What is BS EN 61158-4-18 - Data-link layer protocol specification of type 18 elements about?
BS EN 61158-4-18 is the 18th subpart of the fourth part of multiple series that 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, according to a pre-established schedule
- In a cyclic or acyclic asynchronous manner, as requested each cycle by each of those data-link entities
Thus, this protocol can be characterized as one which provides cyclic and acyclic access asynchronously but with a synchronous restart of each cycle.
Note 1: BS EN 61158-4-18 does not specify individual implementations or products, nor do they constrain the implementations of data-link entities within industrial automation systems.
Note 2: There is no conformance of equipment to this data-link layer service definition standard. Instead, conformance is achieved through the implementation of the corresponding data-link protocol that fulfils the Type 18 data-link layer services defined in BS EN 61158-4-18.
Who is BS EN 61158-4-18 - Data-link layer protocol specification of type 18 elements for?
BS EN 61158-4-18 on Data-link layer protocol specification of type 18 elements is useful for:
- Small scale automation industries
- Large scale automation industries
- Network controlling companies
- Transport companies
Why should you use BS EN 61158-4-18 - Data-link layer protocol specification of type 18 elements?
BS EN 61158-4-18 facilitates the interconnection of automation system components. BS EN 61158-4-18 is related to other standards in the set as defined by the “three-layer” Fieldbus reference model described in IEC 61158-1.
BS EN 61158-4-18 assists you with:
- Procedures for the timely transfer of data and control information from one data-link and among the data-link entities forming the distributed datalink service provider
- Procedures for giving communications opportunities to all participating dl-entities, sequentially and in a cyclic manner for deterministic and synchronized transfer at cyclic intervals up to one millisecond
- Procedures for giving communication opportunities available for time-critical data transmission together with non-time-critical data transmission without prejudice to the time-critical data transmission
- Procedures for giving cyclic and acyclic communication opportunities for time-critical data transmission with prioritized access
- Procedures for giving communication opportunities based on standard iso/ IEC 8802-3 medium access control, with provisions for nodes to be added or removed during normal operation
- The structure of the Fieldbus DLPDUs used for the transfer of data and control information by the protocol of this standard, and their representation as physical interface data units
Overall, BS EN 61158-4-18 provides interactions between peer DL-entities (DLEs) through the exchange of fieldbus DLPDUs
What’s changed since the last update?
BS EN 61158-4-18:2012 supersedes BS EN 61158-4-18:2008 which is withdrawn.
EN 61158-4-18:2012 includes the following significant technical changes with respect to EN 61158-4-18:2008:
- Editorial improvements
- The addition of cyclic data segmenting
