| 摘要 |
PROBLEM TO BE SOLVED: To enable a master unit to efficiently gather data from each terminal by multi-hop communication in a network having a tree structure configured by the master unit and a plurality of terminals connected in multiple stages.SOLUTION: A master unit 1 stores an identifier N1 of itself and an identifier N2 of a one-stage-lower terminal 2-1, and transmits a data gathering command to the terminal 2-1. Terminals 2-1 to 2-5 store an identifier of itself, an identifier of a one-stage-upper master unit or terminal, and an identifier of a one-stage-lower terminal, and gathering object data. When receiving the data gathering command, the terminals 2-1 to 2-5 create a gathering table and stores the identifier of the one-stage-lower terminal and transmits the data gathering command to a terminal with one identifier in the gathering table. The terminals 2-1 to 2-5 delete the gathering table according to data gathering from a lower terminal, and adds the identifier and data of the lower terminal and the identifier and data of itself to the data gathering command and transmit them to the upper terminal or the master unit as a response to the data gathering command. |
