There should be some DP switches on the unit, are these set-up correctly? If they are not the driver and the hardware will not be able to speak to each other.
Can you go into Device Manager on your computer (Click Start and Search 'Device Manager') right click on the device and go to properties, I assume the driver version is out of date and may need to be updated.
In the technical reference manual, it says that the USB model needs to have the USB device driver installed, as you have done, but it is important you install the driver before plugging it in, Windows could be using plug and play and of installed the wrong one.
Please remove the driver from device manager and reinstall the latest
Is this now resolved for you?