IEC/PAS 61158-6-22:2009(E) provides common elements for basic time-critical and non-time-critical messaging communications between application programs in an automation environment and material specific to Type SNpTYPE fieldbus. It defines in an abstract way the externally visible behavior provided by the different Types of the fieldbus Application Layer in terms of:
- the abstract syntax;
- the transfer syntax;
- the application context state machine and the application relationship state machines.
The purpose of this PAS is to define the protocol provided to:
- define the wire-representation of the service primitives defined in IEC/PAS 61158 5 22;
- and define the externally visible behavior associated with their transfer. It contains an additional profile - SNpTYPE - which may be integrated into a future new edition of the IEC 61158-6 series.