在工业控制领域中，PLC作为一种稳定可靠的控制器得到广泛的应用。但它也有自身的一些缺点，即数据的计算机处理能力较弱，不能给用户提供良好的界面等。而计算机恰好能弥补PLC的不足，他不但有很强的数据处理和管理能力，而且能给用户提供非常美观而又易于操作的界面。将PLC与计算机结合，可是系统达到既能及时采集、存储数据，又可处理和使用好数据，两者结合的关键是PLC与计算机之间的通信。由于微软的MScomm通信控件具有丰富的与串行通信密切相关的属性及事件，提供了对串口的各种操作，并且在串口编程时非常方便，而且在DELPHI中容易得到使用。-In the field of industrial control, PLC as a reliable controller is applied widely. But it also has some shortcomings, namely, its data processing ability of computer is weak, cannot offer users good interface, etc. While the computer just can make up the deficiency of PLC, he not only has a strong data processing and management ability, and can offer customers very beautiful and easy-to-use interface. PLC and computer will achieve system, but can timely data collection, storage and handling and use good data, the key is the combination of PLC and computer communication between. Because of the Microsoft MScomm communication control with rich and serial communication is closely related to the properties and events, provided for all kinds of operation, and the serial port in serial when programming is very convenient, but also in DELPHI easy in use.