Abstract: A plurality of AV appliances including a VTR and a HDD are connected to a network via a digital interface. The information with regard to the recorded information is recorded in a hard disk by a HDD in the information recording state to record the information in a tape by the VTR. Then, the information, which is recorded in the hard disk, is shared by respective AV appliances, which are connected to the network, so that it is possible to manage the recorded information in the tape.

Abstract: A self-device on a network is designed not to be unintentionally operated from a remote device. For this purpose, in a network including a self-device for performing processing corresponding to a received AV/C command and one or more remote devices for sending out AV/C commands (excluding commands containing only statuses), the self-device has mode 1 of giving a high priority to control on itself and mode 2 of accepting control from remote devices as well. Mode 1 or mode 2 is set by a user. In mode 1, the self-device rejects AV/C commands supplied from the remote devices.

Abstract: A signal output apparatus automatically determines which of a plurality of signals output from an apparatus is effective, and outputs the effective signal. For this purpose, the signal output apparatus comprises an output signal inquiring section configured to inquire an apparatus which outputs a plurality of kinds of signals about a kind of a signal output therefrom, an effective input signal determining section configured to determine which of a plurality of signals output from the apparatus is an effective input signal based on a result of inquiry by the output signal inquiring section, and a data outputting section configured to output data corresponding to the effective input signal based on a result of determination by the effective input signal determining section.