TE( ISO SO/IEC18012-4 Edition 1.0 2025-07 INTERNATIONAL STANDARD interoperability - Part 4: Event encoding ISO/IEC 18012-4: 2025-07(en) ICS 35.200 ISBN 978-2-8327-0551-3 THIS PUBLICATIONIS COPYRIGHTPROTECTED Copyright2025ISO/IEC,Geneva,Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or 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. IEC Secretariat Tel.: +41 22 919 02 11 3, rue de Varembe [email protected] CH-1211Geneva 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. AboutIECpublications 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. IECpublicationssearch- IEC Products&Services Portal-products.iec.ch webstore.iec.ch/advsearchform Discover our powerful search engine and read freely all the The advanced search enables to find IEC publications by a publications previews, graphical symbols and the glossary. With variety of criteria(referencenumber,text,technical a subscription youwill always have access to up to date content committee, ...). It also gives information on projects, replaced tailored to your needs and withdrawn publications. Electropedia-www.electropedia.org IECJustPublished-webstore.iec.ch/justpublished The world's leading online dictionary on electrotechnology. Stay up to date on all new IEC publications. Just Published containing more than 22 500 terminological entries in English details all new publications released. Available online and and French, with equivalent terms in 25 additional languages once a month by email. Also known as the International Electrotechnical Vocabulary (IEV) online IEC Customer Service Centre -webstore.iec.ch/csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre:[email protected]. Warning!Makesurethatyouobtained thispublicationfromanauthorizeddistributor. ISO/IEC18012-4:2025@ISO/IEC2025 CONTENTS FOREWORD INTRODUCTION. 5 0.1 Overview 0.2 Relation to existing work 5 0.3 Lexicon and event encoding 6 1 Scope....... 2 Normativereferences. .8 3 Terms, definitions and abbreviated terms. 3.1 Terms and definitions. 3.2 Abbreviated terms.. .10 4 Conformance requirements... .10 5 HEScommonlanguagemessageexchange(HES-CLME). 5.1 HES gateway system ..... 11 5.2 HES - common language internal protocol (HES-CLIP)... 5.2.1 HES-CLIP summary.... ..12 5.2.2 Requirementsforthe IP network .13 5.2.3 Discovery requirements for all devices... 5.2.4 Requirementsforlowerlayercommunicationsforall devices... 5.2.5 Packet structure.... .15 5.2.6 Operations and communication methods 17 5.2.7 Overall CoAP model... 5.2.8 Client requirements.. .19 5.2.9 Server requirements.. .23 5.3 HES-commonlanguagedirectPDUexchange (HES-CLDPE). ..28 5.3.1 Overview. .28 5.3.2 HES-commonlanguagedirectPDUexchange(HES-CLDPE/G). ...28 AnnexA(normative)Packet construction A.1 Packetconstructionoverview. ...31 A.2 Packet type: Lexicon representation (lx'). .32 A.2.1 General A.2.2 Lexicon type: Lexicon representation (ob'). A.2.3 Lexicontype:Actions(ac').. A.3 Packettype:Othertypes of packet. .34 AnnexB(informative)Example of packet exchange. .35 B.1 Example setup. ....35 B.2 Example operation. ...36 B.3 Timeflow diagram and PDU construction forexample.. ..37 Bibliography Figure 1-ISO/lEC 18012-4 within the core interoperabilityandHESgateway standards.. .7 Figure 2-Communications for the HES gateway system Figure3-Communicati