Control Apparatus, Control Method and Control Program

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.