基本信息
| 标准名称： | 液体比重天平检定规程 |
| 英文名称： | Verification Regulation of Hydrometric Balance |
| 中标分类： | 综合 >> 计量 >> 力学计量 |
| 替代情况： | JJG 171-76;被JJG 171-2004代替 |
| 发布日期： | 1999-11-12 |
| 实施日期： | 2000-10-01 |
| 首发日期： | |
| 作废日期： | 2004-12-01 |
| 出版日期： | |
| 页数： | 12页 |
适用范围
没有内容
前言
没有内容
目录
没有内容
引用标准
没有内容
所属分类： 综合 计量 力学计量
【英文标准名称】:Industrialcommunicationnetworks-Fieldbusspecifications-Part5-20:Applicationlayerservicedefinition-Type20elements【原文标准名称】:工业通讯网络.现场总线规范.第5-20部分:应用层设备定义.20型元件
【标准号】:IEC61158-5-20-2010
【标准状态】:现行
【国别】:国际
【发布日期】:2010-08
【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(数据处理);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;工业设施;信息交换;信息处理;信息技术;接口;接口(数据处理);链路层;开放系统互连;OSI;物理层;过程控制;过程控制工程;过程控制系统;协议规范;协议;信号;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;Digitaldata;Digitalengineering;Digitalsignals;EDP;Electricalengineering;Electronicinstruments;Electronicsystems;Fieldbus;Guidancesystems;Industrialfacilities;Informationinterchange;Informationprocessing;Informationtechnology;Interfaces;Interfaces(dataprocessing);Linklayers;Opensystemsinterconnection;OSI;Physicallayers;Processcontrol;Processcontrolengineering;Processcontrolsystems;Protocolspecification;Protocols;Signals;Transmissionmedia;Transmissionprotocol
【摘要】:ThefieldbusApplicationLayer(FAL)providesuserprogramswithameanstoaccessthefieldbuscommunicationenvironment.Inthisrespect,theFALcanbeviewedasa“windowbetweencorrespondingapplicationprograms.”ThispartofIEC61158providescommonelementsforbasictime-criticalandnon-time-criticalmessagingcommunicationsbetweenapplicationprogramsinanautomationenvironmentandmaterialspecifictoType20fieldbus.Theterm“time-critical”isusedtorepresentthepresenceofatime-window,withinwhichoneormorespecifiedactionsarerequiredtobecompletedwithsomedefinedlevelofcertainty.Failuretocompletespecifiedactionswithinthetimewindowrisksfailureoftheapplicationsrequestingtheactions,withattendantrisktoequipment,plantandpossiblyhumanlife.ThisstandarddefinesinanabstractwaytheexternallyvisibleserviceprovidedbythedifferentTypesofthefieldbusApplicationLayerintermsofa)anabstractmodelfordefiningapplicationresources(objects)capableofbeingmanipulatedbyusersviatheuseoftheFALservice,b)theprimitiveactionsandeventsoftheservice;c)theparametersassociatedwitheachprimitiveactionandevent,andtheformwhichtheytake;andd)theinterrelationshipbetweentheseactionsandevents,andtheirvalidsequences.Thepurposeofthisstandardistodefinetheservicesprovidedtoa)theFALuserattheboundarybetweentheuserandtheApplicationLayeroftheFieldbusReferenceModel,andb)SystemsManagementattheboundarybetweentheApplicationLayerandSystemsManagementoftheFieldbusReferenceModel.ThisstandardspecifiesthestructureandservicesoftheIECfieldbusApplicationLayer,inconformancewiththeOSIBasicReferenceModel(ISO/IEC7498)andtheOSIApplicationLayerStructure(ISO/IEC9545).FALservicesandprotocolsareprovidedbyFALapplication-entities(AE)containedwithintheapplicationprocesses.TheFALAEiscomposedofasetofobject-orientedApplicationServiceElements(ASEs)andaLayerManagementEntity(LME)thatmanagestheAE.TheASEsprovidecommunicationservicesthatoperateonasetofrelatedapplicationprocessobject(APO)classes.OneoftheFALASEsisamanagementASEthatprovidesacommonsetofservicesforthemanagementoftheinstancesofFALclasses.Althoughtheseservicesspecify,fromtheperspectiveofapplications,howrequestandresponsesareissuedanddelivered,theydonotincludeaspecificationofwhattherequestingandrespondingapplicationsaretodowiththem.Thatis,thebehavioralaspectsoftheapplicationsarenotspecified;onlyadefinitionofwhatrequestsandresponsestheycansend/receiveisspecified.ThispermitsgreaterflexibilitytotheFALusersinstandardizingsuchobjectbehavior.Inadditiontotheseservices,somesupportingservicesarealsodefinedinthisstandardtoprovideaccesstotheFALtocontrolcertainaspectsofitsoperation.
【中国标准分类号】:M11
【国际标准分类号】:25_04_40;35_100_70;35_110
【页数】:52P.;A4
【正文语种】:英语
