| 摘要 |
Disclosed is a railway signaling system for controlling a load. In accordance with the teachings of this invention, the system comprises a first autonomous controller and a second autonomous controller which is redundant with the first controller, each controller connectable to the load such that there is no single point of failure. The first and second controllers operable in either an on-line mode wherein both power outputs provide power to the load or an off-line mode wherein a single power output does not provide power to the load. On-line controllers monitor current therethrough. When both controllers are on-line, the current between the two controller is imbalanced up to a threshold limit, if the threshold limit is exceeded by one controller, that controller will go off line, and if the first controller is off-line and the second controller is on-line, the second controller monitors output voltages of the off-line controller to ascertain that the output voltages are zero.
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