The stepper motor can only be operated by digital signals. When the pulse is provided to the driver, the control system announces too many pulses in too short a time, namely, the pulse frequency is too high, which will cause the stepper motor to stall. To solve this problem, it is necessary to adopt the method of acceleration and deceleration. That is to say, when the stepper motor start, to gradually increase the pulse frequency, the deceleration pulse frequency demand gradually reduced. This is often referred to as "acceleration and deceleration" method.