There are two types of triggers you can use in Scenes set up with Atom: schedule, which allows you to set the scene to automatically go off at a certain time, and manual, whereby you'd manually activate the scene when needed.
Device-based triggers (i.e. when a certain device does something or changes its state) isn't a feature that's supported just now with Atom—although it will be implemented with a future update. It does work with our Vera controllers.
Please go here for more details on Ezlo Atom scenes.