| 摘要 |
In the known alarm system, the wire-line network is used for serially transmitting binary signals by means of a modulation. Such alarm systems consist of various components, to be designated as central station and component stations, which exhibit memories and comparison elements. In order to have good signal reception in spite of interference, it is proposed that the central station periodically outputs a message with at least one repetition whilst the components output a response successively in time in a first transmitting series and a repetition with the same content in a further transmitting series in a particular order. The components are synchronised with one another by clock generators and determine the signal-time areas of the received disturbed responses and messages bit by bit. These are added to form an area sum and compared with a predetermined threshold value after which the binary characteristic of the received signal bit is decided. After this response has elapsed, the central station begins with the next message and repetition.
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