how to control two fx3 usb respectively?

[fumac_3907466]

I will use two fx3 usb to communication with my devices. When I use the friendlyname to get the usb name. I only get one usb name, and I only control the newest opened usb. how to control two fx3 usb simultaneously and respectively?

CCyUSBDevice*   m_pCyUSBDevice;
for (UCHAR i = 0; i < m_pCyUSBDevice->DeviceCount(); ++i){
        bool isOpen = m_pCyUSBDevice->Open(i);
        if (isOpen){
            QString friendly_name = m_pCyUSBDevice->FriendlyName;
 }
}