Check out this great in-depth review of the BirdDog PTZ Controller, below.
I opened the box, connected it with my network switch via a cat 6 cable ONLY, and BAM. She fired up and allowed me to access all NDI cameras on my network. It took the power through the network aswell.
This is an excellent solution for limited crew productions as well as allowing camera operators to do their thing well out of the way of the staging area.
Example: a school production in which the person doing the live switching can communicate vocall nvia the intercom channel to the camera operator at a different workstation. They see the production screen at their end via NDI.