FAULT DIAGNOSTIC SYSTEM OF DECENTRALIZED CONTROL SYSTEM

摘要

PURPOSE:To make it secure to disconnect a station by improving the detection rate of faults of a microprocessor by making a fault diagnosis by supplying as an interruption signal a signal that shows a change in normal operation signal. CONSTITUTION:Normal operation signal 6 of control station 3 connected by loop- shaped communication path 1 is generated by permitting fault detecting circuit 5 to receive input signal 7 obtained from communication path 1 through photocoupler 9, output signal 8 to communication path 1 and normal operation signal 16 from microprocessor 10 and inputted to relay 4 to put relay contact 4 into operation. Normal operation signal 16 is inputted to one-shot multivibrator 50 and when the signal changes within the time interval determined by the time constant of this circuits, the output signal 17 is held in state ''1'' and then inputted to the terminal IRQ as interruption signal 18 to microprocessor 10.