CLXtipsTaskWord格式文档下载.docx
- 文档编号:21582028
- 上传时间:2023-01-31
- 格式:DOCX
- 页数:20
- 大小:407.82KB
CLXtipsTaskWord格式文档下载.docx
《CLXtipsTaskWord格式文档下载.docx》由会员分享,可在线阅读,更多相关《CLXtipsTaskWord格式文档下载.docx(20页珍藏版)》请在冰豆网上搜索。
∙RSLinks2.2
FactsonScanTime:
ProgramScanTime:
Scantimeofindividualprogramwithinatask.Thistimerepresentsthetimeittakestoscantheprogram,notincludinginterruptions.
MaximumTaskScanTime:
MaximumScantimeaparticulartaskusedsincethetimeitwasscheduled.
TaskModelinControlLogix
Objective1-UnderstandingScanTimeandoverheadtimeslice
YourActions
StarttheProjectcalledPVCComponding_Lab.
1.
Expandthemaintaskintheorganizerandnoticethenumberofsubroutinesintheprogram.Asasidenote,noticesomeofthennuancesofthisactualapplication:
a.
Afairlylargenumberofuser-definedstructuresbeingusedinthisapplication.
b.ThevariousInputOutputmodules.
Anyway,goingbacktothetaskathand,selectthemaintaskandrightclickwithyourmouse.Godowntothepropertiesandthenclickontheconfigurationtab.
2.
NoticethescanTimesinmicroseconds.TheMaxrepresentsthemaximumtimethecontrollertooktoprocesstheentireprogramtillnow.Thelastindicatesthetimetakenbythelastscantooktoexecutetheprogram
Objective1-UnderstandingScanTimeandoverheadtimeslice
3.NotedownthisvaluesintheTaskModelWorkSheet1atSl.No.1
4.ResettheMaxScanandnoticetheupdatedmaximumscan.NotedownthesevaluesontheTaskModelWorkSheet1atSl.No.2
TaskModelWorkSheet1
SLNo
Activity
RecordedTime
1
MainTaskMaximumTimeinmicroSeconds
2
MainTaskMaximumTimeinmicrosecondsafterresetting.
5.
RightclicktoselectpropertiesunderthecontrollercalledPVC_Compounding.NowclickontheAdvancedtabinthefolder.NoticetheSystemOverheadtimeslice.ChangethesystemOverHeadtimeslicefrom10to90%(afterchangingpressapply)andmonitortheeffectthishasonthemaintaskscantime(afterrecordingtheeffectresetthemaximumtime).RecordyourobservationsintheWorkSheet2below:
WorkSheet2
SLNo.
SystemOverHeadTimeSlice.
MainTaskMaximumTimeMicroSec.
10
20
3
30
4
40
5
50
6
60
7
70
8
80
9
90
6.Getintoadiscussionwithintheclasswiththehelpofyourinstructortovalidateyourfindings.Theauthor’scommentsonthiscanbefoundattheendofthislab.
FACTS:
TheLogix5000allowsyoutoallocateapercentageoftheCPUtimetoperformthebackgroundCPUfunctions(likeprogramterminalsupport,CommunicationswithHMI,Re-establishandmonitorIOconnectionsandstatus,ControlLogixmessagingetc).Bydefault,thistimeissetto10%.Whichmeansthatforevery10millisecondofcontinuoustaskexecution,amillisecondisassignedtotheCPUoverheadfunction.
Analysis
Thedatarecordedinworksheet2canbeplottedasabove.Asweincreasetheoverheadtimesliceparameterthemaintasktimegoesonincreasing.SothereasonablevaluefortheOverHeadtimesliceparameterisintherangeof10%to35%.
Thereareapplicationswherenotonlythecontrollerhastohandlelotofcommunicationtaskbutalsoneedtoexecutesomesectionsoftheplantatadeterministicrate.Forexamplewewanttohaveanoverheadtimesliceof45%sothattheHMIdatagetsreportedatafasterrate.Thiswouldmeanwecan’texecutetheentireprogram(refertheplot)fasterthen4000microseconds.Butifwestillneedasectionoftheprogramtoexecuteatadeterministicrateweneedtoputthatpartoftheprograminaperiodictask.
Objective2-Effectsofscanrateandpriority
7.
Letusinvestigatewhatthisprogramachieves.Notethattheroutine“Master”controlsthenestingtotheotherroutinesthatyouseebelow.
8.
DoubleClickandopenthe“Master”routine.Youwillnoticethatthisroutineexecutestheentireprograminthreesections:
Sequencing,MixingandAuxiliaryoperations.
Youcanrightclickoneachofthesubroutinestocheckthecross-reference.
WewillassumethatitisveryimportanttoexecutethesectionsMixingandSequencingfasterthen4000microseconds.
9.Toachievedeterminismwedividethisprogramintotwoperiodictasksinthenextsection.
PeriodicTasks
TaskModelinControlLogix
Objective2-Effectsofscanrateandpriority
TosaveontimeloadtheApplicationProgramnamedPVCCompounding_MultiProgramandmovetopoint19
10.TocreateClickontaskandrightclick,Navigateto[NewTask].Provideataskname(MixingOperation)andsayOK.
11.Similarlycreateanothertaskcalledsequencing.
12.NowgotothejustcreatedtaskcalledMixing_OperationandrightclickandnavigatetoNewProgram.ProvideanametotheprogramMixer_Section1_B.NowgobacktothecreatedtaskcalledmixingoperationandcreateanotherprogramcallitMixer_Section2_B.
13.CreateaprogramcalledIO_Section_1undertheperiodictaskMixing_Operation.
14.Nowremovetheassignedroutinefromthemainprogrambyrightclickingonthemainprogramandselecting<
none>
15.
Nowdragonesubroutineatatimeandputthemintorespectiveprogramsintheperiodictasks.Onceyoucompletethis,yourorganizershouldlooklikethis.
16.DeletethesubroutinecalledMaster.
17.Gotothemainprogramandrightclickandgotoproperties.Nowclickontheconfigurationtab.AsianthemainroutineastheMixer1.
18.Similarlyontheassignthefirstroutinestothemaininalltheprograms.
∙Mixing_Section1_BwithMix1_B4_Seq
∙I_O_Section1withA1_Seq
19.DownLoadtheprogramandGoOnLine.
FACT:
TheLogix5550providetheabilitytocreateupto32tasks
oneContinuosand31Periodic
Aperiodictaskcanbeconfiguredtoexecuteaslowas1mSec.Eventhoughthetaskistriggeredat1mstheoperatingsystemcausessomedelaybeforegivingthecontrolover.
AttheendofeachprogramtheoperatingsystemperformsanupdateofIOwhichtakessomeextraprocessingtime.
20.PullouttheformcalledTaskModelWorksheet3filedattheendofthislab.
21.NowrightclickonthemaintaskandnavigatetopropertiesandselecttheconfigurationTab.Similarlyopentheconfigurationtabsoftheothertwoperiodictasks.Arrangethemonthescreen.Yourscreenwilllooklikethis.
22.Setthepriorityofthemixingoperationtaskas1.Andthenchangetherateto1.5ms.
23.Monitortheeffectontheothertwotasks.RecordyourobservationsonTaskModelWorksheet3(onthenextpage).Forthevariousoptionsprintedintheformrecordyourobservations
24.Co-relateyourobservationstoyourunderstandingofthetaskmodel.
25.Engageageneraldiscussionwithyourpartnersandtheclasswiththehelpofyourinstructorontherecordedresults.
TASKMODELWORKSHEET3
MainTask
Sequencing
MixingOperations
LastScan
Priority
PeriodicRate
MaxRate
LastSan
1.5
3.7
Objective2-Effectsofscanrateandpriority
Usingperiodictaskwecanrunasectionoftheplantoraportionoftheprogramatapreconfigureddeterministicrate.
Thisaddsdeterminismandmodularityintheprogram.
Objective3-EffectofadditionalProgramonScanTime
TosavetimepleaseloadtheprogramPVCcompoundingLab1applicationprogram
1.NowgotothecreatedtaskcalledMixingOperationandrightclickandnavigatetoNewProgram.ProvideanametotheprogramMixer_Section2_B.
Assignthefirstroutinestothemaininalltheprogram.
∙Mixing_Section2_BwithMix2_B4_Seq
2.Theorganizershouldappearasshownabove.
Objective3-EffectofadditionalProgra
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- CLXtipsTask
![提示](https://static.bdocx.com/images/bang_tan.gif)