The Design Of Data Acquisition System And PC Application Software For CCD Photoelectric Signal

CCD (Charge Coupled Device) technology and related applications have been made considerable progress since it was proposed by the Bell Labs conceptually in 1969, especially in the image sensor and non-contact measurement area. CCD photoelectric detection technology can provide a reliable and secure protection for modern high-speed railway system, due to its high precision, high speed and non-contact measurement.In this work, a high-speed analog to digital conversion module, which can be applied in CCD photoelectric detection system, is designed. This can convert tow 4-MHz analog CCD sensor signals to 12-bit digital signals at the conversion rate of 8-MHz. The mainly content of this work includes:Firstly, a CCD photoelectric detection hardware system is introduced, and it mainly consists of CCD driving module, analog signal differential amplifying module, analog to digital conversion (ADC) module, CPLD (Complex Programmable Logic Device) programmable module, and FIFO (First Input First Output) high-speed cache module and USB2.0 high-speed transmission module. Detailed description of design and function for differential amplifying module, analog to digital module, CPLD programmable module and FIFO high-speed cache module is presented. Meanwhile, the printed circuit board for these four functional modules is designed utilizing the Protel 99se software.Then, some CPLD internal module program is designed under the QuartusⅡplatform, aiming to achieve the configuration for analog to digital conversion chip THS12082 and FIFO cache chip, including setting the THS12082 at the sampling rate of 8-MHz, choosing the work mode, bus width and data storage mode for the FIFO cache chip. In addition, Windows-based PC (personal computer) application software is developed under the Visual C++ 6.0 platform. By calling the CyAPI library function, hardware system control, measured data collection, transmission, storage and waveform display in the personal computer are realized.Finally, a corresponding test system is built up. The experimental results show that our system can measure the displacement for the objects accurately. Under the control of application program, the measured data can be delivered to the personal computer through the USB interface correctly, and data save, virtual waveform display for measured results are realized as well.