IEC 61158-4-12:2019

Industrial communication networks - Fieldbus specifications - Part 4-12: Data-link layer protocol specification - Type 12 elements

IEC 61158-4-12:2019 specifies procedures for the timely transfer of data and control information from one data-link user entity to a peer user entity, and among the data-link entities forming the distributed data-link service provider and the structure of the fieldbus DLPDUs used for the transfer of data and control information by the protocol of this standard, and their representation as physical interface data units. This fourth edition cancels and replaces the third edition published in 2014 and constitutes a technical revision. The main changes are: technical corrections and editorial improvements for clarification.

Réseaux de communication industriels - Spécifications des bus de terrain - Partie 4-12: Spécification du protocole de la couche liaison de données - Éléments de type 12

L'IEC 61158-4-12:2019 la couche de liaison de données assure les communications de messagerie à contrainte de temps de base entre les appareils d’un environnement d’automatisation.
Ce protocole offre des opportunités de communication à toutes les entités de liaison de données participantes
a) de manière cyclique et synchrone, et
b) de manière cyclique ou acyclique asynchrone, comme demandé par chaque cycle de chacune de ces entités de liaison de données.
Par conséquent, ce protocole peut se caractériser comme assurant un accès cyclique et acyclique asynchrone, mais avec un redémarrage synchrone de chaque cycle.

General Information

• Status: Published
• Publication Date: 17-Apr-2019
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 35.100.20 - Data link layer
• ICS: 35.110 - Networking
• Technical Committee: SC 65C - Industrial networks
• Drafting Committee: WG 9 - TC 65/SC 65C/WG 9
• Current Stage: PPUB - Publication issued
• Start Date: 26-Apr-2019
• Completion Date: 18-Apr-2019

Relations

• Revises: IEC 61158-4-12:2014 - Industrial communication networks - Fieldbus specifications - Part 4-12: Data-link layer protocol specification - Type 12 elements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61158-4-12 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
colour
inside
Industrial communication networks – Fieldbus specifications –
Part 4-12: Data-link layer protocol specification – Type 12 elements

All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
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About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

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IEC 61158-4-12 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
colour
inside
Industrial communication networks – Fieldbus specifications –

Part 4-12: Data-link layer protocol specification – Type 12 elements

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 25.040.40; 35.100.20; 35.110 ISBN 978-2-8322-6775-2

– 2 – IEC 61158-4-12:2019 © IEC 2019
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 11
1.1 General . 11
1.2 Specifications . 11
1.3 Procedures . 11
1.4 Applicability . 11
1.5 Conformance . 11
2 Normative references . 12
3 Terms, definitions, symbols, abbreviations and conventions . 12
3.1 Reference model terms and definitions . 12
3.2 Service convention terms and definitions . 13
3.3 Common terms and definitions . 14
3.4 Additional Type 12 definitions . 14
3.5 Common symbols and abbreviations . 17
3.6 Additional Type 12 symbols and abbreviations . 18
3.7 Conventions . 19
3.7.1 General concept . 19
3.7.2 Abstract syntax conventions . 19
3.7.3 Convention for the encoding of reserved bits and octets . 21
3.7.4 Conventions for the common coding s of specific field octets . 21
3.7.5 State machine conventions . 22
4 Overview of the DL-protocol . 24
4.1 Operating principle. 24
4.2 Topology . 24
4.3 Frame processing principles . 24
4.4 Data-link layer overview . 25
4.5 Error detection overview . 26
4.6 Node reference model . 26
4.6.1 Mapping onto OSI basic reference model . 26
4.6.2 Data-link Layer features . 27
4.7 Operation overview . 27
4.7.1 Relation to ISO/IEC/IEEE 8802-3 . 27
4.7.2 Frame structure . 27
5 Frame structure . 28
5.1 Frame coding principles . 28
5.2 Data types and encoding rules . 28
5.2.1 General description of data types and encoding rules . 28
5.2.2 Transfer syntax for bit sequences . 28
5.2.3 Unsigned Integer . 29
5.2.4 Signed Integer . 30
5.2.5 Octet String . 30
5.2.6 Visible String . 30
5.3 Ethernet DLPDU structure . 31
5.3.1 Type 12 frame inside an Ethernet frame . 31
5.3.2 Type 12 frame inside a UDP datagram . 31

5.3.3 Type 12 frame structure . 33
5.4 Type 12 DLPDU structure . 33
5.4.1 Read . 33
5.4.2 Write . 38
5.4.3 Read write . 43
5.4.4 Attributes access . 50
5.5 Network variable structure . 50
5.6 Type 12 mailbox structure . 51
6 Attributes . 52
6.1 Management . 52
6.1.1 DL Information . 52
6.1.2 Station address . 56
6.1.3 DL control . 57
6.1.4 DL status . 59
6.1.5 DLS-user specific registers . 62
6.1.6 Event parameter . 63
6.2 Statistics . 68
6.2.1 RX error counter . 68
6.2.2 Lost link counter . 69
6.2.3 Additional counter . 70
6.3 Watchdogs . 71
6.3.1 Watchdog divider . 71
6.3.2 DLS-user watchdog . 72
6.3.3 Sync manager watchdog . 72
6.3.4 Sync manager watchdog status . 73
6.3.5 Watchdog counter. 74
6.4 Slave information interface . 74
6.4.1 Slave information interface area . 74
6.4.2 Slave information interface access . 74
6.4.3 Slave information interface control/status . 75
6.4.4 Slave information interface address . 77
6.4.5 Slave information interface data . 78
6.5 Media independent interface (MII) . 78
6.5.1 MII control/status . 78
6.5.2 MII address . 80
6.5.3 MII data . 81
6.5.4 MII access . 81
6.6 Fieldbus memory management unit (FMMU) . 82
6.6.1 General . 82
6.6.2 FMMU attributes . 83
6.7 Sync manager . 85
6.7.1 Sync manager overview . 85
6.7.2 Sync Manager Attributes . 88
6.8 Distributed clock . 91
6.8.1 General . 91
6.8.2 Delay measurement . 91
6.8.3 Local time parameter . 92
6.8.4 DL-user time parameter . 92
6.8.5 DC attributes . 93

– 4 – IEC 61158-
...

IEC 61158-4-12 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Fieldbus specifications –
Part 4-12: Data-link layer protocol specification – Type 12 elements

Réseaux de communication industriels – Spécifications des bus de terrain –
Partie 4-12: Spécification du protocole de la couche liaison de données –
Éléments de type 12
All rights reserved. Unless otherwise specified, 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
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

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3, rue de Varembé [e-mail]
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: [e-mail].
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IEC 61158-4-12 ®
Edition 4.0 2019-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Industrial communication networks – Fieldbus specifications –

Part 4-12: Data-link layer protocol specification – Type 12 elements

Réseaux de communication industriels – Spécifications des bus de terrain –

Partie 4-12: Spécification du protocole de la couche liaison de données –

Éléments de type 12
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.040.40; 35.100.20; 35.110 ISBN 978-2-8322-9141-2

– 2 – IEC 61158-4-12:2019 © IEC 2019
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 11
1.1 General . 11
1.2 Specifications . 11
1.3 Procedures . 11
1.4 Applicability . 11
1.5 Conformance . 11
2 Normative references . 12
3 Terms, definitions, symbols, abbreviations and conventions . 12
3.1 Reference model terms and definitions . 12
3.2 Service convention terms and definitions . 13
3.3 Common terms and definitions . 14
3.4 Additional Type 12 definitions . 14
3.5 Common symbols and abbreviations . 17
3.6 Additional Type 12 symbols and abbreviations . 18
3.7 Conventions . 19
3.7.1 General concept . 19
3.7.2 Abstract syntax conventions . 19
3.7.3 Convention for the encoding of reserved bits and octets . 21
3.7.4 Conventions for the common coding s of specific field octets . 21
3.7.5 State machine conventions . 22
4 Overview of the DL-protocol . 24
4.1 Operating principle. 24
4.2 Topology . 24
4.3 Frame processing principles . 24
4.4 Data-link layer overview . 25
4.5 Error detection overview . 26
4.6 Node reference model . 26
4.6.1 Mapping onto OSI basic reference model . 26
4.6.2 Data-link Layer features . 27
4.7 Operation overview . 27
4.7.1 Relation to ISO/IEC/IEEE 8802-3 . 27
4.7.2 Frame structure . 27
5 Frame structure . 28
5.1 Frame coding principles . 28
5.2 Data types and encoding rules . 28
5.2.1 General description of data types and encoding rules . 28
5.2.2 Transfer syntax for bit sequences . 28
5.2.3 Unsigned Integer . 29
5.2.4 Signed Integer . 30
5.2.5 Octet String . 30
5.2.6 Visible String . 30
5.3 Ethernet DLPDU structure . 31
5.3.1 Type 12 frame inside an Ethernet frame . 31
5.3.2 Type 12 frame inside a UDP datagram . 31

5.3.3 Type 12 frame structure . 33
5.4 Type 12 DLPDU structure . 33
5.4.1 Read . 33
5.4.2 Write . 38
5.4.3 Read write . 43
5.4.4 Attributes access . 50
5.5 Network variable structure . 50
5.6 Type 12 mailbox structure . 51
6 Attributes . 52
6.1 Management . 52
6.1.1 DL Information . 52
6.1.2 Station address . 56
6.1.3 DL control . 57
6.1.4 DL status . 59
6.1.5 DLS-user specific registers . 62
6.1.6 Event parameter . 63
6.2 Statistics . 68
6.2.1 RX error counter . 68
6.2.2 Lost link counter . 69
6.2.3 Additional counter . 70
6.3 Watchdogs . 71
6.3.1 Watchdog divider . 71
6.3.2 DLS-user watchdog . 72
6.3.3 Sync manager watchdog . 72
6.3.4 Sync manager watchdog status .
...