IEC 61158-4-19-ed.4.0

Annotation of standard text IEC 61158-4-19-ed.4.0 :

IEC 61158-4-19:2019 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 data-link service provider and 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. This fourth edition cancels and replaces the third edition published in 2014 and constitutes a technical revision. The main changes are: •improving the hotplug and redundancy features; •improving the phase switching and the error handling; •editorial improvements IEC 61158-4-19:2019 La couche liaison de donnees assure les communications de messagerie prioritaires de base entre les appareils d’un environnement d’automatisation. Ce protocole offre a toutes les entites de liaison de donnees participantes a) des opportunites de communication cyclique a demarrage synchrone, selon un ordre preetabli, et b) de maniere asynchrone cyclique ou acyclique, tel que requis a chaque cycle par chacune de ces entites de liaison de donnees. Ainsi, ce protocole peut etre caracterise comme un protocole qui offre un acces cyclique et acyclique asynchrone, mais avec un redemarrage synchrone de chaque cycle.