TROUBLE DIAGNOSING DEVICE

摘要

PURPOSE:To decide an input signal that is presumed as the factor of the output abnormality by comparing the timing of the state change of the input signal with the generating timing of the output abnormality. CONSTITUTION:An input/output data storing mechanism 104 extracts the actual value of each input/output signal of the sequence received from an input/output memory 106 and stores these values in a history memory 107. An automatic input/output connection retrieving part 102 checks a program memory 105 storing a sequence control program and extracts each output and its related input signal. An automatic stored data retrieving part 103 checks the history of the input signal extracted by the part 102 via the memory 107 and detects the input signal having a state change. A repetitive retrieval deciding mechanism 110 decides the factor of the abnormality from the timing of the detected input signal. Thus, it is possible to automatically retrieve the input conditions for the factor of the abnormality and to improve the trouble diagnosing efficiency.