Fault diagnosis apparatus and fault diagnosis method of multi-channel analog input/output circuit

• Main Authors: NISHIOKA ATSUSHI, KASAHARA TAKENORI, OOTANI TATSUYUKI, KIYOFUJI YASUHIRO, KUBOTA MANABU, FURUTA YASUYUKI, YOSHIDA KATSUMI, NAGAYAMA SYUICHI, TANAKA HIDECHIYO, TERAE HISASHI, KAWAWA FUJIYA, ISHIKAWA MASAKAZU
• Format: Patent
• Language: English
• Published: 26.02.2013
• Subjects: BASIC ELECTRONIC CIRCUITRY; CALCULATING; CODE CONVERSION IN GENERAL; CODING; COMPUTING; CONTROL OR REGULATING SYSTEMS IN GENERAL; CONTROLLING; COUNTING; DECODING; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRIC DIGITAL DATA PROCESSING; ELECTRICITY; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS ORELEMENTS; PHYSICS; REGULATING; SIGNALLING; TESTING; TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHICCOMMUNICATION; TRANSMISSION SYSTEMS FOR MEASURED VALUES, CONTROL OR SIMILARSIGNALS

A fault diagnosis apparatus and method capable of simultaneously detecting the fault of a multiplexer and the fault of an A/D converter and isolating and identifying causes of these faults, the multiplexer and the A/D converter being used in a multi-channel analog input/output circuit. Test-voltage values are inputted from a diagnosis-voltage input unit into the multiplexer and the A/D converter constituting an analog-signal conversion unit, the multiplexer having plural channels, the A/D converter converting outputs from the multiplexer into digital signals, the test-voltage values being different from each other for each channel of the multiplexer. Comparisons are made between the digital voltage values and the test-voltage values inputted, the digital voltage values being outputted for each channel of the multiplexer. From this comparison result, it is judged whether the multiplexer is at fault or the A/D converter is at fault.