YOKOGAWA UT55A - Loop Control with PV-Hold Function, Heating;Cooling Loop Control with PV-Hold Function, and Position Proportional Loop Control with PV-Hold Function

8-61
IM 05P01C31-01EN
Control Functions
8.1.8 LoopControlwithPV-holdFunction,Heating/coolingLoopControlwith
PV-holdFunction,andPositionProportionalLoopControlwithPV-hold
Function
Setting Details
Parameter
symbol
Name
Display
level
Setting range Menusymbol
CTLM Control mode STD
SGL: Single-loop control
CAS1: Cascade primary-loop
control
CAS2: Cascade secondary-loop
control
CAS: Cascade control
BUM: Loop control for backup
PVSW:LoopcontrolwithPVswitching
P VSEL:LoopcontrolwithPVauto-
selecto r
PVHD:LoopcontrolwithPV-hold
function
CTL
 CAUTION
• Someparameterswillbeinitializedifthecontrolmode(CTLM)ischanged.
• When using the ladder program, the control mode cannot be changed.
Description
ThesecontrolmodesholdthePVinputvalueandcontroloutputvaluebyswitchingthe
external sensor using contact input.
Loop
controlwith
PV-holdfunctioncanbeusedforStandardtypeorHeating/coolingtype
controller.
Heating/coolingloopcontrolwithPV-holdfunctioncanbeusedforHeating/coolingtype
controller.
Positionproportionalloop
controlwithPV-holdfunctioncanbeusedforPosition
proportional type controller.
► PIDcontrolandHeating/coolingcontrol:8.2SettingControlType(CNT)
Uptofour10-segmentlinearizerapproximation/10-segmentlinearizerbiasescanbe
used for the input unit or output unit.
The Function block diagram describes only the basic functions.
Parameter symbols in the Function block diagram describe representative parameters.
For the functions and parameters which are not described in Function block diagram, see
the following.
► Contactinputassignment:12.1SettingContactInputFunction
► Contactoutputassignment:12.2SettingContactOutputFunction
► Contactoutputassignmenttoretransmissionoutputterminal:10.1SettingControlOutputType
► Analogoutputrangechange:10.14ChangingCurrentOutputRange
8
8.1SettingControlMode(CTLM)