A processing module to use for a processing system having a plurality of processing modules connected via a communication line is comprising mounting position information for the processing module in the communication line; a unique logical address to indicate the processing module; a database to correspond with a physical address of the processing module in the communication line; a position identification device to identify the mounting position information in the communication line of the processing module; a unique/physical address conversion device to fetch the physical address corresponding to the unique logical address from the database using a data packet having the unique logical address as a destination; and a position/physical address conversion device for searching for the physical address from the mounting position information.
