这个是基于labwindows的串口编程源代码。包括串口打开，发送数据，接收数据等功能。在此基础上，实现了一个简单的通信协议。-This is labwindows serial programming source code. Including serial open, send data, receive data, and other functions. On this basis, a simple communication protocol.

用VB编程与三菱A系列PLC通信的源码,需要编写串口通讯工程的可以参考,(VB programming with Mitsubishi A series of PLC communication source code, the need to write serial communication engineering can refer to,)