Algorithm, PHP, iPhone, of the most common examples of the algorithm of feedback control is that in many of the processes of control such as speed control DC motor, control pressure, control temperature and ... application. The goal of the algorithm of PID in closed loop control, control is accurate and fast output of the system under different conditions and without knowing the exact behavior of the system in response to the input. PID of the three distinct parts to the name, Proportional (proportionality), the Integral (integral) and Drivative (derivative) formed when each of the mentioned signal error as the input is taken and operational) are doing, and finally output their together. The output of this set is the same as the output of the PID is to correct the Error (error) to the system will be sent.