What is BS EN IEC 61158-4-3 - Data link layer protocol type 3 about?
BS EN IEC 61158-4-3 is part of the BS EN IEC 61158 series that has been created to facilitate the interconnection of automation system components. The data-link layer provides basic time-critical messaging communications between devices in an automation environment.
BS EN IEC 61158-4-3 provides communication opportunities to a pre-selected “master” subset of datalink entities in a cyclic asynchronous manner, sequentially to each of those data-link entities. Other data-link entities communicate only as permitted and delegated by those master datalink entities. For a given master, its communications with other data-link entities can be cyclic, acyclic with prioritized access, or a combination of the two.
BS EN IEC 61158-4-3 provides a means of sharing the available communication resources in a fair manner. There are provisions for time synchronization and for isochronous operation. BS EN IEC 61158-4-3 specifies:
- Procedures for the timely transfer of data and control information from one data-link user entity to a peer user entity, and among the data-link entities forming the distributed datalink service provider
- The structure of the Fieldbus DLPDUs used for the transfer of data and control information by the protocol of this document, and their representation as physical interface data units
Who is BS EN IEC 61158-4-3 - Data link layer protocol type 3 for?
BS EN IEC 61158-4-3 on data link layer protocol type 3 elements is useful for:
- The IT industry / Software programmers
- Internet engineering task forces
- The automation industry
- Networking sectors
- Implementors and designers of industrial automation systems
Why should you use BS EN IEC 61158-4-3 - Data link layer protocol type 3?
BS EN IEC 61158-4-3 was 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. BS EN IEC 61158-4-3 provides 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 implementors 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
BS EN IEC 61158-4-3 is concerned with the communication and interworking of sensors, effectors, and other automation devices. By using BS EN IEC 61158-4-3 together with other standards positioned within the OSI or fieldbus reference models, otherwise incompatible systems may work together in any combination. Using BS EN IEC 61158-4-3 guidelines, you are in a position to facilitate industrial automation that accelerates productivity.
What’s changed since the last update?
BS EN IEC 61158-4-3:2019 supersedes BS EN 61158-4-3:2014, which will be withdrawn on 23 May 2022 and is identical to BS EN IEC 61158-4-3:2019. The technical changes as compared to the third edition published in 2014 are:
- Corrections in Table 3
- Corrections in Table A.15
- Spelling and grammar

