IEC 61158-4-21:2023
Industrial communication networks - Fieldbus specifications - Part 4-21 : data-link layer protocol specification - Type 21 elements
IEC 61158-4-21:2023 describes: 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; procedures for giving communication opportunities based on ISO/IEC/IEEE 8802‑3 MAC, with provisions for nodes to be added or removed during normal operation; structure of the fieldbus data link protocol data units (DLPDUs) used for the transfer of data and control information by the protocol of this document, and their representation as physical interface data units.
IEC 61158-4-21:2023 describes:
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;
procedures for giving communication opportunities based on ISO/IEC/IEEE 8802‑3 MAC, with provisions for nodes to be added or removed during normal operation;
structure of the fieldbus data link protocol data units (DLPDUs) used for the transfer of data and control information by the protocol of this document, and their representation as physical interface data units.
IEC 61158-4-21:2019 describes 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 procedures for giving communication opportunities based on standard ISO/IEC 8802-3 MAC, with provisions for nodes to be added or removed during normal operation; structure of the fieldbus data link protocol data units (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 second edition cancels and replaces the first edition published in 2010. This edition constitutes a technical revision. The main changes are:<br /> • added Frame control Value, DLM function and DLL constants;<br /> • changed NCM_RETRY_RNMS to NCM_CHECK_NET_INTEGRITY_REQ;<br /> • updated DLM state table;<br /> • miscellaneous editorial corrections.
The Requirements department helps you quickly locate within the normative text:
- mandatory clauses to satisfy,
- non-essential but useful clauses to know, such as permissions and recommendations.
The identification of these types of clauses is based on the document “ISO / IEC Directives, Part 2 - Principles and rules of structure and drafting of ISO documents ”as well as on a constantly enriched list of verbal forms.
With Requirements, quickly access the main part of the normative text!
COBAZ is the simple and effective solution to meet the normative needs related to your activity, in France and abroad.
Available by subscription, CObaz is THE modular solution to compose according to your needs today and tomorrow. Quickly discover CObaz!
Request your free, no-obligation live demo
I discover COBAZ