DigiTech Midi Implementation Manual page 194

Midi receive channel (0 - 17)
0 Receive MIDI Disabled
1-16 Receive MIDI on Channel 1-16
17 Receive MIDI on All Channels
Midi transmit channel (0 - 16)
0 Transmit MIDI Disabled
1-16 Transmit MIDI on Channel 1-16
Active speaker simulator (0 - 13)
0 - 8 Factory Speaker Simulators 1-9
9 - 13 User Speaker Simulators U1-U5
5 User Speaker simulator definitions, U1 - U5
Each speaker definition is 6 bytes long. (5 * 6 = 30 bytes) The value of
each byte may be 0-24. (See the definition for the 63 Hz parameter for what
these values mean.)
Byte 1 160 Hz
Byte 2 400 Hz
Byte 3 1.0 kHz
Byte 4 2.5 kHz
Byte 5 6.3 kHz
Byte 6 16.0 kHz
Global link table of parameters to continuous controllers (P2CC)
All parameters in the GFX-1 are assigned a parameter number. This number is