This control device is connected to a master device and controls a drive target on the basis of the content of communication with the master device, and includes a communication unit which periodically transmits to and receives from the master device first information, which is information relating to control of the drive target, and second information, which is information relating to safety; a first processing unit which controls the drive target by processing the first information; a second processing unit which, by processing the second information, performs processing to ensure safety of the drive target; and an abnormality determining unit which determines that an abnormality has occurred if both the first information and the second information have not been processed within a prescribed period.