| 摘要 |
<P>PROBLEM TO BE SOLVED: To make a system for transmitting an accurate time from a host device to a slave device by a radio wave affected hardly by an attack radio wave and a disturbance radio wave. <P>SOLUTION: The slave device 3a of the highest rank is provided with a clocking part 34, a control part 33 for executing data processing using a clocking time, and for correcting the clocking time of the clocking part 34, based on time information received from a host device, a receiver 31, a transmitter 38 for radio-transmitting the time information for correcting the time of the lower slave device, a radio wave intensity measuring part 61 for measuring intensity of a reception signal, a radio wave intensity storage part 62 for storing the measured intensity, an abnormal radio wave determining part 63 for determining the reception signal as an abnormal signal, when the intensity of the reception signal in this time is outside a standard deviation value in averages of the plurality of stored intensities, so as to prohibit the correction of the clocking part 34 and the transmission to the lower device, and an abnormal state notifying part 64 for notifying the presence of abnormality to the host device. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
