| 摘要 |
PROBLEM TO BE SOLVED: To decide that a circuit is defective with high accuracy by subtracting a value specified times as high as the value of a monitor signal from the sum of respective phase currents superposed with the monitor signal through a superposing means and comparing the absolute value of subtraction results with a predetermined alarm value. SOLUTION: A digital filter 50 subtracts respective digital data (monitor signal IM+K5 ) from a digital data and extracts a basic wave. A section 52 operates a value SUM indicative of the extent of detect of an analog input circuit based on a digital data distributed at a data distributing section 49. A section 53 compares the defect decision value SUM with a predetermined alarm value ε and decides that the analog input circuit is defective when the defect decision value SUM is larger than the predetermined alarm value ε. More specifically, a value three times as high as a monitor signal IM is subtracted from the sum of respective phase currents superposed with the monitor signal IM and the absolute value of subtraction results is compared with the predetermined alarm value ε thus deciding whether the circuit is detective or not. |
