If you mean how to sync them, then this is how:
1. Go to edit > preferences. In preferences, select the SMPTE/MTC tab. Set your MIDI out for sync (or input if you want the MPC as master).
2. Go to multi-track view (you can only sync in multi-track btw). Here, right-click on the time-line and select your frame rate (fps) in 'display time format' (say, SMPTE 25 - but it doesn't matter as long as it's the same as in the MPC).
3. In the MPC, do the same in the MIDI/other screen. It is probably best to slave the MPC while recording, so select the input and set it to MTC (MIDI time code) with the correct frame rate.
4. Press play on the MPC, and it should say "Waiting for MTC input" or something like that. Press play on AA3 and the MPC should now follow if your connections are all go.
You should leave an empty bar at the beginning of whatever you are recording, because MTC takes a little time to sync up - this way you ensure your MPC has time to catch up.
That should be it!
And welcome to the forums.
