| 摘要 |
PROBLEM TO BE SOLVED: To improve communication performance without imposing a burden on a transmitter-receiver as much as possible. SOLUTION: A transponder 20 is contained in a key 19A, when a power signal is sent from a vehicle side controller 12, the transponder 20 is activated to decide a command content of the power signal and sends a response signal to the controller 12. In the case of this structure, the transponder 20 measures data length from the controller 12, decides the fluctuation of its own clock frequency based on the measurement result and sends an error signal to the controller 12 when it detects the fluctuation of the clock frequency. Then, because the controller 12 corrects data length and resends it to the transponder 20, communication performance is improved without providing the transponder 20 with a complicated time correction feature. |
