Abstract: In a control apparatus which transmits/receives data from a central processing unit via a serial transfer channel to a communication control unit, and groups/distributes data of input/output units from the communication control unit via a parallel transfer channel, the control apparatus initiates a diagnosing unit of the parallel transfer channel in response to an instruction issued from the central processing unit, and diagnosis the input/output units subsequent to the diagnosis of the transmission channel. Data input/output timing of the input/output unit is also instructed from the central processing unit, so that the central processing unit can suppress lowering of response speeds caused by the diagnoses, and can maintain the periodicity of the data input/output.

Abstract: A programmable electronic controller in which one central arithmetic processing unit and a plurality of input devices and output devices are connected by means of a parallel bus, the controller being basically configured to activate a self-diagnostic function and a diagnostic test of the input devices and the output devices with an instruction from a microprocessor of the central arithmetic processing unit; and to judge the result with the microprocessor of the central arithmetic processing unit, by using the microprocessor installed in the central arithmetic processing unit also as a processor for tests (diagnostic tests) of the self-diagnostic function of the input devices and output devices and conducting tests of the self-diagnostic function of the plurality of input devices and output devices with the central arithmetic processing unit.

Abstract: A control device diagnoses the operation of a bus arbiter that mediates bus usage requests output by multiple devices in the control device to satisfy both responsiveness and safety. A diagnostic module, implemented as an external diagnostic module, monitors signals related to the arbiter mediation and, if an abnormality caused by a signal sticking condition or an abnormality in a mediation control unit is detected, stops data transfer safely to prevent safety data from being output incorrectly.

Abstract: In a control apparatus which transmits/receives data from a central processing unit via a serial transfer channel to a communication control unit, and groups/distributes data of input/output units from the communication control unit via a parallel transfer channel, the control apparatus initiates a diagnosing unit of the parallel transfer channel in response to an instruction issued from the central processing unit, and diagnosis the input/output units subsequent to the diagnosis of the transmission channel. Data input/output timing of the input/output unit is also instructed from the central processing unit, so that the central processing unit can suppress lowering of response speeds caused by the diagnoses, and can maintain the periodicity of the data input/output.

Abstract: A programmable electronic controller in which one central arithmetic processing unit and a plurality of input devices and output devices are connected by means of a parallel bus, the controller being basically configured to activate a self-diagnostic function and a diagnostic test of the input devices and the output devices with an instruction from a microprocessor of the central arithmetic processing unit; and to judge the result with the microprocessor of the central arithmetic processing unit, by using the microprocessor installed in the central arithmetic processing unit also as a processor for tests (diagnostic tests) of the self-diagnostic function of the input devices and output devices and conducting tests of the self-diagnostic function of the plurality of input devices and output devices with the central arithmetic processing unit.