| 摘要 |
PURPOSE:To improve the safety of the keyless security system by successively changing the variable codes of transmitting data according to the equal difference of a random numeral decided for each cycle. CONSTITUTION:At a transmission unit 1, corresponding to a command signal, a control part 13 reads the variable code corresponding to the number of times of manipulations from a storage part 13b, forms the transmitting data by generating and synthesizing a command code and an ID code including the variable code at an ID code setting part 13a and transmits those data through a transmission circuit 15 after a carrier wave is modulated. At a reception unit 2, after these transmitted data are demodulated and reproduced by a reception circuit part 22, those data are supplied to a security control part 23. A comparative deciding part 23a energizes a code updating part 23d and supplies the updated signal to a storage part 23c, the correspondent variable code is read out, transmitted to the comparative deciding part 23a and compared with the ID code of the reproduced transmitted data and only when they are matched, the reproduced transmitted data are transmitted to an operation control part 23b. |
