Canon MR-14EX II Instruction Manual page 58

q: Wireless Multiple Flash Shooting with Manual Flash Output
If you shoot or fire the test flash with receiver A and B positioned when
C.Fn-15-0 is set, receiver A and B may fire. Turn off the receiver A and B.
When <j> is set with C.Fn-15 set to 1, you can set any of A, B, or C
as the firing group for the receiver units. Each group will fire according to the
set flash output.
56
Set the flash output.
4
Press function button 3 <1> or

<8>.
Turn <9> to set the flash output,

then press <8>.
Repeat steps 3 and 4 to set the flash

output for all groups.
Take the picture.
5
Each group fires at the set flash

output.