| 摘要 |
PROBLEM TO BE SOLVED: To effectively prevent erroneous operation by providing a cancel means cancelling a received marker signal when a predetermined signal is not received while a train advances by a predetermined distance after receiving the marker signal sent from a marker ground slave. SOLUTION: The condition that two frequency change frequencies, namely, a marker frequency change frequency (f2) and a frequency change frequency (f3), are received until a train advances by a fixed distance is required to validate a combination of the marker frequency change frequency (f2) and the frequency change frequency (f3) or a combination of the frequency change frequency (f2) or (f0). If two signals are not received within a fixed distance, a signal of the received marker frequency change frequency (f2) is reset (cancelled). Consequently, even if ground slaves are provided in close proximity, it is possible to prevent erroneous operation effectively. |
