Hi Sarah,
You have to setup the hardware side of the GPI in "Edit | Hardware Setup" in the "GPI Boards"-tab. You can use either a regular GPI (pulse) through a serial port, Smart GPI (ASCII-based protocol) through the serial port, or a additional GPI-board (if fitted in the PC).
Now you can setup the sofware side of the GPI in "Edit | Keyboard / GPI Mapping". Here you can setup all sorts of wonderful things to happen when a GPI is triggered. I don't think you can actually fire different AnimControllers with a GPI (I have never tried that), but you can take a scene online/offline, so if you put each AnimController in a different scene and use GPI's to put these scenes online, it is possible you can trigger one AnimController after the other.
Good luck!
Kind regards,
Gerard
#XPression