Abstract: An external control FPGA device includes a command receiving terminal configured to receive command data, a control outputting terminal configured to output a functioning control signal, and a plurality of FPGA connection terminals, and a data processing FPGA device that transmits a control command from an external command data receiver to a control signal outputter. The data processing FPGA device is connected to one of the plurality of FPGA connection terminals through a data processing line that is independent of a command transmission pathway including an external command data receiver, a command data line, the external control FPGA device, a functioning control signal line and the control signal outputter. The data processing FPGA device inputs data that is to be processed from the external control FPGA device through the data processing line, and outputs the processed data to the external control FPGA device.