Power Line Communication Device

A power line communication device that will control multiple sub-units without exception via broadcasting from a main unit is disclosed. The power line communication device controls the machines connected to each sub-unit from a main unit using power line communication. The power line communication device has a controller, a main unit superimposing control signals containing data from said controller onto the power line, and multiple sub-units controlling the connected machines by receiving control signals being broadcast from the main unit. Each sub-unit is set up to be capable of data transfer, and it is possible to initiate data transfers from the main unit or selected sub-units.