Last week I helped Bas verifying his MIDI layout of the Reloop Digital Jockey 2 interface and controller edition. I used a program for Windows called MIDI-OX, a diagnostic tool for the MIDI protocol, to do this. In order to lookup the MIDI information sent by your MIDI controller turn on your device, start MIDI-OX and go to Options > MIDI Devices.
In this window select your MIDI Controller inputs in the MIDI Inputs list. Press Ok and go to View > Input Monitor to view the MIDI input of your controller.
For all buttons and keys on your controller the MIDI note is listed in the NOTE column. Unfortunately when using the knobs and sliders on my Digital Jockey 2 no information was shown about the channel used. Please post a comment if you know how to extract this information or if there are better tools to view MIDI data.