Patent ID: 7782766

Claim:
A data collection system comprising a base station, at least one upstream module being directly subordinate to the base station, and at least one downstream module being directly subordinate to the upstream module, which are connected via a network, wherein: the base station includes: a section for transmitting a first data collection request signal containing ID of the base station to the upstream module; a section for receiving a second data collection acknowledgement signal from the upstream module, the second data collection acknowledgement signal containing ID of the upstream module and measured data obtained by each module; and a section for compiling the measured data; the upstream module includes: a section for receiving the first data collection request signal from the base station; a section for transmitting a second data collection request signal containing the ID of the upstream module to the downstream module; a section for obtaining measured data through a sensor; and a section for transmitting the measured data to the base station as the second data collection acknowledgement signal; the downstream module includes: a section for receiving the second data collection request signal from the upstream module; a section for obtaining measured data through a sensor; and a section for transmitting the measured data to the upstream module as a first data collection acknowledgement signal; the second data collection request signal is transmitted to the base station simultaneously with the transmission of the second data collection request signal to the downstream module, and the base station regards the second data collection request signal as ACK for the first data collection request signal; when receiving the first data collection acknowledgement signal, the upstream module regards the first data collection acknowledgement signal as ACK for the second data collection request signal; and the second data collection acknowledgement signal is transmitted to the downstream module simultaneously with the transmission of the second data collection acknowledgement signal to the base station, and the downstream module regards the second data collection acknowledgement signal as ACK for the first data collection acknowledgement signal.