A plurality of control units capable of communicating with each other via a data communication network (TU) are disposed in distribution. One of the plurality of control units is set as an information management control unit (H1) having writable nonvolatile storing means. Upon activation with power supply thereof, the information management control unit (H1) executes a control management information distributing process for transmitting control management information stored in a memory (50) to storage object control units (H2-H6) via the communication network (TU). Upon activation with power supply thereto, each of the storage object control units (H2-H6) executes a control management information obtaining process for obtaining the control management information transmitted from the control management information control unit (H1).