摘要
目前,分散控制系统广泛应用于工业化生产中。针对分散控制系统的实时性、稳定性、可靠性的要求,设计基于QNX(Quick UNIX)与Cortex-A8(超标量微处理器内核)的分散控制系统。该分散控制系统采用控制器局域网(CAN)通信方式,实现现场控制站与现场采集模块之间的数据传送。现场控制站要求主控制器和支持CAN协议的输入/输出(I/O)模块之间实时地进行数据交换,包括现场控制站向I/O模块发送各种指令和数据以及接收I/O模块下发工程师站和操作员站的操作指令。由于I/O模块包含各种模拟量和数字量输入输出卡件,因此采用CAN网络通信具有较高的实时性。结合相关资料介绍CAN控制器的硬件结构及其功能。在QNX6.5嵌入式操作系统开发环境下,基于Cortex-A8处理器,编写CAN网络驱动程序,并进行测试,测试表明采用CAN网络通信能够很好地满足电厂对实时性、稳定性的要求。
At present,the distributed control system is widely used in industrial production. According to the real-time,stability and reliability requirement of distributed control system,a distributed control system based on QNX and Cortex-A8 was designed. This system adopted the CAN( Controller Area Network) communication way,realized data transfer between field control station and acquisition module. Field control station demanded that the main controller exchanged data in realtime with the I / O module,including sending instructions and data supporting CAN agreement,and receiving the I / O module instructions issued by the engineer station and operator station. Because the I / O module contains a variety of analog and digital input and output cards,so adopting CAN communication network has high real-time performance. Combined with the related information,the hardware structure of CAN and function of the controller were introduced. In QNX6. 5 embedded operating system development environment,based on the Cortex-A8,the CAN network driver was written and tested. The test results show that the CAN network communication can meet the real-time and stability requirements of a very good power plant.
引文
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