Vxi Dsp-based High-speed High-precision Data Acquisition Technology

The VXI-bus based test platform is the leading technology in the field of instrument testing,it can easily make up the automatic testing system. VXI-bus's modulation,flexibility,plug & play and high data throughput make it widely used in the industrial society. This paper presents a high speed and high precision data sampling system based on the VXI-bus.Due to the high data throughput and the need of real-time digital signal processing in high-speed data sampling system,we proposed to use DSP to do real-time signal processing to minimize the rate of data transferring and reduce memory size. The high performance of DSP can quickly respond to high speed I/O. Now,DSP based high-speed data sampling system has become a basic module in VXI automatic testing system.In this paper,we proposed a VXI Versatile Plug-in (WP) instrument platform. The VXI Versatile Plug-in (VVP) platform is a register-based,C-size,32-bit and single slot instrument. A complete VVP instrument consists of one enhanced main board and four plug-in boards,which is suitable for constructing basic instruments. The main board uses a 32-bits floating point DSP to do the real-time control and digital signal processing.Based on the VVP platform,our team has developed a high speed and high precision data sampling module. As a plug-in board in VVP,it uses a 20Mhz 16-bit A/D converter to sample analog signals. It contains two A/D channels,every channel has a 4KX 16bit buffer. It has three flexible trigger modes:inner trig,outer trig and software trig. VVP platform can support up to 4 plug-in boards (8 channel A/D) to work together.VXI instrument doesn't have the traditional instrument panel,we can control the VXI instrument by the computer. Computer soft panel realizes the interaction between users and instrument. The soft panel interacts with the users by a graphic interface.which helps the users to be familiar with and operate the instrument in a short period of time. In this sampling system,we provide a powerful soft panel that can easily control the VXI instrument.Finally,some testing data and conclusion is given.