Specifies interactions between remote applications in terms of: - the encoding rules that are applied to all the Application Layer Protocol Data Units (APDUs); - the formal Abstract Syntax defintiions of such APDUs; - the protocol state machine descriptions that handle the APDUs and the primitives int he correct sequence; - the mappings of the APDUs to and from the Data Link Layer services defined in IEC 61158-3. Defines the protocol provided: a) to the Fieldbus Data Link Layer at the boundary between the Application and Data Link Layers of the Fieldbus Reference Model, and b) to the System Management at the boundary between the System Management and Application Layers of the Fieldbus Reference Model.