EN IEC 62056-3-1:2021

SLOVENSKI STANDARD
01-november-2021
Nadomešča:
SIST EN 62056-3-1:2014
Izmenjava podatkov meritev električne energije - Niz DLMS/COSEM - 3-1. del:
Uporaba lokalnih omrežij prek zvitih parov s signalizacijo po nosilcu
Electricity metering data exchange - The DLMS/COSEM suite - Part 3-1: Use of local
area networks on twisted pair with carrier signalling
Ta slovenski standard je istoveten z: EN IEC 62056-3-1:2021
ICS:
17.220.20 Merjenje električnih in Measurement of electrical
magnetnih veličin and magnetic quantities
35.110 Omreževanje Networking
91.140.50 Sistemi za oskrbo z elektriko Electricity supply systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 62056-3-1

NORME EUROPÉENNE
EUROPÄISCHE NORM August 2021
ICS 17.220.20; 35.110; 91.140.50 Supersedes EN 62056-3-1:2014 and all of its
amendments and corrigenda (if any)
English Version
Electricity metering data exchange - The DLMS/COSEM suite -
Part 3-1: Use of local area networks on twisted pair with carrier
signalling
(IEC 62056-3-1:2021)
Échange des données de comptage de l'électricité - La Datenkommunikation der elektrischen Energiemessung -
suite DLMS/COSEM - Partie 3-1: Utilisation des réseaux DLMS/COSEM - Teil 3-1: Nutzung lokaler Netzwerke mit
locaux sur paire torsadée avec signal de porteuse Trägerfrequenz-Signalübertragung auf verdrillten
(IEC 62056-3-1:2021) Zweidrahtleitungen
(IEC 62056-3-1:2021)
This European Standard was approved by CENELEC on 2021-08-11. 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 CEN-CENELEC
Management Centre 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 CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 62056-3-1:2021 E

European foreword
The text of document 13/1794/CDV, future edition 2 of IEC 62056-3-1, prepared by IEC/TC 13
“Electrical energy measurement and control” was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 62056-3-1:2021.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2022–05–11
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2024–08–11
document have to be withdrawn
This document supersedes EN 62056-3-1:2014 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
This document has been prepared under a Standardization Request given to CENELEC by the
European Commission and the European Free Trade Association.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 62056-3-1:2021 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 62056-6-1:2017 NOTE Harmonized as EN 62056-6-1:2017 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the
relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 61334-4-41 1996 Distribution automation using distribution EN 61334-4-41 1996
line carrier systems - Part 4: Data
communication protocols - Section 41:
Application protocol - Distribution line
message specification
IEC 62056-5-3 2017 Electricity metering data exchange - The EN 62056-5-3 2017
DLMS/COSEM suite - Part 5–3:
DLMS/COSEM application layer
IEC 62056-6-2 2017 Electricity metering data exchange - The EN IEC 62056-6-2 2018
DLMS/COSEM suite - Part 6–2: COSEM
interface classes
IEC 62056-51 1998 Electricity metering - Data exchange for - -
meter reading, tariff and load control - Part
51: Application layer protocols
ISO/IEC 8482 1993 Information technology - - -
Telecommunications and information
exchange between systems - Twisted pair
multipoint interconnections
EIA 485 - Electrical characteristics of generators and - -
receivers for use in balanced digital
multipoint systems
IEC 62056-3-1 ®
Edition 2.0 2021-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Electricity metering data exchange – The DLMS/COSEM suite –

Part 3-1: Use of local area networks on twisted pair with carrier signalling

Échange des données de comptage de l'électricité – La suite DLMS/COSEM –

Partie 3-1: Utilisation des réseaux locaux sur paire torsadée avec signal de

porteuse
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 17.220.20; 35.110; 91.140.50 ISBN 978-2-8322-9940-1

– 2 – IEC 62056-3-1:2021 © IEC 2021
CONTENTS
FOREWORD . 6
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 9
3.1 Terms and definitions. 9
3.2 Abbreviated terms . 9
4 General description . 10
4.1 Basic vocabulary . 10
4.2 Profiles, layers and protocols . 11
4.3 Specification language . 12
4.4 Communication services for local bus data exchange without DLMS . 12
4.5 Communication services for local bus data exchange with DLMS . 21
4.6 Systems management . 22
5 Local bus data exchange without DLMS . 23
5.1 Physical layer . 23
5.2 Data Link layer . 35
5.3 Application layer . 43
6 Local bus data exchange with DLMS . 46
6.1 Physical layer . 46
6.2 Data Link layer . 47
6.3 Application layer . 56
7 Local bus data exchange with DLMS/COSEM . 56
7.1 Model . 56
7.2 Physical Layer . 56
7.3 Data Link layer . 67
7.4 Support Manager layer . 76
7.5 Transport Layer . 80
7.6 Application Layer . 84
8 Local bus data exchange – Hardware . 85
8.1 General . 85
8.2 General characteristics . 85
8.3 Bus specification . 90
8.4 Magnetic plug . 92
8.5 Functional specifications of Primary Station transmitter (for 50 kHz signal) . 94
8.6 Functional specifications of Primary Station receiver (for 50 kHz signal) . 95
8.7 Functional specification of Secondary Station transmitter (for 50 kHz signal) . 96
8.8 Functional specifications of Secondary Station receiver (for 50 kHz signal) . 97
9 Unidirectional local data transmission interface . 98
9.1 Introduction . 98
9.2 General description . 98
9.3 Historical TIC . 98
9.4 Standard TIC . 102
9.5 Unidirectional TIC Hardware . 103
Annex A (normative) Specification language . 110
A.1 Vocabulary and operating rules . 110

IEC 62056-3-1:2021 © IEC 2021 – 3 –
A.2 Entity and Entity Invocation . 111
Annex B (normative) Timing types and characteristics . 112
B.1 Timing type definition . 112
B.2 Timing measurements and characteristics. 113
Annex C (normative) List of fatal errors . 114
Annex D (normative) Coding the command code field of frames . 115
D.1 Command codes for local bus data exchange (Table D.1) . 115
D.2 Codes of commands for data exchange on the local bus with DLMS or
DLMS/COSEM . 115
Annex E (normative) Principle of the CRC . 117
E.1 General . 117
E.2 Operations on the polynomials . 117
E.3 Check procedure. 117
E.4 Operating parameters . 118
Annex F (normative) Random integer generation for response from forgotten stations . 119
F.1 General . 119
F.2 Criterion for a random integer . 119
F.3 Operating parameters . 119
Annex G (normative) Random number generation for authentication (profile without

DLMS) . 120
Annex H (normative) Systems management implementation . 121
Annex I (informative) Information about exchanges . 122
I.1 Non-energized station session (Figure I.1) . 122
I.2 Remote reading and programming exchanges (Figure I.2) . 123
I.3 Bus initialization frame (Figure I.3). 124
I.4 Forgotten station call exchange (Figure I.4) . 125
Bibliography . 126

Figure 1 – IEC 62056-3-1 communication profiles . 11
Figure 2 – Alarm mechanism . 21
Figure 3 – Exchanges in continuous operation . 25
Figure 4 – Alarm event without any communication in progress . 26
Figure 5 – Alarm event with a communication in progress . 26
Figure 6 – Signal envelope on the bus . 86
Figure 7 – Bus representation . 87
Figure 8 – Power supply characteristics . 87
Figure 9 – States associated to a session: for selected Secondary Station . 88
Figure 10 – States associated to a session: for non-selected Secondary Station. 88
Figure 11 – Simple and multiple Secondary stations . 89
Figure 12 – Equivalent diagram of the test equipment . 91
Figure 13 – Ferrite pot and bobbin . 92
Figure 14 – Associated components of the magnetic plug . 93
Figure 15 – Associated components of the energy supply plug . 94
Figure 16 – Character transmission . 99
Figure 17 – Historical TIC: information group structure . 100
Figure 18 – Standard TIC: Application information group structure . 102

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Figure 19 – Standard TIC: Timestamped information group structure . 102
Figure 20 – Equivalent diagram of the test equipment . 106
Figure 21 – Signal envelope on the bus . 107
Figure B.1 – Logical timing type . 112
Figure B.2 – Physical timing type . 112
Figure B.3 – Results processing for timing defined with low and high limits . 113
Figure B.4 – Results processing for timing defined by a nominal value . 113
Figure I.1 – Non-energized station session . 122
Figure I.2 – Remote reading and programming exchanges . 123
Figure I.3 – Bus initialization . 124
Figure I.4 – Forgotten station call exchange. 125

Table 1 – Primary Station timing . 24
Table 2 – Secondary Station timing . 25
Table 3 – Physical services and service primitives . 26
Table 4 – Physical-62056-3-1 state transitions: Primary Station . 27
Table 5 – Power supply management state transitions (only for non-energized
Secondary Station) . 30
Table 6 – Physical-62056-3-1 state transitions: Secondary Station . 31
Table 7 – Meaning of the states listed in the previous tables. 32
Table 8 – Definition of the procedures, functions and events classified in alphabetical

order . 33
Table 9 – Error summary table . 35
Table 10 – Data Link services and service primitives . 36
Table 11 – Link-62056-3-1 state transitions: Primary Station . 37
Table 12 – Link-62056-3-1 State transitions: Secondary Station . 40
Table 13 – Meaning of the states listed in the previous tables . 41
Table 14 – Definition of the procedures and functions classified in alphabetical order . 41
Table 15 – Error summary table . 42
Table 16 – Application services and service primitives . 43
Table 17 – Application-62056-3-1 state transitions: Primary Station . 44
Table 18 – Application-62056-3-1 state transitions: Secondary Station . 45
Table 19 – Meaning of the states listed in the previous tables . 45
Table 20 – Definition of the procedures and functions classified in alphabetical order . 46
Table 21 – Error summary table . 46
Table 22 – Data Link services and service primitives . 48
Table 23 – Link-E/D state transitions: Primary Station . 49
Table 24 – Link-E/D state transitions: Secondary Station . 51
Table 25 – Meaning of the states listed in the previous tables . 53
Table 26 – Definition of the procedures and functions classified in alphabetical order . 54
Table 27 – Error summary table . 55
Table 28 – Client_connect function definition . 56
Table 29 – E/COSEM Physical services and service primitives . 57
Table 30 – E/COSEM Physical state transitions: Primary Station . 59

IEC 62056-3-1:2021 © IEC 2021 – 5 –
Table 31 – Power supply management state transitions (only for non-energized
Secondary Station) . 61
Table 32 – E/COSEM Physical State transitions: Secondary Station . 63
Table 33 – Meaning of the states listed in the previous tables . 64
Table 34 – Definition of the procedures, functions and events classified in alphabetical

order . 65
Table 35 – Error summary table . 67
Table 36 – Data Link services and service primitives . 68
Table 37 – DLMS/COSEM Data Link E/D state transitions: Primary Station. 70
Table 38 – DLMS/COSEM Link E/D state transitions: Secondary Station . 72
Table 39 – Meaning of the states listed in the previous tables . 74
Table 40 – Definition of the procedures and functions classified in alphabetical order . 75
Table 41 – Commands managed by the Support Manager layer . 76
Table 42 – List of parameters . 78
Table 43 – Support Manager layer state transitions: Primary Station. 78
Table 44 – Support Manager layer state transitions: Secondary Station . 79
Table 45 – Meaning of the states listed in the previous table . 79
Table 46 – Definition of procedures, functions and events . 79
Table 47 – Transport services and services primitive . 81
Table 48 – Transport state transitions . 81
Table 49 – Meaning of the states listed in the previous table . 83
Table 50 – Definition of the procedures and functions classified in alphabetical order . 83
Table 51 – Primary station transmitter: Tev0 and Tev1 values . 95
Table 52 – Primary station receiver: Tev0 and Tev1 values . 95
Table 53 – Secondary station transmitter: Tev0 and Tev1 values . 96
Table 54 – Secondary station receiver: Tev0 and Tev1 values . 97
Table 55 – TIC terminal board pin out . 104
Table 56 – Power supply characteristics . 104
Table 57 – Signal characteristics . 106
Table C.1 – FatalError error numbers . 114
Table D.1 – Command codes for local bus data exchange . 115
Table D.2 – Command codes with DLMS and DLMS/COSEM . 116
Table H.1 – Discovery service . 121
Table H.2 – Service specification . 121

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICITY METERING DATA EXCHANGE –
THE DLMS/COSEM SUITE –
Part 3-1: Use of local area networks on twisted pair
with carrier signalling
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of 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, IEC publishes International Standards, Technical Specifications, Technical Reports,
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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. 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 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 IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62056-3-1 has been prepared by IEC technical committee 13:
Electrical energy measurement and control.
This second edition cancels and replaces the first edition of IEC 62056-3-1, issued in 2013, and
constitutes a technical revision.
The main technical changes with regard to the previous edition are as follows:
• addition of a profile which makes use of the IEC 62056 DLMS/COSEM Application layer and
COSEM object model;
• review of the data link layer which is split into two parts:
– a pure Data Link layer;
– a "Support Manager" entity managing the communication media;
• ability to negotiate the communication speed, bringing baud rate up to 9 600 bauds.

IEC 62056-3-1:2021 © IEC 2021 – 7 –
The text of this International Standard is based on the following documents:
CDV Report on voting
13/1794/CDV 13/1823/RVC
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts of IEC 62056 series, published under the general title Electricity metering data
exchange – The DLMS/COSEM suite, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

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ELECTRICITY METERING DATA EXCHANGE –
THE DLMS/COSEM SUITE –
Part 3-1: Use of local area networks on twisted pair
with carrier signalling
1 Scope
This part of IEC 62056 describes two sets of profiles: the first set of profiles allows a
bidirectional communication between a client and a server. This set of profiles is made of three
profiles allowing local bus data exchange with stations either energized or not. For non-
energized stations, the bus supplies energy for data exchange. Three different profiles are
supported:
• base profile: this three-layer profile provides remote communication services;
NOTE 1 This first profile was published in IEC 61142:1993 and became known as the Euridis standard.
• profile with DLMS: this profile allows using DLMS services as specified in IEC 61334-4-41;
NOTE 2 This second profile was published in IEC 62056-31:1999.
• profile with DLMS/COSEM: this profile allows using the DLMS/COSEM Application layer and
the COSEM object model as specified in IEC 62056-5-3 and in IEC 62056-6-2 respectively.
The three profiles use the same physical layer and they are fully compatible, meaning that
devices implementing any of these profiles can be operated on the same bus. The transmission
medium is twisted pair using carrier signalling and it is known as the Euridis Bus.
The second set of profiles allows unidirectional communication between a given Energy
Metering device and a Customer Energy Management System. This second set is made up of
three profiles.
Subclause 4.2.1 to Clause 8 included specify the bidirectional communication using twisted pair
signalling and Clause 9 to 9.5 the unidirectional communication using twisted pair signalling.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 61334-4-41:1996, Distribution automation using distribution line carrier systems – Part 4:
Data communication protocols – Section 41: Application protocols – Distribution line message
specification
IEC 62056-51:1998, Electricity metering – Data exchange for meter reading, tariff and load
control – Part 51: Application layer protocols
IEC 62056-5-3:2017, Electricity metering data exchange – The DLMS/COSEM suite – Part 5-3:
DLMS/COSEM application layer
IEC 62056-6-2:2017, Electricity metering data exchange – The DLMS/COSEM suite – Part 6-2:
COSEM interface classes
IEC 62056-3-1:2021 © IEC 2021 – 9 –
ISO/IEC 8482:1993, Information technology – Telecommunications and information exchange
between systems – Twisted pair multipoint interconnections
EIA 485, Standard for Electrical Characteristics of Generators and Receivers for Use in
Balanced Digital Multipoint Systems
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.2 Abbreviated terms
ADP Primary Station Address
ADG General Secondary Address. Broadcast Address
ADS Secondary Station Address
AGN Normal Wakeup
AGT General call for a General Energized Station
APDU Application Protocol Data Unit
APG General Primary Address
ARJ COM field value: Rejection of authentication in remote programming exchange
ASDU Application Service Data Unit
ASO COM field value: Call to Forgotten Stations
AUT COM field value: Authentication command
COM Control field of the Data Link layer
COSEM Companion Specification for Energy Metering
DAT COM field value: Response of remote reading exchange
DES Data Encryption Standard
DLMS Distribution Line Message Specification (IEC 61334-4-41)
Device Language Message Specification (IEC 62056-5-3)
DSDU Data link Service Data Unit
DRJ COM field value: Data Rejected
Value of COM notifying the rejection of remote programming exchange data
Dsap Transport data unit label. Coded over 3 bits. Its value is 6.
DTSAP Destination of Transport Service Access Point
ECH COM field value: Echo of remote programming exchange data
ENQ Remote reading exchange request
EOS COM field value: End of remote programming exchange
IB Initialisation of the bus
LDTI Local Data Transmission Interface
MaxRetry Maximum number retransmissions. Limited to 2.
MaxRSO Maximum number of RSO listening windows. Fixed at 3.

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PDU Protocol Data Unit
PRE COM field value: Pre-selection of energised stations
REC COM field value: Remote programming exchange request
RSO COM field value: Response to a call to forgotten stations
SEL COM field value: Acknowledgement of the pre-selection of energized stations
STSAP Source Transport Service Access Point
TAB In the case of the EURIDIS profiles without DLMS and without DLMS/COSEM: data code.
In the case of profiles using DLMS or DLMS/COSEM: value at which the equipment is
programmed for Discovery
TABi List of TAB field
TASB Duration of an Alarm Signal on the Bus
TIC Transmission of Information to the Customer
TOAG Maximum wait time for an energized station once selected, to recognise a general call AGN
TOALR Wait before sending an AGN after reception of an AGN or AGT
TOL Maximum waiting time for a request from the upper layer
TOPRE Maximum waiting time for a response to a pre-selection.
TOU Time of Use
TPDU Transport Protocol Data Unit
TSDU Transport Protocol Service Unit
TRA COM field value: Acknowledgement of point to point transfer
TRB COM field value: Broadcast remote transfer frame not acknowledged
TRF COM field value: Point to point remote transfer exchange
T1 Time out to wait for a response according to a request
XBA COM field value: Response to a change of speed request
XBR COM field value: Change of speed request
ZA1 Field reserved for bidirectional programming authentication
ZA2 Field reserved for bidirectional programming authentication

4 General description
4.1 Basic vocabulary
All communication calls upon two systems called Primary Station and Secondary Station. The
Primary Station is the system that decides to initialize a communication with a remote system
called Secondary Station; these designations remain valid throughout the duration of the
communication.
A communication is broken down into a certain number of transactions. Each transaction
consists of a transmission from the Transmitter to the Receiver. During the sequence of
transactions, the Primary Station and Secondary Station systems take turns to act as
Transmitter and Receiver.
For the local bus data exchange profile with DLMS or DLMS/COSEM, the terms Client and
Server have the same meaning as for the DLMS model (refer to IEC 61334-4-41 or
IEC 62056-5-3). The Server (which is a Secondary Station) receives and processes all
submissions of specific service requests. The Client (which is a Primary Station) is the system
that uses the Server for a specific purpose by means of one or more service requests.

IEC 62056-3-1:2021 © IEC 2021 – 11 –
4.2 Profiles, layers and protocols
4.2.1 Overview
This document specifies three profiles as shown in Figure 1.
• the base profile (without DLMS), see 4.2.2;
• the profile with DLMS, see 4.2.3;
• the profile with DLMS/COSEM; see 4.2.4.
The physical layer in the three profiles is the same except that in the DLMS/COSEM profile
speed negotiation is available. This common physical layer allows stations using different
profiles to be installed on the same bus.

Figure 1 – IEC 62056-3-1 communication profiles
4.2.2 Base profile (without DLMS)
The base profile (without DLMS) uses three protocol layers:
• the physical layer with the Physical-62056-3-1 protocol specified in 5.1;
• the data link layer with the Link-62056-3-1 protocol, specified in 5.2, and
• the application layer with the Application-62056-3-1 protocol specified in 5.3.

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This profile allows remote reading, remote programming, point-to-point remote transfer – which
is a simplified remote programming service – broadcast remote transfer, remote supply of
secondary stations, detecting forgotten stations and alarm functions. The related
communication services are specified in 4.4.
4.2.3 Profile with DLMS
The profile with DLMS uses three protocol layers:
• the same physical layer as the base profile, specified in 5.1;
• the data link layer using the Link-E/D protocol, specified in 6.2; and
• the application layer specified in IEC 62056-51, using the Transport+, Application+ and
DLMS+ protocols, see 6.3.
This profile also allows using DLMS as specified in IEC 61334-4-41. The related communication
services are specified in 4.5.
4.2.4 Profile with DLMS/COSEM
The profile with DLMS/COSEM uses four protocol layers:
• the physical layer, similar to the one used in the base profile and the profile with DLMS,
specified in 5.1, but with speed negotiation, see 7.2;
• the data link layer using the Link-E/D protocol. This is the same as the data link layer of the
profile with DLMS, except that it interfaces with the support manager layer and the transport
layer. See 7.3;
• the support manager layer supports some specific process for the management of the bus,
see 7.4;
• the transport layer provides segmentation and reassembly of APDUs, see 7.5;
• the application layer as specified in IEC 62056-5-3 taking into account some restrictions of
the Euridis bus, see 7.6.
The profile with DLMS/COSEM allows using the COSEM object model and the DLMS services
accessing the COSEM objects over the Euridis bus.
4.3 Specification language
In this document, the protocol of each layer is described by state transitions represented in the
form of tables. The syntax used in making up these tables is defined by a specification language
described in Annex A.
In the event of a difference in interpretation between part of the text and a state transition table,
the table is always taken as the reference.
4.4 Communication services for local bus data exchange without DLMS
4.4.1 Overview
The list of available services (see Annex I) at the Application level layer is:
a) remote reading of data, see 4.4.2;
b) remote programming of data, see 4.4.3;
c) point to point remote transfer, which is a simplified remote programming service, see 4.4.4;
d) broadcast remote transfer, 4.4.5;
e) bus initialization, 4.4.6;
f) forgotten station call, 4.4.7.

SIST EN IEC 62056
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