標準號：IEC 61158-4-8-2007
中文標準名稱：工業通訊網絡.數據總線規范.第4-8部分:數據聯絡層協議規范.8型元件
英文標準名稱：Industrial communication networks - Fieldbus specifications - Part 4-8: Data-link layer protocol specification - Type 8 elements
標準類型：N18;P76
發布日期：1999/12/31 12:00:00
實施日期：1999/12/31 12:00:00
中國標準分類號：N18;P76
國際標準分類號：25.040.40;35.100.20;35.160;35.240.50
引用標準：IEC 61158-2;IEC 61158-3-8;ISO/IEC 7498-1;ISO/IEC 7498-3;ISO/IEC 10731
適用范圍：1.1 GeneralThe data-link layer provides basic time-critical messaging communications between devices inan automation environment.This protocol provides a highly-optimized means of interchanging fixed-length input/outputdata and variable-length segmented messages between a single master device and a set ofslave devices interconnected in a loop (ring) topology. The exchange of input/output data istotally synchronous by configuration, and is unaffected by the messaging traffic.Devices are addressed implicitly by their position on the loop. The determination of thenumber, identity and characteristics of each device can be configured, or can be detectedautomatically at start-up.1.2 SpecificationsThis standard specifiesa) procedures for the timely transfer of data and control information from one data-link userentity to a peer user entity, and among the data-link entities forming the distributed datalinkservice provider;b) the structure of the fieldbus DLPDUs used for the transfer of data and control informationby the protocol of this standard, and their representation as physical interface data units.1.3 ProceduresThe procedures are defined in terms ofa) the interactions between peer DL-entities (DLEs) through the exchange of fieldbusDLPDUs;b) the interactions between a DL-service (DLS) provider and a DLS-user in the same systemthrough the exchange of DLS primitives;c) the interactions between a DLS-provider and a Ph-service provider in the same systemthrough the exchange of Ph-service primitives.1.4 ApplicabilityThese procedures are applicable to instances of communication between systems whichsupport time-critical communications services within the data-link layer of the OSI or fieldbusreference models, and which require the ability to interconnect in an open systemsinterconnection environment.Profiles provide a simple multi-attribute means of summarizing an implementation’scapabilities, and thus its applicability to various time-critical communications needs.1.5 ConformanceThis standard also specifies conformance requirements for systems implementing theseprocedures. This standard does not contain tests to demonstrate compliance with suchrequirements.