Abstract: A master device according to this disclosure which communicates with a plurality of slave devices to share cyclic data includes: a configuration information acquiring unit to acquire a phase difference of each of the slave devices determined based on a number of other slave devices to be relayed when the each slave device communicates with the master device; and a transmission timing determining unit to calculate a hop count from a number of other slave devices to be relayed when the each slave device communicates with the master device or another slave device based on the phase difference acquired by the configuration information acquiring unit and to determine a transmission timing for each slave device to transmit the cyclic data in such a way that communications with a same hop count are performed at a same timing by the plurality of slave devices.

Abstract: A master device according to this disclosure which communicates with a plurality of slave devices to share cyclic data includes: a configuration information acquiring unit to acquire a phase difference of each of the slave devices determined based on a number of other slave devices to be relayed when the each slave device communicates with the master device; and a transmission timing determining unit to calculate a hop count from a number of other slave devices to be relayed when the each slave device communicates with the master device or another slave device based on the phase difference acquired by the configuration information acquiring unit and to determine a transmission timing for each slave device to transmit the cyclic data in such a way that communications with a same hop count are performed at a same timing by the plurality of slave devices.