Electronic device, electronic device using method, and electronic device system

Technical field

The The present invention relates to a method for an electronic Device system, for example an audio-visual apparatus (hereinafter referred to referred to as AV device ") for processing of visual information and auditory information, and a An information processing apparatus, the communication bus via a are connected together. In particular, the method relates on the prevention of the use of the electronic device system under overrun the transmission capacity of the communication bus.

State of the art

Of the serial bus according to IEEE 1394, for example, as a network system thought that the transmission of data by isochronous communication and the transmission of control signals by asynchronous communication between an AV device and an information processing apparatus allows the interconnected are. The serial bus according to IEEE 1394 is according to the standard "IEEE STD 1394-1995 "titled" IEEE STANDARD FOR A HIGH PERFORMANCE SERIAL BUS "standardized. As an example of the use of serial buses according to IEEE 1394 is disclosed in Japanese Patent Laid-Open No. H08-47058, a "method for selecting described input devices ", the only devices can show that are capable of an information signal as entry for available devices output in a system in which a plurality of electronic devices via the The communication bus are connected to each other.

It should also an "AV / C Digital Interface Command Set "in With regard to control signals to control the AV device for playback and Vorrich Recording of AV data using the serial bus after 1394 of the "1394 Trade Association "published been.

If However, in the method as the conventional method by 1394 more electronic devices hereinafter described isochronous communication simultaneously perform and also the available Width and number of channels exceeded the bus be able some of the electronic devices with which the devices communicate carry out want the bus because of the lack of available width and number of channels Do not use the bus.

It is a case possible that in a network in which, for example, a digital receiver IRD (hereinafter "IRD") and a device such as a digital video recorder D-VTR are connected to each other (hereinafter referred to as "D-VTR"), a reserved recording by the aforesaid network accomplished is. When the other electronic devices in the network are interconnected, the bus during the reserved recording time use and the bus width that the IRD wants to use is larger than the at the time in question is available bus width, can IRD not sure the bus width. Consequently, the reserved is Recording is not performed, because no data from the IRD is transmitted to the D-VTR.

Furthermore be at the input device-selection and the AV / C Digital Interface Command Set only a method of Choose of the input device to present Time and a transmission method for data and control signals for the current Time considered.

JP-08-023584 describes an electronic equipment control system having a Command processing part and a command processing execution part. The processing part transmits a Connection parameters to the execution part, and the execution part connects between tween the devices in accordance with this parameter ago.

The present invention to an electronic device Claim 1.. If in the electronic device system, in which the AV device and the information processing device via the Communications are interconnected, a reserved Play be performed and a reserved image recording, it requested the each reservation information for the connected devices. After that it judges on the basis of the data obtained from the inquired devices Response information, such as prior to the reservation of a communication resource accomplished can be; hence, a use of preventing that exceeds the transmission capacity of the communication bus, and reserving the communications resource is running.

Continue can according to the present invention, when a reservation or emergency communication impossible is, the cause will be displayed. Moreover, if the use of a Bus is prohibited because other devices have reserved the bus, the cause will be displayed.

Description of the Invention

The present invention relates to a system that, for example, an AV apparatus or an information processing apparatus via a Bus connects. to reliably To communicate, requested a device that in the Sys<?page 3?>tem can perform playback, the reservation information of the connected devices. To react to a response from the connected devices has the apparatus via an element that the availability assess the bus transmission capacity can enhance the capacity of not to exceed bus. Therefore, the device wants to use the bus, the transmission perform certain information.

By Judgment of whether the aforementioned use of the bus is available, the apparatus further comprises an element that indicates the cause to a video display device, if it is impossible is to use the bus. Therefore, the apparatus, in the case of a Playback reservation the appropriate setting for the reservation carry out.

Brief Description of Drawings

<figref idrefs="S26">1</figref> shows a block diagram of the electronic device system according to the preferred embodiment, the invention.

<figref idrefs="S26">2</figref> shows is a block diagram showing the configuration of the electronic device (IRD) according to the preferred embodiment the invention.

<figref idrefs="S27">3</figref> shows an example for securing the bus reservation according to the preferred embodiment the invention.

<figref idrefs="S28">4</figref> shows an example for ensuring the immediate communication to the preferred embodiment the invention.

<figref idrefs="S29">5</figref> shows a flow chart for the reservation method according to the preferred embodiment the invention.

<figref idrefs="S30">6</figref> shows an example for the structure of the transmission data according to the preferred embodiment the invention.

<figref idrefs="S30">7</figref> shows an example for the structure of the response data of the preferred embodiment the invention.

<figref idrefs="S31">8</figref> shows an example for the structure of the stored reservation data according to the preferred embodiment the invention.

<figref idrefs="S31">9</figref> shows an example for the structure of stored immediate communication data according to the preferred embodiment the invention.

<figref idrefs="S31">10</figref> shows an example for the structure of the preferred embodiment according to Businformationsdaten the invention.

<figref idrefs="S32">11</figref> shows an example for the Busreservierungsanzeige according to the preferred embodiment the invention.

<figref idrefs="S32">12</figref> shows an example for booking ad unavailability of the bus after preferred embodiment, the invention.

<figref idrefs="S33">13</figref> shows a flow chart for the immediate communication process according to the preferred embodiment the invention.

<figref idrefs="S34">14</figref> shows an example for emergency communication display according to the preferred embodiment the invention.

<figref idrefs="S34">15</figref> shows an example for emergency communication display unavailability of the bus after preferred embodiment, the invention.

<figref idrefs="S35">16</figref> shows a flow chart for the response method according to the preferred embodiment of the invention.

<figref idrefs="S36">17</figref> shows an example of the system with an indication of the priority according to the preferred embodiment the invention.

<figref idrefs="S37">18</figref> shows an example for the display of priority of the camera according to the preferred embodiment of the invention.

<figref idrefs="S37">19</figref> shows an example for the display of priority of the DVD player according to the preferred embodiment of the invention.

<figref idrefs="S38">20</figref> shows an example for the display of the reservation process to a personal computer according to the preferred embodiment the invention.

Best Modes the invention

below is the preferred embodiment of the present invention with reference to the drawings explained. Specifically ment of the preferred Ausfüh the present Invention, a method for the electronic devices such as an AV device and representing an information processing device, via a Bus are connected to each other, which is available for isochronous communication, For example, the IEEE 1394 bus, the reservation for the bus use and instant communication via the isochronous communication performed.

The isochronous communication in accordance with IEEE &lt;?page 4?&gt;1394 takes place at about 8 kHz. This is a secure data transmission mode in a transmission band. The data transmission by means of the packet transmission. The data packet has a header part and a data part, wherein, in the header part information such as the channel number and the size of the transmission data are included and the data part of the transmission data in 4 bytes contains. also is provided in IEEE 1394 asynchronous data transmission mode, is referred to as asynchronous communication. The asynchronous Communication is mainly for the transmission used commands.

<figref idrefs="S26">1</figref> shows a block diagram of a network system according to the preferred embodiment the invention. A television receiver TV <figref>100</figref>, A D-VTR <figref>101</figref> and a D-VTR <figref>102</figref> to the Recording and playing back AV data, a digital satellite broadcasting receiver IRD <figref>103</figref>. a digital video disc player DVD <figref>104</figref> (Hereinafter referred to as "DVD") for Reproduction of AV data, a digital video camera CAM <figref>105</figref> (hereinafter referred to as "CAM") for Recording and playing back AV data and a personal computer PC <figref>106</figref> (Hereinafter referred to as "PC") are on the IEEE 1394 bus cable <figref>108</figref> together connected. In the case of the isochronous communication to IEEE 1394 is one of the connected devices as Isochronous Manager <figref>107</figref> to Management of bus width and channels used. In this embodiment, is the D-VTR <figref>101</figref> as Isochronous Manager <figref>107</figref> shown, but it can also other devices such as the DVD <figref>104</figref> used as Isochronous Manager will.

As in <figref idrefs="S26">1</figref> shown, the devices compound as concatenated Bus structure or a tree structure or in the form of combinations it configured. Although in<figref idrefs="S26">1</figref> not shown, can also devices such as a hard disk drive, a printer, a scanner and an audio device be connected.

<figref idrefs="S26">2</figref> shows a block diagram showing the internal structure of the IRD, which one of the electronic devices, according to the preferred embodiment the invention. Numeral<figref>200</figref> denotes an internal Bus of the IRD. Numeral<figref>201</figref> denotes an input part for inputting setting data for the reservation. Numeral<figref>202</figref> denotes a Display part for displaying the necessary data in connection the setting for the reservation. Numeral<figref>203</figref> denotes a Central processor (CPU), the overall control and the method for the Bus reservation of IRD performs. Numeral <figref>204</figref> denotes a memory portion for Storing the reservation data, etc. Numeral <figref>205</figref> designated a communication part for the communication with the other devices. Numeral<figref>206</figref> designated a time control section for controlling the time. Numeral<figref>207</figref> designated a tuner part for receiving broadcast waves. Numeral<figref>208</figref> designated an image processing part for decoding received image data etc. Numeral <figref>209</figref> denotes a memory part, which is used when the CPU executes these procedures. Of the display part <figref>202</figref> is located not only on the housing of the IRD, but also on a remote control, and also the connected TV TV <figref>100</figref> can be used.

The following cases are as opportunities for Ensuring bus communication resource conceivable: <ul><li>(1) The case that the bus transmission capacity (hereinafter referred to as "bus width") for a time zone in the future a Busreservierungskommunikation ensures.</li><li>(2) The case that the bus width from the present time immediately for emergency communication is ensured.</li></ul>

During the Case (1) ensuring the bus width for the specified time zone shows may be the case (2) and ensuring the bus width without the specified time zone are considered from the current time.

If for example, the IRD <figref>103</figref> the bus width for the time zone wants to make sure in the future, as in <figref idrefs="S27">3</figref> shown, additionally in case (1), the following Cases are conceivable: <ul><li>(A) The case that available bus width with clearance opposite to the bus width for the time zone is present, which can be ensured for reservation should, like reference numerals <figref>300</figref> shown.</li><li>(B) The case where no available bus width without clearance opposite to the bus width for the time zone is present, which can be ensured for reservation should, like reference numerals <figref>301</figref> shown. If the For the IRD <figref>103</figref> a particular bus width for carrying out the wants to ensure immediate communication, as in <figref idrefs="S28">4</figref> shown are additionally in case (2), the following cases are conceivable:</li><li>(C) The case that available Bus width with room for the current Time and time zone in the future against the bus width for the time zone present, the aim is to ensure immediate, like reference numerals <figref>400</figref> shown.</li><li>(D) The case where available Bus width with room for the current Time, but no tolerance for the time zone in the future against the bus width for the time zone present, the aim is to ensure immediate, like reference numerals <figref>401</figref> shown.</li>&lt;?page 5?&gt;<li>(E) The case where no available bus width without at least room for the current time opposite to the bus width for the time zone is present, which is to ensure immediate, as at reference numeral <figref>402</figref> shown.</li></ul>

the Procedures for ensuring the communication resource for a time in the future for the Reservation in case (1) is in reference to the flowchart <figref idrefs="S29">5</figref>. the package structures in <figref idrefs="S30">6</figref> and <figref idrefs="S30">7</figref> and the Memory data formats in <figref idrefs="S31">8</figref>. <figref idrefs="S31">9</figref> and <figref idrefs="S31">10</figref> explained.

in the Hereinafter, the case (a) in <figref idrefs="S27">3</figref> explained.

In <figref idrefs="S29">5</figref> becomes in step <figref>500</figref> called the booking engine when a reservation starts. The start of the reservation process is from the ROM portion <figref>210</figref> saved Reservation processing program performed after the CPU <figref>203</figref> the Push booking Start button, for example, the input part <figref>201</figref> detected has. In step<figref>501</figref> asked it the bus use and the Reservation situation. The IRD<figref>103</figref> Calls for a response with the immediate communication information and the reservation information from Isochronous Manager <figref>107</figref> and connected to the bus equipment at. He produced as in<figref idrefs="S30">6</figref> shown, a package that includes a function code corresponding to the requested includes response and transmits it as Request information on the communication part <figref>205</figref> to all stations on the bus Devices.

In step <figref>502</figref> are the response data with the immediate communication information and the reservation information for the bus, which together form the representing bus usage, receive. The response data are connected to the communication part <figref>205</figref> received and the Memory part <figref>209</figref> stored. The communication part<figref>205</figref> receives the For the present available Bus Width <figref>100</figref> and channel information from the isochronous manager <figref>107</figref>. as in <figref idrefs="S31">10</figref> shown, and the response data nikationsinformationen with Sofortkommu and Reservation Information of the connected devices, like reference numerals <figref>702</figref> in <figref idrefs="S30">7</figref> shown. In this case, for example, the content states of the answer data from the Isochronous Manager <figref>107</figref>That currently 80 MBPS available on the bus. also to the content of the response from the D-VTR <figref>101</figref> indicate that Reserved 30 MBPS of the bus width on 14 December 18:00 to 20:00 are.

In step <figref>503</figref> a user inputs information using as requested data for the bus (hereinafter referred to as "reservation request data") in connection with the bus usage for example a desired time zone for the Reservation. The data with the input part<figref>201</figref> entered and in memory <figref>209</figref> stored. As with numerals<figref>1101</figref> in <figref idrefs="S32">11</figref> shown, gives the user, for example, the reservation request information, such as about a bus width of 20 Mbps (megabits per second) from 19:00 to 21:00 on December 14 in the IRD <figref>103</figref> on.

In step <figref>504</figref> it assesses the possibility of reservation. The in memory part <figref>209</figref> stored reservation request data, received in response immediate communication information and the obtained in response reservation information are compared and evaluated. The judgment is of the CPU<figref>203</figref> performed. The CPU <figref>203</figref> uses a scanning method for testing whether an overlap present with an already reserved time zone. It is possible that Bus width of the already existing reservation of the bus width deduct, which is the maximum available in the overlapping time zone and perform the evaluation with a known method. It overlaps with time zone in which the D-VTR <figref>101</figref> within a time zone is reserved, the IRD <figref>103</figref> would like to reserve, and the period 19:00 to 20:00. But even if for instant communication considered seized 20 MBPS be, is the bus width that is available in a time zone with which the overlaps reservation, 50 MBPS. Therefore, it notes that the bus width of 20 MBPS, the IRD <figref>103</figref> would like to book, can be reserved, and proceeds to step <figref>505</figref>,

In step <figref>505</figref> be the reservation request data as a bus usage stored; then it continues with step<figref>506</figref>, The use reservation information be in the storage part <figref>204</figref> stored. <figref idrefs="S31">8</figref> shows a data structure stored. A reservation time zone part<figref>800</figref> contains information about the reserved time zone the reserved device. A bus-reservation portion <figref>801</figref> contains information about the Reserved bus width. A channel number reservation part<figref>802</figref> contains information about the reserved channel number. In step<figref>506</figref> ends the reservation process.

in the The case (b) will be explained. The use situation is the same as described in the above- Case 1).

In step <figref>503</figref> a user inputs the desired reservation data for example the desired time zone for the Reservation. The data with the input part<figref>201</figref> entered and in memory <figref>209</figref> stored. If the IRD<figref>103</figref> a Reservations performs, the more than 70 MBPS (megabits per second) in the time zone 19:00 to 21:00 &lt;?page 6?&gt;December 14, requires, In this case, however, the bus width that is available in the time zone, low.

at assessing the possibility for the time zone in step <figref>504</figref> the process goes to finding that reservation not possible is, go to Step <figref>507</figref>,

In step <figref>507</figref> is the reason why the reservation not possible is, as indicated at reference numeral <figref>1201</figref> in <figref idrefs="S32">12</figref>; then it continues with step <figref>508</figref>,

In step <figref>508</figref> it is decided whether the reservation again is attempted or completed. A line of text that indicates whether the reservation retried, or is stopped, for example, on the display part <figref>202</figref> displayed, whereupon the user selects the desired The method with the input part <figref>201</figref> enters. The input Information from the CPU <figref>203</figref> judges that decides if they step <figref>503</figref> or step <figref>506</figref> continues. As already mentioned, calls the device, trying to make the reservation, the reservation information of equipment connected to the bus devices to. After the judgment the possibility the reservation based on the response information and Information from the bus manager performed. Although the reservation can not be performed, the reservation for the same is Time zone for other devices is reserved, canceled by judgment of the user, and the reservations the IRD <figref>103</figref> may be given priority.

As next the process is to ensure communications resource from the current Time in the immediate communication in case (2) on the basis of the flow chart in <figref idrefs="S33">13</figref>, The packet structures in <figref idrefs="S30">6</figref> and <figref idrefs="S30">7</figref> and the memory data formats in <figref idrefs="S31">8</figref>. <figref idrefs="S31">9</figref> and <figref idrefs="S31">10</figref> explained.

in the The case (c) will be explained.

step <figref>1300</figref> becomes Called when ensuring the immediate communication started is. Starting the instant communication of the in ROM portion<figref>210</figref> saved Instant communication processing program carried out after the CPU <figref>203</figref> pressing an emergency communication start button, for example, the input part <figref>201</figref> detected has. In step<figref>1301</figref> Calls the IRD <figref>103</figref> a Answer with the immediate communication information and the reservation information from Isochronous Manager <figref>107</figref> and connected to the bus equipment at. Thereafter it generates, as shown in<figref idrefs="S30">6</figref> shown, a packet having a function code, and it transmits through the communication portion <figref>205</figref> at all devices connected to the bus.

In step <figref>1302</figref> are the response data with the immediate communication information and the reservation Informa tion received. You are in communication part<figref>205</figref> receive, and these data are in the memory part <figref>209</figref> stored. The communication part <figref>205</figref> receives, for example, the currently available bus width <figref>100</figref> and Channel information from the isochronous manager <figref>107</figref>, as in <figref idrefs="S31">10</figref> shown, and the answer to the immediate communication information and the Reservation information of the connected devices. In this case means, for example, the content of the response data from the Isochronous Manager <figref>107</figref>That currently 80 MBPS available on the bus. also to the content of the response from the D-VTR <figref>101</figref> indicate that Reserved 30 MBPS of the bus width on 14 December 18:00 to 20:00 are. About that addition to the content of the response from the D-VTR <figref>104</figref> specify, that 20 MBPS of the bus width for emergency communications are used.

In step <figref>1303</figref> is the bus width that is needed for emergency communications, as immediate communication data, that is, as Buswunschverwendungsinformationen, entered and the RAM memory part <figref>209</figref> stored. Such as at reference numeral <figref>1401</figref> in <figref idrefs="S34">14</figref> shown, 20 MBPS than the bus width is stored, for urgent communications necessary is.

In step <figref>1304</figref> the possibility the instant communication assessed. The response data and the instant communication data are compared and evaluated. The judgment is of the CPU<figref>203</figref> performed. The CPU <figref>203</figref> uses a scanning method for testing whether an overlap present with an already reserved time zone. It is possible that Bus width of the already existing reservation of the bus width deduct, which is the maximum available in the overlapping time zone, and perform the judgment with a known method. The currently is usable bus width 80 MBPS, and the D-VTR is for the period 19:00 to 20:00 in the time zone in the future reserved. Because as available Bus width remains 50 MBPS in the time zone, even if for urgent communications seized 20 MBPS be deducted, it is determined that 20 MBPS at bus width for the instant communication of the IRD <figref>103</figref> be ensured can; then it continues with step <figref>1305</figref>, In step<figref>1305</figref> will the immediate communication information in the storage part <figref>204</figref> stored, and then it goes on to Step <figref>1306</figref>, <figref idrefs="S31">9</figref> shows a data structure stored. An emergency communications Busbreitenteil<figref>900</figref> contains information about the Bus width used. An emergency communication channel part<figref>901</figref> contains information about the reserved channel number. In step<figref>1306</figref> age of instant communication process. The Sofortkommunikationsverarbeitungspro&lt;?page 7?&gt;program, which from the ROM part <figref>210</figref> called was, is terminated.

in the The case (d) will be explained. The use situation of the devices is the same as the above case (c).

In step <figref>1303</figref> are, for example, 60 MBPS as for urgent communications necessary bus width in RAM memory <figref>209</figref> stored. In this case in step <figref>1304</figref>Because the bus width in the reserved Timezone the D-VTR <figref>101</figref> beat is detected that the bus width for instant communication can not be ensured; therefore continues with step<figref>1307</figref>, The reason why the instant communication is not possible, is, for example, as at reference numeral <figref>1501</figref> in <figref idrefs="S34">15</figref> displayed; then it continues with step <figref>1308</figref>, In step<figref>1308</figref> becomes decided whether the setting of the immediate communication retried or is terminated.

in the Case (d) if the instant communication than the reserved communication changed is, that is until the start time of the D-VTR <figref>101</figref>She can 19:00 be ensured.

in the The case (e) will be explained. The use situation of the devices is the same as the above case (c).

In step <figref>1303</figref> it is assumed that the bus width, the more 90 MBPS is, than that for the Instant communication necessary Bus width in the RAM memory part <figref>209</figref> is stored. In this case, in step <figref>1304</figref> noticed, that the bus width for the instant communication can not be ensured because the Bus Width currently already is scarce; then it continues with step<figref>1307</figref>,

In step <figref>1307</figref> is the reason why the instant communication not possible is displayed; then it continues with step<figref>1308</figref>, In step <figref>1308</figref> it is decided whether the setting of the Instant communication is attempted or completed again.

As already mentioned, calls the device, trying to make the reservation, the immediate communication information and the reservation information of the devices connected to the bus equipment at. Thereafter, the assessment of the feasibility of the reservation based on the answer information and the Information the bus manager performed. Although the instant communication is not possible, the reservation will for the same Time zone for other devices is reserved, canceled by judgment of the user, and reserving for the IRD <figref>103</figref> may be given priority.

at this embodiment the possibility the reservation in step <figref>504</figref> assessed but a limitation the bandwidth and channel count is conceivable to the instant communication to carry easily in the reserved time zone. For example, if the Bandwidth and channel number are set so that only 80% of Maximum value of the respective bus width and number of channels are possible, to make a reservation with the ROM portion <figref>210</figref> saved make reservation processing program, can at least 20% of the maximum value of the respective bus width and number of channels for instant communication be USAGE det, even if time is a reserved time zone.

In addition, the system, the procedure for View the event that the reservation for a device is released when the reservation is not possible is. To ensure the almost expectant bus width, are in the CPU <figref>203</figref> in the part of the reservation processing in step <figref>504</figref> several patterns calculated that reservations other devices must be lifted and by displaying the result on the display part <figref>202</figref> activated and selected by the user.

at the above embodiment, is the embodiment declared been that all devices respond to the request for the bus usage, but carried out with the system may be, only the reserving device, to communicate that, communicated immediately. In<figref idrefs="S35">16</figref> is an example for a method for processing the device shown, at this time responds. In this figure, a case is explained that other electronic Devices, the immediate communication information to the bus and a request packet with the response of the Reservation Information the IRD <figref>103</figref> transfer.

In step <figref>1600</figref> This begins when the response request packet Will be received. The CPU<figref>203</figref> checking whether the communication part <figref>205</figref> the Package with the function code for the response request received, one in the ROM portion <figref>210</figref> saved Response processing program is started. In step<figref>1601</figref> becomes the function code is decoded. The CPU <figref>203</figref> sees the function code table in ROM <figref>210</figref> after, and the function code is evaluated. In step<figref>1602</figref>. if the function code is a response request concerning the is using or reservation situation, it continues with step <figref>1603</figref>, If it is a different function code, it continues with step <figref>1606</figref>,

In step <figref>1603</figref> the answer processing is performed. The CPU <figref>203</figref> sees in the storage part <figref>204</figref> according to check, if the bus is reserved or of the own device for emergency communications is used. Lying Reservation Information&lt;?page 8?&gt;and immediate communication information before, this information will be in the work RAM <figref>210</figref> expanded and the response format adapted. If no reservation information and immediate communication information before it moves to step <figref>1605</figref>, In step <figref>1604</figref> transmitted a response packet. The response to the format custom response packet is the communication part <figref>205</figref> transfer. The program ends in step <figref>1605</figref>, The response processing program the ROM portion <figref>210</figref> will be terminated. In step<figref>1606</figref> leads the CPU <figref>203</figref> the function code corresponding processing by and proceeds to step <figref>1605</figref>,

at this method can Only the devices respond, perform the reservation and instant communication. Also sends for example, the IRD <figref>103</figref> the time zone information should be reserved to each device, but only some of the devices while the same time zone are reserved and use the bus at present, can respond. In this case, the information for the time that the IRD be <figref>103</figref> want to reserve, in Function code <figref>701</figref> inserted. Next judged as the D-VTR <figref>101</figref> in step <figref>1304</figref> the reservation response processing program D-VTR <figref>101</figref>Whether a reservation during the time present or the bus currently is used, and may determine whether it sends the answer packet.

In addition, a priority for the Bus use and reservations are set.

This is based on <figref idrefs="S36">17</figref>. <figref idrefs="S37">18</figref> and <figref idrefs="S37">19</figref> explained. Here is, for example, a video of a DVD player <figref>1704</figref> to a PC <figref>1706</figref> transfer and dubbing a D-VTR <figref>1702</figref> from a camera <figref>1705</figref> performed. there is a case conceivable that urgent information from a broadcasting station or a network via the IRD <figref>1703</figref> and the PC <figref>1706</figref> received and on TV <figref>1700</figref> to be displayed. If no margin is given when the bus width, it is possible, that the urgent information can not be displayed. there , as at reference numeral <figref>1801</figref> in <figref idrefs="S37">18</figref> shown, the priority the bus use for a video recording from the camera <figref>1705</figref> to the D-VTR <figref>1702</figref> is set to "Priority". In addition, the priority the bus use for a reproduction from the DVD player <figref>1704</figref> to the PC <figref>1706</figref> "Normal" is set to as at reference numeral <figref>1901</figref> in <figref idrefs="S37">19</figref> shown. It should also the priority the bus use for the urgent information from the IRD <figref>1703</figref> to the TV <figref>1700</figref> set to "highest priority". In this case, even if no available bus width is present, the bus use for playback from the DVD player <figref>1704</figref> with "normal" priority to the PC <figref>1706</figref> stopped, and the bus width for the urgent information necessary is, it can be ensured, so that the information on the TV <figref>1700</figref> can be displayed. When a PC<figref>1706</figref> With a function to control other devices is connected, may, also when the normal reservation operation is performed by each device, reservation and collectively with the PC <figref>1706</figref> done. In <figref idrefs="S38">20</figref> is an example of the operation screen on the personal computer shown. The screen<figref>2000</figref> is the Monitor of a personal computer. A Busressource that a Reservation time and a date is ensured for the bus, is in a display window <figref>2002</figref> displayed. In the Anzeigefe nster the operation screen is displayed. Thereafter, the reservation will be for a Program and time set. The operating window for the D-VTR is in a display window <figref>2003</figref> displayed. One mode of operation for the Video recorder.

Continue A case will be assumed that a device on the IEEE 1394 network is connected or disconnected and a bus reset in <figref idrefs="S29">5</figref> takes place. In this case, if the IRD <figref>103</figref> a reservation for Capturing video on the D-VTR <figref>101</figref> from IRD <figref>103</figref> Has and the IRD is disconnected from the network as a whole, takes the opportunity the booking of bus width on the network. A device that the Bus used or makes a reservation, calling step <figref>500</figref> on, and in step <figref>501</figref> it queries all devices connected to the bus are reissues. Because each device its use or reservation information in the storage part <figref>204</figref> stores, gives each device in step <figref>503</figref> automatically the information, whereupon in step <figref>504</figref> the use or reservation will be tested. If a problem occurs, it may in the state before the bus reset to return. Can it but for some reason not to return to this state, shows it in step <figref>507</figref> the reason for this to.

Continue in the embodiment in step <figref>507</figref> a warning as a means to display the reason why the reservation is not possible appears. The warning However, can not only be displayed on the TV monitor, but on a liquid crystal display a remote control, on the control panel on the casing of an electronic device or on a display device. can place the warning a warning, an audio signal or music output to an audio device will. additionally is means conceivable, with which a user based warning can recognize blinking of a light emitting diode.

Industrial applicability

Because The present invention as vorste&lt;?page 9?&gt;mentioned basis, preventing a reservation may, which exceeds the bus transmission capacity can a reliable Communication may be performed, For example, at the time of reservation for recording. In addition, the user, if the reservation is not possible, a corresponding operation run, because the cause is shown why the reservation is not possible.

Continue there is a case where, when a device tries to instant communication to start after a seizure of the bus, the device is concerned, the bus at the time for the other device a reservation in the future, has not be able to use. If a step that starts the instant communications, or a previous Level communication can not perform, are the present Invention provides a warning to the user to one of the displayed Warning appropriate action to take.