用DELPHIE来实现下位机和上位机的串口通信！相信会对需要的人有很大的帮助！-DELPHIE used to achieve lower computer and the PC serial communications! I believe this would have need of a great help!

西门子200PLC与上位机通信 delphi开发经典源码-PC 200PLC with Siemens Communications to develop the classic source delphi

PLC串口调试程序,串行通信编程的方法，对采用了RS-232接口的仪器进行串行通信的计算机测控软件开发，以及实现仪器功能和指标的验收-Microsoft Comm Control 6.0中）-vb serial communications debugging method existing electronic weighing a Taiwan, the use of serial communication with the computer. Preparation of VB to v

海为PLC上位机与PLC通讯的组件，支持VB，VC，Delphi等开发工具(Haiwei PLC communications test program)