Emergency call system.

摘要

A speech emergency call system comprises a central control unit (CCU); a system cable (SC) connected to the central control unit; a plurality of speech modules (SM) each capable of handling two-way speech communication, all the speech modules being connected in parallel to the central control unit by the system cable; each speech module having an associated call initiator and means for transmitting a unique identity code from that speech module to the central control unit when a call is initiated from that speech module; a plurality of master units (MU) each having a unique distinguishing code, each master unit comprising means whereby it is connectable to the system cable, alerting means capable of response to a call initiated from a speech module and two-way speech communication control means; the control unit including recognition means for recognising the identity code of any calling speech module, and routing means for initially routing all calls from a first group (Z1) of speech modules as recognised by said recognition means to a first one (MU1) of said master units, and for initially routing all calls from a second group (Z2) of speech modules as recognised by said recognition means to a second one (MU2) of said master units. An interface unit (IF) is connected between the central control unit and a line of the public telephone network (PTN); the interface unit including autodialling means for automatically dialling a telephone number. The master unit and the central control unit include emergency call means operative to cause an outgoing call to be autodialled over the public telephone network and for the master unit to be placed in two-way speech communication once the outgoing call has been connected.