| 摘要 |
PURPOSE:To continuously detect the abnormality of a control subject in an abnormal state of a function generator by detecting the abnormality even in case the output deviation between the function generator and an auxiliary function generator exceeds the reference value. CONSTITUTION:In case the characteristics of a function generator 1 and an auxiliary function generator 5 have changes during a long period of their applications, the position detection signal S2 has a change to a read position signal S1, for example, as shown by a broken line graph Lb. Thus the deviation of output is produced between both generators 1 and 2 due to the difference between the signal S1 and the position detection signal S10 of the generator 5. Then the function deviation signal S11 outputted from a function deviation computing element 6 is gradually increased with increased of said deviation between the signal S1 and the signal S10. If the signal 11 exceeds its limit value, an alarm signal S5 and a position lock signal S6 are outputted from an alarm 3. Thus the occurrence of abnormality is informed and at the same time the position of the control subject is fixed then. As a result, it is avoided that the abnormality of the control subject is continuously detected continuously in an improper state of the output of the generator 1. |
