IEC 61158-6-12 Ed. 4.0 en:2019

IEC 61158-6-12:2019(E) defines the protocol provided to define the wire-representation of the service primitives defined in IEC 61158-5-12, and define the externally visible behavior associated with their transfer. This standard specifies the protocol of the Type 12 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545).