Motion Control with the Parallel Port on PC and Its Application

The programming method to control a stepper motor or a servo motor using a parallel port is described. This procedure enables control of a motor using the high resolution performance counter with accuracy exceeding 1 microsecond on most hardware of PC and the algorithm for motion control not have any additional hardware for motion control such as PCI motion control card. The procedure for control of trapezoidal motion is explained in detail here for acceleration, constant speed and deceleration processes written in Visual C++. The frequency variation range of pulses from the parallel port is from 0 to 40 kHz under Windows XP and every period of pulses is controlled according to a given acceleration or speed value. This procedure has been applied to control the motion of a turntable for Nd:YAG laser welding of Li ion secondary batteries.