You seem to be setting a limit. A stop entry requires a positive value.

Quote:
Entry

Enter the trade only when the price reaches a certain value at the next bar (default = 0 = enter at market). The value can be given either directly as an Ask price, or as a distance to the current close price. A positive price or distance constitutes an entry stop, a negative price or distance an entry limit. An entry limit buys when the price is at or worse than the limit; it increases the profit of the trade as it buys at a better price. An entry stop buys when the price is at or better than the limit; it reduces the profit, but enters only when the price moved in favourable direction, and thus acts as an additional trade filter.