BS EN 61158-3-3 is the third subpart of the third part of the multiple series that provides common elements for basic time-critical messaging communications between devices in an automation environment. The term “time-critical” is used to represent the presence of a time window, within which one or more specified actions are required to be completed with some defined level of certainty.
BS EN 61158-3-3 defines in an abstract way the externally visible service provided by the Type 3 Fieldbus data-link layer in terms of:
Note: Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life.
BS EN 61158-3-3 on data-link layer service definition is useful for:
BS EN 61158-3-3 defines the services provided to the Type 3 Fieldbus application layer at the boundary between the application and data-link layers of the Fieldbus reference model, and systems management at the boundary between the data-link layer and systems management of the Fieldbus reference model.
The principal objective of BS EN 61158-3-3 is to specify the characteristics of conceptual data-link layer services suitable for time-critical communications, and thus supplement the OSI Basic Reference Model in guiding the development of data-link protocols for time-critical communications.
A secondary objective is to provide migration paths from previously existing industrial communications protocols.
EN 61158-3-3:2014
EN 61558-2-20:2011
IEC 61158-3-3:2014
IEC 61558-2-20:2010