EtherCAT入门教程.docx

EtherCAT入门教程.docx

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EtherCAT入门教程

EtherCAT入门教程

本文翻译了kithara官方文档，也加入了一些理解，暂时

做得还不够完美，后续补充修正。

2014.06.06

EtherCAT

ThistutorialdescribesthefollowingtopicsusingtheEtherCAT

API

本向导描述了使用EtherCATAPI的功能说明Creatinga

EtherCATmasterassignedtoanetworkadapterCreatingslavesassignedtothemasterReal-timeprocessdataexchangewithdatasetsandassignedPDOsReal-timeup/downloadofservicedataobjects（SDO）Real-timemailboxcommunicationStatecontrolformasterandslavesGettinginformationformaster,

slaves,dataobjects,variableobjects中文说明创建EtherCAT主

实时过程数据交互Masterrelatedfunctions主站相关功能

Openinganetworkadapter打开网卡

Beforewecancreateamaster,itisnecessarytoopenanetworkadapterfirst.Thisisdonebyusingthefunction

KS_openAdapter.Asparametersanadaptername,areceiveandasendpoolsizeisneeded.Theadapternameisusuallythenameofanetworkdevice.ThefunctionKS_enumDevicesenumerates

alldevices.Toonlygetnetworkdevicestheparameter

打开网卡，需要的参数包括网卡名称，收发数据池大小等。

可以使用KS_enumDevices枚举设备获取网卡名称，使用该函数时参数deviceType应该设置为“NET”

MindthatthefunctionKS_openAdaptermustbecalledwiththeflagKSF_REALTIME_EXEC.

使用KS_openAdapter时需要将标志位flag设置为

ksError

KSF_REALTIME_EXEC，表明网卡运行在实时模式。

=KS_enumDevices（//枚举设备

"NET",

//Searchesfornetworkdevices

zero

name

if（ksError）

handlepointer

theController

Length

if（ksError）//...ForfurtherdetailsseeHowtolookupfordevices.

Creatingamaster创建主站

TocreateamasterthefunctionKS_createEcatMastercanbeused.AsparametersanetworkadapterhandleandapathtodevicedescriptionXMLfilesareneeded.Anameofatopologyfile（*.ktp）isoptional.ThedevicedescriptionXMLfilescanbefoundwithadeveloperinstallationintheXMLdirectoryorcanbedownloadedfromtheslavemanufacturerwebsite.AtopologyfilecanbecreatedwiththeKithara?

MasterMonitor?

.

使用KS_createEcatMaster创建主站，需要传入网卡句柄参数和从站XML设备描述文件路径，也可以加入一个拓扑文件

ktp参数。

设备描述文件可以从设备制造商的网站上获取。

拓扑文件可以用MasterMonitor生成。

TheKithara?

MasterMonitor?

isatoolfore.g.configuration,diagnosticsandsavingXMLconfigurationfilesforgraphicallyviewingslaves,objectsandvariablesorcomparingagiventopologywithatargettopology.

MasterMonitor是一个用于配置、调试和保存xml配置文件的图形化工具，可以查看从站、对象、变量和对比拓扑文件。

Closingamaster关闭主站

Tocloseamasterandfreeallitsresourcesthefunction

KS_closeEcatMastermustbeused.

使用KS_closeEcatMaster关闭从站

Statechangeforamaster主站的状态切换

Toqueryandchangethemaster'sstatethefunctions

KS_queryEcatMasterStateandKS_changeEcatStatecanbeused.

用KS_queryEcatMasterState查询主站状态。

用KS_changeEcatState改变主站状态。

ThefunctionKS_queryEcatMasterStateneedsamasterhandle,apointertothestructureKSEcatMasterStateandflags.BesuretoinitializethestructurememberstructSizetotheactualsizeofthestructureKSEcatMasterStatebeforecallingthefunction.

ThefunctionKS_changeEcatStateneedsamasterhandle,therequestedstateandflagsasparameters.Thestateofallassignedslaveswhichareonlineischanged.SlavesareassignedusingthefunctionKS_createEcatSlaveorKS_createEcatSlaveIndirect.

NearlyeveryEtherCATAPIfunctionhasspecialrequirementsregardingthestate（seetheAPIdocumentationofthespecificfunction）.Forfurtherinformationaboutthestatemachinesee

TheEtherCATstatemachine.

几乎每一个EtherCAT的API函数都需要主站在特定的状态才能使用。

Slaverelatedfunctions从站相关函数

Enumeratingallonlineslaves枚举所有在线从站

Afteramasterwascreated,allonlineslavescanbeenumeratedusingthefunctionKS_enumEcatSlaves.Asparametersamasterhandle,aenumerationindexandapointertothestructure

KSEcatSlaveStateareneeded.BesuretoinitializethestructurememberstructSizetotheactualsizeofthe

structureKSEcatSlaveStatebeforecallingthefunction.

站.需要的参数包括主站句柄、枚举顺序、

KSEcatSlaveState结构体的指针。

在使用前应当初始化结构体的成员变量structSize大小。

Iftheenumerationindexisgreaterthanthenumberofonlineslaves,theerrorcodeKSERROR_DEVICE_NOT_FOUNDisreturned.Otherwise,apointertothestructureKSEcatSlaveStateisreturnedwhichcontainsinformationabouttheslave'sstate.

UsingthefunctionKS_enumEcatSlavestheslavesareenumeratedbytheirabsoluteposition.

Creatingaslave创建从站

Tocreateaslave,oneofthefunctions

KS_createEcatSlaveIndirectorKS_createEcatSlavecanbeused.

ThefunctionKS_createEcatSlaveIndirectmakesuseofthestructureKSEcatSlaveStatewhichcanbeobtainedusingthefunctionKS_enumEcatSlaves.

ThefunctionKS_createEcatSlaveneedsadditionalparameterslikeslaveid,position,vendoridandrevisionnumber.Withtheparameterslaveidarelativepositioncanbeprovided,too.

Theparametersareuniquetoaslavetype.Thisinformationcanbefoundintheslave'smanual,usingthemethodabovewiththestructureKSEcatSlaveStateorcanbedisplayedwiththe

Kithara?

MasterMonitor?

.

Ifaslaveisalreadyassignedandthefunction

KS_createEcatSlaveiscalledwiththesamevendorID,product

ID,revisionnumberandposition,anerror

KSERROR_DEVICE_ALREADY_USEDisreturnedtogetherwithaslavehandletothealreadyassignedslave.

AslavecanbedeletedusingthefunctionKS_deleteEcatSlave.

Gettinginformationfromslaves获取从站信息

Toqueryinformationfromaslavethefunction

KS_queryEcatSlaveInfocanbeused.ItdeliversapointertothestructureKSEcatSlaveInfo.Ifinformationaboutprocessdataobjects（PDO）,servicedataobjects（SDO）orbothareneeded,theflagsKSF_SDOandKSF_PDOcanbepassedtothefunction.Thefunctionistimeconsuming（upto30seconds）andthestatePREOPorhigherisneededforonlineslaves.

WithinthestructureKSEcatSlaveInfothereisanarrayof

KSEcatDataObjInfoandwithinthisstructurethereisanarrayof

KSEcatDataVarInfo.

IfusinglanguageslikeC#thesestructuredcannotbeaccessed.

Alternatively,thefunctionsKS_queryEcatDataObjInfo,

KS_queryEcatDataVarInfo,KS_enumEcatDataObjInfoandKS_enumEcatDataVarInfocanbeusedinstead.

Statechangesforslaves从站状态机改变，与主站类似

Toqueryandchangetheslave'sstatethefunctions

KS_queryEcatSlaveStateandKS_changeEcatStatecanbeused.

查询和改变从站状态可以用以上两个函数，改变状态的函数与改变主站的相同

ThefunctionKS_queryEcatSlaveStateneedsaslavehandle,apointertothestructureKSEcatSlaveStateandflags.BesuretoinitializethestructurememberstructSizetotheactualsizeofthestructureKSEcatSlaveStatebeforecallingthefunction.

查询从站状态函数，需要一个从站句柄、指向

KSEcatSlaveState结构体的指针和标志位。

使用前请初始化结构体内部的structSize变量。

ForfurtherinformationconcerningthestatemachineseeThe

EtherCATstatemachine.

更多的信息可以查看此章节

Otheroperationsonslaves从站的其他操作

UsingthefunctionKS_writeEcatSlaveIditispossibletowriteauniqueIDtoanyslave.TheIDiswrittentonon-volatilememoryandwillbepersistent.WithinaconnectedrealtopologytheIDsmustbeunique.MindthattheslavemustbeinINITstate.

使用KSwriteEcatSlaveld函数可以给从站写入唯一的ID°ID

必须是唯一的，注意此时从站的状态必须是INIT

DatasetrelatedfunctionsDataset相关函数

Adatasetisacollectionofsyncmanagers,asyncmanagercancontainseveralPDOs（processdataobjects）andaPDOcanbemappedtomultipleSDO（servicedataobject）variables.Asyncmanagerisaslaveinternalmechanismtokeepdataconsistent.

个PDO可以映射多个SDO。

Itisnecessarytocreateatleastonedatasettoestablishtheprocessdataexchange.Dataiscyclicallytransferredbetweenthemasterandtheslaves.

建立过程数据通信至少需要一个dataset数据是在主站和从

站之间循环传送的。

Creatingandassigningadataset创建和分配一个dataset

TopreparetheprocessdataexchangeadatasetcanbecreatedwiththefunctionKS_createEcatDataSet.Asparametersamasterhandleisneeded.Optionalparametersareanapplicationandasystempointertoaccesssharedmemoryofthedatasetdirectly.Iftheprogramwascalledfromring3thentheapplicationpointercanbeusedandonring0thesystempointer.

Beforetheprocessdataexchangestarts,aPDOshouldbeassignedusingthefunctionKS_assignEcatDataSet.Asparametersadatasethandle,aslavehandle,anindexofasyncmanagerandaplacementisneeded.

在数据交互之前，应该分配PDO给sync管理器，使用

KS_assignEcatDataSet。

需要输入dataset句柄，从站句柄，sync

管理器序号

Aslavecanhaveseveralsyncmanagers.Thereare

readable/writeablesyncmanagersandsyncmanagersforthemailbox（ifexisting）.Asyncmanagercontainsoneoremore

PDOs.Itispossibletoselectaspecificsyncmanagerwiththeindexparameterorselectgroupsofsyncmanagers（e.g.with

KS_ECAT_SYNC_ALL,KS_ECAT_SYNC_INPUT）.

个从站可以有多个sync管理器。

有可读写sync和邮箱式

sync。

个sync拥有一个或多个PDO。

通过index参数，可以选择一个或一组特定的sync管理器

Severalobjectscanbeassignedtoadatasetwhileno

KSERROR_NOT_ENOUGH_MEMORYisreturned.Perdefaultadatasethasasizeof4KBandcanhaveupto64KB.

MindthattheassignedslavemustbeinstatePREOP.Withtheparameterplacementanoffsetcanbespecifiedwhileassigningseveralobjects.

个dataset可以被分配多个对象，默认的dataset大小为4kb,

最大为64kb。

操作时的从站必须位于PREOP状态。

Placement

参数可以指定一个对象在pdo中的位置。

Itisfurtherpossibletocreatemorethanonedataset.WithmultipledatasetseachonecanbeupdatedwithdifferentfrequenciesorgroupPDOswithmultipledatasetstologicalunits.

也可以创建多个dataset多个dataset中，每一个dataset可以被更新不同频率和不同组PDO更新。

Deletingadataset删除dataset

Todeleteadatasetandfreeallitsresourcesthefunction

KS_deleteEcatDataSetmustbeused.

Postingandreadingprocessdata发送和读取pdo数据

TopostandreadprocessdatathefunctionsKS_postEcatDataSetandKS_readEcatDataSetcanbeused.

Theprocessdataexchangediscontrolledbytheuser.Sothesefunctionsshouldbeplacedinsideofatimercallbackoradatasethandlertoensureanupdateoftheprocessdataexchangeinreal-time.Bothfunctionsneedadatasethandleasparameter.

ThefunctionKS_postEcatDataSethastobecalledbeforethefunctionKS_readEcatDataSe