MIDI Over USB

You can use any USB based Generic MIDI device. I've played with it and a keys/fader/button board. You need to configure show control to receive the messages. New show control list type network. New event MIDI string. This should get you to the MIDI event editing menu in the CIA where you can configure how it will respond to the type of MIDI message it gets. You then also need to configure the Action you want the message to trigger/control. Make sure you take advantage of the diagnostics tab(99) to see what messages the device you have plugged in transmits. I hope this helps you out!

Hey Andrew, as I experienced it, there is a way simpler method to trigger the console via MIDI. Once the USB-to-Midi option is activated in the shell, it will automatically respond to incoming MSC messages (when also MSC receive is activated in the desk settings). Except that you don't need to configure anything. An MSC command with the format <device ID> <lighting general> <go> <cue number> (<cue list number>) will do. In the software I use to send MIDI commands, I can simply put these messages toghter via dropdown menus, no need to convert anything to Hex by hand :).
The only way to set faders (as Nandoaza would like it) is to use the MSC "set" command, but this only works step-based, not with fades. But to control channels (as submasters) outside of cues, this is a very handy feature, if sudden jumps to a certain level works for you.