To realize a system which can operate the main body of a display device for control even if an operator is away from the main body of the display device.

The communication processing part 41 of a programmable display device 12 communicates with a remote controller 31, which is provided separately from the programmable display device 12, to transmit status information via free space, and then the control part 35 of the remote controller 31 displays an operation screen on the display 32 of the remote controller 31 based on the status information. When an operation key 33 of the remote controller 31 is operated, the communication processing part 34 of the remote controller 31 transmits operation information indicating the operation to the programmable display device 12, and the HMI processing part 25 of the programmable display device 12 controls a device based on the operation information as in the case of the touch panel 24 of the programmable display device 12 being operated.