Patent ID: 7181554

Claim:
A controller device to be connected to an IEEE 1394 serial bus network via an IEEE 1394 serial bus, comprising: an IEEE 1394 interface (hereafter referred to as “interface”) to send and receive data, such as commands and contents, to and from each target device on the IEEE 1394 serial bus network; a memory to store various data including function information of the each target device sent from the each target device via the interface; and a microprocessor to control the each target device in accordance with the function information of the each target device stored in the memory, wherein the memory stores a current function information list which is a list of function information of the each target device currently connected to the IEEE 1394 serial bus network, and which is made by the microprocessor in accordance with GUID and function information of the each target device sent from the each target device, wherein when the microprocessor gets GUID of the each target device from the each target device via the interface after bus reset, the microprocessor searches for a record of the target device corresponding to the gotten GUID from records in the current function information list, and wherein if the microprocessor finds a record of such target device corresponding to the gotten GUID as a result of the search, the microprocessor allows the record of such target device to remain in the current function information list.