如何实现过程变量平均值归档

SIMATICWinCCOptionen/Powerpacks SIMATICWinCCSoftware PCS7OS(Bundle), SIMATICPCS7SW-Packages(BLE,ES,在变量归档编辑器中，用户可以通过打开"Processtagproperties"对话框，在"Processing"的"Parameters"页面中选择"Meanvalue"(38KB图1“10的跳变情况。计算出的平均值与相关的当前过程值之间存2“对应的过程值为0％。则过程变量的平均值计算如下：8*02*1003“周期对应的过程值为0％。则过程变量的平均值计算如下：8*02*1004“期对应的过程值为100％。则过程变量的平均值计算如下：8*1002*0(120KB图条目号: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