Canon SPEEDLITE EL-1 Advanced User's Manual page 114

3.
Set a transmission channel.
Press the joystick up / down / left / right or turn <
< > or Ch.1 to 15, then push the joystick vertically.
4.
Select Item (2).
Select the ID item using the same operation as the transmission
channel setting, then push the joystick vertically.
114
> to select from