In the AV-forum Ritchief gave the answer:
'You are correct a trigger can be assigned per source, ie you only want your rear and ctre speaker amp to be turned off/on when watching a BR/DVD and not whilst listening to the CD.
How to do it:
Select the source, now using the menu buttons to go:
Say, DVD > now in the menu screen to go SOURCE SET UP > TRIGGERS, now select on / off.
This will now turn on the connect piece of kit every time you select this source (assuming of course you have connected the back of 12v triggers to the associated devices).
You can also set the delay timing of the source equipment being turned off/on by going to MENU SETUP > MISCELLANEOUS > TRIG DELAY, and selecting the timings from the menu.
For example, I have mine setup so that trigger one is activated when I select DVD & SAT so that the surround sound channel amp is turned off/on with a delay of 5 seconds.'
See also release notes for Fw 2012.11.