This site is being deprecated.
Please see the official X‑Plane Support page for help.
X-Plane can handle and use multiple USB devices. You will need to ensure all of them are calibrated, and none of them have duplicate axis assignments or they won't work properly in the sim. If you are using device manager software, sometimes that causes problems with X-Plane.
Here is a tutorial video on setting up joysticks that might help you get started.
This site is no longer being actively maintained.