| 摘要 |
PURPOSE:To prevent a device to be controlled from being transited to a different control from a set value due to a failure in a converter and to prevent shock to the device to be controlled, by providing a device which detects the failure of the converter with a prescribed rule. CONSTITUTION:A controller 2 gives a control signal in accordance with the increment and polarity between a reference value and a feedback amount from a converter 4, to a device 3 to be controlled. The controller 2 stores the control signal to a value at the point of time with a failure signal from a failed device detector 5. The device 3 returns a status signal to the controller 2 via the converter 4, which transmits the status signal to the controller 2 and the detector 5. The detector 5 classifies the signal into a continuous fundamental signal component and a sudden change signal component. If the sudden change signal is produced or the output of the converter is lost, it is decided as a failure in the converter and informed to the controller 2 and an alarm device 6. The controller 2 stores the output to the device 3 at a present value to protect the device 3. |
