EN 61158-3-8:2008

INTRODUCTION
1 Scope
  1.1 Overview
  1.2 Specifications
  1.3 Conformance
2 Normative references
3 Terms, definitions, symbols, abbreviations and conventions
  3.1 Reference model terms and definitions
  3.2 Service convention terms and definitions
  3.3 Common data-link service terms and definitions
  3.4 Additional Type 8 data-link specific definitions
  3.5 Common symbols and abbreviations
  3.6 Common conventions
4 Data-link service and concepts
  4.1 Overview
  4.2 Sequence of primitives
  4.3 Connection-mode data-link services
5 DL-management service
  5.1 Scope
  5.2 Facilities of the DL-management service
  5.3 Overview of services
  5.4 Overview of interactions
  5.5 Detailed specification of services and interactions
Bibliography
Annex ZA (normative) - Normative references to international
                       publications with their corresponding
                       European publications

It provides common elements for basic time-critical messaging communications between devices in an automation environment. The term 'time-critical' is used to represent the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time window risks failure of the applications requesting the actions, with attendant risk to equipment, plant and possibly human life. It includes the following significant changes with respect to the previous edition 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.