Thank you for your answer Julien. I'm trying to find the way to create the ScheduleRuleset. It is possible to create a ScheduleRuleset using OpensStudio interface? Thank you

It's in the quick start guide for example. Go to schedule tab > Schedule and then click the green + at the bottom.

Thank you Julien. I added the Humidifying and Dehumidifying Setpoint Schedules and associate them to my single thermal zone in the "Thermal Zones" tab. I have some doubts in the way we can control the humidity with a Packaged Rooftop Heat Pump. What components realize the humidification/dehumidification of the zone? Should I have to add in the "Thermal Zone" tab a Dehumidifier-DX? If the solution is to add a Dehumidifier-DX in which node do we have to add the Setpoint Manager(minimum/maximum)? Thank you

This thread might be getting a bit out of hand, and ultimately this has nothing to do with OpenStudio. It's more a matter of EnergyPlus (and maybe a bit of general HVAC knowledge). I suggest you try to read up the Input/Output reference guide, and take a look at the numerous example files that ship with EnergyPlus. In the Example folder inside the EnergyPlus install folder, you'll find two HTML files that will help you locate which file to look at. here open Example Files - with object links and search for ZoneControl:Humidistat

Thank you for your suggestion Julien.