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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 OUT option, 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 original 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, JNDIRECT, 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. Test Instrumentation Group All rights reserved. Cleveland, Ohio, U.S.A. Fourth PrintingJanuary 1992 Document Number: 196-901-01 Rev. 0

Safety Precautions
The following safety precautions should be observed befoE using this product and any associated inshvmentation. Although 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 precautions required to avoid possible injury. Read the operating information carefully before using the product. Exercise extreme caution when a shock hazard is present. Lethal 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 the product, test cables, or any other instruments while power is applied to the circuit under test. ALWAYS remove power from the entire test systern and discharge any capacitors before: connecting or disconnecting cables or jumpers, installing or removing switching cards, or making internal changes, such as installing 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 withstanding the voltage being measured. Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications 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 limited sources. NEVER cbnnect switching cards directly to AC tin. When connecting sources to switching cards, install $~~tive devices to lit fault current and voltage to the card. When fuses are used in a product, replace with same type and rating for continued protection against fire hazard. Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground connections. If you are using a test fxtwe, keep the lid closed while power is applied to the device under test. Safe operation requires the u.s$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 1oOOV more may be present on the terminals. Refer to the or product manual for detailed operahlng information. Instrumentation and accessories should not be connected to humans. Maintenance should be performed by qualified service personnel. Before perfo&ng any maintenance, disconnect the line cord~andall test cables.

SPECIFICATIONS
DC~ VOLTS 6% Digits,

ANALOG SETTLING of step change.

TIME:

on 300mV range), to 0.01%

LINEARI'IY Linearity is defined as the timurn
MAXIMUM less. ALLOWABLE INPUT:

CMRR: >lZOdB at dc, MHz or 6OHz (iO.O5%) with lkQ in either lead.
NMRR: >M)dB at50Hz or60Hz (iO.0546). ~~

deviation from a straight line between the readings at zero and full range: 1Oppm of range for ~3V-3ooV ranges; 15ppm of range for 3OOmV range; at 23OC il°C. 300V rms. 425" peak, whichever is

RESPONSE: CREST

Tiue root mean square,

ac coupled.

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: 3dBBANDWIDTHz MAXIMUM whichever SETTLING lMlI shunted bv <12OoF. 3WkHzfypical. INPUT: ' 3oOV -, ' 425" peak, 10' VHz,

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"):
INPUT *OHa-~0gz

.4CC"RAcY *a 1 Year, IP-WC ?OW-?c!

-. P??LUnoN

ALLOWABLE is less. TIME:

1 second to within 0.1% of change in reading.

WNETGURATION: Automatic 2- or&,ire. Offset compensationavai!ab~e on 3wiXOkO ranges, requires proper zeroing. Allowable compensation of ilOmV on 3OilQ range and ilWmV on 3ktl and 3OkO ranges. MAX, ALLOWABLE INPIJZ 3wV rms, 425V peak, whichever is less.

OBN

CIRCUIT

VOLTAGE:

5.5V maxinwm.

JJNEARIlY Linetity is defined as the madmum deviation from a &might line between the readings at zero and full range: 20ppm of range for SCO@3OkO ranges, at 23°C iYC.

tiAXIMUM READING RAT&
DCV, 3mA 10 n.4 0.05 + 10 * v DCA, ACV, ACA READINGS/SECOND conttn"ovs into Internal Buffer Extemal Rigger into I"temd Buffer Triggered via IEEE488 Bus

1ooP.A 0.05 + 10 +~ 3iE 1d 10 K.4 0.09 + 10 3 A `4wigit count error is 20. 3K-digit CO""terror is 5. MAXIMUMALLOWABLHINPUT: OVERLOAD PROTECTION: TEMPERATURE COEFFICIENT c iCO.1 x applicable accumw 3A, 250".

3A fuse (25OV), accessible from reii~ panel. (O"-18'C & 2S"-500C): svecification)PC. ~~~

1 For Sinewave inputs >x.m EOuntS.For 4Vdigit accuracy, divide cou*t error by 10. .%3lidigit accuracy, count errOI b 5. Jn 3vl- and 4K.digit modes,specificati`J"d apply for stnew.we inputs ,200Hz. RESPONSE: True mot mean square, ac coupled. accwacy for fundamental fquenCREST FACTOR (ratio of peak to rms): Up to 3:l allowable at % full scale. NONSINUSOIDAL INPUTS: Spe&d ctes
1 second to within 0.1% of change in reading. 3A, 250V. rear panel. ~' 3A fuse (UOV) accessibl&fiom

IEEE-488 BUS IMPLEMENTATION
MULTILINE COMMANDS: .~- SPE, SPD. UNILINE COMMANDS: INTERFACE FUNCTIONS: DCI. DTl, CO, El. DCL, LLO, SDC, GET, GTL; UNT, UNL, IFC, REN,~EOI, SKQ, ATN.

TEMPERATURE COEFFICIENT (O'-18'C & 28%d"Qi~ < f(O.l x applicable accuracy specification)i°C. dB (Ref. = ImA): INPUT -34 to +69 dB (ZOJ4.4 3.4) to -54 to -34 dB @!A to 20PA) `4CC"RAcY *a 1 Year, 1S%B'C 2oH51okHz 0.2 0.9

SHl. AHl, T6, TBO, L4, LEO, SRl, RLl, ?PO,

RE8OLuTION 0.01 dB 0.01 dB

~~~~

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: MAXIMUM Manual or autoranging. READING: 3029999 counts in 6%.digit mode. 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 Model Model Model Model Model Model Model Model Model Model Model Model lOlYA-2: 10195-1: 10195-2: 1651: 1681: 168s 1685: 1751: 1754: 5806: 7W7-I: 7007-2: Kit

ZERO: Control subtract: on-scale value from subseqtient readings or allows value to be prog&nmed. CONNECTORS: Analog: Switch selectable Digital: TRIGGER input tid VOLTMETER panel, BNCs. WARMUP: DISPLAY: polarity. 2 hours to rated accuracy. 10, 0.5-in. alphanumeric LED digits with decimal point and Function and IEEE-488 bus status also indicated. Input Lo to IEEE Lo orpower line ground: 5oOVpeak. 5~xlC+ product. >lO'D paralleled by 4OOpF. interfront or rear, safety j&s. COMPLETE &put on iear

ISOLATION: max. VI+

DATA MEMORY: 1 to 500 locations, programmable. Measurement vals selectable from lms to 999999,&s or triggered. BENCH READING 3COMtl ranges). RATE: 5 readings/second (2lsecond

5'%-in. Dual Fixed Rack Mounting Kit 5'%-in. Single Slide Rack Mounting Kit 5X-b,. Dual Slide Rack Mounting Kit 5&Ampere Shunt Clip-On Test Lead Set RFPmbe Clamp-On Current Pmbe General Purpose Test Leads Universal Test Lead Kit Kelvin clip Leads Shielded IEEE-488 Cable, lm Shielded IEEE-488 Cable, 20, IEEE-488 Cable, 3 ft. (O.Ym) IEEE488 Cable, 6 ft. (1.8m)

on 30M8 and weighting, 1 to

FILTER: Weighted average (exponential). l/99.

Programmable

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).

Model 7008.3: Model 7008-6:

Prices and specifications Subject to change without notice.

TABLE OF CONTENT!3
SECTION l-GENERAL
1.1 1.2 1.3 1.4 1.5~ :p7 1.8 1.9 1.10

INFORMATION
l-1 .. l-l l-1 l-l l-l l-2 l-2 l-2 1-2 l-3

INTRODUCTION. ........................................................................... .~.-.~:.: ;~:~.~ .;.e:.;. .. .;. ....................................... .... FEAI-URES ...... .;. ................ WARRANTY INFORMATION ................................................................. ; .............................................................. MANUAL ADDENDA .......... SAFETY SYMBOLS AND TFRMS ............................................................... SPECIFICATIONS ............................................................................ . .................................... INSPECTION .............................................. USING THE MODEL 196 MANUAL .......................................................... ..~~...._~. ..~..: .;. ....... .. .; ......................... GE'JTMG STARED ............................. . ACCESSORIES .................... .~:.~.~;~.~..~;~..~~.~;-;;~.`;~.~. .... : .... .;~;; .~~.-.::~.-;~; : .~:;~......... .~;~; ;:~.~.

SECTION 2-BASIC
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

DMM OPERATIONS

2-l INTRODUCTION ........................................................................... 2-l _._.~.............................. ..I.. ....................... POWER UP PROCEDURES ......... 2-1 : ................................. Line rower ................................................... 2-l Power-Up sequence. ............................................................................ 2-l Factory Default Conditions ................................................................. 2-2 User Programmed Conditions ................................................................. 2-2 FRONT PANEL FAMILIARIZATION .......................................................... 2-2 ...................................................................... DisplayandIndicators 2-2 controls.. ........................................................................................ 2-4 ~1nputTermine.k ............................................................................. 2-4 Calibration Enable Switch ................................................................... __ .... 2-5 REAR PANEL FAMILIARIZATION ....................................................... 2-5 Controls ................................................................................... 2-5 Connectors and Terminals .................................................................... Z-6 Fuses.. ..... _. ....... . ............................................................................. 2-6. ~...~;. ... . ...... .;...:~;.=; ........ ;~~;~;::~ ERROR DISPLAY MESSAGES. ..~.;Z:..; ..................... 2-6 BASIC MEASUREMENTS ..................................................................... 2-7 WarmUpPeriod ........................................................................... ......................................... 2-7 Zero.........................~............~.~.......~ 2-8 Filter ....................................................................................... ................. .~. .... 2-9 ..: . ..*-. ....................... DCVolta eMeasurements.. ... ~.~~..~...=_ 2-10 .Low-Leve Measurement Coiisiderations ..................................................... H 2-11 Resistan& Measurements ................................................................... 2-12 TRMS ACVoltageMeasurements ........................................................... 2-13 .I ............................... Current Measurements (DC or TRMS~~AC).... ;. ........... 2-13 dBMeasurements ......................................................................... 2-15 :TRMS Considerations ...................................................................... .......... .: ................ :.~ :..~: .............. . ........ 2-17 ~~dBApplications ....................... 2-17 FRONT PANEL PROGRAMS ................................................................... 2-18 Program 0 (Menu) ........................................................................ 2-18 Program2(Resolution) .................................................................... 2-18 Program4(MX+B)~. ........................................................................... .............................................. 2-19 Program5~/LO/Pass).....................; 2-20 Program 6 (Multiplexer, Auto/CAL) .......................................................... .................................................. 2-20 Program30(Save)..................~.....~ ~2-21 Program 31 (IEEE Address). .......................................................................... _. ........... 2-21 Program 32 (Lie Frequency) ....................................................... 2-22 Program 33 (Diagnostic). .....................................................................

~~~

i

2.7.10 2.7.11 2.%x? 27.13 2.7.14 2.7.15 2.7.16 2.7x7 2.8 2.8.1 2.8.2 2.9 2.9.1 2.9.2 2.9.3

.,..... _~. __.... ... Program 34 (MX+B Pammeters) ............................................ .,...... .,............................ Program 35 (HI/LO Limits) .............................. Program36(Calibration) ................................................................... .,.... __. ................. -. ............................ mgram 37 (Reset) .................. Programn ................................................................................ .......... .l~. .............................. .I. .. . ... I~.~:.-. Program ZERO.. .............. .: .~;:.~.~. ................................................... .._. ..~.._~~ Program FILTER ................. _,_,_ ............................................ Program dB ................................. FRONT PANEL TRIGGERING ................................................................. .;..... T. ..I. ............................. One-ShotTrigge~ring.. ........ I.~...;..~ .................. .,.. .,.... __ ............................. Triggering Readings Into Data Store. ..................... _. ........................ EXTEEWAL TRIGGERING ........................................... ExternalTrigger.. .......................................................................... ._ .... .~._...._. ............. ___~. ........................ Voltmeter Complete ................... ~Trigering Example.. ......................................................................

2-22 2-22 2-23 2-23 2-24 2-24 2-24 2-25 2-25 2-25 Z-25 2-26 2-26 2-26 2-27

SECTION 3-IEEE-488
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

PROGRAMMING

................... 3-l INTRODUCTION.. ........................................................ 3-l A SHORTCUT TO IEEE-488 OPERATION ........................................................ 3-4 . . ..~.~_~..~_ ............................................ BUS CONNECTIONS.. ................... 3-5 INTERFACE FUNCTION CODES .............................................................. _........... _ ......... 3-6 PRJMARY ADDRESS SELECTION ...................................... ~3-6 CONTROLLER PRO% RAMMING ........ _. ................................................... 3-7 Controller Handler Softwae .................................................................. 3-7 BASIC Interface Programming Statements. .................................................... ____ ,3-7 FRONT PANEL ASPECTS OF IEEE-488 OPERATION .......................................... . 57 ~..~..~...~;.~ .............. FrontPanelErrorMessages.. ... ~;.;~.~..:...:~~ ... . ....................... .~I. .... ._ ....... 3-10 IEEE-488 Status Indicators and LOCAL Key .................................... 3-n GENERAL BUS COMMAND PROGRAMMIN G ................................................ .,. 3-ll REN (Remote Enable) ..................................................................... 3Xl __ _.,............................................. IFC (Tnterface Clear) ....................... ................ 3-11 LLO (LocalLockout).......................................................~ 3-12 GTL(GoToLocal). ........................................................................ 3-12 DCL(Devi?e Clear) ........................................................................ 3-13 1. _.~..... -. ........... ._ .......................... ~SDC Selective De& Clear), .................. t. ................. 3-n -~.~. ........ GET tGroup Execute Trigger) .................................. 3-13 .-;. ........ .: .................................... Se&d Polling (SPE,SPD). .1.. ................ ............................. _..:. . ;, .... .,.... 3-14 DEVICE-DEPENDENT COMMAND PRWWNG 3-17 .._. ........................... Execute(x). ................................................. 3-17 ; .............................................................. Fur&on (F) ................ 3-18 .._ ...................................................... Range(R). ...................... 3-18 ..- ....................... zero(Z). ......................................................... . Filter(P).......................~~............................................................3........ ......................................................................... 3-19 Rate (S). .;. 3-20 Trigger Mode Q ............................................................................ 3-20 __ .......................................... Reading Mode (B) ............................. 3-20 Data Store Interval (Q) and Size (I) .......................................................... 3-22 Value (V) and Calibration (C) ............................................................... .~:.... : 3-23 Default Conditions (L) .............................................................. 3-23 ;~:. ............... :I;.....; .:. ........................ DataFormat(G). .... . ............. 3-24 SRQ Mask (M) and Serial Poll Byte Format .................................................. 3-26 EOI and Bus Hold-off Modes (K) ................................................................ :I! _ .......................................... Terminator(Y) .............. ~..~..~...~...l~.~ ........ _. status (u) ................................................................................... 3-29 Auto/Cal Multiplex (A). .................................................................... 331 Delay (W) ....................................................................................

ii

3.9.19 3.9.20 3.9.21 3.9.22 3.10 3.10.1 3.10.2 3.10.3 3.108 3.10.5 3.10.6 3.10.7 3.10.8 3.10.9 3.11

.._. . .._. . .- ................. ~Sem&~). ................................................... ~...~.~.~__ .. whit Button (H) ...................................................................... Display (D) ............................................................................... lntemalFilter(N) ......................................................................... ._. .... -~ TRANSLATOR SOFIWARE .................................................. ......... _.,_~. .,....... ., Translator Format. ............................................................. . . c____. ... .._ .... .............. WildCard($). ............................................... I. ... ,:~. ......................... NEW and OLD ................. .;~,..~..~.~....................... Combining Translator Words .............. . .................. _ .............. .,_ ................ Combining Translator Words With Keithley IEEE-488 Commands .............................. Executing Translator Words and Keithley IEEE Commands .................................... 1;:. .......... ;.~. .... ;...;. SAVE.. ..................... ~;~.~...~v ................................ .: ........................ ~LIST ......................... _.~....... . ......................... FORGET ............. :.I; ....... .._ ..................... ..~................................... BUS DKC.4TRANSMISSION TIMES ..........................................................

331 3-31 332 3-33 3-33 ~3-34 ... 335 3-35~ 3-35 3-36 3-36 3-37 3-37 3-37 3-37

SECTION 4-PERFORMANCE
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

VERIFICATION

INTRODUCTION .............................................................................. 41 _. .. _. .................................. 4-1 ENVIRONMENTAL CONDITIONS ............................ ................ ~.~_~. ................... ..-- ...... ..-- ... 41 INITIAL CONDITIONS. ..... - _*_..._..__._ RECOMMENDEDTESTEQUIPMENT.. . ......... . ............... 41 ................................ VERIFICAXION PROCEDURES. ................................................................. 42 DC Volts Verification ........................................ ____ _._ __ ...................... ___ 4-2 4-2 ..~.~......................~...I..~...........~.......~ .......... TRMS AC Volts Verification ...... . ._ ......... . .m ...... ~.;;. ..... ;..~; ..:. .. .~..; ... 4-3 .,._ Ohms Verification ......... ..~.._~:. ............ ~: .~;~.~.-;.-;.......;. 4-4 DCCurrentVerification.. .... ;I;. ....... ;~ ................ ..... ~...~.;~;. ...... ................ ~_-_. ............... 4-5 TRMS AC Current Verification ..............................

SECTION 5-PRINCIPLES
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

OF OPERATION

........................................................ 5-l INTRODUCTION ........... .___~.~_~.~.~._. 5-l OVERALL FUNCTIONAL DESCRIPTION ........................................................... . .......... _:~ ................. 5-l ANALOG CIRCUITRY.. ............................................ . .~; ; ........... 5-l Input Signal Conditioning. .................... .~.~.~~-. _. ................................ 5-4 Multiplexer ................................................................................. 5-7 . .................... -. .... ~~~.~~:.~~. ................. ~+2.1V Reference Source ........... ............. .... .55 .: ............ Input Buffer Amplifier ......................................................... .._..~~.~_~_..................................~......_....._~ ... A/D CONVERTER ............... 5-8 CONTROL CIRCUITRY ....................................................................... ; DIGITAL CIRCUITRY Microcomputer. ........................................................................................................................................................ 5-9 ..~._.......................~....................~ ........... Display Circuitry ................ 5-9 ..~.~...._..~ ............................................. POWER SUPPLIES ....................

SECTION B-MAINTENANCE
6.1 6.2 6.3 6.3.1 6.3.2 6.4 6.4.1 6.4.2 6-l INTRODUCTION .............................................................................. LINE VOITAGE SELECTION .................................................................. ..~~.~...~..-*~~ .... FUSE REPLACEMENT .................................................... 6-l .................................................................................. Line Fuses -;~ I,;;...;..;;.~....;.~~~: .., ____.: ......... ..._ ..__:.: CurrentFuse . ................... ........ .................. CALIBRKION ....................... ................ ... ..... .._....................~ RecommendedCalibrationEquipment .................. ................................................................................. 2;; ....................... .) .~_. Environmental Conditions.
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

. ............. 6-3 Warn-UpPeriod.. ..I... ... I......,: ..:. .... ..:.~:..:...~ ..; ........... ............ 6-3 ........................................................ CALENABLE Switch.. ................. 6-3 _.-. ...... .,..... _. ....................................... Front Panel Calibration ............... .. ~.~6-4 _ ....................... .._. __.__ _..................., IEEE-488Bus~CaIibration.. .............. __. _.. ,6,-4 .. ............................. Calibration Sequence .... ! ........ ,.._._:&.-. _. ...... `~-. ,_. ... .~_ .._ .......................................... DC V&s CaI'b *alon.. ............................ 1 t' 6-5 6-6 Resistance Calibration. .......... .I .... _,....................................................... 6-7 ;~..._ .. :.:~:.~ ... . ............................... TRMS~ACVtiltsCalibration.. ................... .,. 6-9 _. ......... . __ ... ._. ..................................... DC Current Calibration ............. 6-10 TRMS AC Currefit Calibration ................................................................ 6-11 ~...__._ . ,........I_ .......... ............................... DISASSEMBLYINSi-RUCTIONS .......... : ...... _I...~............ ~&lZ - ..l..: .......... SPECIAL HANDLING OF STATIC-SENSI'?IVE DEVICES ........ .,... 6-12 .................... .~:. ... .,......................... TROUBLESHOOTING ............. .~I,~_. 6-14 -., .. ..I. ................ ._,_ _~. .,..__....................... Recommended Test Equipment ......... 6-14 .-~- ._.~_._........... ._~.~.~.~.~.~.~. . .,...................... .,. ___., Power Up Self Test .................. __. ............. 6-14 ._ ....... . _, ............... Program 33 - Self Diagnostic Program ................ 6-15 .~.~_.__-. ..... .___".,_. ............. _. ......................... Power Supplies ................... _. .. 6-15 ....... .~-.:~. ....... _. ....... ._. ........................ Signal COnditioning Check .-. .. .:.:~~. 6-15 Digital and Display Circuitry Checks ........................................................

SECTION 74iEPLACEABLE
7.1 Z2 z3 %4
7.5

PAFITS

INTRODUCTION...~.~..~:~...;..;~..~.~..; .._.....I.... _......_......................_.._......_ _.. 7-1 PARTS UST..............................................~....................~..~......-.... 7-1 ORDFRINGINFORMATION ..,................,. _.._ __........... ~-~ . . .~~.-- _..... ~-...1.~...~...-~~1~3~ . FACTORY SERVICE . . . . . . . . ;..;.;....;...;;~-__.~.~-;; ._.. ~..__ . . . . . . . . . . . ...I_ . . . . . . . . f . . . _ . . .. . . . .. . . . ;rl SCHEMp;TIC DIAGRAMS ps;rrj: COMPG&T LOC&TIOti DRAWINGS . . . . : .~ ; __ . . .~.__. 7-l .~.

APPENDIX

A
1. A-1~

ASCII CHARACTER CODES AND IEEE-488 MULTILINE INTERFACE COMMAND MESSAGES..

APPENDIX

B
. __. . . . . . _. . . ____. _. . _ . ___. .. k-1

IBM PC/XT and MODEL 8573A PROGRAMMING

APPENDIX

C
.`, . .`:. . .,. . . ::. .~.. __ . . . _. .~.. . . _ . . . . . . , . . . . . :. . . _. . C-l

CONTROLLER PROGRAMS.

APPENDIX

D
. . . . ._ . . . . . . . . . . . . . . . . _. . . _. , . _. . ___ _. . . _. . . . . . _. __. D-l

IEEE-488 BUS OVERVIEW

iv

LIST OF TABLES
SECTION 2-BASIC
2-l 2-2 23 Et 2-6 2-7 2-8

DMM OPERATION
2-2 2-6 2-12 2-15 2-16 2-l7 2-18 2-19~

.~I. :. . : .; ... :~.................................................. Factory Default Conditions ...... .............. ..~.......;-.....................,......................; ErrorMessages .......... . ............................................ ............................ ResistanceRanges.. .:...... ;~...... Corresponding Voltage +ferenceJev$@for Impedance !7eference. ..................... Comparison of Average and TRMS Meter Readings ............................................. :.~. .......... ...... ~.:. .... . ..... :z.:. ... ~.:. ... .z.:..~ .:. ................. FrontPanelPrograms.. .,.. .__ .... _ ............................. Display Resolution ........................... ............. . ............. ~;;.;;~;;. ... i...;;. .:~. ............... . ....... ...... ExampleMX+BReadings.:.

SECTION 3-IEEE-488
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

PROGRAMMING
3-3 35 3-6 3-7 3-8~ 3-10 3-12 3-E 3-l$ 3-19 3-22 3-25 3-26 3-33 3-34 3-37

IEEE-488 Commands Used to Select Function and Range ........................................ i ...................................... ~lEEE Contact Designation. .............................. _. ... _. ........ Model 196 Interface Function Codes ............................................ 1.. ........... BASIC Statements Necessary to Send Bus Commands ............................... .................. .. I...; ........ :I............... l............ FrontPanelIEEE488Messages.. .~;. ............... General Bus Commands and Associated BASIC Statements ;~.................. 1.. ....... ;;...~.J:.:..~..: ... . .... -..I~;~.~ ............ FactoryDefaultConditiotis ....... ~~;I.~;.~~...;.;.~~; ._ .......... Device-Dependent Command Summary ............................................ ...................... :r:..~-..~.~ ..... ~..~i: ..%. ........... -.!L. Range Co~andSummary...~..,,:. _...... _... _.. _ ................ Rate Command Summary ........................................ High Speed Data Store .......................................................................... _ . __ _. .......... SRQ Command Parameters .................................................. __ ._. ....... .~.~.:. ...... :. ............ Bus Hold-off Ties ............................................ _ ................ Translator Reserved Words and Chxacter .................................... Translator Error Messages ... z .................................................................... Trigger To Reading-Ready Times (DCV Funct&~n) ...............................................

SECTION 4-PERFORMANCE
41 4-2 22 45 46

VERIFICATION
41 42 i-3 4-4 4-4 4-5

................................................................ RecommendedTest Equipment Limits for DCV Volts Verification ................................................................ ........ . ....... LimitsforTRMSACVoltsVerifibation.. MY..;..................................... Limits for Ohms Verification ... .:~. ;~.~.~. ....... ;...~ .................... .:. ...................... Limits for DC Current Verification ............................................................. t.. .... ~.I; ...................... Limits for AC CurretifVerification .......................

. ........

SECTION 5-PRINCIPLES
5-1

OF OPERATION
. ... . . `. .. .. .`; i . . . . ~. . . . . _~. . _. 5-7 _

Input Buffer Amplifier (U35) Gain Co*gt&ation

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 6-l ..L ......................................................... LineVoltage Selection ............ 6-2 ....................................................................... LineFuseReplacement 6-2 _. ....... __. ...................... Current~Fuse Replacement ................................... 6-2 Recommended Calibration Equipment .......................................................... 6-5 .............................................. DCVoltsCalibration......................~.....6-6 ResistanceCalibration ........................................................................ 6-7 _, _._ .. ............................................... TRMS AC Volts Calibration. ................. 6-10 ....................................... .~..................... DC Current Calibration ............ 6-11 _. ......................... TRMS AC Currefit calibration ....................................... 6-14 Recommended Troubleshooting Equipment .................................................... 6-15 Model I.96 Troubleshooting Mode .............................................................. _............ _..... .,.. .,., 6-18 Power Stipply Checks. ................................................ 6-18 Digital Circuitry Checks. ........................................................................ 6-19 _. ............................ .,.. __ ............. Display Circuitry Checks .....................

SECTION 7-REPLACEABLE
7-1 7-2 7-3 7-4

PAFKS

Display Board, Parts List.. . . . . . . . . . . , . . . . __.-. .: . _ . _ :. . . . _:. . . . . _. . . . . . :. . . . .`. . ._ _. 7-3 DigitalBoard,PartsList........................-~.............................................. 7-S AnalogBoard,Parts List . . . . . . . . . . . . . . . . . . . . ..~.............................................. 719 7-33 Model196MiscellaneousParts List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .._........................

APPENDIX B-1

B
B-1

BASIC Statements Necessary to Send Btis Co mmands...........................................

APPENDIX
D-l D-2 D-3 ;;

D
D-3 D-7 D-7 D-7 D-7

............................................................ lEEE488Bus Command So Hexadecimal and Decimal Command Codes ................................................... Typical Addressed Command Sequence. ............................................. .; ..... Typical Device-Dependent Commiind Sequence .. ;~.................... _..... ; .................................... IBEE Co mmaid Group ................

_ .......... . .. .;~..~ ............ .,....... .,....

Vi

LIST OF ILLUSTRATIONS
SECTION 2-BASIC
2-l 2-2 2-3 2-4 2-5 2-6 2-7 2-8 2-9 2-10

DMM OPERATION
2-3 2-5 2-10 2-11 2-p $E 2-26 i;g

....... Model196FrontPanel................................................~.......~.......~.._ ........ Model 196 Rear Panel ............................................................. ... DCVoltageMeasurements ........................... ..~....~.....-...............~.-...~Two-Terminal Resistance Measurements ................................................. .,...... Four-Terminal Resistance Measurements ........................ .~.- ... _~_.~_ ..... _,__...... _,_ _. .~_.... TRMSACVoltageMeasuremement .................................................................................................................................... Current Measurements. External Trigger Pulse Specifications .......................................................... I ., Voltmeter Complete Pulse Specifications .._..............._ ..................................... ...................................... ................. External Triggering Example .........

SECTION 3-IEEE-466
3-l 3-2 2 3-5 3-6 37 3-8 3-9 3-10

PROGRAMMING

r -.:-~. :;4j ~.y.:~I.T ._ TypicalProgramFlo~ Chart.. .................... ~.~--.~:~.~.~. ................................ .......... ........................ ..... IEEE-488 Connector .. ................ ....... ;;.~:3: ~.:.~ ..; ;: . IEEE-488Connections~. ............................ . . ..*........~ ... ................. IEEE-488 Connector Location ................................... ... ....................... ....... 3-5 Contact Assignments ......................................................................... 3-23 _...................................................... ~Generd Data Format ........................ . 3-24 SRQMask and Serial Poll Byte Fo~at.........................................~.....-...-..i;;: UO Machine Status Word and Default V&es ............................................................................................................. Ul Error Status Word .... .... ........ 3-32 Hit Button Command Numbers ..............................................................

SECTION 4-PERFORMANCE
41 42 43 E 4-6

VERIFICATION
42 43 44 44 45 4-5

Conmctions `for DC Volts Verification .......................................................... ..!. ....... . ................... _:. ......... CoMectionsforTRMSACVoltsVeriCication~ ..... . ...... _. ......................... Connections for Ohms Verification (300%#$! Range) ............... Connections for Ohms Verification (3OOkn--3OOMQ Ranges) ...................................... Connections for DC Current Verification ........................................................ Connections for TRMS AC Cur&t Verification ._.....................................................

SECTION &PRINCIPLES
5-l 5-2 5-3 S-4 5-5 5-6

OF OPERATION
5-2 5-3 5-4 ;: 5-8

Overall Block Diagram. ....................................................................... Input Configuration During 2 and 4Terminal Resistance Measurement. ........................... Resistance Measurement Simplified Circi&y ................................................... ., JFET Multiplexer ............................................... ......................................................................................................... Multiplexer Phases A/D Converter Simplified Schematic ...........................................................

Vii

SECTION 6-MAINTENANCE
6-5 DC Volts Calibration Confii&on (300mV ani ,y @nges) ...................................... 6-5 DC Volts Calibration Confi~atio~ (3OV-300VRanges) ........................................... 6-6 Four-Wire Resistance Calibration Configuration (3000-3OkQ Ranges) ............................... 6-7 Two-Wire Resistance Calibration Configuration (300kO3OOMQRanges). ............................ 6-8 Flowchart of AC Volts Calibration Procedure .................................................... 1. ... 6-8 TRMS AC Volts Calibration Configuration :.I .. ; .................................................. 6-9 TRMS~AC Volts Calibration Adjustments ....................................................... 6-10 DC Current Calibration Configuration., ....................................................... 6-U. ......................................................... ACCurrent CalibrationConfiguration 6-12~ .~.-i.. .............. (. ......................................... Analog Board Conne~ors~. .......... 6-l3 .................................................................... Model196ExplodedViav

SECTION 7-REPLACEABLE
7-1 7-2 7-3 z 7-6

PARTS
~7-4 7-5 ; . 7-12 : .. 7-13 7-24 7-25

Display Board, Comporient Location Drawing, Dwg. No. 196-110. .................................. .............................................. Display Board, Schematic Diagram, Dwg. No. 196.XL6 ;. .. ; . ~; ....... ; Digital Board, Component Location Drawing, Dwg. No. 196-100 .................... `.`~. ......... Digital Board, Schematic Diagram, Dwg. No. 196-106. ............................... Analog Board, Component Location Drawing, Dwg. No. 196.120 .................................. Analog Board, Schematic Diagram, Dwg. No. 196-126 ...........................................

APPENDIX
D-l D-2 D-3

D
.;. ............. D-l D-3 D-6

...................................................................... tEEEBusCon@ration ;Y;~; IEEE Handshake Sequence ....... .............................................. CommandCodes ............................................................................

viii

SECTION 1 GENERAL INFORMATION
1.1 INTRODU~ION
The Keithley Model 196 System DMM is a five function autoranging~digital multimeter. At 6% digit resolution, the LED display can display ~*3,@0,1lOO coo@s. The ran@ of this analog-to-digital (A/D)converter is greater t+q the nor: mal *l,999,999&tit~AAID converter used in many 6% &St DMMs. The built-in IEEE-488~interface makes the instrument fully programmable over the IEEE-488 bus. The Model 196 can make the following basic measurements: 1. 2. 3. 4. 5. DC voltage measurements from lOOnVto 3OOV. Resistance measurements from lOOpI tb'3OOM62. TRMS AC voltage measurements from 1pV to 300V. DC current me&urements from lnA to 3A. TRMS AC current measurements from lnA to 3A.

1.3 WARRANTY

INFORMATION

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 service 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
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 attempting to operate or service the instrument.

In addition to the above~ mentioned measurement capabilities, the Model 196 can make:AC dB voltage and current measurements.

1.2 FEATURES
Some important Model 196 features include: 10 Character Alphanumeric Display-Easy to read 14segment 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 nonvolatile memory) can be used to replace standard command strings over the IEEE-488 bus. l Offset Compensated Ohms-Used to correct for small error voltages in the measurement circuit.
l

1.5 SAFETY SYMBOLS AND TERMS
The following safety symbols and terms are used in this manual or found on the Model 196. symbol on the instrument denotes that the user The A should refer tom -operating instruction iq this manual. the The I/y on the instrument denotes that a potential of 300V or 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 196 System DMM was carefully inspected, both electrically and mechanically before shipment. After unpacking 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 original packing materials in case reshipment 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.

1.9 GETTING

STARTED

The Model 196 System DMM is a highly sophisticated instrument with many capabilities. To get the instrument up &id running quickly use the following procedure. For complete information on operating the Model 196 consult the appropriate section of this manual. Power up 1. Plug the line cord intom~the rear 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 inshument. The instrument will power up in the 3CW DC *ange. Making Measurements `L Connect safety~shrouded testyleads to the front panel VOLTS H.I and LO input terminals. Make sore the INPUT switch on the rear panel is in the in (FRONT) position. 2. To make a voltage measurement, simply connect the input 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 pressi"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 toggles the display between the two available conditions.

1.8 USING THE MODEL 196 MANUAL
This manual contains information necessrny for operating and servicing the Model 196 System DMM. The information is divided into the following sections: 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 connections and basic measuring techniques for each of the available measuring functions. l Section 3 contains the information necessary to connect the Model 196 to 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 will be helpful if you wish to verify that the instrument is operating in compliance 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 instrument. This section includes information on fuse replacement, line voltage selection, calibration and troubleshooting. l Section 7 contains replaceable parts information.
l

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 eyecuted, by pressing the PRGM button. Paragraph 2.7 provides the detailed information for using the front panel programs.

Model 1754 Universal Test Lead Kit--The Model 1754 is a 12 piece test lead kit, with interchangeable plug-in accessories. 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 Kelvin test probes (one red, one black), with 48-inch banana plug cable assemblies. A set of eight replacement 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 termination (one red, one black). A set of eight replacement rubber bands for the lviode1~5806 also available (Keithkey is PIN GA-22). Model 7087 IEEE-&3 Shielded Cables-The Model 7007 connects 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 shielded 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~connects the Model 196 to the IEEE-488 bus. The Model 7008-3 is D.9m (3 ft.) in length and has a~standard IEEE488 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-488 bus. The interface system contains two distinctive parts an interface board containing logic~to perform the necessary hardware functions and the handler software (supplied on disk) to perform the required control functions. These two important facets of the Model 857ZA join together to give the IBM advanced capabilities over lXE-488 interfaceable instrumentation.

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 instruments. The Model 10195 is a similar rack mounting kit with a sliding mount configuration. Model X301 Temperature Probe-The Model 1301 is a rUgged low cost temperature probe designed to allow temperature measurements from -55 to I5O'C. Model 16008 High Voltage Probe-The Model 16008 extends DMM measurements to 40kV. Model 165150Ampere Current Shunt-The Model 1651 is 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 to DC transfer accuracy is *ldB from lOOkFIr to 25OhJH.z at 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 conductor. Interruption of the circuit is unnecessary. The Model 1685 detects currents by sensing the chsnglng magnetic field produced by the current~flow. Model I751 Safety Test Leads-Finger gu$.s and shrouded banana plugs help minimize the chance of making contact with live circuitry.

l-311-4

SECTION 2 BASIC DMM OPERATION
2.1 INTRODUCTION
Operation of the Model 196 can be divided into two general categories: front panel operation and IEEE-488 bus~operation. This section contains information necesssay to use the instrument from the front panel. Theses functions can also be programmed over the lEFE-488 bus, as described in Section 3. CAUTION Be sure that the power line voltage agrees with the indicated range on the rear panel of the instrument. 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 itse 9 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!' will be displayed. See paragraph 67.2 for a complete description of the power up self test and recommendations to resolve failures.

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 available line power. When the instrument leaves the factov, the internally selected line voltage is marked on the rear panel. Ranges are 105W25V or 2kW!5OV 5016OHz AC. If the line voltage setting of the instrument needs to be changed, refer to Section 6, paragraph 6.2 for the procedure. If the line frequency setting of the instrument needs to be checked and/or changed, 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.

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 instrument is configured to certain setup conditions on the initial power up. These factory default conditions are listed in Tables 2-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 conditions by running Program 37 (Reset). To retain the factory default condihons as power-up default conditions, run Program 30 (Save} immediately after executing kograrn 37 (Reset). Sending device-dependent comman d I.0 over the 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 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 196 is shown in Fiie Z-l. The following paragraphs describe the various components 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 function 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 zero feature is enabled, the ZERO indicator will torn on. When filter is enabled, the FKTER indicator will turn on. IEEE Status Indicators-These three indicators apply to instrument operation over the IEEE-488 bus. The RMT indicator shows when the instrument is in the IEEE-488 remote state. The TLK and LSN indicators show when the instrument is in the talk and listen states respectively. See Section 3 for detailed information on oueration over the bus.

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 lexer (Program 6) `-' HI/ /l'ASS~~(l'rogrsm LB 5) HI/Lo Limits (Program 35) Ohms Compensation (Program R1)

NOTE: The Model 196 is initially set for an IEEE address of 7. The line frequency is set to 50 nor6OHz. User Saved Default Conditions Each function oft the Model 196 "remembers"~ the last measurement configuration that it was set up for (such as range, zero value, filter value, et+ Switching back and forth between functions will not 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 will prevsjl over the factory default conditions on power-up, or when a DCL or SDC is asserted over the bus. IEEE Address and Lie Frequency

2.3.2 Controls
.&lI front panel co&ols, except the POWER and C%L ENABLE switches, are momentary contact switches. Indicaton are located above certain 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 by the POWER

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).

El FUNCTION 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.

NOTE An `TJNCAI!' error will set the IEEE address to 7 and the line frequency to 6OHz. 2-2

BASIC DMM OPERATION

El

Figure 2-1. Model 196 Front Panel
ACV-The ACV button places the instrument in the AC volts measurement mode. The secondary function of this button 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 button 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 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 functions of these buttons are tom enter 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 button or one of the manual range buttons. The secondary function of this button is to enter the number 6.

Manual-Each time the A button is pressed, the instrument will move up one range, while the V button will move

ZERO-The ZERO button turns on the ZERO indicator and causes the displayed reading to be subtracted from subsequent readings. This feature allows for zero correction or storage of baseline values. The secondary function of this button is to select the ZERO program and enter the number Z Refer to paragraph 2.62 for detailed information on the zero feature.

2-3

SAS\C DMM OPERATION

FIUER-The FIWER button turns on the FIUEl7 indicator and causes the instrument to start weighted averaging (1 to l/99) fhe readings. The factory default weighted average is l/10,but may be changed using the PIITER program (see paragraph 2.7.16). See paragraph 2.6.3 for filter operation. Selectin the PILTEK rogiam is one of the secondary functionsof&isbutton.&eothersecondaryfunctionisto~nter the number 8. dB-The dB button places the inshument~~in the dB measurement mode and may be used with the ACV and ACA functions. Under factory default conditions, measurements are referenced to 1V or lmA. However, the dB program may be used to change the referqce @ell. `JTh$ seconY day function of this button is to select the dB program and enter the number 9. See paragriph 2.6.9 for dB measurements. El CONTROL GROUP

the LOCAL button will be inoperative. See Section 3 for informa$on on operating the instnunent-over the IEEE488 bus.

2.3.3 Input Terminals

q

The ~inputterminals are intended to be used with safety shrouded test leads to help minimize the possibility of contact with live cikuits. Note that the terminals sre duplicated sideways on the rear panel and that the INPUT switch (also located on the rear panel) determines which set of termin& is Bctive. VOLTS 0HMS~i-J.I akd LQ-l'he VOLTS OHMS Hl atid LO terminals are used for making DC volts, AC volts and twowire resistance measurements. AMPS and LO-The AMPS and LO terminals are used for making DC current and AC cUrrent measurem&s.

PRGM-This button is used tom enter the frontspanel program mode.

OHMS SENSE HI and LO--The OHMS SENSE HI and LO ENTER-This button is used to enter program parameters. terminals are used with the VOJXS OHMS HI and LO terThis button will also trigger a reading when the instruments minals to make four-wire resistance measurements. is in a one-shot trigger mode. El LQCA&When the instrument is in the IEEE-488 remote state (RM'I indicator on), the LOCAL button will return the instrument to front panel operation. However, if local lockout (LLO) was asserted over the IEEE-488 bus,

2.3.4 Calibration

Enable Switch

q

Calibration of the Model 196 can only be done if the CAL ENABLE switch is in the enable position. See paragraph 6.4 for details.

2-4

BASIC DMM OPERATION

2.4 REAR PANEL FAMILIARIZATION

2.4.2 Connectors

and Terminals

pJ AC Receptacle-Power is applied through the supplied The reax panel of the Model 196 is shown in Figure 2-2. ~~~ power cord to the 3-terminal AC receptacle. Note that the selected supply voltage is marked on the rear panel near the line voltage switch. 2.4.1 Controls
ra T TkTc TIC%TTA,-C -t-L:a.r.2~L -A,-~ the hment El Input Terminals-The rear panel input terminals perform the same functions as the front panel input terminals. Paragraph 2.3.3 contains the description of the input terminals.

Iable lme voltage. see paragrapn 6.2 for the proset this switch. INPUT switch connects the instrument to either the front panel input terminals or the rear panel input terminals. This switch operates in same manner as the power switch. The front panel input terminals are selected when the switch is in the "in' position and the rear panel input terminals are selected when the switch is in the "0uV position.

L4INPUT-The

mu IEEE-488Carmector-This connector is used to connect the ins,e nt to the IEEE-483 bus. IEEE interface functions ym -rl-l x5 14,&ed below the connector.

Input-This BNC~connector is used to apply pulses to trigger the Model 196 to take one or more readings, depending on the selected trigger mode.

qEXTERNAL TRIGGER

Figure 2-2. Model 196 Rear Panel

2-5

BASIC DMf.4OPERATION

I3 VOITMFXER COMPLETE Output-T% BNC output connector provides a TTLcompatible negative-going pulse when the Model 196 has completed a read