| 摘要 |
An alarm system has a controller unit (12) including a radio signal receiver and comprising a portable unit (16), such as a pendant, incorporating a radio signal transmitter and a keypad (18). The keypad (18) on the pendant (16) is operable to transmit system arm and disarm signals to the controller unit (12). The controller unit (12) receives signals from one or more sensor detectors (14) and on entering an alarm state is arranged to automatically dial out on the public switched telephone network to a predetermined destination. |
