IEC 61158-4-3:2007 specifies the 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 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. It constitutes an editorial revision. It 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 (2014-08) corresponds to the English version, published in 2007-12.