Patent ID: 7058774

Claim:
A data backup method used in a system having a plurality of data processors connected to each other through transmission lines, each data processor comprising a data processing functional part, a data accumulation functional part, and a data communication functional part, wherein the data accumulation functional part stores predetermined processing object data, first data, second data, and third data, the first data indicating a number or code to identify the corresponding data processor, the number or code being assigned to each data processor, the second data indicating a group to which the corresponding data processor belongs, the third data indicating the relationships between the numbers or codes assigned to the respective data processors and at least one of the groups, the data communication functional part recognizes the first to third data, and the data communication functional part recognizes the third data stored in the data accumulation functional part, so that the data processors, recognized as belonging to the same group, transmit and receive the stored processing object data to/from each other and store the received processing object data in the respective data accumulation functional parts.