What kind of bus does the the ultrasonic sensor work by?
Using the sbRIO, there are options of communication via protocols such as wireless. If the sensor uses TCP/IP or UDP to transmit and receive data, then it should be possible to write a driver in LabVIEW RT to talk to the sensor. How complex and involved that driver may need to be will depend on the sensor.
As the sbRIO runs on real-time, we also would need to check compatability between the sbRIO and any sensor that you're wishing to plug into it as drivers may have only been developed for a windows OS. If it is compatible, then we can explore options such as communicating to it via VISA commands.