Dunno for sure what exactly that device is capable of, but typically a MIDI port on an effects device allows you to send information, change patches or parameters via MIDI. Things people typically use this sort of thing for include:
Using a MIDI footswitch to change or bypass the effect that is being used during a performance. Some of these footswitches have lots of buttons and expression pedals and allow a LOT of control over the effects. This can be pretty handy if you use a lot of effects when gigging.
Allowing a MIDI sequencer to change or bypass effects during a sequence automatically. If you had a sequencer program (cakewalk, cubase, etc.) running a synthesizer and wanted the first half of the song to be reverbed and the second half to be flanged, you could program the sequencer to change the effect for you.
Saving or retrieving patch information via a bulk dump...this way, if you have a bunch of presets you've worked hard to tweak to your liking, you can back them up. Then if they get messed up somehow you can reload them.
Some processors also have computer software that makes it a lot easier to adjust the more intricate parameters of the device via the computer so you don't have to sit there squinting into a little LCD trying to figure out what button does what. These programs are also useful for backing up presets. I don't know if yours can do this or not.
Hope this helps,
OB
