IEC 61158-6-4:2007 defines the protocol provided to define the wire-representation of the service primitives defined in IEC 61158-5-4, and define the externally visible behaviour associated with their transfer. This standard specifies the protocol of the Type 4 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. This edition of this part constitutes a technical addition. This part and its Type 4 companion parts also cancel and replace IEC/PAS 62412, published in 2005. This edition of IEC 61158-6 includes the following significant changes from the previous edition: - 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 (2014-12) corresponds to the monolingual English version, published in 2007-12.