摘要：論述了利用PLC 的串口通信技術，實現上位機對溴化鋰制冷機組的遠程實時監控。文中還對OMRON公司的C200H型PLC的通信協議進行了分析，并介紹了基于VC++的上位機通信程序設計思想。
關鍵字：PLC，上位機，溴化鋰制冷機組，串口通信

Abstract： This paper presents the realization of a successful remote supervisory on a BrLi chiller, by means of RS-232 between PLC and Computer. The communication agreement of the style C200H of OMRON was analysed, and the method of VC++ program design is also introduced.
Keywords：PLC, supervisory computer, BrLi chiller, serial communication