IEC 61158-4-18-ed.2.0

Annotation of standard text IEC 61158-4-18-ed.2.0 :

IEC 61158-4-18:2010 specifies the protocol which provides communication opportunities to all participating data-link entities in a synchronously-starting cyclic manner, according to a pre-established schedule, and in a cyclic or acyclic asynchronous manner, as requested each cycle by each of those data-link entities. The described procedures are applicable to instances of communication between systems which support time-critical communications services within the data-link layer of the OSI or fieldbus reference models, and which require the ability to interconnect in an open systems interconnection environment. Profiles provide a simple multi-attribute means of summarizing an implementations capabilities, and thus its applicability to various time-critical communications needs. This bilingual version (2012-08) corresponds to the monolingual English version, published in 2010-08. This second edition cancels and replaces the first edition published in 2007 and constitutes a technical revision. The main changes with respect to the previous edition are: Editorial improvements and Addition of cyclic data segmenting. La CEI 61158-4-18:2010 specifie un protocole qui offre a toutes les entites de liaison de donnees participantes des opportunites de communiquer de maniere cyclique a demarrage synchrone, selon un ordre preetabli, et de maniere asynchrone cyclique ou acyclique, tel que requis par chaque cycle de chacune de ces entites de liaison de donnees. Les procedures decrites sappliquent aux instances de communication entre des systemes qui prennent en charge des services de communications a contrainte de temps dans la couche de liaison de donnees des modeles de reference OSI ou de bus de terrain, et qui peuvent etre connectes dans un environnement dinterconnexion de systemes ouverts. Les profils sont un moyen simple a plusieurs attributs de recapituler les capacites dune mise en uvre, et donc son applicabilite en fonction des differents besoins de communications a contrainte de temps. Cette seconde edition annule et remplace la premiere edition parue en 2007. Elle constitue une revision technique. Les principales modifications par rapport a ledition precedente sont: Ameliorations redactionnelles et Ajout dune segmentation des donnees cycliques. La presente version bilingue (2012-08) correspond a la version anglaise monolingue publiee en 2010-08.