Problem with Superdrive, Parallels, OSX 10.10.2

I have a MacBook Pro Retina, Parallels 10, OSX 10.10.2. I am trying to install rt systems WCS 2730. I insert the disc into the drive, it whirs around and spits it out. I plugged the drive into the USB port and told Parallels to use it, but it still doesn't work. What am I doing wrong or what did I forget? Thanks.