Designing Of Data Acquisition System Based On USB

With the developing of railroading, more and more people pay attention to the security of railway. So the analysis on railway tracks data becames more and important. The subject is mainly concerned with the developing of railway track data acquisition system. Based on USB (Universal Serial Bus) technology and multithreading technology, the entire process is completed, including the design of hardware, developing of software, the conformity and debugging of sofeware and hardware ,implementing the collection of railway track signalsFirstly, in the paper, the basic principle and configuration of USB are introduced simply. Because of low cost, simplifies and PnP (Plug and Play), USB has been widely used in PC and Embedded System field.Secondly, the modular is a very efficient way to design the circuit. According to the work flow, the entire system can be divided into six blocks: signal modulate module, data acquisition module, data buffering module, logic controlling module, USB interface module and voltage diversion module.Thirdly, the system software is divided into three parts: the firmware of USB chip, USB device driver and operation platform. It is necessary to point out that operation platform is based on C++ Builder, which makes use of multithreading, and realizes synchronization of acquisition and display.Finally, the system's installing and debugging are accomplished, and the acquisition interface and waveform achieved from the acquisition system are illuminated. Several improvable methods are put forward after looking back on the system at the end of the paper. At the same time, the further research direction is proposed; in addition, the application future of USB data acquisition is prospected.