如何實(shí)現(xiàn)過程變量平均值歸檔

SIMATICWinCCOptionen/Powerpacks SIMATICWinCCSoftware PCS7OS(Bundle), SIMATICPCS7SW-Packages(BLE,ES,在變量歸檔編輯器中，用戶可以通過打開"Processtagproperties"對(duì)話框，在"Processing"的"Parameters"頁面中選擇"Meanvalue"(38KB圖1“10的跳變情況。計(jì)算出的平均值與相關(guān)的當(dāng)前過程值之間存2“對(duì)應(yīng)的過程值為0％。則過程變量的平均值計(jì)算如下：8*02*1003“周期對(duì)應(yīng)的過程值為0％。則過程變量的平均值計(jì)算如下：8*02*1004“期對(duì)應(yīng)的過程值為100％。則過程變量的平均值計(jì)算如下：8*1002*0(120KB圖條目號(hào):24050680日期:2006-11-Howisthemeanvalueforprocessvariablesstoredintheprocessvaluearchive? Displaypartnumber SIMATICWinCCOptionen/Powerpacks SIMATICWinCCSoftware PCS7OS(Bundle), SIMATICPCS7SW-Packages(BLE,ES,YoucanusetheTagLoggingeditortodefineanarchivevariableinsuchawaythatitsmeanvalueissavedinthearchive.Thisisdonebyopeningthe"Processtagproperties"dialogboxandselectingthe"Meanvalue"selectionfieldinthe"Parameters"tabunder"Processing".Themeanvaluecanonlybeformedinthecaseof"Cyclic-continuous"or"Cyclic-selective"typeacquisitions.Themeanvalueiscalculatedfromthearithmeticmeanoftherecordedprocessvalueswithinthearchiving/displaycycle.Intheeventthatarchivingonlyoccurswhenchangesaremade,occasionallytheremaybeasignificantdiscrepancybetweenthecurrentprocessvalueandthearchivedvalue.Thefollowingfigureillustratesdifferentexamples:Theexamplesaredescribedinthetablebelow.(38KBFig.1Thisexampleillustratesaone-offsuddenchangeinaprocessvalue.Themeanvaluecalculateddeviatesrelativelysharplyfromthecurrentprocessvaluebecausetherehasbeenasuddenchangeintheprocessvaluewithinthearchivingcycle.However,themeanvalueisnotrecalculatedorsavedinthefollowingarchivingcyclesincethehysteresissettinghasnotbeenexceeded.Themeanvalueisonlyrecalculatedandsavediftheprocessvalueexceedsthehysteresislimitsagain.2Thearchivingcycleistentimestheacquisitioncycle.Theprocessvaluefortwooftheacquisitioncyclesis100%,and0%fortheremainingeightacquisitioncycles.Thisgivesrisetothefollowingarithmeticmeanvalue:Meanvalue=(8*0%+2*100%)/Meanvalue=203Thearchivingcycleistentimestheacquisitioncycle.Theprocessvalueforthelastacquisitioncyclesis100%,and0%forthefirsteightacquisitioncycles.Thisgivesrisetothefollowingarithmeticmeanvalue:Meanvalue=(8*0%+2*100%)/Meanvalue=204Thearchivingcycleistentimestheacquisitioncycle.Theprocessvalueforthefirsttwoacquisitioncyclesis0%,and100%fortheremainingeightacquisitioncycles.Thisgivesrisetothefollowingarithmeticmeanvalue:Meanvalue=(8*0%+2*100%)/Meanvalue=80Thispatternisborneoutbythefigurebelow.Aprocessvariablehasbeensavedinarchiveswithidenticalacquisitioncyclesanddifferentarchivingcycles.Archivingonlyoccurredinallcaseswhenchangesoccurred.Theabsolutehysteresisineachcasewas"1.0".Theessentialarchivingparameter