Patent ID: 6986111
Filing Date: 2006-01-10
Classification: G05B

Abstract:
1. A self-diagnostic circuit for an I/O circuit system comprising a plurality of output digital channels which individually send control signals from a main controller to loads serving as objects to be controlled, and a plurality of input digital channels which input sensor signals to the main controller from a plurality of sensors attached to the objects to be controlled, tie switches which are normally in a nonconductive state and in a conductive state while making a self-diagnosis, respectively interposed between the plurality of output digital channels and the plurality of input digital channels, and self-diagnostic switches, which are normally in a conductive state and in a nonconductive state while making a self-diagnosis, respectively connected to power supply sides of the loads on the plurality of output digital channels, and ground sides of the sensors on the plurality of input digital channels, in self-diagnosis, the main controller outputting a digital self-diagnostic signal and receiving a return signal.