【作者】 程炜；

【导师】 庞彦斌；

【作者基本信息】 北京化工大学 ， 检测技术与自动化装置， 2001， 硕士

【摘要】 基金会现场总线FF集中了开放型的通讯能力和对生产过程的监控功能，是最适用于生产过程自动化领域的现场总线。本课题的目的是通过开发总线型气动阀门定位器，对现场总线设备的开发方式、方法进行研究。 在对不同的现场设备开发思路进行分析、对比的基础上，提出了总线仪表可采取直接开发与OEM方式开发的思想。本课题结合现有条件，选择了OEM的开发方式，并提出了双CPU结构的总体设计方案。开发工作分为两部分，即设备卡软硬件开发和圆卡应用软件开发。根据对阀门定位器演变历程、原理，及同类产品的结构和功能的分析，设计了以单片机为核心、具有I／O信号处理和人机接口、控制运算等功能的设备卡硬件和软件，并力求功能强、结构简洁紧凑、功耗低。圆卡开发，主要包括与总线和设备卡通讯的软件及设备功能块软件，该部分工作利用NI公司开发工具提供的圆卡、通讯栈软件及功能块壳完成。设备卡与圆卡之间的通讯采用串行方式实现，而圆卡负责实现总线通讯，从而使其构成的智能阀门定位器具有了总线现场仪表功能。开发过程中还巧妙地利用了HART协议等技术。 实验测试表明圆卡与模拟设备卡之间能够实现信息交换，仪表能够运行于总线之上，完成与系统的互操作。证明了整体设计方案和所采用的开发方法是可行的。本课题的研究对如何进行总线设备的开发进行了开创性的探索，提供了一些可借鉴的思路；对开发工具的使用，特别是功能块壳的应用积累了经验；其结果对FF总线智能阀门定位器的研制，以及其它FF总线设备的开发具有一定的指导意义。更多还原

【Abstract】 Integrating the open communication and process control abilities, the FOUNDATION Fieldbus (FF) is the best fieldbus for process automation area. The project is intended to develop the pneumatic valve positioner based on FF, on base of which to study the developing scheme and method of the Fieldbus device.The scheme of developing fildbus device by direct method and OEM method is first presented, depending on the analysis and compare of different developing methods. In view of the available situation, the later one is selected and the overall design is made comprised of two CPU. The work is accordingly divided into two parts: software & hardware development of Device Card and software development of Round Card. The MCS51 CPU is the kernel of Device Card, performing the functions like I/O signal processing, HMI interface, control algorithm. It tries to achieve multi-function, simple in structure and low in power consumption. Round Card software includes the communication software with network and with Device Card, and Function Block algorithm. This is realized using the Round Card, commnication stack software and Function Block SHELL in the development kits of NI Corp. By means of the serial communication between the two cards and communication to the fildbus by Round Card, the valve positioner is equipped with the FF field device function. Further, HART protocol is made full use of in the project.The experiment indicates that the two cards can communicate with each other, the whole device can run on the fieldbus and interact with the system. This approves the feasibility of the overall design scheme andmethod. The original study of how to develop a fieldbus device provides some advisable clues for future study; gains much experience in using the development kits, specially in using the Function Block Shell; the result is of some instructing value for developping intelligent valve positioner based on FF, and other fieldbus devices as well.更多还原