Easy Electronics xLogic Micro PLC - Page 155

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Q=1,if(actualvalueAx-actualvalueAy)>On
Q=0,if(actualvalueAx-actualvalueAy) ≤Off.
• IfthresholdOn<ThresholdOff,thenQ=1,falls:
On ≤ (actualvalueAx-actualvalueAy)<Off.
Reducingtheinputsensitivityoftheanalogcomparator
Youcandelaytheoutputoftheanalogcomparatorselectivelybymeansofthe"ondelay"and"offdelay"
SFBs.Bydoingso,youdeterminethatoutputQisonlysetiftheinputtriggerlengthTrg(=outputofthe
analogcomparator)exceedsthedefinedondelaytime.
Thiswayyoucansetavirtualhysteresis,whichrenderstheinputlesssensitivetoshortchanges.
Particularcharacteristicstobenotedwhenconfiguring
Forhelponanalogblockparameters,refertotheAnalogvalueprocessingsectioninxLogicsoft.
SettingtheParparameter
Thegainandoffsetparametersareusedtoadaptthesensorstotherelevantapplication.
Viewinprogrammingmode:
Example
Inaheatingcontrolsystem,thesupplyTvandreturnlinetemperaturesTraretobe
compared,forexamplewithasensoratAI2.
Acontrolsignalistobetriggered(forexample"heaterOn")whenthedifferencebetweenthe
supplyandreturnlinetemperaturesisgreaterthan15 °C.Thecontrolsignalisresetwhen
thedifferenceislessthan5°C.
Theprocessvariableofthetemperatureistobeshowninparameterassignmentmode.
Thethermocouplesavailablehavethefollowingtechnicaldata:-30to+70 °C,0to10VDC.