Abstract- In industries, the control of direct current (DC) motor is a common practice thus the implementation of DC motor of speed control is important. The main purpose of motor speed control is to keep the rotation of the motor at the preset speed and to drive a system at the demanded speed. When used in speed application, speed feedback control the DC motor's speed or confirms that the motor is rotating at the desired speed. To maintain the speed, it requires the speed feedback at all times. The speed of a DC motor usually is directly proportional to the supply voltage. For instance, if we reduce supply voltage from 5 Volts to 2.5 Volts the motor will run at half or lower the speed. The advantages used DC motor is provide excellent speed control for acceleration and deceleration with effective simple torque control. This paper considers the method that are used to control speed of DC motor is phase locked loop (PLL) with proportional and data acquisition system (DAS) based to monitor the dynamic of the system and predict the change of stability for system. In this project, the method use to indicate how far the system from instability and take the reaction rapidly before system goes to unstable and to be out of control and problems occur in the rest of dependable parts on that system and useful for preventive maintenance which effective approach for reliability enhancement for the system so a failure can be detected early or even predicted is the key point. This project presents a failure prediction method for help in preventive maintenance with rapid indication for system stability and design via bode diagram to get phase margin and gain margin by program (G-code) on LabVIEW before system operations .