单片机作为一种方便实用的微处理器,在各类电子产品设计中都得到广泛的使用;而PLC作为工控系统也广泛应用在工业控制的各个领域。但是,PLC由于自身所带模块较少,应用成本比较高。为了增加PLC应用的灵活性和降低运用成本,使PLC能够更加广泛的应用在工业控制和自动化的各个领域,提出了在单片机与PLC之间进行串口通信。本文以松下电工FP0系列PLC和AT89C51为例,研究了单片机和PLC如何进行串口通信。 Microcontroller as a convenient and practical microprocessor, in the design of various types of electronic products are widely used; and PLC as an industrial control system is also widely used in various fields of industrial control. However, PLC because of its own module with fewer applications cost is relatively high. In order to increase the flexibility of PLC applications and reduce the cost of operation, PLC can be more widely used in various fields of industrial control and automation, proposed serial communication between the microcontroller and PLC. In this paper, Matsushita Electric FP0 series PLC and AT89C51, for example, studied how the microcontroller and PLC serial communication.