Have done it Keith. Not that complicated after you have done it once. What current sensor are you using? - Are you getting real-time telemetry data back to your transmitter? If you are then your 95% there. Go to your telemetry screen at the end of a flight and you should see the maximum reading for each installed (and operational) telemetry device. Select the alarm option to the right and place a value in there which you want to alarm to trigger on.