標準號：BS EN 61158-4-17-2008
中文標準名稱：工業通訊網絡.現場總線規范.數據鏈路層協議規范.17型元件
英文標準名稱：Industrial communication networks — Fieldbus specifications — Part 4-17: Data-link layer protocol specification — Type 17 elements
標準類型：N17
發布日期：2008/5/30 12:00:00
實施日期：2008/5/30 12:00:00
中國標準分類號：N17
國際標準分類號：35.100.20;35.160;35.240.50
引用標準：IEC 61158-3-17;ISO/IEC 7498;ISO/IEC 8802-3;ISO/IEC 10731;IEEE Std 802.3ab;RFC 768;RFC 791;RFC 792;RFC 826;RFC 894;RFC 1112;RFC 2236
適用范圍：1.1 GeneralThe data-link layer provides basic time-critical messaging communications between devices inan automation environment.This protocol provides communication opportunities to all participating data-link entitiesa) in a cyclic asynchronous manner, sequentially to each of those data-link entities, andb) in a synchronous manner, either cyclically or acyclically, according to a pre-establishedschedule.The specified protocol also provides means of changing the set of participating data-linkentities and of modifying the set of scheduled communications opportunities. When the set ofscheduled communications opportunities is null, the distribution of communicationopportunities to the participating data-link entities is completely asynchronous.Thus this protocol can be characterized as one which provides access asynchronously butwith a synchronous overlay.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.