JP2005295522A - Data transferring device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish only a certain number of bands corresponding to the number of transmission plugs which are each really set by connection to a reception plug by combining a decreasing process and an increasing process of a sequence, on a bus capable of performing an isochronous transfer. <P>SOLUTION: A data transferring device to be connected to a network which is composed of a plurality of data transferring devices and capable of performing the isochronous transfer comprises disconnecting means for disconnecting a connection between a transmission plug of a transmission node connected to the network which is capable of performing the isochronous transfer and a reception plug of a reception node, requesting means for requesting a transmission sequence to be optimized relating to the transmission node, receiving means for receiving information relating to the transmission plug newly assigned to the transmission sequence which is used by the transmission node disconnected the connection from the transmission node as a response to an optimization request, and setting means for newly setting a connection between the newly assigned transmission plug and a reception plug disconnected the connection. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a data transfer apparatus, and more particularly to a data transfer apparatus connected to a communication network capable of isochronous transfer such as an IEEE 1394 network.

The IEEE 1394 standard is known as a serial bus interface standard. In a communication network conforming to the IEEE 1394 standard (hereinafter simply referred to as IEEE 1394 network), a maximum of 63 devices conforming to the IEEE 1394 standard (hereinafter simply referred to as IEEE 1394 equipment) may be connected to one bus (local bus). it can.

In general, a controller that optimizes the usage efficiency of the local bus and other nodes are connected to one bus by controlling parameters relating to the configuration of the bus. As other nodes, for example, an audio device such as an AUDIO device that can output an audio (voice) signal, a MIDI device that outputs a MIDI signal, or the like, a predetermined number of data (for example, audio channels for 8 channels) A streamer and a MIDI stream for one cable) are sent on the bus as one isochronous stream (one isochronous packet transfer per isochronous period), and an isochronous stream sent by the talker A listener (receiving node) for receiving is connected. (For example, refer nonpatent literature 1).
"Consumeraudio / video equipment-Digital interface-Part 6: Audio and music datatransmission protocol", International ElectrotechnicalCommission, July 12, 2002

  FIG. 9 is a conceptual diagram showing a technique for establishing a connection between a transmission plug and a reception plug in a conventional IEEE 1394 device.

  In the talker which is a transmission node, eight transmission plugs [0-7] are set, and eight transmission FIFOs are prepared according to the number of transmission plugs. The path of the transmission FIFO [0-7] corresponding to the transmission plug [0-7] is fixed and cannot be changed.

  Similarly, eight reception plugs [0-7] are set in the listener which is a reception node, and eight reception FIFOs are prepared according to the number of reception plugs. The path of the reception FIFO [0-7] corresponding to the reception plug [0-7] is fixed and cannot be changed.

  In the conventional IEEE 1394 equipment, the number of sequences of the data stream transmitted from the transmission node is fixed, and the number of sequences cannot be increased or decreased dynamically. In the example shown in FIG. 9, when there are eight sequences Seq [0-7] transmitted from the transmission node, it is necessary to always ensure a band corresponding to eight sequences on the IEEE 1394 bus. There is.

  For example, as shown in FIG. 9, when a connection is established between a transmission plug [4, 5] and a reception plug [0, 1], the number of sequences cannot be increased or decreased dynamically. Even if only one sequence is received, the transmitting node needs to transmit all eight sequences.

  That is, the conventional IEEE 1394 equipment occupies the band wastefully by continuously sending out the data stream without the receiver. For example, when there are receivers in only the 7th and 8th channels among the 8 audio channels transmitted by the sender, the 1st to 6th channels with no receivers consume useless bandwidth. The same applies to a network having an isochronous transfer function other than the IEEE 1394 network, and the number of sequences transmitted in an isochronous stream cannot be dynamically changed.

  An object of the present invention is to provide a data transfer apparatus that can effectively use resources (bandwidth) on a bus capable of isochronous transfer.

  According to one aspect of the present invention, a data transfer device connected to an isochronous transfer-capable network including a plurality of data transfer devices includes a transmission plug and a reception node of a transmission node connected to the isochronous transfer-capable network. A disconnect means for disconnecting the connection with the reception plug, a request means for requesting the transmission node to optimize the transmission sequence, and a transmission sequence used by the transmission node for which the connection has been disconnected are newly added. A new connection is established between the receiving means for receiving information on the allocated transmission plug from the transmission node as a response to the optimization request, and the newly allocated transmission plug and the reception plug that has disconnected the connection. Setting means for setting.

  According to another aspect of the present invention, a data transfer device connected to an isochronous transfer-capable network composed of a plurality of data transfer devices can transmit a transmission sequence from a control node connected to the isochronous transfer-capable network. Receiving means for receiving an optimization request; duplicating means for copying data sent by a transmission plug assigned to a first transmission sequence at the end of a data stream in accordance with the optimization request; and the isochronous Sending means for sending the duplicated data in duplicate using a second transmission sequence in which no connection is established with the receiving plug of the receiving node connected to the transferable network, and the first Stopping means for stopping data transmission according to the transmission sequence of the first transmission sequence, and the first transmission sequence And a releasing means for releasing a band that has been used in the isochronous transfer can be on the bus.

  According to the present invention, by dynamically increasing the number of transmission sequences according to the number of established connections, only the necessary bandwidth can be used, and resources on the bus that can be transferred isochronously can be used effectively. can do.

  In addition, according to the present invention, by dynamically reducing the number of transmission sequences according to the number of connections set, only the necessary bandwidth can be used, and resources on the bus that can be transferred isochronously can be effectively used. It can be used for.

  Further, according to the present invention, by combining the sequence reduction process and the increase process, it is possible to perform isochronous transfer only for the number of sequences corresponding to the number of transmission plugs that are actually set with the connection with the reception plug. Since it can be secured on the bus, it is possible to eliminate a useless bandwidth for a sequence, and it is possible to effectively utilize resources of a bus that can be transferred isochronously.

  FIG. 1 is a bus configuration diagram of a network 100 according to an embodiment of the present invention.

  The network 100 is configured, for example, by connecting the controller 1C, the talker 1T, and the listener 1R with an IEEE 1394 cable so that they can communicate with each other. The network 100 may be any network that can perform isochronous transfer. For example, there are an IEEE 1394 network, a network using Universal Serial Bus (USB), and a network using ConbraNet (registered trademark). Here, "isochronous transfer" is a data transfer method that ensures and guarantees transfer data capacity (bandwidth) per fixed time by preferentially flowing isochronous packets to the bus at a predetermined isochronous cycle. For example, by interrupting the bus at a predetermined isochronous period and stopping other communications, and preferentially flowing isochronous packets to the bus, even if other devices use the network or bus and the traffic is high, A method is employed in which a transfer capacity (bandwidth) per fixed time (one frame) is secured and guaranteed. The isochronous transfer method guarantees the data capacity per fixed time, but does not guarantee the transfer data itself. If an error or the like occurs, the data is not used and is discarded.

  The controller (control node) 1C is composed of, for example, a personal computer and can control parameters relating to the bus configuration.

  The talker 1T is, for example, a predetermined number of data (for example, an audio stream for 8 channels and an AUDIO device such as an electronic musical instrument that can output an audio (voice) signal), a MIDI device that outputs a MIDI signal, and the like. This is a transmission node that transmits a MIDI stream for one cable) onto the bus as one isochronous stream. The listener 1R is a receiving node that receives the isochronous stream transmitted from the talker 1T.

  Here, “stream” refers to “data flow” and refers to simultaneous reproduction while receiving data such as video and audio in a communication network. As a result, the data can be reproduced without waiting until all data is received, and isochronous (isochronous) is maintained.

  In the network capable of isochronous transfer assumed in the present invention, one isochronous packet includes a plurality of sequences of data, and each device transmits one isochronous packet for each isochronous period. A plurality of sequences can be transmitted by sending them to the bus. Here, the “sequence” is a unit of data flow with a guaranteed bandwidth. When an audio stream or a MIDI stream is to be transmitted, the audio stream or the MIDI stream is included in any sequence. To send. A plurality of sequences included in one isochronous stream are assigned sequence numbers for specifying each sequence.

  In the drawings of the following embodiments, a network conforming to the IEEE 1394 standard (IEEE 1394 network) will be described as an example.

  FIG. 2 is a block diagram showing a hardware configuration of the communication node 1 (controller 1C, talker 1T, listener 1R) according to the embodiment of the present invention.

  A RAM 7, ROM 8, CPU 9, external storage device 15, detection circuit 11, display circuit 13, sound source circuit 18, effect circuit 19, and communication interface 21 are connected to the bus 6 of the data transfer device 1.

  The user can make various settings using the operation element 12 connected to the detection circuit 11. The operation element 12 may be any one that can output a signal corresponding to a user input, such as a mouse, a character input keyboard, a joystick, a rotary encoder, a switch, or a jog shuttle.

  The operation element 12 may be a soft switch or the like displayed on the display 14 operated using another operation element such as a mouse.

  The display circuit 13 is connected to the display 14 and can display various information on the display 14.

  The external storage device 15 includes an interface for an external storage device, and is connected to the bus 6 via the interface. The external storage device 15 includes, for example, a floppy (registered trademark) disk drive (FDD), a hard disk drive (HDD), a magneto-optical disk (MO) drive, a CD-ROM (compact disk-read only memory) drive, and a DVD (Digital Versatile Disc). ) Drive, semiconductor memory, etc.

  The external storage device 15 can store various parameters, various data, a program for realizing the present embodiment, automatic performance data, and the like.

  The RAM 7 has a working area for the CPU 5 that stores flags, registers or buffers, various parameters, and the like. The ROM 8 can store various parameters and control programs, or a program for realizing the present embodiment. The CPU 9 performs calculation or control according to a control program or the like stored in the ROM 8 or the external storage device 15.

  The timer 10 is connected to the CPU 9 and supplies a basic clock signal, interrupt processing timing, and the like to the CPU 9.

  The tone generator circuit 18 generates a musical sound signal in accordance with audio data and a performance signal such as a MIDI signal, and supplies it to the sound system 20 via the effect circuit 19.

  The effect circuit 19 gives various effects to the digital musical tone signal supplied from the sound source circuit 18. The sound system 20 includes a D / A converter and a speaker, converts a supplied digital musical tone signal into an analog format, and generates a sound.

  The communication interface 21 is an interface conforming to the IEEE 1394 standard. The communication interface 21 may further include an interface connectable to the communication network 3 such as a LAN (local area network), the Internet, or a telephone line. In that case, the server computer or the like is connected via the communication network 3, and a control program, a program for realizing the present embodiment, or the like is downloaded from the server computer to the external storage device 15 such as the HDD or the RAM 7 or the like. be able to.

  The communication interface 21 may further include a MIDI interface to which a MIDI device can be connected, a USB interface to which a USB device can be connected, and the like.

  When the communication node 1 is used as the talker 1T or the listener 1R, it may be in the form of an acoustic device such as an amplifier, a speaker, a mixer, or an electronic musical instrument. In that case, a function necessary for each device is executed. It suffices to provide only the members necessary to do this. For example, the display circuit 13 and the display 14 can be omitted as appropriate.

  FIG. 3 is a conceptual diagram for explaining a first example of the sequence reduction process according to the present embodiment.

  FIG. 3A is a conceptual diagram showing an initial state of sequence assignment before the sequence reduction process according to the present embodiment. In the initial state, a connection is set between plugs having the same number between the transmission plugs (Tx0 to 3) and the reception plugs (Rx0 to 3). The number of sequences at this time is “4”. That is, the talker 1T secures a band for four sequences on the IEEE 1394 bus.

  Here, when the connection from the transmission plug [Tx0] to the reception plug [Rx0] is disconnected, the state shown in FIG. That is, the transmission plug [Tx0] transmits a data stream via the transmission FIFO [0], and the band for the sequence Seq [0] is used, but the reception plug [Rx0] Is not received. Since the conventional device cannot dynamically decrease the number of sequences, the bandwidth on the IEEE 1394 bus remains the same as the state shown in FIG. Bands corresponding to one sequence are wasted.

  Therefore, in this embodiment, sequence optimization processing is performed after the connection is disconnected. First, as shown in FIG. 3C, the data of the transmission plug (Tx3) assigned to the last sequence Seq [3] is duplicated and the sequence Seq [0] is transmitted via the transmission FIFO [0]. 0]. At this time, the data of the transmission plug (Tx3) is transmitted on the bus in duplicate in the sequences Seq [0] and Seq [3].

  Next, as shown in FIG. 3D, the sequence received by the reception plug (Rx3) is changed from the sequence Seq [3] to Seq [0]. In this way, the data of the transmission plug (Tx3) is sent in duplicate to the sequences Seq [0] and Seq [3], and the data received by changing the sequence received by the reception plug (Rx3) in the meantime Transmission and reception can be performed without interruption.

  Finally, as shown in FIG. 3E, data transmission via the transmission FIFO [3] is stopped, the sequence Seq [3] is eliminated, and the number of sequences is decreased from “4” to “3”. Thereafter, the available bandwidth on the IEEE 1394 bus is increased by releasing the bandwidth reserved by the sequence Seq [3].

  As described above, when a connection is disconnected, the sequences that are being used are changed from Seq [0] to Seq [while maintaining the connections of the sequences Seq [1] and Seq [2] according to the disconnection of the connection. 3] is dynamically reduced from Seq [0] to Seq [2], and the bandwidth on the IEEE1394 bus corresponding to the reduced sequence is released, so that the resources of the IEEE1394 bus can be used effectively.

  FIG. 4 is a conceptual diagram for explaining a second example of the sequence reduction process according to the present embodiment. In this example, a case where data reception of two reception plugs is stopped will be described. In the initial state, a connection is established between plugs having the same number between the transmission plugs (Tx0 to 7) and the reception plugs (Rx0 to 7). The number of sequences at this time is “8”. That is, the talker 1T reserves a band for eight sequences on the IEEE 1394 bus. Here, as shown in FIG. 4A, the connection from the transmission plug [Tx4] to the reception plug [Rx4] and the transmission plug [Tx5] to the reception plug [Rx5] is disconnected.

  First, the data of the transmission plug (Tx7) assigned to the last sequence is duplicated and sent over the bus through the transmission FIFO [4] using the sequence Seq [4]. Thereafter, the sequence received by the reception plug (Rx7) is changed from the sequence Seq [7] to Seq [4]. Next, data transmission via the transmission FIFO [7] is stopped, the sequence Seq [7] is eliminated, and the number of sequences is decreased from “8” to “7”. Thereafter, the bandwidth reserved by the sequence Seq [7] is released. At this point, the state shown in FIG. 4B is obtained, and the total number of sequences is “7”.

  Next, the data of the transmission plug (Tx6) assigned to the last sequence in the state of FIG. 4B is duplicated, and the sequence Seq [5] is transmitted via the transmission FIFO [5]. The sequence is duplicated and transmitted on the bus, and then the sequence received by the reception plug (Rx6) is changed from the sequence Seq [6] to Seq [5]. Next, transmission of data via the transmission FIFO [6] is stopped, the sequence Seq [6] is eliminated, and the number of sequences is decreased from “7” to “6”. Thereafter, the bandwidth reserved by the sequence Seq [6] is released.

  With the processing as described above, the state shown in FIG. 4C is obtained, and the bandwidth for the two sequences used by the sequences Seq [6] and Seq [7] is released, so that the IEEE1394 bus is used. Resources can be used effectively.

  FIG. 5 is a flowchart showing the sequence reduction process according to this embodiment. Note that the dotted arrows in the figure indicate the flow of commands. This sequence reduction process starts when there is an instruction to disconnect the connection from the designated transmission plug (TxA) of the talker 1T to the reception plug of the listener 1R.

  In step SA1, the processing in the controller 1C is started, and in step SA2, the connection from the designated transmission plug (TxA) of the talker 1T to the reception plug of the listener 1R is disconnected.

  In step SA3, the number of connections set in the transmission plug (TxA) of the designated talker 1T (the number of reception plugs (Rx) receiving the isochronous stream transmitted from the transmission plug (TxA)) is set. Then, it is determined whether or not the connection disconnection process at step SA2 has become zero. When the number of connections becomes 0, that is, when there is no reception plug (Rx) receiving the isochronous stream transmitted from the transmission plug (TxA), the process proceeds to step SA4 indicated by a YES arrow. If the number of connections is not 0, that is, if there is a reception plug that is connected to the transmission plug (TxA) in addition to the reception plug that has been disconnected in step SA2, step SA7 indicated by an arrow of NO is entered. Then, the process in the controller 1C is finished. Here, when the process is terminated according to the arrow of NO, the process in the talker 1T is not performed.

  In step SA4, the designated talker 1T is requested to optimize the transmission sequence. After that, when the ID of the transmission plug (TxB) whose sequence to be transmitted from the talker 1T is to be changed and the ID of the new sequence Seq [i] are received in step SA10 described later, the transmission plug (TxB) is identified in step SA5. The sequence to be received by the reception plug of the listener 1R for which the connection is set is changed to Seq [i].

  In step SA6, the completion of changing the sequence of all the receiving plugs for which the connection is established with the transmission plug (TxB) is confirmed, and when the confirmation is completed, the talker 1T is notified of the completion of setting. Then, it progresses to step SA7 and complete | finishes the process in the controller 1C.

  In step SA8, processing in the talker 1T is started. After that, after receiving the optimization request for the transmission sequence sent from the controller 1C in step SA3, in step SA9, the sequence Seq [n−1] at the end of the data stream (n is the total number of sequences at this time). Is duplicated in the sequence Seq [i] used by the transmission plug (TxA) that duplicates the data of the transmission plug (TxB) transmitted in step S2 and disconnects the connection to the reception plug of the listener 1R in step SA2. And send it out.

  In step SA10, the controller 1C is notified of the ID of the transmission plug (TxB) whose sequence is about to be changed and the ID of the new sequence Seq [i].

  In step SA11, it is determined whether or not the setting completion notification sent from the controller 1C in step SA6 has been received. When the setting completion notification is received, the process proceeds to step SA12 indicated by a YES arrow. If the setting completion notification has not been received, step SA11 is repeated as indicated by the NO arrow, and the reception of the setting completion notification is awaited.

  In step SA12, the transmission of the sequence Seq [n−1] from which the transmission plug (TxB) originally transmitted data is stopped. Thereafter, in step SA13, the number of transmission sequences is reduced from n to n-1.

  In step SA14, a band corresponding to one sequence reduced in step SA13 is released. Then, it progresses to step SA15 and the process in the talker 1T is complete | finished.

  FIG. 6 is a conceptual diagram for explaining a first example of sequence increase processing according to the present embodiment. In this example, a case will be described in which the sequence is increased again after the first example of the sequence reduction process shown in FIG. 3 is executed.

  FIG. 6A is a conceptual diagram showing an initial state of sequence assignment before the sequence increase processing according to the present embodiment. In the initial state, a connection is set between the transmission plug (Tx1) and the reception plug (Rx1) and between the transmission plug (Tx2) and the reception plug (Rx2) using the sequences Seq [1] and Seq [2], respectively. ing. Further, a connection is set between the transmission plug (Tx3) and the reception plug (Rx3) via the sequence Seq [0]. The number of sequences at this time is “3”. That is, the talker 1T reserves a band for three sequences on the IEEE 1394 bus.

  Here, when a connection from the transmission plug [Tx0] to the reception plug [Rx0] is set, the sequence Seq [3] is added to the end of the sequence, and the transmission plug [0] is added to the increased sequence Seq [3]. Assigned to. Then, the data of the transmission plug [0] is transmitted via the transmission FIFO [3], and enters the state shown in FIG.

  Thereafter, as shown in FIG. 6C, the sequence received by the reception plug (Rx0) is set to the sequence Seq [3]. In this way, when there is a connection setting, it is possible to save unnecessary sequences by increasing the necessary number of sequences according to the connection setting, and to effectively use the resources of the IEEE 1394 bus. Can do.

  FIG. 7 is a conceptual diagram for explaining a second example of the sequence increasing process of the present embodiment.

  FIG. 7A is a conceptual diagram showing an initial state of sequence assignment before the sequence increase processing according to the present embodiment. In the initial state, connections are set between the transmission plugs (Tx0 to 2) and the reception plugs (Rx0 to 2) using the sequences Seq [0] to Seq [2], respectively.

  Here, when the connection from the transmission plug [Tx7] to the reception plug [Rx3] is set, the sequence Seq [3] is added to the end of the sequence, and the transmission plug [7] is added to the increased sequence Seq [3]. Assigned to. Then, the data of the transmission plug [7] is transmitted via the transmission FIFO [3], and enters the state shown in FIG.

  FIG. 8 is a flowchart showing the sequence increasing process according to this embodiment. Note that the dotted arrows in the figure indicate the flow of commands. This sequence increasing process is started when there is an instruction to set a connection from the transmission plug (TxA) of the designated talker 1T to the reception plug of the listener 1R.

  In step SB1, the process in the controller 1C is started, and in step SB2, a connection is set between the designated talker 1T transmission plug (TxA) and the designated listener reception plug (RxA). Thereafter, in step SB3, the talker 1T is requested to assign a sequence to the transmission plug (TxA), and the process proceeds to step SB4, where the processing in the controller 1C is terminated.

  In step SB5, processing in the talker 1T is started, and when an allocation request transmitted from the controller 1C is received in step SA3, a transmission plug (TxA) is allocated to an empty transmission FIFO in step SB6.

  In step SB7, a band corresponding to one sequence is secured on the IEEE 1394 bus. Thereafter, in step SB8, the sequence (data) handled by the transmission plug (TxA) is added to the end of the isochronous stream.

  In step SB9, the number of transmission sequences in the talker 1T is increased by one (Seq [n] → Seq [n + 1]). Thereafter, in step SA10, the transmission FIFO assigned the transmission plug (TxA) is assigned to the sequence Seq [n + 1], the process proceeds to step SB11, and the processing in the talker 1T is terminated.

  As described above, according to the embodiment of the present invention, the path between the transmission plug and the transmission FIFO can be dynamically changed. In addition, the number of transmission sequences can be changed dynamically.

  That is, according to the embodiment of the present invention, when a connection is disconnected, the number of sequences is decreased according to the disconnection of the connection, and the bandwidth on the IEEE 1394 bus corresponding to the decreased sequence is released, so that IEEE 1394 is released. Bus resources can be used effectively.

  In addition, according to the embodiment of the present invention, when a connection is set, it is possible to omit a useless sequence by increasing the necessary number of sequences according to the connection setting. Resources can be used effectively.

  Furthermore, according to the embodiment of the present invention, by combining the sequence reduction process and the increase process, only the bandwidth corresponding to the number of sequences corresponding to the number of transmission plugs for which connections with the reception plugs are actually set is provided. Since it can be secured on the bus, it is possible to eliminate a useless bandwidth for a sequence, and the resources of the IEEE 1394 bus can be effectively used.

  Note that this embodiment may be implemented by a general-purpose computer or the like in which a computer program or the like corresponding to this embodiment is installed.

  In that case, the computer program or the like corresponding to the present embodiment may be provided to the user while being stored in a storage medium that can be read by the computer, such as a CD-ROM or a floppy disk.

  Although the present invention has been described with reference to the embodiments, the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications, improvements, combinations, and the like can be made.

1 is a bus configuration diagram of a network 100 according to an embodiment of the present invention. FIG. It is a block diagram which shows the hardware constitutions of the communication node 1 (controller 1C, talker 1T, listener 1R) by the Example of this invention. It is a conceptual diagram for demonstrating the 1st example of the sequence reduction process of a present Example. It is a conceptual diagram for demonstrating the 2nd example of the sequence reduction process of a present Example. It is a flowchart showing the sequence reduction process by a present Example. It is a conceptual diagram for demonstrating the 1st example of the sequence increase process of a present Example. It is a conceptual diagram for demonstrating the 2nd example of the sequence increase process of a present Example. It is a flowchart showing the sequence increase process by a present Example. It is a conceptual diagram showing the establishment technique of the connection between the transmission plug and reception plug in the conventional IEEE1394 apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Data transfer apparatus (communication node), 1C ... Controller (control node), 1T ... Talker (transmission node), 1R ... Listener (reception node), 3 ... Communication network, 6 ... Bus, 7 ... RAM, 8 ... ROM , 9 ... CPU, 10 ... timer, 11 ... detection circuit, 12 ... operator, 13 ... display circuit, 14 ... display, 15 ... external storage device, 18 ... sound source circuit, 19 ... effect circuit, 20 ... sound system, 21 ... Communication I / F, 100 ... Network

Claims (8)

A data transfer device connected to a network capable of isochronous transfer composed of a plurality of data transfer devices,
Disconnection means for disconnecting a connection between a transmission plug of a transmission node connected to the isochronous transfer-capable network and a reception plug of a reception node;
Request means for requesting the transmission node to optimize the transmission sequence;
Receiving means for receiving, from the transmission node as a response to the optimization request, information on the transmission plug newly assigned to the transmission sequence used by the transmission node that has been disconnected;
A data transfer apparatus comprising setting means for setting a new connection between the newly assigned transmission plug and the reception plug that has disconnected the connection. The data transfer apparatus according to claim 1, further comprising transmission sequence request means for requesting the transmission node to add a new transmission sequence. A data transfer device connected to a network capable of isochronous transfer composed of a plurality of data transfer devices,
Receiving means for receiving a transmission sequence optimization request from a control node connected to the isochronous transferable network;
In accordance with the optimization request, a duplicating means for duplicating data sent by the transmission plug assigned to the first transmission sequence at the end of the data stream;
Sending means for sending the duplicated data in duplicate using a second transmission sequence in which no connection is established between the receiving plug of the receiving node connected to the isochronous transferable network;
Stop means for stopping transmission of data according to the first transmission sequence;
A data transfer apparatus comprising: a release unit that releases a band used by the first transmission sequence on a bus capable of isochronous transfer. The receiving means further receives a sequence addition request from the control node,
Furthermore, an acquisition means for acquiring a band for one sequence on the isochronous transfer-capable bus;
The data transfer apparatus according to claim 3, further comprising an adding unit that newly adds a transmission sequence that uses the acquired band. The data transfer device according to claim 1, wherein the network is a network capable of isochronous transfer. The data transfer apparatus according to claim 1, wherein the network is an IEEE 1394 network. A program executed by a data transfer device connected to a network capable of isochronous transfer constituted by a plurality of data transfer devices,
A disconnection procedure for disconnecting a connection between a transmission plug of a transmission node connected to the isochronous transfer-capable network and a reception plug of a reception node;
A request procedure for requesting the transmission node to optimize a transmission sequence;
A reception procedure for receiving, from the transmission node as a response to the optimization request, information on a transmission plug newly assigned to a transmission sequence used by the transmission node that has been disconnected;
A data transfer program comprising: a setting procedure for newly setting a connection between the newly assigned transmission plug and the reception plug that has disconnected the connection. A program executed by a data transfer device connected to a network capable of isochronous transfer constituted by a plurality of data transfer devices,
A reception procedure for receiving a transmission sequence optimization request from a control node connected to the isochronous transferable network;
In accordance with the optimization request, a duplication procedure for duplicating the data sent by the transmission plug assigned to the first transmission sequence at the end of the data stream;
A sending procedure for duplicating and sending out the duplicated data using a second sending sequence in which no connection is established with a receiving plug of a receiving node connected to the isochronous transferable network;
A stop procedure for stopping transmission of data according to the first transmission sequence;
A data transfer program comprising: a release procedure for releasing a band used on the bus capable of isochronous transfer in the first transmission sequence.

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