| 摘要 |
PURPOSE:To speed up repairing operation by recording faults of a controllers by contents, and thus knowing the cause immediately even when the controller is powered off. CONSTITUTION:A recording instrument 76 is supplied with three kind of inputs through a driver 75, i.e. a temperature input from a sensor 16 through an A/D converter 71 and a dynamic/static converter 72, a time input from a timepiece 74, and a fault input from a priority circuit 73. Only one track for a fault input recording part is provided to the recording instrument 76, so only one fault input is outputted from the priority circuit 73. The priority circuit 73 is supplied with the 1st order input from four decision making circuits in the figure, the 2nd order input from a heater decision making circuit 51a, and the 3rd order input from a subordinate temperature recording controller 26. When the 1st order input is supplied by one, recording is carried out regardless whether any other order input is present or not. Then, a decision on whether a break of electricity feeding is caused by a heater 13 or thyristor 12 is made on the basis of the difference in order between the heater fault input and thyristor fault input, so there is no confusion in finding its cause. |
