SIST EN 62056-42:2004

SLOVENSKI STANDARD
SIST EN 62056-42:2004
01-januar-2004
Electricity metering - Data exchange for meter reading, tariff and load control - Part
42: Physical layer services and procedures for connection-oriented asynchronous
data exchange (IEC 62056- 42:2002)
Electricity metering - Data exchange for meter reading, tariff and load control -- Part 42:
Physical layer services and procedures for connection-oriented asynchronous data
exchange
Messung der elektrischen Energie - Zählerstandsübertragung, Tarif- und Laststeuerung -
- Teil 42: Bitübertragungsschichtdienste und Verfahren für verbindungsorientierten
asynchronen Datenaustausch
Equipements de mesure de l'énergie électrique - Echange des données pour la lecture
des compteurs, le contrôle des tarifs et de la charge -- Partie 42: Services et procédures
de la couche physique pour l'échange de données à l'aide de connexion asynchrone
Ta slovenski standard je istoveten z: EN 62056-42:2002
ICS:
17.220.20 0HUMHQMHHOHNWULþQLKLQ Measurement of electrical
PDJQHWQLKYHOLþLQ and magnetic quantities
35.100.10 )L]LþQLVORM Physical layer
91.140.50 Sistemi za oskrbo z elektriko Electricity supply systems
SIST EN 62056-42:2004 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 62056-42:2004

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SIST EN 62056-42:2004
EUROPEAN STANDARD EN 62056-42
NORME EUROPÉENNE
EUROPÄISCHE NORM June 2002
ICS 91.140.50; 35.100.10
English version
Electricity metering -
Data exchange for meter reading, tariff and load control
Part 42: Physical layer services and procedures
for connection-oriented asynchronous data exchange
(IEC 62056-42:2002)
Equipements de mesure Messung der elektrischen Energie -
de l'énergie électrique - Zählerstandsübertragung,
Echange des données pour la lecture Tarif- und Laststeuerung
des compteurs, le contrôle des tarifs Teil 42: Bitübertragungsschichtdienste
et de la charge und Verfahren für verbindungsorientierten
Partie 42: Services et procédures asynchronen Datenaustausch
de la couche physique pour l'échange (IEC 62056-42:2002)
de données à l'aide de connexion
asynchrone
(CEI 62056-42:2002)
This European Standard was approved by CENELEC on 2002-03-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2002 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62056-42:2002 E

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SIST EN 62056-42:2004
EN 62056-42:2002 - 2 -
Foreword
The text of document 13/1266/FDIS, future edition 1 of IEC 62056-42, prepared by IEC TC 13,
Equipment for electrical energy measurement and load control, was submitted to the IEC-CENELEC
parallel vote and was approved by CENELEC as EN 62056-42 on 2002-03-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-01-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2005-03-01
The International Electrotechnical Commission (IEC) and CENELEC draw attention to the fact that it is
claimed that compliance with this International Standard / European Standard may involve the use of a
maintenance service concerning the stack of protocols on which the present standard
IEC 62056-42 / EN 62056-42 is based.
The IEC and CENELEC take no position concerning the evidence, validity and scope of this
maintenance service.
The provider of the maintenance service has assured the IEC that he is willing to provide services under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this
respect, the statement of the provider of the maintenance service is registered with the IEC. Information
(see also 6.3.3) may be obtained from:
1)
DLMS User Association
Geneva / Switzerland
www.dlms.ch
Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annexe ZA is normative and annexes A and B are informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62056-42:2002 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 61334-4-41 NOTE Harmonized as EN 61334-4-41:1996 (not modified).
IEC 61334-6 NOTE Harmonized as EN 61334-6:2000 (not modified).
__________

1)
Device Language Message Specification

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SIST EN 62056-42:2004
- 3 - EN 62056-42:2002
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60050-300 2001 International Electrotechnical --
Vocabulary - Electrical and electronic
measurements and measuring
instruments
Part 311: General terms relating to
measurements
Part 312: General terms relating to
electrical measurements
Part 313: Types of electrical measuring
instruments
Part 314: Specific terms according to
the type of instrument
IEC/TR 62051 1999 Electricity metering - Glossary of terms - -
IEC 62056-21 2002 Electricity metering - Data exchange for EN 62056-21 2002
meter reading, tariff and load control
Part 21: Direct local data exchange
IEC 62056-46 2002 Part 46: Data link layer using HDLC EN 62056-46 2002
protocol
IEC 62056-53 2002 Part 53: COSEM application layer EN 62056-53 2002
IEC 62056-61 2002 Part 61: Object identification system EN 62056-61 2002
(OBIS)
IEC 62056-62 2002 Part 62: Interface classes EN 62056-62 2002
NEMA C12.21 1999 Protocol Specification for Telephone--
Modem Communication

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SIST EN 62056-42:2004

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SIST EN 62056-42:2004
INTERNATIONAL IEC
STANDARD
62056-42
First edition
2002-02
Electricity metering –
Data exchange for meter reading,
tariff and load control –
Part 42:
Physical layer services and procedures
for connection-oriented asynchronous
data exchange
 IEC 2002  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission 3, rue de Varembé Geneva, Switzerland
Telefax: +41 22 919 0300 e-mail: inmail@iec.ch IEC web site http://www.iec.ch
Commission Electrotechnique Internationale
PRICE CODE
U
International Electrotechnical Commission
For price, see current catalogue

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SIST EN 62056-42:2004
– 2 – 62056-42  IEC:2002(E)
CONTENTS
FOREWORD .4
1 Scope.5
2 Normative references .5
3 Terms, definitions and abbreviations .6
4 Overview .7
5 Service specification.8
5.1 List of services .8
5.1.1 Connection establishment/release related services.8
5.1.2 Data communication services .8
5.1.3 Layer management services .8
5.2 Use of the physical layer services .9
5.3 Service definitions .9
5.3.1 PH-CONNECT.request .9
5.3.2 PH-CONNECT.indication .10
5.3.3 PH-CONNECT.confirm .10
5.3.4 PH-ABORT.request .11
5.3.5 PH-ABORT.confirm .11
5.3.6 PH-ABORT.indication .11
5.3.7 PH-DATA.request .12
5.3.8 PH-DATA.indication.12
6 Protocol specification .13
6.1 Physical layer protocol data unit.13
6.2 Transmission order and characteristics .13
6.3 Physical layer operation – description of the procedures .13
6.3.1 General .13
6.3.2 Setting up a physical connection .14
6.3.3 The identification service .15
6.3.4 Data communications .19
6.3.5 Disconnection of an existing physical connection.19
Annex A (informative) An example: PH service primitives and Hayes commands .20
Annex B (informative) Data model and protocol .25
Bibliography.26
Figure 1 – Typical PSTN configuration .7
Figure 2 – The location of the physical layer .8
Figure 3 – Protocol layer services of the COSEM 3-layer connection oriented profile.9
Figure 4 – MSC for physical connection establishment.15
Figure 5 – MSC for IDENTIFY.request/.response message exchange .17
Figure 6 – Handling the identification service at the COSEM server side.17
Figure 7 – Partial state machine for the client side physical layer.18
Figure A.1 – MSC for physical connection request .20
Figure A.2 – Physical connection establishment at the CALLING station.21
Figure A.3 – MSC for physical connection establishment .22
Figure A.4 – Data exchange between the calling and called stations.23
Figure A.5 – MSC for a physical disconnection .24
Figure B.1 – The three-step approach of COSEM .25

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SIST EN 62056-42:2004
62056-42  IEC:2002(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
___________
ELECTRICITY METERING – DATA EXCHANGE
FOR METER READING, TARIFF AND LOAD CONTROL –
Part 42: Physical layer services and procedures for
connection-oriented asynchronous data exchange
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.
The International Electrotechnical Commission (IEC) draws attention to the fact that it is claimed that compliance
with this International Standard may involve the use of a maintenance service concerning the stack of protocols on
which the present standard IEC 62056-42 is based.
The IEC takes no position concerning the evidence, validity and scope of this maintenance service.
The provider of the maintenance service has assured the IEC that he is willing to provide services under
reasonable and non-discriminatory terms and conditions for applicants throughout the world. In this respect, the
statement of the provider of the maintenance service is registered with the IEC. Information (see also 6.3.3) may
be obtained from:
1
DLMS User Association
Geneva / Switzerland
www.dlms.ch
International Standard IEC 62056-42 has been prepared by IEC technical committee 13:
Equipment for electrical energy measurement and load control.
The text of this standard is based on the following documents:
FDIS Report on voting
13/1266/FDIS 13/1272/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
_________
1
 Device Language Message Specification.

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SIST EN 62056-42:2004
– 4 – 62056-42  IEC:2002(E)
This publication has been drafted in accordance with the ISO/IEC Directives, Part 3.
Annexes A and B are for information only.
The committee has decided that the contents of this publication will remain unchanged until
2006. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

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SIST EN 62056-42:2004
62056-42  IEC:2002(E) – 5 –
ELECTRICITY METERING – DATA EXCHANGE
FOR METER READING, TARIFF AND LOAD CONTROL –
Part 42: Physical layer services and procedures for
connection-oriented asynchronous data exchange
1 Scope
This part of IEC 62056 specifies the physical layer services and protocols within the
Companion Specification for Energy Metering (COSEM) three-layer connection oriented
profile for asynchronous data communication. The document does not specify physical layer
signals and mechanical aspects. Local, implementation-specific issues are also not specified.
In annex A, an example of how this physical layer can be used for data exchange through the
Public Switched Telephone Network (PSTN) using intelligent Hayes modems is given.
The use of the physical layer for the purposes of direct local data exchange using an optical
port or a current loop physical interface is specified in IEC 62056-21.
Annex B gives an explanation of the role of data models and protocols in electricity meter
data exchange.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
IEC 60050-300:2001, International Electrotechnical Vocabulary –Electrical and electronic
measurements and measuring instruments – Part 311: General terms relating to
measurements – Part 312: General terms relating to electrical measurements – Part 313:
Types of electrical measuring instruments – Part 314: Specific terms according to the type of
instrument
IEC/TR 62051:1999, Electricity metering – Glossary of terms
IEC 62056-21, Electricity metering – Data exchange for meter reading, tariff and load control –
1
Part 21: Direct local data exchange
IEC 62056-46, Electricity metering – Data exchange for meter reading, tariff and load control –
1
Part 46: Data link layer using HDLC protocol
IEC 62056-53, Electricity metering – Data exchange for meter reading, tariff and load control –
1
Part 53: COSEM application layer
IEC 62056-61, Electricity metering – Data exchange for meter reading, tariff and load control
1
– Part 61: OBIS Object identification system
IEC 62056-62, Electricity metering – Data exchange for meter reading, tariff and load control –
1
Part 62: Interface objects
NEMA C12.21:1999, Protocol Specification for Telephone Modem Communication
_________
1
 To be published.

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SIST EN 62056-42:2004
– 6 – 62056-42  IEC:2002(E)
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purpose of this part of IEC 62056, the definitions in IEC 60050-300 and IEC/TR 62051
as well as the following definitions apply:
3.1.1
client
a station asking for services, normally the master station
3.1.2
master
central station – station which takes the initiative and controls the data flow
3.1.3
server
a station delivering services. The tariff device (meter) is normally the server, delivering the
requested values or executing the requested tasks
3.1.4
slave
station responding to requests of a master station. The tariff device (meter) is normally a
slave station
3.2 Abbreviations
COSEM COmpanion Specification for Energy Metering
DCE Data Communication Equipment (communications interface or modem)
DTE Data Terminal Equipment (computers, terminals or printers)
MSC Message Sequence Chart
PDU Protocol Data Unit
PH PHysical layer
PHPDU PHysical layer Protocol Data Unit
PHSDU PHysical layer Service Data Unit
SDU Service Data Unit

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SIST EN 62056-42:2004
62056-42  IEC:2002(E) – 7 –
4 Overview
From the external point of view, the physical layer provides the interface between the
DTE and the DCE, see
Figure 2. Figure 1 shows a typical configuration for data exchange through a wide area
network, for example the PSTN.
COSEM server
COSEM client
DTE DTE
DCE
DCE
Schlumberger
kWh
Transit network 00001,6
(o)  N° 00012356
10 (40)A 230V 50Hz
DTE to DCE DCE to DTE
ITU-T V series ITU-T V series
EIA RS232, RS485 EIA RS232, RS485
Hayes, etc. Hayes, etc
IEC  235/02
Figure 1 – Typical PSTN configuration
From the physical connection point of view, all communications involve two sets of equipment
represented by the terms caller system and called system. The caller is the system that
decides to initiate a communication with a remote system known as the called party; these
denominations remain valid throughout the duration of the communication. A communication
is broken down into a certain number of transactions. Each transaction is represented by a
transmission from the transmitter to the receiver. During the sequence of transactions, the
caller and called systems take turns to act as transmitter and receiver.
From the data link point of view the central station normally acts as a master, taking the
initiative and controlling the data flow. The tariff device is the slave, responding to the master
station.
From the application point of view the central station normally acts as a client asking for
services, and the tariff device acts as a server delivering the requested services.
The situation involving a caller client and a called server is undoubtedly the most frequent
case, but a communication based on a caller server and a called client is also possible, in
particular to report the occurrence of an urgent alarm.
For the purpose of local data exchange, two DTEs can be directly connected using
appropriate connections.
To allow using a wide variety of media, this standard does not specify the physical layer
signals and their characteristics. However, the following assumptions are made:
• the communication is point to point or point to multipoint;
• both half-duplex and duplex connections are possible;
• asynchronous transmission with 1 start bit, 8 data bits, no parity and 1 stop bit (8N1).

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SIST EN 62056-42:2004
– 8 – 62056-42  IEC:2002(E)
From the internal point of view, the physical layer is the lowest layer in the protocol stack.
COSEM client COSEM server
DTE
DTE
Server
Client
application
application
Application
Application
Transit network layer
layer
Data
Data
Data Link
Data Link
comm.
comm.
layer
layer
equipment
equipment
Physical
(DCE)
Physical
(DCE)
layer
layer
IEC  236/02
Figure 2 – The location of the physical layer
This standard defines the services of the physical layer towards its peer layer(s) and the
upper layers, and the protocol of the physical layer.
5 Service specification
5.1 List of services
ITU-T X.211 defines a set of capabilities to be made available by the physical layer over the
physical media. These capabilities are available via service primitives, as follows:
5.1.1 Connection establishment/release related services
PH-CONNECT.request / PH-CONNECT.indication / PH-CONNECT.confirm
PH-ABORT.request / PH-ABORT.confirm / PH-ABORT.indication
5.1.2 Data communication services
PH-DATA.request / PH-DATA.indication
5.1.3 Layer management services
In addition to the services above, some additional physical layer services may be necessary,
which are used by or provided for the layer management process, which is part of the
application process. Some examples are given below:
PH-INITIALIZE.request / PH-INITIALIZE.confirm
PH-GET_VALUE.request / PH-GET_VALUE.confirm
PH-SET_VALUE.request / PH-SET_VALUE.confirm
PH-LM_EVENT.indication
As these services are of local importance only, their definition is not within the scope of this
standard.
Protocol
Protocol

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SIST EN 62056-42:2004
62056-42  IEC:2002(E) – 9 –
5.2 Use of the physical layer services
Figure 3 shows how different service users use the service primitives of the physical layer.
Physical
Layer management
connection
Application process
process manager
ASO services
AL management
services
Application layer
Connect/disconnect and
data related services
DL management
services
Data link layer
PH-DATA.req /.ind
PH-ABORT.ind
PH management
services
Physical layer
IEC  237/02
Figure 3 – Protocol layer services of the COSEM 3-layer connection oriented profile
As is shown in Figure 3, the connection establishment/release services are used by and
provided for the physical connection manager application process, and not the data link layer.
The reasons for this are explained in 6.3.1.
5.3 Service definitions
5.3.1 PH-CONNECT.request
Function
This primitive is invoked by the service user entity to request the setting up of a physical
connection to a remote device.
NOTE In the COSEM environment, it is the physical connection manager application process.
Service parameters
The semantics of the primitive is as follows:
PH-CONNECT.request
(
PhConnType,
PhConnReqParams
)
The PhConnType parameter specifies the type of connection requested, for example direct
connection, PSTN modem connection, etc. This standard does not specify data/type(s) and/or
value(s) for this parameter, because this is a local issue only.
Application
Protocol
PH-CONNECT.req /.cnf /.ind
PH-ABORT.req /.cnf /.ind
PH-DATA.req /.ind

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SIST EN 62056-42:2004
– 10 – 62056-42  IEC:2002(E)
The structure and the contents of the PhConnReqParams parameter depend on the value of
the PhConnType parameter. For example, in the case of a PSTN connection it includes the
phone number of the remote station, etc. As – similarly to the PhConnType parameter – the
PhConnReqParams parameter contains implementation dependent data, data types/values for
this parameter are not specified in this standard.
Use
The PH-CONNECT.request primitive is used for the establishment of a physical connection.
The receipt of this primitive causes the PH-Layer entity to perform the required actions, for
example dial the specified phone number, to establish a physical connection with the peer
physical layer entity. An example of these actions in the case of an intelligent Hayes modem
is given in annex A.
5.3.2 PH-CONNECT.indication
Function
This primitive is generated by the physical layer entity to indicate to the service user entity
that a remote device requests that a physical connection to the local physical layer be
established.
Service parameters
The semantics of the primitive is as follows:
PH-CONNECT.indication ( )
Use
The PH-CONNECT.indication primitive is used by the PH entity to indicate to the service user
entity that a remote device requests that a physical connection be established.
5.3.3 PH-CONNECT.confirm
Function
This primitive is generated by the PH entity to convey the results of the associated PH-
CONNECT.request to the service user entity.
Service parameters
The semantics of the primitive is as follows:
PH-CONNECT.confirm
(
Result,
PhConnCnfParams
)
The result parameter indicates whether the attempt to set up a physical connection was
successful or not.
The structure and the value of the PhConnCnfParams parameter depend on the physical
connection type of the corresponding CONNECTION.request service, which is actually being
confirmed. For example, in the case of a PSTN connection it may include parameters of the
established connection (V22, baud-rate, etc.). Data types and values for either the Result or
the PhConnCnfParams parameter are not specified in this standard.
If the connection could not be established due to a local error – for example the phone line is
not available – the PH-CONNECT.confirm service is locally generated.

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SIST EN 62056-42:2004
62056-42  IEC:2002(E) – 11 –
Use
The PH-CONNECT.confirm primitive is used by the PH entity to convey the results of the
associated PH-CONNECT.request.
5.3.4 PH-ABORT.request
Function
This primitive is invoked by the service user entity to request the disconnection of an existing
physical connection.
Service pa
...