| 摘要 |
An electronic system, preferably a radio system, has at least a main active unit 1 and a standby or reserve unit 2 which can be switched to when there is a fault with the main unit. In the invention, each unit is designed to detect a fault condition in itself and to trigger a substitution in response to such detection. In units including a transmitter and a receiver, the switching may apply to just the transmitter or the receiver. In a preferred embodiment, each unit monitors the performance of different parts of itself and applies scores accordingly (figure 2). The overall score of each unit can then be compared and the unit found to be performing best, selected for switching to. The scoring may incorporate a score related to a time period or amount of use to cause periodic switching even when there is no fault. This aims to overcome the problem where during long periods of non-use, faults can develop and go unnoticed in the reserve or backup unit 2. Thus, with each unit being able to detect faults and trigger substitution, there is no need for a separate change-over unit and this avoids the potential problems that can arise if the change-over unit itself malfunctions. The invention is particularly applicable to backup for air traffic control radio systems. |
