Research And Realization Of Shipborne Digital Programme-controlled Telephone Switching Board Based On The CAN Bus

Program-controlled telephone switching board is the warships' core equipment of the intercommunication systens, whose reliability and stability have a strong impact on the quality of the warships' inner command communication. This article is proposed to develop a new type of digit programme-controlled telephone switching board which is based upon the CAN bus to replace the old automatic telephone switchboard. Because the performances such as the voice loudness and articulation, restraining crosstalk disturbance, resisting external electromagnetism and power interference and etc is greatly better than that of the traditional simulative switching board;under the control of the high-performance processor,the new digital switching board can provide some new service functions,but the old one can't do it.CAN bus is useful to many fields of distributed multiprocessor control mode, such as automotive engine's control parts of automation electron field. But there is no report of use the CAN bus to the digit programme-controlled telephone switching board. If we can use it to the digit programme-controlled telephone switching board successfully, it will be the new use of the CAN bus.The thesis expatiate the current situation of the warships' programme-controlled telephone switching boards first ,after that, we give out the whole design plan of the new type of digital programme-controlled telephone switching board , We also analyze the design of CAN bus, switching network circuit detailedly. This paper's focus is on the application of the CAN bus and the realization of the switching board, the new switching board adopt the distributed multiprocessor control mode, digital time- division and non-blocking switching network;and adopt high-level language to design system software which can improve the reliability and the maintainability of the software system. We use the ATMEL company's DS80C320 as the central processor,and use the AT89C52 as the module processor.the control chip of the CAN bus is SJA1000 of PHILIPS company,it is a high integrated control chip ,has all necessary characteristic what high-performance communication protocol requires that.After a series of debugging and improvements, the switchboard runs stably ,all technical requirements resches the preconcerted targets. Therefore, the digital programme-controlled telephone switching board proposed in the article, can very good satisfy the operation requirements of the warships.