| 摘要 |
The system has an electronic receiver/controller and a remote actuator/transmitter incorporating an encoder having a set of different codewords corresponding to the unlocking signal, sequenced in cyclic order (1,2,...x,...,n). At each actuation, one of these codewords is transmitted, in sequence, the x-th actuation transmitting the x-th codeword. The receiver has a decoder, which counts the transmissions and only converts the x-th transmission into the unlocking signal, releasing the electronic controller if it is the x-th codeword, these cycles continuing until x=n and then returning to x=1 and recommencing. If synchronism between the encoder and decoder is disturbed, it is restored by a signal from an auxiliary encoder having a set (m) of different, auxiliary, sequenced codewords acting as synchronisation signals. When the transmitter is specially actuated, one of these auxiliary codewords is transmitted, in sequence, the x-th actuation generating the x-th auxiliary codeword. An auxiliary decoder in the receiver counts the transmissions and converts the x-th auxiliary codeword on receipt into the unlocking signal, bringing about synchronisation and also switching the receiver to the (x+ 1)th auxiliary codeword (which the transmitter is prepared to emit), until at x=m the cycle recommences at 1. |
