| 摘要 |
PURPOSE:To decide not only the trouble of an equipment itself but a so-called fail-safe trouble by checking whether or not the cumulative count number of pulses obtained at the trouble deciding time point is equal to the count value obtained in a normal mode of the equipment. CONSTITUTION:For instance, an additional circuit 4 which is used for decision of troubles has a trouble in such a state where the normal output is delivered and therefore the detection outputs (h) for decision of the working state are continuously delivered. Thus the synchronizing detection signals (k) are delivered in the same number as check pulses c-1, c-2... and the cumulative count value of a counting circuit 13 is set at '6' and not '3'. Therefore a trouble is confirmed. If the circuit 4 has a trouble in a state where AND circuits 9-11 are set at the side of a normal output, an OR circuit 12 has the output '0' or '1' continuously and not the pulse outputs like n-1, n-2.... As a result, the count value of the circuit 13 is equal to '0' or '1' and never to '3'. In such a case, the occurrence of a trouble is also confirmed. |
