Device control using data communication

A control method of a data processing device which is connected with a data supply device for performing predetermined data processing and includes:

• a communication control unit for controlling communication with the data supply device:
• a data processing unit for performing the data processing based on input data received from the data supply device;
• and
• a device control unit for performing predetermined processing in correspondence with command data received from the data supply device based on the command data,
• the control method comprising:
• (a) receiving the input data and the command data each of which is contained in a packet having a common fixed length from the data supply device by the communication control unit;
• (b) supplying data contained in the reception packet received from the data supply device to the device control unit by the communication control unit when an identification part at a predetermined position in the reception packet is set at a predetermined command identification value indicating the command data;
• (c) supplying the data contained in the reception packet to the data processing unit by the communication control unit when the identification part is set at a value different from the command identification value;
• (d) using the remaining part in the reception packet other than the identification part as the command data by the device control unit;
• and
• (e) using the remaining part as the input data by the data processing unit.

A communication system between a data supply device and a data processing device connected with the data supply device for performing predetermined data processing,

• the data processing device performing the data processing based on input data received from the data supply device and performing predetermined processing in correspondence with command data received from the data supply device based on the command data,
• the data supply device supplying the input data and the command data each of which is contained in a packet having a common fixed length to the data processing device,
• the data supply device performing the processes of:
• (a) setting an identification part at a predetermined position in the packet at a predetermined command identification value indicating the command data and storing the command data in a remaining part in the packet other than the identification part for transmitting the command data;
• and
• (b) setting the identification part at a value different from the command identification value and storing the input data in the remaining part for transmitting the input data,
• the data processing device performing the processes of:
• (c) using the remaining part in the reception packet received from the data supply device as the command data when the identification part in the reception packet is set at the command identification value;
• and
• (d) using the remaining part in the reception packet as the input data when the identification part in the reception packet is set at a value different from the command identification value.