The Mixer 7s' faders and other controls respond to controller messages.
Here's a list of controllers and what they do:

Volume, Pan,

Channel 1: 16 24,
Channel 2: 17 25
Channel 3: 18 26
Channel 4: 19 27
Channel 5: 20 28
Channel 6: 21 29
Channel 7: 22 30

FX Send 1, FX Send 2,
R L R L
Channel 1: (70, 71) (70, 71)
Channel 2: (72, 73) (72, 73)
Channel 3: (74, 75) (74, 75)
Channel 4: (76, 77) (76, 77)
Channel 5: (78, 79) (78, 79)
Channel 6: (80, 81) (80, 81)
Channel 7: (82, 83) (82, 83)

Bass EQ, Treble EQ
Channel 1: 32 40
Channel 2: 33 41
Channel 3: 34 42
Channel 4: 35 43
Channel 5: 36 44
Channel 6: 37 45
Channel 7: 38 46



Volume, Pan, Bass EQ, Treble EQ
Main out 23 31 39 47


Smoothing enable: 53 (on, off controller)

Smoothing ammount: 48

Gate enable: 51 (on, off)

Gate attack: 50

Gate release: 49