Keithley 196 User manual

Model 196
System DMM
instruction Manual
Contains Operating and Servicing Information

WARRANTY
Keithley Instruments, Inc. warrants this product to be free from defects in material and tiorkmanship for a period of 1 year from date of
shipment.
Keithley Instruments, Inc. warrants the following items for90 days from the date of shipment: probes, cables, rechargeable batteries,
diskettes, and documentation.
During the warranty period, we will, at OUToption, either repair or replace any product that proves to be defective.~~ :
To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in Ct&e.land, Ohio. YOUwill
be given Prompt assistance and return instruciions. Send the product, transport&~ prepaid, to the indicated service facility. Repairs
will be made and the product returned, transportation prepaid. Repaired or replaced products are warranted for the balance of the origi-
nal warranty period, or at least POdays.
LIMITATION OF WARRANTY
This warranty does not apply to defects resulting from product modification without Keithley’s express written consent, or misuse of
any product or part. This warranty also does not apply to fuses,~software, non-rechargeable batteries, damage from battery leakage,~or
problems arising~55Zi-incmii~l wear or failure to follow instructions.
THIS WARRANTY IS IN LIEU OF ALL OTtiERWARRANTIES, EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED
WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. THE REMEDIES PRO\IIDED HEREIN ARE
BUYER’S SOLE AND EXCLUSIVE REMEDIES.
NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR ANY DIRECT, JNDI-
RECT, SPECIAL, INCIDENTALOR CONsE:QUENTIAL DAMAGES ARISING OUT OF THE USE OF ITS JNSTRIJM.ENTS AND
SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF
SUCH DAMAGES. SUCH EXCLUDED DAMAGES SHALL INCLUDE, BUT ARE NOT LIMITED To: COSTS OFTREMOVAL
AND INSTALLATION, Lossm SUSTAINED As THE RESULT OF IN3URY TO ANY PERSON, OR DAMAGETO PROPERTY.

Model 196~System DMM
Instruction Manual
01986, Keithley Instruments, Inc.
TestInstrumentation Group
All rights reserved.
Cleveland, Ohio, U.S.A.
Fourth PrintingJanuary 1992
Document Number: 196-901-01 Rev.0

SafetyPrecautions
The following safety precautions should be observed befoE
using this product and any associated inshvmentation. Al-
though some instruments and accessories would normally be
used with non-hazardousvoltages, therearesituatio~iis where
hazardous conditions may be present
This product is intended for use by qualiied personnel who
iecognize shock hazards and are familiar with the safety pre-
cautions required toavoid possible injury.Read the operating
information carefully before using the product.
Exercise extreme caution when a shock hazard is present. Le-
thal voittige may be present on cable connector jacks or test
f?xtures. The American National Standards Instih~te (ANSI)
states that a shock hazard exists when voltage levels greater
than 30V RMS, 42.4V peak, or 60VDC are present. A good
safety practice is to expect that hazardous voltage is present
in any unknown circuit before measuring.
Before operating an inskutient, make sure the line cord is
connected to a properly grounded power receptacle. Inspect
the connecting cables, test leads, and jumpers for possible
wear, cracks, or breaks before each use.
For maximum safety, do not touch theproduct, test cables, or
any other instruments while power is applied to the circuit
under test. ALWAYS remove power from the entire test sys-
tern and discharge any capacitors before: connecting or dis-
connecting cables or jumpers, installing or removing
switching cards, or making internal changes, such as install-
ing or removing jumpers.
Do not touch any object that could provide a current path to
the common side of the circuit under test or power lie
(earth) ground. Always make measurements with dry hands
while standing on a ~JY, insulated surface capable of with-
standing the voltage being measured.
Do not exceed the maximum signal levels of the instruments
and accessories, asdefined in thespecifications and operating
inform&ion, and a~shown on the instrument or test fixture
rear panel, or switchiig card.
Do not connect switching cards directly to unlimited power
circuits. They are intended to be used with impedance limit-
ed sources. NEVER cbnnect switching cards directly to AC
tin. When connecting sources to switching cards, install
$~~tive devices to lit fault current and voltage to the
card.
When fuses are used in a product, replace with same type and
rating for continued protection against fire hazard.
Chassis connections must only be used as shield connections
for measuring circuits, NOT as safety earth ground connec-
tions.
If you are using atest fxtwe, keep the lid closed while power
is applied tothe device under test.Safe operation requires the
u.s$of a lid interlock.
Ifa @saew ispresenton~hetest tixhm?,connectit tbsafety
earth ground using #18 AWG or larger wire.
The $ symbol on an instrument or accessory indicates that
1oOOVor more may be present on the terminals. Refer to the
product manual for detailed operahlnginformation.
Instrumentation and accessories should not be connected to
humans.
Maintenance should be performed by qualified service per-
sonnel. Before perfo&ng any maintenance, disconnect the
line cord~andall test cables.

SPECIFICATIONS
DC~VOLTS
6%Digits,
ANALOG SETTLING TIME: <lm.s (<2ms on 300mV range), to 0.01%
of step change. LINEARI’IYLinearity is defined as the timurn deviation from a straight
line between the readings at zero and full range: 1Oppm of range for
CMRR: >lZOdB at dc, MHz or 6OHz (iO.O5%) with lkQ in either lead. ~3V-3ooV ranges; 15ppm of range for 3OOmV range; at 23OC il°C.
NMRR: >M)dB at50Hz or60Hz (iO.0546). ~~ MAXIMUM ALLOWABLE INPUT: 300V rms. 425” peak, whichever is
less.
RESPONSE: Tiue root mean square, ac coupled.
CREST FACTOR (ratio of peak to rms)z Up to 3:l allowable.
NONSINUSOIDAL INPUTS: For fundamental frequencies < -, mest
factor ~3, add 0.25% of reading to specified accuracy for 3oomV and
3V ranges; add 0.6% of reading to specified accuracy for 30V and 3fXlV
ranges.
INPUT IMPEDANCE: lMlI shunted bv <12OoF.
3dBBANDWIDTHz 3WkHzfypical. ’ ’
MAXIMUM ALLOWABLE INPUT: 3oOV -, 425” peak, 10’ VHz,
whichever is less.
SETTLING TIME: 1 second to within 0.1% of change in reading.
TBMF’ERATURE COEFFICI@‘JT (0=18”C & 28Y?,*C):
< i(O.l x app!icable accuracy specification)K below 2OkHz,
f(0.2.x) for 2okHz to 1ook?iz.
CMRR: >6OdB at 5OHz or 6OHz (*0.05%) with IkR in either lead.
dB (Ref. = 1”): .4CC”RAcY *a
1 Year, IP-WC
INPUT *OHa-~0gz ?OW-?c! -. P??LUnoN
WNETGURATION: Automatic 2- or&,ire. Offset compensationavai!ab~e OBN CIRCUIT VOLTAGE: 5.5V maxinwm.
on 3wiXOkO ranges, requires proper zeroing. Allowable compensation
of ilOmV on 3OilQrange and ilWmV on 3ktl and 3OkO ranges. JJNEARIlY Linetity is defined as the madmum deviation from a &might
MAX, ALLOWABLE INPIJZ 3wV rms, 425V peak, whichever is less. line between the readings at zero and full range: 20ppm of range for SCO@3OkO ranges, at 23°C iYC.

3mA 10 n.4 0.05 + 10
3iE 1ooP.A
1d 0.050.05 ++~1010
3 A 10K.4 0.09 + 10 * v
‘4wigit counterror is 20. 3K-digit CO”“terror is 5.
MAXIMUMALLOWABLHINPUT: 3A, 250”.
OVERLOAD PROTECTION: 3A fuse (25OV), accessible from reii~ panel.
TEMPERATURE COEFFICIENT (O”-18’C & 2S”-500C):
c iCO.1 x applicable accumw svecification)PC. ~~~
1For Sinewaveinputs >x.m EOuntS.For 4Vdigit accuracy,divide cou*terror by
10..%3lidigit accuracy,counterrOIb 5. Jn 3vl- and4K.digit modes,specifica-
ti‘J”dapplyfor stnew.weinputs ,200Hz.
RESPONSE: True mot mean square, ac coupled.
CREST FACTOR (ratio of peak to rms): Up to 3:l allowable at % full scale.
NONSINUSOIDAL INPUTS: Spe&d accwacy for fundamental fquen-
ctes <lkJ&, CI& factor <3.
SEmING TIME: 1 second to within 0.1% of change in reading.
MAXIMUM ALLOWABLE INPUT: 3A, 250V.
OVERLOAD PROTECTION: 3A fuse (UOV) accessibl&fiom rear panel.
TEMPERATURE COEFFICIENT (O’-18’C & 28%d”Qi~ ~’
< f(O.l x applicable accuracy specification)i°C.
dB (Ref. = ImA): ‘4CC”RAcY *a
1 Year, 1S%B’C
INPUT 2oH51okHz RE8OLuTION ~~~~
-34 to +69 dB
(ZOJ4.4to 3.4) 0.2 0.01 dB
-54 to -34 dB
@!A to 20PA) 0.9 0.01 dB
tiAXIMUM READING RAT&
DCV, DCA, ACV, ACA READINGS/SECOND
conttn”ovs into Extemal Rigger into Triggered via
Internal Buffer I”temd Buffer IEEE488 Bus
IEEE-488 BUS IMPLEMENTATION
MULTILINE COMMANDS: DCL, LLO, SDC, GET, GTL; UNT, UNL,
.~- SPE, SPD.
UNILINE COMMANDS: IFC, REN,~EOI, SKQ, ATN.
INTERFACE FUNCTIONS: SHl. AHl, T6, TBO, L4, LEO, SRl, RLl, ?PO,
DCI. DTl, CO, El.
PROGRAMMABLE PARAMETERS: Range, Function, zero, Integration
Period, Filter. EOI. Trigger, Terminator, Delay, ?OO-Reading storage,
Calibration. Display, Multiplex, Status, Service Request, Self Test,
Output Format. TRANSLATOR.
GENERAL
RANGING: Manual or autoranging.
MAXIMUM READING: 3029999 counts in 6%.digit mode.
ZERO: Control subtract: on-scale value from subseqtient readings or allows
value to be prog&nmed.
CONNECTORS: Analog: Switch selectable front or rear, safety j&s.
Digital: TRIGGER input tid VOLTMETER COMPLETE &put on iear
panel, BNCs.
WARMUP: 2 hours to rated accuracy.
DISPLAY: 10, 0.5-in. alphanumeric LED digits with decimal point and
polarity. Function and IEEE-488 bus status also indicated.
ISOLATION: Input Lo to IEEE Lo orpower line ground: 5oOVpeak. 5~xlC+
max. VI+ product. >lO’D paralleled by 4OOpF.
DATA MEMORY: 1 to 500 locations, programmable. Measurement inter-
vals selectable from lms to 999999,&s or triggered.
BENCH READING RATE: 5 readings/second (2lsecond on 30M8 and
3COMtl ranges).
FILTER: Weighted average (exponential). Programmable weighting, 1 to
l/99.
OPERATING ENVIRONMENT: O”-500$ 0%.80% relative humidity up
to 35T; linearly derate 3% RH/“C, 35’C-5Ci’C (0%.60% RH up to 28OC
on 3oOMB range).
STORAGE ENVIRONMENT: -25” to +65OC.
POWER: 105.125V or 210.UOV, rex panel switch selected, 5OHz or 6OHz,
30VA max. YO-1lOV and 18022OV versions available upon request.
DIMENSIONS, WEIGHT: l27mm high x 216mm wide x 359mm deep
(5 in. x 8% in. x 14% in.). Net weight 3.7kg (8 Ibs.).
ACCBSSORIES AVAILABLE:
Model lOlYA-1: 5%.in. Single Fixed Rack Mounting Kit
Model lOlYA-2: 5’%-in. Dual Fixed Rack Mounting Kit
Model 10195-1: 5’%-in. Single Slide Rack Mounting Kit
Model 10195-2: 5X-b,. Dual Slide Rack Mounting Kit
Model 1651: 5&Ampere Shunt
Model 1681: Clip-On Test Lead Set
Model 168s RFPmbe
Model 1685: Clamp-On Current Pmbe
Model 1751: General Purpose Test Leads
Model 1754: Universal Test Lead Kit
Model 5806: Kelvin clip Leads
Model 7W7-I: Shielded IEEE-488 Cable, lm
Model 7007-2: Shielded IEEE-488 Cable, 20,
Model 7008.3: IEEE-488 Cable, 3 ft. (O.Ym)
Model 7008-6: IEEE488 Cable, 6 ft. (1.8m)
Prices and specifications Subject to change without notice.

TABLE OF CONTENT!3
SECTION l-GENERAL INFORMATION
1.1 INTRODUCTION. ........................................................................... l-1 ..
1.2 FEAI-URES ...... .;. ................ ;~:~.~.... .;.e:.;. .. .;. ....................................... .~.-.~:.: l-l
1.3 WARRANTY INFORMATION ................................................................. l-1
1.4 MANUAL ADDENDA .......... ; .............................................................. l-l
1.5~ SAFETY SYMBOLS AND TFRMS ............................................................... l-l
:p7 SPECIFICATIONS ............................................................................ l-2
INSPECTION .............................................. . .................................... l-2
1.8 USING THE MODEL 196 MANUAL .......................................................... l-2
1.9 GE’JTMG STARED ............................. .; ......................... ..~~...._~...~..:.. .;. ....... 1-2
1.10 ACCESSORIES .................... .~:.~.~;~.~..~;~..~~.~;-;;~.‘;~.~..~;~;;:~.~.
.... : .... .;~;; .~~.-.:.:~.-;~;: .~:;~......... l-3
SECTION 2-BASIC DMM OPERATIONS
2.1
2.2
2.2.1
2.2.2
2.2.3
2.2.4
2.3
23.1
2.3.2
2.33~
2.3.4
2.4
2.4.1
2.4.2
2.4.3
2.5
2.6
2.6.1
2.6.2
2.6.3
2.6.4
2.65
2.6;6
2.6.7
2.68
2.6.9
2.6.10
2.6.u.
2.7
27.1
2.7.2
2.7.3
2.%4
2.75
2.7.6
2.7.7
2.7.8
2.7.9
INTRODUCTION ........................................................................... 2-l
POWER UP PROCEDURES ......... _._.~.............................. ..I.. ....................... 2-l
Line rower ................................................... : ................................. 2-1
Power-Up sequence. ............................................................................ 2-l
Factory Default Conditions ................................................................. 2-l
User Programmed Conditions ................................................................. 2-2
FRONT PANEL FAMILIARIZATION .......................................................... 2-2
DisplayandIndicators ...................................................................... 2-2
controls.. ........................................................................................ 2-2
~1nputTermine.k ............................................................................. 2-4
Calibration Enable Switch ................................................................... 2-4
REAR PANEL FAMILIARIZATION ....................................................... __.... 2-5
Controls ................................................................................... 2-5
Connectors and Terminals .................................................................... 2-5
Fuses.. ..... _. ....... . ............................................................................. Z-6
ERROR DISPLAY MESSAGES. ..~.;Z:..; ..................... ~...~;. ... . .;...:~;.=;
...... ........ ;~~;~;::~2-6.
BASIC MEASUREMENTS ..................................................................... 2-6
WarmUpPeriod ........................................................................... 2-7
Zero.........................~............~.~.......~ ......................................... 2-7
Filter ....................................................................................... 2-8
DCVolta eMeasurements..
H ... ~.~~..~...=_
................. ..: . ..*-. ....................... .~. .... 2-9 ~~~
.Low-Leve Measurement Coiisiderations ..................................................... 2-10
Resistan& Measurements ................................................................... 2-11
TRMS ACVoltageMeasurements ........................................................... 2-12
Current Measurements (DC or TRMS~~AC)
.... ;. ........... .I ............................... 2-13
dBMeasurements ......................................................................... 2-13
:TRMS Considerations ...................................................................... 2-15
~~dBApplications ....................... .: ................ :.~
.......... :..~: .............. . ........ 2-17
FRONT PANEL PROGRAMS ................................................................... 2-17
Program 0 (Menu) ........................................................................ 2-18
Program2(Resolution) .................................................................... 2-18
Program4(MX+B)~. ........................................................................... 2-18
Program5~/LO/Pass).....................; .............................................. 2-19
Program 6 (Multiplexer, Auto/CAL) .......................................................... 2-20
Program30(Save)..................~.....~ .................................................. 2-20
Program 31 (IEEE Address). .......................................................................... ~2-21
Program 32 (Lie Frequency) ....................................................... _. ........... 2-21
Program 33 (Diagnostic). ..................................................................... 2-22
i

2.7.10 Program 34 (MX+B Pammeters) ............................................ .,..... _~.... __.... 2-22
2.7.11 Program 35 (HI/LO Limits) .............................. .,...... .,............................ 2-22
2.%x? Program36(Calibration) ................................................................... 2-23
27.13 mgram 37 (Reset) .................. .,.... __. ................. -. ............................ 2-23
2.7.14 Programn ................................................................................ 2-24
2.7.15 Program ZERO.. .............. .: .~;:.~.~.
.............................. .I. ...... I~.~:.-........... .l~. 2-24
2.7.16 Program FILTER................. ..~.._~~
................................................... .._. 2-24
2.7x7 Program dB ................................. _,_,_............................................ 2-25
2.8 FRONT PANEL TRIGGERING ................................................................. 2-25
2.8.1 One-ShotTrigge~ring.. ........ I.~...;..~ .................. .;..... T. ..I. ............................. 2-25
2.8.2 Triggering Readings Into Data Store. ..................... .,.... __............................. .,.. Z-25
2.9 EXTEEWAL TRIGGERING ........................................... _. ........................ 2-26
2.9.1 ExternalTrigger.. .......................................................................... 2-26
2.9.2 Voltmeter Complete ................... .~._...._. ............. ___~......................... ._ .... 2-26
2.9.3 ~Trigering Example.. ...................................................................... 2-27
SECTION 3-IEEE-488 PROGRAMMING
3.1
3.2
3.3
3.4
3.5 ~~~,
3.6
3.6.1
3.6.2
3.7
3.7.1
3.%2
3.8
3.8.1
3.8.2
3.8.3
3.8.4
3.8.5
3.8.6
3.8.7
3.8.8
3.9 ~
3.9.1
3.9.2
3.9.3~
3.9.4
3.9.5
3.9.6
3.9.7
3.9.8
3.9.9
3.9.10
3.9.11
3.9.32
3.9.13
3.9.14
3.9.15
3.9.16
3.9.17
3.9.18
ii
INTRODUCTION.. ........................................................ ................... 3-l
A SHORTCUT TO IEEE-488 OPERATION ........................................................ 3-l
BUS CONNECTIONS.. ................... ....~.~_~..~_............................................ 3-4
INTERFACE FUNCTION CODES .............................................................. 3-5
PRJMARY ADDRESS SELECTION ...................................... _........... _......... 3-6
CONTROLLER PRO%RAMMING ........ _. ................................................... ~3-6
Controller Handler Softwae .................................................................. 3-7
BASIC Interface Programming Statements. .................................................... 3-7
FRONT PANEL ASPECTS OF IEEE-488 OPERATION .......................................... ____ ,3-7
FrontPanelErrorMessages.. ... ~;.;~.~..:...:~~ ... . ....................... ~..~..~...~;.~.............. . 57
IEEE-488 Status Indicators and LOCAL Key .................................... .~I..... ._ ....... 3-10
GENERAL BUS COMMAND PROGRAMMIN G ................................................ 3-n
REN (Remote Enable) ..................................................................... .,. 3-ll
IFC (Tnterface Clear) ....................... ___.,............................................. 3Xl
LLO (LocalLockout).......................................................~ ................ 3-11
GTL(GoToLocal). ........................................................................ 3-12
DCL(Devi?e Clear) ........................................................................ 3-12
~SDCtSelective De& Clear), .................. 1. _.~..... -. ........... ._.......................... 3-13
GET Group Execute Trigger) .................................. -~.~......... t. ................. 3-n
Se&d Polling (SPE,SPD). .1.. ................ .-;. ........ .: .................................... 3-13
DEVICE-DEPENDENT COMMAND PRWWNG ............................. _..:.. ;,.... .,
.... 3-14
Execute(x). ................................................. .._. ........................... 3-17
Fur&on (F) ................ ; .............................................................. 3-17
Range(R). ...................... .._ ...................................................... 3-18
zero(Z). ......................................................... ..- ....................... 3-18
Filter(P).......................~~............................................................3- .
Rate (S). ........ .;. ......................................................................... 3-19
Trigger Mode Q ............................................................................ 3-20
Reading Mode (B) ............................. __.......................................... 3-20
Data Store Interval (Q) and Size (I) 3-20
Value (V) and Calibration (C) .......................................................... ............................................................... 3-22
Default Conditions (L) .............................................................. .~:.... : 3-23
DataFormat(G). .... . ............. ;~:. ............... :I;.....; .:. ........................ 3-23
SRQ Mask (M) and Serial Poll Byte Format .................................................. 3-24
EOI and Bus Hold-off Modes (K) ................................................................ 3-26
Terminator(Y) .............. ~..~..~...~...l~.~_. ........ _..........................................
status (u) ................................................................................... :I!
Auto/CalMultiplex (A). .................................................................... 3-29
Delay (W) .................................................................................... 331

3.9.19 ~Sem&~). ................................................... .._. . .._. . .- ................. 331
3.9.20 whitButton (H) ...................................................................... ~...~.~.~__.. 3-31
3.9.21 Display (D) ............................................................................... 332
3.9.22 lntemalFilter(N) ......................................................................... 3-33
3.10 TRANSLATOR SOFIWARE .................................................. ._. .... -~ ......... 3-33
3.10.1 Translator Format. ............................................................. _.,_~.,
. ., ....... ~3-34 ...
3.10.2 WildCard($). ............................................... . . c____. ... .._ .... .............. 335
3.10.3 NEW and OLD ................. .;~,..~..~.~.
...................... I. ... ,:~. ......................... 3-35~
3.108 Combining Translator Words .............. . .................. _.............. .,_................ 3-35
3.10.5 Combining Translator Words With Keithley IEEE-488 Commands .............................. 3-36
3.10.6 Executing Translator Words and Keithley IEEE Commands .................................... 3-36
3.10.7 SAVE.. ..................... ~;~.~...~v................................ 1;:. .......... ;.~. .... ;...;. 3-37
3.10.8 ~LIST ......................... _.~.
...... . ......................... .: ........................ 3-37
3.10.9 FORGET ............. :.I; ....... .._ ..................... ..~................................... 3-37
3.11 BUS DKC.4TRANSMISSION TIMES .......................................................... 3-37
SECTION 4-PERFORMANCE VERIFICATION
4.1
4.2
4.3
4.4
4.5
4.5.1
4.5.2
4.5.3
4.5.4
4.5.5
INTRODUCTION .............................................................................. 41
ENVIRONMENTAL CONDITIONS ............................ _. .. _. .................................. 4-1
INITIAL CONDITIONS. ..... -_*_..._..__._ ................ ~.~_~.................... ..-- ...... ..-- ...41
RECOMMENDEDTESTEQUIPMENT.. ................................ . ......... . ............... 41
VERIFICAXION PROCEDURES. ................................................................. 42
DC Volts Verification........................................ _____.______
...................... 4-2
TRMS AC Volts Verification ...... ..~.~......................~...I..~...........~.......~ .......... 4-2
Ohms Verification ......... ..~.._~:. ............ . ._ ......... . .m.,._ ...... ~.;;. ..... ;..~; ..:. .. .~..; ... 4-3
DCCurrentVerification.. .... ;I;. ....... ;~................ ~: ..... ~...~.;~;. ...... .~;~.~.-;.-;.......;. 4-4
TRMS AC Current Verification .............................. ~_-_................ ................ 4-5
SECTION 5-PRINCIPLES OF OPERATION
5.1
5.2
5.3
5.3.1
5.3.2
5.3.3
5.3.4
5.4
5.5
5.6
5.61
5.6.2
5.7
INTRODUCTION ........... .___~.~_~.~.~._.
........................................................ 5-l
OVERALL FUNCTIONAL DESCRIPTION ........................................................... 5-l
ANALOG CIRCUITRY.. ............................................ . .......... _:~................. 5-l
Input Signal Conditioning. .................... .~.~.~~-.
. .~;_. ................................ ; ........... 5-l
Multiplexer ................................................................................. 5-4
~+2.1VReference Source ........... ............. . .................... -. .... ~~~.~~:.~~.................. 5-7
Input Buffer Amplifier ......................................................... .: ............ ....
A/D CONVERTER ............... .._..~~.~_~_..................................~......_....._~ ... .55
CONTROL CIRCUITRY ....................................................................... 5-8
DIGITAL CIRCUITRY
Microcomputer. ........................................................................................................................................................ ;
Display Circuitry ................ ..~._.......................~....................~ ........... 5-9
POWER SUPPLIES .................... ..~.~...._..~ ............................................. 5-9
SECTION B-MAINTENANCE
6.1
6.2
6.3
6.3.1
6.3.2
6.4
6.4.1
6.4.2
INTRODUCTION .............................................................................. 6-l
LINE VOITAGE SELECTION ..................................................................
FUSE REPLACEMENT .................................................... ..~~.~...~..-*~~ ....
Line Fuses
.................................................................................. 6-l
CurrentFuse ....................... .
................
..,
... ____.: ......... ..._ ..
__:.: -;~
CALIBRKION ..... ........
.._....................~ ..................I,;;...;..;;.~....;.~~~:
...................
RecommendedCalibrationEquipment
Environmental Conditions. ....................... ..................
.) ................................................................................. .~_. 2;;
iii

6.4.3
6.4.4
6.4.5
6.4.6
6.4.7
t%
6.4.10
6.4.11
6.4.72
6.5
6.6
6.7
6.7.1
6.7.2
67.3
6.7.4
6.7.5
6.7.6
Warn-UpPeriod.. ............ ..I... ... I......,: ..:. .... ..:.~:..:...~ ..; ........... . ............. 6-3
CALENABLE Switch.. ................. ........................................................ 6-3
Front Panel Calibration ............... _.-. ...... .,
..... _. ....................................... 6-3
IEEE-488Bus~CaIibration.. .............. _....................... .._. __.__ _..................., .. ~.~6-4
Calibration Sequence .... !........ ,.._._
..:&.-. _. ...... ‘~-.,_.... .~_............................. __. _.. ,6,-4
DC V&s CaI’b1 *alon..t’ ............................ .._ .......................................... 6-5
Resistance Calibration. .......... .I .... _,....................................................... 6-6
TRMS~ACVtiltsCalibration.. ................... ;~..._.. :.:~:.~... . ............................... 6-7
DC Current Calibration ............. _. . __......... ... ._. ..................................... .,. 6-9
TRMS AC Currefit Calibration ................................................................ 6-10
DISASSEMBLYINSi-RUCTIONS .......... ~...__._ .,........I_ .......... ............................... 6-11
SPECIAL HANDLING OF STATIC-SENSI’?IVE DEVICES ........ _I...~............ ~&lZ
TROUBLESHOOTING ............. .~I,~_.
.................... .~:. - ..l..:.......... : ...... ... .,......................... .,... 6-12
Recommended Test Equipment ......... -., .. ..I. ................ ._,_ _~..,..__.
...................... 6-14
Power Up Self Test .................. .-~-._.~_._........... ._~.~.~.~.~.~.~..,. ___.,. .,...................... 6-14
Program 33 - Self Diagnostic Program ................ ._ ....... . _,............... __. ............. 6-14
Power Supplies ................... .~.~_.__-...... .___“.,_.............. _. ......................... 6-15
Signal COnditioning Check .-. .. .:.:~~.
....... .~-.:~........ _. ....... ._. ........................ _. .. 6-15
Digital and Display Circuitry Checks ........................................................ 6-15
SECTION 74iEPLACEABLE PAFITS
7.1 INTRODUCTION...~.~..~:~...;..;~..~.~..; .._.....I.... _......_......................_.._......_ _.. 7-1
Z2 PARTS UST..............................................~....................~..~......-.... 7-1
z3 ORDFRINGINFORMATION ..,................,. _..___........... ~-~. . . .~~.-- _..... ~-...1.~...~...-~~1~3~
%4 FACTORY SERVICE . . . .. . . .;..;.;....;...;;~-__.~.~-;; ._.. ~..__ . . . . . . . . . . . ...I_. . . . . . .. f. . . _. . ... . . ... . . ;rl
7.5 SCHEMp;TIC DIAGRAMS ps;rrj: COMPG&T LOC&TIOti DRAWINGS . . . . : .~.~.; __ . . .~.__. 7-l
APPENDIX A
ASCII CHARACTER CODES AND IEEE-488 MULTILINE INTERFACE COMMAND MESSAGES.. 1. A-1~
APPENDIX B
IBM PC/XT and MODEL 8573A PROGRAMMING . __. . . . . . _. . . ____. _. . _. ___. . . k-1
APPENDIX C
CONTROLLER PROGRAMS. .‘, . .‘:. . .,. . . ::. .~.. __ . . . _. .~.. . . _ . . . . . . , . . . . . :. . . _. . C-l
APPENDIX D
IEEE-488 BUS OVERVIEW . . . . ._ . . . . . . . . . . . . . . . . _. . . _. , . _. . ____. . . _. . . . . . _. __. D-l
iv

LIST OF TABLES
SECTION 2-BASIC DMM OPERATION
2-l
2-2
23
Et
2-6
2-7
2-8
Factory Default Conditions ...... .~I.:. . : .; ... :~. ................................................. 2-2
ErrorMessages .......... ..~.......;-.....................,......................; .............. 2-6
ResistanceRanges.. ............................ . ............................................ 2-12
Corresponding Voltage +ferenceJev$@for Impedance !7eference. ..................... .:...... ;~...... 2-15
Comparison of Average and TRMS Meter Readings ............................................. 2-16
FrontPanelPrograms.. ...... ~.:. .... . ..... :z.:. ... ~.:. ... .z.:..~ .:. ................. :.~........... 2-l7
Display Resolution ........................... ............. .,
.. .__...._............................. 2-18
ExampleMX+BReadings.:. ...... .:~................ . ....... . ............. ~;;.;;~;;. ... i...;;. 2-19~
SECTION 3-IEEE-488 PROGRAMMING
3-l
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-ll
3-12
3-13
3-14
3-35
3-16
IEEE-488 Commands Used to Select Function and Range ........................................ 3-3
~lEEEContact Designation. .............................. i ...................................... 35
Model 196 Interface Function Codes ............................................ _. ... _. ........ 3-6
BASIC Statements Necessary to Send Bus Commands ............................... 1.. ........... 3-7
FrontPanelIEEE488Messages.. .. I...; ........ :I............... l............ .................. 3-8~
General Bus Commands and Associated BASIC Statements ;~.
................. .~;................ 3-10
FactoryDefaultConditiotis ....... ~~;I.~;.~~...;.;.~~;....... ;;...~.J:.:..~..: ... . .... -..I~;~.~1.. ............ 3-12
Device-Dependent Command Summary ............................................ ._ .......... 3-E
Range Co~andSummary...~..,,:. ...................... :r:..~-..~.~ ~..~i:..%.
..... ........... -.!L. 3-l$
Rate Command Summary ........................................ _
... _ .. _ ................ _
...... 3-19
High Speed Data Store .......................................................................... 3-22
SRQ Command Parameters .................................................. _. .......... _
. __ 3-25
Bus Hold-off Ties ............................................ ._. ....... .~.~.:....... :. ............ __ 3-26
Translator Reserved Words and Chxacter .................................... _................ 3-33
Translator Error Messages ... z.................................................................... 3-34
Trigger To Reading-Ready Times (DCV Funct&~n) ............................................... 3-37
SECTION 4-PERFORMANCE VERIFICATION
41
4-2
22
45
46
RecommendedTest Equipment ................................................................ 41
Limits for DCV Volts Verification ................................................................ 42
LimitsforTRMSACVoltsVerifibation.. ........ . ....... MY..;
..................................... i-3
Limits for Ohms Verification ... .:~.;~.~.~........ ;...~ .................... .:. ...................... 4-4
Limits for DC Current Verification ............................................................. 4-4
Limits for AC CurretifVerification ....................... t.. .... ~.I; ...................... . ........ 4-5
SECTION 5-PRINCIPLES OF OPERATION
5-1 Input Buffer Amplifier (U35) Gain Co*gt&ation . . . . . . ‘. . . . . .‘; i . . . .~. . . . . _~._ . _. 5-7
V

SECTION 6-MAINTENANCE
6-l
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
6-J.0
6-12
6-12
6-13
6-14
LineVoltage Selection ............ ..L ......................................................... 6-l
LineFuseReplacement ....................................................................... 6-2
Current~Fuse Replacement ................................... _. ....... __. ...................... 6-2
Recommended Calibration Equipment .......................................................... 6-2
DCVoltsCalibration......................~.....- .............................................. 6-5
ResistanceCalibration ........................................................................ 6-6
TRMS AC Volts Calibration. ................. _,.. _._............................................... 6-7
DC Current Calibration ............ .~..................... ....................................... 6-10
TRMS AC Currefit calibration ....................................... _. ......................... 6-11
Recommended Troubleshooting Equipment .................................................... 6-14
Model I.96 Troubleshooting Mode .............................................................. 6-15
Power Stipply Checks. ................................................ _............ _
..... .,.. .,., 6-18
Digital Circuitry Checks. ........................................................................ 6-18
Display Circuitry Checks ..................... .,.. __............. _. ............................ 6-19
SECTION 7-REPLACEABLE PAFKS
7-1 Display Board, Parts List.. . . . . . . . . . . , . . . . __.-. .: . _. _ :. . . . _:. . . . . _. . . . . . :. . . . .‘.. ._ _. 7-3
7-2 DigitalBoard,PartsList........................-~.............................................. 7-S
7-3 AnalogBoard,Parts List . . . . . . . . . . . . . . . . . . . . ..~.............................................. 719
7-4 Model196MiscellaneousParts List . . . . . . . . . . . .. . . . . . . . . . . . .. . . . . . . .._........................ 7-33
APPENDIX B
B-1 BASIC Statements Necessary to Send Btis Commands........................................... B-1
APPENDIX D
D-l lEEE488Bus Command So ............................................................ D-3
D-2 Hexadecimal and Decimal Command Codes ................................................... D-7
D-3 Typical Addressed Command Sequence. ............................................. _.......... D-7
;; Typical Device-Dependent Commiind Sequence .. ;~.................... .; ..... . .. .;~..~............ D-7
IBEE Commaid Group ................ _..... ; .................................... .,....... .,.... D-7
Vi

LIST OF ILLUSTRATIONS
SECTION 2-BASIC DMM OPERATION
2-l
2-2
2-3
2-4
2-5
2-6
2-7
2-8
2-9
2-10
Model196FrontPanel................................................~.......~.......~- ....... 2-3
Model 196 Rear Panel ............................................................. .._ ........ 2-5
DCVoltageMeasurements ........................... ..~....~.....-...............~.-...~- ... 2-10
Two-TerminalResistance Measurements ................................................. .,
...... 2-11
Four-TerminalResistance Measurements ........................ .~.-..._~_.~__,_
..... _,__ ...... _ . .~_. ... 2-p
TRMSACVoltageMeasuremement
Current Measurements. .................................................................................................................................... $E
External Trigger Pulse Specifications .......................................................... 2-26
Voltmeter Complete Pulse Specifications
External Triggering Example ..................................... I
...................................... .,
......... .._..............._ ................. i;g
SECTION 3-IEEE-466 PROGRAMMING
3-l
3-2
2
3-5
3-6
37
3-8
3-9
3-10
TypicalProgramFlo~ Chart.. ~.y.:~I.T._ ~.~--.~:~.~.~. r
IEEE-488 Connector .. ................ ....... .................... ................................ ........
..- ........................-.:-~. :;4j
.....
IEEE-488Connections~. ................................... ~.:.~..;
.......................;: ....... .
............................ . .
IEEE-488 Connector Location ... .................
..*........~ ;;.~:3:
...
Contact Assignments ......................................................................... 3-5
~Generd Data Format ........................ _
...................................................... 3-23
SRQMask and Serial Poll Byte Fo~at.........................................~.....-...-..- . 3-24
UOMachine Status Word and Default V&es
Ul Error Status Word.... .... ........ ............................................................................................................. i;;:
Hit Button Command Numbers .............................................................. 3-32
SECTION 4-PERFORMANCE VERIFICATION
41
42
43
E
4-6
Conmctions ‘for DC Volts Verification .......................................................... 42
CoMectionsforTRMSACVoltsVeriCication~ ..... . ...... _:. ......... ..!. ....... . ................... 43
Connections for Ohms Verification (300%#$! Range) ............... _. ......................... 44
Connections for Ohms Verification (3OOkn--3OOMQRanges) ...................................... 44
Connections for DC Current Verification ........................................................ 45
Connections for TRMS AC Cur&t Verification ._.
.................................................... 4-5
SECTION &PRINCIPLES OF OPERATION
5-l
5-2
5-3
S-4
5-5
5-6
Overall Block Diagram. ....................................................................... 5-2
Input Configuration During 2 and 4Terminal Resistance Measurement. ........................... 5-3
Resistance Measurement Simplified Circi&y ................................................... 5-4
JFET Multiplexer ......................................................................................................... .,
Multiplexer Phases ............................................... ;:
A/D Converter Simplified Schematic ........................................................... 5-8
Vii

SECTION 6-MAINTENANCE
DC Volts Calibration Confii&on (300mV ani ,y @nges) ...................................... 6-5
DC Volts Calibration Confi~atio~ (3OV-300VRanges) ........................................... 6-5
Four-Wire Resistance Calibration Configuration (3000-3OkQRanges) ............................... 6-6
Two-Wire Resistance Calibration Configuration (300kO3OOMQRanges). ............................ 6-7
Flowchart of AC Volts Calibration Procedure .................................................... 6-8
TRMS AC Volts Calibration Configuration :.I.. ; .................................................. 1. ... 6-8
TRMS~AC Volts Calibration Adjustments ....................................................... 6-9
DC Current Calibration Configuration., ....................................................... 6-10
ACCurrent CalibrationConfiguration ......................................................... 6-U.
Analog Board Conne~ors~. .......... (. ......................................... .~.-i.. .............. 6-12~
Model196ExplodedViav .................................................................... 6-l3
SECTION 7-REPLACEABLE PARTS
7-1
7-2
7-3
z
7-6
Display Board, Comporient Location Drawing, Dwg. No. 196-110................................... ~7-4
Display Board, Schematic Diagram, Dwg. No. 196.XL6
.............................................. 7-5
Digital Board, Component Location Drawing, Dwg. No. 196-100.................... ;. ..; .~;; ....... ; . 7-12
Digital Board, Schematic Diagram, Dwg. No. 196-106. ............................... ‘.‘~.
......... : .. 7-13
Analog Board, Component Location Drawing, Dwg. No. 196.120.................................. 7-24
Analog Board, Schematic Diagram, Dwg. No. 196-126........................................... 7-25
APPENDIX D
D-l
D-2
D-3
tEEEBusCon@ration ...................................................................... D-l
IEEE Handshake Sequence ....... ;Y;~; .............................................. .;. ............. D-3
CommandCodes ............................................................................ D-6
viii

SECTION 1
GENERAL INFORMATION
1.1 INTRODU~ION 1.3 WARRANTY INFORMATION
The Keithley Model 196 System DMM is a five function
autoranging~digitalmultimeter. At 6% digit resolution, the
LED display can display ~*3,@0,1lOOcoo@s. The ran@ of
this analog-to-digital(A/D)converteris greatert+q the nor:
mal *l,999,999&tit~AAID converter used in many 6% &St
DMMs. The built-in IEEE-488~interface makes the instru-
ment fullyprogrammable overthe IEEE-488bus. The Model
196 can make the following basic measurements:
1. DC voltage measurements from lOOnVto 3OOV.
2. Resistance measurements from lOOpI tb’3OOM62.
3. TRMS AC voltage measurements from 1pV to 300V.
4. DC current me&urements from lnA to 3A.
5. TRMS AC current measurements from lnA to 3A.
Warranty information may be found on the inside front
cover of this manual. Should it become necessary to exq
c@e the warranty, contact your Keithley represent&e or
the ~factory to determine the proper course of action.
Keithley Instruments maintains service facilities in the
United States, United Kingdom and throughout Europe.
Information concerning the application, operation or ser-
vice of your instrument may be directed to the applications
engineer at any of these locations. Check the inside front
cover for addresses.
1.4 MANUAL ADDENDA
In addition to the above~ mentioned measurement
capabilities, the Model 196 can make:AC dB voltage and
current measurements.
Information concerning improvements or changes to the
instrument which occur after the printing of this manual
will be found on an addendum sheet included with the
manual. Be sure to review these changes before attempt-
ing to operate or service the instrument.
1.2 FEATURES 1.5 SAFETY SYMBOLS AND TERMS
Some important Model 196 features include:
l 10Character Alphanumeric Display-Easy to read 14seg-
ment LEDs used for readings and front panel messages.
*High Speed Measurement Rate-l000 readings per
second.
l Zero-Used to cancel offsets or establish baselines. A zero
value can be programmed from the front panel or over
the IEEE-488 bus.
l Filter-The weighted average digital filter can be set from
the front panel or over the bus.
l Data Store-Can stoti tip to 500 readings and is accessl%le
only over the bus.
l Digital Calibration-The instrument may be digitally
calibrated from either the front panel or over the bus.
l User Programmable Default Condition&&y inshument
measurement configuration can be established as the
power-up default conditions.
l Translator Softwze-User defined words (stored in non-
volatile memory) can be used to replace standard com-
mand strings over the IEEE-488 bus.
l Offset Compensated Ohms-Used to correct for small er-
ror voltages in the measurement circuit.
The following safety symbols and terms are used in this
manual or found on the Model 196.
The A symbol on the instrument denotes that the user
should refer tomthe -operating instruction iq this manual.
The I/y on the instrument denotes that a potential of
300Vor more may be present on the terminal(s). Standard
safety practices should be observed when such dangerous
levels are encomitered.
The WARNING used in this manual explains dangers that
could result in personal injury or death.
The CAUTION used in this manual explains hazards that
could damage the instrument:
1.6 SPECIFICATIONS
Detailed Model 196 specifications may be found preceding
the 7hble of Contents oft&is manual. ~. ~~~~
l-l

1.7 INSPECTION
The Model 196System DMM was carefully inspected, both
electrically and mechanically before shipment. After un-
packing all items from the shipping carton, check for any
obvious signs of physical damage that may have occurred
during transit. Report any damage to the shipping~agent.
Retain and use the originalpacking materialsin case reship-
ment is necessary. The following items are shipped with
every Model 196 order:
Model 196 System DMM
Model 196 Instruction Manual
Safety Test Leads (Model 3751)
Additional accessories as ordered.
Jf an additional instruction manual is required, order the
manual package (Keithley Part Number 196-901-00). The
manual package includes an instruction manual and any
applicable addenda.
1.8 USING THE MODEL 196 MANUAL
This manual contains information necessrny for operating
and servicing the Model 196 System DMM. The informa-
tion is divided into the following sections:
l Section 1 contains general information about the Model
396includiig that necessary to inspect the instrument and
get it operating as quickly as possl%le.
l Section 2 contains detailed operating information on
using the front panel controls and programs, making con-
nections and basic measuring techniques for each of the
available measuring functions.
l Section 3 contains the information necessary to connect
the Model 196to the IEEE488 bus and program operating
modes and functions from a controller.
l Se&on 4 contains performance verification procedures
for the instrument. This information willbe helpful ifyou
wish to verify that the instrument is operating in com-
pliance with its stated specifications.
l Section 5 contains a description of operating theory.
Analog, digital, power supply, and IEEE-488 interface
operation is included.
0 Section 6 contains information for servicing the instru-
ment. This section includes information on fuse replace-
ment, line voltage selection, calibration and
troubleshooting.
l Section 7 contains replaceable parts information.
1.9 GETTING STARTED
The Model 196 System DMM is a highly sophisticated in-
strument with many capabilities. Toget the instrument up
&id running quickly use the following procedure. Forcom-
plete information on operating the Model 196 consult the
appropriate section of this manual.
Power up
1. Plug the line cord intom~therear anel power jack and
plug the other end of the cordpinto an appropriate,
grounded power source. See paragraph 2.2.1 for more
complete information.
2. Press in the POWER switch to apply power to the in-
shument. The instrument will power up in the 3CWDC
*ange.
Making Measurements
‘L Connect safety~shrouded testyleads to the front panel
VOLTS H.Iand LO input terminals. Make sore the IN-
PUT switch on the rear panel is in the in (FRONT)
position.
2. Tomake avoltage measurement, simply connect the in-
put leads to a DC voltage source (up to 3OOV)and take
the reading from the display.
3. To change to a different measuring function, simply
press the desired function button. For -pie, to
measure resistance, press the OHMS button.
Using Front P.&e1 Programs
Program selection is accomplished by pressing the PRGM
button followed by the button(s) eat corresponds to the
program number or name. For example, to select Program
31 (IEEE), press the PRGM button and then the 3 and 1
buttons. ‘Ihble 2-7 lists and briefly describes the available
front panel programs. Once a program is selected the
following general rules will apply:
1. A displayed program condition can be entered by press-
i”p the ENTER button.
2. Program conditions that prompt the user with a flashing
digit can be modified using the data buttons (0 through
9 and i).
3. Programs that contain alternate conditions can be
displayed by pressing one ofthe range buttons. Each
press of one of these buttons togglesthe displaybetween
the two available conditions.
1-2

GENERALINFORMATION
4. A program will be executed when the ENTER button is
pressed.
5. A program can be exited at any time and thus not ey-
ecuted, by pressing the PRGM button.
Paragraph 2.7 provides the detailed information for using
the front panel programs.
1.10 ACCESSORIES
The following accessories are available to enhance the
Model l96s, capabilities.
Models lOl9A and 1019s Rack Mounting Kits-The Model
~1019Ais a stationary rack mounting kit with two front
panels provided to enable either single or dual side-by-side
mounting of the Model 196 or other similar Wthley in-
struments. The Model 10195 is a similar rack mounting kit
with a sliding mount configuration.
Model X301Temperature Probe-The Model 1301 is a rUg-
ged low cost temperature probe designed to allow temper-
ature measurements from -55 to I5O’C.
Model 16008 High VoltageProbe-The Model 16008 extends
DMM measurements to 40kV.
Model 165150Ampere Current Shunt-The Model 1651is
an external 0.00161+J% 4terminal shunt, which permits
current measurements from 0 to 50A AC or DC.
Model l&31 Clip-On Test Lead Set-The Model l68l’con
tains two leads, 1.2m (4 ft.) long terminated with banana
plugs and spring action clip probes.
Model 1682A RF Probe-The Model 1682A permits voltage
measurements from lOOkHato 25OMHz.AC toDC transfer
accuracy is *ldB from lOOkFIrto 25OhJH.zat IV, peak
responding, calibrated in RMS of a sine wave.
Model 1685 Clamp-On AC Probe-The Model 1685
measures AC current by clamping on to a single conduc-
tor. Interruption of the circuit is unnecessary. The Model
1685detects currents by sensing the chsnglng magnetic field
produced by the current~flow.
Model I751 Safety TestLeads-Finger gu$.s and shrouded
banana plugs help minimize the chance of making contact
with live circuitry.
Model 1754 Universal Test Lead Kit--The Model 1754 is a
12 piece test lead kit, with interchangeable plug-in ac-
cessories. Included in the kit is one set of test leads (l-red,
l-black), two spade lugs, two standard b-a plugs, two
phone tips (0.06 DIA.), two hooks and miniature alligator
clips (with boots).
Model 5804 Test Lead Set-The Model 5804, used for
4terminal measurements, includes: two test probes with
spring-loaded plunger clip adapters to fit test probes, two
spring-loaded plunger test clips with in-line banana jacks,
and four solid copper alligator clips with insulator boots.
Model 5805 Kelvin Probes-The Model 5805 includes two
spring-loaded Kelvintest probes (one red, one black), with
48-inch banana plug cable assemblies. A set of eight re-
placement contacts for the Model 5805 Kelvin test probes
is also available (Keithley PIN CS-551).
Model 5806 Kelvin Clip Lead Set-The Model 5806 includes
~twoI+in clip test lead assemblies with banana plug ter-
mination (one red, one black). A set of eight replacement
rubber bands for the lviode1~5806is also available (Keithkey
PIN GA-22).
Model 7087IEEE-&3 Shielded Cables-The Model 7007con-
nects the Model 196 to the IEEE-488 bus using shielded
cables to reduce electromagnetic interference (EMI). The
Model 7Ow-1is one meter in length and has a EMI shield-
ed IEEE-488 connector at:each end. The Model 7007-2 is
identical to the Model 7007-1,but is two meters in length.
Model 7088 IEEE488 Cables-The Model 7008~connectsthe
Model 196 to the IEEE-488 bus. The Model 7008-3 is D.9m
(3 ft.) in length and has a~standardIEEE488 connector at
each end. The Model 7008-6 cable is identical to the Model
7008-3, but~is 1.8m (6 ft.) in length.
Model 8573A IEEE488 Interface--The Model 8573A is an
IEEE1188 standard interface designed to interface the IBM
PC or XT computers to Keithley instrumentation over the
~IEEE-488bus. The interface system contains two distinc-
tive parts an interface board containing logic~to perform
the necessary hardware functions and the handler software
(supplied on disk) to perform the required control func-
tions. These two important facets of the Model 857ZAjoin
together to give the IBM advanced capabilities over
lXE-488 interfaceable instrumentation.
l-311-4

SECTION 2
BASIC DMM OPERATION
2.1 INTRODUCTION
Operation ofthe Model 196can be divided intotwo general
categories: front panel operation and IEEE-488 bus~opera-
tion. This section contains information necesssay touse the
instrument from the front panel. Thesesfunctions can also
be programmed overthe lEFE-488 bus, as described in Sec-
tion 3.
2.2 POWER UP PROCEDURE
2.2.1 Line Power
Use the following procedure to connect the Model 196 to
line power and power up the instrument.
1. Check that the instrument is set to correspond to the
availableline power.When the instrument leavesthe fac-
tov, the internally selected line voltageis marked on the
rear panel. Ranges are 105W25V or 2kW!5OV 5016OHz
AC. If the line voltage setting ofthe instrument needs
to be changed, refer to Section 6, paragraph 6.2 for the
procedure. If the line frequency setting of the instrument
needs tobe checked and/orchanged, utilize front panel
Program 32 (see paragraph 2.7.8) after the instrument
completes the power up sequence.
2. Connect the female end of the power cord to the AC
receptacle on the rear panel of the instrument.~Connect
the other end of the cord to a grounded AC outlet.
WARNING
The Model 196 is equipped with a 3-wire power
cord that contains a separate ground wire and
is designed to be used with grounded outlets,
When proper connections are made, instrument
chassis is connected to power line ground.
Failure to use a gmunded outlet may result in
personal injury or death because of electric
shock.
CAUTION
Be sure that the power line voltage agrees with
the indicated range on the rear panel of the in-
strument. Failure to obsenre this precaution
may result in instrument damage.
2.2.2 Power Up Sequence
The instrument can be turned on by pressing in the front
panel POWER switch. The switch will be at the inner most
position when the instrument is turned on. Upon ower
up, the instrument will do a number of tests on itse9 Tests
are performed on memory (ROM, RAM and ETROM). If
RAM or ROM fails, the instrument will lo& up. If ETROM
FAILS, the message ‘TINCAL!’willbe displayed. See para-
graph 67.2 for a complete description of the power up self
test and recommendations to resolve failures.
2.2.3 Default Conditions
Default conditions can be defined as setup conditions that
the instrument will return to when a particular feature or
command is asserted. The Model 196 will return to either
factory default conditions or user saved default conditions.
Factory Default Conditions
Atethe factory, the Model 196 is set up so that the instru-
ment is configured to certain setup conditions on the
initial power up. These factory default conditions are listed
in Tables2-l and 37 (located in Section 3). If alternate setup
conditions are saved (see User Saved Default Conditions),
the instrument can be returned to the factory default con-
ditions by running Program 37 (Reset). To retain the fac-
tory default condihons as power-up default conditions, run
Program30(Save} immediately after executing kograrn 37
(Reset).
Sending device-dependent command I.0 overthe IEEE-488
bus is equivalent to running Program 37 (Reset) and then
Program 30 (Save).
2-l

Table 2-1. Factory Default Conditions
Control/kahw
Zero value (rrogram ZERO)
dB
dB Reference Value
(program dB)
Filter
Filter Value (Program FILTER)
MX+B Status (Program 4)
MX+B Parameters (Program 34)
Multi
HI/LB lexer (Program 6) ‘-’ /l’ASS~~(l’rogrsm5)
HI/Lo Limits (Program 35)
Ohms Compensation (Program R
1)
kfault Condition
DCV
3cQV
6% Di ‘ts
Diiabgd
000.0000
Disabled
1.000000
Disabled
lo
Disabled
M=1.0OWOO~;~~
3=000.0000
Enabled
Disabled
+3.030000,
-3.o3clooo
Disabled
2.3 FRONT PANEL FAMILIARIZATION
The front panel layout of the Model 196is shown in Fiie
Z-l. The following paragraphs describe the various com-
ponents of the front panel in detail.
2.3.1 Display and Indicators
Display-The 10 character, alphanumeric, LED display is
used to display numeric conversion data, range and func-
tion mnemonics (i.e. mv) and messages.
Function Indicators-The indicator that is on identifies
which of the five operating functions is currently selected.
Rsnge Jndicator-When the instrument is in autorange the
AUTO indicator light will be on.
Modifier Indicators-When the zerofeature is enabled, the
ZERO indicator will torn on. When filter is enabled, the
FKTER indicator will turn on.
NOTE: The Model 196 is initially set for an IEEE address IEEE Status Indicators-These three indicators apply to in-
of 7. The line frequency is set to 50 nor6OHz. strument operation over the IEEE-488 bus. The RMT in-
dicator shows when the instrument is in the IEEE-488
remote state. The TLK and LSN indicators show when the
User Saved Default Conditions
Each function oft the Model 196 “remembers”~the last
measurement configuration that it was set up for (such as
range, zerovalue, filtervalue, et+ Switching back and forth
between functions willnot affect the unique tonfiguratioq
of each function. However,the instrument will “forget”the
configurations on power-down unless they are saved.
Unique setup conditions can be saved by running front
panel Program 30 (Save) or by sending device-dependent
command Ll aver the IEBE-488 bus. These~tiser saved
default conditions willprevsjl over the factory default con-
ditions on power-up, or when a DCL or SDC is asserted
over the bus.
IEEE Address and Lie Frequency
Any IEEE address and line frequency setting can be saved
as default conditions by running Program 30 (Save) or by
sending Ll over the bus. See paragraph 2.7 for complete
information on Programs 31 (IEEE Address) and 32 (Line
Frequency).
NOTE
An ‘TJNCAI!’ error will set the IEEE address to 7
and the line frequency to 6OHz.
instrument is in the talk and listen states respectively. See
Section 3 for detailed information on oueration over the
bus.
2.3.2 Controls
.&lI front panel co&ols, except the POWER and C%L
ENABLE switches, are momentary contact switches. In-
dicaton are located abovecertain buttons to show that they
are enabled. Some buttons have secondary functions that
are associated with front panel program operation. See
paragraph 2-7 for detailed information on front panel
prOg.3lllS.
El POWER-The POWER switch controls AC power to
the insbxment . Depressing and releasing the switch once
tams the power on. Depressing and releasing the switch
a second time turns the power off. The correct positions
footi\and off are marked on the front panel bythe POWER
ElFUNCTION GROUP
DCV-The DCV button places the instrument in the DC
volts measurement mode. The secondary function of this
button is to enter the i sign. See paragraph 2.6.4 for DCV
measurements.
2-2

BASIC DMM OPERATION
El
Figure 2-1. Model 196 Front Panel
ACV-The ACVbutton places the instrument in the ACvolts
measurement mode. The secondary function of this but-
ton is to enter the number 0. See paragraph 26.7 for ACV
measurements.
&The fl button places the instrument in the ohms
measurement mode. The secondary function of this but-
ton is to enter the number 1. See paragraph 2.6.6~for
resistance measurements.
DCA-The DCA button places the instrument in the DC
amps measurement mode. The secondary function of this
button is to enter the number 2. See paragraph 26.8 for
DC4 measurements.
ACA-The ACA button places the instrument in the AC
amps measurement mode. The secondary function of this
button is to enter the number 3. See paragraph 2.6.8 for
ACA measurements.
!zl RANGE GROUP
Manual-Each time the A button is pressed, the instru-
ment willmoveup one range, while the V button willmove
the instrument down one range each time its is
pressed. Pressing either of these buttons will cancel
autorange, if it was previous selected. The secondary func-
tions of these buttons are tomenter the number 4 (V) and
number 5 (A).
AUTO-The AUTO button places the instrument in the
autorange mode. While in this mode, the instrument will
go to the best range to measure the applied signal.
Autoranging is available for all functions and ranges.
Autoranging may be cancelled by pressing the AUTO but-
ton or one of the manual range buttons. The secondary
function of this button is to enter the number 6.
ZERO-The ZERO button turns on the ZERO indicator and
causes the displayed reading to be subtracted from subse-
quent readings. This feature allows for zero correction or
storage of baseline values. The secondary function of this
button isto select the ZERO program and enter the number
Z Refer to paragraph 2.62 for detailed information on the
zero feature.
2-3