Tempo and Metronome in the owner's manuals

Tap Tempo Mode

The Global menu provides a Tap Tempo mode option. “Average” averages up to the last ten taps. “Last Two” uses only the most recent two taps to determine the tempo.

When tapping the tempo, the Tempo menu appears. You can specify in the Global menu how long it should stay on-screen.

Cliff: "The tempo LED is handled by a low-priority thread so it isn't rock solid and the higher the CPU usage the less solid it will be. The metronome, however, is perfectly accurate." source

Fractal Audio devices can output a metronome signal via the Tempo menu. The metronome plays through Output 1 only. You can start the metronome using an IA switch or through the Tempo menu.

If the parameter Auto Delay in the Tempo menu is “ON,” any delay blocks that are bypassed will become active whenever a tempo is tapped in. This allows you to set the tempo and un-bypass your delay block(s) from a single footswitch.

In some situations it may be desirable to send tempo information to the Axe-FX when changing presets. This reduces the need to maintain many similar presets for songs with different tempos. This Thread provides a list of hexadecimal codes that control Axe-FX tempo. These can be inserted into the MFC-101's Preset Custom MIDI Message field in order to set a desired tempo when a preset is loaded. They can also be used Sysex editors, or with any MIDI controller that has the capacity to send custom hexadecimal messages.