Design Of Grating Signal Acquisition & Processing Card Based On Programmable Logic Device

Some traditional digital devices have been replaced by Programmable Logic Devices (PLD) gradually for these advantages, such as small volume, high speed, light weight, high secrecy, short design cycle and low design risk, etc. Universal Serial Bus (USB) has the advantages of high transmission speed, Plug and Play, easy to extend, small occupied space and so on. With the development of modern industrial production and scientific research, the requirement of data acquisition has being increased daily. This dissertation develops a system based on PLD to process the data and on USB bus to acquire the data, combining the techniques of PLD, USB bus and the characteristics of traditional data acquisition.This dissertation analyzes the characteristics of the ISA bus based on data processing card, which was used on a 3-D coordinate measurement machine(CMM) developed by Tianjin University. This system improves data processing part and applies the PLD instead of the traditional 74 series chip, solves the problems of irregular working due to weld absence and missing, and overcomes the disadvantages of the traditional data acquisition card based on ISA bus. The data processing acquisition system designed in this dissertation has some features such as good real-time, high reliability, convenient to use and so on.Main works have been finished as follows:1. Determine the whole system by analyzing the function of previous data processing and acquisition system.2. After reading lots of datasheets of chips, the chips types are decided, and the whole system's circuit schematic is designed.3. Develop data processing program which can realize the function of quarter subdivisions, directional discrimination, reversible counting, latching signal processing and data selecting with Verilog hardware design language on QuartusII bench.4. In the environment of Keil uVision2, the USB firmware is programmed by using C51 language. In the environment of Visual Studio, CMM testing application program and USB device driver based on WDM are developed using Visual C++ language.5. In the environment of laboratory, by use of testing platform which is designed by our lab and simulates the grating signal of CMM, debug the system. Experiment indicates it can meet the requirements of this project.