A communication control device includes an authentication login information storage unit that stores therein authentication login information. When a terminal device connects to a first communication port among a plurality of communication ports, the communication control device compares login information received from the terminal device with the authentication login information, and if they match, the communication control device outputs a command received from the terminal device. A control device includes an authentication unique information storage unit that stores therein authentication unique information. When the communication control device outputs the command received from the terminal device, the control device compares the unique information of the terminal device with the authentication unique information, and if they match, causes a processor to perform only a process of reading control information according to the command received from the terminal device.