Canon SPEEDLITE EL-1 Advanced User's Manual page 137

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 that the same transmission channel and wireless radio ID are
set for all receiver units and the sender unit.
Set the receiver unit to add as A, B, or C respectively and place them in
position.
5.
Check the channel and ID.
If the transmission channels and wireless radio IDs of the sender unit
and receiver unit are different, set them to the same settings (
>.
137
> to select an item,
> to select <
).
>