BS EN 61158-3-21:2012
$189.07
Industrial communication networks. Fieldbus specifications – Data-link layer service definition. Type 21 elements
| Published By | Publication Date | Number of Pages |
| BSI | 2012 | 48 |
1.1 Overview
This part of IEC 61158 provides the common elements for basic time-critical messaging communications between devices in an automation environment. The term “time-critical” in this context means the prioritized full-duplex collision-free time-deterministic communication, of which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the required time risks the failure of the applications requesting the actions, with attendant risk to equipment, plant, and possibly human life.
This standard defines in an abstract way the externally visible service provided by the Type 21 data-link layer in terms of:
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the primitive actions and events of the service;
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the parameters associated with each primitive action and event, and the form that they take; and
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the interrelationships between these actions and events, and their valid sequences.
The purpose of this standard is to define the services provided to:
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The Type 21 application layer at the boundary between the application and DLLs of the fieldbus reference model;
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Systems management at the boundary between the DLL and the systems management of the fieldbus reference model.
1.2 Specifications
The principal objective of this standard is to specify the characteristics of conceptual DLL services suitable for time-critical communications, and to 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.
This standard may be used as the basis for formal data link programming interfaces. Nevertheless, it is not a formal programming interface, and any such interface will need to address implementation issues not covered by this standard, including:
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The sizes and octet ordering of various multi-octet service parameters;
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The correlation of paired primitives for request and confirm, or indication and response.
1.3 Conformance
This standard does not specify individual implementations or products, nor do they constrain the implementations of data-link entities within industrial automation systems.
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 fulfils the Type 21 DLL services defined in this standard.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 6 | CONTENTS |
| 8 | INTRODUCTION |
| 9 | 1 Scope 1.1 Overview 1.2 Specifications 1.3 Conformance |
| 10 | 2 Normative references 3 Terms, definitions, symbols, abbreviations, and conventions 3.1 Reference model terms and definitions |
| 12 | 3.2 Service convention terms and definitions 3.3 Data link service terms and definitions |
| 15 | 3.4 Symbols and abbreviations |
| 16 | 3.5 Conventions |
| 17 | 4 Data-link layer services and concepts 4.1 General |
| 18 | Figures Figure 1 – Full-duplex flow control Figure 2 – Sequence diagram of DL DATA service |
| 19 | Figure 3 – Sequence diagram of DL SPDATA service Figure 4 – Sequence diagram of NCM service primitive |
| 20 | Figure 5 – Relationships of DLSAPs, DLSAP-addresses, and group DL addresses Tables Table 1 – Destination DL address |
| 21 | 4.2 Detailed description of the data service Figure 6 – DL DATA service |
| 22 | Table 2 – Primitives and parameters used in DL DATA service Table 3 – DL DATA Primitives and Parameters |
| 23 | 4.3 Detailed description of the sporadic data service |
| 24 | Table 4 – Primitives and parameters used in DL SPDATA service Table 5 – DL SPDATA Primitives and Parameters |
| 25 | 4.4 Detailed description of network control message service Table 6 – Primitives and parameters used on DL NCM_SND service |
| 26 | Table 7 – DL NCM_SND Primitives and Parameters |
| 27 | Table 8 – Summary of Network Control Message Type |
| 28 | 5 Data-link management services 5.1 General 5.2 Data link management service (DLMS) facilities 5.3 Data link management service (DLMS) |
| 29 | 5.4 Overview of interactions |
| 30 | Figure 7 – Sequence diagram of Reset, Set-value, Get-value, SAP-allocation, SAP-deallocation, Get-SAP information and Get-diagnostic information service primitives Table 9 – Summary of DL management primitives and parameters |
| 31 | 5.5 Detailed specification of service and interactions Figure 8 – Sequence diagram of Event service primitive Table 10 – DLM-RESET primitives and parameters |
| 32 | Table 11 – DLM-SET_VALUE primitives and parameters |
| 33 | Table 12 – DLM-GET_VALUE primitives and parameters |
| 34 | Table 13 – DLM-SAP_ALLOC primitives and parameters |
| 35 | Table 14 – DLM-SAP_DEALLOC primitives and parameters Table 15 – DLM-GET_SAP_INFO primitives and parameters |
| 36 | Table 16 – DLM-GET_DIAG primitives and parameters |
| 37 | Table 17 – DLM-EVENT primitives and parameters |
| 38 | Table 18 – DLM event identifier Table 19 – DLM-GET_PATH primitives and parameters |
| 39 | 6 MAC control service 6.1 General 6.2 MAC control service 6.3 Overview of interactions |
| 40 | 6.4 Detailed specification of service and interactions Figure 9 – Sequence diagram of MAC-reset and MAC-forward-control service primitive Table 20 – Summary of MAC control primitives and parameters Table 21 – MAC-RESET primitives and parameters |
| 41 | Table 22 – MAC-FW_CTRL primitives and parameters |
| 42 | 7 Ph control service 7.1 General 7.2 Ph control service 7.3 Overview of interactions Table 23 – Summary of Ph control primitives and parameters |
| 43 | 7.4 Detailed specification of service and interactions Figure 10 – Sequence diagram of Ph reset and Ph get-link-status service primitive Figure 11 – Sequence diagram of Ph link-status-change service primitive Table 24 – Ph RESET primitives and parameters |
| 44 | Table 25 – Ph GET_LINK_STATUS primitives and parameters |
| 45 | Table 26 – Ph LINK_STATUS _CHANGE primitives and parameters |
| 46 | Bibliography |
