The passing data transmitted by the Active Transponder also includes 2 fields which help flag potential issues with the transponder or your timing setup. 

Warning Flag

The warning flag is a single bit which is either 1 or 0, where 1 represents that a warning flag has been triggered on the transponder. The warning flag will always only be sent with the next passing and will then be reset, it will only be sent again if the same or another warning is triggered. Thus warning flags are always to be considered from the LAST passing recorded. A passing in this regard is considered a passing from Ubidium, an Active Extension or a Loop Box.

V3

The warning flag is used in combination with the Wake Up Counter (WUC) to indicate the reason for the warning, it may be difficult to ascertain the reason for a warning flag with the first passing but if the warning flag is triggered during the event then this is more reason for concern. 

The following combinations are possible:

Warning Flag Set / WUC + 1 (regular passing): Either the transponder was woken up from Deep Sleep mode or the transponder detected high noise and entered Noise Suppression Mode. During an event a transponder should not enter Deep Sleep and so it can be assumed that this is a high noise warning. 

Warning Flag Set / WUC + 2: High RX Error count - the transponder could not decode the loop data correctly. 

Warning Flag Set / WUC + 5: Very high noise detected - the transponder entered Noise Suppression Mode but was still activated by high noise. 

Warning Flag Set / WUC + 10: Transponder rebooted - please contact RACE RESULT. 

V2

The warning flag is only used to indicate when a transponder was woken from Deep Sleep mode on V2 transponders.