EN 61158-4-21:2012

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms, definitions, symbols and abbreviations
4 Overview of the data-link protocol
5 General structure and encoding
6 DLPDU structure and procedure
7 DLE elements of procedure
8 Constants and error codes
Bibliography
Annex ZA (normative) - Normative references to international
         publications with their corresponding European
         publications

IEC 61158-4-21:2010 describes 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 procedures for giving communication opportunities based on standard ISO/IEC 8802-3 MAC, with provisions for nodes to be added or removed during normal operation; structure of the fieldbus data link protocol data units (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 standard cancels and replaces IEC/PAS 62573 published in 2008. This bilingual version published in 2012-01 corresponds to the English version published in 2010-08.