The motion detector senses variations in infrared light, or heat. It detects any movement in a zone up to 5.5 metres (18 feet) away and in an arc 45° to the left and right. When someone walks past it, it senses a change in temperature and sends a signal to the smart base if your system is armed and in Away mode.
Pets can also trigger the motion detector, so don't let them loose in the area covered by the detector when your system is armed in Away mode.