Track Flick

The Track Flick alert is designed to fire when a track circuit transitions from occupied to unoccupied under a given time. The amount of time provided in the alert should be any value lower than the fastest valid occupation time for the track circuit.

The alert should correctly capture the following conditions;

• Track circuit flicking during passage of a train
• Track circuit flicking with no passage of train

Real Example

(AH track circuit transitioned from Dn to Up in 460 milliseconds)

	AH TPR	Up	13:29:25.380	Note: Replay confirms there is no occupation of TRs in either direction Derived Assumption: No train was in section
	AH TPR	Dn	13:29:27.420
	AH TPR	Up	13:29:27.880	Note: Replay confirms there is no occupation of TRs in either direction Derived Assumption: No train was in section

Inputs

Logic

When the TPR transition time from occupied (Dn) to unoccupied (Up) is less than the minimum occupation time, the alert will fire.