Triggers are based upon external actions.  Triggers can be declared for a number of external events including the sending and receiving of Insteon, UPB, X10, and Infrared signals, by plugins, by Windows messages, incoming Socket connections, global variable changes, etc.  Anytime you want to perform an action based upon some other action occurring, you’ll probably want to define a trigger.  Triggers also include a Boolean formula which is checked whenever a trigger fires.  If the formula is true then the trigger's action is performed.  Actions can be either a Macro, Send Keys, Raw formula, or a Device Control string.  Triggers are declared from within the Triggers section of the PowerHome Explorer.