Tiêu chuẩn quốc tế
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Số hiệu
Standard Number
IEC 61158-3-24:2023
Năm ban hành 2023
Publication date
Tình trạng
A - Còn hiệu lực
Status |
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Tên tiếng Anh
Title in English Industrial communication networks – Fieldbus specifications – Part 3-24: Data-link layer service definition – Type 24 elements
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Thay thế cho
Replace |
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Chỉ số phân loại Quốc tế (ICS)
By field |
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Số trang
Page 44
Giá:
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Phạm vi áp dụng
Scope of standard General This part of IEC 61158 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. This document defines in an abstract way the externally visible service provided by the Type 24 fieldbus data-link layer in terms of • the primitive actions and events of the service; • the interrelationship between these actions and events, and their valid sequences; • the parameters associated with each primitive action and event, and the form which they take. The purpose of this document is to define the services provided to • the Type 24 fieldbus application layer at the boundary between the application and data-link layers of the fieldbus reference model; • systems management at the boundary between the data-link layer and systems management of the fieldbus reference model. Specifications 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. This document can be used as the basis for formal DL-Programming-Inter • the sizes and octet ordering of various multi-octet service parameters, and • the correlation of paired request and confirm, or indication and response, primitives. Conformance This document does not specify individual implementations or products, nor does it 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 fulfills the Type 24 data-link layer services defined in this document. |