In ECN accounts, the Margin Call is triggered when the Margin Level (Equity to Margin ratio) is less than 100% (i. e. the equity of your trading account is equal to the margin used to open the positions).
A position is stopped out (closed by broker automatically) when the Margin Level of an account is less than 50% (i. e. the equity is less than 50% of the margin used to open a trade).