BS EN 61158-3-11 is the 11th subpart of the third part of the multiple series standard 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 61158-3-11 defines in an abstract way the externally visible service provided by the Type 11 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 61158-3-11 on data-link layer service definition is useful for:
DL-segment, the local link is a set of devices that respect the DL protocol and that are interconnected through a PhL. Only one bus arbitrator is active on a single DL-segment.
BS EN 61158-3-11 defines the services provided to the Type 11 Fieldbus application layer at the boundary between the application and datalink 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 61158-3-11 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.
BS EN 61158-3-11:2008 supersedes BS EN 61158-3:2004 which is withdrawn.
With respect to EN 61158-3:2004 the following changes were made:
EN 61158-3-11:2008
IEC 61158-3-11:2007