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→La théorie
== La théorie ==
== La théorie ==
Most alarm systems follow a basic design. A switch closure (or opening) triggers action by a central monitor and the alarm generates some form of annunciation.
Most alarm systems follow a basic design. A switch closure (or opening) triggers action by a central monitor and the alarm generates some form of annunciation.
<small>{{underline|Note:}}<br />
L'unité de surveillance s'appelle "Central Monitoring Unit" en anglais. Vous pourriez donc rencontrer l'acronyme "''CMU''" ici et là sur le Net si vous prenez des renseignement sur le sujet.</small>
{{ADFImage|Trinket-Alarme-Base-01.jpg}}
{{ADFImage|Trinket-Alarme-Base-01.jpg}}
Switches can be normally closed or normally open. When they are triggered, they change state (closed goes open, open goes closed). The monitoring unit notices the change and if it meets criteria that it believes is an alarm, it annunciates.
Switches can be normally closed or normally open. When they are triggered, they change state (closed goes open, open goes closed). The monitoring unit notices the change and if it meets criteria that it believes is an alarm, it annunciates.
Annunciations can take as many forms as sensors. The stereotype alarm system has a very large horn to make an ear-splitting sound. But it can be much more subtle. The central monitor can alert a "silent alarm": making the alarm known in some way, either locally or far away. An example would be a text or SMS message on your phone stating an alarm has been triggered. The simplest alarm may only trigger a local alarm not designed to scare the intruder - this can be a nearby notification or it could be a record of alarm events for later review.
Annunciations can take as many forms as sensors. The stereotype alarm system has a very large horn to make an ear-splitting sound. But it can be much more subtle. The central monitor can alert a "silent alarm": making the alarm known in some way, either locally or far away. An example would be a text or SMS message on your phone stating an alarm has been triggered. The simplest alarm may only trigger a local alarm not designed to scare the intruder - this can be a nearby notification or it could be a record of alarm events for later review.
== Plusieurs senseurs, un broche ==
== Plusieurs senseurs, un broche ==