A node indicates that a warning condition occurred. 

 | Data byte | Description | 
 | :---------: | ----------- | 
 | 0         | Reserved level. | 
 | 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. | 
