1.1 General<\/b><\/p>\n
This part of IEC 61158 provides common elements for basic time-critical messaging communications between devices in an automation environment. The term \u201ctime-critical\u201d 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.<\/p>\n
This International Standard defines in an abstract way the externally visible services provided by the Type 4 fieldbus data-link layer in terms of<\/p>\n
the primitive actions and events of the services;<\/p>\n<\/li>\n
the parameters associated with each primitive action and event, and the form which they take; and<\/p>\n<\/li>\n
the interrelationship between these actions and events, and their valid sequences.<\/p>\n<\/li>\n<\/ol>\n
The purpose of this document is to define the services provided to<\/p>\n
the Type 4 fieldbus application layer at the boundary between the application and data-link layers of the fieldbus reference model;<\/p>\n<\/li>\n
systems management at the boundary between the data-link layer and systems management of the fieldbus reference model.<\/p>\n<\/li>\n<\/ul>\n
1.2 Specifications<\/b><\/p>\n
The principal objective of this document is to specify the characteristics of conceptual data- link layer services suitable for time-critical communications, and thus supplement the OSI Basic Reference Model in guiding the development of data-link protocols for time-critical communications. A secondary objective is to provide migration paths from previously-existing industrial communications protocols.<\/p>\n
This specification may be used as the basis for formal DL-Programming-Interfaces. Nevertheless, it is not a formal programming interface, and any such interface will need to address implementation issues not covered by this specification, including<\/p>\n
the sizes and octet ordering of various multi-octet service parameters;<\/p>\n<\/li>\n
the correlation of paired request and confirm, or indication and response, primitives.<\/p>\n<\/li>\n<\/ol>\n
1.3 Conformance<\/b><\/p>\n
This document does not specify individual implementations or products, nor does it constrain the implementations of data-link entities within industrial automation systems.<\/p>\n
There is no conformance of equipment to this data-link layer service definition standard. Instead, conformance is achieved through implementation of the corresponding data-link protocol that fulfills the Type 1 data-link layer services defined in this document.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | National foreword <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | Annex ZA(normative)Normative references to international publicationswith their corresponding European publications <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 9<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | 1 Scope 1.1 General 1.2 Specifications 1.3 Conformance <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 2 Normative references 3 Terms, definitions, symbols, abbreviations and conventions 3.1 Reference model terms and definitions <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 3.2 Service convention terms and definitions <\/td>\n<\/tr>\n | ||||||
| 15<\/td>\n | 3.3 Data-link service terms and definitions <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 3.4 Symbols and abbreviations <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 3.5 Conventions <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 4 Data-link service and concepts 4.1 Overview 4.1.1 General 4.1.2 Overview of DLnaming (addressing) Figures Figure 1 \u2013 Relationship of PhE, DLE and DLS-users <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 4.2 Types and classes of data-link service 4.3 Functional classes 4.4 Facilities of the connectionless-mode data-link service 4.5 Model of the connectionless-mode data-link service 4.5.1 General 4.5.2 Unconfirmed request <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 4.5.3 Confirmed request 4.6 Sequence of primitives 4.6.1 Constraints on sequence of primitives <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 4.6.2 Relation of primitives at the end-points of connectionless service Figure 2 \u2013 Confirmed and unconfirmed Unitdata request time-sequence diagram Figure 3 \u2013 Repeated confirmed request time-sequence diagram Tables Table 1 \u2013 Summary of DLconnectionless-mode primitives and parameters <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 4.6.3 Sequence of primitives at one DLSAP 4.7 Connectionless-mode data transfer functions 4.7.1 General 4.7.2 Types of primitives and parameters Figure 4 \u2013 State transition diagram for sequences of primitives at one DLSAP Table 2 \u2013 Unitdata transfer primitives and parameters <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 5 DLmanagement service 5.1 Scope and inheritance 5.2 Facilities of the DLmanagement service Table 3 \u2013 Control-status error codes <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 5.3 Model of the DLmanagement service 5.4 Constraints on sequence of primitives 5.5 Set 5.5.1 Function Figure 5 \u2013 Sequence of primitives for the DLM action service Table 4 \u2013 Summary of DLmanagement primitives and parameters <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 5.5.2 Types of parameters 5.6 Get 5.6.1 Function 5.6.2 Types of parameters Table 5 \u2013 DLMSet primitive and parameters Table 6 \u2013 DLMGet primitive and parameters <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 5.7 Action 5.7.1 Function 5.7.2 Types of parameters Table 7 \u2013 DLMAction primitive and parameters <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 5.7.3 Sequence of primitives 5.8 Event 5.8.1 Function 5.8.2 Types of parameters Table 8 \u2013 DLMEvent primitive and parameters <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Industrial communication networks. Fieldbus specifications – Data-link layer service definition. Type 4 elements<\/b><\/p>\n |