| 摘要 |
PURPOSE:To flicker an indicator as long as the main controller and interruption controller are functioning normally by causing the interruption controller to interrupt the repetitive control motions of the main controller at nearly regular interval to actuate the indicator based on the preset indicator switching data. CONSTITUTION:When the main program (a) and interruption program (b) are functioning normally, an LED 17 is flickered at nearly regular intervals. If an infinite loop should happen in the program of CPU 11 at a certain location in the main program (a) or interruption program (b) due to a malfunction in one way or another, the following interval illumination flag for the LED is fixed either to 1 or 0 because the routine A of the main program (a) is not executed repeatedly, causing the LED 17 to continue either ON or OFF. Therefore, a service technician of air conditioner can readily tell the presence or absence of malfunction in the CPU 11.
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