IEC TR 62051:1999

TECHNICAL IEC
REPORT
First edition
1999-03
Electricity metering –
Glossary of terms
Lecture des compteurs électriques –
Glossaire de termes
Reference number
IEC 62051:1999(E)
Numbering
As from 1 January 1997 all IEC publications are issued with a designation in the
60000 series.
Consolidated publications
Consolidated versions of some IEC publications including amendments are
available. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the
base publication, the base publication incorporating amendment 1 and the base
publication incorporating amendments 1 and 2.
Validity of this publication
The technical content of IEC publications is kept under constant review by the IEC,
thus ensuring that the content reflects current technology.
Information relating to the date of the reconfirmation of the publication is available
in the IEC catalogue.
Information on the subjects under consideration and work in progress undertaken
by the technical committee which has prepared this publication, as well as the list
of publications issued, is to be found at the following IEC sources:
• IEC web site*
•
Catalogue of IEC publications
Published yearly with regular updates
(On-line catalogue)*
• IEC Bulletin
Available both at the IEC web site* and as a printed periodical
Terminology, graphical and letter symbols
For general terminology, readers are referred to IEC 60050: International
Electrotechnical Vocabulary (IEV).
For graphical symbols, and letter symbols and signs approved by the IEC for
general use, readers are referred to publications IEC 60027: Letter symbols to be
used in electrical technology, IEC 60417: Graphical symbols for use on equipment.
Index, survey and compilation of the single sheets and IEC 60617: Graphical symbols
for diagrams.
* See web site address on title page.

TECHNICAL IEC
REPORT
First edition
1999-04
Electricity metering –
Glossary of terms
Lecture des compteurs électriques –
Glossaire de termes
 IEC 1999  Copyright - all rights reserved
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Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
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International Electrotechnical Commission
For price, see current catalogue

– 2 – 62051 © IEC:1999(E)
CONTENTS
Page
FOREWORD . 3
Clause
1 Scope . 5
2 Sources of terms. 5
3 Acronyms and abbreviations. 6
4 General. 9
5 Utility systems/services . 12
6 Physical meters and metering. 14
7 Meter reading. 16
8 Demand . 17
9 Billing and tariffs . 18
10 Load management and load control . 21
11 Distribution system automation. 22
12 Open systems interconnection. 24
13 Data communications . 27
14 Distribution automation using DLC media . 37
15 Quality . 42
16 DLMS vocabulary . 44
17 Pre-payment electricity metering. 45
18 Dependability .51
19 Liberalized utility market. 52
Index. 54

62051 © IEC:1999(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICITY METERING –
GLOSSARY OF TERMS
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International Organization
for Standardization (ISO) in accordance with conditions determined by agreement between the two
organizations.
2) The formal decisions or agreements of the IEC on technical matters express, as nearly as possible, an
international consensus of opinion on the relevant subjects since each technical committee has representation
from all interested National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this technical report may be the subject of
patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
The main task of IEC technical committees is to prepare International Standards. However, a
technical committee may propose the publication of a technical report when it has collected
data of a different kind from that which is normally published as an International Standard, for
example "state of the art".
Technical reports do not necessarily have to be reviewed until the data they provide are
considered to be no longer valid or useful.
IEC 62051, which is a technical report, has been prepared by IEC technical committee 13:
Equipment for electrical energy measurement and load control.
The text of this technical report is based on the following documents:
Enquiry draft Report on voting
13/1151/CDV 13/1178/RVC
Full information on the voting for the approval of this technical report can be found in the report
on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
This document, which is purely informative, is not to be regarded as an International Standard.

– 4 – 62051 © IEC:1999(E)
The definitions in this glossary are intended to assist in understanding the work of technical
committee 13.
The preparation of this report is based on the
• Australian Standard AS 4140.
In addition, the following standard organizations have contributed to the preparation of this
technical report:
• CEN technical committee 294, working group 2;
• USA and Canada AMRA/AMSI/IC/IEEE joint working group.

62051 © IEC:1999(E) – 5 –
ELECTRICITY METERING –
GLOSSARY OF TERMS
1 Scope
This technical report provides definitions of specific terms which may be used for drafting
standards for electrical energy measurement, tariff and load control, and customer/utility
information exchange systems.
Standards and technical reports which deal with Distribution Automation Systems (DAS) using
Distribution Line Carrier (DLC) systems use a number of terms with specific meaning, which
are not defined in IEC 60050(371). The present technical report includes these terms and their
definitions, as well as those terms that are already defined in IEC 60050(371). It presents a
comprehensive means of referring to terms used in standard documents on customer/utility
information exchange (CUIE) systems prepared or being prepared by IEC TC 13.
This report also incorporates specific terms used in present and future standards on electricity
pre-payment systems, and specific terms concerning the dependability of electricity metering
equipment.
2 Sources of terms
The following documents were used to establish this glossary of terms.
General terms given in the IEC 60050 series are repeated with reference to the appropriate IEV
term. Other sources are identified by a figure in brackets which refers to the following list:
(1) American National Standards Institute: IEEE Standard Dictionary of Electrical and
Electronics Terms (1984)
(2) IEC 60050(351): International Electrotechnical Vocabulary (IEV) – Chapter 351:
Automatic control
(3) IEC 60050(721):1992, International Electrotechnical Vocabulary (IEV) – Chapter 721:
Telegraphy, facsimile and data communication
(4) ISO/IEC 2382-9:1995, Information technology – Vocabulary – Part 9: Data communication
(5) Australian Standard AS 4140-1995: Metering and utility information exchange – Glossary
of terms
(6) IEC 60050(191):1990, International Electrotechnical Vocabulary (IEV) – Chapter 191:
Dependability and quality of service
(7) IEC/TR3 60870-1-3:1997, Telecontrol equipment and systems – Part 1: General
considerations – Section 3: Glossary
(8) ISO/IEC 7498-1:1994, Information technology – Open Systems Interconnection – Basic
Reference Model – The Basic Model
(9) ISO/IEC 10731:1994, Information technology – Open Systems Interconnection – Basic
Reference Model – Conventions for the definition of OSI services (source: ITU-T X.210:
1993)
(10) IEC 60050(161):1990, International Electrotechnical Vocabulary (IEV) – Chapter 161:
Electromagnetic compatibility
– 6 – 62051 © IEC:1999(E)
(11) ISO 8402:1994, Quality management and quality assurance – Vocabulary
(12) South African Specification NRS009-1. Electricity Sales Systems – Part 1: Glossary and
System Overview. (Subsequently published as South African Standard: SABS 1524-0)
(13) IEC 60050(691):1973, International Electrotechnical Vocabulary (IEV) – Chapter 691:
Tariffs for electricity
(14) ISO/IEC 2382-14:1997, Information technology – Vocabulary – Part 14: Reliability,
maintainability and availability
(15) IEC 61107:1996, Data exchange for meter reading, tariff and load control – Direct local
data exchange
(16) IEC 61134-4-41:1996, Distribution automation using distribution line carrier systems –
Part 4: Data communication protocols – Section 41: Application protocol distribution line
message specification
(17) ISO/IEC 9506-1:1990, Industrial automation systems – Manufacturing message specification –
Part 1: Service definition
(18) ISO/IEC 9506-2:1990, Industrial automation systems – Manufacturing message specification –
Part 2: Protocol specification
(19) ISO 8824:1990, Information technology – Open Systems Interconnection – Specification of
Abstract Syntax Notation One (ASN.1) (Provisionally retained edition)
(20) ISO 8825:1990, Information technology – Open Systems Interconnection – Specification of
Basic Encoding Rules for Abstract Syntax Notation One (ASN.1) (Provisionally retained edition)
(21) IEC 60050(371):1984, International Electrotechnical Vocabulary (IEV) – Chapter 371:
Telecontrol
(22) IEC 60050(702):1992, International Electrotechnical Vocabulary (IEV) – Chapter 702:
Oscillations, signals and related devices
3 Acronyms and abbreviations
AP Application Process (application layer/OSI)
API Application Program Interface
ASK Amplitude Shift Keying
ASN.1 Abstract Syntax Notation 1 (ISO 8824)
A-XDR Adapted eXternal Data Representation – (IEC TC 57 WG 09 NWIP)
BER Basic Encoding Rules – ISO 8825
CA Customer Authorization
*
CAU * Customer Automation Unit
CEN European Committee for Standardization
CENELEC Comité Européen de Normalisation ELECtrotechnique
CCG* Customer Communication Gateway
CCITT Comité Consultatif International Télégraphique et Téléphonique (see ITU-T)
CCT Complex Control Transducer
CI* Central Interface
CLI* Central Low Voltage Interface
________
*
These terms are used in some countries.

62051 © IEC:1999(E) – 7 –
CLCU* Central Low Voltage Communication Unit
CLPU* Central Low Voltage Processing Unit
CLU* Central Low Voltage Unit
CMCU* Central Medium Voltage Communication Unit
CMI* Central Medium Voltage Interface
CMPU* Central Medium Voltage Processing Unit
CMT Complex Measuring Transducer
CMU* Central Medium Voltage Unit
CPE* Customer Premises Equipment
CPU Central Processing Unit
∗
CU Control Unit
CVS Common Vending System
C&M* Control and Metering Unit
DA Distribution Automation
DAS Distribution Automation System
dB Decibel
dBm dB referred to 1 mW at 600 Ω
DCE Data Circuit-terminating Equipment
DES Data Encryption Standard
DFM Distributed
...