IEC 61158-5-8:2007 specifies the structure and services of the Type 8 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498) and the OSI application layer structure (ISO/IEC 9545).This first edition and its companion parts of the IEC 61158-5 subseries cancel and replace IEC 61158-5:2003. This edition of this part constitutes a technical revision and includes the following changes: - deletion of the former Type 6 fieldbus for lack of market relevance; - addition of new types of fieldbuses; - partition of part 5 of the third edition into multiple parts numbered -5-2, -5-3,. This bilingual version (2015-06) corresponds to the English version, published in 2007-12.