H134-E1-01A E5_N UsersManual (986777), страница 20
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(The loop break alarm will remain OFF.)If the process value is outside the LBA level between 4 and 5 and the controldeviation is not reduced by at least the LBA band within the LBA detectiontime, the loop break alarm will turn ON.If the control deviation is reduced in the area between 5 and 6 (i.e., the setpoint is approached) and the amount the control deviation is reduced is atleast equal to the LBA band, the loop break alarm will turn OFF.If the control deviation is reduced in the area between 6 and 7 (i.e., the setpoint is approached) and the amount the control deviation is reduced is lessthan the LBA band, the loop break alarm will turn ON.• If the LBA detection time, LBA level, LBA detection band, and PID settings are not appropriate, alarms may be detected inappropriately oralarms may not be output when necessary.• Loop break alarms may be detected if unexpectedly large disturbancesoccur continuously and a large deviation does not decrease.• If a loop break occurs when the set point is near the ambient temperature,the temperature deviation in a steady state may be less than the LBAlevel, preventing detection of the loop break.• If the set point is so high or low that it cannot be reached even with a saturated manipulated variable, a temperature deviation may remain even ina steady state and a loop break may be detected.94Section 4-12Loop Break Alarm• Detection in not possible if a fault occurs that causes an increase in temperature while control is being applied to increase the temperature (e.g.,an SSR short-circuit fault).• Detection in not possible if a fault occurs that causes a decrease in temperature while control is being applied to decrease the temperature (e.g.,a heater burnout fault).Parameters Related to Loop Break AlarmsParameter nameSymbolSetting rangeRemarksLBA detection timelba0 to 9999 (s)LBA levellbalControllers with Thermocouple/Resistance Thermometer Multi-inputs0.1 to 999.9 (°C/°F) (Seenote.)Default: 8.0 (°C/°F)Controllers with AnalogInputs0.01 to 99.99 (%FS)Default: 10.00% FSControllers with Thermocouple/Resistance Thermometer Multi-inputs0.0 to 999.9 (°C/°F) (Seenote.)Default: 3.0 (°C/°F)Controllers with AnalogInputs0.00 to 99.99 (%FS)Default: 0.20% FSLBA bandlbabNoteSetting 0 disables the LBAfunction.Set “none” as the unit for analog inputs.• A loop break alarm can be output by setting the alarm 1 type to 12 (LBA).• The ALM1 indicator will light when a loop break is detected.• Loop breaks are not detected during SP ramp operation.• Loop breaks are not detected during auto-tuning, manual operation, orwhile stopped.• If the alarm 1 latch is set to ON, the latch will be effective for the loopbreak alarm.Automatically Settingthe LBA DetectionTime• The LBA detection time is automatically set by auto-tuning.(It is not set automatically, however, for heating/cooling control.)Determining the LBADetection Time• To manually set the LBA detection time, set the “LBA detection time”parameter to twice the LBA reference time given below.1,2,3...• If the optimum LBA detection time is not obtained by auto-tuning, set the“LBA detection time” parameter (advance function setting level).1.
Set the output to the maximum value.2. Measure the time required for the width of change in the input to reach theLBA band.TemperatureMeasurement timeTmPVLBA bandMV = 100%TimeLBA detection time = Tm × 295Section 4-12Loop Break Alarm3.
Set the “LBA detection time” parameter to two times the measured time.LBA Level• Set the control deviation when the control loop is working properly.• The default is 8.0 (°C/°F) for Controllers with Thermocouple/ResistanceThermometer Multi-Inputs and 10.00% FS for Controllers with AnalogInputs.LBA Band• There is assumed to be an error in the control loop if the control deviationis greater than the threshold set in the “LBA level” parameter and if thecontrol deviation does not change by at least the value set in the “LBAband” parameter.• The default is 3.0 (°C/°F) for Controllers with Thermocouple/ResistanceThermometer Multi-Inputs and 0.20% FS for Controllers with AnalogInputs.Operating ProcedurePerform the following procedure to use the loop break alarm.In this example, the LBA detection time is set to 10, the LBA level is set to 8.0,and the LBA band is set to 3.0.Operation LevelC25PV/SP100Initial Setting Levelin-tInput type1.
Press the O key for at least three seconds to move from the operationlevel to the initial setting level.5Initial Setting Levelalt12. Select the “alarm 1 type” parameter by pressing the M key.Alarm 1 type2Initial Setting Level3. Press the U key to set the parameter to 12.alt112amov0Move to advanced functionsetting levelAdvanced Function Setting LevelinitParameterinitialization4. Select the “move to advanced function setting level” parameter by pressing the M key.5.
Press the D key to enter the password (−169), and move from the initialsetting level to the advanced function setting level.offAdvanced Function Setting LevelLBA detectionlba time0966. Select the “LBA detection time” parameter by pressing the M key.Section 4-13Performing Manual ControlC7. Press the U key to set the parameter to 10.lba10Advanced Function Setting LevelClbal8.
Select the “LBA level” parameter by pressing the M key.LBA level8.0C9. Press the U key to set the parameter to 8.0. (The default is 8.0.)lbal8.0Advanced Function Setting LevelClbab10. Select the “LBA band” parameter by pressing the M key.LBA band3.0C11. Press the U or D key to set the parameter to 3.0. (The default is 3.0.)lbab3.0Input type12.
Press the O key for at least one second to move from the advanced function setting level to the initial setting level.PV/SP13. Press the O key for at least one second to move from the initial settinglevel to the operation level.Initial Setting Levelin-t5Operation LevelC251004-13 Performing Manual Control4-13-1 Manual Operation• The manipulated variable can be set in manual mode if the “PV/MV”parameter is displayed in the manual control level. The final MV used inautomatic mode will be used as the initial manual MV when moving fromautomatic mode to manual mode. In manual mode, the change value willbe fixed immediately and reflected in the actual MV.• The automatic display return function will not operate in manual mode.• Balanceless-bumpless operation will be performed for the MV whenswitching from manual operation to automatic operation.
(See note.)• If a power interruption occurs during manual operation, manual operationwill be restarted when power is restored using the same MV as whenpower was interrupted.• Switching between automatic and manual operation is possible for a maximum of one million times.• Manual operation can be used only for PID control.97Section 4-13Performing Manual ControlNoteIn balanceless-bumpless operation, the MV before switching is used initiallyafter the switch and then gradually changed to achieve the proper value afterswitch to prevent radical changes in the MV after switching operation.The overall manual operation is illustrated in the following figure.MV (%)Balanceless-bumplessTime0ManualMV switchedOFFONPower interruptedAutomaticRelated Displays and ParametersParameter namePV/MV (manual MV)Symbol---LevelManual Control LevelAuto/manual switcha-mOperation LevelAuto/manual select additionamadAdvanced Function SettingLevelNoteMoving to the ManualControl Level98Remarks−5.0 to 105.0 (heating/cooling control: −105.0 to105.0)Switches between automatic and manualmodes.Enables switching between automatic and manual modes.Refer to 4-16 Output Adjustment Functions for information on the priority forthe MV.• When the O key is pressed for at least 3 seconds in the operation level'sauto/manual switching display, the manual mode will be entered and themanual control level will be displayed.
It is not possible to move to any displays except for the “PV/MV” parameter during manual operation. Pressthe O key for at least one section from the “PV/MV” display in manualcontrol level to return to automatic mode and display the top parameter inthe operation level.Section 4-13Performing Manual ControlOperation LevelCPress O key for at least 1 s.25PVMC25PV/SP100Manual Control LevelMC2520PV/MVa-mPress O key for at least3 s.a-m display flashes forat least 1 s.a-mAuto/manual switchMm-spMulti-SP0M• If an event input is set to “MANU” (auto/manual), the “auto/manual switch”parameter will not be displayed.
Use the event input to switch betweenautomatic and manual modes.Auto/Manual SelectAdditionNote• The “auto/manual select addition” parameter must be set to ON in theadvance function setting level before it is possible to move to manualmode. The default is OFF.(1) Priority of Manual MV and Other FunctionsEven when operation is stopped, the manual MV is given priority.Auto-tuning and self-tuning will stop when manual mode is entered.(2) Manual MV and SP RampIf operating, the SP ramp function will continue even when manual modeis entered.99Section 4-13Performing Manual ControlOperating ProcedureUse the following procedure to set the manipulated variable in manual mode.Operation LevelC25PV/SP100Initial Setting Levelin-tInput type1.
Press the O key for at least three seconds to move from the operationlevel to the initial setting level.52. Select the “PID ON/OFF” parameter by pressing the M key.cntlpidInitial Setting LevelMove to ad-functionamov vancedsetting level3. Select the “move to advanced function setting level” parameter by pressing the M key.0Advanced Function Setting LevelParameterinit initialization4. Press the D key to enter the password (−169), and move from the initialsetting level to the advanced function setting level.offAdvanced Function Setting LevelAuto/manualamad select addition5.
Select the “auto/manual select addition” parameter by pressing the Mkey.off6. Use the U key to set the parameter to ON.amadonInitial Setting Levelin-tInput type7. Press the O key for at least one second to move from the advanced function setting level to the initial setting level.58.
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