PLC-API The switching algorithm calculates a linear, time-dependent transition between the two parameter records. The nParameterChangeCycleTicks parameter can be used to specify the number of task cycles over which the continuous change between the two parameter records takes place. Transfer function: The following transfer function can be declared for this block, if the boolean inputs bPInTheFeedbackPath and bDInTheFeedbackPath are set to FALSE, otherwise this transfer function only describes a part of the blocks behaviour: Functional diagram:
The standard functional diagram of a PID controller in additive form has been expanded by the two active boolean inputs bPInTheFeedbackPath and bDInTheFeedbackPath (which act as "switches"), so that a modified functional diagram can be activated. Control background: due to the differential component of the control algorithm, large control values are generated at setpoint step-changes, which cause a strain on the control elements and may cause the control system to oscillate. A control algorithm with a differential component that is only applied to the controlled variable ( bDInTheFeedbackPath := TRUE ) can avoid this problem.
The bPInTheFeedbackPath and bDInTheFeedbackPath inputs permit the closed control loop to implement the following transfer functions: TS4100 72 Version: 1.1