I want to make sure to clarify this point. USB is a serial
communication method talking to many devices which has an inherent
large amount of jitter and communication overhead. Doing USB communication
adds to the jitter of the system which is a bad thing for RT systems. This is the
reason we recommend using TCP/IP for your RT communication.
As to your question of why we have the USB ports on the controller, they are used for the Windows variants of our PXI embedded controllers. You'll notice that most of our PXI controller offerings have both a Windows XP and LabVIEW RT variant.