Support for hardware control surfaces with faders (motorized or not), knobs and buttons can be configured in the Settings/MIDI Control box.
n-Track automatically detects and has pre-configured MIDI Control settings for the following devices:
Behringer BCF2000
Korg Nanokontrol2
Mackie Control
Tascam US428
Tascam US224
n-Track also works well with The Pok (a wireless foot controller that sends keyboard shortcuts)