| 摘要 |
<p>Public alert and advisory systems for the communication of emergency and/or other information from one or more central locations to a plurality of remote locations, such as, by way of example, information regarding a nuclear accident and evacuation procedures. This system utilizes conventional programming stations such as AM, FM or TV stations, central transmitting equipment, with the emergency information being modulated by a second modulation technique differing from the first modulation technique for the ordinary programming so that conventional manually operated programming receivers will not be responsive to the emergency information. The receivers of the system however, are responsive to the transmitted emergency information, so as to sound a warning alarm, display codes relating to evacuation or other information and/or receive and present audio information depending upon the specific configuration of the system. Normally the remote receivers are given recognition codes so that the receiver may be given different emergency information, either on an individual or on a group to group basis. Fault detection is provided by configuring the remote receivers to automatically provide a fault indication if not periodically reset by the communications link. A unique telephone link, also disclosed, can be used for reliability testing or for ordinary data communication. Various embodiments and features are disclosed.</p> |
