YOKOGAWA UT55A - 7.7 Setting PV Switching Methods

7-18
IM 05P01C31-01EN
7.7 SettingPVSwitchingMethodsofLoopControl
withPVSwitching
Description
PVswitchingmethodofLoopcontrolwithPVswitchingcanbesetwhenthecontrol
modeisLoop
controlwithPVswitching.
► BlockdiagramofLoopcontrolwithPVswitching:8.1.6LoopControlwithPVSwitching,
Heating/coolingLoopControlwithPVSwitching,andPositionProportionalLoopControlwithPV
Switching
Input1:PVterminalinput
Input 2: RSP terminal input
SwitchingwithintheTemperatureRange(Low-temperatureside)(ParameterPV.2C=0)
ThismethodautomaticallyswitchesPVwithintherangeofinputswitchingPVhighlimit
and low limit.
Itshouldbe
selectedincasewhereasuddenchangeinPVmustbeavoided.
PVrisingprocess
PV.HL
PV.LL
Input 2
(High-temperature side)
PV
Time
PV = Input 1 PV = Input 2During switching
Input 1
(Low-temperature side)
PVfallingprocess
PV.HL
PV.LL
Input 2
(High-temperature side)
PV
Time
PV = Input 2 PV = Input 1During switching
Input 1
(Low-temperature side)
Wheninput1≤PV.LL,PV=Input1.
WhenPV.LL<Input1<PV.HL
1
Input 1
PV
–
+
Input 2
=
PV.HL – PV.LL
Input 1 – PV.LL
Input 1 – PV.LL
PV.HL – PV.LL
• •
WhenPV.HL≤Input1,PV=Input2.