DATA RECORDING DEVICE

PURPOSE:To record a measurement signal used to analyze the cause of abnormality by providing an abnormality detecting circuit which detects abnormality of each measurement signal from a specific combination of plural measurement signals and preserves storage and constituting an abnormal signal according to a purpose. CONSTITUTION:A combination of abnormal signals is set is a logic circuit 22 according to a purpose. Then,. an analog signal and a contact signal are inputted to a central processing unit 14 through input units 10 and 12 respectively. Those signals are processed and stored in an external storage device 16. In such a case, the analog signal and contact signal and other signals are inputted to the circuit 22 and processed by a combination of logical elements such as AND and OR to constitute an abnormal signal used to analyze sudden abnormality. Data of various measurement signals before and after a stored abnormal position are analyzed to investigate the cause of a fault due to the sudden abnormality.