A control device includes an apparatus controller that is connected to at least one apparatus and includes a first memory which stores data for controlling the driving of the apparatus and data indicating a state of the apparatus and a reading and transmitting unit which reads each data item stored in the first memory and transmits the read data, a main controller that includes a central processing unit, a second memory, and a writing unit which writes the data transmitted from the apparatus controller to the second memory, and a full-duplex serial bus that connects the main controller and the apparatus controller. The reading and transmitting unit and the writing unit operate such that each data item stored in the first memory is read, transmitted, and stored in the second memory in a cycle equal to or less than a count cycle of a system timer.