论文部分内容阅读
介绍了如何用自由口模式实现西门子公司的S7 200系列PLC与上位机的通讯,给出了一种简单的用户自定义协议,着重介绍了上,下位机之间具体通讯过程的实现,并给出了部分程序和流程图。该方案具有硬件简单、使用灵活的特点,对中小型控制系统实现通讯有一定的参考价值。
This paper introduces how to realize the communication between Siemens S7-200 PLC and PC by using Freeport mode. A simple user-defined protocol is given. The realization of specific communication process between upper and lower computer is introduced. Part of the program and flow chart. The program has the characteristics of simple hardware and flexible use, and has certain reference value for small and medium-sized control system to realize communication.