| 摘要 |
PROBLEM TO BE SOLVED: To improve reliability so that an output from an interface circuit connected to one of adjacent input terminals is used for the continuation of accurate control and an output from an interface circuit connected to the other input terminal is suitably used for the judgement of abnormality by setting up the current driving capacity of one interface circuit to a high level and that of the other interface circuit to a low level. SOLUTION: For instance, three interface circuits 12 to 14 are respectively connected to the adjacent input terminals 10a to 10c of a CPU 10. Current limiting resistances R12 to R14 are connected to the output stages of the circuits 12 to 14, the resistance value of the resistor R13 is set up to 100kΩe.g. and the resistance values of the resistances R12, R14 are set up to 1kΩe.g. If the outputs of the circuits 12, 13 are short-circuited, strong on/off formats appear in signals inputted to the terminals 10a, 10b and control similar to a state obtained before the short-circuit can be executed in the terminal 10a but the format of the terminal 10b is sharply changed from an analog signal to be originally inputted.
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