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指导教师：

赵肖宇

所在学院：

信息技术学院

专业：

通信工程

中国·

大庆

2011年5月

[原文]

IndustrialEthernetandIntelligentBuilding

1IndustrialEthernetthebackground

1.1Unifiedfieldbusstandardsdashed,thetemptationremains

In1984theUnitedStatesproceedtodevelopinternationalstandardsfieldbus,afewyears,themajorcompaniesforcommercialinterests,Fieldbusstandardscannotalwaysuniform.Throughmultiplevoting,consultation,inJanuary2000announcedthatthefieldbusinternationalstandardsIEC61158willbeeightbus（Prefabs,Interfuse,P-NET,World,etc.）

network（TCP/IPEthernet）,inordertoachieveintegratedmanagementofitsnetworkstructure。

（2）IntelligentBuildingoftheurbaninformationsystemintegration,thedevelopmentofdigital,intelligentbuilding（includingintelligentresidentialdistrict）,hasbecomeadigitalcity'

sinformationsite,inordertoachieveinformationsharing,theneedtoachievecontrolnetworkandinformationnetworkofverticalintegration,thatis,ControlnetworkandTCP/IPEthernetintegration.

Asvarioussubsystemsandcommunicationsequipmentatthesceneagreementisdiversifiedandintegratedthesetwomodelsmustbedevelopedgateways,inordertoachievetheconversionagreementandunity,thishasincreasedthecomplexityofsystemintegrationtechnologyandincreasecosts.ItwasboldlyputforwardcanuseTCP/IPprotocolasaunifiedagreement,thesceneofthesubsystemsandequipmentdirectlyfromEthernettosimplifythesystemintegrationoftechnicaldifficulty,lowercosts,sothatcontrolsignalsdirectlyfromtheEthernettransmission,SotheconceptofindustrialEthernethasbeenraised.

2EthernetandCSMA/CD

2.1Ethernet

Ethernet（Ethernet）1975bytheUnitedStatesXEROXcompanysuccessfullydeveloped,asapassivemedium（suchastwistedpair,coaxialcable,etc.）todisseminateinformation,tothehistoryofthespreadofelectromagneticwavesknownasthe"

Ethernet"

（Ether）Toname.

1980bytheDEC,INTEL,XEROXjointlylaunchedathreeEthernetV2,istheworld'

sfirstLANstandard.1983IEEEE802CommitteeDIXEthernetV2basedintroducedIEEE803,usingtheCSMA/CDMACtechnology.802.3refertoaCSMA/CDnetworks,andEthernetDIXEthernetV2fromthestandarddefinition,notstrictlyinthecircumstances,canbecalled802.3LAN,whichisEthernet.

Tothemodernmanufacturingindustryasanexample,itsmodernmanufacturingautomationmodelinFigure.IndustrialEthernetisthecommercialapplicationofEthernettoindustrialcontrolsystems,thetwonetworksisnotessentiallydifferentfrom,thetwoarecompatible.

2.2CSMA/CD（CarrierSenseMultipleAccesswithCollisionDetection

Multi-carriermonitoringvisit/conflictdetection）

CSMA/CDarethefirstimprovementcomesfromCSMA.

（1）CSMA（Carriermonitormultipleaccess）:

stoptryingtosendasignal,firstofalltomonitorbus,todeterminewhetherthereisothermedia,tostopthesignal.

•Ifthemediaisfree,youcansend;

•Ifthemediaareinworkingcondition,thenwaitsometryagainaftertheinterval,whenheardinabusystatemedia,CSMAThereareseveraldifferentwaystodealwith,theavailabilityofinterceptionofsignal:

adheretonon-CSMA,1-adheretoCSMA,P--ConsistentlyCSMA.

（2）CSMA/CDtohearnotonlythefirst,butalsoBaitingBainhair,abusintheconflict,butoncetheconflictwasdetected;

theystoppedsendingtheframe,togiveuptheirownframe.Inordertoknowthatotherstationscanalsohaveaconflict,listeningtotheconflicttothebusstationonthespreadofablockingsignalinterference,informedthebusstationintheconflicthavetakenplace,thecapacityofthischannelwillnotbesentbecausetheframewasdamagedandwaste.Withtheincreasednetworkload,thecollisionwouldincreasetheopportunities,networkefficiencydecreasedsignificantly.

3IndustrialEthernettheexistingproblems

FieldBusisusedforindustrialcontrolandcomplexandharshenvironmentofindustrialdesignatthescene,thesystemofreal-timeandresponsetimehavestrictdemandsonelectricityuseoftheenvironment,therearespecialrequirements.SinceEthernetisdesignedforinformationandcommunications,industrialcontrolfortheexistenceofthefollowingquestions:

（1）usingEthernetCSMA/CDAccessProtocol,whichisanon-deterministicnetwork.Thehighdemandforreal-timecontrolsystems,thisuncertaintywillresultintherequestedinformationcannotconvey.Theso-callednetworksegmentisevensharedthesamebusnetwork,youcanlistentothemessagesentbytheotherside,atthesamecollisionregionalconflict（aconflictthatwillimpacttheregion）ofworkstationsandserverstoconnectthenetworkarea.Forexample,inacollisionconflictintheregionhaveaworkinggroup（fromaserverandworkstationcomponentsmultiple）,whenmorethanonevisitaserverworkstation,duetotheCSMA/CDboundbythesametimeallowingonlyaworkstationandserverCommunications,canonlywaitfortheotherworkstations.Competitionfortheworkstationcommunicationchannelsothatthecommunicationworkstationshavedelayed,andthisextension

Whenthetimeisuncertain,workstationsmorecompetitionforcommunicationsforthelongerthissituationknownastheloadwasmoreseverethelongerthewaitingtime.

Ifinacollisiondomain,assumethattwoworkinggroups,inacollisiondomain,thefirstworkgroupservers,workstationsaccesstocompetitivebroadbandnetworks（suchas100M）,anotherworkinggroupofallworkstationsandserversAreinawaitstateandcannotrun.Thetwoworkinggroupstosplittheoriginalbroadbandnetwork（100M）,aworkinggroupwork,mustwaitforanothergroup,thishasnotonlydelayed,andthisdelayisuncertain.AsCSMA/CDhaveunforeseendelay,particularlyintheheavyload,themorereal-timedatatransmissioncannotbeguaranteed.ThereforeEthernetcontrolsystemmustbesolvedforreal-timeanduncertainty.

（2）EthernetinreliabilitythanBusatthescene.FieldBusisdesignedforindustrialcontrol,abletoadaptflammable,explosive（suchaschemicals,pharmaceuticals）,stronginterferenceandotheroccasionspoorenvironmentoccasions.Fieldbushaveshielding,groundingandexplosion-proofmeasures,suchasEthernetandtheneedtoaddresstheseissues.

（3）Fieldbusspecificationsonthenetworksegmentwithapowersupply.Forallnon-self-poweredequipmenttopowerandEthernetdoesnotprovidepower,theneedforadditionalelectricitysupplylines.

4feasibilityoftheapplicationofIndustrialEthernet

IndustrialEthernetforindustrialcontrol,theabove-mentionedproblems,withtheEthernettechnologydevelopmentandtheimplementationofcorrespondingmeasures,infact,andtheuncertaintycanbemadegreatimprovements:

（1）ContinuouslyimproveEthernetrate:

therateinrecentyearsEthernetfrom10Mbps,100Mbpsto1000Mbpsandhasbeenwidelyapplied.Atpresent10GapsEthernethasbeencommercialized,greatlyshorteningthedatatransmissiontime,improveresponsetime,thesystem'

sreal-timeandnonuncertaintieshaveimproved.

（2）usingEthernetswitchtechnology:

astheworksitesharedEthernetchannelcompetitionarisingfromtheconflictaffectedthecollisionofreal-timesystemanduncertainty,Ethernetswitchtechnologycanbeusedtobeimproved.Ethernet-basedexchangeusedinEthernetswitch,switchbetweentheportatthesametimecancreateanumberofdatachannels,eachconnectedtoanetworkport,theportframebetweentheinputandoutputnolongersubjecttoCSMA/CDMACboundbytheagreement.Whenthesystemincludesanumberofworkinggroups,ingeneralsothateachgroupformedaseparatenetworksegment,eachoftheoccupationoftheexchangenetwork（of）aport（showninFigure4switchesareA,B,C,D4net）,netofmostofthetimetheworkisindependent,whenanytwooftheneedforinformationexchangenetwork,theswitchintwoindependentnetworkofinformationbetweenthechannel.Oncetheendoftheexchangeofinformation,accessisdisconnected.

ThisshowsthatswitchedEthernetsharedEthernetcanbeovercomeexistingproblems:

•Switchesoneachportcanconnectanetworksegment;

eachofthenetworkbandwidthcanbeexclusive;

•switchesoneachport,thenetworkofaccessbetweentheindependentandisolated,suchastheneedforinter-networkofinformationandcommunication,itcantemporarilyestablishaninformationchannel,aftertheswitchisolation,cangreatlyreducetheprobabilityofconflictToimprovethereal-timeanduncertainty;

•switchVLANtechnologycommonlyusedtoexchangecontrolsystemcanbeallocatedtotheproprietaryinformation,accessandbandwidth,thusensuringthenetwork'

sbusiesttime,thecontrolsystemisstillcomfortableenoughbandwidthtoenableEthernettransmissionofreal-timeinformationAnduncertaintyremainedlargelytheoreticallevel.

（3）Insomeapplicationstoallowthecircumstances:

trytocontrolnetworkandinformationnetworkstouseseparate,inordertoavoidreal-timedataandnon-real-timedataofthecollision,betweentheindustrialsiteforindependentEthernetnetworksegment,Therebyimprovingthereal-timeanduncertainty.Inaddition,full-duplextechnologycanbeusedtoreducenetworkload,andEthernet+TCP/IPprotocolonthebasisofauniformandapplytotheindustrialfieldofapplication-levelcontrolmeasuressuchastechnicalspecifications.TheabovemeasurescanbetakensothatinsomeindustrialEthernetmilitary,industrial,civilianareasofthesitehasbeeninitiallyappliedinthemeasurementandcontrol.Forexample,manycountriesabroadnuclearacceleratorastheEthernetmonitoringa