Editing Security alarm (section)

== Components ==
[[File:Menvier TS690 Security Alarm Panel.jpg|thumb|upright|Alarm CPU panel with inputs and outputs]]
The most basic alarm consists of at least one sensor to detect trespassers and an alerting device to indicate the intrusion. However, a typical premises security alarm employs the following components:

* '''Alarm control panel''' ('''ACP'''), or simply '''panel''': The panel reads sensor inputs, tracks arm/disarm status, and signals intrusions. In a modern device, there are typically one or more computer [[printed circuit board|circuit board]]s inside a metal enclosure. Many newer networks often use sealed plastic boxes. Some also have their control units built-into the keypad or other [[user interface|human-machine interface]].
* '''Sensors''': In a security alarm, some sensors detect intrusions. Sensors' locations are at the perimeter of the protected area, within it, or both. Sensors can detect intruders by different methods.
* '''Alerting devices''' indicate an alarm condition. Most commonly, these are [[bell]]s, sirens, also and or flashing lights. Alerting devices serve the dual purpose of warning occupants of intrusion and potentially scaring off burglars.
* '''Keypads''': Keypads are devices that function as the [[user interface|human-machine interface]] to the system. In addition to buttons, keypads typically feature indicator lights, a small multi-character display, or both.

In addition to the system itself, security alarms often offer a monitoring service. In the event of an alarm, the premises control unit contacts a central monitoring station. Operators at the station take appropriate action, such as contacting property owners, notifying the police, or dispatching private security forces. Such alerts transmit via dedicated alarm circuits, telephone lines, or the internet.