BS EN 61158-4-14:2008

IEC 61158-4-14:2007 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;
- procedures for giving communications opportunities to all participating DL entities, sequentially and in a cyclic manner for deterministic and synchronized transfer at cyclic intervals up to one millisecond;
- procedures for giving communication opportunities available for time-critical data transmission together with non-time-critical data transmission without prejudice to the time-critical data transmission;
- procedures for giving cyclic and acyclic communication opportunities for time-critical data transmission with prioritized access;
- procedures for giving communication opportunities based on standard ISO/IEC 8802-3 medium access control, with provisions for nodes to be added or removed during normal operation;
- 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 first edition and its companion parts of the IEC 61158-4 subseries cancel and replace IEC 61158-4:2003 and constitutes a technical addition. This part and its Type 14 companion parts also cancel and replace IEC/PAS 62409, published in 2005. This edition includes the following changes:
- deletion of the former Type 6 fieldbus, and the placeholder for a Type 5 fieldbus data link layer, for lack of market relevance;
- addition of new types of fieldbuses;
- division of this part into multiple parts numbered -4 1, -4 2, , -4-19. This bilingual version (2015-06) corresponds to the English version, published in 2007-12.