EN 61158-4-21 : 2012被替代
INDUSTRIAL COMMUNICATION NETWORKS - FIELDBUS SPECIFICATIONS - PART 4-21: DATA-LINK LAYER PROTOCOL SPECIFICATION - TYPE 21 ELEMENTS (IEC 61158-4-21:2010)
出版：European Committee for Standards - Electrical
专家解读视频
Explains: a) 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; b) 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; and c) 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.
