【英文标准名称】:POWDEREDMILK.DETERMINATIONOFTHEAPPARENTDENSITYBEFOREANDAFTERSHAKINGDOWN.
【原文标准名称】:奶粉.沉降前后表观密度的测定
【标准号】:NFV04-344-1971
【标准状态】:作废
【国别】:法国
【发布日期】:1971-05
【实施或试行日期】:1971-04-27
【发布单位】:法国标准化协会(AFNOR)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:乳制品;测量;体密度;奶粉;试验
【英文主题词】:driedmilk;dairyproducts;bulkdensity;measurement;tests;testing
【摘要】:
【中国标准分类号】:X16
【国际标准分类号】:
【页数】:4P;A4
【正文语种】:其他


【英文标准名称】:Industrialcommunicationnetworks-Fieldbusspecifications-Part4-2:Data-linklayerprotocolspecification-Type2elements
【原文标准名称】:工业通讯网络.数据总线规范.第4-2部分:数据联络层协议规范.2型元件
【标准号】:IEC61158-4-2-2007
【标准状态】:作废
【国别】:国际
【发布日期】:2007-12
【实施或试行日期】:
【发布单位】:国际电工委员会(IX-IEC)
【起草单位】:IEC/SC65C
【标准类型】:()
【标准水平】:()
【中文主题词】:总线系统;总线;电路网络;通信;控制设备;控制系统;控制工艺学;数据通信;数据链层;数据连接系统;数据处理;数据设备;数据传送;定义;数字的;数字数据;数字工程;数字信号;电子数据处理;电气工程;电子仪器;电子系统;现场总线;制导系统;工业的;工业设施;信息交换;信息处理;信息技术;接口;链路层;开放系统互连;OSI;过程控制;过程控制工程;过程控制系统;协议规范;协议;信号;规范;规范(验收);传输媒质;传输协议
【英文主题词】:Bussystems;Buses(dataprocessing);Circuitnetworks;Communication;Controlequipment;Controlsystems;Controltechnology;Datacommunication;Datalinklayers;Datalinksystem;Dataprocessing;Dataservices;Datatransfer;Definitions;Digital;Digitaldata;Digitalengineering;Digitalsignals;EDP;Electronicinstruments;Electronicsystems;Englishlanguage;Fieldbus;Guidancesystems;Industrial;Industrialfacilities;Informationinterchange;Informationprocessing;Informationtechnology;Interfaces;Interfaces(dataprocessing);Linklayers;Opensystemsinterconnection;OSI;Processcontrol;Processcontrolengineering;Processcontrolsystems;Protocolspecification;Protocols;Signals;Specification;Specification(approval);Transmissionmedia;Transmissionprotocol
【摘要】:1.1GeneralThedata-linklayerprovidesbasictime-criticalmessagingcommunicationsbetweendevicesinanautomationenvironment.Thisprotocolprovidescommunicationopportunitiestoallparticipatingdata-linkentities,sequentiallyandinacyclicsynchronousmanner.Foregroundscheduledaccessisavailablefortime-criticalactivitiestogetherwithbackgroundunscheduledaccessforlesscriticalactivities.Deterministicandsynchronizedtransferscanbeprovidedatcyclicintervalsupto1msanddeviceseparationsof25km.Thisperformanceisadjustabledynamicallyandon-linebyreconfiguringtheparametersofthelocallinkwhilstnormaloperationcontinues.Bysimilarmeans,DLconnectionsandnewdevicesmaybeaddedorremovedduringnormaloperation.Thisprotocolprovidesmeanstomaintainclocksynchronizationacrossanextendedlinkwithaprecisionbetterthan10μs.ThisprotocoloptimizeseachaccessopportunitybyconcatenatingmultipleDLSDUsandassociatedDLPCIintoasingleDLPDU,therebyimprovingdatatransferefficiencyfordatalinkentitiesthatactivelysourcemultiplestreamsofdata.Themaximumsystemsizeisanunlimitednumberoflinksof99nodes,eachwith255DLSAPaddresses.Eachlinkhasamaximumof224relatedpeerandpublisherDLCEPs.1.2SpecificationsThisstandardspecifiesa)proceduresforthetimelytransferofdataandcontrolinformationfromonedata-linkuserentitytoapeeruserentity,andamongthedata-linkentitiesformingthedistributeddatalinkserviceprovider;b)thestructureofthefieldbusDLPDUsusedforthetransferofdataandcontrolinformationbytheprotocolofthisstandard,andtheirrepresentationasphysicalinterfacedataunits.1.3ProceduresTheproceduresaredefinedintermsofa)theinteractionsbetweenpeerDL-entities(DLEs)throughtheexchangeoffieldbusDLPDUs;b)theinteractionsbetweenaDL-service(DLS)providerandaDLS-userinthesamesystemthroughtheexchangeofDLSprimitives;c)theinteractionsbetweenaDLS-providerandaPh-serviceproviderinthesamesystemthroughtheexchangeofPh-serviceprimitives.1.4ApplicabilityTheseproceduresareapplicabletoinstancesofcommunicationbetweensystemswhichsupporttime-criticalcommunicationsserviceswithinthedata-linklayeroftheOSIorfieldbusreferencemodels,andwhichrequiretheabilitytointerconnectinanopensystemsinterconnectionenvironment.Profilesprovideasimplemulti-attributemeansofsummarizinganimplementation’scapabilities,andthusitsapplicabilitytovarioustime-criticalcommunicationsneeds.1.5ConformanceThisstandardalsospecifiesconformancerequirementsforsystemsimplementingtheseprocedures.Thisstandarddoesnotcontainteststodemonstratecompliancewithsuchrequirements.
【中国标准分类号】:N18;P76
【国际标准分类号】:25_040_40;35_100_20;35_160;35_240_50
【页数】:224P;A4
【正文语种】:英语