Autodialer alarm

An autodialer alarm, or community alarm as it is known in Britain when it is run by the County council, is an electrical device that usually has a push button transmitter which an individual may use to summon assistance to their location. These portable transmitters send a signal to the alarm unit. The transmitter is designed to be worn around the neck, on your wrist or clipped onto your clothing. Some brands offer additional methods of setting off the alarm such as a push button on the alarm unit itself, wall buttons or pull cords. Some alarms will go off automatically if they detect smoke, an intruder, a low room temperature or if the individual hasn't moved in a while.

A Community Alarm RF Pendant

Once the button has been pressed, the alarm unit will automatically contact a relative or friend or a special control center. With most alarm systems it is possible for the person who answers the call to hear and talk to the individual, although this is not necessary as the alarm has been raised by just pushing the button.

When the device transmits to a control center, personal information of the owner will automatically appear on a screen in front of the operator. They will usually try to speak to the individual, often via an intercom channel that is opened up when the alarm is activated, and if the individual needs help or they cannot get a reply, then they will arrange for someone to visit.

An alarm which dials directly through to a relative's or friend's house will usually be programmed to dial more than one number, to increase the chances of finding someone at home.

An autodialer alarm is different from an alarm autodialer, a part of the wall alarms.

Connection methods

There are five main interfaces on a community alarm base unit.

1. The electricity supply, this runs the unit and charges up internal batteries so the alarm works even if the mains has been off for a few hours.
2. Phone line: This is how the base station signals the alarm to the control centre or normal phone. When communicating with a control centre, the base stations identity is communicated to the control centre's computer system often using DTMF. Then the name and address as well as others bits of information stored on the control centres data base are displayed on the control centre operators screen so that she knows as much detail as possible about the source of the alarm. The base station also transmits the source within the house of the alarm so the operator will know if the pendant has been pressed or the button on the alarm or if a smoke alarm has been triggered.
3. Aerial to receive the alarm signal from the RF pendant.
4. Alarm button on base unit just in case the pendant has been lost.
5. Alarm contacts so that base unit can be connected to other detectors such as smoke or gas detectors.