Canon SPEEDLITE 270EX II Mode D'emploi page 18

[External flash C.Fn setting]
C.Fn-01: Auto power off (Enabled*/Disabled)
C.Fn-06: Quick flash w/continuous shot (Disabled*/Enabled)
C.Fn-10: Slave auto power off timer (60 minutes*/10 minutes)
During normal auto power off (C.Fn-01), the power turns off if no operations are
made within 90 seconds, but in slave mode, the power turns off if no operations
are made within 60 or 10 minutes.
C.Fn-11: Slave auto power off cancel (Within 8 hours*/Within 1 hour)
When the master unit has a function to cancel the auto power off on the slave
unit, the master unit can cancel the auto power off on the slave unit within eight
hours or one hour after the slave unit enters the auto power off mode.
16