This is typical for changing TV channels or for changing AV amp input source etc. 

 | Data byte | Description                                                                                                                                                                                                                                                                                                                                               | 
 | :---------: | -----------                                                                                                                                                                                                                                                                                                                                               | 
 | 0         | A value between 0 and 127 indicates the channel number. A value between 128 to 157 is change down by the specified number of channels. A value between 160 to 191 is change up by the specified number of channels. A value of 255 means that this is an extended change channel event and that the channel number is sent in byte 3 and after if needed. | 
 | 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.                                                                                                                                                                                                                                                                                        | 
