| 摘要 |
<p>PURPOSE:To prevent the titled device from being subject to bad influence even when an abnormal test signal is impressed by inputting a test signal for abnormality diagnosis outputted from a signal generating means connected to each control device to a signal selecting device for selecting a proper input signal. CONSTITUTION:A control device 1A outputs a measuring signal for a sensor and also outputs a signal (a) for controlling the opening of valves 13A-13C and the signal (a) is inputted to a majority decision device 10A through a change-over switch SW or the like. The device 10A selects at least two coincident signals output three input signal as a correct signal and outputs the signal. In case of diagnosing the existence of abnormality in the device 10A, the switch SWA is switched and a test signal S is outputted. A diagnosis device 2A compares detecting signals 16A-18a measured by signal detectors 7A-9A with each other. When the patterns of these detecting signals are equal, they are judged as abnormal signals. Since the device 10A is a signal selecting means, the device 10A can be prevented from being subject to the bad influence of an abnormal test signal.</p> |
