Digital control system with error monitor operative upon starting system operation
First Claim
1. A digital control system including a microprocessor which among other functions, checks an actuator to be controlled by the system and an operation monitor, comprising:
- first means for resetting and initializing the control system;
second means for activating said first means in response to the onset of power supply to the control system;
third means for detecting malfunction of said control system and activating said first means when malfunction of the control system is detected;
fourth means, responsive to said first means being activated for applying a dummy load to said actuator and said operation monitor for testing the latter; and
fifth means, responsive to activation of said first means by said third means for disabling said fourth means.
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Accused Products
Abstract
A digital control system is provided with an error monitor system which applies dummy loads to an actuator and a monitor lamp in order to check the operation thereof. The digital control system also has a watch-dog timer responsive to a periodic signal produced as long as a microprocessor of the control system is operating normally. The control system is adapted to be initialized in response to the onset of power supply and in response to error signals from the watch-dog timer. A discriminator is provided in the control system to discriminate the cause of initialization of the control system. The discriminator enables the error monitor system when initialization due to onset of power supply is detected but not when initialization is due to errors detected by the watch-dog timer.
43 Citations
10 Claims
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1. A digital control system including a microprocessor which among other functions, checks an actuator to be controlled by the system and an operation monitor, comprising:
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first means for resetting and initializing the control system; second means for activating said first means in response to the onset of power supply to the control system; third means for detecting malfunction of said control system and activating said first means when malfunction of the control system is detected; fourth means, responsive to said first means being activated for applying a dummy load to said actuator and said operation monitor for testing the latter; and fifth means, responsive to activation of said first means by said third means for disabling said fourth means. - View Dependent Claims (2, 3, 4)
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5. An error monitor system for a digital control system controlling an automotive vehicle device, comprising:
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a microprocessor performing control operations for the automotive device in accordance with a preselected control parameter, said microprocessor producing periodic signals having a period shorter than a predetermined period as long as the microprocessor is operating normally; a first detector for measuring the period of said periodic signal and producing a first detector signal when the measured period exceeds said predetermined period; a second detector for detecting power supply to said microprocessor and outputting a second detector signal for a predetermined period of time in response to the onset of power supply; means for resetting the control system in response to either of said first and second detector signals and initializing the control system; and means for applying a dummy load signal to devices to be controlled by the control system, said dummy load applying means being responsive to said second detector signal to produce said dummy signal. - View Dependent Claims (6, 7, 8, 9, 10)
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Specification