摘要 |
A security installation at one Site has remote sensors which detect intrusion, fire, etc. and transmit corresponding signals by radio to a master station. Similar installations are provided at other Sites. The sensors of each Site precede their data signals with an access code which is particular to that Site and prevents their signals being received by the master station of any adjacent Site within radio range. When a new installation is to be installed at a new, adjacent Site, an arbitrary value is initially selected for its access code and the master station there transmits a special code to all adjacent Sites. In response to this special code, the master station in each such adjacent Site transmits its own access code back to the new installation, where it is compared in value with the arbitrarily selected access code. The latter is automatically changed until it becomes different from that of any and all adjacent Sites. The remote sensors of the new installation are then set to this value.
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