INDICATOR VOLATILITY HISTORY Rascheke Connors, PLEASE HELP ME!

[alenero1]

Hello traders, I'm Alessandro from Italy, my interest is the forex market, right now I'm reading the best strategies Connors short, I have difficulty to find an indicator of historical volatility ratio 100 / 6 100 / 10, this indicator is shown in the volatility breakout strategies, when the volatility of short drops below 50% of the volatility of long-term periods triggered a signal of 100 allerta.Somebody know this indicator? my MetaTrader4 platform. THANKS To all
Sincerely
Alessandro Monti