wow, it looks great. Thank you for your time. I will try to understand it tomorrow.

Believe or not but I really have two exact same trades at the exact same price and I don't want to - this is a reason why I need a condition to prevent it. Alternatives you suggested are not helpful for this purpose. So let me ask once again: How can I check if the price I want to open a new trade at is already "occupied" or not by the same trade placed before. Another trade (sell or buy with another lot size) can be open at the same price, but not the same one.

many thanks!

No, I'm not looking for "no trade is running" block.
I don't care how many trades are running, I just don't want 2 or more same trades be running IF they have been executed in the same price. I explained example above

Hi,
I would like to create something like that:

Once per tick > condition1 > condition2 > CONDITION3 > buy now (or sell now, doesn't matter)

The chain should pass through CONDITION3 only if there is no same trade yet - for the same amount of lots at the same price. For example if EA placed buy order as instant execution (EURUSD, 0.1 lots, 1.12345, 15:00) and now condition1 and condition2 are fulfilled as well only with one difference – it is one hour later (EURUSD, 0.1 lots, 1.12345, 16:00), condition3 will not be fulfilled because the same trade already exist from 15:00 and it didn't achieve S/L or T/P yet. I just don't want to have 2 or more same trades executed in the same price in different times, trades with different lot size can be executed in the same price, they just must be different from each other in something, not only in time of execution.
How to do it?

sorry for my english, I hope you understood.
Thanks for help.