A 2-minute bar is formed by two 1-minute bars.
- On the first 1-minute bar the 2-minute the signal is not shown (the one of the previous 2-minute bar is, if any).
- On the second 1-minute bar the 2-minute bar is closed, so the signal is shown, thus it can be used to enter at market. Also on the first 1-minute bar of the next 2-minute bar the previous signal is still active, since the 2-minute bar is not closed, yet.
Using eXcel makes it simpler to show what I mean (see pic X).