【作者】 张波；

【导师】 周纯杰；

【作者基本信息】 华中科技大学 ， 控制理论与控制工程， 2005， 硕士

【摘要】 嵌入式系统是一种以应用为中心,以计算机技术为基础,软硬件可裁剪,适应对功能、可靠性、成本、体积、功耗严格要求的专用计算机系统。可编程控制器作为目前工业自动化的重要基础设备,被称为“工业自动化三大支柱性产业之一”,在各工业生产领域发挥着愈来愈大的作用。本文结合开发项目“基于C8051F040 单片机的嵌入式系统开发”,在深入研究嵌入式系统技术的基础上,提出了小型PLC 设计的系统方案。硬件结构以高性能的8 位嵌入式处理器C8051F040 为核心,充分利用其丰富的片上资源,扩展系统的输入输出功能。软件以开发的PLC 内核为核心,开发系统所需要的应用,将嵌入式PLC内核扩展为完整、实用的PLC 系统。本文深入研究以C8051F040 单片机为核心的PLC 硬件核心电路,包括掉电保护的外部RAM、硬件看门狗和对外部扩展的接口电路。同时研究了PLC 核心的内核软件,包括内核软件的基本功能、内核软件的结构和实现,以及内核对任务的管理和调度。接着研究和分析PLC 的电源,结合最新的开关电源技术,设计出适合小型PLC所需要的电源。以美国功率集成公司(Power Integrations Inc.)的TOPSwitch-II 系列的单片开关电源芯片TOP224Y 为核心,提出开关电源的设计方法和步骤,以及如何选用外围元器件,并且测试了开关电源的性能。研究PLC 主要硬件部分,包括输入输出和通信部分,设计出符合小型PLC 的硬件电路。应用PLC 内核程序,设计出具体的PLC 应用软件。最后结合具体的PLC 应用系统,对该PLC 做整机测试,以及进行PLC 网络扩展试验,对其性能进行评估。更多还原

【Abstract】 Embedded systems are special computer system. They are based on computer technology and take the application as the first important thing, their software and hardware can be cut out, and they also fit for application systems which have strict request with function, reliability, cost, power waste and bulk. As the very important basic equipment, Programmable Logic Controller (PLC) is called one of the three major pillars in Automation Industry. In the thesis, under the developed project “Embedded systems development based on C8051F040 MCU”, and on the base of studying embedded systems technology, the paper presents design plan for the small PLC. The hardware is based on the high efficient 8 bit embedded microprocessor C8051F040, its input and output function is extended with its plenty of source on chip. The embedded PLC core programme is taken as the center, and the needed application is developed, and is extended to a full and applied PLC system. In the thesis, the PLC core hardware circuit which is based on the microcontroller C8051F040 is deeply studied, including external RAM for power dropping, hardware watchdog circuit and the interface circuit for extent. At the same time, The PLC core software is studied, including its basic function, its structure and realization, its task administration and schedule. Then the power supply of PLC is studied and analyzed, and the power suitable for the small PLC is designed combined the up-to-date SMPS (Switching Mode Power Supply) technology. Base on the singal chip SMPS TOP224Y in the TOPSwitch-II serial of American company Power Integrations Inc., the design method and step of SMPS, and how to select components is presented, basides the performance of SMPS tested. The PLC hardware including the input/output and the communication is studied, and the hardware circuit for the small PLC is designed. The PLC software under the PLC core is designed. At last the PLC system combining an application of PLC is tested, and its performance is evaluated by PLC network extent.更多还原