What is BS EN IEC 61158-4-12 - Fieldbus specifications about?
The data-link layer provides basic time-critical messaging communications between devices in an automation environment.
This protocol provides communication opportunities to all participating data-link entities
- In a synchronously-starting cyclic manner, and
- In a cyclic or acyclic asynchronous manner, as requested each cycle by each of those data-link entities
BS EN IEC 61158-4-12 can be characterized as one which provides cyclic and acyclic access asynchronously but with a synchronous restart of each cycle.
BS EN IEC 61158-4-12 specifies
- Procedures for the transfer of data and control information from one data-link user entity to one or more user entity
- The structure of the DLPDUs used for the transfer of data and control information by the protocol of this document, and their representation as physical interface data units
NOTE: The use of some of the associated protocol types is restricted by their intellectual property-right holders. In all cases, the commitment to the limited release of intellectual property rights made by the holders of those rights permits a particular data-link layer protocol type to be used with physical layer and application layer protocols in Type combinations as specified explicitly in the profile parts. Use of the various protocol types in other combinations may require permission from their respective intellectual property-right holders.
Who is BS EN IEC 61158-4-12 - Fieldbus specifications for?
BS EN IEC 61158-4-12 on Fieldbus specifications is useful for:
- The IT industry / Software programmers
- Internet engineering task forces
- The automation industry
- Internet service providers
- The telecommunication industry
Why should you use BS EN IEC 61158-4-12 - Fieldbus specifications?
BS EN IEC 61158-4-12 is one of a series produced to facilitate the interconnection of automation system components. It is related to other standards in the set as defined by the “three-layer” fieldbus reference model described in IEC 61158-1.
The data-link protocol provides the data-link service by making use of the services available from the physical layer. The primary aim of BS EN IEC 61158-4-12 is to provide a set of rules for communication expressed in terms of the procedures to be carried out by peer data-link entities (DLEs) at the time of communication. These rules for communication are intended to provide a sound basis for development in order to serve a variety of purposes:
- As a guide for implementers and designers
- For use in the testing and procurement of equipment
- As part of an agreement for the admittance of systems into the open systems environment
- As a refinement to the understanding of time-critical communications within OSI
What’s changed since the last update?
BS EN IEC 61158-4-12 supersedes EN 61158-4-12:2014, which is withdrawn. BS EN IEC 61158-4-12 includes some technical changes with respect to EN 61158-4-12:2014. These includes:
- Technical corrections and editorial improvements for clarification

