【作者】 戴健雄；

【导师】 姜守达；

【作者基本信息】 哈尔滨工业大学 ， 仪器科学与技术， 2007， 硕士

【摘要】 VXI总线扫描A/D模块是VXIbus自动测试系统的通用模块之一。早期设计的扫描A/D模块不具备程控增益、自动校准和分通道信号调理等功能,而且扫描速度较低、精度较差、缓存较小、测量信号单一。为此需要重新设计一款通用型的扫描A/D模块,使之更好的满足实际测量需要。本模块采用FPGA技术,实现了VXI接口与SDRAM接口逻辑、AD采样控制以及程控放大设置,并解决了顺序扫描与任意次序扫描等问题,利用FPGA内置FIFO,提高了数据传输效率;采用了高速浮点型DSP作为主控CPU,接收VXI的各种命令与参数,分析命令、执行命令、协调模块各部分的工作以及对数据的处理;采用高速、大容量的SDRAM,满足了模块内数据存储的要求;采用栈接技术,通过不同功能调理板的组合可以实现对不同频率、不同量级信号的调理;采用高性能D/A芯片,实现了多量程增益调节;采用每通道单独配备继电器,通过选择模块内部自带的基准源输入并将其采样数据存储在模块中,实现了对测量数据的校正处理,提高了模块的精度。在软件设计中,编写了DSP固化程序,实现了与VXI通讯、控制采样以及数据存储;利用LabWindows/CVI作为软件开发平台编制了符合VPP规范的仪器驱动程序及汉化仪器软面板。实际测试及运行结果表明,本设计原理分析正确,研制的模块各项技术指标满足设计要求。更多还原

【Abstract】 VXIbus C size scanning A/D converter module is one of the important modules for integrating aviation automatic measurement systems. The Original Scanning-A/D-Converter Module doesn’t have functions of programmable gains, automatic calibrating, optional per-channel signal conditioning; and its scanning speed is low, measurement precision is poor. It is necessary to redesign this module, to meet the practual requirement.The module uses FPGA technology to control the VXI interface and the A/D converter and the PGA.It deals with the problem of the order scanning and the random scanning. Interruption associate with large capacity FIFO is used to improve the capability of channels parallel communication. High speed and big capacity DRAM is used to solve the problem of huge throughput capacity. Use high speed, large addressing space and float-point DSP to deal with the problem of too many channels and data architecture complex and high data transfers speed. With the technique of hardware paste, multiple children boards can be combined to provide proper signal conditioning for a wide variety of input signals. A high performance D/A converter is adopted to accomplish the programmable gain adjusting. The module also provides on-board reference sources that can be selected as input by the relay in every channel and stored in the module to compensate for system offsets, improving the measurement precision; n the design of software, program the DSP software to realize different buses work at one time. The drivers and panels, which accord with the VXI plug&play specification are developed based on the Labwindows/CVI, and complete the data transmission between the module and the computer.As can be seen from actual test, the VXI-aviation serial communication module is designed in reason and satisfies all the performance.更多还原