Patent ID: 6076172
Filing Date: 2000-06-13
Classification: G06F

Abstract:
A monitoring system for an electronic control unit of a machine or controlled object comprising:control means for carrying out a predetermined operation and outputting a program run (PRUN) signal having a predetermined cycle when the operation is carried out in a predetermined normal fashion;monitoring means for outputting a PRUN abnormality signal upon confirming that said PRUN signal is stopped for a predetermined time;reset pulse generation means responding to said PRUN abnormality signal by outputting a reset pulse for resetting said control means upon confirming that said PRUN abnormality signal is input thereto;fail determining means responding to said reset pulse by outputting a fail detection signal for making a controlled object carry out a fail safe function thereof upon confirming that said reset pulse is input thereto more than a predetermined number of times; andpower ON reset generation means for outputting a power ON reset signal for resetting said control means when a power supply voltage at a predetermined value is provided to said control means; whereinsaid fail determining means outputs said fail detection signal upon confirming that said power ON reset signal is input thereto and stops output of said fail detection signal upon confirming that said reset pulse is input thereto;said control means confirms that said fail determining means is outputting said fail detection signal after receiving said power ON reset signal and stops output of said PRUN signal; andsaid control means determines that said fail determining means is operating normally upon confirming that said fail determining means stops output of said fail detection signal after said control means halts output of said PRUN signal.