PA7300 Instruction Manual - TECO-Westinghouse Motor Company

c How to adjustThe PID control function is a control system that matches a feedback value (ie.,a detected value) to the aimed value. Combining P (Proportional, Bn-14), I(Integral, Bn-15), and D (Derivated, Bn-16) makes control possible even for amechanical system with dead time. The PID control function, using differentdetected sensors, can be used for speed, pressure. flow or temperature etc.applications.(1) PID control operations.In order to distinguish the separate PID control operations. The figure belowshown the changes in the control input when the deviation between the targetvalue and the feed back is held constant.DeviationTimeControl inputD controlPID controlI controlP controlTimeFig. 14 PID Control OperationsP Control:I Control:A control input proportional to the deviation is output. The deviationcannot be zeroed by P control alone.A control input which is an integral of the deviation is output. This iseffective for matching the feedback to the target value. Suddenchanges, however, cannot be followed.D Control: A control input which is an integral of the deviation is output. Quickresponse to sudded changes is possible.PID Control: Optimum control is achieved by combining the best features of P, I, andD control.123