Will my alarm go off if I have motion detectors and my system is armed in stay mode?

No, your alarm system will not be triggered by motion detectors when your system is in "stay mode".

In Stay Mode...
your security system deactivates all motion detectors because it knows you will be moving around inside the house. The purpose of this arming mode is to allow residents to move around freely inside the house while still providing security through activated perimeter devices, like door/window contacts and glassbreak detectors, which protect the home from intruders.

In Away Mode...
Motion detectors are activated. That way, any movement inside the house will trigger an alarm, because no one is supposed to be inside the house while you're away in the first place.

Similar Products:
5853 Glassbreak Detector
5800PIR-COM Motion Sensor