LG Electronics K4F-PIDA, K7F-PIDA manual Specifications Derivative Action D Action

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Chapter 2. SPECIFICATIONS

3)Derivative Action (D Action)

(1)When a deviation occurs due to alteration of SV or external disturbances, D action restrains the changes of the deviation by producing MV which is proportioned with the change velocity (a velocity whose deviation changes at every constant interval) in order to eliminate the deviation.

!D action gives quick response to control action and has an effect to reduce swiftly the deviation by applying a large control action (in the direction that the deviation will be eliminated) at the earlier time that the deviation occurs.

!D action can prevent the large changes of control object due to external conditions.

(2)The period of time from when the deviation has occurred to when the MV of D action become the MV of P action is called derivative time and represented as Kd.

(3)The D action when a given deviation occurred is shown as Fig. 2.7.

[Fig. 2.7] Derivative action at a constant deviation

(4) The expression of D action is represented as follows:

!In this expression, an output proportional with the variation rate of deviation is added to P action quantity. !If the derivative time is increased then P action is strengthened.

!D action is applied when a change of deviation occurs and the deviation at normal state become 0. D action, therefore, do not reduce offset.

(5)D action is used in either PD action in which P action combines with D action or PID action in which P and I actions combine with D action.

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Contents User’s Manual Contents Buffer Memory Configuration and Functions Functions of Buffer MemoryDimensions TroubleshootingProgramming Safety Precautions Waste Disposal Precautions Introduction IntroductionSpecifications General SpecificationsSpecifications General specificationsItems Specifications Performance SpecificationsTable .2 Performance Specifications Names of Parts and Functions DescriptionsPID Control Action Specifications Control Action Proportional Action P Action MV = Kp E When the proportional constant Kp is large Specifications Integral Action I Aaction Integral action at a constant deviationWhen a long integration time is given Specifications Derivative Action D Action Derivative action at a constant deviationIntegral constant Specifications PID Action+ K p S/K I E n Derivative constant Control cycle 100 ms Specifications Forward/Reverse Actions Forward and reverse action with MV, PV and SVInstallation Installation AmbienceHandling Precautions InstallationBuffer memory Configuration Buffer Memory Configuration and FunctionsBuffer Memory Configuration and Functions Read Functions of Buffer Memory Specifying Auto/Manual Processing K7F-PIDA Addresses 2Specifying SET Data Enable/Disable K7F-PIDA Addresses 6 Etting PID Control Data Address 10 decimalThis area stores the MV of each loop MV output range is 0 to Read from Buffer Memory ⋅ ⋅ ⋅ GET, Getp Write to Buffer Memory ⋅ ⋅ ⋅ PUT, Putp Difference between PUT and PutpProgramming Basic ProgrammingProgramming 1 K7F-PIDAProgramming 2 K4F-PIDA Application Programming Initial SettingsDescriptions of the Program Modules and their Signal Processing Conversion Module initialization Switch RD3A Pida AD4A RTD input module Power conversion device TC K type SV 200.0 C Programming Errors Indicated by RUN LED Flickering TroubleshootingTroubleshooting Procedure Run LED of enabled Loops Off Is RUN LED turned OFF? PID Control Module Hardware DefectK7F-PIDA Dimensions DimensionsDimensions K4F-PIDA Dimensions