A node indicates that a condition is in its on state. Heater on, lights on are two examples. 

 | Data byte | Description                                                        | 
 | :---------: | -----------                                                        | 
 | 0         | index. Often used as an index for channels within a module.        | 
 | 1         | Zone for which event applies to (0-255). 255 is all zones.         | 
 | 2         | Sub-zone for which event applies to (0-255). 255 is all sub-zones. | 
