Abstract: A communications system connected via a bus capable of transferring combinations of control signals and AV signals as packets while providing an environment which is the same as an environment where connections are made using analog signal lines. A register decided by an address is taken to be a virtual plug for each item of equipment. The plug enable for the input plug is set to 1 and a synchronous communication packet for the AV signal from the channel set by the channel number is received. The plug enable for the output plug is set to one and the synchronous communication packet for the information signal is sent to the channel set by the channel number at a transmission speed designated by the DR (Data Rate) at the bandwidth expressed by “Bandwidth”.

Abstract: A communication system includes a communication control section which may receive bus use requests of both of a DV camera/recorder (50) which becomes an output machine on a serial bus (60D) and a DV deck (40) which becomes an input machine on the serial bus (60D), may check whether or not the serial bus (60D) which were requested to be used is in use, may open the serial bus (60D) to the DV camera/recorder (50) and the DV deck (40) which issued the use requests, may protect a connection between the DV camera/recorder (50) and the DV deck (40), may open a serial bus (60A) to an IRD receiver (10) and a mini disc (20) which issued use requests and which may protect a connection between the IRD receiver (10) and the mini disc (20).

Abstract: In a communication system, when data is read/written from/into a memory contained in a recording medium employed in one electronic appliance by another electronic appliance via a communication control bus such as the IEEE-1394 serial bus, the data read/write operations can be assured.

Abstract: In a system wherein a plurality of electronic apparatuses are connected by a communication control bus for communication between those electronic apparatuses, each of the electronic apparatuses selects an input apparatus by sending an inquiry to all other apparatuses in the system to determine whether they can output data, displays the apparatuses which respond that output is possible as candidate input apparatuses, and selects the input apparatus from among the candidate input apparatuses. For an electronic apparatus which can not output data, the reason for such inability to output data can be displayed at either the apparatus incapable of outputting data or the apparatus which is to select an input apparatus. Input apparatus selection can be also performed using a list made up of still images created from the image data supplied by candidate input apparatuses.

Abstract: A method of controlling communication for a communication system for connecting a plurality of electronic apparatuses through a communication control bus and allowing data communication between those electronic apparatuses wherein each of the electronic apparatuses performs connection control through the execution of a connection control command carried out by writing connection control information in a predetermined storage memory of its own or another electronic apparatus. The electronic apparatuses which attempt to write the connection control information transmit the write instructions to a predetermined storage memory. The storage memory which has received the write instructions, in turn executes only the earliest write instruction received and then transmits responses indicating whether the execution of the respective write instructions was successful or not.

Abstract: A bus connects a plurality of electronic devices. The address of a prescribed electronic device having a single connection-terminal is assigned based on parent/child considerations. The prescribed device having a single connection terminal is controlled by a designated device so that other devices on the bus cannot directly communicate with the prescribed device other than through the designated device. In one embodiment, the bus is a P1394 audio/visual serial bus, the prescribed device is a camcorder, and the designated device is a VCR.