Encoder Wheel; Enter Button; Scene Memory Buttons - Yamaha O2R Owner's Manual

The CURSOR buttons are also used to position the cursor in a name
when naming automation mixes, scene memories, equalizer programs,
effects programs, dynamics programs, and channel library programs.
When a display left or right icon appears at the left or right side of the
display, indicating that another display page is available, the CURSOR
buttons are used to select that display

Encoder Wheel

The encoder wheel is used to adjust the parameter selected using the
CURSOR buttons. Its detented action gives it a positive feel, allowing
quick and accurate parameter adjustments. Turning it clockwise
increases the selected parameter value. Turning it counterclockwise
decreases the selected parameter value. The faster you turn it, the faster
the parameter value changes.
The encoder wheel is also used to scroll through the automation
programs, mix scenes, effects programs, EQ programs, and dynamics
processor programs. When naming automation programs, mix scenes,
user effects programs, user EQ programs, and user dynamics programs,
the encoder wheel is used to scroll through the available characters.

ENTER Button

The [ENTER] button is used to confirm settings made using the encoder
wheel and to toggle two-option parameters such as EQ ON/OFF.

SCENE MEMORY Buttons

These buttons allow you to select, store and recall scene memories. The
current scene memory is indicated on the SCENE MEMORY LED.
User Interface 21
Digital Recording Console 02R User's Guide