Research And Design Of Universal Interface For Virtual Instrument

Virtual instrument(VI for short) is a new kind of electronic instrument with electronic measure technology deeply combined with computer technology, has good prospects for development, and is widely used in various fields of science and technology.USB interface is a bus interface standard. It has very high transfer rate,PnP and compatibility virtue, and has been widely applied in data transmission and image acquisition.For the data exchange issue between the virtual instrument system developed in the laboratory and computer, the paper proposes and designs the USB2.0 data transfer interface program. Through the comparison and analysis of several common interfaces of VI, finally, general data transfer module is developed based on USB2.0 bus controller EZ-USB FX2(CY7C68013), which is produced by CYPRESS, in slave FIFO mode. This paper presents in detail firmware, driver and application design, the hardware design of the module and timing logic control code of FPGA ,the data transfer between computer and vritual instrument system is realized.The test application shows that the interface complies with the USB2.0 protocol specification. It has good data transfer ability and can meet the requirements of data transimission between VI and computer. In addition, USB interface technology makes the connections of the computer and instrument easy, portable; VI technology make instrument have good expansibility and can realize more user self-defining function.The universal interface module developed for virtual instrument system combined these two excellences is flexible in use, powerful and so on. So it has good practical value and use prospect.