介紹了以AT90mega8515 嵌入式單片機構成的單總線溫濕度采集系統在PLC 控制網絡中的應用，以及通過OMRON 公司PLC 構建的Host Link 控制系統，實現對下層PLC 的監控。系統的高性能上位機同時為嵌入式系統提供了應用接口。運用C++Builder6.0 編制可視化監控軟件并通過多線程技術提高系統響應速度。
關鍵詞 PLC 嵌入式系統 RS422A 1-wire 多線程

The application of embedded system in traditional PLC control system CHENG Kang, CHEN Jia-pin, LI Zhen-bo (Key Laboratory for Thin Film and Microfabrication Technology of Ministry of Education, Shanghai Jiaotong University, Shanghai 200030, P.R, China) Abstract It is introduced how the 1-wire data collection system based on embedded MCU(AT90mega8515) to be used in the traditional PLC control system. The Host Link control net constructed with OMRON PLC complete monitoring the substrate PLC. In the mean time, the high-powered upper PC support the application of the embedded system. The visible monitoring software is organized with C++Builder6.0, and the response speed is improved by the technique of multithread.
Key words : PLC; embedded system; RS422A; 1-wire; multithread