YOKOGAWA UT55A - Page 300

12-3
IM 05P01C31-01EN
ContactInput/OutputFunctions
12
PVHold(PVHD)
PVcanbeheldusingcontactinput.(Statusswitch)
Contact status Operation Remark
ON SwitchestoMAN,
holdsPV
AUTO/MAN switch by keystroke or via
communicationisdisabled.HoldsthePVstatus.
OFF Switches to AUTO
AUTO/MAN switch by keystroke or via
communication is enabled.
Canbeused
inLoopcontrolwithPV-holdfunction.
LatchRelease(LAT)
Latch can be released using contact input. (Switch by the rising edge)
Contact status Operation Remark
OFF→ON Releases the latch –
ON→OFF Maintains the current operation status –
Releasing the latch function releases all latched contact (alarm) outputs.
LCDBacklightON/OFFSwitch(LCD)
LCD backlight ON/OFF can be switched using contact input. (Switch by the rising edge
and the falling edge)
Contact status Operation Remark
OFF→ON Turns off the LCD backlight –
ON→OFF Turns on the LCD backlight –
CAStoAUTOSwitch(CTOA)
The mode is switched from CAS to AUTO when the primary-side controller fails. (Status
switch) CAS to AUTO Switch can be set when the control mode (CTLM) is Cascade
secondary-loop control.
Contact status Operation Remark
ON Does not work. –
OFF
Switches to AUTO when the operation
mode is CAS (cascade).
AUTO/MAN switch by keystroke or via
communication is enabled.
MessageDisplayInterruption1to4(MG1to4)
The message set using LL50A Parameter Setting Software can be interrupt-displayed on
PVdisplayusingcontactinput.Themessagesarelimitedto20alphanumericcharacters.
A maximum of four displays can be registered. (Switch by the rising edge)
► Message:LL50AParameterSettingSoftwareUser’sManual
Contact status Operation Remark
OFF→ON Interrupt-displays the message Pressing the DISPLAY key erases the message.
ON→OFF DisplaysthecurrentPV –
PVRed/whiteSwitch(PVRW)
PVcolorcanbeswitchedusingcontactinput.(Statusswitch)
Contact status Operation Remark
ON Red color –
OFF White color –
Set "10" to the parameter PCMD.
12.1 Setting Contact Input Function