If you BarPeriod is 1440, then only 1 trade can be generated per day, usually.
If you have a shorter BarPeriod, perhaps you can check the various trade stats for trade or no trade in the current bar.
http://zorro-project.com/manual/en/winloss.htmOr you can use a global variable with the date of the last trade, if today=lasttradedate, then don't enter another trade.