Disclosure to Promote the Right To Information

Whereas the Parliament of India has set out to provide a practical regime of right to information for citizens to secure access to information under the control of public authorities, in order to promote transparency and accountability in the working of every public authority, and whereas the attached publication of the Bureau of Indian Standards is of particular interest to the public, particularly disadvantaged communities and those engaged in the pursuit of education and knowledge, the attached public safety standard is made available to promote the timely dissemination of this information in an accurate manner to the public.

इंटरनेट मानक

“!ान $ एक न' भारत का +नम-ण”Satyanarayan Gangaram Pitroda

“Invent a New India Using Knowledge”

“प0रा1 को छोड न' 5 तरफ”Jawaharlal Nehru

“Step Out From the Old to the New”

“जान1 का अ+धकार, जी1 का अ+धकार”Mazdoor Kisan Shakti Sangathan

“The Right to Information, The Right to Live”

“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता है”Bhartṛhari—Nītiśatakam

“Knowledge is such a treasure which cannot be stolen”

“Invent a New India Using Knowledge”

है”ह”ह

IS 1885-52-13 (1980): Electrotechnical vocabulary : Part 52- Data processing, Section 13: Analogue and hybridcomputing [LITD 14: Software and System Engineering]

IS : 1885 ( Part LII/Sec 13 ) - 1980

Indian Standard

ELECTROTECHNICAL VOCABULARY PART LII DATA PROCESSING

Section 13 Analog and Hybrid Computing

Basic Standards on Electronics and Telecommunication Sectional Committee, LTDC 1

Chairman

MAJ-GEN K. K. MEHTA ( RETD )

Representing

Chairman, Electronics and Telecommunication Division Council

Members

SHRI D. C. BHATTACHAREE Institution of Electronics and Telecommunication Engineers, New Delhi

DR V. P. KODALI ( ALternate) DR K. CHANDRA National Physical Laboratory ( CSIR), New Delhi SHRI B. A. CHEW Department of Electronics, New Delhi DIRECTOR Department of Science & Technology, New Delhi DR C. G. KHOT Railway Board, Ministry of Railways

SHRI RAVINDRANATH ( Altcrnatc ) SHRI 0. P. KHUSHU All India Radio, New Delhi GP-CAPT J. S. LAMBA Directorate of Technical Development & Production

(Air), Ministry of Defence, New Delhi SHRI R. SOMASUNDARAM ( Alternate )

SHRI M. H. V. MURTHY Ministry of Defence SHRI J. V. SASTRY Posts and Telegraphs Department, New Delhi SHRI T. V. SRIRANGAN Vice-Chairman, Electronics and Telecommunication

Division Council SHRI R. C. JAIN, Director General, IS1 ( Ex-o&o Member)

Head ( Electronics ) ( Secretary )

Computers, Business Machines and Calculators Sectional Committee, LTDC 24

Chairman

BRIG A. BALAWBRAMANIAN, AVSM Ministry of Defence ( R & D ), New Delhi

Members

SHRI K. S. ANANDA RAO Bharat Electronics Ltd, Bangalore SHRI C. K. BAPIRAJU State Bank of India, Bombay

( Continued on page 2 )

0 Copyright 1981

INDIAN STANDARDS INSTITUTION

This publication is protected under the Indian Copyright Act ( XIV of 1957 ) and

reproduction in whole or in part by any means except with written permission of the

publisher shall be deemed to be an infringement of copyright under the said Act.

IS : 1885 ( Part LXI/Sec 13 ) - 1980

( Continued from page 1 )

Members

SH~I A. K. BASAK

R@rcsmting

Development Commissioner, Small Scale Industries, New Delhi

SHRI P. P. MALHOTRA ( Ahnatc ) SHRI A. K. BINDAL Weston Electron&s Ltd, New Delhi SHRI V. M. GA~JTAM Delhi Cloth & General Mills Co Ltd, Delhi

SHRI ANUFNM GIJPTA ( Altemate ) SHRI A. C. JAIN Bharat Heavy Electricals Ltd, New Delhi SHRI ARJUN MALHOTRA Hindustan Computers Ltd, New Delhi

SHRI R. S. PAWNER ( Ahmate) SHRI S. C. MODI Tata Electric Companies, Bombay

SHRI H. V. JAIN ( Altematc ) SHRI K. P. N. NAIR Reserve Bank of India, Bombay SHRI S. S. CBERAI Department of Electronics, New Delhi SHRI AsHt.9 SEN SHRI S. K. SENGIJPTA

Indian Statistical Institute,_ Calcutta Indian Airlines, New Delhi

SHRI KAPAL DEV ( Altmut.~ ) SWRI M. hANKRALINGAbl Directorate General of Supplies & Disposals

( Inspection Wing ), New Delhi SHlU M. R. S- Kerala State Electronics Development Corporation

Ltd, Trivandrum SHRI. S. M. V. BHAW ( Alternate )

SHIU C. G. SUBRAMANYAN

SHRI T. N. SWAMY

SHRI R. THIACARAJAN SHRI K. R. VENKATARAMAN

SHRI S. DEVARAJAN ( Al&a&c) SHRI L. P. VENKATARAMAN SHRI R. C. JAIN,

Head ( Electronics)

‘Electronics Trade & Technology Development Corporation Ltd., New Delhi

Electronics Corporation of India Ltd, Hyderabad Department of Science & Technology, New Delhi Hindustan Teleprinters Ltd, Madras

Life Insurance Corporation, Bombay Director General, IS1 ( Ex-o&i0 Member)

secretary

SHRI A. S. RAWAT Assistant Director ( Electronics ), IS1

IS : 1885 ( Part LII/Sec 13 ) - 1980

Indian Standard

ELECTROTECHNICAL VOCABULARY PART LII DATA PROCESSING

Section 13 Analog and Hybrid Computing

0. FOREWORD

0.1 This Indian Standard ( Part LII/Sec 13 ) was adopted by the Indian Standards Institution on 15 September 1980, after the draft finalized by the Basic Standards on Electronics and Telecommunication Sectional Committee, in consultation with Computers Business Machines and Calcu- lators Sectional Committee had been approved by the Electronics and Telecommunication Division Council.

0.2 Electronic data processing is utilized for numerous exchanges and analysis of information of both intellectual and material nature. Application of electronic data processing becomes difficult, either because of the great variety of terms used in various fields to express the same concept, or because of the absence of or the imprecision of useful concepts. To over- come these barriers, this standard has been formulated.

0.3 This standard is one of the series of twenty Indian Standards on data processing vocabulary, constituting the Part LII of the electrotechnical vocabulary, which deals with the main areas of data processing classified under the following heads:

Section 1 Section 2 Section 3 Section 4 Section 5 Section 6 Section 7 Section 8 Section 9 Section 10 Section 11 Section 12 Section 13 Section 14 Section 15 Section 16

Fundamental terms Arithmetic and logic operations Equipment technology Organization of data Representation of data Preparation and handling of data Digital computer programming Control, input-output and arithmetic equipment Data media, storage and related equipment Data communications Operating techniques and facilities Information theory Analog and hybrid computing Computer graphics and computer micrographics Programming languages Data basis

3

IS : 1885 ( Part LII/Sec 13 ) - 1980

Section 17 Data structures Section 18 Information systems characteristics and development Section 19 Reliability, maintenance and availability Section 20 Control and integrity

0.4 Prime importance has been given to simplicity and clarity of the definitions so that they may be understood by all. It may, therefore, be felt that some definitions do not cover all the cases and exceptions.

0.5 Assistance has been derived in formulating this standard from Inter- national Standard IS0 2382 ‘ Data Processing - Vocabulary - Section 19 Analog Computing’, prepared by the International Organization for Standardization.

1. SCOPE

1.1 This standard ( Part LII/Sec 13 ) covers terms related to analog and hybrid computing as used in data processing.

2. FUNCTIONAL UNITS

2.1 Analog Variable - A continuously variable signal representing either a mathematical variable or a physical quantity.

2.2 Operz+ional Amplifier -A high-gain amplifier connected to external elements to perform specific operations or functions.

2.3 Summer/Analog Adder-A functional unit whose output analog variable is equal to the sum, or a weighted sum, of two or more input analog variables,

2.4 Inverter - A functional unit whose output analog variable is equal in magnitude to its input analog variable but is of opposite algebraic sign.

2.5 Coefficient Unit - A functional unit whose output analog variable is equal to the input analog variable multiplied by a constant.

2.6 Analog Multiplier - A functional unit whose output analog variable is proportional to the product of two input analog variables.

NOTE - This term may also be applied to a device that can perform more than one multiplication, for example, a servo multiplier.

2.7 Quarter-Squares Multiplier - An analog multiplier whose opera- tion is based on the identity, xy = [ ( x +r )z- ( x -y )z ] / 4, incorporating inverters, analog adders, and squarelaw function generators.

4

IS t 1885 ( Part LII/Sec 13 ) - 1980

2.8 Analog Divider - A functional unit whose output analog variable is proportional to the quotient of two input analog variables.

2.9 Integrator - A functional unit whose output analog variabIe is the integral of an input analog variable with respect to time.

NOTE - For some integrators, the variable of integration may be other than time.

2.10 Summing Integrator - A functional unit whose output analog variable is the integral of a weighted sum of the input analog variables with respect to time or with respect to another input analog variable.

2.11 Function Generator - A functional unit whose output analog variable is equal to some function of its input analog variables.

2.12 Fixed Function Generator - A function generator in which the function it generates is set by construction and cannot be altered by the user.

2.13 Variable Function Generator-A function generator in which the function it generates may be set by the user before or during computation.

2.14 Comparator ( In Analog Computing ) - A functional unit that compares two analog variables and indicates the result of that comparison.

2.15 Limiter-A functional unit used to prevent an analog variable from exceeding specified limits.

2.16 ‘ Dead Zone’ Unit - A functional unit whose output analog variable is constant over a particular range of the input analog variable.

2.17 Resolver - A functional unit whose input analog variables are the polar coordinates of a point and whose output analog variables are the Cartesian coordinates of the same point, or vice-versa.

2.18 Analog-to-Digital Converter - A functional unit that converts data from an analog representation to a digital representation.

2.19 Digital-to-Analog Converter ( DAC ) - A functional unit that converts data from a digital representation to an analog representation.

2.20 Track and Hold Unit/Track and Store Unit - A functional unit whose output analog variable is equal to either the input analog variable or a sample of this variable selected by the action of an external Boolean signal.

NOTE -When tracking, the device follows the input analog variable; when holding, the device holds the value of the input analog variable at the instant of switching.

5

IS : 1885 ( Part LII/Sec 13 ) - 1980

3. MODES AND OPERATIONS

3.1 Potentiometer Set Mode - That set-up mode of an analog computer during which the coefficients of the problem are set.

3.2 Static Test Mode - That set-up mode of an analog computer during which special initial conditions are set in order to check the patching, and consequently, the proper operation of all computing device except integrators.

3.3 Initial Condition Mode/Reset Mode-That operating mode of an analog computer during which the integrators are inoperative and the initial conditions are set.

3.4 Compute Mode/Operate Mode-That operating mode of an analog computer during which the solution is in progress.

3.5 Hold Mode - That operating mode of an analog computer during which integration is stopped and all variables are held at the value they had when this mode was entered.

3.6 Time Scale Factor - A number used as a multiplier to transform the real time of the problem into computer time.

3.7 Real-Time Operation ( in Analog Computing ) - Operation in the compute mode, during which the time scale factor is 1.

3.8 Repetitive Operation - The automatic repetition of the solution of a set of equations with fixed combinations of initial conditions and other parameters.

NOTE - The repetitive operation is often used to permit the display of an apparently steady solution; it is also used to permit manual adjustment or optimization of one or more parameters.

3.9 Iterative Operation/Automatic Sequential Operation - The repetition of the alogrithm for the solution of equations with successive combinations of initial conditions or other parameters; each successive combination is selected by a subsidiary computation based on a predeter- mined set of iteration rules.

NOTE - Iterative operation is usually used to permit solution of boundry value problems or for automatic optimization of system parameters.

6

i

IS : 1885 ( Part LII/Sec 13 ) - 1980

INDEX NOTE -This index has been prepared in accordance with IS : 1275-1976 l . Index

numbers are clause numbers.

A

Adder, Analog 2.3 Amplifier, Operational 2.2 Analog

adder 2.3 converter ( DAC ), Digital-to- 2.19 divider 2.8 multiplier 2.6 to-diiital converter 2.18 variable 2.1

Automatic sequential operation 3.9

C

Coefficient unit 2.5 Comparator (in analog computing) 2.14 Compute mode 3.4 Condition mode, Initial 3.3 Converter

Analog-to-digital 2.18 ( DAC ) Digital-to-analog 2.19

D

‘ Dead zone ’ unit 2.16 Digital

converter, Analog-to- 2.18 to-Analog converter ( DAC ) 2.19

F

Factor, Time scale 3.6 Fixed function generator 2.12 Function

generator 2.11 Fixed 2.12 Variable 2.13

G

Generator Fixed function 2.12 Function 2.11 Variable function 2.13

H

Hold mode 3.5 Unit, Track and 2.20

I

Initial condition mode 3.3 Integrator 2.9

Summing 2.10 Interative operation 3.9 Inverter 2.4

L

Limiter 2.15

M

Mode Hold 3.5 Initial condition 3.3 Operate 3.4 Reset 3.3 Static test 3.2 Potentiometer set 3.1

Multiplier Analog 2.6 Quarter-squares 2.7

0

Operate mode 3.4 Operation

Automatic sequential 3.9 Interative 3.9 ( in analog computing ) Real-time 3.7 Repetitive 3.8

Operational amplifier 2.2

P

Potentiometer set mode 3.1

Q

Quarter-squares multiplier 2.7

R

Real-time operation ( in Analog Computing) 3.7

Repetitive operation 3.8 Reset mode 3.3 Resolver 2.17

* Rules for making alphabetical indexes (jrst r&&n ).

IS : 1885 ( Part LII/Sec 13 ) - 1980

S

ScaIe factor, Time 3.6 Sequential operation, Automatic 3.9 Set mode, Potentiometer 3.1 Squares multiplier, Quarter 2.7 Static test mode 3.2 Store unit, Track and 2.20 Summer 2.3 Summing integrator 2.10

T

Test mode, Static 3.2 Time

Opex;;i;; ( in analog computing )

Scale factor 3.6 Track

and hold unit 2.20 store unit 2.20

8

U

Unit Coefficient 2.5 ‘ Dead zone ’ 2.16 Track

and hold 2.20 store 2.20

V

Variable Analog 2.1 function generator 2.13