IEC 61158-4-7:2007

FOREWORD
INTRODUCTION
1 Scope
2 Normative references
3 Terms, definitions, symbols and abbreviations
4 Overview of the DL-protocol
5 General structure and encoding of PhIDUs and DLPDUs
  and related elements of procedure
6 DLPDU-specific structure, encoding and element of
  procedure
7 DL-service elements of procedure, interfaces and
  conformance
Annex A (informative) - Exemplary FCS implementation
Annex B (informative) - Object modeling
Annex C (informative) - Topology of multi-segment
        DL-subnetwork
Annex D (informative) - Management of transmission errors
Bibliography

IEC 61158-4-7:2007 describes the data-link layer which provides basic time-critical messaging communications between devices in an automation environment. It specifies the 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. This first edition and its companion parts of the IEC 61158-4 subseries cancel and replace IEC 61158-4:2003 and constitutes an editorial revision. It includes the following changes:
- deletion of the former Type 6 fieldbus, and the placeholder for a Type 5 fieldbus data link layer, for lack of market relevance;
- addition of new types of fieldbuses;
- division of this part into multiple parts numbered -4 1, -4 2,..., -4-19. This bilingual version (2013-09) corresponds to the monolingual English version, published in 2007-12.