| 摘要 |
<p>A building intercommunication system (10) comprising at least one outdoor station (11) and a plurality of indoor stations or intercom sets (14), wherein the outdoor station includes at least one keyboard (15), or the like, for selecting the individual indoor stations, transducers (16) for transceiving the audio signal, and a driver for an electric lock (17), and wherein each indoor station or intercom set (14) comprises at least one handset, a call transducer or buzzer, and a button (26) for operating the electric lock, the outdoor station and indoor stations being connected to each other by means of a line (12-12') having just two wires and with the interposition of junction boxes (13), each box handling a corresponding group (G) of intercom sets (14). The two-wire line (12) acts as a bidirectional bus over which the following elements travel: the power supply for all the devices connected to the bus, the data related to the intercom set (14) to be selected, the ring tone, the two simultaneously talking/listening audio signals, and the control of the electric lock (17). <IMAGE></p> |
