Understanding home security components and options.
All electronic alarm systems include the master control panel, at least one keypad for arming and disarming the system, a selection of sensors (entry sensors at perimeter doors and windows plus motion detectors for areas inside the home), and a warning signal such as a siren and/or strobe lights.
Sensors are essentially magnetic switches that trigger the alarm whenever a door or window is opened. One part of the switch is installed on the door or window frame; the mating part attaches to the door or the window sashes. When the unit is opened, separating the parts, the interruption in current triggers the alarm.