Should have updated you Jim, POWER-LOSS statement was added a while back. You just need to update your firmware and can test it out yourself.
To let the other controllers in the system know about a particular device going offline you would do a small program on each controller to flip a variable, then toggle it off once you’re done processing the event.
Each panel in the system has a program like so, say we’re on panel2 here. The first line turns on a variable when the power comes back on and the second line turns it off once the ‘master’ has acted on the event.
10 IF POWER-LOSS THEN START 2VAR1
20 IF TIME-ON( 1OUT1 ) > 0:0:10 THEN STOP 2VAR1
Let’s use Panel1 to act as the ‘master’ which turns on an LED or takes some other action.
10 IF 2VAR1 THEN START 1OUT1