What is IEC 61158-3-4 - data-link layer about?
IEC 61158-3-4 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. 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.
IEC 61158-3-4 defines in an abstract way the externally visible services provided by the Type 4 Fieldbus data-link layer in terms of:
- The primitive actions and events of the services
- The parameters associated with each primitive action and event, and the form in which they take
- The interrelationship between these actions and events, and their valid sequences
The purpose of IEC 61158-3-4 is to define the services provided to:
- The Type 4 Fieldbus application layer at the boundary between the application and data-link
layers of the Fieldbus reference model
- Systems management at the boundary between the data-link layer and systems management of the Fieldbus reference model
Who is IEC 61158-3-4 - data-link layer for?
IEC 61158-3-4 on data-link layer service definition is useful for:
- Small scale automation industries
- Large scale automation industries
- Network controlling companies
- Transport companies
Why should you use IEC 61158-3-4 - data-link layer?
IEC 61158-3-4 is part of the industrial communication network series that has been produced to facilitate the interconnection of automation system components.
The principal objective of IEC 61158-3-4 is to provide the characteristics of conceptual datalink
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 to users.
What’s changed since the last update?
BS EN IEC 61158-3-4:2019 supersedes BS EN 61158-3-4:2014. BS EN IEC 61158-3-4:2019 includes some technical changes with respect to BS EN 61158-3-4:2014. These include:
- Additional user parameters to services
- Additional services to support distributed objects
- Additional secure services