METHOD FOR TRANSFER OF NOTICES FOR CENTRALISED SECURITY SYSTEMS Russian patent published in 2009 - IPC G08B25/10 

FIELD: radio engineering.

SUBSTANCE: at protected object they generate and send a serial binary code of notice with number of discharges M with a permanent duration of T_bit symbols to centralised security point (CSP). When the first symbol of notice is sent, random or pseudorandom frequency F_r is used, and when the second symbol is generated - frequency F_r +ΔF, where ΔF is a fixed interval. As transferred logical symbol changes, frequency is smoothly tuned from F_r to F_r+ΔF or from F_r+ΔF to Fr. In CSP filters are used to separate sections of channels with pitch that is K integer number less than AF interval. In CSP signal is received with a notice code at least in one of channels. In each channel they define P functions of notice for the time of T_bit with even shift of the moment of each function definition completion by interval T_bit/P-Function with matching moments of their definition completion, compare to each other and conditionally establish that the first of logical symbols is received in the same channels, for every of which value of received signal function exceeds value of threshold level, and the second of symbols - in remaining channels. Sequences that consist of M discharges of conditionally established symbols in each channels and for each of moments of function definition completion, they compare it with notice codes permissible for reception.

EFFECT: improved reliability, capacitance, distance and economic efficiency of security system.

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