| 摘要 |
Device in an alarm system, notably a security, operational, or break-in alarm system which includes a transmitter (1) with an automatic dialling unit (2), one or more receivers (3) which can be called through the automatic dialling unit (2) in the transmitter via the switch and line system in the telephone system. A voltage detection device (4) is connected a subscriber or connection line (L). When voltage on the line falls below a predetermined value because of a short-circuit, open circuit, or extension error on the line or another error in the system, the voltage detection unit initiates an error signal. With this error signal, a local alarm for the problem is initiated and/or a further dialling unit (6) is initiated which via a fixed or dial-up connection (L') in the telephone network is intended to transfer information about said error to one or more of the said receivers (3).<IMAGE> |
