The 22 assignable buttons on the Keystation Pro 88 can each be assigned to toggle between two values. For example, you may want to use a button to toggle a function on and off (e.g. Mute, Solo, Record Enable) by sending out value 127 when you first press the button, followed by value 0 when you press the button a second time.

To set toggle values for the buttons:

1. Press an assignable button to select for editing.
2. Press the Function button labeled DATA MSB twice.
3. Type in 127 using the numerical keypad or the +/- keys.
4. Press the Function button labeled DATA LSB twice.
5. Type in 0 using the numerical keypad or the +/- keys. If you want the button to send the same value every time you press it*, enter the same value for both of the steps above.

* If you find you must press a button twice in order for it to toggle functions, the receiving device/software is ignoring the 0 value, set both for 127.