MC75的USB驱动，安装后可以把MC75的USB添加为一个串口，进行AT命令收发。同时会生成一个modem，可以直接用它拨号。-The USB driver MC75, MC75 after installation of the USB can be added as a serial port for AT commands to send and receive. At the same time will generate a modem, can directly use it to