OPC的异步读取数据的类的封装。将opc的初始化，异步读取，同步读取，写，停止等功能封装到类中。使用的时候自己创建一个vc6项目，然后把压缩文件中的文件放到项目根目录，include头文件后就可以用了。-OPC asynchronous read data class package. The opc initialization, asynchronous read, synchronous read, write, and stop functions encapsulated into classes. Was time to use vc6 to create a project, and then compress the files in the root directory into the project, include header file can be used after.