| 摘要 |
PURPOSE:To quickly and surely detect the production of abnormality at a transmission side, by receiving a prescribed data transmitted from a transmitter, by a receiver mounted on a mobile body and displaying abnormality when a consecutive time of a prescribed data or a level value exceeds a prescribed setting time or a setting value. CONSTITUTION:A preset data is transmitted from transmitters 41-4n of a stationary station within a transmission period and a consecutive time of a prescribed data or a level received by the receiver 7 mounted on the mounted body 5 is compared with a prescribed set time or a setting value. Then the abnormality display is applied when the fault is consecutive in excess of the setting time. Thus, the fault of the transmission side or a radio wave fault is detected easily and surely to prevent the hindrance of traveling of the mobile body. Since the data from the transmitters 41-4n to the receiver 7 is transmitted in radio, the effect of increasing the degree of freedom to expand the data transmission range is obtained in comparison with data transmission utilizing light or magnetism. |
