Not sure what you are asking, what mode are you in?
you have to remember with this vent you set up the CPAP/PEEP first with the pressure display set to MIN, i would suggest in cpap mode, then you set up PIP with pressure display set to max in CMV is best mode. Remember after setup, if PEEP pressure is adjusted this the will be reflecte on you PIP so if you have a Peep of 4 and a pip of 20 and you then adjust your peep pressure to 6 you will automaticaly have a pip of 22.
when you set the pressures up make sure you min alarm is all the way down and your max is all the way up and the cycle fail is above your peep but not your pip so you dont get the vent dumping thinking is an over pressure.
I think you are getting an high alarm what is causing the vent to dump the pip and thats why your getting that peep, not sure need more info