The Null button activates and de-activates Null Mode. By default, Null Mode is always active and the Null button will illuminate when this is the case. In Null Mode, the position of Axiom Faders is stored as part of a user Patch. This is known as their Null value. If a fader is at a different position or value when the patch is recalled the LCD will display “MUTE” and a value representing how far off they are from the Null value. The fader will not transmit MIDI data until the Null Value has been reached. This prevents corresponding parameters in the software from jumping to a different value as the Axiom control is adjusted. The Axiom Fader will be “un-muted” as soon as the position matches the value stored in the user patch.

For example, in qualified versions of Pro Tools, Axiom Preset 9 can be used to control the virtual instrument called Velvet. When an instrument parameter is edited using an Axiom Fader, its new position is retained as the Null value when a new preset is selected. If the same fader is used to edit the new preset, it is likely to be in a different position when Preset 9 is recalled. Because Null Mode is active by default, the fader will not transmit MIDI data to Velvet until it has been adjusted to its Null Value. This prevents it from transmitting a MIDI CC value that will cause an unwanted parameter change in Velvet.