Study Of Laser Marking Control System Based On DSP &CPLD

With the development of laser technology, the application of laser marking has become wider and wider. However, the improvement of technique that is related to laser marking has brought out higher requirement for laser marking technology, especially the flying laser mark. In some special occasions, it is not only required to have higher precision and better effect, but also higher speed for higher productivity. In this thesis, the structure and principle of present laser marking system have been analyzed. And the decision to research and develop a new type of control card has been made. After studying the advanced automation technology; both Digital Signal Processor (DSP) and Complex Programmable Logic Device (CPLD) are proposed to be used in the design of new control card for laser marking system.This design is based on TMS320LF2407A from TI Corporation. And the powerful resource of DSP has been used to produce Pluse-Width Modulation (PWM), in this way, the frequency and duty cycle can be adjusted conveniently and promptly by the computer. This design has greatly expanded the application range of laser marking, the real-time ability and flexibility of power control. Besides, DSP is also used to process the digital signal from the encoder and then transfer the result to the Computer in the aim of improving the control precision of the scanner and obtaining a better marking result. In addition, CPLD has been used in this system to design some digital logic circuit, such as the decoding circuit, bus controlling circuit and gates. The introduction of CPLD has simplified the circuit greatly, and made the circuit design more flexible.Then, the software developing tools for DSP and CPLD have been explained and the procedures of programming for DSP and CPLD have been specified.some program has been listed here.Finally, the schematic circuit diagram and PCB design has been introduced and testing has been finished. Some results are displayed in the final part and some suggestion on how to improve the card has been given in the last part of this thesis.