Design And Implementation Of High Speed Virtual Oscilloscope Based On USB2.0

As the innovation of electronic science and technology, electronic instruments have developed rapidly and gone through different development processes from the analog, digital, and intelligent stage to the virtual stage. To be one of the most important electronic instruments, oscilloscope is becoming more and more virtualized.Virtual instrument simplifies the traditional hardware structure with the computer software to achieve some of the hardware functions, which reduce the cost of the instrument and upgrade the common computer to specific electronic devices. But it is too complicated to install traditional virtual instruments that connect PC with GPIB, PCI and RS232 etc, which make the implementation of virtual instruments less flexible. The USB based virtual instrument combines the portability of high-speed USB with the excellent performance of computer by sampling and converting analog signal to digital signal with hardware, transmitting digital signal to computer with USB, and eventually analyzing the signal in the computer, which has the advantages such as convenient installation, good flexibility, plug and play and is very prospective.In the beginning, this paper discusses the basic conception and prospect of virtual instrument. Then by analyzing the structure, principle and function of digital oscilloscope, we propose a design blue print of virtual oscilloscope and set the role of hardware and software, designs and implements a virtual oscilloscope based on USB 2.0 consisting of data acquisition hardware and operational software. After that, it gives the specific design of hardware, which includes signal modulate, A/D conversion, data storage, transmission with USB and the date control modules. Finally, it achieves the design of software used on the designed oscilloscope that can not only display waveform as traditional oscilloscope does, but also have the functions of spectrum analysis and data computation.The results show that the designed virtual oscilloscope could complete the required function, and is up to design standard basically.