https://s3.amazonaws.com/com.eventide.downloads/Product+Manuals/H9-UserGuide.pdf
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Using the Right Footswitch to Tap Tempo or Parameter Values
To turn Tap Mode ON/OFF, press and hold the right footswitch for 2 seconds. A blinking Tap LED indicates that both Tap Mode and Tempo are ON. Under these conditions, tapping the Right Footswitch will adjust the Tempo and the display will indicate the Tempo in BPM. A solidly lit Tap LED indicates that Tap Mode is ON but Tempo is OFF. Under these conditions, tapping the Right Footswitch will set the value of the given algorithm's "tappable" parameters. The display will indicate the value for those parameters (usually in mSec or Hz).
