IEC 61158-6-21 Ed. 1.0 en:2010

IEC 61158-6-21:2010(E) specifies the protocol of the Type 21 fieldbus application layer, in conformance with the OSI Basic Reference Model (ISO/IEC 7498-1) and the OSI application layer structure (ISO/IEC 9545). It defines the protocol provided to define the wire-representation of the service primitives defined in IEC 61158-5-21:2010, and the externally visible behavior associated with their transfer. This standard cancels and replaces IEC/PAS 62573 published in 2008.