Canon SPEEDLITE EL-1 Advanced User's Manual page 185

2.
Select an item in (1).
Push the joystick up / down / left / right or turn <
and push the joystick vertically.
3.
Set to <
Press the joystick to the left or right, turn <
to select, then push the joystick vertically.
4.
Configuring after setting the firing groups to A, B, and C.
Check whether all the receiver units are set to the same transmission
channel as the sender unit.
Set the receiver unit to add as A, B, or C respectively and place them in
position.
5.
Check the transmission channel.
If the channels of the sender unit and receiver unit are different, set
them to the same number (
>.
).
185
> to select an item,
> to select < >