The Application Of Real-time Operating System In Astronomic Fast Readout CCD

In the area of astronomy, at the field where requiring time resolution, video CCD is used. But the inevitable disadvantage of video CCD is gradually exposured while the research work goes deeply. The fast readout CCD system which is developed by Yunnan observatory , with 10frames/s readout rate, 12 bits AD depth, 1000* 1000pixels active area, establishes the base for image rebuilding, fast rate image acquisition, image quality testing, wave-front detecting, etc. This CCD system requires to shoot a great deal of images in thumbnail time, then these images should be transferred to computer. Data transfer rate reaches 20Mbps. And these images should be simultaneously displayed and stored. So the performance of the corresponding processing software is very important for the whole CCD system.In this paper, we first analyze all the indices of fast readout CCD system. After evaluating the characters of various operating system, we decide to choose QNX real-time/embedded system as the OS for fast CCD system. The preliminary design of software system function is given in this paper, and parts of it have been achieved. We will complete the whole system in the future.The paper has five parts. In the first chapter, the whole fast readout CCD system and background of relative research are introduced. In the second chapter, the reasons of choosing QNX as our operating system is given out. We also describe the operation theory of digital I/O board PCI-7300A and the interface between CCD hardware and 7300 card. The preliminary structure of software system is explained in detail in the third chapter. In the forth chapter, results of the complete work are shown, including the initialization of system and the function of two work modes. The last part outline our future work briefly.