【英文标准名称】:Industrialcommunicationnetworks-Fieldbusspecifications-Part3-2:Data-linklayerservicedefinition-Type2elements
【原文标准名称】:工业通讯网络.数据总线规范.第3-2部分:数据联络层设备定义.2型元件
【标准号】:IEC61158-3-2-2007
【标准状态】:现行
【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;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(数据处理);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;信号;规范;规范(验收);传输媒质
【英文主题词】:Bussystems;Buses(dataprocessing);Circuitnetworks;Communication;Controlequipment;Controlsystems;Controltechnology;Datacommunication;Datalinklayers;Datalinksystem;Dataprocessing;Dataservices;Datatransfer;Definitions;Digital;Digitaldata;Digitalengineering;EDP;Electronicinstruments;Electronicsystems;Englishlanguage;Fieldbus;Guidancesystems;Industrial;Industrialfacilities;Informationinterchange;Informationprocessing;Informationtechnology;Interfaces(dataprocessing);Linklayers;Opensystemsinterconnection;OSI;Processcontrol;Processcontrolengineering;Processcontrolsystems;Signals;Specification;Specification(approval);Transmissionmedia
【摘要】:1.1OverviewThispartofIEC61158providescommonelementsforbasictime-criticalmessagingcommunicationsbetweendevicesinanautomationenvironment.Theterm“time-critical”isusedtorepresentthepresenceofatime-window,withinwhichoneormorespecifiedactionsarerequiredtobecompletedwithsomedefinedlevelofcertainty.Failuretocompletespecifiedactionswithinthetimewindowrisksfailureoftheapplicationsrequestingtheactions,withattendantrisktoequipment,plantandpossiblyhumanlife.ThisstandarddefinesinanabstractwaytheexternallyvisibleserviceprovidedbytheType2fieldbusdata-linklayerintermsofa)theprimitiveactionsandeventsoftheservice;b)theparametersassociatedwitheachprimitiveactionandevent,andtheformwhichtheytake;andc)theinterrelationshipbetweentheseactionsandevents,andtheirvalidsequences.Thepurposeofthisstandardistodefinetheservicesprovidedto:?theType2fieldbusapplicationlayerattheboundarybetweentheapplicationanddata-linklayersofthefieldbusreferencemodel;?systemsmanagementattheboundarybetweenthedata-linklayerandsystemsmanagementofthefieldbusreferencemodel.Type2DL-serviceprovidesbothaconnectedandaconnectionlesssubsetofthoseservicesspecifiedinISO/IEC8886.1.2SpecificationsTheprincipalobjectiveofthisstandardistospecifythecharacteristicsofconceptualdata-linklayerservicessuitablefortime-criticalcommunicationsandthussupplementtheOSIBasicReferenceModelinguidingthedevelopmentofdata-linkprotocolsfortime-criticalcommunications.Asecondaryobjectiveistoprovidemigrationpathsfrompreviously-existingindustrialcommunicationsprotocols.ThisspecificationmaybeusedasthebasisforformalDL-Programming-Interfaces.Nevertheless,itisnotaformalprogramminginterface,andanysuchinterfacewillneedtoaddressimplementationissuesnotcoveredbythisspecification,including:a)thesizesandoctetorderingofvariousmulti-octetserviceparameters;b)thecorrelationofpairedrequestandconfirm,orindicationandresponse,primitives.1.3ConformanceThisstandarddoesnotspecifyindividualimplementationsorproducts,nordoesitconstraintheimplementationsofdata-linkentitieswithinindustrialautomationsystems.hereisnoconformanceofequipmenttothisdata-linklayerservicedefinitionstandard.Instead,conformanceisachievedthroughimplementationofthecorrespondingdata-linkprotocolthatfulfillstheType1data-linklayerservicesdefinedinthisstandard.
【中国标准分类号】:N18;P76
【国际标准分类号】:25_040_40;35_100_20;35_160
【页数】:50P;A4
【正文语种】:英语


【英文标准名称】:Latex,rubber,naturalconcentrate-Determinationofdryrubbercontent
【原文标准名称】:浓缩天然橡胶胶乳干胶含量的测定
【标准号】:ISO126-1995
【标准状态】:作废
【国别】:国际
【发布日期】:1995-12
【实施或试行日期】:
【发布单位】:国际标准化组织(ISO)
【起草单位】:ISO/TC45
【标准类型】:()
【标准水平】:()
【中文主题词】:胶乳;干物质;天然橡胶;测定;含量测定;橡胶;硫化橡胶;定义
【英文主题词】:vulcanizedrubber;definitions;definition;naturalrubber;determinationofcontent;latices;determination;rubber;drymatter
【摘要】:
【中国标准分类号】:B72
【国际标准分类号】:83_040_10
【页数】:3P;A4
【正文语种】:英语