IEC 61158-6-7:2007 describes the fieldbus application layer (FAL) which provides user programs with a means to access the fieldbus communication environment. In this respect, the FAL can be viewed as a "window between corresponding application programs." It specifies the protocol of the Type 7 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 61158-6 subseries cancel and replace IEC 61158-6:2003. It 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 6 of the third edition into multiple parts numbered -6 2, -6 3,.... This bilingual version (2013-09) corresponds to the monolingual English version, published in 2007-12.