Development Of LXI Counter

This thesis gives emphasis on the design of LXI counter module. LXI, which integrated the ease use of GPIB, high performance and small size of VXI and the flexibility as well as high throughput capacity of Ethernet into the instrument, is now regarded as the new generation of modularized automatic test instrument platform based on Ethernet technology. It has been developing rapidly because of its tremendous potential in distributed measurement and applications of hybrid instruments. The counter module is one of the most important and frequently used modules in automatic test system. It can be widely used in many fields, such as frequency measurement, time interval measurement, period measurement, pulse serial measurement etc.On the basis of the analyses on the development status of universal counter and the requirements of the users, the whole scheme of LXI is determined in this thesis. The LXI counter module introduces the basic truss of ARM + FPGA .ARM is used as the main controller and FPGA is used to realize the function. ARM runs the Linux operating system, as it has a strong network of support function and support all standard Internet standards, we can use the ARM hardware platform for the realization of LAN interface.The methods of adopting FPGA to realize the function of counter as well as adopting Verilog HDL (Hardware Description Language) to design every function modules make the whole design more compact and stable and make the alteration of the circuit function merely need to alter the software according to the practical task requires, and needn't alter the hardware connection of the circuit. The method of dither-removing controlled by program and isolation technique are adopted in channel design to enhance the capability of noise-resistant are employed to accomplish high-speed transmission for data, which improve the noise restraint and electric isolation.The Web-based interface control method which follows LXI software architecture has been realized in the software design. And the software panel and IVI-COM driver are developed in the software development platform of Visual C++2005. The LXI counter has been debugged and applied, the application indicates that the scheme is reasonable and the LXI counter module meets the requirements of the design.