Pigtronix Echolution-2 Deluxe - Manual (Page 21)

Buttons can be controlled in two ways, to allow
automated patches and also real time manual control.
Button Patch Control
Set the button value to “1” for a SHORT PRESS.
Set the button value to “2” for a LONG PRESS
This allows commands to be sent quickly to the E2
without worrying about timing, which makes
automated control easy.
Manual Button Control via MIDI
This is convenient for manual control of the E2
through something like a foot controller, but would be
very inconvenient for automated control.
Set the button to “127” to indicate that the button
should change state from “unpressed” to “pressed”.
Set the button to “0” to indicate that the button
should change state from “pressed” to “unpressed”.
The time between the above two messages decides if
the press is a long or short press. This means that the
controlling button on the MIDI controller behaves
exactly as the equivalent button would on the E2 front
panel.
Manual and Patch controls can be mixed as necessary.