IEC 61588:2009

Precision clock synchronization protocol for networked measurement and control systems

IEC 61588:2009(E) defines a protocol enabling precise synchronization of clocks in measurement and control systems implemented with technologies such as network communication, local computing, and distributed objects. The protocol is applicable to systems communicating by local area networks supporting multicast messaging including, but not limited to, Ethernet. The protocol enables heterogeneous systems that include clocks of various inherent precision, resolution, and stability to synchronize to a grandmaster clock. The protocol supports system-wide synchronization accuracy in the sub-microsecond range with minimal network and local clock computing resources. The default behavior of the protocol allows simple systems to be installed and operated without requiring the administrative attention of users. The standard includes mappings to User Datagram Protocol (UDP)/Internet Protocol (IP), DeviceNet, and a layer-2 Ethernet implementation. It includes formal mechanisms for message extensions, higher sampling rates, correction for asymmetry, a clock type to reduce error accumulation in large topologies, and specifications on how to incorporate the resulting additional data into the synchronization protocol. This second edition cancels and replaces the first edition published in 2004. It constitutes a technical revision.

General Information

• Status: Published
• Publication Date: 26-Feb-2009
• ICS: 25.040.40 - Industrial process measurement and control
• ICS: 31.200 - Integrated circuits. Microelectronics
• ICS: 35.110 - Networking
• ICS: 35.240.50 - IT applications in industry
• Technical Committee: SC 65C - Industrial networks
• Current Stage: DELPUB - Deleted Publication
• Completion Date: 08-Jun-2021

Relations

• Revises: IEC 61588:2004 - Precision clock synchronization protocol for networked measurement and control systems
• Effective Date: 05-Sep-2023
• Revised: IEC 61588:2021 - Precision Clock Synchronization Protocol for Networked Measurement and Control Systems
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61588
Edition 2.0 2009-02
™
IEEE 1588
INTERNATIONAL
STANDARD
Precision clock synchronization protocol for networked measurement and
control systems
All rights reserved. IEEE is a registered trademark in the U.S. Patent & Trademark Office, owned by the Institute of
Electrical and Electronics Engineers, Inc.
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 the IEC Central Office.
Any questions about IEEE copyright should be addressed to the IEEE. Enquiries about obtaining additional rights
to this publication and other information requests should be addressed to the IEC or your local IEC member National
Committee.
IEC Central Office The Institute of Electrical and Electronics Engineers, Inc
3, rue de Varembé 3 Park Avenue
CH-1211 Geneva 20 US-New York, NY10016-5997
Switzerland USA
Email: [e-mail] Email: [e-mail]
Web: www.iec.ch Web: www.ieee.org

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 corrigenda or an amendment might have been published.
ƒ Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
ƒ IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
ƒ Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
ƒ Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: [e-mail]
Tel.: [phone]
IEC 61588
Edition 2.0 2009-02
IEEE 1588™
INTERNATIONAL
STANDARD
Precision clock synchronization protocol for networked measurement and

control systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
XH
ICS 25.040.40; 35.110; 35.240.50 ISBN 978-2-88910-546-5

– i – IEC 61588:2009(E)
IEEE 1588-2008(E)
CONTENTS
Foreword.xi
IEEE introduction. xiv
1. Overview . 1
1.1 Scope . 1
1.2 Purpose . 2
1.3 Layout of the document. 2
2. Normative references. 3
3. Definitions, acronyms, and abbreviations . 4
3.1 Definitions . 4
3.2 Acronyms and abbreviations . 7
4. Conventions. 8
4.1 Descriptive lexical form syntax . 8
4.2 Word usage. 9
4.3 Behavioral specification notation . 10
5. Data types and on-the-wire formats in a PTP system. 11
5.1 General . 11
5.2 Primitive data type specifications. 11
5.3 Derived data type specifications. 12
5.4 On-the-wire formats . 15
6. Clock synchronization model . 16
6.1 General . 16
6.2 Principle assumptions about the network and implementation recommendations. 16
6.3 PTP systems. 17
6.4 PTP message classes. 17
6.5 PTP device types . 18
6.6 Synchronization overview . 29
6.7 PTP communications overview . 37
7. Characterization of PTP entities . 41
7.1 Domains. 41
7.2 PTP timescale . 41
7.3 PTP communications. 42
7.4 PTP communication media. 46
7.5 PTP ports . 47
7.6 PTP device characterization . 53
7.7 PTP timing characterization . 61
8. PTP data sets . 63
8.1 General specifications for data set members . 63
8.2 Data sets for ordinary and boundary clocks. 65
8.3 Data sets for transparent clocks . 74
9. PTP for ordinary and boundary clocks . 76
9.1 General protocol requirements for PTP ordinary and boundary clocks. 76
9.2 State protocol. 76
9.3 Best master clock algorithm . 83
9.4 Grandmaster clocks . 92
9.5 Message processing semantics . 93
9.6 Changes in the local clock . 107
10. PTP for transparent clocks. 107
10.1 General requirements for both end-to-end and peer-to-peer transparent clocks . 107
10.2 End-to-end transparent clock requirements . 108
Published by IEC under licence from IEEE. © 2008 IEEE. All rights reserved.

IEEE 1588-2008(E)
10.3 Peer-to-peer transparent clock requirements. 108
11. Clock offset, path delay, residence time, and asymmetry corrections. 108
11.1 General specifications. 108
11.2 Computation of clock offset in ordinary and boundary clocks. 109
11.3 Delay request-response mechanism. 110
11.4 Peer delay mechanism . 112
11.5 Transparent clock residence time correction for PTP version 2 events . 117
11.6 Asymmetry correction for PTP version 2 event messages. 120
12. Synchronization and syntonization of clocks . 122
12.1 Syntonization. 122
12.2 Synchronization. 123
13. PTP message formats . 124
13.1 General . 124
13.2 General message format requirements. 124
13.3 Header. 124
13.4 Suffix . 128
13.5 Announce message . 128
13.6 Sync and Delay_Req messages. 130
13.7 Follow_Up message . 130
13.8 Delay_Resp message . 130
13.9 Pdelay_Req message . 131
13.10 Pdelay_Resp message. 131
13.11 Pdelay_Resp_Follow_Up message. 132
13.12 Signaling message . 132
13.13 Management message. 133
14. TLV entity specifications . 133
14.1 General requirements. 133
14.2 Experimental TLVs . 134
14.3 Vendor and standard organization extension TLVs. 135
15. Management .
...