BS EN 61158-5-18:2012 PDF

What is BS EN 61158-5-18 - Type 18 application layer service definition about?

BS EN 61158-5-18 is part of a series produced to facilitate the interconnection of automation system components. BS EN 61158-5-18 is related to other standards in the set as defined by the “three-layer” fieldbus reference model described in IEC/TR 61158-1 . BS EN 61158-5-18 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 18 fieldbus. 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. 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 61158-5-18 defines in an abstract way the externally visible service provided by the Type 18 fieldbus application layer in terms of:

An abstract model for defining application resources (objects) capable of being manipulated by users via the use of the FAL service The primitive actions and events of the service The parameters associated with each primitive action and event, ...