Canon Speedlite 550EX Instructions Manual page 101

3. Setting the Master/Slave Channel
To prevent your master unit from firing another photographer's slave units,
four channels are provided to differentiate your slave units from unrelated
ones. The master unit and slave unit{s) in the same wireless flash system
must be set to the same channel No.
1
Press the master unit's <MOCE >
button and select M or MULTI .
The TTl
mode
cal'ltlOl
be
used with wifeless
llash ptlOlO gfllphy.
2
To sallhe master unit's channel No.,
press the < SEl / SET > bullon and
select ~ .
• Pressing ItII < SEL / SET ,. bu\!on en.nges
the
5eleclion
in the
following loop:
r
~
-+
Flash output ....
~
-+
. ~
J
- (Off)
~4 1-
_ _ _
.J
3
Press the
<
T
> or < - >
buttoo to set
the channel No. (1,2, 3, or 4).
101