In this paper, introduces the Communication protocols and instructions of MITSUBISH FX series PLC with programming cable SC-09, and uses MSComm control box of VB6.0 to design the serial port communication program.

• 文介绍了三菱FX系列PLC在SC-09下的通信协议与指令；并利用VB6.；0的MSComm控件进行串行通信程序的设计。