Ok Etzel I found the subject, I answered to you on the Help esk so I'll paste my answer here:
Hello Attila,
The phones and Out outputs are working simultaneously, so you can have the Output going to the FOH and the Phones to a personal monitor.
They are driven by the same level control (output volume) so I would advise to set the volume to what is asking FOH, then adjust on your personal monitor.
Let me know if I can be of any further help.