES Set to 2-wire ohms func tion.
Short the lead resistance at the DUT locat ion.
READ? Measure the 2-wire ohms lead resistance.
Enter lead resistance value into computer.
CALCulate:FUNCtion NULL Set math operation to NULL.
CALCulate:STATe ON Turn math operati on ON.
CALCulate:NULL:OFFSet <value> Store the NULL offset value.
NULL value.
Subsequent 2-wire ohms measure ments will subtract the null offset value
from the meas urement thereb y remo v ing t he lead resi s tan ce from the
measurement.
The second way to store the 2-wire lead resista nce as the
NULL offset value
is to let t he multimeter automatic ally do thi s with th e first measur ement. The
first measurement made after
STATe is set to ON stores the measured value as the null offset.
CONF:RES Set to 2-wire ohms func tion.
Short the lead resistance at the DUT locat ion.
CALCulate:FUNCtion NULL Set math operati on to NUL L.
CALCulate:STATe ON Turn math operation ON.
READ? Measure the 2-wire ohms lead resistance.
Enter le a d re s is ta n ce value in t o comp u ter. The val u e is a ut o m a ti ca l ly
stored in the multimeter's null offset register.
Remove the short fr om the lead resistanc e at the DUT location
and connect leads to your DUT.
READ? Make a 2-wire ohms resista nce measurement.
Enter lead resistance value into computer. The NULL value is
subtracted from the measurement to more accurately provide the
DUT resistance.
CALCulate function is set to NULL and the
30 Agilent E1412A Multimeter Application Information
Chapter 2
Power Dissipation
Effects
When measuring resistor s designed for tempera ture measurements (or other
resistive devices with large temperature coefficients), be aware that the
multimeter will dissipa te some power in the device-under-test. If power
dissipation is a proble m, you should select the multimeter's next higher
measurement range to reduce the errors to acceptable levels. Table 2-3
shows several examples.
Table 2-3. DUT Power Dissipation
DUT
Range Test Current
100Ω 1 mA 100 µW
1kΩ 1mA 1mW
10 kΩ 100µA 100 µW
100kΩ 10µA10µW
1MΩ 5µA25µW
10 MΩ 500nA 2.5µW
Power at Full Scale
Settling Time
Effects
Errors in High
Resistance
Measurements
Making High-Speed
DC and Resistance
Measurements
Both the E1412A has the ability to insert au tomatic measurement settling
delays with the
resistance mea surements with less than 20 0pF of combined cable and devi ce
capacitance. This is particularly importa nt if you are measuring resistances
above 100k Ω. Settling due to RC time constant effect s can be quite long.
Some precision resist ors and multi-function calibrators use large parallel
capacitors (1000pF to 0.1µF) with high resistor values to filter out nois e
currents injected by their internal circuitry. Non-ideal capacitances in cables
and other devices may have much longer settling times than expec ted just by
RC time constants due to dielectric absorption ( soak) effec ts. Error s will be
measured when settli ng aft er the ini tial c onnection a nd af ter a rang e change.
When you are measuring lar ge resistances, signifi c ant errors can occur due
to insulation resistance and surface cleanliness. You should take the
necessary precautions to maintain a “clean” high-resistance system. Test
cables and fixtur es are susceptible to leak age due to moisture absorption in
insulating materia ls and “dirty” surfa ce films. Nylon and PVC are relative ly
poor insulators (10
13
(10
ohms). Leakage from nylon or PVC insulators can easily c ontribute a
0.1% error when measuring a 1 MΩ resistance in humid c onditions.
The multimeter incorporates an automatic zero measurement procedure
(autozero) to elimin ate internal thermal
measurement actually consists of a measurement of the input terminals
followed by a measu rement of the inte rnal offset v oltage. The in ternal offset
voltage error is subtra cted from the measurement for improved accuracy.
This compe nsa te s for offs et volt ag e chan ge s d ue to tem p era tur e. Fo r
maximum reading speed, turn au tozero off. This wil l more than double your
reading speeds for dc voltage, resista nce, and dc current functions. Autozero
does not apply to other measurement functions.
TRIG:DEL command. These delays are adeq u a te for
9
ohms) when compared to PTFE Teflon insulators
EMF and bias current errors. Each
Chapter 2
Agilent E1412A Multimeter Application Information 31
DC Current Measurement Errors
When you connect the multimeter in series with a test circuit to measure
current, a measu re ment error is introdu c ed . The erro r is cau sed b y the
multimeter's s eries burden voltage. A voltage is developed acro ss the wiring
resistance and current shunt resistance of the multimeter as shown below.
True RMS AC Measure ments
True RMS responding multimeters, like the E1412A, measure th e “heating”
potential of an applied signal. Unlike an “average responding ”
measurement, a true
dissipated in a resista nce, even by non-sinusoidal signa ls. The power is
proportional t o th e squa re of the m easured t rue
waveshape. An average responding ac multimeter is calibrated to read the
same as a tr ue
shapes, an ave rage respondi ng meter wi ll exhibit substantia l errors a s shown
below.
RMS measurement can be us ed to determine the power
RMS meter for sinewave inputs only. For other waveform
RMS voltage, in dependent of
The multimeter's ac volt age and ac current functions mea sure the ac-coupled
true
RMS value. This is in contrast to the a c+dc true RMS value shown above.
Only the “heating value” of the ac components of the input waveform are
measured (dc is rejected). For non-offset sinewaves, triangle waves, and
square waves, the ac and ac+dc values are equal since these waveforms do
not contain a dc offset. Non-symmetrical waveforms, such as pulse tr ains,
contain dc voltages which are rejected by ac-coupled tr ue
measurements.
An ac-coupled true
RMS measurement is desirable in situations where you
are measuring small ac signals in the presence of large dc offsets such as
when measuring ac ri pple present on dc power su pplies. There are si tuations,
however, where you might want to know t he ac+dc true
32 Agilent E1412A Multimeter Application Information
RMS
RMS value. You can
Chapter 2
determine this va lue by combining results from dc and ac measurements as
R
2
2
3
T
t
---
2
%
shown below. You should perform the dc measurement using at least 10
power line cycles of integration (6 digit mode) for best ac rejection
+
ac(dc)
ac2dc
+=
RMS value.
Crest Facto r Errors
(non-sinusoidal
inputs)
MS
A common misconception is “if an ac multimeter is a true RMS instrument,
the multimeter 's sinewave accuracy specifica tions apply to all waveforms. ”
Actually, the shape of the input signal can dra matically a ffect measurement
accuracy. A common way to describe signal waves hapes is crest factor.
Crest factor of a waveform is the ratio of its peak value to its
Common Crest Factors The crest fac tor for a sine wa ve i s =1.414. For a triangul ar wave the c rest
factor is = 1.732. For a square wave wit h pulse wi dth t and duty cycle T,
(see the graphic in the previous section), the crest factor is .
For a pulse train, the crest factor is appr oximately equal to t he square root of
the inverse of the duty cycle. In general, the greater the crest factor, the
greater the ene rgy contained in highe r frequency harmonics. Al l multimeters
exhibit measurement errors that are crest factor dependent. E1412A crest
factor errors are shown in the AC Characteristics Accuracy Specifications
listed in Appendix A with the excepti on that crest factor errors are not
specified for non sine wave input sign als below 100Hz when using the slow
ac filter (3Hz filter).
You can estimate the measurement error for a non-sinusoidal input signal
shown below:
Total Error = Error (sine) + Error (crest factor) + Error (bandwidth)
Error (sine): error for sinewave as shown in Appendix A, Specifications.
Error (crest factor): crest factor additiona l error as shown in Appendix A.
Error (bandwidth): estimated bandwidth error as shown below.
-(C.F.)
RROR
C.F. = signal's crest factor
f = signal's fundamental freque ncy
BW = multimeter's -3dB bandwidth
(1MHz for the E1412A)
(bandwidth)
-------------------------
4π BW×
f×
100
×=
Example Calculate the approximate measurement error for a pulse train input with a
crest factor of 3 and a fundamental frequency of 20kHz. For this example,
assume the multimeter's 90-day accuracy specifications:
±(0.05% + 0.03%).
Total Error = 0.08% + 0.15% + 1.4% = 1.6%
Chapter 2
Agilent E1412A Multimeter Application Information 33
Loading Errors
6
:
s
----
E
1
1M
1]
(ac volts)
In the ac voltage function, the input of the E1412A appears as a 1MΩ
resistance i n p aralle l with 100pF of capacitance. The cabli ng t hat y ou u se to
connect signals to the multi meter will also add additional capacita nce and
loading.
AC Measurements
Below Full Scale
For low frequencies where :
-100 R
Error (%) =
-------------------
R
s
×
+ 1MΩ
(f R
× ) 15(10
s
)Ω Hz
•≤
For any frequency:
rror (%) = 100 x [
R
= source resistance
s
f = input frequency
C
= input capacitance (100pF) plus cable capacitance
in
----------------------------------------------------------------- -
1 + (2π f C
in
⋅
(1MΩ)R
----------------------- -)
1MΩ+R
s
s
2
--------------------
(
1MΩ+R
Ω
)-
s
You can make the most accurate ac measurements when th e multimeter is at
full scale of the select ed rang e. Aut oran g in g occ ur s at ≤10% and ≥120% of
full scale. This enables you to measure some inputs a t full scale on one range
and 10% of full scale on the next higher range (e.g., 10V on the 10V range
or 10V on the 100V range). The accuracy will be significantly diff erent for
these two cases. For highest acc uracy, you should specify the rang e to assure
the lowest range possible for the measur ement (this turns autorange off).
Function and Range
Change Internal
Offset Correction
Temperature Coefficient
Errors
Overload Errors When you specify a new range in an overload condition, the internal offset
The E1412A uses an ac measure ment technique that measur es and re moves
internal offset voltages when you select a different function or range. The
next two secti ons d iscuss two ways the se off set e rrors can be gene rated and
how the multimeter deals with them.
If you leave t he multimeter in the same r ange for an extended pe riod of tim e,
and the ambient temperature changes significantly (or if the multim eter is
not fully warm ed up), the internal off se ts ma y chan ge. This tempera tur e
coefficient is typically 0.002% of range per °C and is automat ically removed
when you change functions or ranges .
measurement may be degraded for the selected range. Typically, an
additional 0.01% of range err or may be introduced. This additiona l error is
automatically r emoved when you remove the overload c ondition and change
function or r ange; the error remains if the function or range is not changed.
34 Agilent E1412A Multimeter Application Information
Chapter 2
Low-Level
V
2
Measurement
Errors
When measuring ac voltages less than 100mV, be aware that the se
measurements a re especially susceptible to errors introduced by e xtraneous
noise sources. Exposed (unshielded) cabling will act as an antenna and a
properly functioning multimeter will measure the signals received. The
entire meas urement path, includ i ng the power line, acts as a loop ant en na.
Circulating curre nts in the loop will create error voltages acr oss a ny
impedances in series with the multimet er's input. For this reason, you should
apply low-level ac voltages to the multimeter through shielded cables. You
should connect the shield to the input LO termi nal.
Make sure the multimeter and the ac source are connected to the same
electrical outl et whenever possible. You should also minimize the area of
any ground loops that cannot be avoided . Measurements of high-impedance
sources are more susceptible to noise pickup than measurements of lowimpedance sources . You can reduce the noi se pick-u p by placing a capac itor
in parallel with the multimeter's input terminals. You may have to
experiment to determine the corre ct capacitor value for your application
since this capacitance will contribute some loading e rror.
Most extraneous noise is not correl a ted with the input signal. You can
determine the error as shown below.
oltage Measured = Vin2+ Noise
Correlated noise, while rare, is especially detrimental because it will always
add directl y to the input signal. Measuring a low-level signal with the same
frequency as the local powe r line is a common situa tion prone to this error.
AC Turnover Errors Error s ar e gene rated when the multimeter 's i nput LO t erminal i s dr iven with
an ac voltage relative to earth. The most common situation where
unnecessary turnover errors are created is when the output of an ac calibrator
is connected to th e multimeter “ backwards. ” Ideal ly, a multim eter reads th e
same regardles s of how the sour ce is connec ted. Both sour ce and mul timeter
effects can degrade this ideal situation.
Because of the cap a ci tan ce b etw een the input L O termi n al and ear th
(approximately 200 pF for the E1412A) , the source will experien ce different
loading depending on how the input is applie d. The magnitude of the error
is dependent upon the source' s response to this loading. The multimeter' s
measurement circuit ry, while extensively shielded, responds differentl y in
the backward input case due to slight differences in stray capacitance to
earth. Because of this, the 100Va c and 3 00Vac ranges m ay la tch u p for high
voltage, high frequency “backward” inputs. Therefore, only drive the high
terminal when measuring a c voltages. You can use the grou nding techniques
described for dc common mode problems to minimiz e ac common mode
voltages (see Common Mode Rejection (CMR) on page 27).
Chapter 2
Agilent E1412A Multimeter Application Information 35
AC Current Measurement Errors
Burden voltage errors, which apply to dc current, also apply to ac current
measurements. However, the burden voltage for ac current is larger due to
the multimeter's se ries inductance and your measurement connections. The
burden voltage increa ses as the input frequency increases. Some cir cuits
may oscillate when performing current measurements due to the
multimeter's series inductance and your measurement connections.
Making High-Speed AC Voltage or Current Measurements
The multim eter' s ac vo ltage and ac current fun ct io ns imp l em en t three
different low -frequency filters. These filters allow you to trade low
frequency accuracy for faster reading speed. The fast filter settles in
0.1 seconds, and is useful for frequencies above 200Hz. The medium filter
settles in 1 second, and is useful for measurements above 20Hz. The
slow filter settles in 7 seconds, and is useful for frequencies above 3Hz.
With a few preca utio n s, you can p erform ac measurements at speed s up to
50 readings per second. Use manual rangi ng t o eli minate autoranging
delays. By setting the preprogrammed settling (trigger) delays to 0, each
filter will allow up to 50 readings pe r second. However, the measurement
might not be very accurate since the filte r is not fully settled. In applic ations
where sample-to-samp le leve ls vary widely, the medium filter (20Hz) will
settle adequ ately at almost 1 reading per second, and the fast filter (200Hz)
will settle adequate ly at almost 10 readings per second.
If the sample-to-sam p le le v e ls are si m i la r , li ttle settling ti me is r equired f or
each new reading. Under this specialized condition, the medium filter will
provide reduced accuracy results at 5 readings per second, and the fast filter
will provide reduced accur acy results at 50 readings per second. Additional
settli ng ti me may be req uired when t he dc le vel v aries from sample to s ample.
DC Blocking Circuitry The multimeter's dc blocking circuitry has a settling time constant of
0.2 seconds. This time const ant only a ffects measure ment accuracy whe n dc
offset levels v ary fro m s am p le to sam p le. If ma xim u m me as u rem en t speed
is desired i n a scanni ng syste m, you may want to add a n external dc blockin g
circuit to thos e channels with sig nificant dc voltages pr esent. This circ uit can
be as simple as a resistor and a capacitor.
Frequency and Period Measurement Errors
The multimeter uses a reciprocal counting technique to measure frequency
and period. This method generates co nstant measurement resolut ion for any
input frequen cy. The multime ter's ac vol tage measurement section per forms
input signal conditioning. All frequency counters are susceptible to errors
when measuring low-voltage , low- frequency signals. The effects of both
internal noise and exte rnal noise pickup are cri tic al when mea suring “slow”
signals. The error is inversely proportional to frequency. Measurement
errors will also oc cur if you attempt to m easure the frequency (or peri od) of
an input following a dc offset volta ge change. You must allow the
multimeter's input dc blocking capacitor to fully settle befor e making
frequency measurements.
36 Agilent E1412A Multimeter Application Information
Chapter 2
Measurement Configuration
This section contains information to help you configure the multimeter for
making measurements. The paramet ers discussed in this section give you
measurement flexibility when using the
AC Signal Filter The E1412A Multimeter has three different ac filters which enable you to
either optimize low frequency accuracy or achieve faster ac settling times for
ac voltage or ac current measurements. Only these functions use the ac filter.
CONFigure command.
Table 2-4. AC Signal Filters
DC Input
Resistance
AC Voltage or Current
Input Frequency
3 Hz to 300 kHz Slow filter 1 readi ng/7 seconds
20 Hz to 300 kHz Medium filter 1 reading/second
200 Hz to 300 kHz Fast filter 10 readings/second
NOTE: These reading rates account for only the AC filters behavior.
See Page
36 for the effect of DC blocking circuitry.
AC Filter
Selected
Max Reading Rate f or
Adequate Settling
• The ac filter selection is stored in volatile memory. Default is the
medium filter (20Hz - 300kHz) at power-on or after a module reset.
• The CONFigure and MEASure:<function>? commands automatically
select the medium (20Hz) filter.
• Use the [SENSe:]DETector:BANDwidth 3 | 20 | 200 | MIN | MAX
command to change the ac filter selection following a
command. The
MIN param eter will select the 3Hz filter and the MAX
parameter will selec t the 200Hz filter.
The E1412 Multimeter's input resistance is normally fixed at 10MΩ for all
dc voltage ranges to minimize noise pi ckup. You can set the input resista nce
to greater than 10G Ω for the 100 m Vdc, 1Vdc and 10 Vdc ranges to reduce
the effects of measurement loading errors. You select increased input
resistance using t he
INPut:IMPedance:AUTO ON command and this applies
to the dc voltage function only.
CONFigure
Chapter 2
Tab le 2-5. DC Voltage Input Resistance
DC Input Resistance
100 mV, 1V, 10V Ranges
INP:IMP:AUTO OFF
(DEFAULT)
INP:IMP:AUTO ON >10GΩ 10MW
10 MΩ 10 MΩ
DC Input Resistance
100V and 300V Ranges
• The input resistance setting is stored in volatile memory.
INPut:IMPedance:AUTO OFF is set at power-on and after a module
reset.
• The CONFigure command and the MEASure:<function>? command
automatically turn
after a
CONFigure command to set it ON.
Agilent E1412A Multimeter Application Information 37
AUTO OFF. Use INPut:IMPedance:AUTO O N
Resolution Resolution is expressed in te rms of number of digits the multimeter can
measure. You can set the resolution to 4½, 5½ or 6½-digits by specifying
the integration ti me (PLCs or apert ure time), which is the period the
multimeter's analog-to-digital (A/D) converter samples the input signal for
a measurement. To increase measurement accuracy and improve noise
rejection, specify more PLCs (longer inte gration time). To increase
measurement speed, specify fewer PLCs (shorter integrati on time).
This applies to all measureme nt functions.
The resolution for math opera tions is the same resolution for the
measurement function being measured. Table 2-6 illustr ates the correlation
between Number of Power Line Cycles and Resolution. See the tables
beginning on page 70 for detailed cross-reference of function ranges to
resolution as a function of NPLCs or Aperture Time.
Tab le 2-6. Re sol ution of Power Line Cycles
Number of Power Line Cycles (NPLC) Resolution
0.02 0.0001 X Full-Scale
0.2 0.00001 X Full-Scale
1 0.000003 X Full-Scale
10 0.000001 X Full-Scale
100 0. 0000003 X Full-Scale
• Resolution is stored in volatile memory. The multimeter sets itself to
10 PLCs at power-on or after a module res et.
• DC voltage ratio measurements use both the HI-LO input terminals
(input signal) and the HI-LO “Ω 4W Sense” terminals (the reference
signal). The resolution specified applies to the input signal applied to
the HI-LO input terminals for ratio measurements and not the
reference signal applied to the “Sense” terminals.
• Set the resolution using the following commands:
CONFigure:<function><range>|MIN|MAX,<resolution> |MIN|MAX
MEASure:<
[SENSe:]<
function>? <range>|MIN|MAX,<resolution>|MIN|MAX
function><resolution>|MIN|MAX
38 Agilent E1412A Multimeter Application Information
Chapter 2
Integration Time Integrat ion ti me is t he peri od durin g which t he mult imeter 's an alog-to -dig ital
(A/D) converter samples the input signal for a measurement. Integration time
affects the measurement resolution (for better resolution, use a longer
integration time), and measurement speed (for faster measurement, use a
shorte r in te g r ation tim e ).
• Integration time applies to dc voltage, dc current, resistance and
four-wir e resistance functions only. The integration time for the math
operations is the same as the integration time for the measurement
function in use.
• Except for FREQuency and PERiod functions, integration time is
usually specifi ed in number of power line cycles (NPLC). The defa ult
NPLC is 10. You can also specify an integr ation ti me in sec onds for dc
voltage, dc current, resistance, four-wire resistance, frequ ency an d
period using the aperture time command for eac h function. Aperture
time has a direct correlation to NPLC (except for the
PERiod functions which do not use NPLC) and is shown in the tables
beginning on page 70. See the
[SENSe:]PER:APER commands for setting frequency and period
aperture time.
[SENSe:]FREQ:APER and
FREQuency and
• The integration time is stored in volatile memory. The multimeter
selects 10 PLCs at power-on or after a module reset. See following
information for
FREQuency and PERiod aperture time.
• Only integral numbers of power line cycles (1, 10 or 100 PLCs)
provide normal mode (line freq uency noise ) rejection.
• Y ou cannot control the reading rate for ac measurements with
integration time because integ ration time is fixed at 10 PLCs for all ac
measurements. You must use a trigger delay to pace ac voltage and ac
current meas urements.
• NPLCs are not applicable to the FREQuency and PERiod functions.
Frequency and period measurements set resolution by specifying
aperture time. The aperture time for the
functions default to 100mS. Specify an aperture time of 10mS for
4 ½ -digits, 100 m S for 5½-digits or 1 second for 6½-digits of
resolution.
FREQuency and PERiod
• Set integration time using the following commands:
[SENSe:]<function>:NPLC <number>
(NPLC
[SENSe:]<
s are not applic abl e for the FREQ and PER functions)
function>:APER < se conds>
Chapter 2
Agilent E1412A Multimeter Application Information 39
Autozero Autozero applies to dc voltage, dc current and 2- wire resistance
measurements. The multimeter internally disconnects the input signal
following each measurement and takes a zero reading when aut o zero is
enabled. Aut o zero en abl ed is the defa ult se ttin g . It then sub t racts the zer o
reading from t he preceding re ading. This pre vents offset vol tages pr esent on
the multimeter's input c ircuitry from affecting measurement accuracy.
• Wh en au toz ero is dis abl ed (OFF), the multimeter takes one zero
reading and subtracts it from all subsequent measurements. It takes a
new zero reading each time you change function, range or integration
time. You can disable autozero on dc voltage, dc current an d 2-wire
ohms measurements only (it is always disa bled for ACV and ACI
functions). Autozero is always enabled when you select 4-wire ohms
or ratio measurements.
• The autozero mode is stored in volatile memory. The multimeter
automatically enable s autozero at power-on and after a module res et.
• Use the following command to disable autozero or select the ONCE
parameter. The
Autozero
ONCE perform s an immediate zer o meas u rem en t.
[SENSe:]ZERO:AUTO OFF |ONCE| ON
OFF and ONCE parameters have a similar effect.
OFF does not perform a new zero measurement. Autozero
Ranging You can let th e multimete r a utomaticall y sele ct t he range us ing aut oranging
or you can specify a range. If you specify an expect ed value for the signal
you are measuring, the multim eter selects the range to accommodate the
expected input signal and turns autoranging off. Specify a range for fast er
measurements to eliminat e the aut oranging time.
• The multimeter has autorange mode enabled at power-on and aft er a
module reset.
• Autorange thresholds:
Down range at <10% of range.
Up range at >120% of range.
• The multimeter will provide an overload indication by returning
"9.90000000E+37" if the input sig nal is greater than t he present
range can measure an d auto ranging is disab led or at the max imum ra nge
setting.
• The multimeter uses one “range” for all inputs between 3Hz and
300 kHz for the frequency and period functions. The multim eter
determines an internal r es olution based on a 3Hz signal. If you query
the range, the multimeter will r espond with
period measurements retur n
"0" with no input signal applied.
"3 Hz". Frequency a nd
• The specified range applies to the signal connected to the Input
terminals for ratio measurements. Autoranging is automatically
selected for reference voltage measurements on the Sense termina ls.
• Yo u can set the range using any of the following commands:
CONFigure:<function><range>|MIN|MAX|DEF,<resolution>|MIN|MAX|DEF
MEASure:<
[SENSe:]<
[SENSe:]<
function>? <range>|MIN|MAX|DEF,<resolution>|MIN|MAX|DEF
function>:RANGe <range>|MIN|MAX
function>:RANGe:AUTO OFF|ON
40 Agilent E1412A Multimeter Application Information
Chapter 2
Math Operations (CALCulate Subsystem)
This sec tions provides mor e information about using the math functions in
the
CALCulate command. The math operations and registers used to store
mathematical data are controlled using the
See Chapter 3, “Multimeter Command Reference”. There are two steps to
initiating a math operation.
1. Select the desired math function:
CALCulate:FUNCtion AVERage|DB|DBM|LIMit|NULL
2. Enable the selected math function by turning the calculate state on:
CALCulate:STATe ON
AVERage Function The AVERage function allows you to s tor e the mini mum and the maximum
reading from a group of measurements then calculate the average value of
all the readings. It also records the number of readings taken since the
average fun ction w as act iva te d.
• The first reading that the multimeter takes is stored as both the minimum
and maximum value following activation of the average function. The
minimum value is replaced with any subsequent value that is less. The
maximum value is replaced with any subsequent value that is greater.
CALCulate command subsystem.
NULL (Relative)
Function
• The minimum, maximum, average and count are stored in volatile
memory. The multimeter clears the values when the average function
is turned on, when power is turned off or after the module is reset.
• You use the following commands to activat e the average function and
query the results from the group of m easurements made following
activation.
CALCulate:FUNCtion AVERage Selects the average function.
CALCulate:STATe OFF|ON Activates the average function.
Take measurements here.
CALCulate:AVERage:MINimum? Read the minimum value.
CALCulate:AVERage:MAXimu m? Read the maximum value.
CALCulate:AVERage:AVERage? Read the average value.
CALCulate:AVERage:COUNt? Rea d the number of measurements.
A null measurement, also called relative, provides the difference between a
stored null v alue and the input sign al. One pos sible a ppl ication is in m aking
more accurate two-wire ohms measurements by nulling the te st lead
resistance.
Result = reading - null value
• Does not apply to the DC-to-DC Ratio measurements.
• The null value is adjustable and you can set it to any value between
0 and ±120% of the highest range, for the present function .
Chapter 2
• Clearing the NUL L value. The null value is stored in volatile memory;
the value is cleared when power is removed, after resetting the
multimeter or after a function change.
Agilent E1412A Multimeter Application Information 41
Two Ways to Store the
NULL Offset Value
• The null value is stored in the multimeter's Null Register. You can
enter a specific number into the null register using the
CALCulate:NULL:OFFSet < value> command. Any previously stored
value is replaced with the new value. Use the following commands to
activate the
must be enabled before you can store a value in the Null Register.
CONF:<function> Clears the null offset value.
CALCulate:FUNCtion NULL Set math function to NULL.
CALCulate:STATe ON Enable math operation.
CALCulate:NULL:OFFSet < value> Store a null offset value.
NULL function and input a null value. The calculate state
• Another way to enter the null value is to let the multimeter store the
first reading in the register. After you enable the
the
CALC: STA Te ON command, the fir st measure ment you obtain wi ll
be zero (if you have not stored a value as described in the previous
bullet). The measured value is stored as the
subtracted from itself to result in the zero reading. All subse quent
measurements will have the offset value subtracted from them. If you
previously stored a
CALC:NULL:OFFS <value> as in the commands in the above bullet,
the first reading does not overwrite the stored offset value but returns
with the previous of fset value subtracted.
CONF:<function> Clears the null offset value.
CALCulate:FUNCtion NULL Set math function to NULL.
CALCulate:STATe ON Enab le math operation.
** Set up the system to generate the offset of concern (e.g., short
** input leads for 2-wire ohms measurements that will follow).
READ? Measures and stores the offset value.
NULL offset value using
NULL function with
NULL offset value and
dB Measurements Each dB measurement is the diff erence between the input signal and a stor ed
relative value, with both values converted to dBm.
dB = reading in dBm - relative value in dBm
• Applies to dc voltage and ac voltage measurements only.
• The relative value is adjustable and you can s et it to any va lue be tween
0dBm and ±200.00dBm (well beyond the multimeter's measurement
capabilities).
• Clearing the relative value. The relative val ue is stored in volatile
memory; the value is cleared when power is removed, after the module
is reset or after a f unction change.
42 Agilent E1412A Multimeter Application Information
Chapter 2
Storing the dB
2
)
----
Reference Value
Do not confuse this opera tion with the dBm referen ce (DBM) function. See
the next section, “dBm Measurements”, and take note of the multimeter's
reference resistance setting (dB uses a reference level, dBm uses a reference
resistance).
• The dB reference value is stored in the multimeter's dB Relative
Register. Y ou can ent er a specific number into the register usi ng the
CALCulate:DB:REFerence <value> command. Any previously stored
value is replaced with the new value. Use the following commands to
activate the dBm function and input a reference value. The calculate
state must be enabled before you can stor e a value in the dB Relative
Register.
CALCulate:FUNCtion DB Set math function to DB.
CALCulate:STATe ON Enable math operation.
CALCulate:DB:REFerence <value> Store a dB reference value.
dBm Measurements The dBm operation calculates the power delivered to a resistance referenced
to 1 milliwatt.
Storing the dBm
Reference Resistance
Value
dBm =
0log
×
10
---------------------------------------------------------------------------------
(reference resistance) (1 mW
reading
×
• Applies to dc voltage and ac voltage measurements only.
• Y ou can choose from 17 different reference resistance values. The
factory setting for the reference resistance is 600Ω. Set your desired
value with the
The choices for
300, 500, 600, 800, 900, 1000, 1200, or 8000 ohms.
CALC:DBM:REF <value> command.
<value> are: 50, 75, 93, 110, 124, 125, 135, 150, 250,
• The reference resistance is stored in nonvolatile memory, and does not
change when power is removed or after the multimeter is reset.
Do not conf use this operati on with the dB reference (DB) function. See the
previous section, “dB Measurements”, and take note of the multimeter's dB
reference setting (dB uses a reference level, dBm uses a reference resistance).
• Use the following commands to activate the dBm function and input a
reference resistance value. The calculate state must be enabled before
you can store a value in the Reference Resistance Register.
CALCulate:FUNCtion DBm Set math function to DBm.
CALCulate:STATe ON Enable math operation.
CALCulate:DBM:REFerence <value> Store a dBm r eference.
Chapter 2
Agilent E1412A Multimeter Application Information 43
LIMit Function The limit test operation enables you to perform pass/fail testing against
limits you spe cify using the
commands.
CALCulate:LIMit:UPPer and LOWer
• Ap plies to al l meas urement funct ion s.
• Y ou can set the upper and lower limits to any value between 0 and
±120% of the highest range, for the present function. The upper limit
selected sh ould al ways be a more posi tive n umber th an the l ower limit.
The default upper and lower limit s are both “0”.
• The upper and lower limits are stored in volatile memory; the
multimeter sets both limits to 0 when power is removed from the
multimeter, after the multimeter is reset or after a f unction change.
• Y ou can configure the multimeter to generate a request for service
(SRQ) on the fir st occu rre n ce o f a failed reading. See the Sta tus
System Register Diagram in Figure 3-1 on page 154. Bits 11 and 12 of
the Questionable Data Regis ter provide the high and low limit error
signals that can be ena bled in t he sta tus byte to gene rate t he reque st for
service.
• Use the following commands to activate t he LIMit function and input
upper and lower limit values. The calculat e st ate must be enab led befo re
you can store a value in the Upper Limit and Lower Limit Registers.
CALCulate:FUNCtion LIMit
CALCulate:STATe ON
CALCulate:LIMit:UPPer <
CALCulate:LIMit:LOWer <
value>
value>
• The STATus:QUEStionable:CONDition register will indicate when an
upper or lower limit has been exceeded failing either a HI or LO limit
test. Use the
questionable register and determine what failure occurred. Sending this
command also clears the questionable data register (or send a Clear
Status
STAT:QUES[:EVEN]? command to query the status
*CLS command to clear the registe r before testing begins).
44 Agilent E1412A Multimeter Application Information
Chapter 2
Triggering the Multimeter
This section discusse s the multimeter's trigger system and outlines the
different triggering configurations and programming methods used to
control the tr igger system. Keep in mind tha t you do not hav e to program the
trigger system to make measurements. You can avoid having to learn the
information in this sect ion by using the default trigger config uration set by
MEASure and CONFigure commands. However, you will need the
information i n this section to take a dvantage of the flexibilit y of th e E1412A
trigger system when using the
The multimeter's trigger system synchronizes measurements with specified
internal or external events. These events include software trigger commands,
negati ve-going edges on the VXIbus trigger lines (TTLT0 - TTLT7), and
negative-going pulses on the multimeter's external trigger (“Trig”) BNC
connector. The trigger system also allows you to specify the number of
triggers that will be accepted, the number of readings per trigger (sample
count), and the delay between the trigger and each reading.
Figure 2-1 illustrates the multimeter's trigger system and the programming
commands that control the trigge r system. The multimeter operates in one of
two trigger states. When you are confi guring the multimeter for
measurements, the multimeter must be in the idle state. After configur ing
the multimeter, the multimeter must be placed in the wait-for-trigger state.
CONFigure command .
Chapter 2
Figure 2-1. Multimeter Triggering Flow Chart
Agilent E1412A Multimeter Application Information 45
Triggering the multimeter is a multi-step process that offers tr iggering
flexibility.
1. Y ou must configure the multimeter for the measurement by selecting
the function, range, r esolution, etc.
2. You must specify the source from which the multimeter will accept
the trigger. The multimeter will accept a BUS trigger from the
VXIbus, an exte rnal trigger from the front panel “Trig” BNC
connector or an immediate tri gge r from the multimeter's internal
trigger system.
3. Y ou must make sure that the multimeter is ready to accept a trigge r
from the specified trigger source (this is called the wait-for-trigger
state) by issuing a
always uses an immedia te trigger (see the flow chart in Figure 2-1 on
page 45).
READ? or INIT command. A MEASure command
The Tr igger Source The TRIGger:SOURc e <source> command configures the multimeter's
trigger system to respond to the specif ied source. The following trigger
sources are avai lab l e:
• BUS: Trigger source is the GPIB Group Execute Trigger (GET) or the
*TRG common command. Within the 75000 Series C mainframes, the
instrument whose trigge r source is “
addressed to listen will respond to the GPIB Group Execute Tr igger.
The
*TRG command differs from GET because it is sent to a speci fic
instrument not a group of instruments. NOTE: B-size controllers do
not support the BUS trigger (e.g., E1306A command module,
E1300/E1301A B-size mainfram es).
BUS” and was the last instrument
• EXTernal: Trigger source is the multi meter's external trigger BNC
connector (labeled “Trig” on the front panel). A falling (negative-going)
edge of the input signal triggers the multimeter. The external pulse
signal must be >1µs, + 5V maximum to 0V (TTL levels).
• IMMediate: Internal trigger is always present . If the multimeter is in
the wait-for-trigger state (
sends the trigger. The
automatically se t th e trigger so u r ce to
INITiate), TRIGger:SOURce IMMedi ate
MEASure a nd CONFigure commands
IMMediate.
• TTLTrg0 through TTLTrg7: Trigger source is the VXIbus TTL trigger
lines. The multimeter is trig gered on the falling ( negat ive- going) edge
of a TTL input signal. NOTE: B-size controllers do not support
VXIbus TTL triggers (e.g., E1306A Command Module,
E1300/E1301B B-Size Mainframes).
For exampl e, the follo w ing p rog ram stat em en t selects the externa l tri gge r
BNC connector as the trigger source.
TRIGger:SOURce EXTernal
You can change the trigger source only when the multimeter is in the idle
state. Attempting to c hange th e trigger sour ce while th e multimet er is in the
wait-for-tr igger state will generate the “Sett ings conflict” error.
46 Agilent E1412A Multimeter Application Information
Chapter 2
Checking the
Trigger Source
The TRIGger:SOURce? comman d retu rn s “BUS”, “EXT”, “IMM”, or
“TTLTn” to show the present trigger source. The string is sent to the
output buffer.
Note Note that a CONFigure or MEASure? command automatically sets the
trigger source to
with th e
or to TTLTrg<n>. The MEAS? command always uses T RIG:SOUR IMM.
TRIG:SOUR command to set the trigger source to BUS, EXTernal
IMMediate. You must follow the CONFigure command
External T riggering Use TRIGger:SOURce EXTernal to set the trigger source to external.
• The trigger signal must be a low-true pulse with a pulse width greater
than 1µs. The trigger signal level accepted is TTL (+5V maximum
negative-going to 0V). See the following diagram for the “Trig” input
requirement. The diagram also shows the “V M Complete” output you
can use to synchronize with a switch module.
• The multimeter takes one reading (or the number specified by
SAMPle:COUNt) for each external trigger received on the front panel
“Tri g” BNC connector.
Internal T riggering The trigger signal is always present in the internal triggering mode. This
mode is selected wi th the
TRIGger:SOURce IMMediate comman d.
• The multimeter takes one reading (or the number specified by
SAMPle:COUNt) immediately after a READ? or INITiate command.
The multimeter takes only one reading imm edi ately following a
MEAS? command.
• See the triggering process diagram in Figure 2-1 on page 45.
Chapter 2
Agilent E1412A Multimeter Application Information 47
Bus Triggering The multi meter is tr iggered from the VXIbus. T his mode is selected with the
TRIGger:SOURce BUS comman d.
• Use the *TRG command from the GPIB to trigger the mul timet er when
TRIG:SOUR BUS is used. The *TRG command will not be accep ted
unless the multimeter is in the wait-for-trigge r state.
• Y ou can also trigger the multimeter from the GPIB inter face by
sending the IEEE-488 Group Execute Trigger (GET) messa ge. The
multimeter must be in the wait-for-trigger state. Send a GET from a
Hewlett-Packard controller with the following command:
TRIGGER 70903
Note TRIG:SOUR BUS is not implemented on B-size resource managers, such
as the E1306A Command Module or the E1300A/E1301A B-size
Mainframes.
The Wait-for-Trigger
State
You must place the multimeter in the wait-for-trigger state after you have
configured it and selec ted a trigger source. A trigger will not be accepted
until the multimet er is in this stat e. The measurement seque nce begins when
the multimeter is in the wait-f or-trigger state and it receive s a trigge r.
You can place the multimeter in the “wait-for-trigger” state by executing
one of the following commands:
READ?
INITiate
Note The multimeter require s approximately 20ms of set up time after you send
a command to ch ang e to the “w ait- fo r-trigg er” stat e. An y trigg ers that
occur during this set up time are ignored.
The Trigger Count The TRIGger:COUNt <number> command sets the number of triggers the
multimeter will accept in the wait-for-trigger state before returning to the
idle state. Use the number parameter to set the trigger count to a value
between 1 a nd 50,000. The
count to 1.
Substituting
Substituting
MIN for the number parameter sets the trigger count to 1.
MAX for the number parameter sets the tri gger count to 50,000 .
MEASure a nd CONFigure commands set tr igger
48 Agilent E1412A Multimeter Application Information
Chapter 2
Example: Setting the
Trigger Count
In the following example, one DC voltage measurement is made each time the
multimeter's external trigger BNC connector is pulsed low. After 10 external
triggers are received, the multimeter returns to the idle state.
Checking the
T r igger Count
Inserting a
Trigger Delay
dimension array
CONF:VOLT:DC
TRIG:SOUR EXT
TRIG:COUN 10
READ?
timeout may occur
enter statement
Dimension computer array.
Function: DC voltage.
Trigger source is exter nal BNC on multimeter front
panel.
Multimeter will accept 10 external triggers (one
measurement is taken per trigger).
Place multimeter in wait-for-trigger state; make
measurements wh en external t rigger is rec eived; send
readings to output buffer.
May require INIT, monitor the status byte for
completion (s tandar d event bit 0), FET C? to tr ansfe r
readings to the output buffer (vs. READ?).
Enter readings into computer.
The TRIGger:COUNt? [MINimum|MAXimum] command returns one of the
following numbers to the output buf fer:
• The present trigger count (1 through 50, 000) if neithe r MIN nor MAX is
specified.
• The minimum trigger count available (1) if MIN is specified.
• The maximum trigger count available (50,000) if MAX is specified.
The TRIGger:DELay <seconds> command inserts a delay between the
trigger and each measurement . This includes a delay between the trigger and
the first measurement and again before each subsequent mea surement when
sample count is greater tha n one. The
delay to a value between 0 and 3600 seconds (with 1µs resolution) .
<seconds> time parameter sets the
Example: Inserting a
Tr igger Delay
Substituting
Substituting
MIN for the <seconds> time parameter sets the trigger delay to 0.
MAX for the <seconds> time parameter sets the trigger delay to
3600 seconds.
In the following example, the multimeter will accept 5 triggers from the
external trigge r BNC connector. Four measurements are taken per trigger
(sample count is set to 4) and the trigger delay is 2 seconds.
dimension array
CONF:VOLT:DC
TRIG:SOUR EXT
TRIG:COUN 5
SAMP:COUN 4
TRIG:DEL 2
READ?
timeout may occur
enter statement
Dimension computer array.
Function: DC voltag.e
Trigger source is exter nal BNC on multimeter front
panel.
Multimet er will accept 5 external triggers (one
measurement is taken per trigger).
Take 4 measurement s for each trigger.
Wait 2 seconds between trigger and start of first
measurement and ea ch s ubsequent measurement till
sample count reached.
Place multimeter in wait-for-trigger state; make
measurements when external triggers are received;
send readings to output buffer.
May require INIT, monitor the status byte for
completion (s tandar d event bit 0), FET C? to tr ansfe r
readings to the output buffer (vs. READ?).
Enter readings into computer.
Chapter 2
Agilent E1412A Multimeter Application Information 49
Default Delays If you do not specify a trigger delay, the multimeter automa tically
determines a delay time (default delay) based on the present measurement
function, range, resolution, integration tim e and AC filter bandwidth setti ng.
The delay tim e is act ually the se ttling tim e req uired be fore measurement s t o
ensure measurement accuracy. The default delay time is automatically
updated whenever you change the func tion or range. Once you specify a
delay time value, however, the value does not change until you specify
another valu e, reset the multimeter or do a
table below shows the default tr igger delay times for all functions. This
delay will occur before each measurement (see the trigger system diagram
in Figure 2-1 on page 45).
NOTE: Y ou can s pecif y a short er de lay time th an the de faul t values s hown.
However, the shorter set tling time may not pro duce accurate measurements .
Tab le 2-7. Defau l t Trigger Delays
Default Trigger Delays for DC Voltage and DC Current (all ranges):
Integration Time Trigger Delay
NPLC ≥11.5ms
NPLC <1 1.0m s
Default Trigger Delays for 2-Wire and 4-Wire Resistance:
CONF or MEAS command. The
Range Trigger Delay
(For NPLC ≥1)
100Ω 1.5m s 1.0 ms
1kΩ 1.5m s 1.0 ms
10 kΩ 1.5 ms 1.0ms
100kΩ 1.5m s 1.0 ms
1MΩ 1.5m s 10ms
10MΩ 100ms 100ms
100 MΩ 100ms 100ms
Default Trigger Delays for AC Voltage and AC Current (all ranges):
AC Filter Trigger Delay
3Hz - 300kHz filter 7.0sec
20Hz - 300kHz filter 1.0sec
200Hz - 300 kHz filter 600ms
Default Trigger Delay for Frequency and Peri od:
Trigger Delay
(For NPLC <1)
50 Agilent E1412A Multimeter Application Information
1.0s
Chapter 2
Querying the
Delay Time
The TRIGger:DELay? [MINimum|MAXimum] command returns one of the
following numbers to the output buf fer:
• The present trigger delay (1µs through 3600 s econds) i f MIN or MAX is
not specified.
• The minimum trigger delay available (1µs) if MIN is specified.
• The maximum trigger delay available (3600 seconds) if MAX is
specified.
The Sample Count The SAMPle:COUNt <number> command designates the number of
readings per trigger . The number param eter sets the number of readings to
a value between 1 and 50,000.
Example: Setting the
Sample Count
Checking the
Sample Count
Substituting
trigger to 1. Substituting
readings per trigger to 50,000.
In the following example, 10 DC voltage measure ments are made when the
multimeter's exte rnal trigger BNC connector is pulsed low. After the
10 readings are taken, the multimeter returns to the idle state.
dimension array
CONF:VOLT:DC
TRIG:SOUR EXT
SAMP:COUN 10
READ?
timeout may occur
enter statement
The SAMPle:COUNt? [MINimum |MAXimum] command returns one of the
following numbers to the output buf fer:
MIN for the number parameter sets the number of readings per
MAX for the number parameter sets the number of
Dimension computer array.
Function: DC voltage.
Trigger source is exter nal BNC on multimeter front
panel.
Specify 10 readings per trigger.
Place multimeter in wait-for-trigger state; make
measurements wh en external t rigger is rec eived; send
readings to output buffer.
May require INIT, monitor the status byte for
completion (s tandar d event bit 0), FET C? to tr ansfe r
readings to the output buffer (vs. READ?).
Enter readings into computer.
• The present sample count (1 through 50,000) if neither MIN nor MAX
is specified.
Chapter 2
• The minimum sample count available (1) if MIN is specified.
• The maximum sample count available (50,000) if MAX is specified.
Agilent E1412A Multimeter Application Information 51
E1412A Multimeter Application Examples
This section contains example programs that demonstrate several applications
using the E1412A Multimeter. The examples described in this section list only
the SCPI commands (see Chapter 3, “Multimeter Command Reference”)
required to perform the application. The programming language is not
included in print but C and Visual Basic programs are included on the
VXIplug&play driver media under the subdirectory “examples” .
VTL Software
(VISA)
Application example programs provided with the E1412A Multimeter are
written using VTL 3.0 (VISA Transition Language). VISA (Virtual
Instrument Software Architecture) is an I/O library that c an be used to create
instrument drivers and I/O applications. Application programs written with
VTL function calls can use VXIplug&play drivers (or SCPI commands) in
systems that have the VTL I/O layer. VTL allows you to use software from
different vendors together on the same platfo rm. VTL can be used for I/O
application development on Microsoft
VXI, GPIB-VXI, and GPIB interfaces. VISA 1.0 provides more VISA
functionality and is fully operational on Windows
®
Windows 3.1, and is supported on the
®
95 and Windows NT®.
Example Pro grams Example progra ms are provided on the VXIplug&play media. These
programs have been compiled and teste d using Microsoft Visual C++
Version 1.51 for the C programs and Microsoft Visual Basic 3.0.
C Programs All projects written in C programming language require the following
settings to work properly.
Project Type: QuickWin application (.EXE)
Project Files : <source code file name>.C
[drive:]\VXIPNP\WIN\LIB\MSC\VISA.LIB ( Microsoft compiler)
[drive:]\VXIPNP\WIN\LIB\BC\VISA.LIB (Borland comp iler)
Memory Model: Options | Project | Compiler | Memory Model
⇒ Large
Directory Paths: Options | Directories
Include File Paths:
Library File Paths: [drive :]\VXIPNP\WIN\LIB\MSC (Microsoft)
Example Programs:
[drive:]\DSCPI\e1412 (on driver CD)
[drive:]\VXIPNP\WIN\INCLUDE
[drive:]\VXIPNP\WIN\LIB\BC (Borland)
Visual Basic Programs All proj ects wr itten in the Visual Basic programming language require the
following settings to work properly.
Project Files :
<source code file name>.FRM
[drive:]\VXIPNP\WIN\INCLUDE\VISA.BAS
Note If using W indows 3. 1, change “spc ” to “ cps” in th e Memory I /O Operati ons
section of V ISA.BAS
52 Agilent E1412A Multimeter Application Information
Chapter 2
Hardware Used 486 IBM compatible compute r runni ng Windows 3.1. The compute r has an
82341 GPIB interface and SICL/Windows 3.1 and Windows NT for GPIB
software. The VXI modules were loaded in a VXI C-size mainfr ame using
an E1406A or B-size mainframe with E1306A Command Module as
resource manager connected to the computer via the 82341 GPIB card.
Making Multimeter
Measurements
This section provides four programs that demonstrate different ways of
making measurements and retrieving the readings. SCPI command
sequences for each progra m are cont ained in the boxes. The four programs:
1. Use the
2. Make several externally triggered measurements.
3. Maximize measurement speed on multiple measurements.
4. Maximize me asu rem en t accuracy on multipl e me as urements.
NOTE: Review the section titled “Triggering the Multimeter” beginning on
page 45 to fully understand the triggering system.
MEASure command to make a single measurement.
MEASure Command The simplest measurement method is using the MEASure command which
configures the function to be measured, initiates the measurement(s) and
places the reading(s) directly into the output buffer. You then must provide
the I/O construct to retrieve the readings and enter them into the computer.
One
MEASure command will initiate multiple measurements if the trigger
count or the sample count is greater than 1. The measurement process stops
when the output buffer fills if readings are not retrieved fast enough. The
measurement process restarts when there is again room to store readings in the
output buffer.
READ ? Co m m a n d The READ? command requires that you configure the multimeter for the
function you want to measure prior to issuing the command. The command
initiates the measurement(s) and places the reading(s) directly into the output
buffer like the
to retrieve the readings and enter them into the computer. One
command wi ll initiate multiple measurements if the trigger count or the
sample count is greater than 1. The measurement process stops when the
output buffer f ill s if re adings a re not r etrie ved f ast enou gh. Th e measur ement
process restarts when there is room to store readings in the output buffer.
MEASure co mmand. You then must provide the I/O construct
READ?
Chapter 2
INIT and FETC?
Commands
The READ? command is broken down into two operations with the INIT a nd
FETC? commands. The INIT and FETC? commands require that you
configure the multimet er for the function you want to measure prior to
issuing the commands. The
places the re ading(s) int o the multimete r's RAM memory. This memory will
hold a maximum of 512 r eading s. You use the
the readings from memory to the output buffer. You then must provide the
I/O construct to retr ieve the reading s and e nter them into th e compute r. One
INIT command will initiate m ultiple meas urements if th e trigger count or the
sample count is greater tha n 1. If more than 512 measurements are made,
only the last 512 readings are sto red. Use the
than 512 readi ngs since readings are immediately p ut into the output buffer
and retrieved with an I/O constr uct you supply. The measurement process
stops when the output buffer fills if readings are not retrieved fast enough.
The measurement process restarts when there is again room to store readings
Agilent E1412A Multimeter Application Information 53
INIT command initiates the measurement(s) and
FETC? c ommand to trans fer
READ? command for more
in the output buffer.
Measurement Fo rm at Readings in the output buffer have the following characteristic s:
• Readings sent to the output buffer can consist of two different lengths
(bytes or characters) in Real ASCII format:
±1.23456E±12 LF or
±1.234567E±12
LF
• Each measurement is terminated with a Line Feed (LF). The GPIB
End-or-Identify (EOI) signal is sent with the last byte transferred. If
multiple measurements are returned, the measurements are separated
by commas and EOI is sent only with the last byte. For example:
±1.23456E±12 LF,±1.234567E±12 LF,±1.23456E±12 LF E O I
• The multimeter's internal memory stores 512 readings maximum.
MEASURE1
Source Code File
Comments • The MEASure command configures the multimeter for the function
MEASURE2
Source Code File
Use the MEAS Command to Make a Single Measurement
*RST
MEAS:VOLT:DC?
enter statement
Reset the multimeter.
Configure dc volts (default settings) and measure
retrie ve the reading from the multimeter.
Enter reading into computer
specified and initia tes the measurement. The reading is stored in the
output buffer and you must provide the I/O construct to retrieve the
reading and enter it into the computer.
Making External ly Triggered Measurements (m u lt iple triggers/sa mples)
*RST
CONF:VOLT:DC 18
TRIG:SOUR EXT
TRIG:COUN 3
SAMP:COUN 10
INIT
FETC?
enter statement
Reset the multimeter.
Configure for dc volts, expected input = 18V.
Set trigger s ource to external.
Set trigger count to 3.
Set sample coun t to 10 per trigger.
Puts multimeter in wait-for-trigger state. EXTer nal
triggers occur here to initiate measurements.
Measurement s are stor ed in multimeter internal
memory.
Transfer measurements from the multimeter internal
memory to the output buffer and retrieve them with
the co m p u t er.
Enter reading into computer.
Comments • You must provide a TTL external trigger signal to the E1412A front
panel “Trig” input BNC. Measurements are triggered by low pulses of
this si gnal. Each trigger r esults in 10 readings.
• The CONFigure command configures the multimete r for the function
specified. This
18 (expected input is 18V; the multimete r sets a ran ge to
accommodate that input which will be 100V). It does not initiate the
measurement.
54 Agilent E1412A Multimeter Application Information
CONFigure command specifies a range parameter of
Chapter 2
• Trigger source (TRIG:SOUR) is set for an external trigger. A trigger
count (
exte r n al trig gers.
TRIG:COUN) of 3 is set; the multimeter will accept three
• The sample count (SAMP:COUN) is set for 10 samples per trigger.
• The INITiate c ommand p uts the mul time ter in the wai t-f or -tr igge r sta te.
The tri gger source is an “
trigger an d input it on the “Ext Trig” BNC connector which initiates
the measurement process. This will cause the multimeter to make
30 measurements; 10 samples for each of three triggers.
EXTernal” hardware trigger. You provide this
• The FETCh? command cause s the read in g s to be tran sferred to the
output buffer and you must provide the I/O construct to retrieve the
readings and enter them into the computer.
MEASURE3
Source Code File
Comments • The CONFigure command configures the multimeter for the function
Maximizing Measurement Speed (no trigger delay, short integration time)
*RST
CONF:VOLT:DC 18
CAL:ZERO:AUTO OFF
TRIG:SOUR IMM
TRIG:COUN 3
SAMP:COUN 10
INIT
FETC?
enter statement
specified. This
18 (expected input is 18V; the multimete r sets a ran ge to
accommodate that input which will be 100V). It does not initiate the
measurement.
CONFigure command specifies a range parameter of
Reset the multimeter.
Configure for dc volts, expected input = 18V.
Turn off autozero (makes fas ter measurements).
Set the trigger source to immediate.
Set trigger count to 3.
Set sample coun t to 10.
INITiate command puts multimete r in
wait-for- tri gger stat e; int erna l trigger immediate ly
occurs here and measur ements are stored in the
multim eter's in t er n a l me m ory.
Transfer measurements from the multimeter's
internal me mory to the output buffer and retrieve
them with the computer.
Enter reading into computer.
• The autozero function is disabled to speed up the measurement
process. See the
Reference fo r more informati on.
CALibrate:ZERO:AUTO command in the Command
Chapter 2
• Trigger source (TRIG:SOUR) is set for immediate internal triggers.
A trigger count (
three triggers.
TRIG:COUN) of 3 is set; the multimeter will accept
• The sample count (SAMP:COUN) is set for 10 samples per trigger.
• The INITiate command puts the multimeter in the wait- for-trigger
state. The trigger source is “
trigger source. This trigger occurs immediately and cause s the
measurement process to begin. This will cause the multimet er to make
30 measurements; 10 samples for each of three internal triggers.
IMMediate” which specifies the internal
• The FETCh? command cause s the read in g s to be tran sferred to the
output buffer and you must provide the I/O construct to retrieve the
readings and enter them into the computer.
Agilent E1412A Multimeter Application Information 55
MEASURE4
Source Code File
Comments • The CONFigure command configures the multimeter for the function
Maximizing Accuracy (most accurate resolution, longer integration time)
*RST
CONF:VOLT:DC AUTO,MIN
TRIG:SOUR EXT
TRIG:COUN 2
SAMP:COUN 10
READ?
enter statement
specified. This
minimum resolution (the smalle st resolution value which is the best
resolution). It does not initiate the measurement.
CONFigure command specifies autorange and
Reset the multimeter.
Configure for dc volts, autora nge, minimum
resolution (longest integration time).
Set trigger s ource to external.
Set trigger count to 2.
Set sample coun t to 10.
Initiate measurements putting the m directly
into output buffer; retrieve them with the
computer.
Enter reading into computer.
• Specifying a small value for resolution provides the most accurate
measurements. This will increase the inte gration time (NPLCs) and
therefore req ui re mo re time fo r the measu re ments.
• Trigger source (TRIG:SOUR) is set for an external trigger. A trigger
count (
exte r n al trig gers.
TRIG:COUN) of 2 is set; the multimeter will accept two
• The sample count (SAMP:COUN) is set for 10 samples per external
trigger.
• The READ? command puts the mu ltimeter i n the wa it-f or -tri gger sta te.
When the first external trigger is received, the measurement process
begins. This will cause the multimeter to make 10 measurements for
the first external trigger, go to the wait-for-trigger state and take 10
measurements for the second external trigger when received.
• The readings are stored in the output buffer and you must provide the
I/O construct to retr ieve the re adings and en ter the m into t he compute r.
• This example uses the READ? command. Measurements are initiated
with the
trigger state. Measurement occurs when the tri gger arrives and read ings
are subsequently stored directly in the outp ut buffer and must be
retrieved by the computer with an I/O construct you supply. An
alternative way of initiating measurements is to use the
command as done i n t he previo us e xample. Meas urements are mad e and
stored in the multimeter's internal memory and must be retrieved using
the
You must be careful when using the
Internal memory stores a maximum of 512 readings; the oldest readings
exceeding 512 are lost.
READ? command which puts the multimeter in the wait-for-
INITiate
FETCh? command which transfers the readings t o the output buff er.
INITiate and FETCh? commands.
56 Agilent E1412A Multimeter Application Information
Chapter 2
Synchronizing the
Multimeter With a
Switch Module
This program example demonstrates how to synchronize the multimeter
with a switc h module. F or the E1412A it use s the TTL t riggers f rom the VXI
backplane to trigger the multimeter and advance the channel scan list. The
example uses the E1476A 64-Channel Multiplexer Module but will also
work with any switch module as long as the channel list is spe cified
properly. Figure 2-2 illustrates the C-size set up. The switch module
(multiplexer) and multimeter use the VXI backplane to communicate the
trigger and VM Complete signals to each other to synchronize the scan.
Figure 2-2. E1412A Multimeter and Switch Module Synchronization
Figure 2-3 shows the E1312A se t up using external triggering. (Note: the
E1312A is obsolete and no longer supported. Figure 2-3 is for inf ormation
only.) B-size command modules do not support VXIbus TTL triggers.
Figure 2-3. E1312A Multimeter (obsolete and unsupported) and Switch Module Synchronization
Chapter 2
Agilent E1412A Multimeter Application Information 57
This example monitors the switc h module's status system. The switch
module's status system (E1476A) is shown in Figure 2-4. This example
program enables t he switc h's “ Scan Comp lete” b it t o allow it t o set the OPR
bit in the switc h's status byte when the scan is finished. The program
repeatedly reads the switch modul e' s status byte until the OPR bit gets set
which returns a status byte val ue of 128. This indicates the switch module
has completed all closures in the scan list. The multimeter's
FETC?
command cau ses the mu ltim et er t o trans fe r read i ng s to the out p ut buf fer
after completing the last measurement. Readings are entered into the
computer using an I/O construct you pr ovide.
NOTE: This is t he E1476A Switch Module’s status system.
See Figure 2-5 for the E1412A Multimeter status system.
Figure 2-4. E1476A Switch Module Status System
58 Agilent E1412A Multimeter Application Information
GPIB
Chapter 2
E1412A SCAN
Source Code File
SCPI command sequences for the program are as follows.
**** Set up the Multimeter ****
*RST
*CLS
CONF:VOLT 12,MIN
TRIG:SOUR TTLT2
TRIG:COUN 8
TRIG:DEL 0.01
OUTP:TTLT1:STAT ON
CALC:FUNC AVER
CALC:STAT ON
*OPC?
INIT
Reset the multimeter.
Clear the multimeter's st a tus registers.
Configure for dc volts, 12V input , min r es .
Let switch closure trigger multimeter.
Multimeter will accept 8 triggers.
Use a 10 ms delay before each
Output VM Complete to switch via TTLT1.
Select the math function AVERage.
Enable math operations.
Wait until above commands are processed. Read the
response to th e *OPC? command fr om multimeter.
Puts multimeter in the "wa it-for-trigger" state ;
trigger source is TTLTrig2 line OUTPut by the
switch.
measurement,
**** Now set up the switch module ****
*RST
*CLS
ABOR
STAT:OPER:ENAB 256
OUTP:TTLT2:STAT ON
TRIG:SOUR TTLT1
SCAN (@100:107)
*OPC?
INIT
Reset the s w it ch m odu l e.
Clear the switch module's status registers.
Abort any sw itch operation in progress.
Enable bit 8 of operation status register.
Enable switch cl osure to trigger multimeter.
Allow VM Complete to advance the scan.
Specify a switch module scan list.
Wait until above commands are processed. Read the
response to th e *OPC ? command from switch.
Starts scanni ng by closure of the first channel in the
scan list; sends output signal to multimete r via
TTLTrig2 to trigger a measurement; multimeter
sends TTLT1 (VM Complete) back to switch module
to advance scan to the next channel; measurements
are stored in mult imeter internal memory.
*****************************************************
Read switch's status byte until all channels are scanne d and scan
complete (bit 8 in the operatio n status register) sets the OPR bit in the
status byte.
*****************************************************
Retrieve the readin gs from the multimeter.
FETC?
Transfer measurements from the multimeter internal
memory to the output buffer and retrieve them with
the co m p u t er.
Retrieve the AVERage math operation response from the
multimeter.
CALC:AVER:AVER?
CALC:AVER:MAX?
CALC:AVER:M IN?
Retrieve the ave rage measurement value.
Retrieve the maxi mum measurement value.
Retrieve the minimum measurement value .
Check the multimeter for system errors.
SYST:ERR?
Retrieve the system error response from the
multimeter.
Chapter 2
Agilent E1412A Multimeter Application Information 59
Multimeter Status
System Exampl es
There are two program examples that demonstrate how the E1412A
Multimeter status sys tem works. In both programs the status byte is
repeatedly read to identify when actions by the Multimeter set the
appropriate bit in the status byte. The computer can identif y when readings
are available by monitoring the status byte and can retrieve readings when
they are available.
Figure 2-5 illustra tes the E1412A status system. A Questionable Data
Register, an Output Buffer and a Standard Event Register each have a
respective sta tus bit in the Status Byte Register. The Output Buffer sets the
MAV bit when there is data available such as measurement readings or a
response to a SCPI query command. The Questionable Data Register and
Standard Event Register r equire you to “unmask” the bits you want to be
OR'd into a summary bit which sets the respective bit in the Status Byte. You
must also “unmask” the status bits you want OR'd into a summary bit to set
the Service Request bit (SRQ) if you want to generate an interrupt. The
example programs illust rate this requirement.
Figure 2-5. E1412A Multimeter Status System
60 Agilent E1412A Multimeter Application Information
GPIB
Chapter 2
SYNCHOPC
Source Code File
This program has the multi meter take 10 measurements. The S tandard Event
bit (ESB) in the statu s byte (see Figure 2-5 on page 60) is monitored to det ect
when the operation is c omplete. Readings are transf erred to the output buff er
by a
FETC? command and retrieved by the computer following the
indication th at the opera tio n has complete d. The Multi meter t hen calcula tes
the average, minimum and maximum reading.
**** Set up the Multimeter ****
*RST
*CLS
*ESE 1
CONF:VOLT 15
VOLT:DC:NPLC 10
TRIG:COUN 10
TRIG:DEL .01
CALC:FUNC AVER
CALC:STAT ON
INIT
*OPC
Reset the multimeter.
Clear the multimeter's st a tus registers.
Enables bit 0 of the mult imeter's standard event
register.
Configure for dc volts, expected input of 15V.
Set number of power line cycles to 10.
Multimet er will accept 10 triggers .
Use a 10ms delay before each
Select the math function AVERage.
Enable math operations.
Puts multime ter in wait-for-trigger state; tr ig source
is "IMM"; internal trigge r occurs "i mmediate ly" and
measurements are stored in multimeter internal
memory.
Waits for al l measurements to complete then sets bit
0 in the standard event register (the operation
complete bit)
measurement.
Loop
SPOLL - read the multimeter 's status byte until bit 5 (ESB) goes high.
End Loop
FETC?
Transfer measurements from the multimeter internal
memory to the output buffer and retrieve them with
the co m p u t er.
Retrieve the AVERage math operation response from the multimeter.
CALC:AVER:AVER?
CALC:AVER:MAX?
CALC:AVER:M IN?
Retrieve the ave rage measurement value.
Retrieve the maxi mum measurement value.
Retrieve the minimum measurement value .
Check the multimeter for system errors.
SYST:ERR?
Retrieve the system error response from the
multimeter.
Chapter 2
Agilent E1412A Multimeter Application Information 61
SYNCHMAV
Source Code File
This program h as the multimet er take 10 meas urements just like SYNCHOPC.
Readings are transferred to the output buffer by a
FETC? command. The
Message Available bit (MAV) in the status byte (see Figure 2-5 on page 60) is
monitored to detect when the measurements are complete and the Multimeter
has readings i n the output buffer . Readings are re trieved by the comput er when
the MAV bit in the statu s byte indica tes the measurements are complete and
readings are available. The Multimeter then calculates the average, minimum
and maximum reading.
**** Set up the Multimeter ****
*RST
*CLS
CONF:VOLT 15
VOLT:DC:NPLC 10
TRIG:COUN 10
TRIG:DEL .01
CALC:FUNC AVER
CALC:STAT ON
INIT
FETC?
Reset the multimeter.
Clear the multimeter's st a tus registers.
Configure for dc volts, expected input of 15V.
Set number of power line cycles to 10.
Multimet er will accept 10 triggers .
Use a 10ms delay before each
Select a math function.
Enable the math operations.
Puts multimeter in wait-f or-trigger s tate; trigger
source is "IMM"; internal trigger occurs
"immediately" and measurements are stored in
multim eter in t er n a l me m ory.
Transfer measurements from the multimeter internal
memory to the output buffer and retrieve them with
the co m p u t er.
measurement.
Loop
SPOLL - read the multimeter 's status byte until bit 4 (MAV) goes
high to indicate there is a message availab le in the output buffer.
End Loop
** NOTE: If
measurements complete.
TRIG:COUN is too big, FETC? can timeout before
FETC? expects a response before the timeout
interval specif ied in the program code. Using the previous program
detecting the OPC bit is recommended.
Retrieve the
CALC:AVER:AVER?
CALC:AVER:MAX?
CALC:AVER:M IN?
AVERage math operation response from the multimeter.
Retrieve the ave rage measurement value.
Retrieve the maxi mum measurement value.
Retrieve the minimum measurement value .
Check the multimeter for system errors.
SYST:ERR?
Retrieve the system error response from the
multimeter.
62 Agilent E1412A Multimeter Application Information
Chapter 2
LIMITTST
Source Code File
This program has the multimeter making measurements continuously until
an upper or lower limit is exceeded. The lower test limit is set to 2V; the
upper test lim it is set to 8V. Questionable Data Register bits 11 and 12 are
unmasked to allow the LO a nd HI Limit Test Failures to set the QUE bit in
the status byte. An input less the 2V or greater than 8V will report a test
failure and halt the progra m.
**** Set up the Multimeter ****
*RST
*CLS
CONF:VOLT 10
CALC:STAT ON
CALC:LIM:LOW 2
CALC:LIM:UPP 8
CALC:FUNC LIM
STAT:QUES:ENAB 6144
Reset the multimeter.
Clear the multimeter's st a tus registers.
Configure for dc volts, 10V range.
Enable the math fun ction.
Set lower limi t to 2.
Set upper limit to 8.
Select a math function; set to LIMit.
Unmask the limit error bits.
Loop
READ?
Trigger measur ement and place response into the
output buffer.
Enter re sponse into the computer.
SPOLL - read the multimeter's status byte until bit 3 (QUE) goes
high to indicate there is a Limit Test Failure (HI or LO).
Wait 1 second.
End Loop
Check the multimeter for system errors.
SYST:ERR?
Retrieve the system error response from the
multimeter.
Chapter 2
Agilent E1412A Multimeter Application Information 63
VEE Programming
Example
VEE is Agilent's Visual Engineering Environme nt, a graphical
programming language for creating test systems and solving engineering
problems. This section provides an instrument control example using the
“Direct I/O” feature of VEE. Direct I/O allows you to directly specify
messages to be sent t o an instrument and to directly r ead the information sent
back by an instru me n t. Dire ct I/O also o ffer s the mo st eff icie n t I/O
performance in VEE.
The example provided here synchronizes a measurement scan with a switch
module. This is the sam e exampl e previo usly disc ussed in this chapt er with
programs provided in the C and Visual Basic pro gramming languages.
Device Configuration You must configure your E1412A Multimeter (and the switch module)
before you can communicate with them.
1. Select I/O
Selec t or Configure
2. Select the
select
selection pops up the
3. Fill in the
Timeout.
select
pops up.
4. Verify
others).
5. Select
boxes.
6. Select the “name” you put in the name field of the device
configuration dialog box now appearing in the instrument list and
press the Get Instr button.
⇒ Instrument... from the menu bar. The Instrument
dialog box pops up.
Direct I/O button from the Instrument Type choices. Then
Add In stru ment from the Instrument Configure choi ces. This
Device Configuration dialog box.
Device Configuration Name, Interface, Address and
Set Byte Ordering to MSB and Live Mode to ON. Then
Direct I/O Config... The Direct I/O Configuration dialog box
Conformance is set to IEEE 488 (use default settings for all
OK to close both the Direct I/O and Devi ce Conf iguration
64 Agilent E1412A Multimeter Application Information
Chapter 2
Program Description The instruments are programmed using Direct I/O objects connected as
required by the sequ ence of SCPI commands. Readi ng of the E1476A status
byte is performed using the
SPOLL whose action is set to
I/O | Advanced I/O | Device Event object
ANY SET and its m ask s et to #H80. This mask
allows reading only the OPR bit of the statu s byte (bit 7) which gets set by
bit 8 (Scan Com ple te ) from the Operation St atu s Regist er when the swi tc h
module completes the scan list. Following the detection of scan complete,
the readings are retrieved wi th the Multi meter's
in an array format to a VEE
Measurements
. The readings are also sent to a Strip Chart Display object
AlphaNumeric Display object titled E1412A
FETCh? command and sent
which gives a plot of the measurements.
Strip Chart Object In parallel with the E1412A Measurements AlphaNumeric Display object
is a
Strip Chart Display object that displ ays the readings of the eight
channels. The
the horizontal and ve rtical axis to best display the measured data . Upper and
lower boundary traces could be added to the strip chart's display.
Strip C h ar t has an Auto Scale button to automati cally scale
Chapter 2
Agilent E1412A Multimeter Application Information 65
See your VEE documentation and on-line hel p for more deta il on test and
measurement I/O control . If you are not using VEE and are curious about the
graphical programming language, call your local Agilent sa les office for
more information. You can get a free VEE Evaluation Kit containing
detailed te chnical in formation and a demo di sk that wa lks you through many
of VEE's features an d functions. The following br ochures provide additiona l
information about VEE:
• VEE Visual Enginee ring Environment
• VEE The Most Productive Language for Test and Measurement
• VEE Visual Enginee ring Environment Technical Data
66 Agilent E1412A Multimeter Application Information
Chapter 2
Multimeter Command Reference
Using This Chapter
This chapter describe s the Sta ndard Commands for Programmable Instruments
(SCPI) and IEEE 488.2 Common (*) Commands applicable to the E1412A 6½-Digit
Multimeter.
Command Types
Commands are separated int o two types: IEEE 488.2 Common Commands and SCPI
Commands.
Chapter 3
Common
Command
Format
SCPI
Command
Format
The IEEE 488.2 s tanda rd de fines th e Com mon comma nds th at per form f unctio ns li ke
reset, self-test, status byte query, etc. Common commands are four or five characters
in length, always begin with the asterisk character (*), and may include one or m o re
parameters. The command keyword is separated from the first parameter by a space
character. Some examples of common commands are shown below:
*RST *ESR 32 *STB?
The SCPI commands perform functions such as making measurements, querying
instrument states, or retrieving data. The SCPI commands are grouped into command
“subsystem structures”. A command subsystem structure is a hierarchical structure
that usually consists of a top level (or root) command, one or more low-level
commands, and their parameters. The following example shows the root command
CALibration
CALibration
and its lower-level subsystem commands:
:COUNt?
:LFRequency 50|60|MIN|M AX
:LFRequency? [MIN|MAX]
:SECure:CODE <
:SECure:STATe OFF|ON, <
:SECure:STATe?
:STRing <
:STRing?
:VALue <
:VALue?
:ZERO:AUTO ON|OFF
:ZERO:AUTO?
quoted string>
value>
new code>
code>
Chapter 3
CALibration
STRing, STRing?, VALue and VALue? are second level commands, and CODE,
STATe and STATe? are third level commands.
is the root command, COUNt?, LFRequency, LFRequency?, SECure ,
Multimeter Command Reference 67
Command
Separator
A colon (:) always separates one command from the next lower level command as
shown below:
CALibration:SECure:STATe?
Colons separate the root command from the second level command
(
CALibration:SECure) and the second level from the third level (SECure:STATe?).
Abbreviated
Commands
Implied
Commands
The command syntax shows most commands as a mixture of upper and lower case
letters. The uppe r case letter s indicate th e abbreviate d spelling for the command. For
shorter progra m lines, send the abbreviated f orm. For better program re adability, you
may send the ent ire co mm an d . Th e inst rument will accep t eit her the ab b re via te d
form or the entire comman d.
For exampl e, if the co mm an d syn tax sho ws
are both acceptable forms. Othe r forms of
MEASure, then MEAS and MEASURE
MEASure, such as MEASU or MEASUR
will generate a n error. Additionally, S CPI commands are case insensit ive. Therefore,
you may use uppe r or lower case letters and commands of the f orm
measure, and MeAsUrE are all acceptable.
MEASURE,
Implied commands a re those which appear in square brackets ([]) in the command
syntax. (Note that the brackets a re not par t of the command; do not se nd them to the
instrument.) Suppose you send a second level command but do not send the
preceding implie d command. In thi s case, the instrument assumes you intend to use
the implied command and it responds as if you had sent it. Examine the partial
[SENSe:] subsystem shown below:
[SENSe:]
FUNCtion “<
FUNCtion?
RESistance
:RANGe <
:RANGe? [MIN|MAX]
function>” (e.g., <function> = VOLT:AC)
range>|MIN |MAX
The root command SENSe is a n implied command. For exampl e, to set the multimeter's
function to AC volts, you can send either of the following command statements:
SENS:FUNC “VOLT:AC” or FUNC “VOLT:AC”
68 Multimeter Command Reference
Chapter 3
Parameters Parameter Types. The following table contains explanations and exampl es of
parameter types you might see lat er in this c hapter.
Parameter Type Explanations and Example s
Numeric Accepts all commonly used deci m al representations of number
including optional signs, decimal points, and scientific notation.
123, 123E2, -123, -1.23E2, .123, 1.23E-2, 1.23000E-01.
Spec ial cases include MINimum, MAXimum , and DEFault.
Boolean Represents a single binary condition that is either true or false.
ON, OFF, 1, 0
Discrete Selects from a finite number of values. These parameters use
mnemonics to represent each valid setting.
An example is t he TRIGger :SOURce <source> command where
source can be BUS, EXT, or IMM.
Optional Parameters. Parameters shown within square brackets ([]) are optional
parameters. (Note that the brackets are not part of the command; do not send them
to the instrument.) If you do not specify a value for an optional parameter, the
instrument chooses a default value. For example, conside r the
TRIGger:COUNt? [MIN|MAX] command. If you send the command without
specifying a
is returned. If you send the
trigger count allowa ble. If you send the
maximum trigger count allowable. Be sure to place a space between the command
and the parameter.
MINimum or MAXimum parameter, the present TRIGger:COUNt value
MIN parameter, the comma n d returns the mini m um
MAX param eter , th e com mand retur ns the
Linking
Commands
Linking IEEE 488.2 Common Commands with SCPI Commands. Use only a
semicolon between the commands. For example :
*RST;RES:NPLC 100 or SAMP :C OUNt 25;* WAI
Linking Multiple SCPI Commands From the Same Subsystem. Use only a
semicolon between commands withi n the same subsystem. For example, to set
trigger count , trigger delay and the t rigger sour ce which a re all set usi ng the
TRIGger
subsystem, send the following SCPI string:
TRIG:COUNt 10;DELay .05;SOURce TTLT4
Linking M ulti pl e SCP I Command s of Diff ere nt Subsystems . Use both a
semicolon and a colon between commands of different subsystems. For example, a
SAMPle and OUTPut command can be sent in the same SCPI stri ng linked with a
semicolon and colon (;:) as follows:
SAMP:COUNt 10;:OUTP:TTLT4 ON
Chapter 3
Multimeter Command Reference 69
Multimeter Range and Resolution Tables
The following tables lis t the voltage and resistance ranges availa ble for the
multimeter. Also shown are the associated resolution values versus aperture time in
seconds or integrati on time in power line cycles (PLCs) for each range.
Table 3-1. DC Voltage Resolution versus Integration Time or Aperture Time
Integratio n Tim e in Po wer Li ne Cycles (PLC s)
Apertu re Tim e fo r 60H z Li ne Frequency (seconds )
Maximum
Range
100mV 120mV 30nV 100nV 300nV 1µV10µV
1 V 1.2V 300 nV 1µV3µV10µV 100µV
10V 12V 3µV10µV30µV 100µV1mV
100 V 120V 30µV 100 µV300µV1mV10mV
300 V 300V 300µV 1 mV 3mV 10mV 100mV
Reading
100 PLCs
1.67s
10 PLCs
167 ms
1 PLC
16.7ms
0.2 PLC
3.33ms
0.02 PLC
0.333ms
Table 3-2. DC Current Resolution versus Inte gration Time or Aperture Time
Integratio n Tim e in Po wer Li ne Cycles (PLC s)
Apertu re Tim e fo r 60H z Li ne Frequency (seconds )
Maximum
Range
10 mA 12mA 3nA 10nA 30nA 100 nA 1µA
100mA 120mA 30nA 100nA 300nA 1µA10µA
1A 1.2A 3nA 1µA3µA10µA 100 µA
Reading
100 PLCs
1.67s
10 PLCs
167 ms
1 PLC
16.7ms
0.2 PLC
3.33ms
0.02 PLC
0.333ms
3 A 3A 900nA 3µA9µA30µA 300µA
70 Multimeter Command Reference
Chapter 3
Table 3-3. 2-W ire and 4-Wire Resistance Resolution versus Integration Time or Aperture T ime
Integratio n Tim e in Po wer Li ne Cycles (PLC s)
Apertu re Tim e fo r 60H z Li ne Frequency (seconds )
Maximum
Range
100Ω 120Ω 30µΩ 100µΩ 300µΩ 1mΩ 10mΩ
1kΩ 1.2 kΩ 300mΩ 1mΩ 3mΩ 10mΩ 100 m Ω
10kΩ 12kΩ 3mΩ 10mΩ 30mΩ 100 mΩ 1Ω
100 kΩ 120kΩ 30mΩ 100mΩ 300mΩ 1Ω 10Ω
1MΩ 1. 2MΩ 300mΩ 1Ω 3Ω 10Ω 100Ω
10 MΩ 12MΩ 3Ω 10Ω 30Ω 100Ω 1kΩ
100 MΩ 100MΩ 30Ω 100Ω 300Ω 1kΩ 10kΩ
Reading
100 PLCs
1.67s
10 PLCs
167 ms
1 PLC
16.7ms
0.2 PLC
3.33ms
0.02 PLC
0.333ms
Table 3-4. AC Voltage: Range versus Resolution
Resolution Choices versus Range
RANGE 100 mV 1 V 10V 100V 300V
MIN 100nV 1µV10µV 100µV1mV
power-on and
*RST setting
MAX 10µV 100µV 1mV 10mV 100 mV
1µV10µV100µV 1mV 10mV
Table 3-5. AC Current: Range versus Resolution
power-on and
*RST setting
SCPI Command Reference
This section describes the Standard Commands for Programmable Instruments
(SCPI) for the E1412 A 6½-Digit Multimeter. Commands ar e listed alphabeti cally by
subsystem and also within each subsystem.
Resolution Choices versus Range
RANGE 1A 3A
MIN 1µA3µA
10 µA30µA
MAX 100 µA 300µA
Chapter 3
Multimeter Command Reference 71
The ABORt command subsystem removes the multimeter from the wait-for-trigger
state and places it in the idle state.
is
TRIGger:SOURce BUS.
Subsystem Syntax ABORt
Example Aborting a Measurement
ABORt
ABORt is only effective when the trigger source
CONF:VOLT:DC
TRIG:SOUR BUS
INIT
ABOR
Function: DC voltage.
Trigger source is BUS trigger.
Place multimeter in wait-for-trigger state.
Abort waiting for a trigger and place
multimeter in idle state.
Comments • ABORt does not affect any other settings of the trigger system. When the
INITiate command is sent, the trigger system will respond as it did before
ABORt was executed.
• ABORt returns the multimeter to the idle state for TRIGger:SOURce BUS. The
“Tri gger ignored” error is generated when a Group Execut e Tr i gger (GET) bus
command or
(which puts the multimeter into the idle state).
*TRG common command is execu t ed aft er an ABORt command
• Related Commands: INITiate, TRIGger
• *RST Condition: After a a *RST, the multimeter acts as though an ABORt has
occurred.
72 Multimeter Command Reference
Chapter 3
CALCulate
There are five math operati ons available (AVERage, DB, DBM, LIMit, and NULL), only
one can be enabled at a t ime. Each performs a mathematical operation on every readi ng
or stores data on a series of readings. The selected math operati on remains in effect
until you disable it, change functions, turn off the power, or perform a remote interface
reset. The math operatio ns use one or more internal registers . You can preset the values
in some of the registers, while others hold the results of the math operation.
The following table shows the math/m easurement function combinatio ns allowed.
Each “
X” indicates an allowa ble com bination . If you cho ose a math opera tion tha t i s
not allowed with the pr esent meas urement function, m ath is turne d off. I f you select
a valid math operation and then change to one that is invalid, a “Settings conflict”
error is generated over the remote interface. For null and dB measurements, you
must turn on the math operation before writing to the ir math registers.
Valid Math/Measurement Function Combinations
Measurements
DCV ACV DCI ACI Ω2W Ω4W Freq Per Ratio
AVERage XXXXXXXXX
DB XX
DBM XX
LIMit XXXXXXXXX
NULL XXXXXXXX
Subsystem Syntax CALCulate
:AVERage:AVERage?
:AVERage:COUNt?
:AVERage:MAXimum?
:AVERage:MINimum?
:DB:REFerence <
:DB:REFerence? [MIN|M AX]
:DBM:REFerence <
:DBM:REFerence? [MIN|MAX]
:FUNCtion AVERage|DB|DBM|L IMit|NULL
:FUNCtion?
:LIMit:LOWer <
:LIMit:LOWer? [MIN|MAX]
:LIMit:UPPer <
:LIMit:UPPer? [MIN|MAX]
:NULL:OFFSet <
:NULL:OFFSet? [MIN|MAX]
:STATe OFF|ON
:STATe?
value> |MIN|MAX
value> |MIN|M AX
value> |MIN|M AX
value> |MIN|MAX
value> |MIN|M AX
Chapter 3
Multimeter Command Reference 73
:AVERage:AVERage?
CALCulate:AVERage:AVERage? reads the averag e of all read i ng s taken s ince
AVERage was enabled (CALC:FUNC AVER and CALC:STAT ON commands). The
average value is cleared when
the multimeter is reset. The average value is stored in volatile memory.
Example Query the Average of All Readings Taken S ince the AVERage Math Operation
was Enabled
AVERage is enable d, when power is removed, or after
CALC:AVER:AVER?
:AVERage:COUNt?
CALCulate:AVERage:COUNt? reads the number of readings tak en sin ce
AVERage was enabled (CALC:FUNC AVER and CALC:STAT ON commands). The
count value is cleared when
CALC:STAT ON commands, when power has been off, or after a remote interface
reset. The number of readings taken is stored in volatile memory.
Example Query the Number of Readings Since the AVERage Math Operation was
Enabled
CALC:COUN?
:AVERage:MAXimum?
CALCulate:AVERage:MAXimum? reads the maximum value found from an
AVERage operation. The max value is cleared when AVERage is enabled
(
CALC:FUNC AVER and CALC:STAT ON commands), when power is removed, or
after the multimeter is reset . The maximum value is stored in volatile memory.
Query the average of all readings.
AVERage is enable d by the CALC:FUNC AVER and
Query number of readin gs.
Example Query the Maximum Value Found During an AVERage Math Operation
CALC:AVER:MAX?
:AVERage:MINimum?
CALCulate:AVERage:MINimum? reads the minimum value found from an
AVERage function operation. The min value is cleared when AVERage is enabled
(
CALC:FUNC AVER and CALC:STAT ON commands), when power is removed, or
after the multimeter is reset . The minimum value is stored in volatile memory.
Example Query the Minimum Value Found During an AVERage Math Operation
CALC:AVER:MIN?
74 Multimeter Command Reference
Query the max valu e.
Query the min valu e.
Chapter 3
:DB:REFerence
Example Set the DB Reference Value
CALCulate:DB:REFerence <value>|MIN|MAX stores a rela tive value in the dB
Relative R egister. Yo u mus t turn on the mat h o per a tion e. g ., exec ut e
CALC:STAT ON before writing to the math register. You can set the relativ e value
to any number between ±200dBm (the
MIN and MAX valu es). Th e dB ref ere n ce is
stored in volatile memory.
:DB:REFerence?
Example Query th e DB Reference Value Set for the DB Math Operation
:DBM:REFerence
CALC:STAT ON
CALC:DB:REF 60
CALC:FUNC DB
CALCulate:DB:REFerence? [MIN|MAX] queries dB reference value.
CALC:DB:REF?
CALCulate:DBM:REFerence <value>| MIN|MAX selects the dBm reference value.
Choose from:
900, 1000, 1200, or 8000 ohms. MIN = 50Ω. MAX = 8000Ω. You must turn on the
50, 75, 93, 110, 124, 125, 135, 150, 250, 300, 500, 600 (default), 800,
Turn on the math operation.
Sets DB re ference to 60 dBm.
Select the DB math operation. You can select
the calculate function at any time before or
after enabl ing the calculate state.
Query the DB reference value.
math operation e.g. , execute CALC: STAT ON before writing to the math regist er.
The dBm reference is stored in non-volatile memory.
Example Set the DBM Reference Value
:DBM:REFerence?
CALCulate:DBM:REFerence? [MIN|MAX] queries the dBm reference.
Example Query th e DBM R efe ren ce V a lue Set for the DBM Math Operation
Chapter 3
CALC:STAT ON Turn on the math operation.
CALC:DBM:REF 135 Sets DBM reference value to 135.
CALC:FUNC DBM
CALC:DBM:REF? Query the DBM reference value.
Select the DBM math operat ion. You can s elect
the calculate function at any time before or
after enabl ing the calculate state.
Multimeter Command Reference 75
:FUNCtion
CALCulate:FUNCtion AVERage|DB|DBM|LIMit|NULL selects the math function
to be used. One function is enabled at a time with
function MUST be enabled with
CALC:STATe ON.
NULL the default. The selected
Parameter
Summary
• AVERage measurements st ore the minimum and maximum readings from a
number of measurements. The multimeter records the number of readings
taken since the average function was enabled then calculates the average of all
the readings. You read these values with
AVERage? and COUNt?.
CALC:AVER:MIN?; MAX?;
• DB measurements are the difference between the input signal and a stored
relative value, with both values converted to dBm.
• DBM operations calculate the power delivered to a resistance referenced to
1 milliwatt.
• The LIMit parameter enables pass/ fail test ing on the upper a nd lower limits you
specify using the
LIMit:UPPer and LIMit:LOWer commands.
• NULL measurements (also called relative measurement s ) provi d e a readi ng
which is the differ ence between a stored null value and the input signal.
• See the section titled “Math Operatio ns” beginning on pag e 41, for more detail
on the
CALCulate operations.
Example Set the Calc ula te M ath Function to Ma ke Upp er and Lower Lim i t Tests o n
Each Measurement
CALC:FUNC LIM
CALC:LIM:LOWer
CALC:LIM:UPPer Set the upper limit to test against .
CALC:STATe ON Enable the limit math operation.
Set calculate function to limit.
Set the lower limit to test against.
:FUNCtion?
CALCulate:FUNCtion? queries the multimeter to determine the present math
function. Returns
Example Query the Calculate Math Function
CALC:FUNC?
76 Multimeter Command Reference
AVER, DB, DBM, LIM, or NULL.
Query the calculate function.
Chapter 3
:LIMit:LOWer
Example Set the Lower Limit
CALCulate:LIMit:LOWer <value>|MIN|MAX sets the lower limit for limit testing .
You can set the value to any number between 0 and ±120% of t he highest range , for
the present func tion.
MIN = –120% of th e highest r ange. MAX = 120% of the hi ghest
range. You must turn on the math operati on e.g., e xecute CALC:STAT ON before
writing to the math register. The lower limit is stored in volatile memory.
:LIMit:LOWer?
Example Query th e Low er Lim i t Set for the LIMit Math Operation
:LIMit:UPPer
CALC:STAT ON
CALC:LIM:LOW 1000
CALC:FUNC LIM
CALCulate:LIMit:LOWer? [M IN| M AX ] queries the lower limit.
CALC:LIM:LOW?
CALCulate:LIMit:UPPer <value>|MIN|MAX sets the upper limit for limit testing.
Turn on the math operation.
Set the lower limit.
Select the LIMi t math operation. You ca n select
the calculate function at any time before or
after enabl ing the calculate st ate.
Query th e lo w er li m i t.
You can set the value to any number between 0 and ±120% of the highest range, for
the present func tion.
MIN = –120% of the highest range. MAX = 120% of the highest
range. You must turn on the math operati on e.g., e xecute CALC:STAT ON before
writing to the math register. The upper limit is stored in volatile memory.
Example Set the Upp er Lim i t
:LIMit:UPPer?
Example Query the Upper Limit Set for the LIMit Math Operation
Chapter 3
CALC:STAT ON Turn on the math operation.
CALC:LIM:UPP 3000 Set the upper limit.
CALC:FUNC LIM
CALCulate:LIMit:UPPer? [MIN|MAX] queries the upper limit.
CALC:LIM:UPP? Queries the upper limit.
Select the LIMi t math operation. You ca n select
the calculate function at any time before or
after enabl ing the calculate st ate.
Multimeter Command Reference 77
:NULL:OFFSet
Example Set the Null Offset Value
CALCulate:NULL:OFFSet <value>|MIN|MAX stores a null value in the
multimeter's Null Regis ter. You must turn on the math operation e.g., execute
CALC:STAT ON before writing to the math register. You can set th e null va lue to
any number between 0 and ±120% of the highest range, for the present function.
MIN = –120% of the highest range. MAX = 120% of the highest range. The null value
is stored in volatile memory. See the secti on titled “Math Operations - NULL
Function” beginning on page 41 for another way to store the offset value.
:NULL:OFFSet?
Example Query th e Nul l Offs et V alu e Set for th e NUL L Math Operation
:STATe
Example Enable the Currently Selected Calculate Math Function
CALC:FUNC NULL
CALC:STAT ON
CALC:NULL:OFFS 500
CALCulate:NULL:OFFSet? [MIN|MAX] queries the null value.
CALC:NULL:OFFS?
CALCulate:STATe OFF|ON disables or enables the selected math function. The
Set math funct io n to NULL. You may c hoose t o
set the math function after setting STATe ON.
Turn on math operati on.
Set null offse t to 500.
Query the null offset value.
state is stored in volatile memory.
CALC:STAT ON
The selec ted or default math function is
enabled.
:STATe?
CALCulate:STATe? queries the state of the math function. Returns “0” (OFF) or
“
1” (ON).
Example Query Whether a Math Function State is On or Off
CALC:STAT?
78 Multimeter Command Reference
Query the state.
Chapter 3
The CALibration command subsystem allows y ou to enter a security code to prevent
accidental or unauthorized calibrations of the multimeter. When you first receive your
multimeter, it is secured. You must unsecure it by entering the correct security code
before you can calibrate the multimeter (see
Subsystem Syntax CALibration
:COUNt?
:LFRequency 50|60|400
:LFRequency? [MIN|MAX]
:SECure:CODE <
:SECure:STATe OFF|ON,<
:SECure:STATe?
:STRing <
:STRing?
:VALue <
:VALue?
:ZERO:AUTO ON|OFF
:ZERO:AUTO?
:COUNt?
CALibration
CALibration:SECure:STATe command).
new code>
code>
quoted string>
cal_value>
Comments • *RST does not change the calibration count stored in non-volatile memory.
Example Query the Number of Occurrences of Point Calibrations
:LFRequency
Comments • The wrong line frequency setting will cause reading errors to occur.
CALibration:COUNt? queries the multimeter to determine the number of times a
point calibrati on has occurred. A complete calibration of the multimeter increases
the count by the number of points calibr at ed. It is not a record of complete
calibrations . The count is stored in non-volatile memory.
CAL:COUN?
CALibration:LFRequency 50 |60|400 sets the line frequency to either 50Hz or
60 Hz .
Query the calibration count.
• You must execute the CAL:LFR command with a parameter of 50 or 400 to
change the line frequency setting to 50Hz. Specifying 400Hz sets line
frequency to 50Hz since 400 is an even multiple of 50.
• Default Setti ng : 60Hz
Chapter 3
• *RST does not change the line frequency setting.
Example Set the Line Frequency to 50Hz
CAL:LFR 50
Change the line frequency.
Multimeter Command Reference 79
:LFRequency?
Comments This command return s +50 for line frequency set to 400 because 400 is an even
Example Query th e Line F req uency Setting
CALibration:LFRequency? queries the line frequency setting.
multiple of 50.
:SECure:CODE
Comments • The security co d e is set to “HP_ E 1412” for C-size when the mu ltime te r is
Example Enter a New Calibration Security Code
CAL:LFR?
CALibration:SECure:CODE <new code> enters a new calibration securi ty code.
To change the securit y code, first unsecur e the multimeter using the old security code
with
CAL:SEC:STAT OFF, <old code>. Then, enter the new co de. The calibration
security code may contai n up to 12 cha racte rs . Th e secu ri ty cod e is stored in
non-v olatile memory.
shipped from the factory. The security code is stored in non-volati le memory,
and does not change when power has been off or after a remote interface reset.
Query the line frequency.
• The security code <new code> can contain up to 12 alphanumeric characters.
The first chara cter mu s t be a lette r. The remaini ng characters can be le tter s or
numbers or an undersco re. You do not have to use all 12 c haracte rs but the f irst
character must be a letter.
• If you forget or lose the active security code, you can disable the security
feature by adding a jum per inside the multimeter (see Chapter 5 in the Servic e
Manual). You then enter a new code and remove the jumper.
CAL:SEC:STAT OFF, HP_E1412
CAL:SEC:CODE
80 Multimeter Command Reference
the_new_code
Unsecure with the old code.
Enter a new calibration code
(a maximum of 12 characters) .
Chapter 3
:SECure:STATe
Parameters
CALibration:SECure:STATe OFF|ON, <code> unsecures or secu re s the
multimeter for calibration. The calibration code must be the code set by the
CAL:SEC:CODE command. The state is stored in non-volatile memory.
Parameter Name Parameter Type Range of Values Default Units
OFF|ON boolean OFF | 0 | ON | 1 none
Comments • You can substitute decimal values for the OFF (“0”) and ON (“1”) parameters.
Example Set the Calib ra ti on Sta te to Uns ec ured
:SECure:STATe?
Example Query the Calibration Security State
<code>
discrete up to 12 characters
set by CAL:SEC:CODE
none
• The multimeter calibration is secured when shipped from the factory. The
security code is set to “
HP_E1412”.
• *RST does not change the state.
CAL:SEC:STAT OFF, HP_E1412
CALibration:SECure:STATe? returns a “1” or “0” to show whether the calibrat ion
security state is enabled (
CAL:SEC:STAT?
enter statement
1) or disabled (0). The number is sent to the output buffer.
Unsecure multimeter calibration.
Query multimeter calibration secur ity state.
Enter value into computer.
:STRing
Parameters
Comments • The calibration message can contain up to 40 charac te rs.
Chapter 3
CALibration:STRing <quoted string> allows you to record calibration information
about your multimeter while
information such a s the last calibr ation date and/or the next calibra tion due date. The
calibration message can conta in up to 40 characte rs. Characters in excess of 40 are
truncated and no error is generated. The string is stored in non-volatile m emory.
Parameter Name Parameter Type Range of Values Default Units
quoted string>
<
CAL:SEC:STAT is OFF. For example, you can store
discrete alphanumeric none
• Calibration security state must be OFF to store a string.
• The calibration message is stored in non-volatile memory and does not change
when power has been off or after a remote interface reset.
Multimeter Command Reference 81
Example Enter Calibration Information to Record the Next Calibration Date
:STRing?
:VALue
Parameters
CAL:STR 'Cal 4/4/YY, Due 10/4/YY'
CALibration:STRing? queries the calibration message and ret urns a quoted string
(or a null string “ ” if nothing is present).
Example Query the Calibration Message
CAL:STR?
enter statement
CALibration:VALue <cal_value > specifies the value of the known calibr ation
signal used by the calibration procedure. See the E1412A Service Manual, Chapter
5 “Adjustments”, for a more detailed description of the multimeter's
calibration/adjustment procedures.
Parameter Name Parameter Type Range of Values Default Units
Enter a calibration message to record the cal
date of April 4 and next cal due date as
October 4 (YY = year of due date).
Query the calibration message.
Enter value into computer.
:VALue?
cal_value>
<
numeric See the service manual none
Comment • *RST does not affect the calibration value.
Example Enter the Known Value for the Calibration Source Signal
CAL:VAL 10.0
CALibration:VALue? queries the present calibration value.
Enter calibration value.
Example Query the Calibration Value
CAL:VAL?
enter statement
Query the calibration value.
Enter value into computer.
82 Multimeter Command Reference
Chapter 3
:ZERO:AUTO
Parameters
CALibrate:ZERO:AUTO <mode> enables or disables the autozero mode. Autozero
applies to dc volta ge, dc current and 2-wire ohms measurements only. 4-wire ohms
and dc voltage ratio measuremen ts aut o ma tica l ly en abl e the aut o zer o m ode .
Paramete r N ame Parameter Type Range of Values Default Units
Comments • You can use “0” for OFF and “1” for ON in the mode parameter.
:ZERO:AUTO?
<mode>
boolean OFF |0|ON|1|ONCE none
• The ON parameter enables autozero. This is the default parameter which
causes the multimeter to inte rnally disconnect the input signa l following each
measurement and make a zero measurement. The zero reading is subtracted
from the input signal readi ng to preve nt offset voltages present on the
multimeter's input circuitry from affec ting measurement accuracy.
• The OFF parameter disa bles autozero. In this mode the multimete r take s one
zero measurement and subtracts it from all subsequent input signal
measurements prior to a change in function, range or integration time. A new
zero measurement is made following a change in func tion, range or integr ation
time. This mode increases mea surement speed be caus e a zer o me as urement is
not made for each input signal measurement.
• Autozero ONCE issues an immediate zero measurement and can be used to get
an update on the zero measurement for a specific input signal measurement.
This helps to increase measurement speed since you update the zero reading
without making zero measuremen ts for ever y measurement.
• *RST Condition: CALibrate:ZERO:AUTO ON (autozero enabled)
Chapter 3
CALibrate:ZERO:AUTO? quer ies the autoz ero mod e. Ret ur ns “0” (OFF or ONCE)
or “
1” ON.
Multimeter Command Reference 83
CALibration?
CALibration? perfor ms a calibration usi ng the specif ied calibrati on value set by the
CALibration:VALue command and queries the calibration response to verify a
successful cali bration.
Comments • Execution of this command begins the electr onic adjustment for the function
and range the multimeter is set to. The adju stment is performed based on the
value s t at ed in the
the input terminals.
• The command returns “0” to indicate there are no calibration errors and the
calibration was performed. A “
calibration is unable to be perfor med. The error message is reported to the
output buffer.
• You must set CALibration:SECure:STATe OFF <code> to allow a calibration
to be performed. This requires that you know the calibration secure code. The
secure state enabled prevents unauthorized calibration of the multimeter.
Example Calibrate the Active Function and Range Using the CAL:VALue
CAL:VAL command and the multimet er expect s that value at
1” is returned if a calibration error occurs and a
CAL?
monitor the status byte to detect calibration operation complete
enter statement
Perform the calibration .
Enter cal res ponse into computer to verify the
calibration was successful.
84 Multimeter Command Reference
Chapter 3
CONFigure
The CONFigure command subsystem configures the multimete r to perfor m the
specified measurement with the given range and resolution.
make the measurement after setting the configuration. Execu ting
equivalent to setti ng the multimeter configuration as follows:
Command Setting
RANGe As specified (or AUTO).
RESolution As specified, or as a functi on of ra nge, integration
time, or NPLCs.
CONFigure does not
CONFigure is
AC filter
([SENSe:]DET:BAND)
Autozero
([SENSe:]ZERO:AUTO)
Input resistance
([SENSe:]INP:IMP:AUTO)
Samples per trigger
(SAMP:COUN)
Trigger count
(TRIG:COUN)
Trigger delay
(TRIG:DEL)
Trigger source
(TRIG:SOUR)
VM Complete routing
(OUTP:TTLT<
Math function
(CALCulate:STATe)
n>:STAT)
After configur ing the multi mete r, use the
20 Hz - 300 kHz (medium filter)
OFF if resolution setting results in NPLC <1;
ON if reso lu ti o n s et tin g re s ul ts in NPL C ≥1
Applies to dc voltage and is disabled for all other
functions. 10MΩ for all dc volt age ranges.
1 sample
1 trigger
AUTO (Automatic del ay)
IMM (trigger signal is always true)
OFF (all trigger lines;
OFF
n = 0 - 7)
INITiate command to place the multimeter
in the wait-for-trigger state and store readings in the multimeter's internal memory.
Or, use the
READ? command to make the m easurement a nd send the r eadi ngs to the
output buffer when the trigge r is rece ived.
Subsystem Syntax CONFigure
:CURRent:AC [<range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
:CURRent[:DC] [<
:FREQuency [<
:FRESistance [<
:PERiod [<
:RESistance [<
:VOLTage:AC [<
[:VOLTage[:DC]] [<
[:VOLTage[:DC]]:RATio [<
The CONFigure command RANGe and RESolution parameters are optional. You
will get the default range and resol ution settings if you do not specify a range or
resolution i n the command. Yo u will get th ese default s ettings ev en if you set a range
Chapter 3
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
range>|MIN|MAX|DEF|AUTO[,<resolution>|MIN|MAX|DEF]]
Multimeter Command Reference 85
or resolution diffe rent from the default value prior to executing the CONFigure
command. The following table lists the default settings you can expect from the
CONFigure comma nd fo r eac h funct i on.
Default Settings for
FUNCTION RANGE RESOLUTION
CURR[:DC] 1A 1 µA
CURR:AC 1A 10µA
FREQ FREQ:RANG = 3Hz
FRES 1 kΩ 1mΩ
PER PER:RANG = 0.333 sec
RES 1kΩ 1mΩ
VOLT[:DC] 10V 10µV
VOLT[:DC]:RAT 10V 10µV
VOLT:AC 10 V 100µV
CONFigure Command by F un cti on
30µHz
VOLT:RANG = 10V
3.33µseconds
VOLT:RANG = 10V
86 Multimeter Command Reference
Chapter 3
:CURRent:AC
Parameters
CONFigure:CURRent:AC [<range>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] selects the AC current function and allows you to
specify the measurement range and re solution. See the range ve rsus resol ution table
at the beginning of this chapter for valid resolution choices f or each ac current range.
Parameter Name Parameter Type Range of Val ues Default Units
range>
<
<
resolution>
numeric 1 A|3A|
MIN|MAX|DEF|AUTO
numeric
resolution |
| MIN | MAX | DEF
A
A
Comments • To select a standard measurem en t ran g e, specify range as the input signal's
maximum expected current. The multimeter then selects the correct range that
will accept the input.
• The AUTO or DEFault option for the range parameter enables autorange.
• The MIN and MAX parameters select the minimum or maximum values for
range and resolution:
For range:
MIN = 1A; MAX = 3A
For resolution: MIN selects the best resolution (the smallest value) for the
selected rang e.
MAX selects the worst resolution (the largest value) for the
selected range. See Table 3-5 on page 71 for resolution choices.
• To select autorange, specify DEF for range or do not specify a value for the
range and resolution par ameters (see next bullet comment). In the autora nge
mode, the multimeter samples the input signal before each measurement and
selects the appropriate range.
• To specify the MIN or MAX resolution while autorangi ng, you must specify the
AUTO or DEF parameter fo r ran ge an d spec if y MIN or MAX e.g.,
CONF:CURR:AC DEF,MIN or CONF:CURR:AC DEF,MAX or
CONF:CURR:AC AUTO,MIN or CONF:CURR:AC AUTO,MAX (you cannot
omit the range parameter
resolution from being interpreted as a range setting.
DEF or AUTO). This prevents the MIN or MAX
Chapter 3
Example Making AC Current Measurements
CONF:CURR:AC 3,MAX
SAMP:COUN 3
READ?
enter statement
Function: dc current; range selected: 3A;
MAX resolution: 0.3 mA.
Take 3 readings; trigger source is IMMediate
by default.
Place multimeter in wait-for-t ri gger state and
make measurements; se nd readings to output
buffer.
Enter readings into computer.
Multimeter Command Reference 87
:CURRent[:DC]
Parameters
CONFigure:CURRent[:DC] [<range>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] selects the DC current function and allows you to
specify the measurement range and resolution.
Parameter Name Parameter Type Range of Val ues Default Units
range>
<
<
resolution>
numeric 10mA|100mA|1 A |3 A|
MIN|MAX|DEF|AUTO
numeric
resolution |
MIN| MAX|DEF
A
A
Comments • To select a standard measurem en t ran g e, specify range as the input signal's
maximum ex pected current . The multi m et er the n sel ect s the co rre ct rang e to
accept that input.
• The AUTO option for the range parameter enables autorange and will not
accept a resolution parameter but will default the integration time to 10 PLC.
• The DEFault option for the range parameter will also enable autorange.
The
DEF option for the resolution parameter defaults the integrat ion time to
10 PLC.
• The MIN and MAX parameters select the minimum or maximum values for
range and resolution:
For range:
MIN = 10 mA; MAX = 3A
For resolution: See Table 3-1 on page 70 for valid resolution choices for
each range.
• To select autorange, specify AUTO or DEF for range or do not specify a value
for the range and resolution parameters (see next bullet comment). In the
autorange mode, the multimeter samples the input signal before each
measurem ent an d select s the app rop ri ate ran g e.
• To specify the MIN or MAX resolution while autorangi ng, you must specify the
AUTO or DEF parameter fo r ran ge an d spec if y MIN or MAX
e.g.,
CONF:CURR:DC DEF,MIN or CONF:CURR:DC DEF,MAX or
CONF:CURR AUTO,MIN or CONF:CURR AU TO,MAX (you cannot omit the
range parameter
from being interpret ed as a range set ting.
Example Making DC Current Measurements
CONF:CURR 3,MAX
SAMP:COUN 3
READ?
enter statement
88 Multimeter Command Reference
DEF or AUTO). This prevents the MIN or MAX resolution
Function: dc current; range selected: 3A;
MAX resolution: 0.3mA.
Take 3 readings; trigger source is IMMediate
by default.
Place multimeter in wait-for-t ri gger state and
make measurements; se nd readings to output
buffer.
Enter readings into computer.
Chapter 3
:FREQuency
Parameters
CONFigure:FREQuency [<range>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] selects the frequency function.
Parameter Name Parameter Type Range of V alues Default Units
<range>
<resolution>
numeric 3E+00 Hz
numeric 3E-04 | 3E-05 | 3E-06 Hz
Comments • The frequency function uses one “range” for all inputs between 3Hz and
300kHz. A frequency measurement returns “
0” if no input is applied.
• Range and resolution settings are liste d below for the MIN, MAX, DEF and
AUTO parameters and the settings after a module reset (*RST).
PARAMETER RANGE RESOLUTION
MIN 3E+00 3E+06
MAX 3E +00 3E +04
DEF |AUTO
reset (*RST)
and module
3E +00 3E +05
Chapter 3
Multimeter Command Reference 89
:FRESistance
Parameters
CONFigure:FRESistance [<range>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] selects the 4-wire ohms function and allows you to
specify the measurement range and resolution.
Parameter Name Para m eter Type Range of Values Default Units
range>
<
<
resolution>
numeric 100Ω|1kΩ| 10kΩ|100kΩ|1MΩ
| 10MΩ|100MΩ|
MIN| MAX|DEF| AUTO
numeric
resolution|MIN|MAX|DEF
ohms
ohms
Comments • To select a standard measurem en t ran g e, specify range as the input signal's
maximum expected resistance. The multimeter then selects the correct range
that will accept the input.
• The AUTO or DEFault option for the range parameter enables autorange. The
DEFault option for resolution defaults the integration time to 10 PLC.
• The MIN and MAX parameters select the minimum or maximum values for
range and resolution:
For range:
MIN = 100Ω; MAX =100MΩ
For resolution: MIN selects the best resolution (the smallest value) for the
selected rang e.
MAX selects the worst resolution (the largest value) for the
selected rang e.
• To select autorange, specify DEF for range or do not specify a value for the
range and resolution parameters. In the autorange mode, the multimeter
samples the input signal be fore each measurement and selects the appropriate
range.
• To specify a MIN or MAX resolution while autoranging, you must
specify the
CONF:FRES DEF,MAX or CONF:FRES AUTO,MIN or
CONF:FRES AUTO,MAX (you cannot omit the range parameter). This
prevents the
AUTO or DEFault parameter; CONF:FRES DEF,MIN or
MIN or MAX resolution from being interpreted as a range setting.
• Related Commands: FETCh?, INITiate, READ?
Example Makin g 4-W ir e Oh m s Me asu rements
CONF:FRES 1500,MAX
SAMP:COUN 3
READ?
enter statement
90 Multimeter Command Reference
Function: 4-wire ohms; range selected: 10kΩ;
MAX resolution: 1Ω.
Take 3 readings; trigger source is IMMediate
by default.
Place multimeter in wait-for-t ri gger state and
make measurements; se nd readings to output
buffer.
Enter readings into computer.
Chapter 3
:PERiod
Parameters
CONFigure:PERiod [< range>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] s elects the period functio n and allows you to specify
range and resolution.
Parameter Name Parameter Type Range of V alues Default Units
<range>
<resolution>
numeric 3.33E -01 Sec
numeric 3.33E-05| 3.33E-06 | 3.33E-07 Sec
Comments • The period function uses one “range” for al l inputs between 0.33 seconds and
3.3µSec. A period measurement will return “
0” if no input is applied.
• Range and resolution settings are liste d below for the MIN, MAX, DEF and
AUTO parameters and the settings after a module reset (*RST).
PARAMETER RANGE RESOLUTION
MIN 3.33E-01 3.33E-07
MAX 3.33E-01 3.33E-05
DEF |AUTO
reset (*RST)
and module
3.33E-01 3.33E-06
Chapter 3
Multimeter Command Reference 91
:RESistance
Parameters
CONFigure:RESistance [<ran ge>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] selec ts the 2- wire ohms func tion and allows you to
specify the range and resolution.
Parameter Name Para m eter Type Range of Values Default Units
range>
<
<
resolution>
numeric 100Ω|1kΩ|10kΩ| 100kΩ|1MΩ|
10MΩ|100MΩ|
MIN|MAX|DEF|AUTO
numeric
resolution|MIN|MAX|DEF
ohms
ohms
Comments • To select a standard measurem en t ran g e, specify range as the input signal's
maximum expected resistance. The multimeter then selects the correct range
that will accept the input.
• The AUTO or DEFault option for the range parameter enables autorange. The
DEFault option for resolution defaults the integration time to 10 PLC.
• The MIN and MAX parameters select the minimum or maximum values for
range and resolution:
For range:
MIN = 100Ω; MAX =100MΩ
For resolution: MIN selects the best resolution (the smallest value) for the
selected rang e.
MAX selects the worst resolution (the largest value) for the
selected rang e.
• To select autorange, specify DEF for range or do not specify a value for the
range and resolution parameters. In the autorange mode, the multimeter
samples the input signal be fore each measurement and selects the appropriate
range.
• To specify a MIN or MAX resolution while autoranging, you must specify
AUTO or DEFault for range; CONF:RES DEF,MIN or CON F:RES DEF,MAX
or
CONF:RES AUTO,MIN or CONF:RES AUTO,MAX (you cannot omit the
range parameter). This prevents the
interpreted as a range setting.
MIN or MAX resolution from being
• Related Commands: FETCh?, INITiate, READ?
Example Makin g 2-W ir e Oh m s Me asu rements
CONF:RES 850,MAX
SAMP:COUN 3
INIT
FETC?
enter statement
92 Multimeter Command Reference
Function: 2-wire ohms; range selec ted: 1 kΩ;
MAX resolution: 0.1Ω.
Take 3 readings.
Place multimeter in wait-for-trigger state;
store readings in internal memory; trigger
source is IMMedia te by default.
Place readings in output buffer.
Enter readings into computer.
Chapter 3
:VOLTage:AC
Parameters
CONFigure:VOLTage:AC [<range>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] selects the AC-coupled RMS voltage funct ion a nd
allows you to specify the range and resolution.
Parameter Name Par ameter Type Range of Values Default Units
range>
<
<
resolution>
numeric 0.1V|1V|10V|100V|300V |
MIN|MAX|DEF|AUTO
numeric
resolution|MIN|MAX|DEF
volts
volts
Comments • To select a standard measurem en t ran g e, specify range as the input signal's
maximum expected vol tage. The multimeter then selects the correct range tha t
will accept the input.
• The AUTO or DEFault option for the range parameter enables autorange. The
DEFault option for resolution defaults the integration time to 10 PLC.
• The MIN and MAX parameters select the minimum or maximum values for
range:
For range:
MIN = 0.1V; MAX = 300V.
For resolution: See Table 3-4 on page 71 for valid resolution choices for
each range.
• To select autorange, specify AUTO or DEF for range or do not specify a value
for the range and resolut ion paramete rs. In the autorang e mode, the multi meter
samples the input signal be fore each measurement and selects the appropriate
range.
• To specify a MIN or MAX resolution while autoranging, you must specify
AUTO or DEFault for range; CONF:VOLT:AC DEF,MIN or
CONF:VOLT:AC DEF,MAX or CONF:VOLT:AC AUTO,MIN or
CONF:VOLT:AC AUTO,MAX (you cannot omit the range parameter). This
prevents the
MIN or MAX resolution from being interpreted as a range setting.
Chapter 3
Example Making AC Voltage Measu rements
CONF:VOLT:AC 0.54,MAX Function: AC volts; range selected: 1A;
SAMP:COUN 3
READ?
enter statement
MAX resolution: 100 µA.
Take 3 readings; source is IMMediate by
default.
Place multimeter in wait-for-t ri gger state and
make measurements; se nd readings to output
buffer.
Enter readings into computer.
Multimeter Command Reference 93
[:VOLTage[:DC]]
Parameters
CONFigure[:VOLTage[:DC]] [<range>|MIN|MAX|DEF|AUTO
[,<
resolution>|MIN|MAX|DEF]] selects the DC voltage function and allows you to
specify the range and resolution.
Parameter Name Parameter Type Range of V alues Default Units
range>
<
<
resolution>
numeric 100mV|1V|10V|100V|300V|
MIN| MAX|DEF| AUTO
numeric
resolution |MIN|MAX|DEF
volts
volts
Comments • To select a standard measurem en t ran g e, specify range as the input signal's
maximum expected voltage. The multimeter then selects the correct range to
accept the input.
• The AUTO or DEFault option for the range parameter enables autorange. The
DEFault option for resolution defaults the integration time to 10 PLC.
• The MIN and MAX parameters select the minimum or maximum value for
range and resolution:
For range:
For resolution:
selected rang e.
MIN = 100mV; MAX = 300V.
MIN selects the best resolution (the smallest val ue) for the
MAX selects the worst resolution (the largest value) for the
selected range. See Table 3-1 on page 70 for valid resolution choices for
each range.
• To sel ect autora nge, s pecify DEFault for range or do not spec ify a val ue for the
range and resolution parameters. In the autorange mode, the multimeter
samples the input signal be fore each measurement and selects the appropriate
range.
• To specify a MIN or MAX resolution while autoranging, you must specify
AUTO or DEFault for range; CONF:VOLT:DC DEF,MIN or
CONF:VOLT:DC DEF,MAX or CONF:VOLT:DC AUTO,MIN or
CONF:VOLT:DC AUTO,MAX (you cannot omit the range parameter). This
prevents the
MIN or MAX resolution from being interpreted as a range setting.
• Related Commands: FETCh?, INITiate, READ?
Example Making DC Voltage Measu rements
CONF:VOLT 0.825,MAX Function: DC voltage; range selected: 1A ;
SAMP:COUN 3
INIT Place multimeter in wait-for-trigger state;
FETC?
enter statement
94 Multimeter Command Reference
MAX resolution: 100 µA.
Take 3 readings.
store readings in internal memory; trigger
source is IMMedia te by default.
Place readings in output buffer.
Enter readings into computer.
Chapter 3
[:VOLTage[:DC]]:RATio
D
dc signal voltage
Hi and LO input
ut
--- -
CONFigure[:VOLTage[:DC]]:RATio [<range>|MIN|MAX|DEF|A UTO
[,<
resolution>|MIN|MAX|DEF]] conf igur es the multimeter for dc:dc ratio
measurements with the speci fied range and resolution.
C:DC RATIO =
------------------------------------------------ dc reference voltage
---------------------------------------------------
=
Sense HI and LO inp
The ratio is calculate d from the volta ge applied to the HI and LO input terminals
divided by the reference voltage applied to the “Sense” HI and LO terminals.
Autoranging is autom aticall y sele cted for the referenc e voltage measur ement on th e
“Sense” HI and LO terminals. The specified range in the command applies to the
signal connected to the HI and LO input terminals.
Note Autorange on the “Sense” terminals is from 100mV to 10V range only. Maximum
voltage you can apply to the “Sense” termi nals is 10V.
Parameters
Parameter Name Parameter Type Range of V alues Default Units
range>
<
(HI-LO input)
<
resolution>
numeric 100mV|1V|10V|100V|300V|
MIN| MAX|DEF| AUTO
numeric
resolution|MIN|MAX|DEF
volts
volts
Comments • To select a standard measurem en t ran g e, specify range as the input signal's
maximum expected voltage. The multimeter then selects the correct range to
accept the input.
• The AUTO or DEFault option for the range parameter enables autorange. The
DEFault option for resolution defaults the integration time to 10 PLC.
• The MIN and MAX parameters select the minimum or maximum values for
range and resolution:
For range:
For resolution:
selected rang e.
selected rang e.
MIN = 100mV; MAX = 300V.
MIN selects the best resolution (the smallest val ue) for the
MAX selects the worst resolution (the largest value) for the
Chapter 3
Multimeter Command Reference 95
The CONFigure? command querie s the multimeter to retur n the configuratio n set by
the most recent
It returns a quoted string to the output buffer in the following format:
Subsystem Syntax CONF igure?
Comments • When the multimeter is configured for current, voltage or resistance
measurements,
range and resolution. For example:
• If you sp ecify DEF, MIN, or MAX for the range or resolution parameters in
CONFigure or MEASure, the CONFigure? command returns the selected
value.
CONFigure?
CONFigure or MEASure command.
“<function> <parameter>,<parameter>”
CONFigure? returns the function followed by the selected
“CURR:AC +1.000000E+00,1.000000E-05”
“CURR +1.000000E+00,1.000000E-05”
“VOLT:AC +2.000000E+02,1.000000E-06”
“VOLT +3.000000E+02,1.000000E-06”
“FRES +100.0000E+03,1.000000E-05”
“RES +1.000000E+03,1.000000E-03”
“FREQ +3.000000+00,3.000000E-05”
“PER +3.333330E-01,3.333330E-06”
• Related Commands: CONFigure, MEASure
Example Queryin g th e M ulti m ete r C onfi guration
dimension string array Dimension computer array to store string.
CONF:FRES 900,MAX Function: 4-wire ohms ; range selected: 1kΩ;
CONF? Query configuration.
enter statement Enter string into comp u ter.
String Returned:
“FRES +1.000000E+003,9.999999E-02”
MAX resolution: 100mΩ.
96 Multimeter Command Reference
Chapter 3
The multimeter can store up to 512 readings in internal memory. The DATA
command allows you to determine how many readings are curre ntly stored.
Subsystem Syntax DATA
:POINts?
The INITiate command uses internal memory to store readings prior to a FETCh?
command e.g., when a measurement is initiated by the
query the number of stored readings in memory by sending the
command.
Comments • INITiate command uses internal memory to store readings prior to using a
FETCh? command. You use the DATA:POINts? command to query the
number of readings stored in internal memory to determine the amount of data
space to allocate on your computer to receive the data.
DATA
:POINts?
INITiate command. You can
DATA:POINts?
Chapter 3
Multimeter Command Reference 97
The FETCh? command retriev e s meas urements stored in the mo dule' s in te rnal
memory by the most recent
This command is most commonly used with
Subsystem Syntax FETCh?
Comments Execute INITiate before se nding the FETCh? command to place the multimeter in the
wait-for-trigger state. If the multimeter has not taken any data (i.e., if
not been executed), or if settings have been altered since the last
changing function or range ), the “Data corrupt or stale” error will be gener at ed.
Note If you do not alter settings, you could “FETCh?” the same data over and over again
without error.
• Readings sent to the output buffer ca n consist of two different lengths
(bytes or characters) in Real ASCII format:
FETCh?
INITiate command and places them in the output buffer.
CONFigure.
INITiate has
FETCh? (i.e.,
±1.23456E±12 LF or
±1.234567E±12
LF
• Each measurement is terminated with a Line Feed (LF). The GPIB
End-or-Identify (EOI) signal is sent with the last byte transferred. If multiple
measurements are returned, the measurements are separated by commas and
EOI is sent only with the last byte. For example:
±1.23456E±12 LF,±1.234567E±12 LF,±1.23456E±12 LF EOI
• The Multimeter's internal memory stores 512 rea dings maximum.
• Related Commands: CONFigure, INITiate, READ?
• *RST Con ditio n: Executing FETCh? after a *RST generates error “Data
corrupt or stale” (
Example Transfer ri ng Stored Readin gs to Out put Buffer
dimension array
CONF:VOLT:DC
SAMP:COUN 100
INIT
FETC?
enter statement
*RST places the mu ltimeter in the idle stat e).
Dimension computer array to store
100 readings.
Function: DC voltage.
100 readings per trigger.
Store readings in internal memory; trigger
source is IMMedia te by default.
Place readings in output buffer.
Enter readings into computer.
98 Multimeter Command Reference
Chapter 3
The INIT iate command subsystem places the multimeter in the wait-for -trigger sta te.
This command is most commonly used with
“Triggering the Mul timeter” beginning on page 45 for a complete de scription of the
E1412 trigger system which discusses the wait-for-trigge r state.
Subsystem Syntax INITiate
[:IMMediate]
[:IMMediate]
INITiate[:IMMediate] places the multimeter in the wait-for-trigger state. When a
trigger is receive d, r eadings are placed in multimeter inter nal memory.
Comments • After the trigger system is init iated using INITiate, use t h e TRIGger command
subsystem to control the behavior of the trigger system.
• If TRIGger:SOURce is IMMediate, the measurement starts and readings are
stored in internal memory as soon as
memory from previous commands are replac ed by the new readings.
INITiate
CONFigure. See the section titled
INITiate is executed. Readings stored in
• To transfer readings from memory to the output buffer, use the FETCh?
command.
• If TRIGger:SOURce is n ot IMMediate, the measurement starts as soon as a
trigger is receive d either from the external BNC connector, the VXIbus
backplane (
TTLT<n> trigger lines) or a BUS trigg er.
• The READ? command ex ec utes INITiate implicitly. The MEASure command
executes
output buffer, bypassing the multimeter's internal memory.
READ? implicitly. Executing READ? outputs data directly to the
• Related Commands: CONFigure, FETCh?, READ?
• *RST Con ditio n: *RST places the multimeter in the idle sta te.
Example Placing Multimeter in Wait-For-Trigge r State
CONF:VOLT:DC
TRIG:SOUR EXT
INIT
FETC?
INIT
Function: DC voltage.
Trigger source is the ex ternal BNC on the
multimeter.
Place multimeter in wait-for-trigger state;
store readings in internal memory when ext
trigger is received.
Place readings in output buffer.
You must re-initiate the wait-for-trigger state
after ea ch trigger cycle.
Chapter 3
Multimeter Command Reference 99
The INPut command enables or disables the aut omatic input impedance mode f or DC
voltage measurements.
Subsystem Syntax INPut
:IMPedance:AUTO
INPut:IMPedance:AUTO <mode> enables or disables the automatic input
impedance mode for DC voltage measurements. When disabled (
multimeter maintai ns its input impedance of 10MΩ for all DC voltage ranges. This
is useful to prevent a change in input impedance, caused by changing ranges, f rom
affecting th e mea sur ements.
Parameters
Parameter Name Parameter Type Range of V alues Default Units
INPut
:IMPedance:AUTO OFF|ON
:IMPedance:AUTO?
AUTO O FF), the
Example Enable Automat i c Input Imped ance ( use >10GΩ for 100mV, 1V and 10V ranges)
Comments • You can substitute decimal values for the OFF (“0”) and ON (“1”) parameters.
:IMPedance:AUTO?
INPut:IMPedance:AUTO? returns a number to show whether the automatic input
impedance mode is enabled or disabled: “
to the output buffer.
<mode>
mode (I m pedance)
Range for
Impedance
INP:IMP:AUT O ON Enable automatic input impedance.
boolean OFF|0|ON|1 None
AUTO OFF
(10MΩ)
all ranges 100mV, 1V and 10V
AUTO ON (>10GΩ)
(other ranges ar e at 10MΩ)
• *RST Con ditio ns: INP:IMP:AUTO OFF
1” = ON, “0” = OFF. The number is sent
Example Query the Input Impedance Mode
INP:IMP:AUT O ON
INP:IMP:AUT O?
enter statement
100 Multimeter Command Reference
Enable automati c input impedance.
Query multimeter to return input impe dance
mode (“1”).
Enter value into computer.
Chapter 3
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