Unknown KEI_196 KEI 196

User Manual: KEI_196

Open the PDF directly: View PDF .
Page Count: 160 [warning: Documents this large are best viewed by clicking the View PDF Link!]

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. YOU will

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 PO days.

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-i ncmii~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 OFT REMOVAL

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

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. 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 to avoid 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 the product, 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, 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 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 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 or more may be present on the terminals. Refer to the

product manual for detailed operahlng information.

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~and all test cables.

SPECIFICATIONS

DC~ VOLTS

6% Digits,

ANALOG SETTLING TIME: <lm.s (<2ms on 300mV range), to 0.01%

of step change. LINEARI’IY Linearity 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 3OilQ range 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 0.05 0.05 + +~ 10 10

3 A 10 K.4 0.09 + 10 * v

‘4wigit count error is 20. 3K-digit CO”“t error 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. ~~~

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, specifica-

ti‘J”d apply for stnew.we inputs ,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

(ZOJ4.4 to 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

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

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

~SDC t Selective 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/Cal Multiplex (A). .................................................................... 3-29

Delay (W) .................................................................................... 331

3.9.19 ~Sem&~). ................................................... .._. . .._. . .- ................. 331

3.9.20 whit Button (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.4 TRANSMISSION 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

~+2.1V Reference 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

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’b 1 *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

LIST OF TABLES

SECTION 2-BASIC DMM OPERATION

2-l

2-2

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

~lEEE Contact 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

4-2

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

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

6-13

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 Co mmands........................................... 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 Co mmaid Group ................ _ ..... ; .................................... ., ....... ., .... D-7

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-Terminal Resistance Measurements ................................................. .,

...... 2-11

Four-Terminal Resistance 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

3-5

3-6

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

UO Machine Status Word and Default V&es

Ul Error Status Word .... .... ........ ............................................................................................................. i;;:

Hit Button Command Numbers .............................................................. 3-32

SECTION 4-PERFORMANCE VERIFICATION

4-6

Conmctions ‘for DC Volts Verification .......................................................... 42

CoMectionsforTRMSACVoltsVeriCication~ ..... . ...... _:. ......... ..!. ....... . ................... 43

Connections for Ohms Verification (300%#$! Range) ............... _. ......................... 44

Connections for Ohms Verification (3OOkn--3OOMQ Ranges) ...................................... 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-300V Ranges) ........................................... 6-5

Four-Wire Resistance Calibration Configuration (3000-3OkQ Ranges) ............................... 6-6

Two-Wire Resistance Calibration Configuration (300kO3OOMQ Ranges). ............................ 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

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~ 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 instru-

ment fully programmable over the IEEE-488 bus. The Model

196 can make the following basic measurements:

1. DC voltage measurements from lOOnV to 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 10 Character 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 tom the -operating instruction iq this manual.

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 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 original packing materials in 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

396 includiig 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 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 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. To get the instrument up

&id running quickly use the following procedure. For com-

plete 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 in-

shument. The instrument will power up in the 3CW DC

*ange.

Making Measurements

‘L Connect safety~shrouded testy leads to the front panel

VOLTS H.I and LO input terminals. Make sore the IN-

PUT switch on the rear panel is in the in (FRONT)

position.

2. To make a voltage 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 toggles the display between

the two available conditions.

1-2

GENERAL INFORMATION

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

~1019A is 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 X301 Temperature 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 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 lOOkHa to 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 conduc-

tor. 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.

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 Kelvin test 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

~two I+in clip test lead assemblies with banana plug ter-

mination (one red, one black). A set of eight replacement

rubber bands for the lviode1~5806 is also available (Keithkey

PIN GA-22).

Model 7087 IEEE-&3 Shielded Cables-The Model 7007 con-

nects the Model 196 to the IEEE-488 bus using shielded

cables to reduce electromagnetic interference (EMI). The

Model 7Ow-1 is 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~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 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 857ZA join

together to give the IBM advanced capabilities over

lXE-488 interfaceable instrumentation.

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~opera-

tion. 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 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

available line power. When the instrument leaves the fac-

tov, 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.

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 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 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

Ate the 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 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 con-

ditions by running Program 37 (Reset). To retain the fac-

tory 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

Zero value (rrogram ZERO)

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’rogrsm 5)

HI/Lo Limits (Program 35)

Ohms Compensation (Program R

kfault Condition

DCV

3cQV

6% Di ‘ts

Diiabgd

000.0000

Disabled

1.000000

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 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 zero feature 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 nor 6OHz. 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, 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 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 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

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.

2-2

BASIC DMM OPERATION

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 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 will move up one range, while the V button will move

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 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 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 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 func-

tionsof&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, measure-

ments are referenced to 1V or lmA. However, the dB pro-

gram 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 measure-

ments.

El CONTROL GROUP

PRGM-This button is used tom enter the fronts panel pro-

gram mode.

ENTER-This button is used to enter program parameters.

This button will also trigger a reading when the instruments

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,

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 ~input terminals are intended to be used with safety

shrouded test leads to help minimize the possibility of con-

tact 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 two-

wire resistance measurements.

AMPS and LO-The AMPS and LO terminals are used for

making DC current and AC cUrrent measurem&s.

OHMS SENSE HI and LO--The OHMS SENSE HI and LO

terminals are used with the VOJXS OHMS HI and LO ter-

minals to make four-wire resistance measurements.

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

The reax panel of the Model 196 is shown in Figure 2-2. ~~~ pJ AC Receptacle-Power is applied through the supplied

power cord to the 3-terminal AC receptacle. Note that the

selected supply voltage is marked on the rear panel near

2.4.1 Controls the line voltage switch.

ra T TkTc TIC%TTA,-C -t-L:- a.r.2~L -A,-~ the hment El Input Terminals-The rear panel input terminals per-

form the same functions as the front panel input terminals.

Iable lme voltage. see paragrapn 6.2 for the pro-

set this switch. Paragraph 2.3.3 contains the description of the input

terminals.

L4 mu IEEE-488 Car

INPUT-The INPUT switch connects the instrument mector-This connector is used to con-

to either the front panel input terminals or the rear panel nect the ins,e nt to the IEEE-483 bus. IEEE interface

input terminals. This switch operates in same manner as functions ym -rl-l

x5 14,&ed below the connector.

the power switch. The front panel input terminals are

selected when the switch is in the “in’ position and the q

EXTERNAL TRIGGER Input-This BNC~connector is

rear panel input terminals are selected when the switch is used to apply pulses to trigger the Model 196 to take one

in the “0uV position. or more readings, depending on the selected trigger mode.

Figure 2-2. Model 196 Rear Panel

2-5

BASIC DMf.4 OPERATION

I3 VOITMFXER COMPLETE Output-T% BNC output

connector provides a TTLcompatible negative-going pulse

when the Model 196 has completed a reading. It is useful

for triggering other inshumentation.

2.4.3. Fuses

El LINE FUSE-The line fuse provides protection for the

AC power line input. Refer to paragraph 6.3.1 for the line

fuse replacement procedure.

El CURRENT FUSkhe 3A current fuse provides pro-

tection for the current measurement circoits of the instru-

ment. Refer to paragraph 63.2 for the cwr$nt fuse replace-

ment procedure.

2.5 ERROR DISPLAY MESSAGES

Table 2-2 lists and explains the various display messages

assodated with incorrect front panel operation of the Model

196.

Table 2-2. Error Messages

Message

UNCAL

NO PROGRAM

O.VERFLO KQ

TRIG-ERROR

AC ONLY

NO RANGE

CONFLICI

Explanation

EIPROM failure on power up. See

paragraph 6.7.2.

Invalid entry while trying to select

program.

Overrange-Decimal point position

and mnemonics define function

and range (3kfl range shown).~ Th:

number of characters in the

“OVERFLO” message defines the

display resolution (6Yzd resolution

shown).

Trigger received while still pro-

cessing reading from last trigger.

Selecting dB with in&ument fitit

in ACV or ACA.

Pressing a range button while in

ACV dB or ACA dB.

196 in invalid state (i.e. dB func-

tion), when entering calibratioti

p*ogram.

2.6 BASIC MEASUREMENTS

The following paragraphs describe the basic pwxdures for

making voltage, resJs@~ce, current, and~dB measurements.

To optimize safety when measuring voltage in high energy

distribution circuits, read and use the directions in the

following warning.

WARNING

Dangerous arcs of an explosive nature in a high

energy circuit can cause severe personal injury

or death. If the meter is connected to a high

energy circuit when set to a current range, low

resistance range or any other low impedance

range, the circuit is virtually shorted. Dangerous

arcing can also result when the meter is set to

a voltage range if the minimum voltage spacing

is reduced.

When making measurements in high energy circuits use

test leads that meet the follcwing requirements:

l Test leads should be folly insulated.

l Only use test leads that can be connected to the circuit

(e.~,jz~~~~.clips, spade lugs, etc.) for hands-off

l Do not use test leads that decrease voltage spacing. This

diminishes arc protection and creates a hazardous

condition.

Use the following sequence when testing power circuits:

1. De-energize the circuit using the regular installed

connect-disconnect device such as the circuit breaker,

main switch, etc.

2. Attach the test leads to the circuit under test. Use ap-

propriate safety rated lead~s for this application.

3. Set the DMM to the proper function and range.

4. Energize the circuit using the installed connect-

disconnect device and make measurenwnts without

disconnecting the DMM.

5. De-energize the circuit using the installed connect-

disconnect device.

6. Disconnect the test~leads from the circuit under test.

WARNING

The maximum common-mode input voltage (the

voltage between inout LO and chassis around)

is 506J peak. Exceeding this value may create

s shock hazard.

2-6

BASIC DMM OPERATION

2.6.1 Warm Up Period

The Model 196 is usable immediately when it is first turned

on. However, the instrument must be allowed to warm up

for at least~ two hours to achieve rated accuracy.

2.6.2 Zero

The zero feature serves as a means of baseline suppression

by aIlowing a stored offset value to be subtracted from

subsequent readings. When the ZERO button is pressed,

the instrument takes the currently displayed reading as a

baseline value. All subsequent readings represent~the dif-

ference between the applied signal level and the ~stored

baseline.

A baseline level can be established for any or all measure-

ment functions and is remembered by each function. For

example, a 1OV baseline can be established on DCV, a 5V

baseline can be established on ACV and a 1Okll baseline

can be established on OHMS. Theses levels will snot be

cancelled by switching back and forth between functioti.

Once a baseline is established for a measurement function,

that stored level will be the same regardless of what range

the Model 196 is on. For example, if 1V is established

as the baseline on the 3V range, then the baseline will also

be 1V on the 30V through 30lV ranges. A aem baseline level

canbeaslaigeasfullrange. ~~

NOTE

The followirg discussion on dynamic range is

based on a display resolution of 6% digits. At 5’/zd

resolution, the number of counts would be reduced

by a factor of 10. At 4Yzd resolution, counts would

be reduced by a factor of 100 and 3%d resolution

would reduce counts by a factor of 1000.

By design, the dynamic measurement range of the Model

196, at 6%-d@ resolution, is M)60000 counts.1 With zero

disabled, the displayed reading range of the instrument is

*303ooOO counts. With zero enabled, the Model 196 has

the capability to-display ~606OCOO counts. This increased

display range ensures that the dynamic measurement range

of the instrument is not reduced when using a zero baseline

value. The following two examples will use the maximum

allowable zero values (3030000 counts and -3030008

counts) to show that dynamic measurement range wilI not

be reduced. It is important to note that the increased display

range does not increase the maximum allowable input level

to the instrument. For example, on the 3V range, the Model

196 will always overrange when more than k3.03V is con-

nected to the input.

Example l-The instrument is set to the 3V DC range and

a maximum -3.03OOOOV is established as the zero value.

When -3.03OOOOV is connected to the input of the Model

196, the display will read O.OMlOOClV. When +3.03OCEOV is

co.nnected to the input, the display will read +60600ooV.

Thus, the dynamic measurement range of the Model 196

is OV to 6.06V, which is 6060000 counts.

Example 2-Ihe instrument is still set to the 3V DC range,

but a maximum +3.03oOOOV ia the zero level. When

+3.03oO~CGV is connected to the input of the Model 196, the

display will read O.O@XtOOV When Y3.0~ is connected

to the input, the display will read -6.06OOOCV. Thus the

dynamic measurements range of the instrument is -6.06V

to OV, which is still 6060000 counts.

Zero Correction-The Model 196 must be properly zeroed

when using the 3OOmV DC or the 3OOB range in order to

achieve rated accuracy specifications. To use ZERO for zero

correction, perform the following steps:

Disable zero, if presently enabled, by pressing the

ZERO button. The ZERO indicator will turn off.

Select the 3oOmV DC or the 30022 range.

Connect the test leads to the input of the Model 196 and

short them together. If four-wire resistance

measurements are to be made, connect and short all four

leads together. Allow any thermals to stabilize.

Note: At5% and 6%~digit resolution, low level measure-

ment techniques need to be employed. Use Kelvin test

leads or shielded test leads. See paragraph 2.6.5 for low

level measurement considerations.

Press the ZERO button. The display will read zero.

Remove the short and connect thetest leads to the signal

or resistance to be measured.

Note: Test lead, resistance is also~ compensated for when

zeroing the 3OO’J range with the above procedure.

Baseline Levels-Baseline values can be established by

either applying baseline levels to the instrument or by set-

ting baseline values with the front panel ZERO program.

paragraph 27’15 contains the complete procedure for using

the ZERO program. To establish a baseline level by apply-

ing a level to the Model 196, perform the following steps:

1. Disable zero, if presently enabled, by pressing the ZERO

button. The ZERO indicator will turn off.

2. Sele&a function and range that is appropriate for the

anticipated measurement.

3. Chnect the desired baseline level to the input -of the

Model 196 and note that level on the display

2.7

BASIC DMM OPERATION

4. Press the ZERO button. The display will zero and the

ZERO indicator will be enabled. The previously

displayed reading will be the stored baseline. The rero

baseline value will also be stored in Program ZERO,

replacing the previous zero value.

WARNING

With ZERO enabled, a hazardous voltage

baseline level (rt4OV or more), not displayed,

may be present on the input terminals. If not

sure what is applied to the input, assume that

a hazardous voltage is present.

5. Disconnect the stored signal from the input and connect

the signal to be measured in its place. Subsequent~

readings will be the difference between the stored value

and the applied ‘signal.

Notes:

1. Disablmg zero cancels the zero baseline value on that

selected function. However, since the zero value is

automatically stored in Program ZERO, the zero baseline

value can be retrieved by using the program as long as

the ZERO button is not ~again pressed (see paragraph

2.Xi5 for details). Pressing the ZERO button, thus enabl-

ing zero, will wipe out the previous baseline value in Pro-

gram ZERO. Baselines established on other functions are

not affected.

2. To store a new baseline on a selected function, zero must

first be disabled and then enabled again. The new value

will be stored with the first triggered conversion. The

baseline value wi.lI also be stored as~the zero value in

Program ZERO, cancelling the previously stored value.

3. Setting the range lower than the suppressed value wi.lI

overrange the display; the instrument will display the

overrange message under theses conditions.

4. When the ZERO button is pressed to enable zero, the

ZERO indicator light will blink until an on scale reading

is available to use as a zero level.

2.6.3 Filter

The Model 196 incorporates two filters; a digital filter con-

trolled from either the front panel or over the IEEE-438 bus,

and an internal filter controlled exclusively from over the

bus.

Digital Filter-The Model 196 utilizes a digital filter to at-

tenuate excess noise present on input signals. This filter

is a weighted average type.

The factory default filter weighting is l/l@ but can be

changed to a weighting from 1 (l/l) to-1199 with the use

of the FILTER program. While in the program, the Model

196 will only display the denominator of the filter

Weighting. For example, if the current filter weighting is l/lo,

the FILTER program will display it as the value l0. Thus,

filter value as usecl in this discussion refers to the values

displayed by the Model 196 when in the FILTER program.

A falter value can be set for any or all measurement func-

tions and is remembered by each function. For example,

a filter value of 20 can be set for DCV and a filter value of

53 can be set~for ACV These filter values will not be can-

celled by switching back and forth between functions.

An advantage of using the filter is to stabilize the reading

-of a noisy input level. A consideration of filter usage is that

the larger the weighting, the longer the response time of

the display. Perform the following procedure to use the

filter:

1. If it is desired to cb.eck and/or change the filter value,

utilize Program FIITER as explained in paragraph 27.16.

2. Press the FILTER button. The FILm indicator will turn

on.

Notes:

1. When the filter is enabled, readings will be filtered before

being displayed. See Digital Filter Theory.

2. Pressing the FILIER button a second time will disable

the filter.

3. After a reading is triggered (continuous or one-shot), the

FIITER indicator light will blink for three time constants.

A time constant is measured in readings. The number

of readings in one time constant is equal to the filter

value. For example, for a filter value of IO, one time con-

stant~ is equal to 10 readings and three time constants

would be equal to 30 readings. The blinking duration will

be shorter in the 3%d mode since that has the fastest

reading rate.

4. In a continuous trigger mode, a reading that is outside

the filter window wiIl cause the FILTER indicator to blink

for one time constant.

Digital Filter Theory-The mathematical representation of

the weighted average digital Elter is as follows:

(new reading -AVG(t-I))

AVG(t) = AVG(t-1) + F

2-6

BASIC DMM OPERATION

where,

AVG(t) = displayed average

AVG(t-1) = old displayed average

F = weighting factor (filter value)

As with any filter, the Model 196 digital filter will affect

reading response time. The step response for this fiker~is

of the form:

step response = l-K’“+”

Where,

“K” is a constant based on the filter weighting~ factor

The step occurs when n=O. n=l is the first ream after

the step, n=2 is the second reading, etc.

Therefore:

step response = l- ( )

l- Y- a+1

Example:

F=10

n=5

Five readings sfter the step occurs, the display will be at

47% of the step change. After 10 readings (n=lO), the

display will be at 168% and after 20 readings, the display

wiU be at ~88%. The more the readings, the closer the

display will be to the step change.

To speed the response to large step changes, the Model 196

digital filter employs a “windo+ around the displayed

average. As long as new readings are within this window,

the displayed value is based on the weighted avemge equa-

tion. If a new reading is outside of this window, the

displayed value will be the new reading, and weighted

averaging WilI start from this point. The step response was

one reding to tbis change. The window in the Model 196

filter is lO,OoO counts for 6Yzd resolution, 1000 counts for

5Yzd, 7.00~ counts for 4Yzd and 10 counts for 31/2d.

Internal Filter-In addition to the front panel digital filter,

an inter& running avenge digita~fiher & -cd when msk-

ing high ~oh$ion and high sensitivity rriek+reme$k qe

enable&able status of the filter is controlled over the IEEE

bus. However, under factory default conditions, the in&~-

ment powers up with the filter enabled. When enabled,

this filtering only occurs when the instniment is in the 5Yz

OI blh-digit resolution niode.

Notes:

1. The front panel FILTER indicator light does not turn on

when the internal filter is activated. The indicator is only

used with the front~panel digital filter.

2. Contding the internal filter (on/off) over the IEEE bus

is explained in paragraph 3.9.22.

3. In a one-shot trigger mode, the Model 196 will not out-

put a reading until both filters have settled. Three time

constants are used to allow the filters to settle. A time

constant is measured in readings. The number of

readings in one time constant is equal to the filter value.

For example, for a filter value of lo,, three time constants

would be equal to 30 readings. If both the internal filter

and the front panel filter are in use, the time constant

is the sum of both filter values.

4. Filter windows for the internal filter function in the same

manner as the windows for the front panel filter.

However, the window sizes of the internal filter are much

bnaller than the front panel filter window sizes.

2.6.4 DC Voltage Measurements

The Model 196 can be.~ used tom make DC voltage

measurements in the range oft-*XlOnV to k3OOV. Use the

following procedure to make DC voltage measurements.

1. Select the DC volts fundion by pressing the DCV button.

2. Select a range consistent with the expected voltage or use

autorange.

3. Select the front or rear panel input terminals with the

INPUT switch.

NOTE

The 3oOmV DC range requires zero to be set in

order to achieve rated accuracy. The zero correc-

tion procedure can be found in paragraph 2.6.2.

2-9

BASIC DMM OPERATION

4. Connect the signal to be measured to the selected input Thus, an e, of 0.635pV would be displayed at 6Yzd resolu-

terminals as shown in Figure 2-3. lion as an additional six diaits of noise on the Model 196.

5. T&e the reading from the display To compensate for the dispgyed noise, use digital filtering

and then zero out the settled offset.

CAUTION:

MAXIFIUM INPUT = 300V RtlS. 425V PEAK

INPUT RESISTANCE = WJdiM:;Vs > IGIl

300G: 10.llln

Figure 2-3. DC Voltage Measurements

..~ .,

Shielding-AC voltages ‘Which &e extremely k&i corn-

pared with the DC signal may erroneously produce a DC

output. Therefore, if there is AC interference, the~~circuit

should be shielded with the shield connected to the Model

196 input Lo (particularly for low-level sources). Impropw

shielding can cause the Model 1% to behave in one or more

of the following ways:

1. Unexpected offset voltages.

2. Inconsistent readings between ranges.

3. Sudden shifts in reading.

To minimjze pick-up, keep-the voltage source and the

Model 196 away from strong AC magnetic sources. The

voltage induced due to magnetic flux is proportional to the

area of the loop formed by the input leads. Therefore,

m minimize the loop area of the input leads and connect each

2.6.6 Low-Level Measurement Considerations signd at ody one point.

Accuracy Considerations-For sensitive measurements,

other external considerations besides the Model I.96 will

affect the accumcy. Effects not noticeable wheti working

with higher voltages sre significant in nanovolt and

microvolt signals. The Model 196 reads only the signal

received at its input; therefore, it is important that tb.is

signal be properly bansmitted from the source. The follow-

ing paragraphs indicate factors which affect accuracy noise,

source resistance, thermal emfs and stray pick-up.

Noise and Source Resistance-The limit of sensitivity in

measuring voltages with the Model 196 is determined by

the noise present. The noise voltage at the Model 1% in-

put increases with sauce resistance.

For high impedance sources, the generated ~noise can

become significant when using the most sensitive mnge

(3COmV, 6Yzd) of the Model 196. As an -pie of deter-

mining e, (noise voltage generation due to Johnson noise

of the somce resistance), assume that the Model 196 is con-

nected to a voltage source with an internal resistance of

lM0. At a mom temperature of 20°C, the p-p noise Voltage

generated over a bandwidth of lHz will be:

e, = 635xXP’~Rxf

e, = 6.35 x lP d/(1 x W) (1)

e, = 0.635fiV

T&rmal EMFs-Thermal emfs (thermoelectric potentials)

are generated by thermal differences between the junction

of dissimilar metals. These can be large compared to the

signal which the Model 196 can measure. Thermal emfs can

cause the following problems:

-1. Instability or zero offset is much higher than expected.

2. The reading is sensitive to (and responds to) temperature

changes. This can be demonstrated by touching the cir-

cuit, by placing a heat source near the circuit or by a

regular pattern of instability (corresponding to heating

and air-conditioning systems or changes in sunlight).

3. To minim&e the drift caused by thermal emfs, use cop-

per leads to connect the circuit to the Model 196. A

banana plug is generally suitable and generates just a

few microvolts. A clean copper conductor such ss #lO

bus wire is about the best for this application. The leads

to the input may be shielded or unshielded, as necessary.

Refer to Shielding.

Widely varying temperatwes within the circuit can also

create thermal ends. Therefor& maintain Constant

temperatures to minimize these thermal ends. A card-

board box around the circuit under test also helps by

minimking air currents.

5. The ZERO cOntro1 can be used to null out constant off-

set voltages.

2-10

BASIC DMM OPERATION

2.6.6 Resistance Measurements

The Model 196 can make resistance measurements from

lOO#-l to 3CGMtI. The Model 196 provides automatic selec-

tion of 2-terminal or 4terminal resistance measurements.

This means that if the ohms sense leads are not connected,

the measurement is done Zterminal. If the sense leads are

connected, the measurement is done 4terininaI. For

4terminal measurements, rated accuracy can be obtained

as long as the msximum lead resistance does not exceed

the values listed in Table 2-3. For best results on the 3008

3kQ and 3OkQ ranges, it is recommended that 4terminal

measurements be made to eliminate errors caused by the

voltage drop across the test leads which will occur when

2-terminal measurements are made. The Model 5806 Kelvin

Test Lead Set is ideal for low resistance 4terminal

Offset-Compensated Ohms-Offs&-compensated ohms is

used to compensate for voltage potentials (such as thermal

EMFs) across the device under test. This feature eliminates

errors due to a low level external voltage source configured

in series with the unknown resistor. Offsets up to KhnV

on the 3OOn range and up to BlOmV on the other ranges

can be corrected with offset-compensation. This feature can

be used for both 2-terminal and 4terminal resistance

measurements up to 30k61. Offset-compensation is selected

through front panel Program !I (see paragraph 27.14).

especially the 3000 range. After offset-compep.sation is

enabled, the Model 1% should be properly zeroed.

To make resistance measurements, proceed as follows:

L Select the ohms function by pressing the Q button.

2. Select a range consistent with the expected resistance or

use autorange.

3. Select the f&t or rear panei input terminals using the

INPUT switch.

4. Turn offset-compensation on or off as needed, using Pm-

gram 0.

NOTE

If offset-compensatio~n is being used, the 3ooI1,

3ka and 3OkQ ranges require zero to be set in

order to achieve the best accuracy. The zero car-

rection procedure is located in paragraph 2.6.2.

5. For 2-terminal measurements connect the resistance to

the instnunent as shown in Figs 2-4. For 4terminal

measurements connect the resistance to the instrument

as shown in F&ire 2-5.

CAUTlON

During ohms offset compensated resistance measurements,

the Model 196 performs the following steps for each The maximum input voltage between the HI

anti LO input terminals is 425V peak or 300V

conversion: RMS. Do not exceed these values or instru-

1. Makes a normal resistance meaS,mment of the device. ment damage may occur.

In general, this consists of sourcing a current thmu 6. Take the reading from the’display.

the device, and measuring the voltage dmp acro~ tfz

device.

2. Turns off the internal -nt source and again measures

the voltage drop across the device. This is the voltage

caused by an external source.

3. Calculates and displays the corrected resistance value. SHKEf~D

n OPTIONAL SHIEY

I- ---

w UNDER TEST

Offset-Compensated ohms not only cowxts for small er-

ror voltages in the measurement circuit, but also compen-

sates for thermal voltages generated withim the Model 196.

In normal ohms, these thermal EMF offsets are accounted

NODEL 196 L---~-I

for during c&ration. Therefore, enabling offset-compensa-

tion wilI cause these offsets to appear in the’ readings, Figure 2-4. Two-Terminal Resistance Measurements

2-11

BASIC DMM OPERATION

OPTIONAL SHIELO

-~~- -

MODEL 196

B.&rward bias the diode by connecting the red terminal

of the Model 196 to positive side of the diode. A good

diode will typically measure between 3OOn to IkQ.

C.Reverse bias the diode by reversing the connections

on the diode. A good diode will overrange the display.

Table 2-3. Resistance Ranges

Maximum Test Lead

6%d Nominal Resistance (Q) for

Figure 2-5. Four-Terminal Resistance Measurements Range 1 Resolutim I-Short 1 -3 Count Error (Wzd)

I I I

MODEL 196

CAUTION:

MAX I MUM INPUT = 300V RMS, 425V PEAK. 1O’V.H.

INPUT IMPEDANCE = 1Hf-1 SHUNTED BY < 120pF

Figure 2-6. TRMS AC Voltage Measurement

Notes:

*5%d resolution only

NOTE: Typical open circuit voltage is 5V.

2.6.7 TRMS AC Voltage Measurements

The instrument can make TRMS AC voltage measurements

from l$I to 3OOV. To measwe AC volts, proceed as follows:

1. With ohms compensation active (Progam a), the 61 in- 1. Select the AC volts function by pressing the ACV button.

dicator light will blink when the ohms function is 2. Select a range con$stent with the expeqed voltage or use

selected. autorange.

2. Table 2-3 shows the current output for each resistance 3. Select the front or rear panel input terminals using the

range. INPUT switch.

3. It helps to shield resistance greater than IOOkQ to achieve

a stable reading. Place the resistance in a shielded

enclosure and electrically connect the shield to the LQ

input terminal of the instrument.

4. Diode Test-The 3kQ range can be used to test diodes as

MlOWS:

A. Select the 3kO range.

NOTE

There is a small amount of offset (typically 150

counts at 5%d) present when using the ACV func-

tion. Do not zero this level o-ut. Paragraph 2.6.10

provides an explanation of AC voltage offset.

4. Connecbthe signal to be measured to the selected input

terminals as shown in Figure 2-6.

5. Take the reading from the display.

2-12

BASIC DMM OPERATION

Clarifications of TRMS ACV Spedfications: ” 2.8.8 Current Measurements (DC or TRMS AC)

Msximum Allowable Input-The following graph sum-

marizes the maximum input based on ~the lWV*Hz

specification.

The Model 196 can m&e DC or TRW AC current measure:

ments from lnA (at 5Yrd resolution) to 34. Use the follow-

ing procedure to make current measurements.

MAXIIIUH INPUT TRt4S AC VOLTS I

FREOUENCY-HZ CAUTION: MAXIMUM CONTINUOUS INPUT=3A

1. Select the DC current or AC current function by press-

ing the DCA or ACA button respectively.

2. Select a range consistent with the expected current or

use autorange.

3. Select the front or rear panel input terminals using the

INPUT switch.

4. Connect the signal to be measured to the selected input

terminals as shown in Figure 2-7.

5. Take the reading from the display.

~. .- _ ._..

I I

Settling Time-lsec to within 0.1% of change in reading.

This the specification is for analog circuitry to settle and

does not in&de AID conversion time.

Figure 2-7. Current Measurements

Notes: 2.8.9 dB Measurements

1. See paragraph 26.10 for TRMS measurement conSid&

&iOllS.

2. When making TRMS AC voltage measurements below

45Hz, enable the front panel filter modifier to obtain

stable readings. A filter value of 10 is recommended.

3. To make low frequency AC mea%uenients in the range

of lOHz to 2oH.z:

A. The ACV function must be selected.

B. Digital filtering must be used to obtain a stable

reading.

C. Allow enough settling time before taking the reading.

The dB measurement mode makes it pocisible to compress

a large range of~measurements into a much smaller scope.

AC dB measurements can be made with the instrument in

the ACV or AC4 function. The relationship between dB

and voltage and currentxan be expressed by the follow-

mg equations:

dB = 20 log .%

0 V

2-13

At the factory the instrument is set up to be a dBV meter

when ACV dB is selected. dBV is defined as deciiels above

or below a 1V reference. The instrument will read OdB when

1V is applied to the input. The 1V reference is the factory

default reference. With ACA dS selected, the factory default

reference is lmA. The inskument will read OdB when lmA

is applied to the input.

Reference levels other than 1V and ImA can be established.

There are two methods that can be used to establish a dB

reference. One method is to use the zero feature. This

simply consists of applying a signal to the instrument and

pressing the ZERO button. That suppressed level& the dB

reference (OdB point). The alternate method is to utilize the

front panel dB program and enter the desired reference

value. An advantage of using the dB program is that-a

source is not needed to establish a reference.

The following procedure explains how to use the zero

feature to establish a reference:

1. Apply a voltage or current signal, that is to be used~as

the dB reference, to the input of the Model 196.

2. Press the ZERO button. The ZERO indicator will turn

on and the display will zero. The reference i?now

whatever the applied signal is.

3. Disconnect the signal from the instrument.

Program dB allows the user to check or change the dB

reference of the instrument. The recommended progmm-

mable voltage reference range is from lOpV to 9.99999v The

recommended programmabie current reference range is

from lOnA to 9.99999mA. Paragraph 27.77 contains the in-

formation needed for using the dB program.

AC dB Measurements-Perform the following steps to

make dB measurements:

l. Select the ACV or ACA function.

2. Select the front or rear panel input terminals with the

INPUT switch.

3. Check and/or change the dB reference as previously

explained.

4. Connect the signal to be measured to the inputs of the

Model 196.

5. ktite,the dB measurement mode by pressing the dB

6. Take the dB reading from the display.

WARNING

With dB enabled, a hazardous voltage baseline

level (~40V or more), not displayed, may be pre-

sent on the input terminals. If not sure what is

applied to the input, assume that a hazardous

voltage is present.

dBm MeasurementiBm is defined as decibels above or

below a lmW reference. dB~ measurements can be made in

terms of impedance rather than voltage or current. Because

the instrument ~cannof directly establish impedance

referenws, a v&age reference must be calculated and

established for a particular impedance reference. Use the

following equation to calculate the voltage refenznce need-

ed for a particular impedance reference:

For OdBm, V,., = JlmW l Z.,,

Example: Calculate the voltage reference needed to make

dBm measurements referenced to Mx)fi.

For OdBm, V,+ = ~O&lOlW :, 6OOQ ..,

3 46

= .77456v

Once the necessary voltage reference is known. it canbe

established in the Model 196 with the.dB program. Subse-

quent dBm readings will be referenced to the correspond-

in impedance reference. Table 2-4 lists the voltage

I erences needed for some commonly used impedance

references.

dBW Measurements-dBW is defined as decibels above or

below a 1W reference. dBW measurements are made in the

same manner as dBm measurements; that is, calculate the

voltage reference for a particular impedance and set the in-

strument to it with the dB program. The only difference

between dBm and dBW is the reference point; ZmW vs 1W.

The following equation can be used to ca&Jate the voltage

reference:

For OdBW, V,, = dlW*Z,,

2-14

Table 2-4. Corresponding Voltage Reference Levels

for Impedance References resulting is no error in the average-type meter reading,

Reference Reference

Impedance Impedance

(0 (0

150

300

600

1000

Reference Voltage

Level for:

OdBm OdBW

0.0894 2;828

0.2236

0.2739

0.3873

0.5477

0.7746

1.0000

,f for OdBm = -J lO?V*Z,

,*t for OdBW = 4 ZR,

2.6.10 TRMS Considerations

The situation changes with the half-wave rectified sine

wave. As before, the peak value of the waveform is IOV,

but the average value drops to 3.18V. The R&E value of

this waveform is 5V, but the average responding meter

wiUgiveareadingof35 (3.18xl.l~),~ealingan MOT

of29.4%.

A similar situation exists for the rectified square wave,

which has an average value of 5V and an RMS value of 5.CW.

The average responding meter gives a TRMS reading of

5.55V (5 x Lll), while the Model 196 gives a TRMS reading

of 5V. Other waveform comparisons can be found in Table

2-5.

AC Voltage Offset-The Model 196, at 5%d resolution, will

typically display 150 counts of offset on AC volts with the

input shorted. This offset is caused by the offset of the

TRMS converter. This offset will not affect reading accuracy

and should not be zeroed out using the zero feature. The

following equation expresses how this offset (V,,) is added

Most DMMs actually measure the average value of an in- to the signal input (V,.):

put waveform but are calibrated to read its RMS equivalent.

This poses no problems as long as the waveform being Disp1ayed reading = ’ @‘I=)’ + ‘V,,,)

measured is a pure, low-distortion sine wave. For complex,

nonsinusodial waveforms, however, measurements made Example: Range = 2VAC

with an averaging type meter can be grossly insccurafe. Offset = I.50 counts (1.5mV)

Because of its TRMS measuring capabilities, the Model 196 Input = ZOOmV RMS

provides accurate AC measurements for a wide variety of

AC input waveforms. Display reading = 4 (2OOmV)’ + (1.5mV)

Lz J 0.04v + (2.25 x 10-v)

TRMS Measurement Comparison-The RMS value of a = .200005V

pure sine wave is equal to 0.707 times its peak value. The

average value of such a waveform is 0.637 times the peak

value. Thus, for an average-responding meter, a correction The offset is seen as the last digit which is not displayed

factor must be designed in. This correction factor, K can at5%d resolution. Therefore, the offset is negligible. If the

be found by dividing the RMS valued by the average vsjue zero feature was used to zero the display, the I50 counts

as follows: of offset would be subtracted from Vj. resulting in an error

K = 0.707 / 0.637 of 150 counts in the displayed reading.

= 1.11 Crest Factor-The crest factor of a waveform is the ratio of

By applying this correction factor to an weraged reading, its peak value to its RMS value. Thus, the crest factor

a typical meter can be designed to give the RMS equivalent. specifies the dynamic range of a TRMS instrument; For

This works fine as long as the waveform is a pure sine, butt sinusoidal waveforms, the crest is 1.414. For a symmetrical

the ratios between the RMS and average values of different square wave, the a& factor is unity

waveforms is far from constant, and can vary considerably. The crest factor of other waveforms will, of course, depend

Table 2-5 shows a comparison of common types of on the waveform in question because the ratio of peak to

waveforms. For reference, the first waveform is an ordinary RMS value will vsrj~ For example, the crest factor of a rec-

sine wave with a peak amplitude of 1OV The average value tang&u pulse is related to its duty cycle; as the duty cycle

of the voltage is 6.37V while its RMS value is ZO7V Jf we ~decreases, the crest factor increases. The Model 196 has a

apply the 1.11 correction factor to the average reading, its maximum crest factor of 3, which means the instrument

can be seen thatboth meters will give the same reading, will give accurate TRMS measurements of rectangular

waveforms with duty cycles as low as 10%.

2-15

BASIC DMM OPERATION

Table 2-5. Comparison of Average and TRMS Meter Readings

Yaveform

iine

+,p------

la&Wave Rectied Sine

Ul-Wave Rectified Sine

;quare

+10-- --

?I- ~~~

Rectified Square Wave

Triangular Sawtooth

ic Coupled

Peak

Value

IOV

1ov

IOV

1ov

RMS

Value

7.07v

5.OOV

7.07v

lO.ow

5.cOv

,ov l fi

5.77v

Average

Responding

4&r Reading

7.07V

3.53v

7.07v

ll.lOV

5.55v

ll.lV* q

5.55v

,c Coupled

TRMS

Meter

Reading

7.07V

5.oov

7.07v

lO.ooV

5.OOV

1ov l fi

5.77v

Averaging

Meter

Percent Error

29.4%

11%

:.11fi-I) x 100

3.6%

BASIC DMM OPERATION

2.6.11 dB Applications

Measuring Circuit Gain/Loss-Any poimin a circuit can

be established as the OdB point. Measurements in that cir-

cuit are then referenced to that point expressed in terms

of gain (+dB) or loss (-dB). To set the zero dB point pro-

ceed as follows:

1. Place the Model 196 in ACV and dB.

2. Connect the Model 196 to the desired location in then

circuit.

3. Press the ZERO button. The display will read OdB.

4. Gain/loss measurements can now be made referenced

to the OdB point.

Measuring Bandwidth-The Model 196 can be used to

determine the bandwidth of an amplifier as follows:

1. Connect a signal generator and a frequency counter to

the input of the amplifier.

2. Set the Model 196 to ACV and autorange.

3. Comect the Model 196 to the load of the amplifier.

4. Adjust the frequency of the signsI generator until a peak

AC voltage reading is measured on the Model 196. This

is the center frequency.

5. Press the dB button and then press the ZERO button.

The OdB point is now established.

6. Increase the frequency input~until the Model 196 reads

-3.OOdB. The frequency measured on the frequency

counter is the high-end Emit of the bandwidth.

7. Decrease the frequency input until the dB reading again

falls to -3.OOdB. The frequency measured on the signal

generator is the low-end limit of the bandwidth.

Note: The bandwidth of the Model 196 is typically 3oOkHz.

Do not use this application to check amplifiers that exceed

the bandwidth of the Model 196.

Determining Q-The Q of B tuned circuit~can be deter-

mined as follows:

Table 2-6. Front Panel Programs

Program Description

0 (Menu) Display software level and list

available front panel

2 (Resolution)

4 (MX+B)

5 (HlILo/Pass)

Programs

Change display resolution

(3Yzd, 4%d, 5%d or 6%d).

Enable MX+B program.

Enable/disable HI/LO/Pass

6 W-9 ~ ~%lsaskus, enable/disable

3O(Save) ~ multiplexer.

Save currem instrmnent set

up.

31 (IEEE Address) Recall/modify IEEE address.

32 (Line Frequency) Recall/modify line frequency

33 (Self Test) setting (50/6OHz).

34 (MX+B Parameters; Enter self-test program.

Recall/modify MX+B program

values.

3.5 (HI/Lo Liits) Recalllmodify HI/LO limits.

36 (Calibration) Enter digital calibration

mode.

37 (Reset) Returns 196 to factory default

conditions.

n Recall status, enable/disable

offset ~comoensation.

ZERO

FluER

Recall/modify zero value.

RecaWmocbfy falter value.

Recall/modify dB reference

value.

Program Selection--Program selection is accomplished by

pressing the PRGM button followed by the button(s) that

corresponds to the program number or name. For exam-

ple, to select Program 31 (IEEE Address), press the PRGM

button and then the “3” and ‘7” buttons.

1. Determine the center frequency and bandwidth as ex- Data Entry--Program data is applied from the front panel

plained in the previous application (Measuring using the data buttons. The data buttons consist of the but-~

t ons~ labeled with the +-oolaritv sipn and numbers 0

Bandwidth).

2. Calculate Q by using the following formula: through~9.~ Data entry is &bmpl&hed”by pressing the ap-

propriate number button at each cursor location. Cursor

Q ‘= Center Frequency/Bandwidth location is indicated by the bright, flashing display digit.

The cu%or moves one digit to the right every time a number

is entered. After entering a number at the least significant

2.7 FRONT PANEL PROGRAMS display digit, the cursor will move back to the most signifi-

cantdiait; Polarity fi button) can be changed with the cm-

There are I.7 programs available from the front panel of the sor at &y display character.‘I’lus (+) is &plied and thus,

Model 196. These ~tiroamms are Listed in Table 26. The not displayed,

following paragraphs describe and explain the operation

of each program.

2-17

Once a program is selected, the following general Mes wiu

=PPlY:

1. A displayed program condition can be entered by press-

im the ENTER button.

2. P&gram conditions that prompt the user with a flashing

digit (cursor) can be modified using the data buttons (0

through 9). Polarity (i button) can be changed with the

msor on any character. Plus (+) is implied and thus,

not displayed.

3. Program.5 that contain alternate conditions can be

display:d by pressing one of the range buttons. Each

press of one of these buttons toggles the display between

the two available conditions.

4. A program will be executed when the pressed ENTER

button causes the instrument to exit the program.

5. A program can be exited at any time and thus not ex-

ecuted, by pressing the PRGM button.

2.7.1 Program 0 (Menu)

This program displays the software revision levels of the

Model 196 and lists the available front panel progr-. Per-

form the following steps to use this program:

1. Press the PRGM button. The following prompt-will be

displayed:

PROGRAM ?

2. Enter the number 0 by pressing the “0” button. The soft-

ware level of the instrument will be displayed, For ex-

ample, if the software level is Bl, the following message

will be displayed:

SOFTREV 81

3. Use the manual Range buttons to scroll through the front

panel programs. The A range button scmlls forward

while the y range button scrolls backward.

4 To exit from the menu, press the PRGM button. The in-

strument will retnrn to the previous operating state.

2.7.2 Program 2 (Resolution)

Program 2 selects the number of display resolution digits.

The resolution available is dependent on function and

range. Table 2-7 lists the display resolution availabie for the

various function/range combinations. Display resolution

can be set for each function and is remembered by each

function as long as the instrument remains powered up.

Resolution can be remembered after power-down by run-

ning Program 30 (Save). To change the display resolution,

perform the following procedure:

1.~ Set the in+ument to the desired fun@iqn and range.

2. Press the PRGM button. The following prompt will be

displayed:

PROGRAM ?

3. Enter the number 2 by pressing the “2” button. The cur-

rent resolution status will then be displayed. For exam-

ple, if the selected function is currently set for 6% digits

of resolution, the following message v+l be displayed:

6% d

4. If an altered resolution is desired, use the manual Range

buttons to display the resolution. The V Range button

decreases resolution, while the A Range but&n in-

creases resolution.

5. With the desired resolution displayed, press the ENTER

button. The instrument will return to the previously

selected function and range.

Table 2-7. Display Resolution

Function Range

DCV All

ACV AU

Available

Resolution

31/2d, 4%d, 5Hd, 61hd

3%d, 4%d, 5%d

DCA IAll ( 3%d, 4%d, 5Yzd

I I

I AcA I- 3%d, 4Hd, Shd I

2.7.3 Program 4 (MX+B)

This program allow3 the operator to automatically multiply

normal display readings (X) by a constant (M) and add a

constant (B). The result (Y) will be &played in accordance

with the formula, Y=MX + B. This program is useful when

slope calculations are required for a series of measurements.

The values of M and B can be char& by utilizing Pro-

gram 34. Perform the following steps to enable the MX t

B feature:

1. Set the Model 196 to the desired function and range.

2. Connect the signal to be measured (x) tvthe input of

the Model 196.

2-16

BASIC DMM OPERATION

3. If the values of M and B need to be checked or changed,

do so using Program 34.

4. Press the PRGM button. The following prompt will be

displayed:

PROGRAM ?

5. Enter the number 4 by pressing the “4” button. The cur-

rent status of the MX+B program will be displayed. For

example, if the MX+B is currently disabled, the follow-

ing message will be displayed:

MX+B OFF

6. Any range button will to&e the display to the alternate

MX+B status. Therefore, press a Range button and the

following message will be displayed:

MX+B ON

7. With the message “MX+B ON” displayed, press the

ENTER button to enable MX+B. The ins&rnent will

return to the function initially set.

8. AU subsequent readings cr) wiJ.l be the result of the equa-

tion: Y=MX+B.

Notes:

1. The hIX+B feature can be disabled by again running Pro-

gram 4. While in the progxwn, press a range button un-

til the message “MX+B OFF” is displayed and then press

the ENTER button.

2. Once h4X+B has been enabled, the Model 196 will show

the value of Y. If the value of Y is larger than can be

handled by the particular range, the overrange message

will be displayed, indicating the instrument must beswit-

ched to a higher range.

3. User selected values of M and B will be stored within

the Model 196 until the power is turned off (unless saved

by Program 30). These constants will be used whenever,

X+B is enabled. Note however, that the value of B is

scaled according to the range in use. Example: A value

of 19.00000 entered for B is actually 19.0000OV with the

instrument on the 30V range and 19O.OOOOV with the in-

strument on the 3OO.oMxxT range.

4.An example of readings that will be obtained when

MX+B is enabled is shown in Table 2-8. Each of the ob-

tained values for Y assumes the following constants:

M=+1.5; B=+5.

Table 2-8. Example MX + B Readings

lzooomc

~-2.5OOOOvDc

14.4500OVAC

11.00000kQ

*where M = +1.5 and B = +5.

2.7.4 Program 5 (HI/LO/Pass)

Program 5 is used to enable the HI/LO/PASS program. With

this program, the Model 196 will indicate whether or not

a specific reading falls within a prescribed range. The fac-

tory defa&L.Q limit is a negative full scale reading, with

the actual value depende~ntron function and range. Con-

versely, the factory’default y limit is a positive full scale

reading. With these f full scale limits, the Model 196 will

display the HI or Lo message for overrange readings and

the PASS message for oh-range readings. The HI and LO

limits can be set to any on-range value with Program.35

(HI/Lo Limits).

This feature is especially useful for component evaluation,

where certain component tolerances must be observed.

Once the limits are programmed into~ the instrument, the

operator need only monitor the display messages to deter-

mine the integrity of the device. perform the following pro-

ceduIe to enable Program 5:

1. Select the desired function and range, and zero the in-

shument, if desired. These operating parameters can-

not be changed once the program is active without ex-

iting the program.

2. If the limits need to be checked or changed, do so using

Program 35.

3. Press the PRGM button. The following prompt will be

displayed:

PROGRAM ?

4. Enter the number 5 by pressing the “5” button. The

following message will be displayed briefly:

HI LO PAS5

2-19

BASIC DMM OPERATION

5. At this point, the instrument will run the program. No

numeric readings wilI be displayed. Instead, one of the

following messages will be displayed:

A. If the measured value is less than the low limit, the

following message will be displayed:

B. If the measured value is greater than the Mgh limit,

the following message will be displayed:

C. If the measured value falls within the high and low

limits, the following message will be displayed:

PASS

6. To disable the program, press the function button that

has the indicator light on. This will disable the~prZ@am

without changing the measurement parameters (i.e.

function, range, etc.) of the instrument.

Notes: ~~~~ ~~~ >)

1. L&its can be set using Program 35 with or without Pro-

gram 5 enabled.

2. User selectable values of L and H will be stored within

the Model 196 until the power is turned off (unless saved

by Program 30). These constants will be used whenever

HI/LO/PASS is enabled. Note however, that the value of

L and H are scaled according to the range in use.

3. Pressing any ofthe front panel controls, &cept dB (unless

in AC), ENTER, and LOCAL, will disable the program

and select the feature associated with that button.

2.7.5 Program 6 (Multiplexer, Auto/Cal)

The multiplexer autoical routines may be defeated by run-~

ning Program 6. Using the Model 196 with the auto zerokal

defeated increases measurement speed and is useful for

making high impedance DC voltage measurements which

can be affected by the input multiplexing. Perform the

following steps to run this program: -.

1. Press the PRGM button. The following prompt will be

displayed:

PROGRAM ?

2. Enter the number 6 by pressing the “6”button. The cur-

rent multiplexer status will then be displayed. For exam-

ple, if the multiplexer is on, the following message~~*

be displayed: ~;~

MUX ON

3. If the alternate multiplexer status is desired, press one

of the range buttons. The alternate status will be

displayed as follows:

MUX OFF

4. To enter the displayed multiplexer status, press the

VENTER button. The instrument will return to the

previous operating state.

NOTE

with the auto/Cal multiplexer disabled, the internal

zero and calibration are affected by changing the

nominal inout level. esneciallv on ohms and the

3OOVDC range. WheneGer the’applied input level

changes, press the selected function button to per-

form an auto/Cal routine, otherwise substantial

errors will result. Zero and calibration may also be

affected by time. Thus, it is recommended that the

selected function button be pressed periodically.

2.7.6 Program 3O~(Save)

Program 30 saves current instrument conditions set up by

the user. These user programmed conditions will then

replace the previously saved default conditions on power

up. Also, an SDC or DCL asserted over the IEEE-488 bus

will return the instrument to these saved conditions.

The following instrument operating parameters are saved

by this program:

Function

Range

Resolution

Zero status (on/off) and value

Filter status (on/off) and value

ACdB status (on/off) and reference value

IEEE ~address ~.~

Line frequency setting

MX+B status (on/off) and values

HI&O limits

Ohms compensation status (on/off)

Perform the following procedure to use the save program:

1.~ Seth up the instrument as desired or~run Program 37

(Reset) to return the instrument to the factory default

conditions.

2-20

BASIC DMM OPERATION

2. Press the PRGM button. The following prompt will be

displayed: 3. Ifit is desired to retain the displayed status value, proceed

to~step 4. To change the status value, enter the address

number (0 to 30).

PROGRAM ? 4. With a valid status disulaved, mess the ENTER button.

3. Enter the number 30 by pressin the “3” and “0” but-

tons. The following message & be displayed briefly:

The instrument will %rn to the previously defined

,stam

SAVE

4. The following message will then be displayed:

ENTBR?

Notes:

1. If an invalid number is entered, the instrument wiIl exit

zrn@t$ program with the IEEE primary address being

5. To save the instrument set up conditions, press the 2.To change the default address of the instrument, select

ENTER button. The following message v$k~displayed the desired IEEE address using this program and then

L..z^cL.. Program 30 (or Ll over the IEEE bus) to save it. Cvchng

BNTBRBD

power, Program 37 (Reset), or an SDC, DCL or Lb sen?

over the bus will not have any affect on the new default

address.

6. The instrument wi!.l return to the conditions set up in 3. If the JEBE address is changed but not saved:

step 1 and will now power up to those conditions. A. 2 cl&power will return the insmument to the default

B .

B. Program 37 (Reset), or an SDC or DCL sent over the

Notes: bus wiB not have any affect on the current address.

1. TO exit the program without changing the previous C. Sending LO over the bus will not change the current

default conditions, press any front panel button except IEEE address, and will save that address as the power

the ENTBR button. The instrument will return to the up default address.

operating states set up in step 1. 4, An /mCAfJ’ error d default the IEEE address to 7 and

2. To return the instmment to the factory power up default the line frequency setting to 6OHz.

conditions, use Program 37 (Reset) and save the condi-

tions using Program 30. ~~ 2,7.8 Program 32 (Lht? Frequency)

3. When using this program, make sure that the rest~of the

instrument is in the desired operating state. The Model I.96 does not automatically detect the power line

frequency upon power up.~~This program aLlows the user

2.7.7 Program 31 (IEEE Address) to check the line frequency set

to select the alternate fmquenc$K&%e&Z%Z~~~

Program 31 allow? the user to check and/or modify the ad- to either 5OH.z or 6oHz. Perform the folloxjng steps to check

dress of the IEEE&B interface. The interface can be set to and/or change the line frequencysetting of the yodel 196.

address from 0 to 30 Detailed information on

!!Zo%g%ps to use this program:

bus rs prowded m Section 3. Perform the 1. Press the PRGM button. The following prompt will be

displayed.

PROGRAM ?

1. Press the PRGM button. The following prompt will be

displayeyed: 2. Enter the number 32 by pressing the “3” and “2” but-

tons. The current line frequency setting will then be

PROGRAM ? displayed. J.f the instrument is currently set to 6OH.2, the

2. Enter the number 31 by pressing the “3” and “1” but- following message @I be displayed:

tons. The IEEE address value will be displayed. Exam- PRBQ=6OHz

pie: If the current primary address of the instrument is

7, the following message will :be displayed:

07 IE

2-21

BASIC DMM OPERATION

3. If the displayed frequency setting matches the available

line frequency, proceed to step 4. If the alternative line

frequency setting is needed, press one of the Range but-

tons. The display will toggle to the alternate frequency

setting as shown:

FREQ=5OHz

4. With the correct frequency setting displayed, press the

FJITER button. The instrument will return to the pre-

vious operating state.

Notes:

1. To change the default line frequency setting of the ins&~-

ment, select the desired setting using this prog;&% and

then Program 30 (or Ll over the IFEE bus) to save it. Cycl-

ing power, Program 37 (Reset), or an SDC, DCL or I.0

sent over the bus will not have any affect on the new

default setting.

2. If the line frequency setting is changed but not saved:

A. Cycling power, x~r sending an SDC~or DCL over the

bus will return the instrument to the default.s&&.

8. Program 37 (Reset) will not have any affect on the cur-

rent setting.

C. Sending Lo over the bus will not change the current

line frequency setting, and will save that setting as

the default setting.

3. An “UNCAE’ error will default the IEEE address to 7 and

the line frequency setting to 6OHz.

2.7.9 Program 33 (Diagnostic)

Program 33 is a diagnostic program designed to switch on

tious switching PET’s, relays and logic levels to allow sig-

nal tracing through the instrument. Also, tests on the dis-

play and memcry are performed. Refer to paragraph 6.7.3 in

the maintenance section to use this program to troubleshoot

the instrument.

2.7.10 Program 34 (MX+B Parameters)

This prqpm allows the operator to check/change the M

and B values for the MX+B feature (Program 4) of the

Model 196. The factory

lBOOOOO and the value of i. ower up default value of M is

1s OOOOCKX. To check/change the

values of M and B, proceed as follows:

1. Press the PRGM button. The following prompt will be

displayed:

PRO&AM ?

2. Enter the number 31 by pressing the “3” and ‘+I” buttons.

The current value of M will now be diip1ayed.X thefac-

tory default value is the current value of M, then the

following message will be-displayed:

l.OLlONO M

3. If it is desired to retain the displayed M value, proceed

to step 4. If it is desired to modify the M value, do so

causing the data buttons. Note that valid M values are in

the range of -9.999999 to +9.999999.

4. With a M value displayed, press the ENTER button.

5. The ctit%t~B value will now be displayed. If the factory

defualt~value is the current B value, the following

message will be displayed:

0000.000 B

Decimal point~position is determined by the mnge that

the instrument was on when t&s program was selected.

6. If it is desired to retain the displayed B value, proceed

to step Z If it is desired to modify the value of M, do

so usin

fmm f % the data keys. Notes that the B value range is

.ooolxlo-~ to i9999.999 (in&ding zero).

7. With a valid B value displayed, press the ENTER but-

ton. The instrument will return to the previously defm-

ed state of operation.

Notes:

1. User se&ted &&s of M and B will be~st&ed &thin

the Model 196 until the power is turnedoff (unless saved

by Program 30). These constants will be used whenever

MX+B is enabled. Note however, that the value of B is

scaled according to the range in use. Example: A value

of 19.00000 entered for B is actually 19.O0XOV with the

instrument on the 3OV range and 19O.OOC0V with the in-

strument in the 300V range.

2. The user can set the values for M and B as the power

up default values by running Program 30.

2.7.11 Program 35 (Hi/LO Limits)

Program 35 is used to set the high and low limits for t&

HI/LO/PASS program (l’rogram 5). The fa~ctory default

limits are +303X03 counts (Hl limit) and -3030300 counts

(LO limit). The actual value of the limits is dependent on

the range. For example, the factory default HI limit on the

3V ran e is 3.03OOoW, while the factory default HI limit ori

the3c8 range 1s 30.3ooo(N. Perform the following procedure

to~set HI and Lo limits:

2-22

BASIC DMM OPERATION

1. Place the Model 196 in the function and range that the

HI/LO/PASS program (Program 5) will be used.

2. Press the PRGM button. The folIowing prompt will be

displayed:

PROGRAM ?

3. Enter the number 35 by pressing the “3” and “5” but-

tons. The current LO limit wiII be displayed. For exam-

ple, if the I.0 limit is the factory default value, the follow-

ing message will be displayed:

-303.0000 Lo

Decimal point position is determined by the range that

the instrumentwas on when this program was selected.

4. If it is desired to retain the dis

to step 5. Otherwise, modify t

layed LO limit, proceed

e &splayed value using

the data buttons. The IO limit must be in the range of

-3030000 to +3030000 counts.

5. With the desired LO lit displayed, press the ENTFR

button. The current HI limit will be~dis la ed. For ex-

ample, if the LO lit is the factory d &I? a t value, the

following message will be displayed:

303.0000 HI

Decimal point position is determined by the ran e that

the instrument was on when this program was se e&d.

6. If it is desired to retain the displayed HI limit, proceed

to step 7. Otherwise, modify the displayed value using

the data buttons. The HI limit must be in the~range of

-3030000 to +3030ooo counts.

7. With the desired HI limit displayed, press the ENTER

button. The instrument will return to the previous

operating state.

Notes:

1. Userselected limits wiil be stored in the Model.196 until

power is turned off (unless saved by Program 30). These

constants will be used whenever Program 5

@I/IAX?~SS) is enabled.

2. Limits set by the user will become the power up default

limits by running Program 30 (Save).

3. Entering an invalid value will result with the instrument

using the power up default limit.

2.7.12 Program 36 (Calibration)

The user can easiIy perform front panel digital calibration

by applying accurate calibration signals using Program 36.

The calibration signals can be either prompted default

values or numbers entered from the front panel. Paragraph

6.4.5 descriis the basic steps for using this program, while

paragraphs 6.4.7 through 6.4.12 provide the complete front

panel calibration procedure.

2.7.13 Program 37 (Reset)

Program 37 resets instrument set up parameters back to fac-

tory default conditions. The factory default conditions are

listed in Tables 2-l and 3-T’. Perform the following steps to

run this program.

1. Press the PRGM button. The following prompt will be

displayed:

PROGRAM ?

2. Enter the number 37 by pressing the “3” and “7” but-

tons. The following message will be displayed briefly:

RESET

3. The following promptwill then be displayed:

4. Press the ENTER button. The following message will be

displayed briefly and the instrument~will return to the

factory default conditions.

ENTERED

Notes:

1. Prwgram 37 (Reset) can be aborted by pressing any front

panel button, except the ENTER button, when the

prompt “ENTER?” is displayed. The instrument will

return to the previous operating state.

2. Once the instrument is reset to the factory default con-

ditions with this program, Program 30 must be run if

it is desired to have the factory default conditions on

subsequent power ups.

3. Program 37 (Reset) will have no aifect on the current ISEE

address and line frequency setting.

2-23

SASIC DMM OPERATION

2.7.14 Program L!

The ohms offset compensation program is used to compen-

sate for voltage potentials (such as thermal EMFs) across

the resistance to be measured. This feat&s can be used for

both 2-terminal and 4-terminal resistor measurements up

to 3OkR. Additional information on ohms offset compen-

sation can be found in paragraph 2.6.6. Perform the follow-

ing steps to use the ohms offset compensatron program:

1. Press the PRGM button. The following prompt wilJ be

displayed:

PROGRAM ?

2. Press the Q button. The current status of ohms compen-

sation wiIl be dis

is currently disa

E layed. For example, if compensation

displayed: led, the following messages will bee

COMPOFF

3. If the alternate status is desired ,gressoneoftheRange

buttons. The alternate status will e displayed as fo!.lows:

COME’ ON

4 With the desired compensation status displayed, press

the ENTER button.

A. If ohms offset compensation was enabled, the instru-

ment will be placed in the ohms function with the

0 indicator light flashing.

B. If ohms offset compensation was disabled, the insnu-

ment will return to the previous 0

the ohms function is selected, K .’

eraling state. When

will not flash. e B mdrcator light

Notes:

1. The lT iridicator~light reveals the status of ohms offset

compensation. With the ohms function selected, a

flashing 0 light indicates that compensation is enabled,

and conversely, a non-flashing Q light indicates that com-

pensation is disabled.

2. The status of ohms offset compensation can be saved as

a power up default condition by running Program 30.

2.7.15 Program ZERO

Program ZERO allows the user to check or modify the,,zero

value. A complete explanation of the zero modifier can be

found in paragraph 2.6.2. Once a zero v&e is set on a

measurement function, that zero level is the same on all

the ranges. Example: If 1V DC is set to the zero value of

the 3V DC range, the zero value in the program wiil be

displayed as 1.000000. On the 30V DC range the zero value

will still be 1V DC, but will be expressed as 01.00000 in the

program.

Perform the following procedure to implement Program

ZERO.

1. Press the PRGM button. The following prompt will be

displayed:

PROGRAM ?

2. Press the ZERO button. The current zero value will then

be displayed. Example: If the instrument is on the 3OV

DC range and the current zero value is +3V DC the

following message will be displayed:

03.00000 z -~

3. If it is desired to retain the displayed zero value, press

the ENTER button. The instrument will return to the

previous operating state with the zero modifier enabled.

The displayed reading will reflect the entered zero value.

4. To modifythe zero value, enter the new value and press

the ENTER button. The instrument will return to the

previously defined state with the zero modifier enabled

using the newly entered zero value.

Note: The factory default power up zero value is OCKKICO.

If it is desired to have a different zero value displayed

on power up, modify the zero value using Program

ZERO followed by Program 30 to save it.

2.7.16 Program FILTER

Program FILTER allows the user to modjfy~ the weighting

of the digital filter. Valid filter values are from 1 to 99. More

information concerning the filter can be found in paragraph

2.6.3.

Perform the following steps to check and/or modify the

filter value.

1. Select the desired function.

2. Press the PRGM button. The following prompt will be

displayed:

PROGRAM ?

2-24

BASIC DMM OPERATION

3. Press the FIITER button. The current filter value will then

be displayed. Example: If the filter value is 5, the follow-

ing message wilI be displayed:

05 F

4. If it is desired to retain the displayed filter value, pro-

ceed to step 5. If it is desired to modify the filtervalue,

do so using the data buttons.

5. With the desired filter value displayed, press the ENTER

button. The instrument will return to the previously

defined state when the filter is enabled.

6. To check or change the filter value of another function,

select the function and repeat steps 2 through 5.

Notes:

l.The factory default power up filter value is 10. If it is

desired to have a different filter value on power up,

change the filter value using Program FILTER followed

by Program 30 to save it.

2. Entering a filter value of 00 wilI default the filter value

back to the previous value and return the instrum~ent~to

the previously defined state with the filter disabled.

2.7.17 Program dB

Program dB allowsthe user to check and/or modify~the dB

reference. The programmable voltage reference can be up

to 9999999V and the

be up to 9.99Y999mA. ?I

rogr-able current references can

et&d information on dB messure-

ments is provided in paragraph 2.6.9. Perform the follow-

ing steps to use this program:

1. Press the PRGM button. The following promptwiIl be

displayed:

PROGRAM ?

2. Press the dB button. The current reference level will be

displayed. Example: If the reference is 1V or lmA, the

following message wilI be displayed:

1.oocmoodB

3. Modify, if desired, the dB reference level and press the

ENTER button. The recommended reference mnge is

lo/# to 9.999999V and l!lnA to 9999999mA. The ins&u-~

ment wilI return to the previously defined state.

ENTERED

Note: The factory default power up voltage reference is

1.OOOOOOV with the instrument in ACV and 1M)OOOOmA

with ACA selected. If it is desired, to have a~ different

referencepn power up, modify the reference using Pro-

gram dB followed by Program 30 to save it.

2.8 FRONT PANEL TRIGGERING

With the instrument properly configured over the IEEE-488

bus, readings can be triggered from the front panel using

the ENTER button. The following paragraphs provide

general procedures for one-shot front panel triggering and

front panel triggering into data store.

NOTE

The procedures in this section require IEEE-488 bus

programming. Refer to Section 3 particukxly

paragraphs 3.9.7 (Triggering) and 3.9.9 (Data Store)

fx$t& on progrsmming the instrument over the

On power up, the instrument is in the continuous trigger

mode with the conversion rate determined by the internal

time base. To lace the instrument in a state where each

press of the Ed OR button wilI trigger one reading, per-

XJTE

form the following general procedure:

1. ~Place the instrument in the desired function and range.

2. mace the instrument in “one-shot on external trigger” by

sending ‘I7 over the IEEE-488 bus.

3. Press the LOCAL button to return control to the front

pill-d.

4. Each press of the ENTER button will trigger one reading.

2.8.2 Triggering Readings into Data Store

The front panel ENTER button can be used to trigger

reading into data store. In the one-shot trigger mode, each

ress of the ENTERbutton wilI store one readin

E lf in the

uffer In the continuous trigger mode, the ENTE button

will start the storage process at the rate that was programm-

ed over the IEEE-488 bus. Performthe following general

procedure to trigger readings into data store from the front

panel:

1. Place the instrument in the desired function and range.

2. place the instrument in the appropriate trigger mode:

A. To store one reading in the buffer after each press of

the ENTER button, send T7 (one-shot on external trig-

ger) over the bus.

B. To store a series of readings in the buffer after the

ENTER button is pressed, send~T6~(continuous on CC-

ternal trigger) over the bus.

2-25

3. Configure the storage interval and buffer size of the data

store by sending the appropriate Qn and I commands

over the bus (see paragraph 3.9.9).

4. Press the LOCAL button to return control to the front

panel.

5. Press the ENTER key to either store one reading in the

buffer or to start storage of a series of readings.

2.9 EXTERNAL TRIGGERING

The Model 1% has two external BNC connectors on the

rear panel associated with instrument triggerinp. The EX-

TERNAL TRIGGER IiWUT connector allows the instru-

ment to be triggered by other devices, while the

VOLTMETER COMPLETE OUTPUT connector allows the

instrument to triggerother devices.

2.9.1 External Trigger

The Model 196 may be triggered on a continous~ or one-

shot basis. For each of these modes, the trigger stimulus

will depend on the selected trigger mode. In the continuous

trigger mode, the instrument takes a continuous series of

readings. In the one-shot mode, only a single reading is

taken each time the instrument is triggered.

The external trigger input requires a fallin

‘ITL logic levels, as shown in Figure 2-8. edge pulse at

Ebb omaections to

the rear nanel !?XTERNAL TRIGGER INPUT iack should

be made with a standard BNC connector. If thei&rument

is in the external trigger mode, it will be triggered to take

readings while in either a continuous or one-shot mode

when the negative-going edge of the external trigger pulse,

OCCUIS.

TRIGGERS ON

LEADING EDGE

Figure 2-8. External Trigger Pulse Specifications

To use the external trigger, proceed as follows:

1. Connect the external trigger soum to the rear panel BNC

EXTERNAL TRIGGER INPUT ccinnector. The shield

(outer) part of the connector is connected to digital com-

mon. Since an internal pull-u ~re.?.istor is used, a

mechanical switch ma be used.

bcmncing circuitry wiEyprobably l! required to avoid im-

ate however that de-

proper &&e&g.

CAUTION

Dq not exceed 30V between digital common and

chassis ground, or instrument damage may

occur.

2. Place the instrument in the “one-shot on external trig-

ger” (T7) or “continuous on external trigger’ (T6) as ex-

plained in paragraph 3.9.7.

3. To trigger the instrument, apply a pulse to the external

trigger input. The instrument twill process a single

reading each time the pulse is applied (one-shot), or start

a continuous series of readings.

Note: External triggering can be used to control the fill rate

in the data store mode with the data store enabled and one-

shot mode selected, each trigger will cause a reading to be

stored.

2.9.2 Voltmeter Complete

The Model 196 has an available output pulse that can be

used to trigger other instrumentaticm. A single TTL

compatible negative-going pulse (see Figure 2-9) will ap-

pear at the VOLTMETER COMPLETE OUTPUT jack each

time the instrument completes a reading. To use the

voltmeter complete output, proceed as follows:

1. Cmnect the Model 196 to the instrument to be triggered

with a suitable shielded cable. Use a standard BNC con-

nector to make the connection to the Model 196.

CAUTION

Do not exceed 30V between the VOLTMETER

COMPLETE common (outer ring) and chassis

ground or instrument damage may occur.

2-26

BASIC DMM OPERATION

2. Select the desired function, range, trigger mode, and

other operating parseters, as desired.

3. In a continuous trigger mode, the ins@unent will out-

put pulses at the conversion rate; each pulse will occur

after the Model I% has completed a conversion.

4. In a one-shot trigger mode, the Model 196 will output

a pulse once each time it is higgered.

REA?&JG BEGIN NEXT

CONVERSION

Figure 2$X Uses shielded cables with BNC connectors.

The Model 196~YOLTMETER coMrmouTr~jack

should be connected to the Model 705 EXTERNAL TRIG

GER INPUT jack. The Model 196 EXTEXNALTRIGGEE

INPUT jack should be connected to the Model 7Ki

CHANNEL READY OUTPUT. Additional connections,

which are not shown on the diagram, will also be

necessary to apply signal inputs to the scanner cards,

~~~

1’

as well as for the signal lines between the wanner and

the Model 196.

2. Place the Model 196 in “one-shot on external trigge~” 0

as explained in paragraph 3.9.7.

3. Program the Model 705 scan parameters such as first and

last channel as required. Place the instrument in the

single scan mode.

LS TTL LOU 1

(025V TYPICAL) 1

I I

Figure 2-9. Voltmeter Complete Pulse

4. lnstdl the desired scanner cards and make the re uired

input and output signal connections. See the MO

i el705

Instruction Manual for details.,

5. Begin the measurement sequence by pressing the Model

705 START/STOP button. The Model 705 will close the

first channel and trigger the Model 196 t0 t&e a reading.

When the Model 196 completes the reading, it will hig-

ger the Model 705 to go to the next channel. The pro-

cess repeats until all programmed channels have been

Specifications scanned.

2.9.3 Triggering Example

As an example of using both the external trigger input and

the meter complete output, assume that the Model 196 is

to be used in conjunction with a Keithley Model 705 Scan-

ner to allow the Model 196 to measure a number of dif-

ferent signals, which are to be switched by the scanner. The

Model 705 can switch up to 20 2-pole channels (20 single-

pole channels with special cards such as the low-current

card). In this manner, a single Model 196 could monitor

up to 20 measurement points.

By connecting’the triggering inputs of the two instruments

L__..,- ~~~

cogerner, a complete automatic measurement sequence”

could be performed. Data obtained from each measurement

point could be stored using the data store of the Model 196.

Once the Model 705 is programmed for its scan sequence,

the measurement procedure is set to begin. When the

Model 705 closes the selected channel, it triggers the Model

705 to scan to the next channel. The process repeats until

all channels have been scanned.

\I I /I

MOOEL 705 I

(I II

MODEL 196

To use the Model 1% with the Model 705, proceed as

follows:

1. Connect the Model 196 to the Model 705 as shown in Figure 2-10. External Triggering Example

2-271248

SECTION 3

IEEE-488 PROGRAMMING

3.1 INTRODUCTION 3.7

This section contains information on programming the

Model 196 over the IEEE-488 bus. Detailedinstructions fork

all programmable functions are included; however, infor-

mation concerning operating modes presented elsewhere

is not repeated here.

3.8

Additional IEEE-488 information is provided in the follow-

ing appendices:

Appendix A-ASCII character codes and multiline inter-

face command messages.

Appendix B-Progmmning information for using the FM

PC/XT computer with the Model 8573A interface.

Appendix C-Saniple programs using a variety of ef!rent

controllers with the Model 196.

3.9~

3.10

3.11

Appendix D-A detailed overview of the IEEE488 bus. 3.2 A SHORT-CUT TO IEEE-488 OPERATION

Also, a tear out card listing the device-dependent com-

mands follows the appendices.

S&ion 3 contains the following infonnation:~ ~_~~~ ~:

The paragraphs below will take you through a step-by-step

procedure to get your Model 196 on the bus as quickly as

possible and program basic operating modes. Refer to the

remainder of S&ion 3 for detailed information on IEEE-488

operation and programming.

3.2 A Short-cut to IEEE-488 Operation: Gives a

simple step-by-step procedure for g+ng on the bus

as quickly as possible. Step 1: Connect Your Model I96 to the Controller

3.3 Bus Connections: Shows typical methods for con-

necting the instrument to the bus.

34 Interface Function Codes: Defies IEEE standard

codes that apply to the instrument.

With power off, connect the Model 196 to the IEEE-488 in-

terface of the controller using a standard interface cable.

Some controllers such as the HI-85 include an integral

cable, while others require a separate cable. Paragraph 3.3

discusses bus connections in more detail.

3.5 Primary Address Selection: Tells how to program

the instrument for the correct primary address. Step 2: Select the Primary Address

3.6 Controller Programming: Demonstrates simple

programming techniques for a typical IEEE-488

controller.

Much like your home address, the primary address is a way

for the controller to refer to each device on the bus in-

dividually. Consequently, the primary addres~s of your

Model 196 (and any other devices on the bus, for that mat-

Front Panel Aspects of- IEEE-488 Operation:

Describes the operation of the LOCAL key and bus

status indicators, and summarizes front panel

messages that may occur during bus operation.

General Bus Command Programming: Outlines

methods for sendingg&&al bus commands to the

instrument.

Device-Dependent Commands: Contains descrip-~

tions of most of the programmjng commands used

to control the instrument over the bus.

Using the Translator Mode: Describes an alternate

Prow naming method of using easily recognized

user-defined words in place of device-dependent

xommands.

Bus Data Transmission Times: Lists typical times

when accessing instrument data over the bus.

3-l

IEEE-488 PROGRAMMING

ter), must be the same as the primary address specified

in the controlletis programming language, or you will not

be able to program instrument operating modes and ob-

tain data over the bus. Keep in mind that each device on

the bus must have a different primary address.

The primary address of your Model 196 is set to 7 at the

factory, but you can program other values between 0 and

30 by pressing PRGM, 3, 1, and then using the data en*

keys to change the primary address. Once the desired value

is displayed, press ENTER to program the value.

More detailed information on primary address selection is

located in paragraph 3.5.

Step 3: Write Your Program

Even the most basic operations will require that you write

a simple program to send commands and read back data

from the instrument. Figure 3-l shows a basic flow chart

that a typical simple program will follow. The programming

example below follows this general sequence. This program

will allow you to type in command strings to program the

instrument and display data on the computer CRT.

HP85 Progra mming Example-Use the simple program

below to send programming commands to the Model 196

and display the data string on the computer CRT.

PROGRAM COMMENTS

10 REMOTE 707 Send remote enable.

26 DISP L L COMMAND’ ’ j Prompt for command

30 INPUT CB

40 UUTPUT707; CB

string.

Input the command string.

Send command string to

196

50ENTER707; A$ Get a r&ding from the

inshument.

OPERATING

REQUEST DATA

END

60 DISP A8

70 GOTO 20

80 END

~Diiplay the reading.

Repeat.

3-2

Step 4: Pmgram Model I.96 Operating Modes Step 5: Get Readings from the Model I96

You can program instrument operating modes by sending Usually, you will want to obtain one or more readings from

the appropriate command, which is made up of an ASCII

letter representing the command, followed by one or two the Model 196. In the example program abcwe, a single

reading is requested and displayed after each command.

numeric parameters separated by commas for the corn-~ In other cases, you may wish to program the instrument

mand option. Table 3-l summarizes the commands used configuration& the beginning of your program, and then

to select function and range. obtain a whole series of measurements.

A number of commands can be grouped together in one The basic reading string that the Model 196 sends over the

string, if desired. Also, you must terminate the command bus is in ASCII characters of the form:

or command string with the X character in order for the

instrument to execute the commands in question. NDCV-l234567E+O

If you are using the programming example from Step 3 where: N indicates a normal reading (0 tiould indicate an

above, simply type in the command string when prompted overflow),

to do so. Some example strings are given below. DCV shows the function in effect (in this case, DCV)

-1.234567 is the mantissa of the reading data,

E?-0~ represents the exponent.

F3X: select DCA function.

FORZX: select DCV function, 3V range.

Table 3-1. IEEE-488 Commands Used to Select Function and Range

:ommand I

Execute other device-dep$w~commands.

DC volts

AC volts

ohms

DC current

AC current

ACV dB

ACA dB

Offset compensated ohm.~~-

Offset Compensated

WY Aa’ ~~!lF!K ACA Ohms ACV dB, &CA dB Ohms

Auto Auto Auto Auto Auto Auto Auto Auto

300mV 3oOmV 3OOfi 300~2% 300 0 Auto Auto 300 I-i

3v 3v 3mA 3mA 3k0 Auto Auto 3kt-l

30 V 30 V 3OmA 30mA 30 kQ Auto Auto 3Ok’2

300 v 300 v 3oomA 3ooti-TLiO~kQ Auto A&o 30 lit-l

300 V 300 V 3 A 3 A 3Mfl Auto Auto 30 kfl

300 V 300 V 3 A 3 A 3OM!l Auto Auto 30 kQ

300 V 300 V 3 A 3 A 3OOMfl Auto Auto 30, kQ

3-3

3.3 BUS CONNECTIONS

The Model 196 is intended to be connected to the IEEE-488

bus through a cable equipped with standard IEEE-488 con-

nectors, an example of which is shown in Figure 3-2. The

connector is designed to be stacked to allow a number of

parallel connections at one instrument;~~Two screws are

located on each connector to ensure that connections re-

main secure. Current standards call for metric threads,

which are identified with dark colored screws. Earlier ver-

sions had different screw& which were silver colored. Do

not attempt to use these type~~of connectors tin the Model

196, which is~aesigned for metric threads.

Figure 3-2. IEEE-488 Connector

INSTRWENT INSTRUMENT

CONTROLLER

Figure 3-3. IEEE-488 Connections

Connect the Model 196 to the IEEE-488 bus as follows:

1. Lime up thecable connector with the connector located

on the rear panel of the instrument. The connector is

designed so that it will fit only one way. Figure 3-4 shows

the location of the IEEE-488 connector on the instrument.

2. lighten the saew securely, but do not overtighten them.

3. Add additional connectors from other instruments, as

required.

4. Make certain that the other end of the cable is properly

connected to the controller. Most controllers are

equipped with an IEEE-488 style connector, but a few

may require a different~ type of connecting cable. Con-

sult the instruction manual for your controller for the

. . _..

A typical connecting scheme for a multiple-instrument test

set up is shown in Figure 33. Although any number of con-

nectors can be stacked on one instrument, it is recommend-

ed that you stack no more than three connectors on any

one unit to avoid possible mechanical damage.

proper connectmg metnoa.

3-4

IEEE-488 PROGRAMMING

ADDRES3ENTEREDWiTH

FRONT PANEL PROGRAM 31

FIgure 3-4. IEEE-488 Connector Location

NOTE

The FEE-488 bus is limited to a maximum of 35

devices, incluiing the controller. The maximum

cable length is 20 meters, or 2 meters times the

number of devices, which ever is less. Failure to

observe these limits may result in erratic bus

operation.

Table 3-2. IEEE Contact Designation

contact IEEE-488

Number Designation

1 DIOl

; D102

D103

4 DI04

7 N-RFD

i NDAC

11 ATN

tz SHIELD

DI05

14 D106

E D107

DI08

20 Gnd, (8)*

ii Gnd, (9)

Gnd, (lo)*

23 Gnd, (ll)*

24 Gnd. LOGIC

Tyge

Data

Management

Handshake

Management

Ground

Data

Management

Ground

Giounii

Ground

*Numbersin parentheses refer to signal ground rehrn

Custom cables may be constructed by using the informa- of reference-d contact number. EOI and REN signal

fiOn in Table 3-2 and Figure 3-5. Bble 3-2 Ii& the COntad lines return On contact 24.

assignments for the bus, and Figure 3-5 shows the contact

3.4 INTERFACE FUNCTION CODES

CAUTION

IEEE-488 common is connected to chassis

ground and cannot be floated.

CONTACT 12

-7 r CONTACT I

t I J

I \

CONTACT 241 L CONTACT 13

Figure 3-5. Contact Assignments

The interface function codes, which are part of the IEEE-488

standards, define an instmment’s ability to support various

interface functions, and they should not be confused with

programming commands found elsewhere in this manual.

Interface function codes for the Model 196 are listed in Table

3-3 and are listed for convenience on the rear panel adja-

cent to the IEEE488 connector. The codes define Model 196

capabilities as follows:

SH (Source Handshake)-SHl defines the ability of the

Model 196 to properly handshake data or command bytes

when the unit is acting as a source.

AH (Acceptor Handshake&AH1 defines the ability of the

Model 196 to properly handshake the bus when it is ac-

ting as an acceptor of data or commands.

T (Talker)-The ability of the Model 196 to send data over

the bus to other devices is defined by the T function. Model

196 talker capabilities exist only after the instrument has

been addressed to talk.

3-5

L (Listener)-‘he L function defines the ability of the Model

196 to receive device-dependent data over the bus. Listener

capabilities exist only after the instrument has been ad-

dressed to listen.

SR (Service Request)--The SR function defies the ability

of the Model 196 to request services from the controller.

RL (Remote-Local)-The RL function defies the capabili-

gofe;vz Model 196 to be placed in the remote or local

PP (Parallel Poll)-I’he Model 196 does not have parallel poll-

ing capabilities.

DC (Device Clear)-The DC function defines the ability of

the Model 196 to be cleared (iitialized).

DT (Device Trigger)-The ability for the Model 196 to have

its readings triggered is defined by the DT function.

C (Controller)-The Model 196 does not have controller

capabilities.

TE (Extended Talker)-The Model 196 does not have extend-

ed talker capabilities.

LE (Extended Listener)-The Model 196 does not have SC-

tended listener capabilities.

E (Bus Driver Type)-The Model 196 has open-colle$or bus

drivers.

Table 3-3. Model 196 Interface Function Codes

Interface Function

Source Handshake cauabilitv

Acceptor Handshake capab&y

Talker (Basic talker, Serial poll, Unaddressed

to talk on LAG)

Listener (Basic listener, Unaddressed to listen

on TAG)

Service Request capability

Remote/Local capability

No Parallel Poll capability

Device Clear capability

Device Trigger capability

No Controller capability

Open Collector Bus Drivers

No Extended Talker capabilities

No Extended Listener capabilities-

3.5 PRIMARY ADDRESS SELECTION

The Model 196 must receive a listen cornman dbeforeitwill

respond to addressed co mmands over the bus. Similarly,

the instrument must receive a talk co mmand before it will

transmit its data. These listen and talk commands are de-

rived from the primary address of the instrument, which

is set to 7 at the factory. Until you become more familiar

with your instrument, it is recommended that you leave

the address at this value because the programming I+

amples in this manual assume the instrument is p10-

grammed for that address.

The primary address can be programmed for any value bet-

ween 0 and 30. However, each device on the bus must have

a unique primary address-- a factor that should be kept in

mind when setting the primary address of the Model 796.

Most controllers also use a primary address; consult the

controller instruction manual for details. Whatever address

is used, it must be the same as the value specified as part

of the controll& programming language.

To check the presently programmed primary address, or

to change to a new one, proceed as follows:

1. Press PRGM, 3,l. The current primary address will be

displayed. For example, if the current address is 7, the

following message will be displayed:

07 IE

2. To modify the address, key in a new value (O-30) with

the numeric data buttons.

3. With the desired address value displayed, press the

ENTER button. The address will be programmed and

the instrument wiU return to the previous operating state.

4. To store the address as the power up address, run Pro-

gram 30.

Note: For detailed information on using Programs 30 and

31, refer to paragraph 2.7.

3.6 CONTROLLER PROGRAMMING

A number of IEEE-188 controllers are available, each of

which has its-own programming language. In th$ section,

we will discuss the programming language for the Hewlett-

Packard W-85.

3-6

IEEE-488 PROGFlAMMlNG

NOTE

p=w amming information for using the IBM PC/XT

equipped with a Model 8573A IEEE-488 interface

is contained in Appendix 8.

3.6.1 Controller Handler Software

Before a specific controller can be used over the IEEE-488

bus, it must have IEEE-488 handler software installed. With

some controllers like the HP-85, the software is located in

an optional I/O ROM, and no software installation is

necessary on the part of the user. In other cases, software

must be loaded tioom a diskette and initialized, as is the

case with the Model 8573A interface.

Other small computers that can be used as IEEE-488 con-

trollers may not support all IEEE488 functions. With some,

interface pro* amming may depend on the particulsx in-

terface being used. Many times, little “tricks” are necessary

to obtain the desired results.

From the preceding discussion, the message is clear: make

sure the proper software is being used with the interface.

Often the user may incorrectly suspect that the hardware

is causing a problem, when it was the software all along.

3.6.2 BASIC Interface Programming

Statements

The progmmmin g instructions covered @ this section in-

clude examples written in HP-85 BASIC. This computer was

chosen for the examples because of its versatility in control-

ling the IEEE-488 bus. A partial list of statements for the

HP-85 is shown in Table 3-4.

HP-85 statements have a one or three digit argument~that

must be specified as part of the statement. The first digit

is the interface select code, which is set to 7 at the factory.

The last two digits of those statements requiring a 3-digit

argument specify the primary address. k the examples

shown, the default Model 196 address (7) is shown. For a

different address, you would of course change the cor-

responding digits in the programming statement.

Some~of the statements have two forms, with the exact con-

figuration depending on the command to be sent over the

bus. For example, CLEAR 7 sends a DCL command over

the bus, while CLEAR 707 sends the SDC command to a

device with a primary address of 7.

Table 3-4. BASIC Statements Necessary to Send

Bus Commands

Action 1 HP-85 Statement

Transmits string to device 7. OUTPUT707; A$

Obtain string from device Z ENTER707; A$

Send GTL to device Z LUCAL 707

Send SDC to device Z CLEAR 7’37

Send DCL to all devices. CLEhR 7

Send remote enable. REMOTE 7

Cancel remote enable. LrJCAL 7

Serial poll device Z SPOLL<707>

Send Local Lockout. LOCAL LOCKUUT

Send GET to device. TRIGGER787

Send IFC. ABURTIO 7

3.7 FRONT PANEL ASPECTS OF IEEE-488

OPERATION

The following paragraphs discuss aspects of the front panel

that are part of IEEE488 operation, including front panel

error messages, IEEE-488 status indicators, and the LOCAL

key.

3.7.1 Front Panel Error Messages

The Model 196 has a number of front panel error messages The Model 196 has a number of front panel error messages

associated with IEEE-488 programming. These messages associated with IEEE-488 programming. These messages

are intended to inform you of certain conditions that may are intended to inform you of certain conditions that may

occur when sendine device-deuendent commands to the occur when sendine device-deuendent commands to the

instrument, as summarized in Table 3-5.

The following paragraphs discuss each of these messages

in detail. Note that the instrument may be programmed

to generate an SRQ (paragraph 3.9.X3), and the Ul error

word can be checked for specific error conditions

(paragraph 3.9.16) if any of these errors occur.

3-7

IEEE-488 PROGRAMMlNG

Table 3-5. Front Panel IEEE-488 Messages

NO REMOTE Instrument programkd Wifh REN

false.

IDDC Uegal Device-dependent Command

IDDCO Illegal Device-dependent Command

Option

TRIG ERROR Instrument triggered while it is still

urocessinc a urevious triczer.

SHORT TIME &xume~t c&-mot Store G&dings at

programmed interval. Readings will

be stored as fast as the instrument

can run.

BIG STRING Programmed display message ex-

ceeds 10 characters.

CAL LOCKED Calibration command sent with

calibration switch in the disable

position.

CONFLICT Data Store-Instrument cannot store

readmgs at a high speed interval (1

to 14ms) while in an invalid state.

Storage will not occur.

Calibration-Calibration com&tid is

ignored when instrument is~ in a+ in-

valid state (i.e. dB function).

Note that the NO REMOTE Errol message is briefly

displayed when the second statement above is executed.

IDDC ilIIega.I Device-Dependent Command) Error

An IDDC error ocCtis when the unit receives an invalid

command over the bus. For -pie, the command string

EIX includes an illegal command because the letter E is not

part of the inshwmenl% programming language. When an

illegal command is received, the instrument will briefly

display the following enor message:

IDDC

To correct the error condition, send only valid commands.

Refer to paragraph 3.9 for device-dependent command pm-

gmmming details.

HP-85Rog? amming Fxampl~To demonstrate an IDDC er-

ror, use the following statements:

REMOTE 707

OUTPIJT 707; * ‘ElXI ’

Note that the IDDC error message is briefly displayed when

the second statement above is executed.

NOTE: Error messages associated with translator software

are located in paragraph 3.10. IDDCO (Illegal b&ice-Dependent Cmnman d Option)

Error

No Remote Error

Sending the instrument a legal command with an illegal

A no remote error will occur if the instrument receives a option that cannot be automatically scaled within bounds

device-dependent command and the REN (Remote Enable) will result in the following front panel error message:

line is false. In this instance, the following error message

will be displayed on the front panel: IDDCO

NO REMOTE For example, the command WX has an iIlegal option (9)

that is not paruf ~the instrument’s programming language.

The error condition can be corrected by placing the REN Thus, aleough~ the cq$rna$ (Y) itseg is valid, the option

line true before attempting to ~program the instrument. (9) is not, and the IDDCO err01 will result.

HP-85 Programming Example--To demonstrate the NQ To correct this error condition, use only valid command op-

REMOT!Z error message, type in &e following lines: lions, as discussed in paragraph 3.9.

LOCAL i

OUTPUT 707i L ( RiX’ ’ HP-85 Pm gmmming Example-Demonstrate an IDDCO er-

ror with the following statements:

3-8

IEEE-488 PROGRAMMlNG

REMOTE 707

OUTPUT 797; r r Y9X’ ’

Note that the IDDCO error message is briefly displayed

when the second statement above is executed.

Trigger Ovemm Error

A trigger overrun error occurs when the instrument receives

a trigger while still processing a reading from a previous

trigger. Note that orily the overrun triggers are ignored.

These overrun triggers will not affect the instrument ex-

cept to generate the message below. When a trigger over-

run occurs, the foLIowing front panel message will be

displayed for approximately one second:

TRIG ERROR

HP-85 Pro

gramming Example-To demonstrate~~~a trigger

overrun error, enter the following statements into the W-85

keyboard:

REMOTE 707

OUTPUT 707; 6 ‘ T3X’ ’

TRIGGERi07iZTRIGGER707

Note that the trigger overrun message is displayed after the

END LINE key is pressed a third time.

Big String Error

A big string error occurs when trying to &splay a message

(using the ED command) that exceeds 10 characters. Blank

display digits used in the message count~as characters. The

invalid message is ignored and the following message is

displayed briefly when a big string error occurs:

BIG STRING

HP-85 Progr amming Example-Enter the following state:

ments into the computer to demonstrate a big string qror:

REMOTE 707

OIUTPUT 707; r r DH0U@ARECYOU?X~ ’

When END LINE is pressed the second time the big string

error will occur because the message is made up oft I2

characters.

Cd Locked Error

A cal locked error occurs when trying to calibrate the in-

strument over the bus with the front panel calibration

switch in the disable position. Calibration commands will

be ignored and the following message will be displayed

briefly:

CAL LOCKED

Short Time Error

A short time error occurs when the instrument cannot store

readings in the data store at the programmed interval (Q

tiriunand). However, the instrument will continue to store

readings as fast as its can run. The following message is

displayed briefly when a short time error occurs:

SHORT TIME

HP-85 Pm gramming Example--To demonstrate a short time

error, enter the following statements into the computer:

REMOTE 707

OUTPUT707;~rQ100F2T2X”

TRIGGER707

When END LINE is pressed the thiid time, the instrument

wiU start storing readings in the buffer. However, since the

instroment cannot make resistance measurements (FZ) at

the selected interval (QlOO), short period errors will occur.

Conflict Error

A conflict error occurs when trying to store readings at a

high speed interval (lms to 14ms) while the instrument is

in an invalid state. After sending a command string that~

contains the interval command(Q), the following message

is displayed briefly when a conflid error occurs:

CONFLICI

The entire command string will be ignored and the data

store will not start.

Mid instrument states for high speed data storage are listed

in Table 3-U

3-9

A conflict error also occurs when trying to send a calibra-

tion command over the bus while the instrument is in an

invalid state, such as the dB function. The entire command

string is ignored when a conflict error occurs.

HP-85 Programming Example-Enter the following

statements into the computer to demons&ate a CONFLXT

error:

REMOTE 707

OIJTPUT 707; r L QlWX s

When END LINE is pressed the second time, a conflict er-

ror will occur because data cannot be stored at the high

speed interval of lms (Ql) with the instrument in the ohms

function (F2). The entire command string will be ignored.

3.7.2 IEEE-488 Status indicators and LOCAL

Key

The TLK, RMT, and LSN indicators show the present

IEEE-488 status of the instrument. Each of these indicators

is briefly described below.

STATUS INDICATORS

T‘K RHT LSN

El 0 Cl

LOCAL

TALK-The TLK indicator will be on when the instrument

is in the talker active state. The unit is placed in thii state

by addressing it to talk with the correct MTA (My Talk Ad-

dress) command. TLK will be off when the unit is in the

talker idle state. The instrument is placed in the talker idle

state by sending it-an UNT (Untalk) ~command, address-

ing it to~listen, or with the IFC (Interface Clear) command.

REMOTE-The RMT indicator shows when the instrument

is in the remote mode. Note that RMT does not necessarily

indicate the state of the REN line, as the instrument must

be addressed to listen with REN true before the RMT in-

dicator will turn on. When the instrument is in remote, all

front panel keys except for the LOCAL key will be locked

out. When RMT is turned off, the instrument is in the local

mode.

LISTEN-The LSN indicator will be on when the Model 196

is in the listener active state, which is activated by address-

ing the instrument to listen with the correct MLA (My

Listen Address) command. LSN will be off when the unit

is in the listener idle state. The unit can be placed in the

listener idle state by sending UNL (*ten), addressing

it to talk, or by sending JFC (Interface Clear) over the bus.

LOCAJJYhe LOCAL key cancels the remote mode and

restores local operation of the instrument;

Since all front panel keys except LOCAL are locked outs

when the instrument is in remote, thii key provides a con-

venient method of restoring front panel operation. Press-

ing LOCAL will also hum off the RMT indicator and return

the display to the~normal mode if user messages were

previously displayed with the D command.

Note that the LOCAL key will also be inoperative if the LLO

(Local Lockout) command is in effect.

HP-85

Statement Affect on Model 196

REMOTE 7

ABORT10 7

LOCALLOCKOUT

LOCAL 707

CLEAR 7

CLEAR 707

TRIGGER707

Goes into remote when next addressed.

Goes into talker and listener idle states.

Front panel controls locked out.

Cancel remote.

Returns to default conditions.’

Returns to default conditions.

Trigsem reading in T2 and T3 modes.

3-10

3.8 GENERAL BUS COMMAND

PROGRAMMING

General bus commands are those commands such as DCL

that have the same general purpose regardless of the in-

strument. Cbmmands supported by the Model 196 are

summarized in Table 3-6, which lists HP-85 statements

necessary to send each command. Note that commands

requiring a primary address assume that~ the Model 196

primary address is set to 7 (its factory default~addr&s).

3.8.1 REN (Rem’ote Enable)

REN is a uniline command that must be asserted by the

controller to place the Model 196 in the remote mode.

Simply setting REN true will not actually place the in&u-

ment in remote; instead, the units must be addressed to

listen after REN is set true.

Generdly, remote enable should be asserted before attemp-

ting to program the instrument over the bus. Once the in-

strument is in r&note, all front panel controls except

LOCAL will be inoperative. Normal front panel operation

can be restored by pressing the LOCAL key.

To place the Model 196 in the remote mode, the controller

must perform the following sequence:

1. Set the REN line true.

2. Address the Model 196 to listen.

HP-35 Programming Example-Place the Model 196 in

remote with the following statement:

REMOTE 787

When the END LINE key is pressed, the Model 196 should

be in the remote mode as indicated by the RMT annun-

ciator light. If not, check to see that proper bus connec-

tions are made, and that the instrument is programmed

for the correct primary address (7).

Note that all front panel controls except~LOCAL (and, of

course, POWER) are inoperative while the instrument is

in remote. You can restore normal front panel operation by

pressing the LOCAL button.

3.8.2 IFC (Interface Clear)

The IFC command is sent by the controller to place the

Model 196 in the talker and listener idle states; The unit

wilI respond to the IFC comman d by cancelling front panel

TALK or LISTEN lights, if the instrument was previously

placed in one of those modes.

To send the IFC co nunand, the controller need only set the

EC line true for a minimum of 100pec.

HP-85 Pmgrammi ng Example-Before demonstrating the

LFC command, place the instrument in the talker active state

with the following statements:

REMOTE 707

ENTER 707; A$

At this point, the RMT and TLK indicators should be on.

The lFC command can be sent by typing in the following

statement:

FlEORTIU 7

Note that the TLK indicator hnns off when the Eb!D LINE

key is presse-d.

3.8.3 LLO (Local Lockout)

The LLQ co nunand is used to lock out operation of the

LOCAL key, thereby completely locking outs front panel

operation of the instrument (recall that the remaining con-

trols are locked out when the instrument is placed in

remote).

To send the LLO comniand, the controller must perform

the following steps:

1. Set .4lN tie.

2. Place the LLQ command byte on the data bus.

To cancel local lockout and return control to the front panel,

REN must be set false by sending the LOCAL 7 command

to the instrument.

HP-85 Progr amming Example-To verify LLO operation,

enter the following statements:

REMOTE 707

LOCALLOCKOUT

3-11

After the second statement is executed, the LOCAL key will it does not set RBN false.

be locked out.

To cancel LLO, type in the following statement:

LOCAL 7

HP-85 Programming Example-Place the instrument in the

remote modes with the following statement:

REMott 707

When END LINE is pressed, control to the front panel will Verify that the instrument is in remote.

be restored.

3.8.4 GTL (Go To Local) Send GTL as follows:

LOCAL 7M7

The GTL command is used to take the instrument out of

the remote mode and restore operation of the front panel

keys. Note that the instrument goes into the local mode, and that~

operation of the front panel keys has now been restored.

TO setid GTL, the controller must perform the following

sequence: 3.8.5 DCL (Device Clear)

1. Set KIN true. The DCL co rmnand may be used to clear the Model 196

2. Address the Model 196 to listen. and return it to its default conditions. Note~that the DCL

3. Place the GTL command byte on the data lines. command is riot an addressed command, so ail instruments

equipped to implement DCL will do so simultaneously.

When the Model 196 receives a DCL c

ommand, it-will

TheGTLco nunand wi!.l not cancel LLO (local lockout) since r&urn to either the factory default conditions listed in Tables

2-l and 3-7 or to the user saved default conditions.

Table 3-7. Factory Default Conditions

Mode 1 Command

Multiplex

Reading

Function

Data Format

Selflrest

EOI

SRQ

Internal Digital Filter

Filter

Data Store Interval

Data Store Size

R=w

Rate

Kil

status

Enabled

A/D converter

DC volts

Send prefix with reading

Clear

Enable EOI and bus hold-off on X

Disabled

Enabled

Disabled

One-shot~into buffer

One reading

3ocN

6%d, line cycle integration

Continuous on external trigger

No delay

CR LF

l&a&d

3-12

IEEE-488 PROGRAMMING

To send the DCL command, the controller must perform

the following steps:

1. Set ATN true.

2. Place the DCL conuixmd byte on the data bus.

Notes:

1. DCL will return the instrument to the default line fre-

quency setting.

2. DCL will not have any affect on the -nt IEEE address:

HP-85 Programming Example-Place the unit in an operat-

ing mode that is not a default xondition. Now enter the

following statement into the I-Jl’-85 keyboard:

CLEAR 7

When the END LJN!? key is pressed, the inslnnnent w

to the default conditions.

3.8.6 SDC (Selective Device Clear)

The SDC command is an addressed command that per-

forms essentially the same function as the DCL command.

However, since each device must be individuslly address-

ed, the SDC command provides a method to clear only a

single, selected instrument instead of clearing all in-

struments simultaneous1 as is the case with DCL. When

the Model 196 receives t

e SDC command, it will return

to either the factory default conditions listed in Tables 3-7

and 2-1 or to the user saved default conditions.

To transmit the SDC command, the controller must per-

form the following steps:

1. Set ATN true.

2. Address the Model 196 to listen.

3. Place the SDC command byte-on the data bus.

Notes:

1. SDC will return the instrument to the default line fre-

quency setting.

2. SDC will not have any affect on the current IEEE address.

HP-85 Programming Example-Using several front~panel

controls, alter instrument states from the default wnfigura-

tion. Send SDC with ~the following statement:

CLEQR 707

When the above statement is executed, the instrument

retums to the default configuration.

3.8.7 GET (Group Execute Trigger)

GET may be used to initiate a Model 196 measurement se-

quence if the instrument is placed in the appropriate trig-

ger mode (see paragraph 3.9). Once triggered, the i&u-

ment~~will perform the measurement sequence in accord-

ance with previously selected rate and sample parameters.

To send GET, the controller must perform the following

sequence:

1. set !irN low.

2. Address the Model 196 to listen.

3. Place the GET command byte on the data bus.

HP-85 Programming Example--Type in the following

statements to place the instrument in the correct trigger

mode for purposes of this demonstration:

REMOTE~707

OCITFILIT 707; L * T3X’ ’

Now trigger the measurement sequence by sending GET

with the following statement:

TRIGGER707

When the END LINE key is pressed, the measurement se-

quence will be triggered.

3.8.8 Serial Polling (SPE,SPD)

The serial polling sequence is used to obtain the Model 196

serial poll byte. The serial poll byte contains important in-

formation about internal functions, as desoibed in

paragraph 3.9.13. The serial polling sequence can also be

used by the controller to determine which instxument on

the bus has asserted SRQ (Service Request).

F~,rial polling sequence is generally conducted as

1. The controller sets KiW true.

2. The controller then places the Sl’E (Serial Poll Enable)

command byte on the data bus. At this paint;~~all active

devices are in the serial poll enabled mode and waiting

to be addressed.

3-13

IEEE-488 PROGRAMMING

3. The Model 196 is then addressed to talk.

4. The controller sets Al-N false.

5. The instrument places its serial poll byte on the data bus

to be read by the controller.

6. The controller then sets ATN true and places the SPD

(Serial Poll Disable) command byte on the data bus to

end the serial polling sequence.

Once instruments are in the serial poll mode, steps 3

through 5 above can be repeated by sending the correct talk

address for each instrument.

HP-85 Programming Example-The HP-85 SPOLL state-

ment automatically performs the sequence justmdescn%ed.

TO demonstrate serial polling, type in the following

statements:

AEllOTE 707

S= SPOIL (797)

DISP s

When the above statements are executed, the Model 196

is serial polled, and the decimal value of the serial poll byte

is displayed on the computer CRT.

3.9 DEVICE-DEPENDENT COMMAND

PROGRAMMING

IEEE-488 device-dependent commands are used with the

Model 196 to control various operating modes such as func-

tion, range, trigger mode and data format. Each command

is made up of a single ASCII letter followed by a number

representing an option of that command. For example, a

command to control the measuring function is programmed

by sending an ASCII “F” followed by a number represent-

ing the function option. The IEEE-488 bus actuall treats

these commands as data in that ATN is false when ;I e com-

mands are transmitted.

A number of commands may be grouped together in one

s&in .

AS cl3 A command strin is usually terminated with an

“Y character, whx 3-l tells the instrument to execute

the command string. Cornman ds sent without the execute

character will not be executed at that time, but they will

be retained within an internal command buffer for execu-

tion at the time the X character is received. If any errors

occur, the instnunent will displa a

error messages and generates an J8

R propriate front panel

If programmed todo

so.

Commands that affect instrument operation will trigger a

reading when the command is executed. These-bus com-

mands affect the Model 196 much like the front panel con-

trols. Note that commands are not necessarily executed in

the order received; instead, they will be executed in

alphabetical order. Thus to force a particular command se-

quence, you would follow each command with the execute

character(X), as in the example string, Upcnx, which will

reset the instrument to factory default conditions and then

select the ohms function.

Device-dependent comman ds can be sent either one at a

time, or in groups of sweral commands within a single

string. Some examples of valid command strings include:

FOX-Single command string.

FOKlPOROX-Multiple command string.

T6 X-Spaces &e ignored.

Typical invalid command strings include:

ElX-Invalid command, as E is ndt one of the instrument

commands.

=X-Invalid co nunand option because 15 is not an option

of the F command.

If an illegal COmIMn d @DC), illegal command option

(IDDCO), is sent, or if a command string is sent with REN

false, the string will be ignored.

Device-dependent commands that control the Model 196

are listed in lkble 3-8. These commands are covered in detail

in the following paragraphs. The associated programming

scamples show how to send the commands with the HP-%

NOTE

Programming examples assume that the Model

196 is at its factory default- value of 7.

In order to send a device-dependent-command, the con-

troller must perform the following steps:

1. Set MN true.

2. Address the Model 196 to listen.

3. set MN false.

4. Send the command string over the bus one byte at a

time.

3-14

IEEE-488 PROGRAMMING

Table 3-8. Device-Dependent Command Summery

Auto Auto Auto Auto

3wmv390mv300&4m+4 3ol n hto 300 n

3v3v3mA3mA 3M

3ov3GmY3onA3GmA 3okn

hfger Mode

so 3’hd 3’/ld 3’hd 3Md 3%d(Rl-4) 5’hd 5’hd 5’hd

5w=-Rn

Sl 4Hd 4’hd 4%d 4Md 4%d@l-R4) 5Md 5’hd 5’hd

5’/zd@S-I(7

5Vtd 5’hd 5Hd 5Hd 5’hd 5’hd 5%d 5Yzd

6Hd 5’hd 5’hd 5Md 6Hd(Rl-R6) 5Md 5Yzd 6’hd

5Md(R7j

Integration period: 3Yzd=3l&sec, 4%d=ZS9nwec,

3%d and 6%d=Liie cycle

To Cmtinuous on Talk 3.9.7

E One-shot on Talk

Continuous on GET

-I3 One-shot on GET

T4 Continuous on X

T.5 One-shot on X

T6 Continuous on External Trigger

77 One-shot on External Trigger

3-15

IEEE-488 PROGRAMM,ING

Table 3-8. Device-Dependent Command Summary (Cont.)

Mode Command

Reading Mode BO

Data Store Size

Data Store Interval

Value

Calibration

Default Conditions

Data Format

SRQ

EOI and Bus Hold-of;

Terminator

SthLS

Multiplex

Vjnn.nnnn 01

V+n.nnmqnE+

M32

Description

Readings from A/D converter Readings from A/D converter

Readings from data store Readings from data store

Continuous data store mode Continuous data store mode

Parag

3.9.8 3.9.8

3.9.9 3.9.9

Data store of no (n=l to 500)

One-shot into buffer

n=intend in milliseconds (lmsec to 999999msec)

Calibration value, zero value

3.9.9

3.9.10

Calibrate first point using value (V)

Calibrate second point using value (V)~

Restore factory default conditions and save (Ll)

Save present machine states as default conditions

Readings with prefixes.

Reading without~ prefixes.

Buffer readitlgs with prefixes and buff& locations.

Buffer readings without prefues and with buffer locations.

Buffer readings with prefixes and without buffer locations.

Buffer read&s without orefues and without buffer

3.9.10

s9.11

3.9.12

locations. “~~

Disable

Reading overflow

Data store full

1 3.9.13

Data store half full

Reading done

Ready

Error

Enable EOI and bus hold-off on X

Disable EOI, enable bus hold-off on X

Enable EOI,, disable bus hold-off on X

Disable both EOI and bus hold-off on X

CR LF

4F_CR~

3.9.14

3.9.15

Send machine status word

Send error conditions

Send translator word

Send buffer size

3.9.16

Send average reading in buffer

Send lowest reading in buffer

Send highest reading in buffer

Send current value

Send input switch status (front/rear)

Auto/Cal multiplex disabled

Auto/Cal multiplex enabled 3.9.17

3-16

IEEE-488 PROGRAMMING

Table 3-8. Device-Dependent Command Summary (Cont.)

Mode

Delay

self-test

Hit Button

Display

Exponential Filter

Command Desqiption Paragraph

wn n=delay period in milliseconds, (Omsec to 6OOOOqsec) 3.9.18

JO Te&ROM, RAM, E’PROM 3.9.19

I-h Hit front panel button munber n 3.920

Da Display up to 10 character message. a=character 3.9.21

D Cq@ display mode

E. Internal filter off 3.9.22

Internal filter on ; ,.

NOTE X character will be transmitted to the instrument. No mode

REN must be true when sending device-dep~+nt changes will OCCUI withH~$ example because no other com-

commands to the instrument, or it will ignore the man& were sent. Note that the instrument remains in the

command and display a bus error message. listener active state after the command is transmitted.

General HP-85 Pmgramming Example-Device-dependent

commands may be sent from the HP-85 with the following

statement:

OUTf’UT707;AB

A!$ in this case contains the ASCII characters representing

the command string.

3.9.1 Execute (X)

The execute command is implemented by sending an ASCn

“X” over the bus. Its purpose is to direct the Model 196 to

execute other device-dependent commands such as F (func-

tion) or R (range). Usually, the execute character is the last

byte in the comrn+nd.string (a r+mber of commands may

k FTC! together mto one strmg); bowever, there may

amumstmces where it is desrable to send a com-

mand string at one time, and then send the execute

character later on. Command strings sent without the ex-

ecute character will be stored within an internal command

buffer for later execution. When the X character is finally

transmitted, the stored comman ds will be executed, assmn-

ing that alI commands in the previous string were valid.

HP-85 Pmgramming E%%nple-Enter the following state-

ments into the HZ-85 keyboard:

REMOTE 707

UUTPUT~707;“X”

When the END LINE key is pressed the second time, the

3.9.2 Function (F)

The function command allows the user to select the type

of measurement made by the Model 196. When the instru-

ment responds to a function command, it will be ready to

take a reading once the front-end is set u

P The function

may be programmed by sending one o the following

commsrlds:

FO = DC Volts

Fl = AC Volts

FZ=Ohms

F3 = DC Current

F4 = AC Client

F5 = ACV dB

F6 = AC4 dB

F7 = Offset Compensated Ohms

Upon power up, or after the instrument receives a DCL or

SDC command, the Model 196 will return to the default

condition.

HP-85 Programming Example-Place the instrument in the

ohms function by pressing the OHMS button and enter the

following statements into the HP-85 keybq%d:

REMOTE 707

OUTPUT707i”F0X”

When END LINZ is pressed the second time, the instru-

ment changes to DC volts.

3-17

\EEE-488 PROGRAMMING

3.9.3 Range (R)

The range command gives the user control over the sen-

sitivity of the instrument. This command, and its options,

erform essentialI the same functions as the front anel

kge buttons. &nge commands parameters an$ the

respective ranges for each measurings functjon are~sum_

marized in Table 3-9. The instrument wiil be ready to take

a reading after the range is set up when responding to a

range command.

Upon power up, or after the instrument receives a DCL or

SDC co mmand, the Model 196 will return to the default

condition.

HP-35 Programming Example-Make sure the instrument

is in the autorange mode and then enter the following

,statements into the HP-85:

REMOTE 707

OUTPUT 707; ’ ‘R3X’ 9

ZO = Zero disabled.

Zl = Zero enabled.

22 F Zero enabled using a zero value (V).

Sending Zl has the same effect as pressing the ZERO but-

ton. Zero will enable, and the display will zero with the

mput signal becoming the zero baseline level. The baseline

wih be stored in Program ZERO.

The 22 command is used when a zero value, using the V

command, has already been established. When the 22 com-

mand is sent, subsequent readings represent the difference

between the input signal and the value of V. Also, the value

of V is stored in Program ZERO. For example, with 0.5V

on the in ut,

result WI Ii sending the command strings V2XZ2X will

zero being enabled and the instrument reading

-1.5v (0.5 -2.0 = -1.5).

Sending the 22 comman d without a V value established

is the same as sending the Zl command. See paragraph

3.9.10 for more information on using the V command.

When the END LINE key is pressed the second time, the

instrument cancels the autorange mode, and enters the R3 Upon power up or after the instrument receives a DCL or

range instead. SDC command, the Model 196 %ill return to the default

condition. The value of V will reset to zero.

3.9.4 Zero (if) HP-85 Programming Example-Set the instruments to the

Over the bus, the zero modifier can be controlled in the 3V DC range. With the front panel ZERO button disable

same way that it is controlled from the front panel. Refer e zero mode, if enabled, and enter the following

stat ements into the HP-85 kevbosrd:

to paragraphs 2.6.2 and 2.7.15 Qro

description of the zero modifier. TE rogram) for a complete

e zero modifier is con-

trolled by sending one of the folkowing zero comman dsover REMOTE 707

. . . OUTPUT707;‘1111Xy’

the bUS: OUTPUT 707; ’ ‘ZZX’ 3

Table 3-9. Range Command Summary

I Range Offset Compensated

Command DCV ACV DCA ACA Ohms ACV dB ACA dB Ohms

Ro Auto Auto Auto Auto Auto Auto Auto Auto

Rl 3oomv 3oOnN 300 /LA 300 @A 300 0 Auto Auto 300 0

E 3i :: 3: :: 322 3;s 30 3kil m Auto Auto Auto Auto 30 3kS kD

R4 300 v 300 v 3oomA 3oomA 300 kbl AU&J Auto 30 kQ

3-18

IEEE-488 PROGRAMMING

After the END LINE key is pressed the third time, the

ZERO indicator will turn on with a zero baseline level of

1V DC. The zero value will also be stored in Pmgram ZERO.

3.9.5 Filter (P)

The filter command controls the amount of filtering applied

to the input signal. The Model 196 filters the signal by

taking the weighted average of a number of suicessive

reading samples. Since noise is mostly random in nature,

it can be largely cancelled out with this method.~The

number of readings averaged (filter value) can be from 1

to 99. The filter value can be programmed by sending one

of the following commands:

PO = Filter disabled.

Pn = Filter on with a value of n. Where n can be from 1

to 99.

Upon power up or after the instrument receives a DCL or

SDC command, the Model I96 will return to the default

condition.

Notes:

1. A filter value sent over the bus is stored in Program

FIUER, replacing the previous filter value.

2. Keep in mind that each function can have its own

unique filter value.

Ew85Rogr amming BxamphGWnh the front panel FKFER

indicator off, enter the following statements into the HF-85:

REMOTE 707

OlJTPUT707;“PZOX”

When the END LINE key is pressed the second-&ne,,the

falter will turn on and have a filter value of 20.

3.9.6 Rate (S)

The rate command controls the integration period and the

usable resolution of the Model 196. lhble 3-10 lists the usable

resolution on each function for the four S modes. The in-

tegration period is dependent-on usable resolution as

follows:

3Yzd resolution = 3l8psec

4Md resolution = 259msec

5Yzd resolution = Line cycle*

6Yzd resolution = Lime cycle*

“20msec for 5OH2, l6.6msec for 6OHz.

Upon power up or after the instrument receives a DCL or

SDC command, the Model 196 will return to the default

condition.

HP-85 Programming Example-From the front panel, Seth

the display of the Model 1% for DCV at 6Yzd resolution.

Now enter the following statements into the HP-85

REMOTE 707

OUTPUT707;“S1X3’

When END LINE is pressed the second time, the Sl rate

will be selected.

Table 3-10. Rate Command Summary

Command

DCV

3Yzd

4Yzd

5Yzd

6%d

Integt

ACV

3%d

4Yzd

5%d

5%d [

Id:

m peril

DC4

3Yzd

4Yzd

5Yzd

ACA

3Yzd

4Yzd

5Yzd

5r/zd

LCV dB

5Yzd AC4 dB

5%d

5Yzd 5Yzd 5Yzd

5Yzd 5Yzd 6Yzd

,.v. .

bd=259msec, 5Y’a ana bYza=Lme cycle.

,~~

3.19

IEEE-488 PROGRAMMING

3.9.7 Trigger Mode (T)

Triggering provides a stimulus to begin a reading conver-

sion within the instrument. Triggering may be done in two

basic ways: in a continuous mode, a single trigger com-

mand is used to start a continuous series of readings; in

a one-shot trigger mode, a separate trigger stimulus is re-

quired to start each conversion. The Model 196 @eight

trigger commands as follows:

TO = Continuous on Talk

Tl~ = One-shot on Talk

T2 ~= Continuous on GET

I3 = One-shot on GET

T4 = Continuous on X

T5 = One-shot on X

T6 = Continuous on External Trigger

T7 = One-shot on External Trigger ~ ~~~~~

The trigger modes are paired according to the type of

stimulus that is used to trigger the instrument. In the ‘IO

and~Tl niddes, t+iggering is performed by addressing the

Model 196 to talk. In the T2 arid T3 modes, the IEEE-488

multiline GET command performs the trigger function. The

instrument execute (X) character provides the triggeT

stimulus in the T4 and T5 modes. External trigger pulses

provide the trigger $imuhrs in the T6 ,and T7 modes.

Upon power up or after the instmment receives a DCL or

SDC cbmmtid, the Model 196 will return to the default

condition.

NOTE

With the instrument in the T6 and T7 trigger

modes, the front panel ENTER button can be us-

ed to trigger readings. See paragraph 2.8 fqor details.

HP-85 Pmgmmming Exampl+Place the instrument in the

one-shot on talk mode with the following statements:

REMOTE 707

OLlTPUT707j~“Tl:x:”

One reading can now be triggered and the resulting da@

obtained with the following statements:

ENTER 787; A4:

DISP A$

In this example, the ENTER statement addresses the Model

196 to talk, ate which point a single reading is triggered.

When the reading has been processed, it is sent out over

to the bus to the computer, which then displays the result.

3.9.8 Reading Mode (B)

The reading mode command parameters allow the selec-

tion of the source of data that is transmitted over the

IEEE-488 bus. Through this comman d, the user has a choice

of data from the A/Dmv%ter (normal DMM readings)

or the buffer (data store).~The reading mode commands are

as follows:

BO = A/D converter readings

Bl = Data Store readings

Upon power up or after the instrument receives a DCL or

SDC command, the Model 196 wiIl return to the default

condition.

When in BO, normal A/D reading+ will be sent~. In a con-

tinuous trigger mode, readings will be updated ate the con-

version rate. The Bl command is used to access readings

from the buffer. When the Bl command is sent, subsequent

readings will be taken from consecutive buffer locations

beginning with the first memory location (001). Once all

readings have been requested, the unit will cycle back and

begin again.

HP-85 Programming Example-Enter the following

statements into the computer to send a reading over the

bus and display it on the computer CRT.

REMOTE 707

OUTPUT 707~; ’ ’ EnXI ’

ENTER 707 i A$

DISP A9

The second statement above sets the instrument to the AID

converter reading mode. The third and fourth statements

acquire the reading and display it~~on the CRT.

3.9.9 Data Store Interval (Q) and Size (I)

The data store is controlled by the interval command (Q).

and the size command (I).

3-20

IEEE-488 PROGRAMMING

J.nterval

With the Q comman d, the user can select the interval that

the instrument will store readings or select the one-shot

mode. In one-shot, one reading will be stored each time

the instrument is triggered. The Q cmnman d is in the

following form:

QO=Oneshot into buffer.

Qn=Set storage interval in millisec (lmsec to 999999tiec).

To use the data store in the one-shot mode (QO), the in-

strument must be in a one-shot trigger mode (cc n, T5

or T7). In the QOTl mode, one reading will be stored each

lime the instrument is addressed to talk. In the QClI3 mode,

each GET co mmand will cause one reading &q be store&

ln the QOT5 mode, each instrument execute character (X)

will cause a reading to be stored. Fmally, in the Qm mode,

each external trigger pulse will cause a r&ling to be stored.

If the instrument is in a continuous trigger mode (To, T2,

T4 or T6), any IDDC error will occur.

NOTE

With the instrument in the T7 trigger mode, the

front uanel ENTER button can be used to manuallv

store’readings into the buffer. Each press of thk

ENTER button wilI store one reading in t&e buffer.

See paragraph 2.8 for details.

To store readings at a selected interval (Qn), the instrument

must be in a continuous trigger mode f,lU, T2, X, T6). &en

the selected trigger occurs, the storage process will

commence.

NOTE

With the instrument in the T6 trigger mode, the

front panel ENTER button can be used to start a

series of readings to be stored in the buffer. The

storage interval and buffer size are determined by

the Qn and I co mmands respectively. See

paragraph 2.8 fork details.

siie

The size of the data store can be controlled by one of the

following I commands.

IO=Continuous storage mode.

In=Set data store size to n (1 to 500).

In the continuous data storage mode (IO), storage will not

stop after the buffer is filled (500 readings), but will pro-

ceed back to~the first memory location and start oven&kg

data. V+h the Innn command, the storage process will stop

when the defined number of readings have been stored.

In this case the buffer is cdnsidered to be fuli.’

Notes:

1. When the Q or I co

mmand is sent, ‘c---i’ will be

displayed until the first trigger occurs.

2. The data store can be disabled by sendine: the F com-

mand. Storage will again resume’when &appropriate

trigger occurs.

The instrument must be in a valid operating state (see

%ble 3-11) in order to use the high speed data store

capabilities. The high speed intervals are lmsec through

lknsec. The instrument display will blank while the in-

strument is storing readings at high speed. If the ins&u-

ment~ is not in a valid operating state for high speed

storage, a conflict error will be displayed briefly and

storage will not occur.

The short time error message indicates that the in&u-

mentcannot store readings at the programmed interval

rate. Instead, readings will be stored as fast as the in-

strument can run.

With S2 or 53 asserted, the fastest valid storage interval

(I) is 3lmsec and 35msec respectively. A shorter inter-

val will result in a short time error when the storage pm-

c&s is started. Readings will be stored as fast as the in-

strument can run.

Either during or after the storage process, readings may

be recalled by using the Bl command as described in

the previous paragraph. Also, the highest, lowest and

average reading in a full buffer can be recalled by send-

ing the ,appropriate U commands. See paragraph 3.9.16

for information on using the U commands.~

Upon power up or after the instrument receives a DCL of

SDC command, the Model 196 will return to the defaults

condition.

~Hp-85 Programming Example-Enter the program below

to enable data store operation and obtain and display 100

readings on the computer CRT:

3-21

PROGRAM COMMENT3 _.__.. _-_-. .~

10DItlA8C25l

20 REMOTE 70.7 Send remote enable.

30 OUTPUT 707; Set trigger mode, and

‘1T2~3001100X” storage parameters.

40TRIGGER707 Start storage process.

50 OUTPUT 707: Set read mode to data

s ‘BiGBX” StOK?.

60FORI=lTO100 Set counter for 100

loops.

70ENTER707iR8 Get a reading.

00 DISPA$ Display reading.

30 NEXT I toop back for next

reading.

100 END

After entering the program, press the HP-85 RUN key. The

program will set the store size to IOO (line 30), enable the

data store (line 4O), turn on the data store output (line 50),

and then request and display all 100 readings (lines 6O-l.OO).

3.9.10 Value (V) and Calibration (C)

Otie ;Idvanced feature of the Model 196 is its digital c&bra-

tion capabilities. Instead of the more difficult method of

adjusting a number of potentiometers, the user need only

apply an appropriate calibration signal and send the caliira-

tion value over the bus.

The V command is also used to program a zero value (see

paragraph 3.9.4).

Fhy command may take on either of the following

VM.mlNm

Vn.nnnnnnE+n

Thus, the following two comman ds would be equivalent:

V3.OE+l

,.$ @is example, note that only as many significant digits

as necessary need be sent. In this case, the exact value is

assumed to be 3OMxxx) even though only the first two digits

were adually sent.

Digital Calibration-When performing digital c&ration,

two points must be caliiated on each range. The first

caliiation value should be approtiately full range and

the second calibration value should be approximately zero.

After the second calibration value is sent over the bus, per-

manent storage of the two values will occur.

In order to send calibration values over the btxs, the caliia-

tion command (C) must be sent after the value command

(V) is sent. The calibration command takes on the follow-

mg form:

cO=Calibrate first point using value (V)

Cl=Calibrate second point using value Iv)

The following example first sends a caliiration value of 3

and then a calibration of 0.

WXCOX

VOXCIX

If the calibration value is greater than 3030000 counts (at

61Ad resolution) an lDDC0 error message will be displayed

on the Model 196.

CAUTION

Precision calibration signals must be connected

to the instrument before attempting calibration,

otherwise instrument accuracy will be affected.

See Section 6 for complete details on calibrating

the instrument either from the front panel or over

the bus.

Table 3-11. High Speed Data store

. . .~.

Data Store Valid Reading Valid Valid Valid Date

Interval Rate FundiOnS Ranges* Store Site*

QL Q2 so FO, FYL F3, F4 Rl-R7 Il-I500

Q3-Q14 so, Sl FO, F-l, F3, M Rl-R7 Il-I500

*Data store size IO (continuous) and Ro (autorange) cannot be used in

the high speed data store mode.

3-22

IEEE-488 PROGRAMMING

3.9.11 Default Conditions (L) Thus, the current IEEE address and line frequency set-

ting are saved by IJ.

The LO cotiand allows the user to return the instrument 2. Sending Ill is equivalent to running Program 37 (Reset)

to the factory default conditions. Factory default conditions and then Program 30 (Save), thus:

are set at the factory and are listed in Tables 3-7 and 2-l.

The imtmment wiIl power up to these default conditions. A. User saved defaults will be lost since fact&y default

conditions will be saved.

The current IEEE address and line frequency setting of the

instrument are not affected by the M command. B. M will not change the current IEEE address and line

frequency setting, and will save them as the default

conditions.

The Ll command is used to save the current instrument

conditiO116. The ir!StrUment wiu then power up t0 these

default conditions. ~&&j fiogmmming E-@-&t the Model 196 to the

ohms function, and enable zero and filter. Now, enter the

following statements into the computer:

Any of the options of the following device-dependent com- REMOTE 787

mar& can be saved as the default conditions: CIUTPIJT~~~;“L~X”

A (multiplex), F (function), N (internal filter), P (digital

filter), Q ad 1 (data Store h-ttemd and Sue), R (ra%d, s After pressing END LINE the second time, cycle power on

(rate), W (delay), and Z (zero). the Model 196 and note that the hmment retins to the

conditions initially set in this example.

The L command options are as follows: 3.9.12 Data Format (G)

L&Restore instrument to factory default conditions and

save (Ll). The G comman d controls the format of the data that the

Ll=Save present machine states as the default conditions. instrument sends over the bus. Readings may be sent with

or without prefixes. Prefixes are the mnemonics preceding

the reading and the buffer memory location. Figure 3-6 fur-

Notes: ther clarifies the general data format. The G comniands are

as follows:

1. Sending Ll is equivalent to running program SAVE.

+NONE’NO READINGS IN

DATA STORE

pREFIx~~A~~“~A ‘: D’G”s~~~~~R,,~O~~~~~~N

NDCV +I.234567 E + 1 .ESOO CR LF

DCV=OC VOLTS

ACV=AC VOLTS

1 L7”;;;;g!yR

EXPONENT

OHH=OHMS

OCO=OFFSET COMPENSATED OHNS

DCI=DC AMPS

ACI=AC ANPS

dBV=AC dB VOLTS

dBI=AC dB AMPS

Figure 3-6. General Data Format

3-23

IEEE-408 PROGRAMMlNG

GO = Send single reading with prefixes. Examples:

NDCV-1.234567E+D (A/D reading)

NDCV-1234567E+O,BOOl (buffer reading)

Gl = Send single reading without pwfixes. Etim$es:

-1234567E+O (A/D reading)

-1234567E+0,001 (buffer reading)

G2 = Send alI buffer readings, separated by co-s, with

prefixes and buffer memory locations. Examples:

NDCV-l.Z34567E+O,BOOl,NDCV-1.765432E+

O,BOO2, etc.. .

G3 = Send aII buffer readings, separated by commas,

without prefixes and with buffer memory locations.

Example: -1.2X!WE+O,IX?~-1.765432E+O,M?2, etc...

G4 = Send alI buffer readings, separated by commas, with

reading prefixes and without~ memory buff&r loca-

tions. Example:

NDCV-1.234567E+O,NDCV-1.765432E+O,etc...

G5 = Send all buffer readings, separated by co-s,

without reading prefixes and without buffer memory

locations. Example:

-1234567E+O,-1.765+0, etc...

Upon power up or after the instrument receives a DCL or

SDC ~command, the Model 196 will return to the default

CO*diti0*.

Notes:

HP-85 Progr

amming Example-To place the instrument in

the Gl mode and @@n a reading, enter the following

statements into the m-85 keyboard:

REMOTE787

When the second statement is exerted, the instrument wilI

than

data fr

e to the Gl mode. The last two statements acquire

om the instiment and display the reading string

on the CRT. Note that no prefii or suffix appears on the

da@ string.

3.9.13 SRQ Mask (M) and Serial Poll Byte

Format

The SRQ command controls which of a number of condi-

tions within the Model 196 wiU cause the instrument to re-

quest service from the controller by asserting an SRQ. Once

an SRQ is generated, that serial p* byte can be checked to

determine if the Model 1% was the instrument that asserted

the SRQ and if so, what conditions can be checked by using

the Ul command, as described in paragraph 3.9.33.

1. The B command affects the source of the data. In the

BO mode, the bus data wiIl come from the A/D converter. The Model 196 can be programmed to generate an SRQ

In the Bl mode, the data wiIl come from the buff& under one or more of the following cqncjitions:

2. The Bl command must be asserted when using the G2 1. When a reading is completed or an overrange condition

through G5 modes. oaxrs.

3. Pro~ammed terminator and EOI sequences appear at 2. If a bus error occurs.

the&d of each reading in the GO and Gl mddes, but 3.~ When the data store is full.

are transmitted only at the end of the buffer in the G2

through G5 modes. No terminator is sent if in G2 4, men the data store is yz full.

through G5 modes while in BO (data from A/D). ~‘~ ~~~

5. If a trigger overrun error occurs.

6;~When the bus is ready.

BIT

POSITION

VALUE

DECIMAL

WEIGHTING

I=SRQ BY 196 (STATUS BYTE ONLY) I=READING OVERFLOW

I=ERRDR I= BUFFER FULL

I-READY l=BUFFER HALF FULL

I’READING DONE

Figure 3-7. SRQ Mask and Serial Poll Byte Format

3-24

IEEE-488 PROGRAMMING

Upon power up or after a DCL or SDC co~%id is re-

ceived, SRQ is disabled.

SRQ Mask--The Model 196 uses an internal mask to deter-

mine which conditions will cause an SRQ to be generated.

Figure 3-7 shows the general format of this mask.

SRQ can be programmed by sending the ASCII letter “M”

followed by a decimal number tom set the appropriate bit

in the SRQ mask. Decimal values for the various bits are

summarized in Table 3-12. Note that the instrument may

be programmed for more than one set of conditions

simultaneously. To do so, simply add up the decimal bit

values for the required SRQ conditions. For example, to

enable SRQ under reading overflow and buffer full condi-

tions, send M3X. To disable SRQ, send MOX. This command

wi!.l clear all bits in the SRQ mask.

Table 3-12. SRQ Command Parameters

Command ( Cond#qn to Generate SRQ

MO Disable

Ml Reading overflow

iii Data store full

Data store half full

ibE3 Reading done

Ready

M32 Error .-~~

Serial Poll Byte Format-The serial poll byte contains in-

formation relating to data and error conditions with@ the

instrument. The general format of the serial poll byte

(which is obtained by using the serial polling sequence, as

described in paragraph 3.88) is shown k Figure 3-7.

The bits in the serial poll byte have the following meanings:

Bit 0 (Reading Overtlow)-Set when an overrange input is

applied to the inshument.

Bit 1 (Buffer Full)-Set when the defied buffer size is full.

Bit 2 (Buffer Yz Full)-Set when half the defined buffer size

isfoll.

Bit~3 (l%adirg Done)-Set when the instrument has com-

pleted the present reading conversion.

Bit 4 (Ready)-Set when the instrument has processed all

previously received commands and is ready to accept ad-

ditional commands over the bus.

Bit 5 (Error)-Set when one of the following errors have

occurred:

1. Trigger Error

2. Short Tie

3. Big String

4. UncaGxated

5. Cal Locked

6. Conflict

7. No Remote

8. IDDC

9. IDDCO .~~

10. Translator _

The nature of the error can be determined with the Ul com-

mand asexplained in paragmph 3.9.16. An explanation of

each error can also be found in paragraph 3.9.X

Bit 6 [SRQ)-Provides a means to determine if an SRQ Was

asserted by the Model 196. Jf this bit is set, service was re-

quested by the instrument.

Bit-7-Not used and always set to zero.

Note that the status byte should be read to clear the SRQ

line once the instroment~has generated an SRQ. All bits

in the status kyte will be latched when the SRQ is

generated. Bit 6 (RQS) will be cleared when the status byte

is read.

I-IF-85 Programming Example-Enter the following pro-

gram into the m-85:

PROGRAM COMMENTS

10 REMUTE 797 @ CLEAR 7 Set up for remote

operation, clear

instrument;~~~

20 UIJTPUT 707; r r M32X’ y Promm for SRQ on

Ipwo.

30 OIJTPLIT 7M7; 8 ‘KSX’ ’ Attempt to program

40 S=SFOLL<707:) ille@bptioti. -

Serml poll the

insbxment.

~~IF~OTEIT(SIS)THEN~~ WaitforSRQemor.

50 DISF “B7 B6 B5 E4 B3 BZ Identify the bits.

El RQ”

60 FOR I=7 TOM STEF~-1

~BDISFEIT<SII).:

80 NEXT I

90 I!ISF

l&3 END

Loop eight times.

Displav each bit

po&i&.

3-25

Once the program is entered and checked for errors, press

the HP-85 RUN key. The computer first places the instru-

ment in remote (line lo) and then programs the SRQ mode

of the instrument (line 20). Line 30 then attempts to pro-

gram an illegal command option, at which point the in-

strument generates an SRQ and sets the bus error bit in

its status byte. The computer then serial polls the instru-

ment (line 4O), and then displays the status byte bits in pro-

per order on the CRT. In this example, the SRQ (B6) and

error (85) bits are set because of the attempt to program

an illegal command option (K5). Other bits may also be set

depending on instrument status.

3.9.14 EOI and Bus Hold-off Modes (K)

mode is that no bus commands will be missed whilethe

instrument is processing commands previously received.

The hold off period depends on the commands beingpro-

cessed. Table 343 lists hold off times for a number of dif-

ferent commands. Since a NRFD hold off is employed, the

handshake sequence for the X character is complete.

NOiE

With KD or Kl asserted, hold-off will also occur on

an EOI and a terminator. These delays allow for

proper operation of the Translator software, since

“X” cannot be used in Translator words.

The K command allows control over whether or not the in-

strument~sends the EOI command at the end of its data HP-85 Programming Example-To program the instrument

&in and whether or not bus activity is held off (through for the K2

the&FDline)untilallcommandssenttotheinstrUment Hp-85’

mode, enter the followmg statemats into the

are inteniay processed once~the instrument receives the

X chamter. K command options include:

KO = Send EOI with last byte; hold off bus until com-

FiEMOTE 707

‘OUTPUT 797 i r r KZX ’

mands processed on X.

Kl = Do not send EOI with last byte; hold off bus until When the second statement is executed, the instrument will

7 commands processed on X. be placed in the K2 mode. In this mode, EOI will still be

K2 = Send EOI with last byte; do not hold off bus on X. transmitted at the end of the data string, but the bus hold-

off mode w$l be disabled.

K3 = Send no EOI with last byte; do not hold off bus on X.

Upon power up, or after the instrument receives a DCL or

SDC co

mmand, the instrument will return to the default

condition.

The EOI line on the IEEE-488 bus provides a method to

positively identify the last byte in a multi-byte transfer se-

quence. Keep in mind that some controllers 1~4y on EOI

to terminate their input sequences. In this case, suppress-

ing EOI with the K command may cause the contr@er in-

put sequence to hang unless other terminator sequences

are used.

The bus hold off mode allows the instrument to temporarily

hold up bus operation when it receives the X character until

it processes all co mmands sent in the command string. The

purpose of the hold off is to ensure that the front end FETs

and relays are properly configured before taking a reading.

Keep in mind that all bus o

tivity associated with the hf eration will cease--not just ac-

ode1 196. The advantage of this

Table 3-13. Bus Hold-off Times (Typical)

Commands

Function (F]

Range CR)

Calibrate (C

Others

Bus Held-off on X for:

1OOmsec on DCV (FO), Ohms (F2) and

Compensated Ohms (F7)

63Omsec on ACV (Fl), ACA (F4), DBV

(F5) and DBA (F6)

16Omsec on DC4 (F3)

lOOmsec on most range conunands

l7Omsec on 3OM0 (F2R6) and 34OMQ

(Fuv) ranges

638msec per range comman donACV

(F’4 and Aa 0

9sec on most functions

IBSsec on 3OM0 (E?R6) and 3WMll

0 ranges

94msec to llOmsec depending on com-

mand sent

lsec for selftest (JO) command

3-26

IEEE-488 PROGRAMMING

3.9.15 Terminator (Y)

The terminator sequence that~marks the end of the instm-

merit’s data string or status word can be programmed by

sending the Y command followed by an appropriate

character. The default terminator sequence is the commonly

used carriage return, line feed (CR LF) sequence (YO). The

terminator will assume this default value upon power up,

or after the inshxment receives a DCL or SDC command.

Programmable terminators include:

YO=CRLF

Yl=LFCR

M=CR

Y3 = LF

Y4 = No terminator

HP-85 Progr amming Example--To reserve the default (CR

LF) terminator sequence, type the following lines into the

computer.

REMOTE 707

OLITFUT 767j r i YBX ’

When the second statement is executed, the normal ter-

minator sequence will be reserved; the instrument will ter-

minate each data string or status word~with a (CR LF).

3.9.16 Status (U)

The status command allows access to information con&m-

ing various operating modes and conditions of the Model

196. Status commands include:

LJO = Send machine status word.

Ul = Send error conditions.

UZ = List Translator words.

U3 = Send a value indicating the buffer size.

U4 = Send the average reading in the data stores.

U5 = Send the lowest reading in the data store.

U6 = Send the highest readiig in the data store.

U7 = Send the present value (V).

U8 = Send input switch status (front/rear).

When the command sequence UOX is transmitted, the in-

strument will transmit the status word instead of its nor-

mal data string the next time it is addressed to talk. The

status word will be transmitted only once each time the

UO command is given. To make sure that correct status i+

transmitted, the status word should be requested as soon

as possible after the con-man d is transmitted.

The format of UO status is shown in Figure 3-8. Note that

the letters correspond to modes programmed by the respec-

tive device-dependent comman de.. The default values in the

status word are also shown in Figure 3-8. Note that all

returned values accept for those associated with the ter-

minator correspond to the programmed numeric values.

For example, if the instrument is presently in the R3 range,

the second (R) byte in the status word wiJ.l correspond to

an ASCII 3.

The Ul command allows access to Model ‘I.96 error condi-

tions in a similar manner. Once the sequence UlX is sent,

the instrument will transmit the error conditions with the

format shown in Figure 3-9 the next time it is addressed

to talk in the normal manner. The error condition word will

be sent only once each time the Ul command is transmit-

ted. Note that the error condition word is a&ally a string

of ASCII characters representing binary bit positions. An

error condition is also flagged in the serial poll byte, and

the instrument can be programmed to generate an SRQ

when an enur condition OCCUIS. See paragraph 3.9.13. Note

that all bits in the error condition word and the serial poll

b e error bit~will be cleared when the word is read. In ad-

d? hon, SRQ~ op%r&ion will be restored after an error con-

ditionby reading Ul.

The various bits in the error condition word are des-

aibed as follows:

TRIG ERROR-Set when the instrument receives a trigger

while it is still processing a reading from a previous trigger.

SHORT TIME-Set when the instrument cannot run as fast

as the selected data store interval.

BIG STRING-Set if more than a 10 character message is

sent using the display (D) command.

UNCAL-Set when EVROM memory fails the self test. In-

strument calibration is invalid.

CAL LQCKED-Set when t@ng to &irate the instrmnent

with the calibration switch in the disable position.

CONFLICT-Set when trying to calibrate the instrument

while it is in an improper state. (i.e. dB function).

Translator Error (TRANSERR)-Set when any one of ten

possible Translator enors occur. Table 3-15 in pmagraph 3.10

lists and describes the Translator errors.

NO REMOTE-Set when a progamming command is

received when REN is false.

IDDC-Set when an illegal device-dependent command

(IDDC), such as ElX is received (“El’ is illegal).

3-27

IEEE-408 PROG!%tblMlNG

,, :

FACTORY DEFAULT

1 0 0 0 0 0 00 1 00 000000 4 3 6 00000 0 0 011

CAL

196 A B F 0 J K MM N PP QQQQQQ R S T WWWWW Y Z SW

MODEL NUMBER PREFIX (196) RANGE (R,

A”To,oAL MWTIPLEX (A, OffSet

O=OIS*sl.ED Dcv *cv DCA COmpenSated

AU OHMS

l=ENAsLEo ACVdS ~.KAdS O)I,?s

Re*DING MODE (B,

O=AJD CONVERTER

l=DATA STORE SUFFER

FUNCTION (0

o=oc “OUS

,=*c VOLTS

2=OHMS

3=x CURRENT

&-AC CURRENT

SELFTEST (.I)

O=INACTI”E

l=ROM. RAM and E’PROM PASSED

2=E*PROM FAILED

EXPONENTIAL FILTER (i-4) Z=ENPISLED USING ZERO VALUE

O=OISASLED

,=EN*BLED cALIBRATlON SWITOH

“=“lSARI F”

Figure 3-8. 00 Machine Status Word and Default Values

~_____ .,, ~,.,”

3-28

IEEE-488 PROGRAMMING

IDDCO--Set when an illegal device-dependent command

option (IDDCO) such as T9X is received (“9” is illegal).

NOTE

The corn lete command string will be ignored if

an IDD P , JDDCO or no remote error occurs.

The U2 command lists the Translator words that have been

defined by the. operator. The list will be transmittedonly

once each time fhe command is received.

The U3 command allows the user to find out the current

defined size of the buffer. The buffer Size iFZ&olled by

the I command. When this command is transmitted, fhe

instrument will transmit the value the next time~it is ad-

dressed to talk. This information will be transnxi&d only

once each time the command is received. The U3 value will

not be cleared when read; thus, the U3. value is always

current.

The U4 command sends the average of all the readings that

are in the data store. The U5 conun~nd sends the lowest

reading in the data store and the U6 command sends the

highest. When any of these co mmands are transmit@$fhe

instrument will send the appropriate reading the next time

the instrurnent~is addressed to talk. A reading will only be

sent-once each time the appropriate command is received.

~gyni&on of U4, U5 and U6 will not occur until the buf-

The U7 command sends the present value. The value can

be a calibration value, or a zero value.

The US command sends a value that defines~ the status of

the input switch. A value of 0 indicates that the~front pariel

input terminals are selected, while a value of ~1 indicates

that the rear panel input terminals are selected.

HP-85 Progamming Example-Enter the following

statements into the computer to obtain and display the

machine status word (UO).

PROGRAM COMMENTS

10 REMOTE 707

xi DIM ABC401 Send remote enable.

30 UIUTPUT 7U7 ( L UBY’ y

, I Send UO command.

40 DISP * ~mdlHBFGJKtltlN

PPQ~!aaP~RSTWWWl,lWY

Z%‘” ~~~~~~~~~~ ~~~

50 EHTER~TWT; At: obtin uo stibls from

instrument.

60 UISF-‘-A5 Display UO status word.

7U ENTER 707; RB ~Get n&mal reading.

:m III% A$ Display normal reading.

30 END

After eni+ng the program, run it by pressing the HP85

RUN key. The machine conditions of the Model 196 will

be listed on the CRT display. To show that status is &ansn&

ted only once, a normal reading is requested and displayed

last.

3.9.17 Auto/Cal Multiplex (A)

The Model 196 has built-in multiplex routines that

automatically calibrate and zero the instrument, so as to

maintajn its high accura

defeated, either through x The multiplex routines can be

ant panel Program 6 (paragraph

2.25) or through one of the following comma$.s:

A0 = Disable multiplex

Al = Enable multiplex

Upon power up or after a DCL or SDC command, the in-

strument will return to the default-condition.

HP-85 Programming Example-Disable multiplex by enter-

ing the following statements into the I-E-85:

REMOTE 707

OUTFUT 707; “AOXx 5

When the END LINE key is pressed the second time, the

multiplexer routines will be disabled.

3-29

l=lRIG ERROR

rl=SHORT TIME

196 d/l k/l O/I O/i 0 0 0 O/l O/I O/I

I=CAL LOCKED’

I=CDNFLICT

I-TRANSERR 9

O/I O/I D/l

I-ND REMOTEA

I--IDDC

‘i

l=IrJOCO

0 D/l O/I

I=lRANSERR23

ALUAYS ZERO, 1

O/I O/I O/I O/I O/I D/l ;, Oil

I=TRANSERRPI

I=TRAMSERR20

I-TRANSERRIS

1 LI=TRANSERR17

l:TRANSERR16

LI=TRANSERRIk ~

l=TRANSERRl4

AlhAYS ZERO

IEEE-488 PROGRAMMING

3.9.18 Delay (IV)

The delay command controls the time interval that occurs

horn the point the inslrument is triggered until it begins

integration of the input signal. This feature is useful in

situations where a specific time period must transpire to

allcw an input signal to settle before measurement. Dur-

ing the delay period, the inputs multiplexing FETs ar@

switched on so the inshument is set to begin integration

upon conclusion of the programmed delay period. A delay

period can be programmed using the following command:

Here, n represents the delay value in milliseconds. The

range of programmable delay values is from Omsec to

600Oflmsec.

Examples: For a delay of 0.002sec send W2X.

For a delay of 30.05sec send W3005OX.

For a delay of 60sec send W6OOOOX.

Upon power up or after receivin a DCL or SDC commtidj

the instrument will return to t

a e default condition.

HP-85 Pmgr amming Example--To program a 25Omsec delay

period into the instrument, enter the following statements

into the computer:

REMOTE 707

OUTPUT 707; I’WZ5OX”

After the END LINE key is pressed the second time, the

instrument will wait for 25Omsec after each triggered con-

version before executing the next coversion period.

3.9.19 Self-Test (J)

The J command causes the instrument to perform tests it

automaticsJly performs upon power up. When the self-test

command is given, the Model 196 perfor?ns the following

tests:

1. ROM Test

2.RAMTest

3. EIPROM Test

J command parameters include:

JO = Perform self-test.

Ifthe self-test is successful, the J byte in the UO status word

will be set to 1. If E’PROM fails, the message ‘VNCAL!’

will be displayed and the J b te in the Ul status word will

be set to 2. Ati EzPROM f a3 ore is also flagged~in thg Ul

status word. If ROM and RAM fails, the instrument will

lock up.

recomme&tions to resolve a failure.

See paragra h 6.7.2 for more information on these tests and

HP-85 Programming Example-Enter the following

statements into the computer to perform the Model 196

self-test:

REMOTE 707

OUTPUT 707.: ’ s JOX” ’

When the END LINE key is pressed the second time, the

instrument erforms the self-test. If sUCcessful, the self-test

byte (J) in tK e UO~status word will be set to 1.

3.9.20 Hit Button (H)

The hit button command allows the user to emulate vir-

tually any front panel control sequence. Through the use

of-the H command, the front panel programs may be

entered through commands given over the bus. The H com-

mand is sent by sending the ASCII letter followed by a

number representing a front panel control. These control

numbers are shown in Figure 340.

E@ples:

H3x-Selects the ACA function.

HOX-Selects the ACV function.

HP-85 Programming Example-Enter the following

statements into the computer to place the instrument in the

ohms function:

REMOTE 707

OUTPUT707j”HiX”

When the END LINEkey is pressed the second time, the

instrument is placed in the ohms function.

3-31

Figure 3-10. Hit Button Command Numbers

3.9.21 Display (D) Notes:

1. In order to have spaces preceding the beginning oft the

The display command controls the ASCII messages that message and between message words, use the @ sym-

can be placed onto the Model 196 display. Messages are bol to represent~each space. For example, to-display the

controlled with the following commands: message “Model 196” starting at--the seconds display

character (one space), send the following command

Da = DIsolav character “sT’, where “a” reoresents a orint~ble string:

A&II’ character. tip to 10 chkacters (&&ding

blanks) may be sent. c d D@tlODEL@i=c5V’ 5

, .a

D =~ Restores display back to normal. 2. Spaces in a command string are ignored.

3. Sending a message that exceeds 10 characters will results

with the big string error message being @splayed.

3-32

IEEE-488 PROGRAMMING

HP-85 Programmi ng Example-Enter the following state- HP-65 Programming Example-Enter the following

ments into the computer to display the message “MODEL statements into the computer to turn the internal filter off:

196”: HEMITE 707

REMOTE 707 UUTPIUT 797; 6 G HMX 5

WTFUT 7073 r r DWlOIIELCi96 X3 ’ : -

When the END LINE key is pressed the second time, the

When the END LINE key is pressed the sec+d time the internal filter will disabled.

instrument model number will be displayed: Display opera-

tion may be returned to normal by entering the following

statement: 3.10 TRANSLATOR SOFTWARE

OUTPUT 767; 6 6 I!:+~ ’ The built in Translator software allows the user to define

his own words in place of Keithley’s defined device-

3.9.22 internal Filter (N) dependent commands. One word can replace a single com-

mand or a string of commands. For example, the,word ACV

can be sent in place of Fl, and the word SETUP1 can be

In addition to the digital filter (P), a running average filter sent in place of F3R1T2S~ZllJOMZFl5. Also, Keithley corn-

is used to provide additional filtering when making high mands can be translated to emulate functions of other units.

resolution and high sensitivity measurements. The inter- For exam$e, the~word RA, which is used by H-P to select

ml filter is controlled by the following commands: ~autorange, can be sent in place of RO. There are Yertain

words and characters that cannot be used as defined

NO = Internal filter off. Translator words. These reserved words and character make

Nl = Internal filter on. ;!4;he Translator software syntax and are listed in Table

The factory default condition of the internal filter is Nl

(enabled).

Table 3-14. Translator Reserved Words and Character

Word/Character Description

ALIAS

SAVE

LET

FORGET

Used at~the beginning of a command string to define Translator words.

Used to terminate the Translator string (one space must precede it).

Used to define wild card Translator words. Values sent with a wild card

Translator word select options of the equivalent DDC.

Tells the Model 196 to recognize Translator words.

Tells the Model 196 to only recognize the Keithley device-dependent

commands.

Saves~Translator Words as power up default.

Used to list the Translator words.

Used to purge Translator words from memory.

3-33

3.10.1 Translator Format Notes:

1. Trying to define a Translator word that already exists will

The basic format for defining a Translator word is shown cause an error message to be displayed briefly. Thatk

in the following example command St&g, whi&d&ines Translator word will retain its original definition.

the word SEZIJR as a substitute for FlROX. 2. A.Translatoi word cannoi exceed 31 characters.

‘ALIAS sETuPl FlROX ;” 3. The Translator buffer can hold approximately 100

B-character Translator words.

4. The character X and $ cannot be used in Translator

Where: words.

ALIAS is a reserved word that precedes the Translator 5. The Model 196 will not recognize an undefined Translator

word. word sent over the bus.

SETUPl is the desired Translator word. 6. A valid Translator word sent over the bus while the in-

FlROX is the Keithley command string. strument is in the OLD mode will not be recognized.

However, the instrument will try to execute (on the next

; is a reserved character necessary to tetiate the

Tran%lahx stig. X) the letters and numbers of the word as if they were

device-dependent commaqds.~ To avoid this problem, it

(spaces) must be used to separate words and the “;” is recommended that NEW be sent before trying to ex-

character. ecu@Translator words. See paragraph 3.10.3 for an ex-

planation oft NEW and OLD.

When SETUFl is sent over the IEEE-488 bus, the in&u-

ment will go to the ACV function (Fl) and enable autorange 7. Translator error messages are listed and described in

Table 3-7.5.

Translator words that contain conflicting device-dependents HP-85 Programming Example-Enter the following pro-

command.?., such as Fl and F2, can be defined. When send- &ati into the c&i@uter &define a Translator word

ing the comma d word over the bus, the device-dependent (SETUPI) to emulate-the command string FIROX:

command that was last entered will prevail. For example, REMOTE 7M7

sending a Translator word in place of FOFYX will place the C~UTPLlT767r’LALIASSETlJPiFlROXi’~

instrument in the Fl function. UUTFUT707; ‘rSETUP1’!

Table 3-15. Translator Error Messages

Display

Message Explanation Example Error String

TRANSERR 9 No more memory left for Translator words. -

TRANSERR14 Use of more than one ALIAS in a definition. “ALIAS TESTI l?lX ALIAS TEST2 RLX ;‘I

TRANSERRl5 Translator word exceeds 31 characters. ‘RUAS ITwNKTHIs1sTHIRpITw OCHARACT

ERS! FIX ;I’

TRANSERRl6 Use of an X in a Translator word. “ALIAS XRAY FIX ;”

TRANSFERl7 Trying to define a Translator word ~&at alre@y “ALIAS SETUl? FIX ;”

exists. The second string in the example is the “ALJAS SETUP RlX ;”

error shing.

TRANSERRB Use of a $ in a Translator word. ‘ALIAS $200 FCC;”

TRANSERRl9 Sending the ; character. n.,,

TRANSERR20 Use of LIST in a Translator definition. kIAS DOG FlX LIST ;”

TRANSERR21 Use of FORGET in a Translator_definition. “ALIAS DOG FJX FORGET ;”

TRANSEKQ.3 Use of SAVE in a Translator definition. ‘NJAS DOG FIX SAVE ;”

3-34

IEEE-488 PROGAAMMlNG

When END LlNE is pressed the second time, the Translator

word will be defined to emulate the Keithley command

string. When END LlNE is pressed the third time, the in-

strument will go to the ACV function (n) and enable

autorange (RO).

3.10.2 Wild Card ($)

An advanced feature of Translator software is its wild card

capabilities. By using the reserved character~“$‘: the same

basic Translator word can beg used to select all options of

a command. With this feature, a DDC~ option number is

sent with the wild card Translator word. The format for

using the wild card is shown in the following wple,

which defines the word FUNCTION as a substitute for the

F command:

“ALIAS FUNCTION F$X ;”

“FLlNCl-ION ~1”

“FUNCTION 2’

The first statement defines FUNCTION as the wild card

Translator word for the F command. The wild card ($) will

allow any w&d option number of the F command (0

through 8) to be sent with the word. The second statemtint

which is the substifute for the Fl command, will place the

instrument in the ACV function. The third statement is a

substitute for the F2 command, and will place the instru-

ment in the ohms function.

Notes:

1. When sending a wild card Translator word over the bus,

there must be a space between the Translator word and

the option number.

2. If a wild card Translator word is sent without an option

number, the instrument will default to option 0.

HP-85 Pmgramming Example-Enter the following pro-

gram to define a wild card Translator word to emulate the

P (filter) command.

REMOTE 707

OUTPUT7Bij rrALIASFILTERP$Xj”

OUTPUT707; 11FILTER20”

The second statement defines FIUER as the wild card

Translator word for the P comman d. The third statement

enables the filter with a filter value of 20.

3.10.3 NEW and OLD

NEW is a reserved word that tells the instrument that the

ensuing commands may be defined Translator words. The

instrument will then respond to the Transistor words as

well as Keithley device-dependent comman ds. The re-

served word ALIAS automatically places the instrument

in the NEW mode. NEW is also used to combine Translator

words and is explained in paragraph 3.10.4.

OLD is a reserved word that preventsthe instrument from

tisponding to the defined Translator words. In this mode,

only the Keithley device-dependent commands will be

recognized cwer the bus.

HP-85 Programming Example-Enter the following state-

ments into the computer to place the instrument in the

NEW mode:

~- REMOTE 707

OUTPUT 7137; s ‘HEW ’

When ENlILINEis pressed the second time, the instru-

ment~wiu go into the NEW mode.

3.10.4 Combining Translator Words

Existing Translator words can be combined resulting in a

Translator word that contains the cow ds of the two (or

more) combined words. For example, exist&~ Translator

words SETUP and SETU2 can be combined and

named SETUPB When SETUP3 is sent over the bus, the

commands of both SETUP1 and SETUP2 will be executed.

The f-t fir combining Translator words is shown in the

following e+nple:

“ALIAS SETUP3 NEW SETUP1 NEW SETUP2 ;”

Where:

SETUP3 is the new Translator word.

SETUPl and SETUP2 are words to be combined.

NEW is a reserved word that tells the instrument that

SETUFl and SETUP2 are Translator words and not Keithky

device-dependent commands.

Even though the two words were combined to form

SETUP3, SETUPI and SETUI’2 still exist as valid Translator

words.

3-35

IEEi-488 PROGRAMMING

Wild card Translator words can also be combbied with other

Translator words. The option number used with the new

word will apply only to the fir& wild card word in the

string. For example, assume that FILTER (emulating the P

command) and FUNCTION (emulating the F command)

are wild card Translator words that are to be combined with

the normal Translator word SETUPl. The format might look

like this:

“ALIAS TEST NEW SETUPl NEW FUNCTION

NEWFIU’ER;”

The new Translator word is TEST. Whenever TEST is sent,

the option value sent with that word will only affect futic-

tion since FUNCTION is the first wild card command in

the string. For example, TEST might be sent~oyq the bus

in the following format:

‘TEST 3”

The “3” in the command string will ony affect the FUNC:

TION command. In this example the instrument will be

placed in the DCA function (F3). Since the FILTER com-

mand does not have an assigned option value (due to its

position in the s’xing), it will default to 0 (disable).

HP-85 Progr

amming Example--The following program will

create two Translator words and then combine them to form

a third Translator word:

REllnTE 707

OUTPUT707i”ALIASSETUPlFlX I)’

_._ _-

The second and third propam statementsdefine the two

TraiBlator words. When END LINE is pressed a fourth

time, the two words combine to form the new word

(SETur3).

3.10.5 Combining Translator Words With

Keithley IEEE-488 Commands

One or more existing Translator words (iicluding wild card

words) can be combined with Keithley IEEE commands

resulting in a Translator word that contain! the commands

of the Translator words and the Keithley IEEE comqqds.

The format for cotibirdng Translator words with~I+ithley

IEEE commands is shown in the following example:

“ALIAS SETUP3 NEW SETUPI NFW SETUi=Y~PlZlX i”

Where:

SETUP3 is the new Translator word.

SETUl?l and SETUP2 are the existing words.

PlZlX is the Keithley IEEE command string.

NEW tells the instrument that SETUPl and SETUP2 are

Translator words.

When the Translator word SETUP3 is asserted over the bus,

the commands of the two Translator words and the Keithley

IEEE command string will be executed.

HP-85 FYogr amming Example-The following program will

tieate’two TIanslator words and then combine them with

a Keithley IEEE cornman< string to form a new Translator

woid:

REMOTE 707

OlJTPUT~707i”ALIkSSETUPl FiX i”

OUTPU~707i1’ALIASSETUP~R0Xi”

OUTPlJT707;“ALIASSETUP3t4EWSETUPi

N3l SETUP2 PlZlX i”

The second and third statements create two Translator

words. When END LINE is pressed the fourth time, the

two Translator words are combined to form the word

slguP3:

3.10.8 Executing Translator Words and Keithley

IEEE Commands

Translator words (includmg wild card words) and Keithley

IEEE commands can be executed in the same command

string. The fortit for doing this is demonstrated in the

following examples:

“SETUR Mzy(”

TlJNCIlON 2 PEW

When the first command string is sent over the bus, the

commands in SETUPl and the Keithley IEEE commands

will be executed. When the second string is sent, the se-

cond option of the wild card FUNCTION command and

the Keithley IEEE commands will be executed.

Hp-85 Programming Example--The following program will’

as+ the commands of an existing Translator word and

the,$+dard Keifhley IEEE commands over the bus:

;

REMOTE 707

3-36

When END LINE is pressed the second time, the corn- The second and third statements will send the word list

man& of SETUP1 and the Keithky IEEE comman ds to the computer. When END LINE is pressed a fourth time,

(FElX) will be sent over the bus. the Translator words will be displayed.

3.10.7 SAVE 3.10.9 FORGET

Translator words can be remembered by the instrument as FORGET is a reserved word that is used to purge all Trans-

power up default words by sending the reserved word

SAVE. If SAK is not Sent, Translator words will be lost lator words from temporary memory. However, Trarislator

when the instrument is turned off; Program 37 (Reset) is words that were saved in ElPROM by the SAVE command

will again Je ~qailable after power to the instrument is

run, or an SDC, DCL or M is sent over the bti. cycled, Program 37 (Reset) is RUN, or DCL, SDC or Ul is

sent over the bus.

When SAVE is sent, the instrument also remembers if it

was in NEW or OLD. Jf the instrument is in NEW when

SAVE is sent, it ~wiu power up in NEW. If the instrument

is in OLD when SAVE is sent, it will power up in OLD.

HP-85 Pmgr

amming Example--with one or more Translator

words already defined, enter the following statements in-

to the computer to retain them as power up default words:

REMOTE 787

OUTPUT707;*LSA’JE”

When END LINE is pressed the second time, current

Translator words will become power up default words.

3.10.8 LIST

LIST is a reserved word that can be used to lit the existing

Translator words stored in temporary memory. The most

recent defined word will be listed first.

To u e Translator words from EY’ROM, first send the

FO iis G T comnd and then send the SAVE command.

HP-85 Programming Example-Enter the following

statements into the computer to purge all Translator words

from temporary memory:

REMOTE 707

OUTPIJT 707; * r FORGET’ p

When ENDLINE is pressed the second time, the Translator

words are purged from temporq memory.

3.11 BUS DATA TRANSMISSION TIMES

A primary consideration isthe length of time it takes to

obtain a reading once the instrument is triggered to make

a conversion. The length of time will vary somewhat de-

pending on the selected function and higer mode. Table

3-16 give-s typical times.

Notes:

1. The UZ command can also be used to list the Translator Table a-16. Trigger To Reading-Ready Times

(DCV Function)

words (see paragraph 3.9.16).

2. If there are no Translator words in memory, nothing will

be displayed when the list is requested.

HP-85 Programming Example--With Trtilator words

already defined, enter he following program statements to

list them:

REMUTE7CI7 ~~~

OlJTPUTiEVi‘~LIST’~

ENTE~R 707; A5

DISP A$

Configuratioa

SOAOGlNOTIX

SL4OGlNOTlX

S2AOGlNOTlX

S3AlGlNOTlX

S3AlGlNlTlX

Mode

Maximum Reading

Rate (3%d)

4Md

5Yzd

6Yzd

(internal filter off)

6%d

(internal filter on)

Tie (typical)

6msec

Smec

24msec

106msec

3.3sec

“Commands not listed are at factory default.

3-3713-38

SECTION 4

PERFORMANCE VERIFICATION

4.1 INTRODUCTION 4.3 INITIAL CONDITIONS

The procedures outlined in this section may be used to

verify that the instrument is operating wifhin the limits

stated in the specifications at the front of this manual. Per-

formance verification may be performed when the instru-

ment is first received to ensure that no damage or misad-

justment has occurred during shipment. Verification may

also be performed whenever there is a question of instru-

ment accuracy, or following calibration, if desired.

The Model 196 must be turned on and allowed to warm

up for at least two hours before beginning the verfication

procedures. If the instrument has been subject to extremes

of temperature (outside the range specified in paragraph

4.2), additional time should be allowed for internal

temperatmes~ to reach normal operating temperature.

Typically, it takes one additional hour to stabilize a unit that

is 10°C (18°F) outside the specified temperature range.

NOTE

If the instrument is still under warranty (less than

1 year from the date of shioment). and its oerfonn-

, I.

ante falls outside the specified range, contact your

Keithley representative or the factory to determine

the correct course of action.

4.2 ENVIRONMENTAL CONDITIONS

All measurements should be made at 18 - 28’C (65~ 182°F)

and at less than 80% relative humidity.

4.4 RECOMMENDED TEST EQUIPMENT

Table 4-l lists all test equipment required for verification.

Alternate equipment may be used as long as the substitute

equipment has specifications at least as good as those listed

in the table.

NOTE

The verification limits in this section do not include

test equipment tolerance.

Table 4-l. Recommended Test Equipment

Description I Specifications

DC Voltage Calibrator

AC Voltage Calibrator

AC Power Amplifier

300mV, 3V, 3OV, 3OOV ranges *15ppm.

3OOmV, 3V, 30V ranges; 2OHz H.l%;

50Hz-20kHz 9.02%; 1OOkHz M.33%.

3OOV range: 2OHz B3.12%; 5OHz-2OkHr M.04%;

lookHz~.1%

3COQ-3MQ ranges il5ppm; 30MQ i32ppm;

300MR ranee~B25nnm

Resistance Calibrator

AC-DC Current Calibrator 300~~3A n&es +..d3’% DC, +o.l% AC to 5kHz (at

full scale output)

4-I

PERFORMANCE VERIFICATION

4.5 VERIFICATION PROCEDURES

The following paragraphs contain procedures for verifying

the one year accuracy specifications of the instniment,~ at

5%d resolutiofi, for each of the five mea&@ fticiions:

DC volts, TRMS AC volts, ohms, TRMS AC amps,~ and DC

amps. These procedures are intended for use only by quali-

fied personnel using accurate and reliable test equipment.

If the instrument is out of specifications and not under war-

ranty, refer to Section 6 for calibration procedur+

WARNING

The maximum common-mode voltage (voltage

between inout low and chassis aroundt is 5OOV.

Exceeding this value may cause-a breakdown in

insulatlon, creating a shock hazard. Some of the

procedures in this-section may expose the user

to dangerous voltages. Use standard safety

precautions when such dangerous voltages are

encountered.

see that~ the reading for each range is within the limits

listed in the table.

7. Repeat the procedure for each of the mnges with negative

voltages.

Table 4-2. Limits for DC Volta Verification

196 Applied Allowable Readings

DCV Range DC Voltage (wto 28T)

1 I I

300mV 3OO.OOOmV 299.974 to 300.026

3 v 3.00000 TV 2.99987 to 3.00013

30 v 30.0000 v 29.9973 to 30.0027

300 v 300.000 v 299.970 to 300.030

4.5.1 DC Volts Verification

With the Model 196 set tom5Yzd resolution, verify the DC

volts function as follows: Figure 4-1. Connections for DC Volts Verification

CAUTION

Do not exceed 300V between the input HI and

LO terminals or damage to the instrument may

occur.

4.5.2 TRMS AC Volts Verification

With the instrument set to 5%d resolution, perform the

following procedure to verify the AC volts function:

1. Select the DCV function and autorange.

2. Cdiinect the DC voltage calibrator to the Model ‘I96 as

shown in Figure 41.

3. Set the calibrator to OV and enable zero on the Model

19fYVerify that the display is reading OOO.OOOmV ~2~

counts.

NOTE

Low measurement techniques should be used

when checking the 3oOmV DC range. Refer to

paragraph 2.6.5 for low level measurement

considerations.

4. Set the calibrator to output +3OOmV and verify that the

reading is within the limits listed in Table 4-Z.

5. Disable zero and leave it disabIed for the remainder of

the DCV verification procedure.

6. Check the 3V, 3W, and 3OOV ranges by applying the

respective DC voltage levels listed in Table 42. VeqJo

CAUTION

Do not exceed 3OOV RMS 425V peak lOV*Hr

between the input HI and LO terminals or instru-

ment damage may occur.

1. Select the ACV function and &orange. Do not use zero

to cancel the offset in this procedure. Turn zero off, if

it is enabled.

2. Connect the AC calibrator to the Model 196 as shown in

Figure 4-2.

3. Set the calibrator to output 29OmV at a frequency of 2OHz

and verify that the reading is within the liits listed in

Table 4-3.

4. Repeat the 290mV measurement at the other frequencies

specified in Table 43.

5. Repeat the~piocedure for the 3V, 30V and 300V ranges

by applying the respective AC voltages listed in Table 4X%.

Check to see that the reading for each range is within

the limits listed in the table.

4-2

PERFORMANCE VERIFICATION

Table 4-3. Limits for TRMS AC Volts Verification

I96

ACV Rang

300mV

3 v

30 v

300 v

Applied

AC Voltagg

29O.OOOmV

2.9OOOOV

29.oooov

29O.ooOV

I Allowat

2OH~zP 5oHz

284.100 289.030

29soo to-

290.970

2.84100 2.89030

to to

2.95900~ 2.90970

28.4100

28.9030

to-

29;5900 29&o

284.100 289.030

to to

295.900 290.970

289.465 289.465 288.640 283.900

Z&35 29&35 291.360 29&Xl

12.89465 1 2.89465 1 2.88930 I 2.85350 I

2.9:35 2.9%35 2.9%0 2.9+&O

28.9465 28.9465 28.8640 28.5350

I to I to I tom I to I

29.0535 29.0535 29.1360 29.4650

*Do not apply 290V at 1OOkHz to the input. This exceeds the V-Hz limit~of the instrument.

Maximum TRMS AC volt input at XlOkHz is 1OOV On the 300V range, allowable readings

witYq 1OOV @ 1OOkHz applied to~~the input are 98.200 to 101.800. See paragraph 2.6.7 for

clarification of the V*Hz specification.

HI POWER ‘AC VOLTAGE

INPUT AMPLIFIER 1 CALIBRATOR

LO MODEL 5215A,MODEL 5200A

Figure 4-2. Connections for TRMS AC Volts

Verification

4.5.3 Ohms Verification

With the Model 196 set to 5%d resolution, verify the ohms

function as follows:

..CAUT!ON

Do not exceed 425V peak or 3OOV RMS between

the input HI and LO terminals or damage to the

instrument may occur.

1. Select the ohms function and autorange. ~~~

2. Using Kelvin test leads (such as the Keithley Model 1611)

connect the resistance calibrator to the Model 196 as

shown in Figure 43.

3. Set the caliirator to the SHORT position and enable zero

on the Model 196. Verify that the display reads 000.000.

4. Set-the calibrator to output 19OQ and verify that the

~--reading is within the limits listed instable 44.

5. Disable zero and leave it disabled for the remainder of

the ohms verification procedure.

6. Utilizing Figures 43 and 44, check the 3kQ through

XlOMa ranges by applying the respective resistance levels

listed in Table 4-4. Verify that the readings~are within the

limits listed ins the table.

4-3

PERFORMANCE VERIFICATION

Table 4-4. Limits for Ohms Verification

196 Ran e

300 n

3kQ

30 kfl

300 kQ

3Ml-J

3OMQ

3OOMQ

set up

Figure 4-3

Figure 43

Figure 4-4

Figure 44

Figure 4-4

Applied

Resistance

190.000 61

1.90000 kQ

19.0000 k61

190.000 kdl

1.9OoOOMQ

19.OOOOMfl

lOO.OOOMQ

OUTPUT HI

=SENSE HI RESIST~ANCE

CALIBRATOR

tiODEL 196 SENSE LO tiODEL StSOA

OUTPUT LO’

Figure 4-3. Connections for Ohms Verification

(300n--3OkQ Range)

OUTPUT HI

MODEL 196 CABLE

RESISTANCE

CALIBRATOR

MODEL 5450A

OUTPUT LO

Figure 4-4. Connections for Ohms Verification

(300kQ-300MO Ranges)

Plowable Readings

(WC to 28T)

189979 to 190.021

1.89985 to I.90015

18.9985~ to 19.OGl5

X39.958 to 190.042

1.89958 to 1.90042

18.9808~ to 19.0192

97.998 to 102.002

~4.5.4 DC Current Verification

With the instrument set to 5%d resolution, verify the DC

current function as follows:

CAUTION

Do not exceed 3A to the AMPS and LO input ter-

minals or the rear panel current fuse will blow.

1. Select the DC4 function and autorange.

2. Conned~the DC current calibration source to the Model

196 as shown in Figure 45.

3. Set the calibration source to output +3OOfi and verify

that the reading is within the liits listed in Table 45.

4. Repeat the procedure for the 3mA,3OmA, 3OOmA and

3A ranges by applying the respective DC current levels

listed in Table 45. Check to see that the reading for each

range is within the limits listed in the table.

5. Repeat the procedure for each of the ranges with

negative current levels.

Table 4-5. Limits for DC Current Verification

l96 Range

300 PA

3m.4

3om.4

3oomA

Applied

DC Current

300.000 pA

3.ooooonL4

3o.ocKlonL4

300.000!&4

3.OOOOO A

299.710 to 300.290

2.99840 to 3.00160

29.9840 to 30.0160

299.84Oto 300.160

2.99720 to 3.00280

4-4

L CURRENT Lo Lo DC VOLTAGE

CALIBRATOR INPUT CALIBRATOR

MODEL 2500E ,,, T MODEL 5440A

PERFORMANCE VERIFICATION

2. Connect the AC current calibratiori source to the Model

196 as shown in Figure 4-6.

3. Set the calibration source to output 3006 at a frequen-

cy of 20Hz and verify that the reading is within the limits

listed in Table 4-6.

4. Repeat the 3OOd measurement at the other frequencies

specified in Table 4-6.

5. Repeat the procedure for the 3mA, 3Om.4, 3OOmA and

3A ranges by applying the respective AC current levels

listed in Table 4-6. Check to see that the reading for each

range is within the limits listed in the table.

Figure 4-5. Connections for DC Current Verification

4.55 TRMS AC Current Verification

With the instrument set for 5%d resolution, verify the AC

current function as follows:

CAUTION

Do not exceed 3A to the AMPS and LO input ter-

minals or the rear panel current fuse will blow.

-I

L CURRENT Lo Lo AC VOLTAGE

CALIBRATOR INPUT CALIBRATOR

MODEL XOOE HI 7 MODEL 5200A

Figure 4-6. Connections for TRMS AC Current

1. Select the ACA function and autorange. Do not use zero Verification

to cancel the offset in this procedure.

Table 4-6. Limits for AC Current Verification

4-514-6

SECTION 5

PRINCIPLES OF OPERATION

5.1 INTRODUCTION

This section contains an overall functional desaiption of

the Model 196. Detailed schematics and component loca-

tion drawings are located at the end of $s instr@on

manual.

5.2 OVERALL FUNCTIONAL DESCRIPTION

A simplified block diagram of the Model 196 is shown in

Figure 5-1. The instrument may be divided into two sec-

tions: analog and digital circuitry. The analog and digital

sections are electrically isolated from each other by the use

of pulse transformers for control and communications.

Separate~power supplies for the analog and digital secfiotis

ensure proper isolation.

The analog section consists of the signal condition&g cir-

cuits, multiplexer, input amplifier, A/D converter and con-

trol circuitry. The heart of the digital sectioq is 6FBO9

microprocessor that supervises the entire operation of the

instrument. Additional digital circuitry includes the diipl<~

and IEEE-488 interface.

5.3 ANALOG CIRCUITRY

The detailed circuitry of the Model 196 analog section is

located on schematic diagram number 196-126.

5.3.1 Input Signal Conditioning

Signal conditioning circui~~modjfie~ the input to a signal

that is usable by the Model 196 and applies that signal to

the multiplexer.

DCV

Signal conditioning fork the 30V and 300V ranges is per-

formed by resistor divider network Rl7. On these ranges,

Kl and K2 are open, and the divider network is connected

to signal ground through Qll vd U22A. The following at-

tenuation of the input signal is provided:

Divided by 10 on the 30V range.

Divided by I.00 on the 300V range.

On the 30V range, Ql3 is on and 43 is off routing the in-

put %ignaJ in the multiplexer (Q35). On the 3OOV range, 413

is off and Q3 is on routing the input signal to the multiplex-

er (Q35). On the 3OOmV and 3V ranges, the input signal

is removed from the resistor divider network (Ql.3 and Q3

off) and applies directly to the multiplexer thrdugh Kl and

RI?.

ACV

The basic steps involved in ACV conditioning are as follows:

1. Relay K4 applies the ACV input to the gain circuitry. Here

the signal undergoes a gain factor of 10 (3OOmV range),

1 (3V range), I.00 (30V range) or WIIO (300V range).

2. The signal is then applied to the TRMS converter (U27)

where the AC si& is converted to a DC signal.

3. The DC signal is then applied to the multiplexer.

On the 3OOmV and 3V ranges, the signal is routed through

relay K5 and buffer U28A. On the 3V range, the signal pro-

ceeds through analog switch LJZlC and buffer U26B before

being applied to the TRMS converter (U27). On the 3OOmV

range, the signal is detoured through analog switch UZlA

to UZSB which is configured as a Xl0 amplifier. The

amplified signal then proceeds through analog switch UZlB

and buffer U26B to the TRMS converter (U27).

J.n the 30V range, the signal is applied to U26A. Because

analog~switch U23C is open on this range, amplifier U26A

has a feedback resistance of 1lBkO (R32) which results in

a gain factor of 1110. The divided signal is then routed

through analog switch U23B and buffer IJ26B to the TRMS

converter (WY).

On the 300V range, the signal is applied to U26A. Because

analog switch U23C is closed on this range, amplifier U26A

has a feedback resistance of 118kn (l732) in parallel with

l3kn (RZ4), resulting in a gain factor qf 1/lIlO. The divided

~signal is then routed through analog switch U23B and buf-

fer U26B to the TRMS converter (U27).

5-l

PRINCIPLES OF OPERATION

I INPUT CONOITIONlNG I

DCV

ATTENUATION/

n REF RESISTORS

INPUT A/D

AMPLIFIER CONVERTER

+ /p

ANALOG

.----------~---__-- ---_----,---

DIGITAL

INTERFACE FRONT PANEL

BUTTONS

DISPLAY

Figure 5-l. Overall Block Diagram

OHMS 300kQ range: R17A I R17C (IOOkQ)

3M61 range: @7A II Rl7B (lMQ)

Resistance measurements are made using the ratiometric 30MlI and 3OOMQ ranges R37C (1OMQ)

technique (see Figure 5-Z). When the resistance function

is selected, a series circuit is formed between the ohms

source, a reference resistor and the external unknown By ~easwing the four inputs to the A/D converter the

resistance. A cant flows through the reference resistor unknown resistance can be computed by the

and the unknown resistance. Since this current is common microprocessor using this equation:

to both resistances, the value of the unknown resistance

can be calculated by measuring the voltage across ale i=‘.&(Vtl SENSE HI - VQ SENSE IQ)

reference resistor and the voltage across~the unknown Rx T

resistance. vnREFHl- VlaREFLO

The following ohms reference resistors are used (see Figure For the 3OOQ orange VQ SENSE HI and VQ SENSE LO are

5-3). a&ally multipled by a factor of 10 in the input buffer

circuit.

3OOQ and 3kQ ranges: R26 (2W)

3OkQ range: RZ3~ (3Okfl)

5-2

PRINCIPLES OF OPERATION

Protection on the ohms ranges is accomplished by RTl, Q9 Since the voltage is sensed across the combined resistance

and Ql6. For an input voltage applied to the Q input ter- of R,, Rx and Q; considerable error can be introduced into

minals, Q9 and Ql6 clamp the voltage to the reference the reading. To use a 4-terminal connection, a second set

resistors toasafelimit.RTllimitsthecumnttoQ9amdQ16. of leads (R2 and R3) are connected to the unknown

resistance. The amount of current through R2 and R3 is

much smaller than the current through Rl and R4. Thus,

The Model 196 is equipped to make Z- or 4.-terminal resis- the voltage seen by the instrument is much closer to the

tance measurements. Generally 4-terminal measurements actoal value across the measured resistance, minimizing the

should be made on the 3003 range because the relatively error.

large output current can develop a significantvoltage across

the test leads, affecting measurement accuracy. DCA and ACA

Figure 5-2 shows the equivalent circuit of the input circuit. The resistor current shunt network R28 is configured so that

Rx is the unknown measured resistance and Rl, R2, R3 and a full scale current input will result in a 3oOmV drop across

R4 represent the test lead resistance. R2 and R3 are con- the network on all current ranges. For DCA, this voltage

netted only during 4-terminal measurements. When using

a 2-terminal configuration, all the current flows through the is routed to the multiplexer through analog switch U24B.

For ACA, the signal is routed through lJ2m~o Xl0 ampliser

test leads Rl and R4. If Rx has a low value, the amountof~ U28B. The amplifier signal then travels through analog

voltage developed across the test leads can be significant. switch U2lB and buffer U26B to the TRMS ConVerter. The

converted DC signal is then routed to the multiplexer.

FRONT PANEL ; 1 in REF HI

CONNECTOR I

INPUT; RREF l

RI “,’ I I

Jv& I

I ; Vn REF LO

r----SENSE1 RS I

I0 vn

iSENSE HI

I R3 I I I

ME c i 0

L---JSENSEl vn

LO I iSENSE LO

I Rs I

R4 I I

ALL I I

INPUTI I

LO I I

RX = RREF. cvn TENSE HI - vn SENSE Ed)

vn REF HI - vn REF ~0

Figure 5-2. Input Configuration During 2 and 4-Terminal Resistance Measurement

5-3

PRINCIPLES OF OPERATION

01;

REFERENCE

RESISTORS

INPUT

n REF HI >V~U35 OF

MULTIPLEXER

R17A R17B R17C

IOMfl R26

Llllnn 110.95kn Loozkn

n REF LO

4) ( 30kn 1

>TO U24A OF

MULTIPLEXER

n REF LO

, TO U240 OF

(3oon. 3kn I >WJ‘TIPLEXER

a13 a3 u220

ai1

n REF LO TO a34 OFT

(300kn - soonn I >wJLTIPLEXER

E HI > TO a30 OF tlULTIPLEXER

\ II SENSE LO

/ >TO U22B OF RULTIPLEXER

INPUT

\ LO

/ RREF. (Vn SENSE HI - Vn SENSE LO)

RX = vn REF HI - vn REF LO

Figure 5-3. Resistance Measurement Simplified Circuitry

5.3.2 Multiplexer formed by the A/D converter, and the resultant data is

used by the microprocessor to calculate the fiial reading.

The multiplexer circuitry selectsamong the var+us signals

that xe part of the Model 196 measurement cycle and con-

nects them to the input~buffer amplifier. Figure 5-4 shows The precharge amplifier (UZOB) is momentarily selected by

a simplified schematic of the multiplexer circuitry The Q31 just before signal FET 430 is activated. The purpose

Front/Rear INPUT switch detector TJ75B is not part of a of the precharge amplifier is to get the signal seen by the

measurement cycle. mput buffer amplifier closer to the actual input~~at signal

FET Q30: The precharge ampliier also provides the drive

to keep the FE% on until turned off by the control circuitry.

Figure 5-5 shows the general switching phases for the

various signals. During each phase, an integration is per-

5-4

PRINCIPLES OF OPERATION

SIGNAL (SOOsdOC. 3VDC) Q30

II SENSE HI

PRECHARGE 031 1

SIGNAL (DCA) U24E

. lo

il REF LO (3Okn)

II SENSE LO

ZERO (3OV) U22A

Ia 033 ,

n REF Lo (3ook-3ootm)

SIGNAL ( BOVDC, 300VDC) 03s

n REF HI 012

Figure 5-4. JFET Multiplexer

5-5

PFilNClPLES OF OPERATION

REFERENCE REFERENCE

PHASE PHASE

L L

SIGNAL SIGNAL

PHASE PHASE

J/ J/

ZERO ZERO

PHASE PHASE

J/ J/

CALCULATE CALCULATE

A READING A READING

II REF HI

PHASE

XL xl/

fT REF LO fT REF LO

PHASE PHASE

.L .L

II SENSE HI II SENSE HI

PHASE PHASE

XL XL

II SENSE LO II SENSE LO

PHASE PHASE

\1 \1

CALCULATE CALCULATE

A READING A READING

A. TYPICAL YDLTAGE AND A. TYPICAL YOLTAGE AND 8. TYPICAL RESISTANCE MEASUREMENTS 8. TYPICAL RESISTANCE MEASUREMENTS

CURRENT HEASUREflENlS CURRENT HEASUREflENlS

Figure 5-5. hlutliplexer Phases

5-6

PRINCIPLES OF OPERATION

5.3.3 +2.1V Reference Source 5.4 AID CONVERTER

Voltage and current measurements are based on compar-

ing the unknown signal with an internal +&lV reference

voltage source. During each measurement cycle, the

unknown signal is sampled and then compared with signal

common and the +2.1V reference values.

U34 provides a highly stable +6.95V reference, while Ul3

and RlO provide a constant current to minimize zener

voltage variations. R36 and R37 divide down the +6.95V

value to the final +t.lV reference voltage.

5.3.4 input Buffer Amplifier

The input buf The input buffer amplifier provides isolation between the

input signal ana tne x/u converter. u41 pro\ input signal and the A/D converter. 441 provides the low The integrator is made up of Ql, Ul9 and C32. When the

noise, high impedance FET input for amplif noise, high impedance FET input for amplifier U35. The input to the integrator is applied, the integrator output

amplifier can be configured for Xl or X10 gain amplifier can be configured for Xl or X10 gain with R41 and ramps up until its voltage is slightly higher than the voltage

R42 acting as the feedback network. Whel R42 acting as the feedback network. When Xl gain is applied to the inverting input of ~the duty cycle comparator

selected by the mipprocessor, feedback is 101 selected by the mipprocessor, feedback is routed through (U5A). The charge balance current, whose duty cycle is pro-~

pin 12 of the analog switch U44A. At Xl0 ga pin 12 of the analog switch U44A. At Xl0 gain, feedback portional to the input, is fed back to the integrator input

is routed through pin I3 of~the multiplex switc is routed through pin I3 of~the multiplex switch. Amplifier through R8 and Q4. Since the charge balance current-is

gain configurations for the various function gain configurations for the various functions tid ranges much larger than the sum of the input and level shift-cur-

are listed in Table 5-l. are listed in Table 5-l. rents, the integrator output now ramps in the negative

direction until 0 of LJ8B eoes low. The VJA then counts

The Model 196 uses a tionstant~ frequency, variable pulse

width, analog-to-dig@ converter. A simplified schematic

of t~he ~A@ used in &he Model 196 is shown in Figure 5-6.

The charge balance phase begins when~ the input enable/

disable line is set high. This occurs at the end of a software-

generated delay period thatallows the signal to settle after

the appropriate multiplexer FET is turned on. Once the in-

put + Fabled, the sign+ from the buffer amplifier is added

to the level shift current applied through RllC and RllD

or RllC only. In this manner, the i3.03V bipolar signal from

the buffer amplifier is converted to a unipolar signal that

can be integrated.

the total numb& of oul& that occur during the charze

Table 5-1. Input Buffer Amplifier (U35) Gain balance phase. *

Range

3oomv

3-300V

All

3k-E&*

All

;ain

==I

At the end of the charge balance phase, the output of the

integrator is resting at some positive voltage. Since the in-

tegrator output is connected to the non-inverting~ input of

the final-slope comparator (U5B), the final-slope corn-

par&o+ output remains high until the integrator output

ramps in the negative direction. During fin@-slope, Q4 is

huned off and the feedback is fed through U16 back to the

integrator input;The fmal-slope comparator output is then

gated with the 3.84MH.z clock and counted. Once the com-

parator output goes low, the VJA stops counting and the

reading can be computed.

5-7

PRINCIPLES OF OPERATION

., ..,

3.84NHz U43D

CLOCK > IO 1102

lJ88 FINAL SLOPE

-0 COMPARATOR

-ii RllF

CURRENT U7.

us4

FEEDBACK

DUTY CYCLE CONTROL

COMPARATOR CIRCUIT

Figure 5-6. AID Converter Simplified Schematic

5.5 CONTROL CIRCUITRY 5.6 DIGITAL CIRCUITRY

The signals for the circuitry that provides control of the

” arious FETs, relays, analog switches and logic levels are

supplied by the shift store registers U.29, U30, U31, and U32

(see schematic 196-126, page 3). CLOCK, DATA and

!ZROBE signals are sent from the VIA (U109) across the

pulse transformers T103, T104 and TlO5 (see ~schematic

196-106). The pulse transformers provide 5OOV isolation be-

tween the analog and dig&J sqtions of~tlw~nstrument.

DKIYA is serially loaded into the shift store registers and a

STROBE pulse causes the registers to simultaneously~~ut-

put the appropriate logic levels to the FET, analog switch

and relay drivers.

The Model 196 is controlled by an internal microcomputer.

This section briefly desoibes the operation of the

microcomputer and associated digital circuitry. Refer to

schematic diagram number 196-106 ftir circuit details.

5.6.1 Microcomputer

The microcomputer centers around the 8-bit 68809

microprocessor. The MPU has direct control over the

display, front panel switches, AID converter, IEEE488 bus,

5-8

PRINCIPLES OF OPERATION

as welI as the VOLTMETER COMPLETE Output and the

FXTERNAL TRIGGER Input. Timing for the micro-

processor is accomplished by the use of X01; an SMH!z

crystal. Internally, this frequency is divided~ down by four

to obtain a bus operating frequency ofZMHz.

Instrument operation software is stored in EPROMs U105

and U106. The revision level of this software is displayed

by Program 0 (Menu). Calibration constants, Translator

words and instrument set up conditions ati ~stti*d in

E*I’ROM (UlO8). Ul!l7 is the RAM. Partial address decoding

is use~d in this system. The function selected is d&en-n%

ed by the state of All, Al2, Al?, Al4 and Al5 address lines.

These address lines determine which is selected by the

decoders (U101). Only one device WOM, RAM, VIA, etc)

will have access to the data bus at any one time.

The heart of the IEEE-488 circuiixy is the GPIBA (Ull2). The

GPIBA is capable of performing aII IEEE talker-listener pro-

tocols. The bidirectional data lies DON through D7 permit

the transfer of data between the microprocessor and the

GPISA. The transceivers Ull3 and Ull4 are used to drive

the output. Data is buffered by Ull3 and U114 and iS

transmitted to the bus via connector Jl5.

5.6.2 Display Circuitry

The display information is sent through display latches UllO

and Ulll. Upon each display update, new segment~infor-

mation is presented to the display latches and a clock pulse

is sent on l”. The clock pulse to U4 and U5 (see schematic

196-116) shifts a digit enable bit to the next digit to be

enabled. Every 10 times the display is updated, a digit

enable it is generated at PA1 and goes to the data input of

the shift register. Ul28 through Ul.31 are the drivers for the

LED segments of the display digits tid the LED indicators.

5.7 POWER SUPPLIES

The main power supplies of the Model 196 are located on

sheet 1 of 2 of schematic drawing number 196-106. Fuse FlOl

is the line fuse which is accessible from the rear panel. 5102

is the POWER ON/OFF switch and SlOl selects ll5V or

230V operation by placing the transformer primary wind-

ings in parallel or series. The power transformer, TlOl, has

three secondary windings; one for the +5V digital supply,

one for the +5V analog supply and one for the kl5V analog

supply. CRlOl, CR102 and CR103 provide fullwave rectifica-

tion for the three supplies, while VRlOl through VR104 pro-

vide the regulation.

5-9/5-10

SECTION 6

MAINTENANCE

6.1 INTRODUCTION Table 6-1. Line Voltage Selection

This section contains information necessary to maintain,

calibrate, and troubleshoot the Model 196. Fuse replacement

and line voltage selection procedures are also included.

WARNING

The procedures included in this section are for

use onlv bv aualiffed service oersonnel. Do not

perform the& procedures unless qualified to

do so. Many of the steps in this section may ex-

pose you to potentially lethal voltages that

could result in personal injury or death if nor-

mal safety precautions are not observed.

6.2 LINE VOLTAGE SELECTION

The Model 196 may be operated from either lll5-l25V or

210~25OV 50 or 6OHz power sources. The instrument was

shipped from the factory set for an operating voltage

marked on the rear panel. To change the line voltage, pro-

ceed as follows:

WARNING

Disconnect the line cord and all other equip-

ment from the Model 196.

1. Place the line voltage switch, located on the rear panel,

in the desired position. See Table 6-l for the correct

position.

2. Install a power line fuse consistent with the line voltage.

See paragraph 6.3.1 for the fuse replacement procedure.

CAUTION

The correct fuse type must be used to main-

taln proper instrument protection.

3. Mark the selected line voltage on the rear panel for future

reference (to avoid confusion, erase the old mark).

Line Line Switch

Voltage Frequency Setting

105v-lzv 5OHz--6OHz lO5v-lz5v

21Ov-25Ov 50Hz-6OHz 21ov-25Ov

6.3 FUSE REPLACEMENT

The Model 196 has two fuses for protection in case of

overload. The line fuse protects the line power input of the

instrument and the current fuse protects the current func-

tion from excessive current. The fuses may be replaced by

using the procedures found in the following paragraphs.

WARNING

Disconnect the instrument fmm the power line

and from other equipment before replacing

fuses.

6.3.1 Line Fuse

To replace the line fuse, proceed as follows:

1. Turn off the power and disconnect the line cord and all

other test cables from the instrument.

2. Place the end of a flat-blade screwdriver into the slot in

the line fuse holder on the rear panel. Push in and rotate

the fuse carrier onequarter turn counterclockwise.

Release pressure on the holder and its internal spring

will push the fuse and the carrier out of the holder.

3. Remove the fuse and replace it with the proper type

using Table 6-2 as a guide.

CAUTION

Do not use a fuse with a rating higher than

specified or instrument damage may occur. If

the instrument repeatedly blows fuses, locate

and correct the cause of the trouble before

replacfng the fuse.

4. Install the new fuse and the carrier into the holder by

reversing the above procedure.

6-l

MAINTENANCE

Table 6-2. Line Fuse Replacement 6.4 CALIBRATION

I Line I I Keithlev

Voltage 1 Fuse %e ~~~~~ I p=cY6

9OV-125V 1/4A, 25OV, Slo-Blo, 3AG Fu-I7

18OV-250V 1 /SA. 250V. Slo-Blo. 3AG m-20

6.3.2 Current Fuse

Calibration should be performed every 12 months, or if the

performance verification procedures in Section 4 show that

the Model 196 is out of specification. If any of the calibra-

tion procedures in this section cannot be performed pro-

perly, refer to the troubleshooting information in this sec-

tion. If the problem persists, contact your Keithley represen-

tative or the factory for further informatxon.

The current fuse protects the 3CQA through 3A ranges from NOTE

an input current greater than 3A. To replace the current

fuse, perform the following steps: Check that the instrument is set to the proper line

frequency before proceeding with calibration.

1. Tuin off the power and disconnect the power line and

test leads. ~~ entjre &brafion procedure may be performed without

having to make any internal adjustments if high frequency

2. Place the end of a flat-blade screwdriver into the slot in

the fuse holder on the rear panel. Press in slightly and (701612) has been verified, as explained in paragraph 6.4.10,

step 5. Calibration can be performed from the front panel

rotate the fuse carrier onequarter turn counterclockwise. (Program 36) or over the IEEE-488 bus.

Release pressure and remove the fuse carrier and the

fuse.

3. Remove the defective fuse and replace it~using Table 6-3

as a guide.

CAUTION

Use only the recommended fuse type. If a fuse

with s higher current rating is installed, instru-

ment damage may occur.

NOTE

A ~“CONFLICT” error will be displayed, and the

CONFLfCT error bit in <he Ul status word will be

set when trying to calibrate the instrument while

it is in an improper state (i.e. dB). Also, ifan

“UNCAK’ error occurs, be sure to check the line

frequency setting before performing calibration.

6.4.1 Recommended Calibration Equipment

4. To replace the fuse carrier with the fuse, reverse the pro-

cedure in step 2. Table 6-4 lists recommended calibration equipment. Alter-

nate equipment may be used as long as eqGp&ent accurxy

Table 6-3. Current Fuse Replacement is at least as good as the specifications listed in the table.

Fuse Type / Keithley Part No.

3A, 25OV, 3AG,~Normal-Blo / Fu-82

Fluke

Table 6-4. Recommended Calibration Equipment

Description

DC Voltage Calibrator -’

AC Voltage Calibrator

AC Power Amplifier

Current Calibrator

.,. ,~ ,~ ~, ._I~~ ~,,

Specification9

3Oomv, 3v, 3w, 3oov ranges *l5ppm

3oomv, 3v, 3ov ranges; 20% *0.10/o;

50&-2Old-h 0.02%; lO4lkHz -10.33%

300V range; 2OHz fO.l2%; 5OH.z-2OkHz

*0.049/o; lookHz fO.l%

3OOiL3MO ranges; fl5ppm; 30MQ

k32ppm; 3OOMfi +225ppm

3OOfi-3A ranges *0.025%

6-2

6.4.2 Environmental Conditions

Calibration should be performed under laboratory condi-

tions having an ambient temperature of 23°C +YC and a

relative humidity of less than 70%.

6.4.3 Warm-Up Period

Turn on the instrument power and allow it to warm up for

at least two hours before beginning the calibration pro-

cedure. If the instrument has been subjected to extremes

of ttimperahue or humidity, allow at least one additional

hour for the instrument to stabilize before beginning the

calibration procedure.

6.4.4 CAL ENABLE Switch

A switch, accessible from the front panel, disables or

enables front panel and IEEE-488 bus calibration. When the

switch is in the DISABLE position, calibration cannot be

performed. The following message will be briefly displayed

when attempting to enter the caliiration program while the

switch is disabled:

CAL LOCKED

Calibration can only be accomplished with the calibration

switch in the ENABLE position.

The switch operates in the same manner as the power

switch and is accessed from the front panel with a small

bladed screwdriver. In the “out” positioti, klibration is

disabled and in the “in” position, calibration is enabled.

6.4.5 Front Panel Calibration

The following information provides the basic procedure for

calibrating the instrument from the fro&panel. A detailed

calibration procedure is located in paragraph 6.4.7.

1. Place the calibration switch to the ENABLE position

to enable calibration. The switch is accessed from the

front panel of the instrument.

2. Select the function and range to be calibrated (DCV,

Am, 61, DC4 or ACA).

3. Select the front panel calibration program as follows:

A. lkss the PRGM button. The following message will

be displayed:

PROGRAM ?

B. Enter Program 36 by pressing the 3 and 6 buttons.

The following message will be displayed briefly:

CAL=

C. The defaukcalibration point, which is a high end

reading for the selected range and function, will now

be displayed. Pororpxample, if the 3V DC range was

selected in step 2, the following calibration point will

be displayed:

3.oooow VW

4. If a different calibration point is to be used, enter the

new value using the data buttons (0 through 9). Each

press of a data button displays the number at the cur-

sor location (identified by the bright flashing digit), and

moves the -or to the n&digit. Jf the cursor is moved

past the least significant-digit, it-will move back to the

most~sigtiicant digit.

5. Comieti the calibration signal to the instrument.

6. Preis the ENTER button. The following message will

be displayed for several seconds:

WORKING

Z The low end calibration point will now be displayed.

For the 3VDC range, the following calibration point will

be displayed:

0.000000 VDC

Note: Calibration can be aborted with either the first

or second calibration point~prompt displayed by press-

ing the PRGM button. The instrument will leave the

calibration program without changing the previous

calibration constants.

8. If a calibration point other than the one displayed is toes

be used, then change the display to the desired value

as explained in step 4.

9. Set the level of the caliiration signal to agree with the

displayed calibration point;~

10. Press the ENTER button. The following message will

be displayed for several seconds:

WORKING

11. The two calibration points will be stored in EYROM and

the instrument will now exit the &i&ration program.

Select the next range and fundion to be calibrated and

repeat steps 3 through 10.

NOTEz If the calibration sources has a~ offset; Set the

calibration points to agree with the actual output of the

source. For example, if the source has a l$I DC offset

on the 300mV DC range, set the calibration points for

3CO.OOlOmV and 000.0010mV.

6-3

6.4.6 IEEE-468 Bus Calibration

IEEE-488 bus calibration is performed in a manner similar

to front panel calibration, except that calibration constants

are transmitted over the bus instead of being entered from

the front panel. By combining appropriate IEEE-488 com-

patible caliiation equipment with a suitable test program,

calibration of the Model 196 could be performed on an

automated basis. Refer to Section 3 for complete informa-

tion on using the IEEE-488 bus. The following information

provides the basic procedure for calibrating the ins-ent

over the IEEE-488 bus. The detailed calibration procedure

starts with paragraph 68.7.

Use the following basic procedure when calibrating the

Model 196 over the IEEE488 bus:

1. Place the csliiration switch to the ENABLE position. The

switch is accessed from the front panel of the Model 196.

2. Program the desired range and function over the bus.

For example, to select the 3OOV DC range, send FOR4X.~

3. The high end of the range is calibrated first. Apply a full

range (or near full range) calibration signal to the input

of the instnnnent. For example, for the 3oOV DC range,

apply 3OOV DC to the instrument.

4. Send the required calibration value preceded by the V

command letter and followed by the CO calibration com-

mand. For example to calibrate the 3OOV DC range at the

300V calibration point, send V3OOXCOX. ~~~~

NOTE: Calibration can be aborted at this time by sen-

ding an SDC or DCL comman d over the bti.~TheC&bra-

tion constant sent in step 4 will not be stored in E’PROM.

5. The low end of the range is calibrated next, Apply a zero

(or near zero) csliiration signal to the input of the in-

strument; For example, for the 3OOV DC range apply OV

to the instrument.

6. Send the appropriate calibration cornman ds for the sec-

ond calibration point. For example, to calibrate the zero

calibration point of the 3OOV DC range send VOXUX.

Note that Cl is used for the second calibration point.

7. Storage of the two calibration points into E%‘RqM

automatically occurs when the second calibration com-

mand is sent.

8. Repeat steps 1-7 for the remaining ranges and functions.

HP-85 Progr amming Example-The following simple pro-

gram demonstrates how to calibrate the Model I.96 over the

bus. The program assumes that the instruments primary

address is ate Z

PROGRAM COMMENTS

10 REMIX&7~07

20FOR I=OTOi

30 MSF ’ ’ RPPLY CAL1

BRkTION SIGML 9

46DISF”ENTERCALI

ERATIDN

COMMAND3 ’

50 INPUT A9

60OUTPUT707;A$

70ENTER70iiBB

SODISPB5

90 NEXT~I

100 EMD

Send remote enable.

Set program for one loop.

Prompts for calibration

signal.

Prompt for command.

Input command string from

keyboard.

Send command string to

7.96.

Get a reading.

Display reading.

Loop back one time.

‘lb run the program, press the HP-85 RUN key. At~the first

set of prompts, apply a fuJl range (or near full range) caliira-

tion signal to the instrument, type in the corresponding

calibration co mmand and press the return key. The com-

puter CRT will then display the calibration value. At the

second set of prompts, apply a zero (or near zero) caliir-

tion signal tc-~the~ inshu~~nt, type in the corresponding

calibration command and press the return key. The com-

puter will display the calibration value and store both

calibration constants into EY’ROM.

6.4.7 Calibration Sequence

C&irate the Model 196 in the order presented in the

following paragraphs. The basic sequence is:

1. DC Volts calibration

2. Ohms calibration

3. AC Volts calibration

4. DC Current calibration

5. AC Corrent~calibration

6-4

6.4.8 DC Volts Calibration

To calibrate the DCV function, proceed as follows:

NOTE

For front panelcalibration,omitstep 4 of the follow-

ing procedure. For IEH3-488 bus calibration, omit

step 3.

l.Select the DCV function and the 3OOmV range.

2. Connect the DC calibrator to the instrument as shown

in Figure 6-l.

NOTE NOTE

Low level measurement techniques should be used Low level measurement techniques should be used

when calibrating the 3OOmV DC range. Refer to- when calibrating the 3OOmV DC range. Refer to-

paragraph 2.6.5 for low level measurement con- paragraph 2.6.5 for low level measurement con-

siderations. siderations.

3. For front panel calibration, select Program 36 and pro-

ceed as follows:

A. With the 3OO.OOOOmV DC calibration point displayed

on the Model 196, set the DC calibrator to output

+0.30000oov.

B. After allowing sufficient time for the calibrator voltage

to settle, press the ENTER button. The following

message will be displayed for several seconds:

WORKING

C. With the OONlOOOmV DC calibration poinf displayed,

set the DC caliiator to output O.OOOOOOOV.

E. The instrument will exit the calibration progrsm and

return to the 3OOmWC range.

E Repeat the procedures in step~3 for the remaining DCV

ranges using Table 6-5 as a guide.

4. For IEEE488 bus calibration, proceed as follows:

A.Set the DC voltage calibrator to output +030000OOV.

B. After allowing sufficient time for the caliirator voltage

to settle, send the following commands over the bus:

V300E-3XCOX.

C. Set the DC voltage calibrator to outputs O.OOOOOOOV.

D. After allowing sufficient time for the calibrator voltage

to~settle, send the following comman d over the bus:

VOXClX. Both calibration constants will be

automatically stored in EzPROM.

E. Repeat steps A through D for the remaining DCV

ranges using Table 6-5 as a guide.

Figure 6-1. DC Volts Calibration Configuration

(300mV and 3V Ranges)

D. After allowing sufficient time-for the caliirator voltage 1

to settle, press the ENTER button. The following

message will be displayed for several seconds: Figure 6-2. DC Volts Calibration Configuration

(3OW3OOV Ranges)

WORKING

Table 6-5. DC Volts Calibration

Set-Up

Figure 6-l

Figure 6-2

IEEE&8

Bus Command

VJBOE-3XCOX

voxclx

v3xcox

voxclx

V3OXCOX

voxclx

6.4.9 Resistance Calibration E. The instrument will exit the calibration program and

return to the 30061 range.

To calibrate the ohms (Q) function, proceed as follows: F. Repeat the procedures in step 3 for the remaining

ohms ranges using Table 6-6 as a guide.

NOTE

For front panel calibration, omit step 4 of the follow-

ing procedure. For IEEE-488 bus calibration, omits

step 3.

4. For IEEE-488bus calibration, proceed& follows:

A. Set the resistance calibrator to 19Ohl.

B. After allowing sufficient time for the resistance

calibrator to settle, send the following commands over

the bus: Vl9OXCOX.

C. Set the resistance calibrator to SHORT (00).

1. Select the ohms function and the 300Q range.

2. Connect the resistance calibrator to the instrument as

shown in Figure 6-3.

3. For front panel calibration, enter Program 36; and pro-

teed as follows:

A. With the 190.00003 calibration uoint disulaved on the

D. After sIlowing sufficienttthne for the resistance

caliirator to settle, send the following command over tle, send the following command over

the bus: VOXClX. Both calibration constants will be

X. Both calibration constants will be

~lautomatically stored in ElPROM. tored in ElPROM.

E. Repeat steps A through D for the remaining ohms through D for the remaining ohms

ranges using Table 6-6 as a guide. able 6-6 as a guide.

Model 196, set the resistancecalibrato~ to 1900.

B. After allowing sufficient uptime for the c&&or

resistance to settle, press the ENTER button. The

following message will be displayed for several

seconds: RESISTANCE

WORKING CALIBRATOR

tlODEL 5450A

C with the OCQoooOR calibration point displayed, set the

resistance calibrator to SHORT (On). I

D. After waiting sufficient time for the calibrators

resistance to settle, press the ENTER button. The

following message will be displayed for several Figure 6-3. Four-Wire Resistance Calibration

Configuration (300&30kQ Ranges)

WORKING

396 Rang< Set-Up

300 n Figure 6-3

3k B Figure 63

30 kll Figure 6-3

300 kB Figure 63

3M1-2 Figure 6-4

3OMhl Figure 6-4

3OOMQ Figure 6-4

Table 6-6. Resistance Calibration

196 ~calibratiot

Point

190.0000 n

000.0000 n

1.900000 k0

O.OCGLXIO khl

l%OOoOO kS

00.00000 kB

l9O.OOL?4 kQ

000.0000 kO

1.9ilOCOOMR

O.OOOBOOMS

19.oOOOOM~

OO.OOOCOMD

lOO.OOOM62

OOO.OOOMO

1 Resistance

Calibrator

Setting

19OQ

Short (OS)

1.9kB

Short (OR)

19kbl

Short (On)

19OkS

Short (OR)

1.9MQ

Short (Obt)

19MB

Short (On)

100MR

Short (OS)

IEEE-488

Ius Commands

vl9oCxox

voxclx

v1.9E3xcox

voxclx

v19E3xcOx

VOXClX

Vl90E3XCOX

voxclx

Vl.9E6XCOX

voxclx

Vl9E6XCOX

voxclx

Vlo0E6XCOx

voxclx

6-6

MAINTENANCE

OUTPUT

MODEL 196 CABLE

Ik---7

OUTPUT LO ---

Figure 6-4. Two-Wire Resistance Calibration

Configuration (300kS300Mhl

Ranges)

3. For front panel calibration, select Program 36 and pro---

teed as follows:

A. With the 3OO.OOOmV AC calibration point displayed

on the Model 196,~ set the AC calibrator to output

3OO.Ouomv at 5ooHz.

B. After allowing sufikient time for the caliiator voltage

to settle, press the ENTER button. The following

message will be displayed for several seconds.

WORKING

C. With the 03O.OOOmV AC calibration point displayed,

set the AC calibrator to output 3O.OOOmV at 5OOHz.

ED. After allowing the calibrator voltage to settle, press

the ENTER button. The following message will be

displayed for several seconds:

WORKING

A full caliiration of the ACV function includes two inter-

nal, manual adjustments. However, if high frequency is

checked and found tobe within the specifications, then the

internal adjustments on the 30VAC and 3GOVAC will not

have to be done. The following procedure includes these

checks. The flowchart in Figure 6-5 helps clarify the calibra-

tion procedure.

E. The instrument will exit the calibration program and

return to the 3GOmV AC range.

F. Repeat the procedures in step 3 for the remaining

ACV ranges using Table 6-7 as a guide.

~4. For IEEE-488 bus calibration, proceed as follows:

A. Set the AC voltage calibrator to output 3OG.OGQmV at

5ooHz.

6.4.10 TRMS AC Volts Calibration

NOTE

For front panel calibration, omit step 4 of the follow-

ing procedure. For IEEE-488 bus calibration, omit

step 3.

BrAfter allowing sufficient time for the calibrator voltage

to settle, send the following commands over the bus:

V3OOE-3XCOX.

C. Set the AC calibrator to outputs 3O.OOOmV at 5OOHz.

D. After allowing sufficient time for the calibrator voltage

to settle, send the following command over the bus:

V30E-3XClX. Both calibration constants will

automatically be stored in FPROM.

E. Repeat steps A through D for the remaining ACV

ranges using~ Table 6-7 as a guide.

1. Select the ACV function and the 300mV range.

2. Connect the AC calibrator as shown in Figure 6-6.

Table 6-7. TRMS AC Volts Calibration

l96 ACV I996 Calibration AC Calibrator Voltage

Range Point Setting @ 5ooHz

3GGmV 3GO.OOOmV 3GG.OWmV

03O.OoOmV 3o.oOOmv

3 v 3.00000 v 3.OOWO~ v

0.30000 v .3ocaoo v

30 v 30.0000 v 30.0000 v

3.0000 v

?iooooo v

300 v 300.000 V 300.000 v

30.000m v 30.0000 v

IEEE-488

Bus Commands

VJOOE-3XCOX

V3OE-3XClX

v3xcGx

KKK&3XClX

v3GxcGx

v3xclX

v3oGxcGx

v3oxclx

6-7

MAINTENANCE

5. High Fmquency Check (7OkHZ):

A. With the ACV function, autorange and 5%d resolu-

tion selected, connect the AC calibrator to the instru-

ment as shown in Figure 6-6.

B. Set the AC caliirator to output XXXCW at a frequency

of 70kHz and allow sufficient time for the measure-

ment to settle.

C. If the reading is not 1oo.oooV fl500 counts, then omit

steps D through E and proceed to step 6.

D. Set the AC calibmtor to output M.OOilOV at 7OkI-k and

allow the measurement to settle.

E. If the reading is not lO.KKHN fl500 counts, then high

frequency will have to be adjusted as explained in the

following procedure (step 6). If the high frequency

readings were within the defined range, step 6 does

not have to be performed and ACV calibration is

completed.

6. High Frequency Adjustment:

A. Remove the top cover to gain access to the

adjustments;

B. With the ACV function and 5%d resolution selected,

connect the AC calibrator to the instrument as shown

in Figure 6-6.

C Set the Model 196 to the 300V range and set the AC

calibrator to output lOO.OWV &a frequency of 7OkHz.

WARNING

Some procedures require. the use of high

voltage. Take cam to prevent contact with live

circuits which could cause electrical shock

resulting in injury or death. The shield on the

analog board Is at input low potential and may

have up to 5OOV on it. Use an insulated align-

ment tool to make the following adjustments.

START

PERFORM FRONT

PANEL OR IEEE

CALIBRATION.

STEP 3 OR 4

CHECK HIGH CHECK HIGH

FREQUENCY FREQUENCY

(IOOKHI). STEP 5 (IOOKHI). STEP 5

ADJUST TRIM ADJUST TRIM

CAPACITORS CAPACITORS

STEP 6 STEP 6

Figure 6-6. Flowchart of AC Volts Calibration

Procedure

D.~ After allowing sufficient time for the measurement 1

to settle, use &insulated alignment tool to adjust C49

(see Figure 62’) for a display reading of loolMw ~50

COUd.9.

E. Set the Model 196 to the 3OV range and set the AC

caJ.ibrator to output l!mGoGv at 7GkI-k

E After allowing the measurement to settle, adjust C48

for a display reading of lO.OoooV f250 counts.

G. Repeat steps C through F until no other adjustments

need to be made.

H. Put the top cover back on.

HI POWER

AMPLIFIER AC VOLTAGE

CALIBRATOR

MODEL 5200A

Figure 6-6. TRMS AC Volts Calibration

Configuration

6-6

MAlNTENANCE

ANALOG BOARD SHIELD

BODVAC RANGE

HIGH FREPUENCY ADJUST

30VAC RANGE

ANALOG BOARD

Figure 6-7. TRMS AC Volts High Frequency Calibration Adjustments (30V & 300V Ranges)

6.4.11 DC Current Calibration C With the OCO.000~ DC caliiation point displayed,

set the current calibrator to output 000.000~.

Perform the following procedure to calibrate DCA:

NOTE

For front panel calibration, omit step 4 of the follow-

ing procedure. For IEEE-488 bus calibration, omit

step 3.

1. Select the DCA function and the 30&4 ranpe.

2. Cmnect the DC cwrent~cslibrator to the instrument as

shown in Figure 6-8.

3. For front panel c&ration, enter Program 36 and pro-

ceed as follows:

A. With the 304ICKKl~ DC calibration point displayed on

the Model 196, set the current calibrator to output

+300.000&4.

B. After allowing sufficient time for the ~~easmwnent

to settle, press the ENTER button. The following

message will be displayed for several seconds:

D. After allowing sufficient time for the measurement

to settle, press the Eh!TER button, The following

message will be displayed for several seconds:

WORKING

E. The instrument will exit the calibratioriprogram and

return to the 3OOfi range.

E Repeat the procedures in step 3 for the remaining

DCA ranges using Table 6-8 as a guide.

4. For IEEE-488 bus calibration, proceed as follows:

A. Set the current w&i&or to output 3OO.ooO~.

B. After allowing sufficient time for the calibrator cur-

rent~tb settle, sends the following command over the

bus: V3OOE6XCOX.

C. Set~th$ current calib+n to output 0OO.000~.

D. After allowing sufficient~ time for the calibrator cur-

xnt to settle, send the following command over the

bus: VOXClX. Both calibration constants will

automatically be stored in EzPROM.

E. Repeat steps A through D for the remaining DC4

ranges using ‘i%ble 6-8 as a guide.

6-9

MAINTENANCE

Table 6-8. DC Current Calibration

l96 Calibratior

Point

300.000 jL4

000.000 &4

3.oooooni4

o.ooooomA

3o.ooooIn4

00.0000n-A

3OO.ooonL4

ooo.ooonL4

3.00000 A

0.00000 A

DC Current

Calibrator Out ut

300.000~~1A

000.000 JIA

3.ooOOom4

0.00000d

3o.OOaomA

oo.oooonL4

3oo.ooonL4

000.000d

3ooo.ooIm4

oooo.oom4

IEEE-P&3

Bus Commands

V300E-6XcOX

voxclx

V3E-3XCOX

voxclx

V30E-3XCOX

VOXClX

KJOOE-3XCOX

voxclx

V3XCl.X

voxux

_. .-B. After waiting sufficietit~time for the measurement to

settle, press the ENTER button. The following

message will be displayed for several seconds:

WORKING

MODEL 196 C. With the 03O.ooOfi AC calibration point displayed, set

the current calibrator to output 030.000~ atm5OOHz.

Lo INPUT Lo DC VOLTAGE

CALIBRATOR CALl0RATOR

- flODEL 2500E HI ,NPUT “I MODEL 5440h

D. After allowing the measurement to settle, press the

ENTER button. The following message will be

displayed for several seconds:

WORKING

E. The instrument will exit the calibration program and

Figure 6-8. DC Current Calibration Configuration

6.4.12 TRMS AC Current Calibration

Perform the following procedure to calibrate the ACA

funcdon:

NOTE

For front panel cslibratiori, omit step 4 of the follow-

ing procedure. For IEEE-488 bus calibratioti; omit

step_3.

1. Select the ACA function and the 3OOfi range.

2. Connects the AC current calibrator to the instrument as

shown in Figure 6-9.

3. For front panel calibration, enter Program 36 and pro-

ceed as follows:

A. With the 3OO.OOOfi AC calibration point displayed on

the Model 196, set the current calibrator to output

300.000~ at a frequency of 5OOHz.

return to the 3UO+ range.

F. Repeat the procedures in step 3 for the remaining ACA

ranges using Table 6-9 as a guide.

4. For IEEE-488 bus calibration, proceed as follows:

A.Set the current calibrator to output- 3OO.OOOfi at

5ooHz.

B. After allowing sufficient time for the calibrator cur-

rent to’settle, send the following command over the

bus: V300E-6XCOX.

C.Set the current calibrator to output 03O.OOOfi at

5ooHz.

D. After allowing sufficient time fOl the calibrator CUT-

rent t&settle, &nd the following cornman d over the

bus: V30E-6XClX. Both calibration constants will

automatically be stored in E*l?ROM.

E. Repeat steps A through D for the remaining ACA

ranges using Table 6-9 as a guide.

NOTE

After completing the calibration procedure, place

the csliiration switch in the disable (out) position

Also, it is a good idea to place a dated calibration

sticker over the switch access hole.

6-10

MAINTENANCE

Table 6-9. TRMS AC Current Calibration

,; _ ~.~

196 ACA 196 Calibration Current Calibrator IEEE488

Range Point Out@ @~ 5@IHz Bus Commands

300&i 3OO.ooopA 300.000 pA v3ooE-6xcOX

030.000 PA’ 03o.DoopA v3OE-6XClX

3mA 3ooooomA 3.ooooomA V3E-3XCOX

0.30OOOclA 03000mA v300E-6XclX

3omA 3o.oOOomA 3o.oooomA V3OE-3XCOX

03.0000mA 03.0000IiL4 V3E-3XClX

3OOmA 3oo.ooomA 3oo.ooomA V300E-3XCOX

o3o.ooom4 030.000n4 V3OE-3XClX

V3XCOX

0.30000 A 03oo.OOidi WOOE-3XClX

Note: When installing the top cover make sure that

the three tabs at the front of the cover engage in the front

panel assembly. Also make sure that the ground clips

at the rear of the inshument make contact to the top

cover shield.

2. Analog board removal:

C. Disconnect the front and rear panel input terminal

wires (Il-JlO) at the analog board.

D. Unplug the connector (JV) that connects the analog

board to the mother board. This connector is located

Figure 6-9. AC Current Calibration Configuration

6.5 DISASSEMBLY INSTRUCTIONS

If it is necessary to remove or replace a component, use

the following procedure and refer to Figures 6-10 and 6-11

to disassemble the Model 196. Note that each step of~the

procedure is dependent upon performing the step before

it. To reassemble the instrument, reverse the procedural

steps.

WARNING

To prevent a shock hazard, always turn the in-

strument off and disconnect the line cord and

all other instrumentation from the unit before

removing the top cover.

1. Top cover removal:

A. Remove the top two retaining screws located at the

rear of the instrument.

B. Grasping the top cover at the rear, carefully lift it off

of the instrument;

at the front of the analog board.

E. Cakefully lift the analog board off of the mounting

plate.

3. Analog board mounting plate removal:

A. Remove the four screws securing the mounting plate

to the case.

B. Carefully lift the mounting plate off the four

standoffs.

4. Mother board removal:

A. Pull out the four standoffs used to support the

gmlog board assembly.

B. Remove the two screws at the rear panel that secure

the rear panel to the case.

C. Dikonnkt the ribbon cable that connects the display

board to the mother board.

D. Grasp the rear panel and the mother board, and

gently lift the mother board up and out of the case.

Note: When installing the mother board, make sure

&e ground clips make contacts with the bottom

shield, and the display ribbon cable is properly

mated to the mother board connector.

5. Display board removal:

6-11

A. Remove the two screws that secure the front panel

assembly to the case. These screws are locate~d near

the bottom edge of the display PC board.

B. Slide the fmnt panel assembly up and out of the case.

C. Remove the two screws that secure the display board

to the front panel.

D. Separate the display board from the front panel.

Note When MtalXng the front panel assembly in the

case, make sure the bottom edge of the~display PC

board is positioned between the card guide-s at the

bottom of the case.

57. l l l JB

J6 J9

JiO

ANALOG BOARD

J4J3 52 Jl

Js... . .

J17

6.6 SPECIAL HANDLING OF STATIC-

SENSITIVE DEVICES

CMOS devices operate at very high impedance levels for

low power consumption. As a result, any static charge that

builds up on your person or clothing may be sufficient to

destroy these devices, if they are not handled properly.

Static-sensitive devices are flagged in the replaceable parts

lists in Section Z When handling these devices, use the

following precautions to avoid damaging them.

1. The devices listed in the replaceable parts list should be

transported and handled only in containers specially

designed to prevent static build-up. Typically, these parts

will be received in anti-static containers of plastic or foam.

Keep these devices in their original containers until ready

for installation.

2. Remove the devices from their protective containers only

at a properly grounded work station. Also ground

yourself with a suitable wrist strap.

3. Handle the devices only by the body; do not touch the

pins.

4. Any printed circuit board into which the device is to be

inserted must also be grounded to the bench or table.

5. Use only anti-static type solder suckers.

6. Use only grounded tip solder irons.

7. Once the device is installed on the PC board, it is nor-

mally adequately protected and normal handling can

resume.

6.7 TROUBLESHOOTING

The troubleshooting information contained in this section

is intended for use by qualified personnel having a basic

understanding of analog and digital circuitry. The in-

dividual should also be experienced at using typical test

equipment as well as ordinary troubleshooting procedures.

The information presented here has been written to assist

in isolating a defective circuit or circuit section. Isolation

of the specific component is left to the technician. Note that

schematic diagrams and component location drayings,

which are an essential aid in troubleshooting, are located

at the end of Section 7.

Figure 6-10 Analog Board Connectors

6-12

MAINTENANCE

/- ANALOG BOARD

I I

MOUNTING PLAT

A w/ 1 ,-STANDOFFS(S)

f&v ,-MOTHER BOARD

Figure 6-11. Model 196 Exploded View

6-13

6.7.1 Recommended Test Equipment

Success in troubleshooting complex equipment like the

Model 1% depends not only on the skill of the technician,

but relies on the use of accurate, reliable test equipment.

Table 6-10 lists the equipment recommended for trouble-

shooting the Model 196. Other equipment such as logic

analyzers and capacitance meters could also be helpful,

especially in difficult situations.

6.7.2 Power Up Self Test

Upon power up, the instrument will do a number of tests

on itself. Tests are performed on memory (ROM, RAM and

E’FROM). Whenever one of the memory tests fails, the in-

skument will lock up and must be repaired. If all the tests

pass, then the current IEEE address and software revision

level of the inskument will be displayed. Immediately after

turning on the Model 196, the foll+ng sequence will take

place:

1. A digital check will be performed on the ROM circuitry.

If the test fails, the instrument will lock up with the

following message displayed:

0000000000

Replacing U105 and U106 may resolve the problem.

2. If the ROM test passes, a digital self-test will then be per-

fotied on the RAM circuitry. If the RAM test fails, the

instrument will lock up with the following error message

displayed:

AAAAAAAAAA

Replacing UKV may resolve the problem.

3. Finally, the E’PROM circuitry where the calibration con-

stants, IEEE address and line frequency settings are

stored will be checked. Jf this test fails, the following

message displayed:

UNCIAL

Pressing any front panel momentary button will return

the instrument to normal operation however, a complete

calibration will have to be performed, and the IEEE ad-

clress and line frequency setting should be checked. If

the test still fails after calibration, try replacing U108

before recaliirating the instrument again.

4. The instrument will then go to the power up default

function.

6.7.3 Program 33 - Self Diagnostic Program

This front panel program performs a display testand the

same memory tests performed upon power up. Also in-

cluded is a troubleshooting test mode, that is designed to

switch on various switching FETs and relays to allow signal

tracing through the instrument. Perform the following pro-

cedure to utilize Program 33:

1. press tl~e PRGM button and then the 3 and 3 buttons.

First is the display test. Segments of the c&play

characters will be sequentially displayed for a short

period of time. The front panel LEDs will also be on dur-

ing this test. This test allows the operator to note in-

operative display segments or LEDs. Self test-on the

ROM, RAM, and E2PROM ~III then be performed. These

are the same tests run on power up and are explained

in detail in paragraph 6.7.2.

- -_ -___._

Five function DMM with 0.1% basic DCV accuracy, 1OM

input impedance

-I-

Power supply and DC voltage checks;

analog signal tracing conti+ty, logic

levels.

Dual-trace, triggered sweep oscilloscope, DC to 5OMH.z Digital and analog waveform checks.

Digital frequency counter Checking clock frequencies.

Table 6-10. Recommended Troubleshooting Equipment

6-14

2. The Model 196 wiIl now go into the trouHesh+ing

mode with the first N mode being displayed as follows:

N 01

The instrument is still on the same function and mnge

as it was before Program 33 was ruti.

3. Using Table 6-11, reference the N mode to the current

function and range to determine the proper warking

status of the listed circuit components.

4. To change the N mode, use the ENTER button.

5.X0 troubleshoota different~ function tidlor ra@$e; exit

the program by pressing any front panel momentary but-

ton (except ENTER), select the desired function and/or

range and again run Program 33.

6.7.4 Power Supplies

Table 6-12 shows the various checks that can be made to

the power supplies of the Model 196. In addition to the nor-

mal voltage checks, it is a good~idea to check the various

supplies with an oscilloscope for signs of noise or

oscillations.

6.7.5 Signal Conditioning Checks

These circuits can be checked by using the diagnostic pro-

gram (Program 33) as explained in the paragraph 6.7.3.

6.7.6 Digital and Display Circuitry Checks

The digital and display circuitry can be checked out by us-

ing the troubleshooting data found in Tables 6-13 and 6-14.

Table 6-11. Model 196 Troubleshooting Mode

Function Input

& Measurement Buffer Relays Range Switches Multiplex

Range Phase N Mode Gain Closed Closed Switches Closed

300mV DC SIG ZERO 01 X10 Kl

CAL ZERO 02 Xl Kl :z ~~ U25::Q32

CAL 03 Xl Kl Qll: U22A LJUC, 432

SIG 04 X10 Kl Qll, U22A 430 ~~

3VDC SIG ZERO 01

CAL ZERO zz ;t :; QII, U22A 434

Q% Uzw U25D,mQ32

CAL Xl z QX U22A UUC,. 432

SIG 04 Xl Q% IJ~A 430

30VDC SIG ZERO kc g 1 Q13, QlL UZZJ. 433

CAL ZERO Q13, QlL IJZ.ZA U25D, 432

CAL z: Xl - 4% QU LJZL’. UUC, Q32

SIG Xl - Ql3, QU, U22A 435

300X7 DC SIG ZERO 01 Xl - Q3, QJ.L U22A Q34

CAL ZERO xl - Q3, QQ U22A~

CAL :z U25D; 432

Xl - Q3, QlL IJZA U25C, Q32

SIG 04 Xl - Q3, Qll, UZA 435

300mV AC ZERO ol Xl K4, K5 U2lA, U21B U25D, Q32

CAL 02 Xl K% K5 U2lA, U21B U25C, 432

SIG 03 Xl K4 ~5 u2L4, u2lB U24C, Q32

No Test 04 - - - -

3V AC ZERO ol ;: K4, K5 U21C ~~~~ U25D, 432

CAL W KS u21c

SIG ii u25c, Q32

Xl K4, K5 u21c U24C, 432

No Test 04 -~ - -

6-16

Table 6-11. Model 196 Troubleshooting Mode (Cont.)

CAL

SIG

No Test

N Mode

Input

Buffer

Gain

I -

300V AC ZERO ii 2 Ei U23C, U23B

CAL U23C, U23B

SIG 03 Xl K4 U23C, U23B

No Test 04 -~ - -

3OOcl SENSE LO In x10 K2, K3 Qll, U22D, U24Dm

iI% it : E% Qll, U22D, U24D

Qll, U22D, U24D

SENSE HI 04 xl0 K2: K3 Qll, U22D, U24D

3k SENSE Lo

REFHl

REFLO

SENSE HI

30k SENSE LO

SENSE HI

3OOK SENSE Lo

REFHI

REFU3

SENSE HI

3M SENSE LO

REFHI

SEE%

3ilM SENSE LO

SE%E%

No Test

300M SENSE Lo

SE%E%

No Test

3OOfi DC SIG ZERO

CAL ZERO

CAL

SIG

- I -

x10

Xl0

Qll, U22D, U24D

Qll, ~U22D, U24D

Qll, U22D, U24D

U22B, 432

4% Q=

U25A, 432

430

Qll, U22C, U24A U22B, 432

Q~ll, U22C, U244 Q35, 412

Qll, U22C, U24A U2W, 432

Qll, U22C, U24A Q30

Ql2,43, U22C, U24A

QZQ3, U22C, U24A

Ql2, 43, U22C, U24A

Ql.2, Q3, U22C, U24A

U22B, 432

Q35

412,413, U22C, U24A

QELQl.3, U22C, U24A

412, Ql3, U22C, U24A

Ql2, QU, U22C, U24A

U22B, 432

Ql2, U22.C, U244

Ql2, U22C, U24A

412, U22C, U24.4

U22B, 432

435

430

U23A

Multiplex

Switches Closed

U25D, 432~

U25C, 432

U24C, 432

U25D, 432

UUC, 432

U24C, Q32

U22B, 432

435, 412

U25A, Q32

U22B, 432

u25D, Q32

U25D, 432

U25C, 432

U24B. 032

6-16

MAlNTENANCE

Table 6-11. Model 196 Troubleshooting Mode (Cont.)

Function

Range

3mA DC

3OmA DC

3OOmA DC

3A DC

3OOfi AC

3mAAC

3OmA AC

3COmA AC

3AAc

Measuremen

P&E

SIG ZERO

CAL ZERO

CAL

SIG

SIG ZERO

CAL ZERO

CAL

SIG

SIG ZERO

CAL ZERO

CAL

SIG

SIG ZERO

CAL ZERO

CAL

SIG

ZERO

CAL

SIG

No Test

ZERO

CAL

SIG

No Test

ZERO

CAL

SIG

No Test

ZERO

CAL

SIG

No Test

ZERO

CAL

SIG

No Test

N &lo&

01~

z.i

IllpUl

3uffe

Gain

xl0

;;

Xl0

x10

Xl0

;;

x10

;;

- ~~

Range Switches

Closed

g? :.E

Q29: 436

42% 436

4% Q37 UUD, 432

428, Q37 UUD, 432

Q% 437 U25C, Q32

Q28, Q37 U24B, 432

U25D, 432

U2!5D, 432

U2.K Q32

UZ4B, 432

Q39, Q@

Q39, Q40

g; g::

UUD, Q32

U25D, 432

UUC, 432

U24B, Q32

u23A, u2lD, u2lB U25D, 432

U23A, U21D, U21B U25C, Q32

U23A, U2lD, U21B U24C, 432

- -

429, 436, U2lD, U21B

Q29, Q36, U21D, U21B

429, Q36, UUD, U2lB

Q28,437, U2lD, U2lB

Q28, Q37, U21D, U2lB

428, ~437, UZlD, U2lB

226, 438, U21D, U21B U25D, 432

226, Q38, U21D, U21B UWC, 432

326, 438, U2lD, U2lB U24C, 432

239, 440, U21D, U21B U25D, Q32

239, 440, UZlD, U21B U25C, Q32

239, 440, U219 UZlB U24C, 432

Multiplex

Switches Closed

U2SD, 432

U25D, 432

U25C, 432

U24B, 432

U25D, 432

UUC, 432

U24C, 432

UUD, 432

U25C, 432

U24C, Q32

6-17

Table 6-12. Power Supply Checks

Step ItemlCotipdnent Required Condition Remarks

1 SlOl Line Switch

2 FlOl Line Fuse Set to 115~ Or 23OV as required. Lie voltage selection

Check for~contimity. Remove fuse to check

3 Line Power Plugged intd live receptacle;

4 power on.

+5V Digital Supply VRllll, pin ~3 +5v, i5% Referenced to digital common

5 +5v Analog Supply VRlO2, pin 3 +5v, *5%

6 +l5V Analog Supplies VR103, pin 3; +lW, -UV, f0.75V Reference to analog common

vRlo4, pin 3 Referenced to analog common

Table 6-13. Digital Circuitry Checks

Step 1 Item/Component

1 U105, U106, U107, U108 ~.~

2~~

UlO9, pin 2 (PAO)

UlO9, pin 3 (PAl)

u109, pin 6.(PA4)

UlO9, pin 7 (I?A5)

U109, pin 8 (TA6)

UXl9, pin 9 @?47)

ulO9, pin 19

Ul20, pin 6

u43, pin l3

UlO9, pins 12 through 16

u104, pin 3

um4, pin 37

ull2, pin 9

I.5 Ull2, pin 19

16 UK!, pin 18

I7 Ull2, pin28

I8 Ull2, pins 28 @TN), 24 (NDAC),

25 (NRFD), 26 (DAV), and the data

lines

Required Condition

Pass RAM, ROM tid E’I’ROM

self-test on power up.

TTL level pulses~ every lmsec

lTL level pulses every l5msec

Switch data (+5V or OV)

Variable pulse train (OV to +5V)

lk.Hz pulses

+5V, *5%

+5V siznal pulsed OV to +5V

every GnseC

+5v (Logic “1”)

2MHz square wave at OV to +5V

Should go false (+5V) when

command is sent

Refer to Figure D-2 for required

conditions

Remarks

Display wilI lock if failure

occurs-

VIA clock

Data

Data input to VIA

VII Data Line

Data output

Output-of-A/D converter

Analog data to VL4

lRQ line

Reset line

lNTline

RESET lie

ClOCk

ATN line

Handshake sequence

6-16

MAINTENANCE

Table 6-14. Display Circuitry Checks

Step Item/Component Required Condition Rema “~

irks

1 U4 and US, pins 2,9 and 14 +5v, *5%. +5v

2 Pl6, pins 6, 11 through 24

3 Ul, pins 10 through 15;

Variable pulses supply

Variable pulses Segment drivers

U2, pins 13 through 16 Digital drivers

4 US, pins 3, 4, 5, 6, lo, 11 atid 12;

u4, pins 1, 3, 4? 5 lmsec negative going pulse every

1Omsec

5 I%, pin 7 (SO) Depress Sl, S2, S3, S4 or S5 button Pulse present when

6 l’l6, pin 5 (Sl) pressed

Depress S6, S7, S8 or S9 button Pulse pment when

7 P16, pin 3 (S2) Depress SlO, Sll, 512, SW Otis 514 pressed

button Pulse present when

pressed

button

6-19/6-20

SECTION 7

REPLACEABLE PARTS

7.1 INTRODUCTION 1. Instrument Model Number

2. Insrument Serial Number

This section contains replacement parts information, corn- 3. parts Description

ponent location drawings and schematic @agrams for the

Model 196. 4. Circuit Designation (if applicable)

5. Keithley Part Number

7.2 PARTS LIST

Parts are listed alphanumerically in order of their circuit

designations. Table 7-1 contains parts list information for

the display board. Table 7-2 contains parts list info~ati~n

for the digital board. Table 7-3 contains parts list informa-

tion for the anal0

f board. Table 7-4 contains a miscel-

laneous parts list or the Model 196.

Devices that are static-sensitive are flagged in the p&s lists

descriptions with the abbreviation SSD. Special handling

of these devices is explained in paragraph 6.6.

7.3 ORDERING INFORMATION

To place an order, or to obtain information concerning

replacement parts, contact your Keith@ representative or

the factory. See inside front cover for addresses. When

ordering include the following information:

If an additional instruction manual is required, order the

manual package (Keithley PartNumber 196-901-00). The

manual package contains an instruction manual and any

applicable addenda.

7.4 FACTORY SERVICE

If the instrument is to be returned to the facto y for ser-

vice, please complete the service form which follows this

section and return it with the instrument.

7.5 SCHEMATIC DIAGRAMS AND

COMPONENT LOCATION DRAWINGS

Schematic diagrams and component location drawings

follow the appropriate replaceable parts list for that par-

ticular board.

7-117-2

REPLACEABLE PARTS

Table 7-1. Display Board, Parts List

Circuit

Desig. Description

z Capacitor, lO@, 29, Al*um Elect@Ytic

Capacitor, O.lfl, SW

E Capacitor, o&z, SW

Capacitor, O.l& v

c5 capacitor, 0.1/s, 5Ov ~~

DSl-DS5 LED, Display, Dual !?+gment

DS6-DS16 LED, Pilot, Red

I’l6 Connector, Display Cable

51-514 switch

Ul IC, Darlington Translator Amy, 2003, SSD

is IC, Darlington Translator Array, 2003, SSD

IC, Hex Inverter, Open Collector Output; 74LSO5, SSD

E IC, 8-Bit Serial InPamlMQut Shift Register, 74HCIl64

IC, 8-Bit Serial In/Padlel Out Shift Register, 74HCIl64

Keithley

Part No.

c-31410

C-365-A

C-365-S

C-365-.1

DD-39

PL7l

CA-%6

SW-435

IC-206

IC-141

IC-456

K-456

7-3

REPLACEABLEPARTS

I I

Figure 7-l. Display Board, Component Location Drawing, Dwg. No. 196-110

7-4

, /

lm”l”l , “III1

REPLACEABLE PARTS

Table 7-2. Digital Board, Parts List

circuit

Desig.

Cl01

Cl02

a03

Cl04

Cl05

CiO6

cl07

cl08

a09

cllo

E.z

Cll7

Cl%

al9

cl20

u24

cl25

Cl26

EE3

CEO

cJ33

Cl34

Cl35

Cl36

Cl37

Cl38

cl39

Cl40

~~~

Cl43

Cl45

Cl46

Cl47

cl49

cl50

CEi

DescSption

Capacitor, lO,OOOpF, WV, Aluminum Ek&lyti~

C+kitor, lo& 25V, Aluminum Electrolytic

Capacitor, l500& 25V, Alumhm Elect++&

Capacitor, lo& 25Y Aluminum Electrolytic

Cap@or, 62O/cE; 35Y, Electrolytic

Capacitor, 62Ofi 25V, Electrolytci

Capacitor, lo& 25V, Aluminum Electrolytic

capacitor, l&F, WV, Aluminum Electrolytic

Not Used

Capacitor, o&F, 5ov

Capacitor, 0.19, 5OV

Not Used

CapaZtor, O&F, 50V ~~

Capacitor, O.&S, 5OV

Capacitor, O.l& SW

Capacitor, O&F, 5OV

Capacitor, IJ.l& 50V

Capacitor, O.&F, 5OV

Capacitor, iJl& 50V

Capacitor, O.l& 50V

Capacitor, o.ifl, 50V

Capacitor, O.lfl, SW

Cap&itor, O.l/LF,, 5W

Capacitor, l5pF, lO+JW, Ceramic Disc

Capacitor, l5pF, MOOV,~ Ceramic Diic

capacitor, o&z, 5w

Capacitoz lO& WV, Aluminum Electrolytic

Not Used

Capacitor, O.l& 5OV

Mot Used

Vot~Used

YotmUsed

Capacitor, O.l& 50V

zapacitor; o&F, SW

Capacitor, 47OOp,~ lOCW, Ceramic Disc

Capacitor, lo@, 25V, Aluminum Electrolytic

Zapacitor, O.l@, 5OV

Zapacitor, O.l@, 50V

Z+acitor, O&F, SW

Zapacitor, O.l@F, 50V

Vat Used

Zapacitor; O.lpF, 5W

Spkitor, X&E 25V, Aluminum Electrolytic

z3pacitor, O.l& SW

Uoi Used

~+%itOr, O.Olp.F, 5OOV, Ceramic Disc

Keitbley

Part No.

C-38%10,000

c-314-10

c-314-1500

c-314-10

C-309-680

c-314-10

C-365-.1

C-365-J

C-365-.1

c-365-.1

C-365-.1

C-64~l5p

c-64-15p

C-365-.1

c-314-10

C-365-J

C-365-.1

c-64-47oop~~

c-31w

C-365-.1

c-314-10

c-365-s

C-22-.01

7-8

REPLACEABLE PARTS

Table 7-21 Digital Board, Parts List (Cont.)

Circuit

De&g. Description Keithley

Part No.

cl52 Capacitor, o&F, 50v

cl.53 capacitor, o&F, 50v

CRlOl Diode, Bridge Rectifier, SA, ~rE05

CR102 Diode, Silicon, 1.5A, 4OOV, WO4M

CR103 Diode, Silicon, 1.5A, 4OOV, WO4M

CR104 Not Used

CR105 Diode, Silicon, lN4148

CR106 Diode, Silicon, lN4148

CR107 Not Used

CR108 Diode, Bridge Rectifier, L4, lOOPlV

FlOl Fuse, V,6A, 25a: 3AG, Slo-Blo

FM1 Fuse, ‘I,&, 25OV, 3AG, Slo-Blo

E Connector, 3-pin, Male

Connector, AC Line

;z Connector, Right Angle IEEE Mount Receptacle

Connector, 26-pm, Male

m7 Connector, Hotising, 8-pin, Female

Connector, Contact for lV

Rl!Jl Resistor, Thick Film

R102 Resistor, Thick Film

R103 Resistor, Thick Film

Rlo4 Resistor, Thick Film

Rlo5 Resistor, Thick Film

R106 Resistor, 60.4k, l%, ‘leW, Composition

R107 Resistor, llSk, l%, ‘/,W, Composition

R108

R109 Resistor, 26lkQ l%, ‘&W, Composition

Not Used

RlM Not Used

Rlll Resistor, 1o(M2, 596, XW, Composition

RllZ

Rll3 Resistor, 3.3k0, 5%, %W, Composition

Rll4 Resistor, 1004 5%, VrW, Composition

Resistor, lM0, lo%, XW, Composition

FE Not Used

Not Used

Rll.7 Not Used

Rll8 Not Used

Rll9 Not Used

RI20 Resistor, lkfl, 5%, v4W, CornpositiOn

RI21 Not Used

rim Resistor, 2&n, 5%, ‘hW, CompositibT

E Resistor, lOOQ, 596, Yaw, Compositioti

Resistor, 47Q 596, y4W, Composition _

Rl25

R126 Resistor, 4700, 5%, XW, Composition

RlW Resistor, lOOQ 5%, YPW, Composition

Resistor, 2.4kfl, 5%, +bW, Composition .--I

RI.28 Resistor, lk0, 596, ‘/aW, Coxnposition

c-365-.1

Q&.1

RF-48

RF-46

RF-28~

RF-28

RF-52~

Fu-29

FU-40

CS-288-3~

CS-388

CS-507

CS-389-3

CS-287-8

CS-276

n-141

w-141

v-77

Tl-77

TF-140

R-88-60&

R-88-11.8k

R-88-261k

R-76-100

R-763.3k

R-76-100

R-7&l&4

R-76I.k

R-76-2&

R-76-100

R-76-47

R-76-470

R-76X0

R-76-2&

R-76-Xx

7-9

REPLACEABLE PAATS

Table 7-2. Digital Board, Parts List (Cont.)

CiIcuit

Desig. Description Keithky

Part No.

Rl29 Resistor, 47Q 5%, ‘IPW, Composition R-76-47

Rl30

Rl31 Resistor, 1000, 596, VaW, Composititin R-76-100

Resistor, 2.4k61, 5%, VaW, Composition R-76-2&

RI32 Resistor, lkQ, 5%, ‘/aW, Composition R-76-lk

i%i Resistor, 47% 5%, ‘/rW, Composition R-76-47

Resistor, lOOf& 5%, XW, Cotiposition R-76-100

R335 R-76-2&

RI36 Resistor, 2.4k62, 5%, v4W, Composition

Resistor, lk61, 546, ‘/aW, Composition R-76-lk

RI37 Resistor, 47Q 596, YiW, Composition R-76-47

RI38 Resistor, 4704 5%, I/qW, Cotiposition R-76-470

E Not Used

Not Used

% Resistor, 82Q, 5%, XW, Composition R-76-82

Resistor, 82tl, 5%, XW, Composition R-76-82

R143 Resistor, 820, 5%, ‘/rW, Composition R-76-82

SlOl Switch SW-318

s102 Switch SW-466

9.03 Switch SW-439

Tlol Transformer, Line, American TR-249

TIol Transformer, Lime, Japanese .~ lx-250

TIO2 Transformer, Pulse TR-231

E Transformer, Pulse TR-231

Transformer, Pulse TR-231

T105 Transformer, Pulse TR-231

Kz IC, &al IO-Input AND/OR/INVERT Gate Army, PALlOL8, SSD IC-514

u103 I&QI~~~ Z-Input NOR Gate, 74HcTo2, SSD K-510

U104 IC, ~8Bit Microprocessing Unit, 68BO9 LSI-65

ulO5 IC, l6k x 8’UV Erasable PROM, 27128; SSD 196-801~

Ez IC, ‘l6k x 8 UV Erasable PROM, 27l.28; SSD 196-800-’

IC, 8192 Word x 8-Bit Static CMOS RAM, 6264LF-15 LX-66

EE IC, Progfamma ble E’ROM, 2816A LSI-83

IC, Versatile Interface Adapter (VJA), 6522 LSI-45

ullo IC, C-MOS T&State Flip-Flop, 74HCI374, SSD IC-397

Ulll IC, C-MOS Tri-State Flip-Flop, 74HCT374, SSD IC-397

:Ei IC, GPIB Adapter, 9914 ~~~ LSI-49

IC, Octal GLIB Transceiver, 75160A IC-298

ul14 IC, Octal GPIB Transceiver, 7516L4 IC-299

Ull5 IC, Micropower Bipolar Monolithic, 8211, SSD IC-177

Ull6 Not Used

Ull7 Not Used

~~ Not Used

Not Used

*Order same software as presently installed. For example, if the software revision level is B8, then order 19680088

and 196:801-B8.

7-10

REPLACEABLEPARTS

Table 7-2. Digital Board, Parts List (Cont.)

circoit KeithIey

Desig. Description ~, Part No.

UT20 IC, Quad 2-Input NAND Gate, 74HcO0, SSD

ul21 Not Used

Ul22 Not Used

E IC, Dual 4-Bit Decade and Binary Counter, 74LS393, SSD

IC, Comparatbr, LT31lA, SSD

Ul25 IC, Voltage Comparator, LM311, SSD

% IC, Voltage Comparator, LM311, SSD

IC, Voltage Comparator, LM311, SSD

U128 IC, Transistor Array, MPQ3906

ul29 IC, Transistor Array, hPQ3906

UT30 IC Transistor Array, MPQ3906

Ul31 IC, Transistor Array, MPQ3906

VRlOI Regulator, IC,~ +5V, 309

VRlO2 Regulator, IC, +5V, 7805

VR103 Regulator, IC, +l5V, 78Ml.5

VR104 Regulator, IC, -WV, 79Ml5

VRlO5 Regulator, Diode, Silicon, lN702A

VRlO6 Regulator, Diode, Silicon, lN702A

MO1 Crystal, 8MHz ~,I”-.-.-~~ _ _~~ .~...

IC-351

IC-213

IC-526

IC-173

:::Fz

IC-396

IC396

IC-396

::g

32472-l

32472-2

DZ33

CR-24-l

7-11

REPLACEABLE PARTS

u’

Figure 7-3. Digital Board, Component Location Drawing, Dwg. No. 196400

7-12

REPLACEABLE PAFITS

I c I 0 1 E I F

Figure 7-4. Digital Board, Schematic Diagram, Dwg. NO. 19;6-106 (sheet 1 of 3)

7.13lh1.4

I--

REPLACEABLEPAFITS

Table 7-3. Analog Board, Parts List

Circuit

Desig. Description Keithley

Part No.

Cl1

Cl4

cl5

C24

c25

0.6

C43

C44

C45

C46

C47

C48

c49

Capacitor, 33Op, 50V

Capacitor, O&F, 50V

Capacitor, O$F, 50V

Capacifor,~ 0.$X 50V

Capacitor, O.l& 50V

Capak, O.l& 50V

Not Used

Capacitw O&F, 50V

Capacitor, O.l& 50V

Capacitor, O.lpF, 50V

capacitor, O.lfAF, 5ov

capacitor, O.&F, 5ov

Not Used

capacitor, O.lfLF, 5w

Gpacitor, O.l& 50V

capacitor, O.l& 5OV

Capacitor, O&F, 5OV

CapBcitor, O.i$, 50V

Capacitor, 0.18 50V

Capacitor, O&F, SOV

Capacitor, O.&F, 50V

Capacitor, O&F, 50V

Capacitor, O.l& 50V

Not Used

Capacitor, O.&Z, 50V

Camcitor. O.luE 50V

Capacitor,

Not-Used

Capacitor,

Not Used

Capacitor,

capacitor,

Cauacitor,

o.i& 50~

c-365-.1

C-365-A

C-365-.1

82pF, lOOW, Ceranik Disc

l5pF, lOOW, Ceramic Disc C-64-82~

I50pE low, Ceramic C-64J5p

0.0047& IOW, Metaliied Polypropylene C-372-150~

C-306-.0047

lo& 25V, Aluminum Electrolytic c-314-10

33pF, loOW, Cerainic Disc

33pF, lOOW, Ceramic Disc C-64-33~

330pF, ‘IOOW, C&amic Disc C-64-33~

330pF, lOOOV, CeramkDisc C-64-330~

680pF, 5OOV, Polystyrene c-64-330p

c-us-68Op

O&F, 63W, ~Metalized Polyester

lopF

15pF, 5OV, Tubular Ceramic

llOuE 5OoV Mica

c-364-.1

C-372-10~

C-282-1.5~

c-278~llop

c-204-15

C-2942

c-350-m

c-350-1

c-359

c-345

c-22s.ow

c-221-.015

ca&2itor, l5$, -2OV, Tantalum

Capacitor, +F, lOOV, Polyester

Capacitor, 0.47@, 5OV, Metalized Polyester

Cqjacitor, l& 5OV, Metalized l%lyester

Capacitor, Trimmer, 2.5pF to 6pF, 500V

Capacitor, Trimmer, 4pF to 4OpF, 500V

Capacitor, O.&F, ZCiOV, Polycarbonate

Capacitor, O.W@, ZOW, Polycarbonate

ca33op

C-3657.1

C-365-S

C-365.1

C-365-A

c-365-.1

C-365-.1

c-365-.1

C-365-.1

C-365.1

C-365-.1

C-365-A

c-365-.1

c-365-.3

7-19

REPLACEABLEPARTS

Table 7-3. Analog Board, Parts List (Cont.)

circuit Keithley

Desig. DfStipti0ll Part No.

c52 Capacitor, lOOpF, lOGOV, Ceramic @SC c&4-loop

c53 Capacitor, 68pF, 5OOV, Polystyrene C-138-68~

CL54 Capacitor, 15pF, lOOV, Ceramic C-372-15~

c56~ t-a-47p

c57 c-64-22p

CRl-CR5 Diode, Silicon, lN4148 RF-28

GE Diode, Bridge Rectifier, I%05 RF-48

Diode, Silicon, MR501 m-34

CR&CR11 Diode, Silicon, Diffused, lN4149 RF-60

CR12 Diode, Silicon, lN4148 RI-28

Fl Not Used

F2 Fuse, 3A, UOV, Normal-B10 FU-82

117 Connector, Male, 6-Pin C5288-8

Kl-IO Relay RL-99

K?rK5 Relay RL-70

LI Not Used

L2-L.3 Choke TR-245

g Transistor, Ql, Q4, R7, R8 and R57 are a matched set, SSD 196-602

Not Used

z Transistor, N-Channel EET, l’N4392, SSD 31841

Transistor (see Ql) -

:cF Transistor, N-Channel FET, PN4392, SSD 31841

Not Used

Qll-Ql3 Transistor, N-Channel ET, PN4392, SSD 31841

Q14-Ql5 Not Used

Transistor, N-Channel FET, PN4392, SSD 31841

Transistor, NPN, Silicon, 2N3904 TG-47

7-20

REPLACEABLE PARTS

Table 7-3. Analog Board, Parts List (Cont.)

clrcui

Desig.

420

Q21

424

:Fi

gli

429

430

431

432

Q33

:.z.t

439

RX.?

R14

Rl5

RI6

Rl7

la8

Rl9

R20

R21

R22

R25

R26

~,., _.,,, I, AL.; ,,,__

Not Used

;oWo~ NPN, Silicon, GES5818

Not Used

l$s~s~~ N-Channel FET, BLJZYI, SSD

Transistor, N-Channel FET, BUZ7l, SSD

Transistor, MOS Power N-Channel FET, 2N7000, SSD

Transistor, N-Channel JFET, PF5301, SSD

Transistor, N-Channel m PF5301, SSD

Transistor, N-Channel FET, PN4392, SSD

Transistor, N-Channel En: PN4392, SSD

Transistor, N-Channel FET, PN4392, SSD

Transistor, MOS Power N-Channel FET, 2N7000, SSD

Transistor, N-Channel FET, BUZ;I, SSD

Transistor, N-Channel FET, BUZ7l, SSD

Transistor, MOSFET Power, PA75N85ST, SSD

Tmnsistor, MOSFET Power, PA75N85sT, SSD

Transistor, MP842, SSD

Resistor, lMtI, lo%, j/4W, Composition

Resistor, lM& lo%, XW, COnipOsition

Resistor, lkfl, 5%, VaW, Composition

Resistor, 820, 5%, YrW, Composition

Not Used

Resistor, 142.8kn, O.l%, ‘IsW, Fixed

Resistor, (see Ql)

Resistor, Thick Fii

Resistor, Thick Film

Not Used

Resistor, lOOkn, l%, lW, Metal Film

Resistor, lOOk& l%, lW, Metal Film

Resistor, lOOkiI, l%, lW, Metal Film

Resistor, lOOk& l%, lW, Metal Film

Resistor, 5600, 10%, YrW, Composition

Resistor, Thick Film

Resistor, KKJW, l%, ‘IBW, CdmpositiOn

Not Used

Resistor, 3Okbl, l%, ‘lzdW

Resistor, l3ktI, O.l%, ‘/,,W, Metal Film

Resistor, lM& l%, ‘/.W, Composition

Resistor, 2kfl, 146, ‘/,W

Resistor, l.O02kt?, O.l%, ‘IzbW, Metal Film

Resistor, Thick Film .-.. ~~~._.~~~ ~~~.~.~~~~

:.-n~ ,~

KeithIey

Pat No.

TG-I38

580-601

580&Y

TG-195

193603

TG-139

3l84l

193-603

31841

193-603

TG195

580-601

580601

SKI-601

580-601

TG175

R-76-IM

R-76-m

R-76-lk

R-76-82

R-176-142.8k

TE39

Tl-211

R-344-1OOk

R-344~1OOk

R-344~lOOk

R-344XlOk

R-76-560

TF-214

Txw%3

TJ&l%3

Tlw7x3

R-88-IOOk

R-348-30k

R-263~l3k

R-88-IM

R-?&K&

R-263-1.002k

TF-168-l

7-21

REPLACEABLEPARTS

Table 7-3. Analog Board, Parts List (Cont.)

Circuit Keithley

Desig. Description Part No.

R29~~~ Resistor, 0.8984 O.l%, SW, Wire Wound R-310-.898

R30 Resistor, 0.161, O.l%, %5W, Wire Wound R-262-A

R31 Resistoz 22M0, lo%, %W, Composiiton R-l-22M

R32 Resistor, ll8kn, O.l%, ‘I,W, Metal Film R-168-118k

R33 Resistor, l.E’M~, 0.2596, 3/W, Metal Film R-352.1.17M

R34 Resistor, ZOkn, 5%, Wiie Wound R-336-20k

R35~ Resistor, 9.09kfI, O.l%, ‘I,,W, Metal Fii R-263-9.09k

E Resistor, R36 and R37 are a matched set R-293

Resistor, R36 and R37 are a matched set R-293

zi Resistor, Thick Film TF-213

Resistor, l3k0, O.l%, ‘isW, Fiied R-l76-l3k

R40 Resistor, L3khl, O.l%, ‘isW, Fixed R-176~l3k

R41 Resistor, R41 and R42 are a matched set R-292

Ei Resistor, R41 and R42 are a matched set R-292

Resistor, XX& 5%,~ ~XW, Composition R-76-10

R44 Resistor, 104 5%, XW, Composition R-76-10

R45 Resistor, lMa, lo%, l/aW, CornpOsition R-76~lM

R46 Resistor, lM0, lo%, XW, Composition R-76-IM

R47 Resistor, lM& lo%, %W, Composition R-76~lM

R48 Resistor, lM6t, lo%, VaW, Composition R-76-lM

R49 Resistor, lMn, lo%, Yaw, Composition R-76-w

g Resistor, l.M!?, lo%, %W, Composition R-76-lM

Resistor, lMbl, lo%, Yaw, Composition R-76-m

E: Resistor, lMf& 1096, ‘/rW, Composition R-76-lM

Resistor, 470& 5%, XW, Composition R-76-470

R54 Resistor, 32&o, l%, ‘/,W, Composition R-88-32&

R55 Resistor, 2Ok0, O.l%, ‘/,,W, Metal Film R-263-20k

E; Resistor, 2Ok0, O.l%, ‘/,OW, Metal Film R-263-20k

Resistor, (see Ql)

R58 Resistor, l5.8k0, l%, ‘I,W, Composition R-88-l5.8k

R59 Resistor, 7.78k0, l%, ‘/,W, Composition R-88-7.87k

R60 Resistor, 5604 5%, XW, Composition R-76-560k

R61 Resistor, l8.2kn, I%, ‘/,W, Composition R-88-lK2k

i-2: Resistor, 8.25k3, 1%, .‘/,W, Comptisition R-88-8.25k

Resistor, 14k0, l%, ‘I&W, Composition R-88-1&

R64 Resistor, lDk$?, l%, V,W, Composition R-88-1Ok

RTl Thermister, PTC, 12200, l5.5mA RT-9-2 ~~~

Sl Switch, Pushbutton SW-468

TPl Test Point cs-553

TP2 Test Point cs-553

GE Test~Point cs-553

Test Point CS-553

Ul Not Used

E IC, squad Comparator, LM339 IC-219

IC, Quad Comparator, LM339 IC-219

u4 IC, Quad Comparator, LM339 IC-219

UC IC, Quad Comparator, LM339 IC-219

7-22

REPLACEABLE PARTS

Table 7-3. Analog Board, Parts List (Cont.)

us?

:ii

u21

K.~

U24

u28

U29

u30

u31

U32

LJ33

LJ34

LJ35

LJ36

LJ37

U38

u39

L&o

u41

u42

LJ43

LJ44

t Dewiption

I IC, Quad Z-Input NAND Gate, 74LCOO;~SSD

IC, Dual D Flip-Flop, 74HC74, SSD

1’2, Dual D Flip-Flop, 74HC74, SSD

Not Used

IC, General Purpose Op Amp, MP5502, SSD

IC, Geti&tl Pumose 00 Arm MP5502. SSD

IC, Genkral Purpose Op Am;, MP5502; SSD

Not Used

IC, Triple Z-Channel Analog Multiplexer, Selected, SSD

IC Dtial &Bit Decade Counter. 74Hc390. SSD

IC; Dual 4-Bit Counter, 74Hb93

IC, Inverting High Speed Op Amp, ME5Ol, SSD

IC, Dual Lav Power JFET Op Amp, Selected, SSD

IC, Quad Monolithic SPST CMOS &+og Switch, DG211,

IC, Quad Monolithic SPST CMOS Analog Switch, DGZll,

IC, Quad Monolithic SPST C&IOS Analog Switch, DG211,

IC, Quad Monolithic SPST CMOS Analog Switch, DG211,

IC, Wide Bandwidth JFET Input Op Amp, LF353

IC, TRMS-to-DC Converter, AD637, SSD

IC, Dual JFET Input Op Amp, LF4l2, SSD

IC, 8-Stage Shift-Store Register, 4094, SSD

IC, 8-Stage Shift-Store Register,~~4094, SSD

IC, Darlington Transistor Array, 2003, SSD

IC, Precision Reference, Selected

IC, Linear Op Amp, LM308A

IC, Wide Bandwidth JFET Input Op Amp, LP35lN

IC, Wide Bandwidth JFET Input Op Amp, Selected

Not Used

IC, Quad Comparator, LM339 ~~I alms

IC, Quad Z-Input NOR Gate, 74HcO2, SSD

IC, Triple Z-Channel Analog Multiplexer, 4053, SSD

IC, Triple 2-Charmel Analog Multiplexer, 4053, SSD

SSD

IC-351

IC-337

K-337

IC-413

K-433

IC-413

3l84%1

1C-500

x-462

IS-414

196601

1 IC-320

K-320

K-246

E-352

IC-504

IC-251

IC-206

l96-600

IC-203

IC-376

30477

IC-219

IC-412

IC-283

VRl Regulator, Zener Diode, 4.3V, lN749A

ix2 Regulator, Diode, lN702A --__

rR3 Regulator, Zener Diode, 6.3V, lN4577 DZ-58

JR4 Regulator, Zener Diode, 6.3V, lN4577 DiX8

MI Jumper J-3

n crystal, 3.84MHz CR-13

7-23

REPLACEABLE PARTS

.^ ,^

Figure 7-5. Analog Board, Component Location Drawing, Dwg. No. 196-120

7-24

I , ,

/ ! , I

_ AAAA

I-

A Cl m , a

I -

SC--

REPLACEABLE PARTS

;

Table 7-4. Model 196 Miscellaneous Parts List

Description

3ottom Cover Assembly

Bottom Cover

Shield

Tilt Bail

Dress Panel for Tilt Bail

Drive Pi for Tilt~Bail

Foot

Tou Cover Assemblv

-iOP~ Cover ’ 30540

Shield 617-322

?ront Panel Assembly

Front Panel

Display Window

Front Panel Overlay

Banana Jack, Black

Banana Jack, Red

Banana Jack, White

Pushbutton, Light Brown

Pushbutton, Brown

Pushbutton, Red

7e.w Panel Assembly

Rear Panel

Ground Clip

BNC Connector

Bananas Jack, Black

Banana Jack, Red

Banana Jack, White

Pushbutton, Red

Line Cord

Xrcuit Board Assemblies

Analog Board Shield

Analog Board Mounting Plate

Spacer (Supports Plate of Mother Board)

Keithley

Part No.

617-318

617-321

30544

30587

FA-143-l

FE-14

196-302

196-303

196-312

BJ-12-O

BJ-12-2

BJ-12-9

228-317-5

228-317-6

29465-3

196-308

775-306

CS-520

BJ-12-O

BJ-X2-2

BJ-12-9

29465-3

co-7

196-306

196-304

31843-l

7-an-34

APPENDIX A

ASCII CHARACTER CODES AND IEEE-488 MULTILINE INTERFACE COMMAND MESSAGES

Decimal Hexadecimal ASCII IEEE-488 Messages*

0 00

1 01

2 02

3 4 ifi

6 z:

7 07

; 08

10 OA

11 OB

iii oc

ii OE

16 10

17 11

18 12

19 13

20 14

21 15

22 16

23 17

24 18

26 18

29 1D

30 lE

NUL

SQH~~ GTL

EOT SDC

~PPC

H-r

DLE

DC1

DC2

DC3

DC4

~NAK

SYN

ETB

CAN

SUB

ESC

GET

TCT

LX0

DCL

IWJ

X=‘E

SPD

31 IF USA .i~.

* Message sent or received with ATN true.

A-l

APPEND\X A

ASCII CHARACTER CODES AND IEEE-488 MULTILINE INTERFACE COMMAND MESSAGES

Decimal Hexadecimal ASCII IEEE488 Messages*

32 20

34 z

35 23

36 24

39 27

4.0 28

ii 29

43 28

44 2c

E 2D

47 2F

48 30

49 31

50 32

51 33

Ei 34

55 :;

MLAO

.MLAl

ML‘52

MLA 3

MLA4

MLA 5~

MLA6

MLA 7

MLA 8

MLA9

MLA 10

MLA 11

MLAl2

MLA 13

~MiA 14

MLA 15

MLA 16

MLA 17

MLA 18

MLA 19

MLA 20

MLA 21

MLA 22

MLAW

56 38

57 39

59 2

60 3c

61 3D a

62 3E >

63 3F ? UNL

MLA~24

MLA 25

ML.4 26

MLA2.7

MLA 28

MLA 29

~MLA 30

* Message sent or received with KIN true.~Numbers shown represent primary address resulting

in ML4 (My Listen Address).

A-2

APPENDIX A

ASCII CHARACTER CODES AND IEEE-488 MULTILINE INTERFACE COMMAND MESSAGES

Decimal Hexadecimal ASCII IEEE=488 Messages*

4.4

x MT.4 24

MTA6

Es’

MTA9

MTA 10

ilK%i

MTAl3

MT.4 14

ml5

MIX 16

MTN.7

MT.418

MT.4 19

MTA 20

Mm 21

tEz

MT.427

MTA 28

MT4 29

MT4 30

95 5F UNT

* Message sent or received with ATN true. Numbers shown are primary address resulting in MTA

(My Xlk Address).

A-3

APPENDIX A

ASCII CHARACTER CODES AND IEEE-488 MULTILINE INTERFACE COMMAND MESSAGES

Decimal Hexadecimal ASCII IEEE-488 Messages*

96 60

ii: 65

102 66

103 67

lo4 68

E 69 ~” -~

107 68

lO8 6C

lo9 6D

110 6E

111 6F

ll.2 70

~72

115 73

116 74

ll.7 75

1X3 76

119 77

MSA 0,PPE

MSA 1,l’l’E

MSA 2,PPE

MSA 3;PpE

MSA 4,PPE

MSA 5,PPE

MSA 6,IT’E

MSA 7,l’l’E

MSA S,PPE-

MSA 9,PPE

MSA 10,l’l’E

MSA 11,PPE

MSA l2,l’PE

MSA l3;PPE

MSA 14,l’PE :

MSA l5,I’PE

MSA l6,PPD

MSA lX’I?D

MSA 18,l’l’D

MSA 19,PPD

MSA 20,Pl’D

MSA 21.l’PD

MS?% 22,iTD

MSA 23,ppD

MSA 24J’PD

MSA 25,PrD

MSAi6,PPD

MSA 27,PPD

124 7c MSA 28,PPD

125 7D MSA 29,PPD

126 7E MSA 30,I’l’D

127 7F IJEL

*Message send or received with ATN hue. Numbers represent secondary address values resulting

in MSA (My Secondary Address).

A-4

APPENDIX 6

IBM PC/XT and MODEL 8573A PROGRAMMING

INTRODUCTION SOFTWARE CONFIGURATION

This appendix contains general programming information Before~using the Model 8573A, you mustconfigure the soft-

needed to control the Model 196 using the IBM PUG per- ware by using the procedure below. Note that the binary

sonal computer via the Keithley Model 8573A IEEE-488 in- handler fde called Gl’lB.COM and the system ~onfigura-

terface. Refer to the Model 8573A Instruction Manual for tion file called CONFIG.SYS must be present on the DOS

complete programming information; booty disk, as described in the Model 8573A Instruction

Mamlal.

CONTROLLER HANDLER SOFTWARE 1. Boot up your system in the usual manner and enter

BASICA. ~~~

Before a specific tiontroller can be used over the IEEE-488

bus, it must have the appropriate IEEE-488~handler soft-

ware installed. For the IBM computer, the necessary

handler software is provided on diskette, along with the

Model 85734 interface.

INTERFACE BASIC PROGRAMMING

STATEMENTS

This section covers the Model 8573A statements that are

essential to Model 196 operation. A partial list of program-

ming statements are listed in Table B-l. Each of these

statements uses the IBM BASIC CALL statement, with

various variables as shown in the table. The command

words such as IBCLR (Interface Bus Clear) and IBSRE (In-

terface Bus Send Remote Enable), are in fact BASIC

variables themselves, which must be initialized at the start

of each BASIC program.

2; Place the Model 8573A software disk into~ the default

drive and load the program called “DECL. BAS’! Modify

the program by changing the XXXXX values in lines 1

and 2 to l6Ci30.

3. Add the fojlowing lines to the declaration file:

: #*EL i Gp~IBMI 5~ : CALL IEFIN~IN178~,~XHDU%j

8 t.tcI$=L ‘DEW3 ’ CALL IXFI~HD~NW~Mi96%:~

9 II%=7:mLL IEPfmItli96%rU:+~>

4. Now save the modified declaration file for future use.

Remember that you must load and nm this short pro-

gram before programming the Model 196 over the bus.

Also; do not use the BASIC~CLEAR or NEW command

after running this program.

Note: An example program using the IBM PC/XT and the

Model 8573A can be found in Appendix C.

Table B-l. BASIC Statements Necessary to Send Bus Commands

ActlOll

Transmit string to device Z

Obtain string from device Z

Send GTL to device Z

Send SDC to device 7.

Send DCL to all devices.

Send remote enable.

Cancel remote enable.

Serial poll device 7.

Send Local Lockout.

Send GET to device.

Send LFC.

Model 8573A &+ame+

CALL IBl.tRT ‘:Eii%::r CMDBI~

B-IIB-2

APPENDIX C

CONTROLLER PROGRAMS

The following programs have been supplied as a simple aid to the user and are not intended to

suit specific needs. Each progrm~allows you to send a device-dependent command string to the

instrument and obtain and display an instrument reading string.

Programs for the following controllers are iqcluded:

l IBM PC or XT (with Keithley Model 8573A IEEE-488 Interface)

l Apple II (equipped with the Apple II IEEE-488 Interface)

l Hewlett-Packard Model 85

l Hewlett-Packard Model 9816

l HewlettJ’ackxd Model 9825A

. DEC LSI 11

. l’ET/CBM 2001

APPENDIX C

IBM PC OR XT (KEITHLEY MODEL 8573A INTERFACE)

The following program sends a command string to the Model 196 from an IBM PC or XT corn-

puter and displays the instrument reading string on the CRT. The computer must be equipped

with the Keithley Model 8573A IEEE-488 Int&ace and the DOS 2.00 oper+ing system. Model 8573A

software must be installed and configured as described in the instruction manual.

DIRECTIONS

1. Using the front panel program feature, set the primary address of the Model 196 to 7.

2. With the power off, connea~the Model 196 to the IEEE-488 interface installed in the IBM

computer.

3. Type in BASICA on the computer keyboard to get into the IBM interpretive BASICS language.

4. Place the interface software disc in the default drive, type LOAD”DECI?, and press the return key.

5. Add the lines below to lines l-6 which are now in memory. Modify the address in lines 1 and

2, as descried in the Model 8573A Instruction Manual.

6. Run the program and typein the desired~~command sting. For example, to place the instru-

ment in the ACV function and autoiawe, tvue in FlROX and press the return kev.

I. I_

7. The instrument reading string will then appear on the display. l&r example, the display might

show NDCV+O.OOOOO(IE+O.

8. To exit the program, type in EXIT at the command prompt and press the return key.

PROGRAM CwMENTs

Clear screen.

Find board descriptor.

Find instrument descriptor.

Set primary address to 7.

Set timeouts.

Set REN true.

Prompt for command.

Se& if program is to be halted.

check for null input.

YAddress 196~ to listen, send string.

Defme reading input buffer.

Address 196 to talk, get reading.

Display the string.

Repeat.

Close the instrument file.

Close the board file.

NOTE: For conversion to numeric variable, make the following changes:

130 RD=VHL,~tlIDBiRDB~5~ 14jj

135PRINTRD

APPENDIX C

APPLE II (APPLE II IEEE-488 INTERFACE)

The following program sends a command string to the Model 196 from an Apple II computer

and displays the instrument reading string on the computer CRT.

The computer must be equipped with the Apple II IEEE-488 Interface installed in slot 3.

DIRECTIONS

1. Using the front panel program feature, set the primary address of the Model 196 to 7.

2. With the po-wer off, connect the Model 196 to the IEEE-488 interface installed in the Apple II

computer.

3. Enter then lines in the program below, using the RETURN key after each line.

4. Run the program and typein the desired cotimand string at the command prompt. For exam-

ple, to place the instrument in ACV and autorange; ~tipe in FlROX and press the return key.

5. The instrument reading string will then appear on the CRT A typical display is:

NDCV+O.OOOOOOE+O.

PROGRAM COMMENTS

Terminator.

Prompt for and enter command string.

Set output to IEEE488 bus.

4E1 It4#3 ~Define hput froti~ IEEE-488 bus.

50 PI?1 NT r L RA’ ’ Enable remote.

60 PRINT ‘ r MT7 ’ I i ZB.; ES: Address 196 to listen, send string. map

7@FRINT rrLFi” Line feed on.

~~F’RIt~T~~RDG’~;2$j:It~FCITrr “illlBm Address 196 to talk, input data.

90 PRINT <<UT” Untalk the 196.

100 PR#O Defiie~output to CRT.

ii9 IH#U Defines input from keyboard.

120 PRINT f%- Display reading string.

130 GUTl2Ei Repeat.

NOTES:

1. If conversion to numeric variable iS required, make the following changes:

2. The Apple II terminates on commas in the data string. To avoid problems, program the Model

196 for the BOG0 or BOG1 data format to eliminate commas.

c-3

HEWLETFPACKARD MODEL 85

The following program sends a command string to the Model 196 from an HP-85 computer and

displays the instrument reading string on the computer CRT. The computer must be equipped

with the HP82937 GPIB Interface and an I/O ROM.

DIRECTIONS

1. Using the front panel program feature, set the primary address of the Model 196 to Z

2. with the power off, connect the Model 796 to the HP82937A GPIB interface installed in the HP85

computer.

3. Enter the lines in the program below, using the END LINE key after each line.

4. Press the HP-85 RUN key and type in the desired command string at the command prompt.

For example, to place the instrument in ACV and autorange, type in FlROX and press the END

LINE kev.

5. The instrument reading string wi!.l then appear on the CW. A typical display is:

NDCV+O.OOOoOOE+O.

PROGRAM COMMENTS

10 DIM WL251, BBC251

20 REMOTE 707

30DISPL’COMMCINDSTRIt~G~‘j

Dimension strings.

Place 196 in remote.

Promot for command.

40 IWUT A8

50 OUTPUT 707; A5 Input’command shing.

C0 ENTER 707; B9 Address 196 to listen, send string.

70 DISP BO: Address I.96 to talk, input reading.

~Display reading string.

80 GOTU 30

90 END Repeat

NOTE: For conversion to numeric variable, change line 70 as follows:

c-4

APPENDIX C

HEWLETT-PACKARD MODEL 9818

The following p~ogrm sends a command string to the Model 196 from a Hewlett-Packard Model

9816 computer and displays the instrument readiig string on the computer CRT. The computer

must be equipped with the HP82937 GPlB Interface and BASIC 2.0.

DIRECTIONS

1. Using the front panel program feature, set the primary address of the Model 196 to Z

2. With the power off, connect the Model 196 to the HP82937A GPIB interface installed in the 9816

computer.

3. Type EDIT and press the EXEC key.

4. Enter the lines in the program below, using the ENTER key after each line.

5. Press the 9816 RUN key and type in the desired command string &the command prompt. For

example, to place the instrument in ACV and autorange, type in FlROX and press the ENTER key.

6. The inshument reading string will then appear on the CRT. A typical display is:

NDCV+O.OOOOOOE+O.

PROGRAM COMMENTS

10 REMOTE707 Place 196 in remote.

15 DIM A5[251r E5E25~1

201NPUTLrCOMNANIISTRING”rA5:

30 OUTPUT 707; A5

40ENTER707i BB

50 PRINT E$

60 GOT0 20

70 END

Prompt for and input command.

Address 196 to listen, send string.

Address 196 to talk, input reading.

Display reading string.

Repeat.

NCYE: For conversion to a numeric variable, change the program as follows:

40ENTER707;E

50 PRINT~F

c-5

APPENDIX C

HEWLETT-PACKARD MODEL 9825A

Use the following program to send a conirixand string to-the Model 196 from a Hewlett-Packard

Model 9825A and display the instrument reading string on the computer printer. The computer

must be equipped with the HP98034A HPlB Interface and a 98724 extended I/O ROM.

1. Fr%%ri the front panel, set the primary address of the Model 196 to 7.

2. With the power off, connect the Model 196 to the 98034A HPlB interface installed in the 9825A.

3. Enter the lines in the program below, using the STORE key after each line. Line numbers are

automatically assigned by the 9825A.

4. Press the 9825A RUN key and typein the desired command string at the command prompt.

For example, to place the instrument~in ACV and autorange, type in FlROX and press the CONT

key.

5. The instrument reading string will then~appear on the computer print out. A typical display

is: NDCV+O.OOOOOOE+O.

PROGRAM COMMENTS

Dimension data strings.

~Defiie 196 at address 7.

Place 196 in remote.

Prompt for command string.

Address 196 to listen, send string.

Address 196 to talk, input data.

Print data string on printer.

Repeat.

NOTE: For conversion to numeric Variable, modify the program as follows:

6 prt valIABC51)

C-8

APPENDIX C

DEC LSI 11

The following program sgnds a command string to the Model 196 from a DEC LSI ll minicom-

puter and displays the instrument reading string on the DEC CRT~t$nnin& The LSI 11 must be

configured with l6K words of RAM and an IBV 11 IEEE-488 interface. The software must~be con-

figured with the IB software as welI as FORTRAN and the RT 11 operating system.

DIRECTIONS

1. Using the front panel program feature, set the primary address of the Model 196 to 7.

2. With the power off, connect the Model 196 to the IBV 11 IEEE-488 interface cable.

3. Enter the program below, using the editor under RT 11 and the name IEEEFOR.

4. Compile using the FORTRAN compiler as folIows: FORTRAN IEEE.

5. Link with the system and IB libraries as follows: LINK IEEE,IBLIB.

6. Type RUN IEEE and press the RETURN key.

Z The display will read “ENTER ADDRESS”.

8. Type in 7 and press the RETURN key.

9. The display wiIl read “TEST SETUP’:

10. Type in the desired command string and press the RETURN key. For example, to program

the instrument for ACV and autorange, type in FlROX and press REZTURN.

11. The instrument data string will appear on the computer display. A typical display is:

NDCV+O.OOOOOOE+O.

PROGRAM

CkLL IESTER’I,B>

2 CONTINUE

CRLL IBSTER115rS:n

WLL IBTIM~O~:120~

CALLIETERM<lO>

CtiLL IRREN

4 T’iPE 5

5 FORWT < 1X, r ENTER ADDRESS : ’ 3 BZ’

ACCEPT 10sPRIADR

10 FURMAT <12:)

12 TYPE 15

i5FORMATr.iX~LTE!~TSETUP:‘~5:~

CALL GETSTR (53 NSG, 72)

CALL IESEOI IMfG, -1sPRIADHj

1E: I=IEREC!J (INPCIT, 80, PRIADR:l

INPCIT II+13 =0

CALL PIJTSTR 177 INPUT, 80’ >

CQLL IBUNT

GOT0 12

END

- COMMENTS

Turn off IB etiors.

Allow 5 error 15’s.

Allow 1 second bus timeout.

Set line feed as terminator.

Turn Ofi remote.

Input primary address.

Prompt for command string.

Frogran instruments

Address 196 to listen, send string.

Get data from instrument.

Untalk the 196.

Repeat.

PETICBM 2001

The following program sends a co mmand string to the Model 196~ from a l%T/CBM 2001 com-

puter and displays the instrument reading string on the computer CRT. As the PB UCBM corn-

puter has a standard IEEE-488 interface, no additional equipment is necessary.

DIRECTIONS

1. Using the front panel program feature, set the primary address of the Model 196 to Z

2. With the power off, connect the Model 196 to the PETlCBM IEEE-488 interface.

3. Enter the lines of the program below, using the RETURN key after each line is typed.

4. TypeRUN and press the RETURN key. Type in the desired command string at the command

prompt. For erample, to place the instrument in ACV and autorange, types in FlROX and press

the RETURN key.

5. The instrument reading string will then appear on the CRT. A typical display is:

NDCV+O.OOOOOOE+O.

PROGRAM COMMENTS

18OPEN ir7

20 INPUT’ r CCMliWD STRING’ F ;EB

30 PRINT#lrE$

40 INPLlT#i I A$

59 IF ST=2 THEN 40

60 PRINT A$

70 GOTO 20

NOES:

Open file 1, primary address Z

Prompt for, input command string.

Address 196 to listen, send string.

Address 196 to talk, input data.

If bus timeout, input~~~again.

Epldl reading string.

1. If conversion to numeric variable is required, modify the program as follows:

2. The PET terminates on commas in the data string. To avoid problems, program the Model 196

for the BOG0 or BOG1 data format to eliminate commas.

APPENDIX D

IEEE-488 BUS OVERVIEW

BUS DESCRIPTION

The IEEE-488 bus, yhich is also frequently referred to as

the GPIB (General Purpose Interface Bus), was designed

as a parallel transfer medium to optimize data transfer with

a minimum number of bus lines. In keeping with this goal,

the bus has eight data lines that are used both for data and

many commands. Additionally, the bus has~five manage-

ment lines, which are used to control bus operation, and

three handshake lines that are used to control the data byte

transfer sequence.

A typical configuration for controlled bus op&tion is

shown in Figure D-l. A typical system will have one con-

troller and one or more devices to which commands are

given and, in most cases, from which data is received.

Generally, there are three categories that describe device

operation: controller, talker, and listener.

The controller does what its name implies: it con&cJ.s other

devices on the bus. A talker sends data (usually to the con-

troller), and a listener receives data. Depending on the in-

strument, a particular device may be a talker only, a listener

only, or both a talker and a listener. The Model 196 has

both talker and listener capabilities.

There are two categories of controllers: system c+rolIer

and basic controller. Both are able to control other devices,

but only the system controller has absolute authority in

the system. In a system with more than ones co&r&r, only

one controller may be active at any given time. Certain

command protocol allows control to be pa&d from OS

controller to another.

The bus is limited to I5 devices, including the controller.

Thus, any number of devices may be present on the bus

at one time. Although several active listeners may be pre-

sent simultaneously, only one act& t$kFr may be present

on the bus, or communications would be scrambled.

TO OTHER DEVICES

, \

MANAGEMENT

Figure D-l. IEEE Bus Configuration

D-1

A device is placed in the talk or listen mode from the con-

troller by sending an appropriatetalk or listen command.

These talk and listen commands are derived from an in-

strument’s primary address. The primary address may

have any value between 0 and 30 and is generally set bye

rear panel switches or programmed in from the front ~pairel

(as in the case of the Model 196). The actual listen com-

mand value sent over the bus is derived by ORing the

primary address with $20 (the $ symbol preceding the

number designates a hexadecimal, or base 16 value). For

example, if the primary address is 7 (the default Model

196 value), the actual listen command byte value is $27 ($07

+ 520 = $27). In a similar manner, the talk command byte

is derived by ORing the primary address with 540. With

a priniaty address of 7, the actual talk command byte

would be 547 (540 + 507 = 547).

The IEEE-438 standards also include another addressing

mode called secondary addressing. Secondary address

byte values lie in the range of $60-$7F. Note, however, that

many devices, including the Model 196, do not use secon-

dary addressing.

Once the device is properly addressed, bus transmission

sequences are set to take place. For example, if an instru-

ment is addressed to talk, it will usually outputs its-data

string on the bus one byte at a~ time. The listening device

(frequently the controller) will then read this information

as transmitted.

BUS LINES

The signal lines on the IEEE488 bus are grouped into three

categories: data lines, management lines, and handshake

lines. The eight data lines handle bus data and many com-

mands, while the management and handshake lines en-

sure orderly bus operation. Each bus line is active low with

approximately zero volts representing logic 1 (true). The

following paragraphs briefly describe the operation of

these lines.

Data Lines

The bus uses eight data lines tom transmit and receive ~data

in bit-parallel, byte serial fashion. These lines use the con-

vention DIOI-DI08 instead of the more common DO-D7

DIOl is the least significant bit, while D108 is the most

significant bit. The data lines are bidirectional (with most

devices), and, as with the remaining bus lines, low is con-

sidered to be true.

Bus Management Lines

The five bus management limes ensure proper interface

control and management. These lines are used to send

uniline commands.

ATN (Attention)-The state of ATN determines how infor-

mation on the data lines is to be interpreted.

IK (Interface Clear)-lFC allow the clearing of active

talkers or listeners from the bus.

REN (Remote Enable)-REN is used to places devices in

the remote mode; Usually, devices must be in remote

before they can be programmed over the bus.

EOI (End Or Identify)-EOI is used to mark the end of

a multi-byte data transfer sequence. EOI is also used along

with !XN, to send the IDY (identify) message for parallel

polling.

SRQ (Service RequestGSRQ is used by devices to request

service from the controller.

Handshake Lines

Three handshake lines that operate in an interlocked se-

quence are used to ensure reliable data transmission

regardless of the transfer rate. GeneraLly, data transfer will

occur at a rate determined by the slowest active device on

the bus. These handshake lines are:

DAV (Data ValidPThe source (talker) controls the state

of DAV to indicate to any listeners when ~data is valid.

NRFD Orot Ready For Data)-The acceptor (listener) con-

trols the state of NRFD. It is used to signal the transmit-

ting device to hold off the byte transfer sequence until the

accepting device is ready.

NDAC (Not Data Accepted)-NDAC is also controlled by

the accepting device. The state of NDAC tells the source

whether or not the device has accepted the data byte.

Figure D-2 shows the basic handshake sequence for the

transmission of one data byte. This sequence is used to

transfer data, talk and listen addresses, as well as multiline

commands.

D-2

APPENDIX D

DATA SOURCE

I I

NDAC I ACCEPTOR

OA’TA DATA

TRANSFER TRANSFER

BEGINS ENDS

Figure D-2. IEEE Handshake Sequence

BUS COMMANDS

Cdtimands associated with the IEEE-488 bus can be

grouped into~ the following three general categ@s. Refer

to Table D-l.

UniIine Commands--These commands are %serted by set-

ting the associated bus line true. For example, to assert

REN (Remote Enable), the REN line would be~set low

(true).

Multiline Commands-General bus commands which are

sent over the data lines with the Al’N line true.

Device-dependent Commands-Comman ds whose mean-

ings depend on the device in question. These commands

are transmitted via the data lies while ATN is false.

Table D-l. IEEE-488 Bus Command Summary

State of

Command Type Command ATN Line* Comments

Unilille REN (Remote Enable) X Sets up devices for remote operation.

EOI X Marks end of transmission.

IFC (Interface a4 X clears Interface.

ATN (Attention) Low Defines data bus contents.

SRQ X Controlled by external device.

Multiline

UlliVersal LLQ (Local Lockout) Low Locks out local operation.

DCL (Device Clear) Law Returns device to default conditions.

SPE (Serial Enable) Law Enables serial polling.

SPD Serial PoII Disable) Low Disables serial polliig.

Addressed SDC (selective Device Clear) Low Returns unit to default conditions.

GTL (Go To Local) Low Returns device to local.

GET (Group Execute Trigger) Low Triggers device for rea$ing.

Unaddressed UNL (Unlisten) Low Removes all listeners from bus.

IJNT (Untalk) Low Removes any talkers from bus.

Device-dependent High Programs Model 196 for tious modes.

*Don’t Care.

D-3

Uniline Commands

The five uniline commands include REN, EOI, lFC, Al’N,

and SRQ. Each comman d is associated with a dedicated

bus lie, which is set low to assert the command in

question.

REN (Remote Enable&EN is asserted by the controller

to set up instruments on the bus for remote operation.

When REN is true, devices will be removed from the local

mode. Depending on device configuration, ail front panel

controls except the LOCAL button (if the device is so

equipped) may be locked out when REN is true. General-

ly REN should be asserted before attempting to program

instruments over fhe bus.

EOI (End or Identify)-EOI may be asserted either by the

controller or by external devices to identify the last byte,

in a multi-byte transfer sequence, allowing data words of

various lengths to be transmitted.

IFC (Interface Clear)-IFC is asserted by the controller to

clear the interface and return all devices to the talker and

listener idle states.

ATN (Attention)-The controller asserts KIN while sen-

ding addresses or multiline commands.

SRQ (Service Request)-SRQ is asserted by a device on

the bus when it requires service from the controller.~

Universal Multiline Commands

Universal multiline commands are those uxnmands that

required no addressing as part of the command sequence.

Ail devices equipped to implement these commands will

do so simultaneously when the commands are transmit-

ted. As with all multiline commands, these commands are

transmitted with ATN true.

LI.0 (LncaI Lockout)-LLO is Sent to instruments to lock

out front panel or local operation of the instrument.

DCL (Device Clear)-DCL is used to return instruments

to some default state. Usually, devices return to their

power-up conditions.

SPE (Serial Poll Enable)-SPE is the first step in the serial

polling sequence, which is used to determine which device

on the bus is requesting service.

SPD (Serial Poll Disable)-SPD is used by the controller

to remove all devices on the bus from the serial poll mode

and is generally the last command in the serial polling

sequence.

Addressed Multiline Commands

Addressed multiliie conunan ds are those commands that

must be preceded by an appropriate listen address before

the instrument will respond to the command in question.

Note that only the addressed device will respond to the

command. Both the command and the address preceding

it ilIe sent with .KlYJ true.

SDC (Selective Device Clear)-The SDC command per-

forma essentially fhe same function as DCL except that on-

ly the addressed device responds. Generally, instruments

return to their power-up default conditions when respon-

ding to SDC.

GTL (Go To Local)-GTL is used to remove instruments

from~the remote mode and place them in local. With many

instruments, GTL may also n?store operation of front panel

controls if previously locked out.

GET (Group Execute Trigger)-GET is used to bigger

devices to perform a specific action that will depend on

device con@uration (for ~ple, perform a measurement

sequence). Although GET is an addressed command,

many devices may respond to GET without addressing.

Address Commands

Addressed co remands include two primary command

groups, and a secondary address group. ATN is true when

these conman ds are asserted. These commands include:

LAG (Listen Address Group)-These listen commands are

derived from an instrument’s primary address and are

used to address devices to listen. The actual command byte

is obtained by ORing the primary address with $20.

TAG (TaIk Address Group)-The talk co-nds~ are de-

rived from the plimary address by ORing the address with

$40. Tdk commands are used to address devices to talk.

SCG (Secondary Command Group)-Commands in this

group provide additional addressing capabilities. Many

devices (icluding the Model 196) do not use thes~e

commands.

D-4

APPENDIX D

Unaddress Commands

The two unaddress~commands are used by the controller

to remove any talkers or listeners from the bus. ATN is true

when these commands are asserted.

UNL Wnlis&n)-Listeners are placed in the listener idle

state by UNL.

UNT @Jntalk)-Any previously commanded talkers will

be placed in the talker idle state by LINT.

Device-Dependent Commands

The purpose of device-dependent commands will depend

on instrument configuration. Generally, these commands

are sent as one or more ASCII characters that command

the device to perform a specific action. For example, the

command string ROX is used to control the measurements

mnge of the Model 196.

The IEEE-488 bus treats these commands as data in thatch

ATN is false when the commands are transmitted.

Command Codes

Command codes for the various commands that use the

data lines are s-tied in Figure D-3. Hexadecimal and

and decimal values for the various commands are listed

in Table D-2.

D-5

APPENDlX G

I I El I I I I I I I I I I I I I I I

Ix/ I ~I-I-I-I~I-I~I>I~I~I-I~I-I..I-III~

11 i i i i i i i I

Figure D-3. Command Codes

D-6

APPENDIX D

Table D-2. Hexadecimal and Decimal Command

Codes

Command

GTL

SDC

GET

LLO

DCL

SpE

SPD

Hex Value

ZO-3F

406F

60-7F

32-63

64-95

96-W

Typical Command Sequences

For the various multiline commands, a specific bus se-

quence must take place to properly send the command.

In particular, the correct listen address must be sent to the

insment before it wiJ.l respond to addressed commands.

Table D-3 lists a typical bus sequence for sending an ad-

dressed m&line command. In this instance, the SDC

command is being sent to the instrument. UNL is generally

sent as part of the sequence to ensure that no other active

listeners are present. Note that ATN is true for both the

listen command and the SDC conimand byte itself.

Table D-3. Typical Addressed Command Sequence

St&s low EOT 04 4

4 Retqw high I I

*Assumes primary address = Z

%ble D-4 gives a typical device-dependent~command se-

quence. In this instance, XI’N is true while the instrument

is being addressed, but it is set high while sending the

device-dependent command string.

Table D-4. Tvaical Device-Dependent Command

Sequence .

I I I I

Step Command ATN Stz$e ASCI

1 I UNL ISetlow I ?

IEEE Command Groups

Command groups supported by the Model 196 are listed

in Table D-5. Device-dependent commands are not includ-

ed in this list.

Table D-5. IEEE Command Group

HANDSHAKE COMMAND GROUP

DAC=DAZlX ACCEFTED

WD=READYFORD.UA

DAV=DXlA VALID

UNIVERSAL COMMAND GROUP

ATN=xKl-I’ENTION

DCL=DEVICE CLEAR

JFC=INTERFACE CLEAR

LLO=LOCAL LQCKOUT

REN=RFMOTE ENABLE

~PD=~~~ALIJOLLD~~AB~

SPE=SERIAL POLL ENABLE

ADDRESS COMMAND GROUN

LISTEN: LAG=LISTEN ADDRESS GROUP

MLA=MY LISTEN ADDRESS

UNL=UNLISTEN

TALK: TAG=TALK ADDRESS GROUP

M’C4=MY TALK ADDRESS

UNT=UNTALK

oTA=OTHER TALK ADDRESS

ADDRESSED COMMAND GROUP

ACG=ADDRESSED COMMAND GROUP

GET=GROUP EXECUTE TRIGGER

GTL=GO TO LOCALS

SDC=SELEClWE CLEAR

STATUS COMMAND GROUP

RQS=REQUEST SERVICE

SRQ=SERIAL POLL REQUEST

STB=SWS BYTE

EOI=END

D-7/D-8

Auto Auto Auto Auto AlltO AlltO AUtO Auto

300mV3CGmV3WpA3CGpA 300 II Auto AUtO Auto

3v3v3mA3m4 3kn Auto AUtO 3kll

3ov3omv3omA3amA 3okn Auto Auto 3okn

3&l v3al vmmA3mmA 300 ktl Auto Auto 3okn

Zero disabled

3Yid 3%d 3Hd 3’hd 3Md(R1-R4) 5Yzd 5Hd 5Yzd

5Md(R5-W)

41hd 4’hd 4%d 444d 4Hd(RI-R4) 5Yzd Shd 5%d

5%d(R55-R7

5%d 5Vtd 5’hd 5Yzd 5Y2d 5’hd 5Kd 5Md

6Hd 5Yxd 5Md 5Vld 6Kd@l-R6) 5Yzd 5’hd 6Yzd

ontmuous on

One-shot on Talk

Continuous on GET

One-shot on GET

Continuous on X

One-shot on X

Device-Dependent Command Summary (Cont.)

Data store full

Service Form

Model No. .Serial No.

Name atid Telephone No.

Company

List all control settings, describe problem and check boxes that apply to problem.

Date

Cl Intermittent

0 IEEE failure

a Front panel operational

Display or output (clwk one)

0 Drifts

m Unstable

0 Overi&d

0 Calibratiofi only

0 Data required

a Analog output follows display a Particular range or function bad; specify

0 Obvious problem on power-up 0 Batteries and fuses are OK~

m All ranges or functions are bad 0 Checked all cables

(attach any additional sheets as necessary)

Show a block diagram of your measurements :ystem including all instruments connected (whether power is turned on or not).

Also, describe signal source.

Where is the measurement being performed? (factory, controlled laboratory, outdfdoors, etc.)

What power line voltage is tied?~ Ambient temperature?

Relative humidity? Other?

Any additional information. (If special tiodifications have been made by the user, please describe.)

“F

Unknown KEI_196 KEI 196

Navigation menu

Versions of this User Manual:

Views

Navigation