JP5088078B2 - Network system and communication device - Google Patents

Description

The present invention relates to a network system for transmitting an acoustic signal between a plurality of nodes and a communication device functioning as a node in such a network system .

  2. Description of the Related Art Conventionally, an audio network system for transmitting an acoustic signal between a plurality of nodes is known and used in concerts, plays, music production, private broadcasting, and the like. As examples of such an audio network system, CobraNet (trademark) and EtherSound (trademark) as described in Non-Patent Documents 1 and 2 below are known.

"CobraNet (TM)", [online], Valcom Corporation, [March 21, 2006 search], Internet <URL: http://www.balcom.co.jp/cobranet.htm> Carl Conrad, "EtherSound (TM) in a studio environment", [online], Digigram SA, [March 21, 2006 search], Internet <URL: http://www.ethersound.com/news/getnews. php? enews_key = 101>

  In addition, in general, an audio network system arbitrarily includes an audio device having various functions such as analog input, analog output, digital input, digital output, mixing, effect addition, recording / playback, remote control, or a combination thereof. It is desired to be able to connect.

However, such a conventional audio network system has the following problems.
That is, for example, in CobraNet (trademark), since frames (multiple frames) respectively created by a plurality of nodes are transmitted to a bus type network, there is a problem that gaps between frames occur and transmission efficiency is poor.

In addition, since the number of channels (ch) that can be physically transmitted changes due to changes in the connection (configuration of the network) between the nodes, the necessary number of channels can be transmitted in consideration of the frame transmission route. The system had to be configured, and there was a problem that it was difficult to design.
This is because the time until data arrives depends on the number of nodes from the source node to the terminal node, and the next communication is not performed until the data reaches all nodes. This is because data transfer takes time and bandwidth is lost.

In addition, EtherSound (trademark) does not take measures to prevent sound interruption when a failure occurs, and there is a problem that the sound stops when the connection between nodes is disconnected. Since a frame includes a plurality of packets, transmission control is complicated, and there is a problem that the amount of data that can be transmitted per time is not sufficient.
Furthermore, as in the case of CobraNet (trademark), the system must be configured so that the necessary number of channels can be transmitted in consideration of the transmission route of the frame, and there is a problem that the design is difficult.

Therefore, the present applicant has proposed an audio network system having a ring-type transmission path that circulates a voice transmission frame at a predetermined cycle as a technique for solving these problems (Japanese Patent Application No. 2006-84253).
In this network system, waveform data is solidly recorded in a voice transmission frame, so that management is simple and voice transmission can be performed using the communication band without waste. Further, since all the nodes in the system are circulated in the voice transmission frame, the connection between the nodes can be easily changed without paying particular attention to the frame transmission route.

In addition, when a node capable of configuring the system is connected, the network system automatically determines a master node for generating a voice transmission frame, and shifts to a mode for transmitting a voice signal between the connected nodes. It is the composition to do.
In this network system, even if the transmission path of the voice transmission frame is cut off due to cable disconnection or node abnormality after the transition to the voice signal transmission mode, on the side where the master node exists The transmission path can be shrunk at the position where the disconnection occurs, and the transmission of the voice transmission frame can be continued within the range of the reduced transmission path.

However, in this network system, there is a problem in that data transmission using a ring-type transmission path cannot be performed on the side where the master node does not exist among the systems divided by disconnection.
On the other hand, in addition to waveform data, various data such as commands and Ethernet frames may be described and transmitted in a frame that circulates in a ring-type transmission path, and the data may be exchanged between nodes. Accordingly, there has been a demand for maintaining data transmission using a ring-type transmission path even for a device that has been disconnected from the master node.
The above-described network systems have not been able to meet such requirements sufficiently.

  The present invention solves such a problem, and generates a voice transmission frame having a plurality of acoustic signal storage areas generated by a master node along a loop-shaped transmission path formed between devices at a constant cycle. When configuring a network system to be circulated, even if there is a device group that has been disconnected from the master node for some reason, a frame that circulates between the device groups along a loop-shaped transmission path at a fixed period The purpose is to enable data transmission using the.

In order to achieve the above object, a network system according to the present invention includes a plurality of nodes each including two sets of receiving means and transmitting means for performing unidirectional communication, and a set of receiving means and transmitting means for a certain node. in the network system formed by sequentially connecting by a set of transmission means and receiving means and each of the nodes connected, to each node, which is defined as the temporary master node to one of the plurality of nodes the master node of the extraordinary produces, circulates at a constant period along the loop-shaped transmission path transmission frame having a storage area of the initial communication frame is formed between the nodes for the command transmission, each node The initial communication is performed between a series of connected nodes by writing and / or reading the initial communication frame in the transmission frame. Temporary communication mode for transmitting the frame, and one of which is defined as the master node, the master node generates, audio transport frame by each node having a storage area of a plurality of audio signals among the plurality of nodes Sound signals between a series of connected nodes by circulating at regular intervals along a loop-shaped transmission path formed between them and writing and / or reading sound signals to / from the sound transmission frame at each node. Communication control means for selectively executing communication in a voice transmission mode for performing transmission of data, and when the master node is set in the network system, the voice transmission to each of the nodes under the control of the master node Mode operation is started and the connection between the nodes is cut off at any point in the network system Of the two node groups generated by the disconnection, each node of the node group on the side where the master node exists maintains the operation of the voice transmission mode and is in a loop transmission path formed by each node. Accordingly, the circulation of the voice transmission frame is continued, and each node of the node group on the side where the master node does not exist automatically shifts to the operation in the temporary communication mode.

In such a network system, the communication control means of each node is a means capable of operating in the initial communication mode for transmitting the initial communication frame from the transmitting means to an adjacent node connected to the transmitting means. Yes, and means that operates in the initial communication mode when the node is started or reset, and is located at the end of the loop-shaped transmission path formed in the voice transmission mode or the temporary communication mode in the network system When a node detects that a node operating in the initial communication mode is directly connected to the own node, the node accesses the node operating in the initial communication mode and makes the node the loop-like node to which the own node belongs. A node that is incorporated in the transmission path and is operating in the above-mentioned temporary communication mode is directly connected to its own If this is detected, a reset command is sent to the node operating in the ad hoc communication mode to reset it, the node operation is returned to the initial communication mode, the node is accessed, and the node is It is preferable to perform an operation for incorporation into a loop transmission path to which the own node belongs.

Further, when the reset command is received by each of the nodes, the function of the own device relating to the formation of the loop-shaped transmission path is reset to leave the loop-shaped transmission path and the reset command is received. It is preferable to provide a reset transmission means for transmitting a reset command to an adjacent node on the opposite side to the side.

Further, when the node operating in the initial communication mode detects that the node operating in the initial communication mode is directly connected to the own node, the node is negotiated with the detected node, One of the detected nodes is set as the temporary master node, the local node and the detected node are shifted to the temporary communication mode, and the loop-shaped transmission path between the local node and the detected node It is good to form.
Furthermore, the node located at the end of the loop transmission path formed in the voice transmission mode or the temporary communication mode forms a loop transmission path different from the own node and is operating in the voice transmission mode. When it is detected that this node is directly connected to the own node, it is preferable not to perform the operation of incorporating the detected node into the loop transmission path to which the own node belongs.
In another network system of the present invention, a plurality of nodes each having two sets of receiving means and transmitting means for performing unidirectional communication are provided, and one set of receiving means and transmitting means of a certain node is set as one of the next node. A network system formed by sequentially connecting a pair of transmitting means and receiving means, wherein the plurality of nodes are respectively connected to their receiving means and transmitting means. An initial communication mode for bidirectional communication with adjacent nodes, and one of the plurality of nodes is defined as a temporary master node, and the temporary master node generates a command transmission A transmission frame having a storage area for an initial communication frame circulates at a constant cycle along a loop-shaped transmission path formed between the nodes. A temporary communication mode for transmitting an initial communication frame between a series of connected nodes by writing and / or reading the initial communication frame to / from the transmission frame at each node, and one of the plurality of nodes An audio transmission frame having a storage area for a plurality of acoustic signals generated by the master node is circulated at a constant cycle along a loop-shaped transmission path formed between the nodes. Each node can write and / or read an acoustic signal to / from the audio transmission frame, thereby selecting communication in one of the audio transmission modes for transmitting the acoustic signal between a series of connected nodes. And detect that a new node is connected to a node located at the end of the network system, and respond to the detection. Identifying whether the other network system formed by one or more nodes including the new node is operating in the initial communication mode, the temporary communication mode, or the voice transmission mode. If the mode of the network system is a mode lower than the mode of the network system, the other network system is incorporated into the network system, and the mode of the other network system is a mode higher than the mode of the network system. In some cases, the network system is controlled to be incorporated into the other network system.
Further, in the network system, the initial communication mode, the temporary communication mode, and the voice mode are set to the lowest mode and the voice transmission mode is set to the highest mode, and the built-in The network system may be configured to execute communication in a mode that is executed by the previous network system that is incorporated.
Further, the initial communication mode is a mode that is executed when the number of nodes constituting the network system is 1, and when both the network system and the other network system are operating in the initial communication mode, One of the nodes forming both network systems may be determined as a temporary master node to start communication in the temporary communication mode.
Further, at least one of the nodes may be provided with a master node determining means for determining one node functioning as the master node in the voice transmission mode from the nodes constituting the network according to a user operation. .
Further, the communication device of the present invention is a communication device functioning as the node in a network system formed by connecting a plurality of nodes, and receives a plurality of signals received from one adjacent node along the transmission path of the network system. In an audio transmission mode in which an audio signal is written to and / or read from an audio transmission frame having a storage area for the audio signal, and the audio transmission frame is sent to another node adjacent along the transmission path of the network system. Detecting that there is no communication node for performing communication between the adjacent nodes and a master node for controlling the voice transmission frame on the network system, and in response to the detection, the voice transmission frame is detected. Instead of sending and receiving and transmitting transmission frames with storage areas for command transmission. To the write data indicating the command or response to a transmission frame and / or temporary communication mode for reading, is provided with a communication control means for automatically shifts the operation of the communication means.
In such a communication apparatus, when the communication control means determines whether or not the communication apparatus should operate as a temporary master node in the temporary communication mode, and determines that it should operate as a temporary master node In addition, it is preferable to periodically generate the transmission frame and send the generated transmission frame to the other adjacent nodes.
Further, the communication control means shifts the operation of the communication means from the temporary communication mode to the voice transmission mode in response to setting of a master node for controlling the voice transmission frame in the network system. It is good to.

According to the network system and the communication device of the present invention as described above, the audio transmission frame having a plurality of acoustic signal storage areas generated by the master node is formed along the loop-shaped transmission path formed between the devices. When configuring a network system that circulates at a fixed cycle, even if there is a device group that has been disconnected from the master node for some reason, a fixed cycle is performed along the looped transmission path between the device groups. It is possible to perform data transmission using a frame that is circulated in the network.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
1. 1. Outline of Audio Network System of Embodiment of Present Invention 1.1 Overall Configuration First, FIG. 1 shows an outline of an audio network system which is an embodiment of a network system of the present invention.
As shown in FIGS. 1A and 1B, the audio network system 1 is a set of a reception interface (I / F) that is a reception unit that performs unidirectional communication and a transmission I / F that is a transmission unit. Are configured by sequentially connecting nodes A to C having two sets of communication cables CB. Here, an example of three nodes is shown, but the number of nodes may be arbitrary.

  In the node A, the reception I / F_AR1 and the transmission I / F_AT1 are a set of I / Fs, and the reception I / F_AR2 and the transmission I / F_AT2 are another set of I / Fs. For nodes B and C, the I / F in which the first character “A” of the code is replaced with “B” or “C” has the same relationship.

The connection between the nodes is performed by connecting one set of reception I / F and transmission I / F to one set of transmission I / F and reception I / F of another node through a communication cable CB. Yes. For example, between the node A and the node B, the reception I / F_AR2 and the transmission I / F_BT1 are connected, and the transmission I / F_AT2 and the reception I / F_BR1 are connected. Further, between the node B and the node C, another set of I / F of the node B and one set of I / F of the node C are connected.
Each node shown in FIG. 1 is an acoustic signal processing device having various functions such as analog input, analog output, digital input, digital output, mixing, effect application, recording / playback, remote control, or a combination thereof. Of course, it does not matter if the function is different for each node.

Here, as shown in (a), a state in which each node is connected like a single line having an end is referred to as “cascade connection”. In this case, one ring-shaped data transmission path can be formed by the cable CB connecting the nodes as shown by a broken line, and each node transmits the frame so as to circulate at a constant cycle. By reading and writing necessary information with respect to the frame, data can be transmitted / received to / from any node on the path. In this way, an operation mode in which one ring-shaped data transmission path is constructed in the system is referred to as “single mode”.
In the audio network system 1, one node becomes a master node, generates a frame for transmitting an acoustic signal, periodically circulates the transmission path, and manages the network. The frame generated by the master node is referred to as a “TL frame” in distinction from other frames.

  Further, in addition to the cascade connection shown in (a), when the I / Fs not used in the nodes at both ends are also connected by the communication cable CB, two ring-shaped data transmission paths are provided as shown in (b). Can be formed. Each node can transmit / receive data to / from any node on the path by transmitting a frame through these paths and reading / writing necessary information for each frame. Such a connection state between nodes is referred to as “loop connection”. An operation mode in which two ring-shaped data transmission paths are constructed in the system is referred to as “twin mode”.

  However, in the audio network system 1, the single mode operation is a basic type, and whether or not the twin mode operation is permitted is set in the master node. When the setting for not permitting the twin mode operation is made, the single mode operation is continued even when the loop connection is made, as will be described later. Therefore, the connection state and the operation mode do not necessarily correspond.

In addition, although two cables are shown in FIG. 1, if a pair of reception I / F and transmission I / F are provided close to each other or integrally, two cables are bundled into one, It is also possible to connect a pair of I / Fs.
If each node is provided with the necessary I / F, as shown in (c), the external device N is connected, and the data received from the external device N is written in the TL frame and transmitted to other nodes. It is also possible to transmit data read from the TL frame to the external device N.

  As such an external device N, for example, an external console can be considered. Then, the console transmits a command corresponding to the operation received from the user to the node B, and the node B writes this in the TL frame and transmits it to the other node, or the other node writes in the TL frame and transmits it. It is conceivable that the node B reads out a response, level data, and the like, transmits it to the console, and performs an operation such as using the console to display the operator state or level.

1.2 Configuration of TL Frame Next, FIG. 2 shows a configuration example of a TL frame transmitted through the transmission path described above. FIG. 3 shows a more detailed configuration of the waveform data area, the Ethernet frame area, and the ITL frame area in the TL frame. Note that the width of each area shown in these figures does not necessarily correspond to the data amount.

  As shown in FIG. 2, this TL frame 100 is 1282 bytes in size, and in order from the top, is a preamble 101, management data 102, a waveform data (audio data) area 103, a control data area 104, an FCS (Frame Check Sequence). ) 105 areas. The size of each area is constant regardless of the amount of data described in that area. Moreover, the size of each area | region other than FCS105 shown here is an example, and may be changed suitably.

  The preamble 101 is a total of 8 bytes of data, and describes a preamble and an SFD (Start Frame Delimiter) defined by IEEE (Institute of Electrical and Electronic Engineers) 802.3.

  In the audio network system 1, since the frame transmitted from the transmission I / F reaches only the reception I / F connected by the single connection cable CB, the address description is not very meaningful. Therefore, it is not necessary to describe the destination address in the TL frame 100, and no description area is provided here.

  The management data 102 is 8-byte data, and is used as data used by each node in the audio network system 1 to manage data included in the TL frame. A ring ID indicating which transmission path is to be circulated, a frame ID which is a frame serial number, the number of channels of waveform data in the waveform data 103, and the like are described. As the frame type, data indicating that this frame is a TL frame is described. When the twin mode is not permitted, the ring ID is a fixed value because there is only one transmission path in the system.

  Further, 1024 bytes are secured as the waveform data area 103, and one sample of 32 bits of waveform data, which is data of the acoustic signal, can be described for 256 channels. That is, in this system, by circulating one TL frame 100, it is possible to transmit acoustic signals for 256 channels. Note that it is not necessary to worry about what is described in the area of ch (empty ch) that is not used for transmission in 256 ch. In this embodiment, even when the number of bits of waveform data to be transmitted is not 32 bits, for example, 16 bits or 24 bits, a 32-bit area is prepared for each channel and described in the area. However, the size of each channel area may be changed according to the number of bits of the waveform data. In this case, 16-bit waveform data can be transmitted for 512 channels, and if it is 24 bits, 340 channels can be transmitted.

  Further, as shown in FIG. 3A, in the waveform data area 103, a channel is assigned to each node constituting the audio network system 1 in advance, and each node is located at the position of the channel assigned to itself. Write output waveform data. This channel assignment is performed by a controller (for example, a control CPU of any node or the external device shown in FIG. 1C) that controls the entire system, and can be changed as appropriate during the operation of the system. . Further, it is not necessary to assign ch at consecutive positions for each node, and there may be empty ch that is not assigned to any node.

On the other hand, 238 bytes are secured as the control data area 104, and an Ethernet frame area 106, an ITL frame area 107, and a management data area 108 are provided here.
The Ethernet frame area 106 includes an IEEE (Institute of Electrical and Electronic Engineers) 802.3 format frame (Ethernet frame) obtained by further framing IP packets, which are packets for inter-node communication based on IP (Internet Protocol). Is described.

Also, if the Ethernet frame to be described does not fit in the prepared size (here 178 bytes), it is divided into the required number of blocks on the frame transmission side, and one block is described for each TL frame. To do. Then, on the frame receiving side, data is extracted from a plurality of TL frames 100 and combined, and the frame before division is restored, so that Ethernet frames are transmitted between nodes in the same manner as normal Ethernet (registered trademark) transmission. can do.
The maximum size of the IEEE802.3 format frame is 1526 bytes. On the other hand, even if several bytes of division control data are added for division / restoration control, about 170 bytes can be transmitted for each TL frame. Transmission of one Ethernet frame is completed in a maximum of 9 frames.

FIG. 3B shows details of data described in the Ethernet frame area 106.
Among these, the number of blocks is information indicating how many blocks the frame to be transmitted is divided into.
The block number is information indicating what number of blocks the corresponding block is divided.
The transmission source ID is information indicating a node that has written data to the Ethernet frame area 106. A free token to be described later can be described by setting the transmission source ID to a special value. Further, the transmission source ID can be described by the MAC address of the device. Each device that is a node of the audio network system 1 has two transmission I / Fs and two reception I / Fs. However, each device does not have a separate MAC address, but has one MAC address as a device. Have.

The data size is information indicating the size of the frame data described in the corresponding block.
Frame data is data of an Ethernet frame to be transmitted. The last block has an empty area at the end, but there is no problem if the receiving side reads only an area with data in accordance with data size information.

In the ITL frame area 107, data of an ITL frame that is a frame used for transmission of a command and a response to the command between adjacent nodes is described. As will be described later, this ITL frame is used for information transmission at the initial stage of system formation and also for information transmission after system formation.
Also here, as in the Ethernet frame area 106, if the ITL frame to be described does not fit in the prepared size (50 bytes here), it is divided into the required number of blocks on the frame transmission side. Then, it can be restored by combining them on the receiving side.

FIG. 3C shows details of data described in the ITL frame area 107.
The number of blocks, block number, data size, frame data, and free area shown in this figure have the same meaning as in the case of the Ethernet frame area 106 described above.
However, in the case of an ITL frame, it is basically used for transmitting information to adjacent nodes. Even when transmitting to a distant node, as will be described later, transmission is performed by a method in which an intermediate node once refers to the content and then transmits a frame having the same content to the next node. Therefore, the node that has written data in the ITL frame area 107 is always a node adjacent to the node that has received the TL frame (the node that is directly connected to the reception I / F that has input the TL frame). Therefore, it is not necessary to describe the transmission source node ID in the ITL frame area 107 (however, as described later, the MAC addresses of these nodes are described in the ITL frame itself as information indicating the transmission source node and the destination node. ).

The management data area 108 is an area in which data used by each node in the audio network system 1 for managing data included in the TL frame is described. As data described here, for example, a disconnection detection flag SDF indicating that the TL frame 100 is disconnected during transmission, an error flag EDF indicating that an error has occurred in the transmission of the TL frame 100, and a level display are used. For example, level data.
The reason why a dedicated area (here, 10 bytes each) for describing the ITL frame and management data is provided in the control data area 104 is to constantly transmit the data.
The FCS 105 is a field for detecting frame errors defined by IEEE 802.3.

Next, FIG. 4 shows the data structure of the ITL frame.
There are two types of ITL frames, and writing into the ITL frame area 107 is in the normal format shown in FIG. Shown in (b) is an ITL frame format used for special purposes.
Among these, the normal ITL frame 110 shown in FIG. 4A includes a preamble 111, a frame type 112, a data size 113, a transmission source ID 114, a destination ID 115, a transmission source port 116, a command type 117, a parameter 118, dummy data 118a, and FCS 119. It consists of each area.

Of these, the format of the preamble 111 and the FCS 119 is the same as that of the TL frame 100 shown in FIG.
The frame type 112 is data having the same meaning as the frame type described as the management data 102 in the TL frame 100. However, here, data indicating that this frame is an ITL frame is described.
If the frame type is described in the first byte of the management data 102 in the TL frame 100, the preamble 111, the frame type 112, and the FCS 119 have a common format in the TL frame 100 and the ITL frame 110.

As the data size 113, information indicating the data amount in the frame excluding the dummy data 118a is described.
As the transmission source ID 114 and the destination ID 115, the MAC addresses of the transmission source device and the destination device are described, respectively.
As the transmission source port 116, information indicating from which transmission I / F the transmission I / F included in each node is transmitted is described.
As the command type 117, a command ID indicating which command (or response) is transmitted by the ITL frame 110 is described. Some examples of command content will be given later.
As the parameter 118, different parameter data is described for each command.
The dummy data 118a is data having no particular meaning for making the frame length constant.

Also, the special ITL frame 120 shown in (b) includes only the preamble 111, the frame type 112, and the FCS 119. The format of these data is the same as that of the ITL frame 110. In the case of the ITL frame 120, information indicating the use of the frame is described as the information of the frame type 112.
The ITL frame 120 having such a format is used in the audio network system 1 for special purposes such as distance measurement between nodes and a disconnection notification described later. Hence, “110” is used as the code of the ITL frame, but the ITL frame 120 can be handled in the same manner unless otherwise specified.

1.3 TL Frame Transmission Method Next, FIG. 5 shows the transmission timing of the TL frame 100 shown in FIG.
As shown in this figure, in the audio network system 1, the TL frame 100 is circulated between nodes every 10.4 μsec (microseconds), which is one sampling period of 96 kHz (kilohertz). Is configured to write an acoustic signal to a desired channel of a TL frame or read an acoustic signal from a desired channel. Therefore, one sample of waveform data can be transmitted between the nodes for each of 256 transmission channels in each sampling period.

If data transfer of Ethernet (registered trademark) system of 1 Gbps (Gigabit per second) is adopted, the time length of the TL frame 100 is 1 nanosecond × 8 bits × 1282 bytes = 10.26 μsec, and 1 sampling period The transmission is completed within.
In the case of 1282 bytes, if the time interval between frames is ignored, it can be calculated up to a sampling period of 1 sec / 10.26 μsec = 97.47 kHz, and if it is 96 kHz, it is 10.4 μsec / Transmission is possible up to a frame size of 8 bits / 1 nanosecond = 1300 bytes. However, a space of a predetermined time or more is required between frames, and the frame transmission timing may fluctuate back and forth. Therefore, the size (time length) of the TL frame is determined in consideration of them. .

Next, FIG. 6 shows a transmission state of the TL frame shown in FIG. 2 when an acoustic signal is transmitted (audio transmission mode) on the audio network system 1. FIG. 6 shows an example in the single mode.
Here, an audio network system in which four nodes from node A to node D are cascade-connected is considered. When the TL frame 100 shown in FIG. 2 is circulated to each node in this system, one of the nodes is determined as a master node, and only that node is a TL frame with a new sampling period (a TL frame with a different serial number). ) Is generated, and the TL frame generated every sampling period is transmitted to the next node. Nodes other than the master node are slave nodes, each of which performs a transfer process of receiving a TL frame from the previous node and transmitting it to the next node.

  Then, when the master node B first transmits a TL frame toward the node C in the right direction in accordance with the timing of the word clock, the TL frame is transmitted from the node B → C → D → as shown by the broken line. The data is transmitted in the order of C → B → A → B and returns to the node B. When viewed from the master node, the side that first transmits a TL frame that makes a round is called the front side, and the side that transmits the second time is called the rear side. In this transmission, each node reads waveform data and control data to be received from another node from the TL frame and transmits the waveform data to be transmitted to the other node after receiving the TL frame. Data and control data are written into the TL frame.

  Then, when the TL frame returns around the transmission path once, the master node rewrites the management data 102 of the TL frame to generate a TL frame having a later sample period, and transmits it at an appropriate sample period. Provide. At this time, the master node also reads / writes data from / to the TL frame in the same manner as other nodes. The generation of the TL frame will be described in detail later.

  By repeating the above, each node can be circulated in one TL frame per sampling period as shown in time series from (a) to (e). In these drawings, the black arrow indicates the beginning of the TL frame, and the black circle indicates the end of the TL frame. Line arrows are described for easy understanding of TL frame breaks.

  Each slave node does not need to read / write data or transmit to the next node after receiving all of the TL frames. When receiving the required number of bytes from the beginning, each slave node reads / writes data to the next node. You may have started the process of sending. After that, it is sufficient to read / write and transmit data at almost the same speed as the reception until the end of the TL frame. However, for the master node, as described later, it is preferable to generate a new TL frame based on the contents after receiving all of the TL frames.

  In the single mode, the nodes other than the nodes at both ends pass the TL frame twice in one cycle. Of these, data other than the ITL frame area 107 is read / written only once. It is. Which of the reading and writing is performed may be arbitrarily determined when the TL frame is first passed or when the TL frame is passed rightward in the drawing. When reading and writing is not performed, it is only necessary to rewrite only the transmission source address and presence confirmation information described later, and to pass through the remaining portion of the TL frame.

  It is preferable that the ITL frame can be transmitted to adjacent nodes in both directions. Therefore, when passing the TL frame in the right direction in the figure, the data of the ITL frame to be transmitted to the adjacent node on the right side (or the node ahead thereof) is written in the ITL frame area 107, and the TL frame is passed in the left direction in the figure. In some cases, ITL frame data to be transmitted to the adjacent node on the left side (or a node ahead thereof) may be written in the ITL frame area 107 and transmitted.

  Also, in each node, the frequency and timing of rewriting TL frame data and the frequency and timing of the receiving side network clock (corresponding to the operating clock of the transmitting node) and the transmitting side network clock (corresponding to the operating clock of the node) In order to absorb the difference, it is necessary to perform buffering at the time of receiving the TL frame, so that there is some time lag from the start of reception of the TL frame to the start of transmission.

  Then, if you want to minimize the transmission delay (sampling period unit) of the acoustic signal transmitted over the network, considering the amount of time lag above, the TL frame that started transmission at the timing of a word clock with a master node, The master node may be configured to be able to complete reception at a timing preceding the next next word clock by a predetermined time α (corresponding to a time related to preparation of a new TL frame in the master node).

As will be described in detail later, in this case, for example, based on the Sth TL frame, an S + 2nd TL frame to be transmitted two sampling periods ahead is generated.
However, it is not indispensable to generate a TL frame to be transmitted two sampling periods ahead. Based on the S-th TL frame, k is an S + k-th TL frame to be transmitted ahead k sampling periods. It is also possible to generate it. In this case, k is referred to as “periodic update amount k”.

  In general, according to the value of k, the master node can complete the reception of the TL frame that has started to be transmitted at the timing of a certain word clock by a predetermined time α before the word clock ahead of k cycles. If so, transmission of acoustic signals is possible. Therefore, even when the number of nodes increases and the time until the transmitted TL frame returns to the master node increases, the state in which the acoustic signal can be transmitted can be maintained by increasing the value of k.

The periodic update amount k may be appropriately set by the master node, and the contents thereof may be transmitted to all the nodes in the system by broadcasting a parameter setting frame indicating the setting of the periodic update amount k.
However, in this system, since the timing of the acoustic signal received at each node is matched with each other, k is increased so that the delay in the completion of reception of the TL frame at the master node can be allowed (the allowable amount is in units of word clocks). The transmission delay is generated in units of word clocks in the transmitted acoustic signal.

  In this system, if the number of nodes is such that the TL frame can be circulated once within one sampling period by performing data transmission in the above manner, the network always responds to the size of the TL frame. A certain transmission bandwidth can be secured. This bandwidth is not affected by the amount of data transmission between specific nodes.

  In the case of the twin mode, as can be seen from FIG. 1, the transmission path for transmitting the TL frame generated by the master node B and transmitted rightward in the figure in the order of the nodes B → C → D → A → B. Then, a transmission path for transmitting the TL frame generated by the master node B and transmitted to the left in the figure in the order of node B → A → D → C → B can be formed. And then. During this transmission, each node reads the waveform data and control data to be received from other nodes from the TL frame and receives the waveform data to be transmitted to the other nodes until it is transmitted after receiving the TL frame. Write control data to the TL frame.

In the twin mode, since each TL frame passes through all the nodes once while going around the transmission path, each node reads and writes data during the passage.
Then, as a whole of the audio network system 1, duplex communication for writing and circulating the same data in the frames of the two transmission paths, and double communication for writing and circulating different data in the frames of the two transmission paths, It can be done selectively.

Of these, in the case of duplex communication, the same data is described even if there are two frames, so the amount of information that can be transmitted per sampling period, that is, the communication bandwidth is the same as in the case of cascade connection. is there. However, even if a disconnection occurs at one location, it is possible to quickly shift to cascade connection transmission and maintain data transmission with the same bandwidth. Further, by comparing the contents of the two frames, it can be confirmed whether or not the data is correctly transmitted.
On the other hand, in the case of doubling communication, since data for two frames can be transmitted per sampling period, the bandwidth of communication can be doubled in the case of cascade connection.
Which to do is set in the master node.

1.4 Hardware Configuration and Basic Operation of Each Device that Configures the System Next, hardware for transmitting a TL frame as described above and its operation will be described.
First, FIG. 7 shows a hardware configuration of an acoustic signal processing device that is each node constituting the audio network system 1 described above.
As shown in FIG. 7, the acoustic signal processing device 2 includes a CPU 201, a flash memory 202, a RAM 203, an external device I / F (interface) 204, a display 205, and an operator 206, which are connected by a system bus 207. Has been. A card I / O (input / output unit) 210 connected to the external device I / F 204 and the system bus 207 is also provided.

  The CPU 201 is a control unit that performs overall control of the operation of the acoustic signal processing device 2, and controls the display on the display unit 205 by executing a required control program stored in the flash memory 202, The operation of the child 206 is detected, parameter value setting / changing and operation of each part are controlled according to the operation, a command is transmitted to another acoustic signal processing device via the card I / O 210, and the card I / O Processing according to a command received from another acoustic signal processing apparatus via O210 is performed.

The flash memory 202 is a rewritable non-volatile storage unit that stores a control program executed by the CPU 201 and data that should remain even after the power is turned off.
The RAM 203 is a storage unit that stores data to be temporarily stored or used as a work memory for the CPU 201.

The external device I / F 204 is an interface for connecting various external devices to perform input / output. For example, an external display, a mouse, a keyboard for inputting characters, an operation panel, a PC (personal computer), and the like are connected. Interface is prepared.
The external device I / F 204 is also connected to the audio bus 217 of the card I / O 210. The waveform data flowing through the audio bus 217 is transmitted to the external device, and the waveform data received from the external device is input to the audio bus 217. You can do it.

The display unit 205 is a display unit that displays various information according to control by the CPU 201, and can be configured by, for example, a liquid crystal display (LCD) or a light emitting diode (LED).
The operation element 206 is for accepting an operation on the acoustic signal processing apparatus 2 and can be constituted by various keys, buttons, dials, sliders, and the like.

  The card I / O 210 also includes an audio bus 217 and a control bus 218. By mounting various card modules on these buses, input / output of acoustic signals and control signals to the acoustic signal processing device 2 and processing thereof are performed. It is an interface that allows you to do it. Each card module mounted here transmits / receives waveform data to / from each other via the audio bus 217, and transmits / receives a control signal to / from the CPU 201 via the control bus 218, and is controlled by the CPU 201.

  The audio bus 217 is an acoustic signal transmission local bus that time-divisionally transmits a plurality of channels of waveform data one sample at a time based on a sampling period from an arbitrary card to an arbitrary card. Any one of a plurality of connected cards becomes a master, and controls the reference timing of time division transmission of the audio bus 217 based on a word clock generated and supplied by the card. Each other card becomes a slave and generates a word clock for each card based on the reference timing.

  That is, the word clock generated by each card becomes a common clock synchronized with the word clock of the card serving as the master, and the plurality of cards in the node process the waveform data at the common sampling frequency. Furthermore, each card transmits the waveform data processed based on its own word clock and the waveform data to be processed to other cards via the audio bus 217 at the time division timing based on the reference timing, and Receive from another card.

FIG. 7 shows an example in which DSP (digital signal processor) cards 211 and 212, an analog input card 213, an analog output card 214, and a network I / F card 215 are mounted on the card I / O 210.
Various cards mounted on the card I / O 210 execute waveform data processing corresponding to the function of the card at a timing based on the word clock (waveform data sampling period).

  Among these, the DSP cards 211 and 212 are signal processing means for performing various processes such as mixing, equalizing, and applying effects on the waveform data acquired from the audio bus 217 at timing based on the word clock. The processed data is also output to the audio bus 217. Further, it can receive and process input of waveform data of a plurality of channels and output waveform data of a plurality of channels.

The analog input card 213 includes an A / D (analog / digital) conversion circuit, and has a function of converting an analog acoustic signal input from a voice input device such as a microphone into digital waveform data and supplying the digital waveform data to the audio bus 217. . It is also possible to process signals of a plurality of channels in parallel.
The analog output card 214 includes a D / A (digital / analog) conversion circuit, converts the digital waveform data acquired from the audio bus 217 into an analog acoustic signal, and outputs it to an audio output device such as a speaker. Have.

The network I / F card 215 includes two sets of a transmission I / F and a reception I / F. The transmission of the TL frame 100 and the ITL frame 110 described with reference to FIGS. And a function of reading and writing control data and the like. Details thereof will be described later. In addition, a plurality of network I / F cards can be mounted on the card I / O 210, and each network I / F card can be connected to a separate audio network. In this case, the acoustic signal processing device 2 performs an operation as a bridge that connects a plurality of audio networks.
In addition to those listed here, it is conceivable that various card modules such as a digital input / output, a sound source, a recorder, and an effector can be mounted as the other card 216.

  As described above, the card attached to the card I / O 210 processes the acoustic signal according to the common word clock. However, if the acoustic signal processing device 2 is a master node, 1 supplies a word clock to other cards including the network I / F card 215, and the network I / F card 215 transmits a TL frame every sampling period as a master node. When the audio signal processing device 2 is a slave node, the network I / F card 215 generates (reproduces) a word clock based on the reception timing of the TL frame, and transmits the word to other cards attached to the card I / O 210. Supply the clock.

Next, FIG. 8 shows the configuration of the network I / F card 215 in more detail.
As shown in FIG. 8, the network I / F card 215 includes first and second reception I / Fs 31 and 33 and first and second transmission I / Fs 34 and 32 used for frame transmission / reception, and A frame processing unit 220 that performs processing related to data transmission / reception using frames, and an upper layer I / F 70 that serves as an interface with the acoustic signal processing device 2 other than the network I / F card 215.

  Among these, the first and second reception I / Fs 31 and 33 and the first and second transmission I / Fs 34 and 32 correspond to the two sets of reception I / F and transmission I / F shown in FIG. It is a communication means and is provided with a predetermined connector (female side) for connecting to each communication cable. When connecting the communication cables, the first reception I / F 31 and the first transmission I / F 34 are set as one set, and the second transmission I / F 32 and the second reception I / F 33 are set as one set. These I / Fs may be I / Fs that perform data communication by any communication method as long as they have sufficient ability to transmit the TL frame within one sampling period described above. An I / F that performs 1 Gbps Ethernet data transfer is employed.

  Currently, for 1G Ethernet, 1000BASE-T using a CAT5e cable with an RJ45 connector (unshielded twisted pair) as a communication cable CB and 1000BASE-X using an optical fiber or an STP cable (shielded twisted pair) are used. There are various types, any of which can be used in the present embodiment. In addition, broadband network technology other than 1G Ethernet may be used. For example, FiberChannel, SDH (Synchronous Digital Hierarchy) / SONET (Synchronous Optical NETwork), and the like.

  The reception I / F extracts a network clock as a carrier from an electric signal or an optical signal propagating through the communication cable CB, and digitally performs byte unit (or word unit) from the electric signal or optical signal based on the extracted clock. Demodulate the data string of data and output it. The transmission I / F inputs a network clock and a digital data string in byte units (or word units) to be transmitted, modulates the network clock into an electric signal or optical signal for transmission, and outputs it to the communication cable CB. To do.

The upper layer I / F 70 is an interface for inputting / outputting data to / from the audio bus 217 and the control bus 218 shown in FIG.
Here, five data input / output ports are provided, and two of these IP_Packet ports generate an IP packet or an Ethernet frame included in the Ethernet frame read from the Ethernet frame area 106 of the TL frame 100 and generate an Ethernet frame. This is for inputting / outputting IP packets to be written and transmitted to the frame area 106 via the control bus 218.

The COM port is a port for transmitting and receiving commands and data via the control bus 218 between the control unit 40 on the network I / F card 215 side and the CPU 201 on the acoustic signal processing device 2 main body side. is there.
The Audio_In port and Audio_Out port are ports for inputting / outputting waveform data via the audio bus 217.

On the other hand, the frame processing unit 220 roughly includes first and second data input / output units 10 and 20, selectors 35 to 38, a control unit 40, and a word clock generation unit 41.
Among these, the control unit 40 includes a CPU, a ROM, a RAM, and the like. Take control. From the CPU 201 on the main body side that can communicate via the control bus 218, the MAC address and operation mode (master / slave, single mode only / twin mode possible) of the acoustic signal processing device 2 necessary for the operation of the network I / F card 215 Etc.) and the like.
And the control part 40 also manages the topology table mentioned later which shows the connection order of a node.

The word clock generation unit 41 is a word clock generation unit that generates a word clock serving as a reference for timing of signal data processing in various card modules connected to the audio bus 217 and transfer of waveform data in the audio bus 217. .
In the master node, the word clock generation unit 41 generates a word clock at a timing unique to the network I / F card 215 or synchronized with a word clock from another card supplied via the audio bus 217. Although the clock is also used as a reference for the transmission timing of the TL frame 100, in the slave node, the word clock generation unit 42 generates a word clock based on the reception timing of the TL frame.

  Each of the first and second data input / output units 10 and 20 operates based on an operation clock generated by an operation clock generation unit (not shown), and performs a desired operation from the TL frame 100 received by the corresponding reception I / F. It functions as reading means for reading data and writing means for writing desired data to the received TL frame 100. Also, it has a function of directly transmitting / receiving the ITL frame 110 (without writing to the TL frame 100) to / from a node for which a transmission path for circulating the TL frame 100 is not established. Since the functions of the first and second data input / output units 10 and 20 are the same, the first data input / output unit 10 will be described as a representative.

  The first data input / output unit 10 includes a TL frame reception unit 11, a waveform data reception buffer 12, a TL data reception buffer 13, a MAC processing unit 14, a delay buffer 15, a waveform data transmission buffer 16, a TL data transmission buffer 17, and a TL. A frame transmission unit 18, an ITL frame reception unit 51, an ITL data reception buffer 52, an ITL data transmission buffer 53, and an ITL frame transmission unit 54 are provided. Of these, each transmitting / receiving unit and each buffer basically operate in a FIFO (first-in first-out) format in which data written first is read first.

  Among these, the TL frame receiving unit 11 has a function of reading data from the received TL frame 100 and storing the TL frame 100 in the delay buffer 15. The ITL frame receiving unit 51 receives the received TL frame 100. It has a function of reading data from the ITL frame 110.

Then, the TL frame receiving unit 11 and the ITL frame receiving unit 51 receive the supply of the network clock NC1 extracted as the carrier by the first reception I / F 31, and synchronize with the data from the first reception I / F 31. Receive. However, the TL frame reception unit 11 receives data from the first reception I / F only when the selector 35 selects the first reception I / F side.

  The frame received by the first reception I / F 31 is related to which frame can be known by referring to the frame type data in each frame described with reference to FIGS. 11 and the ITL frame receiving unit 51 should just discard the frames other than the frames to be processed by themselves. In particular, the ITL frame receiving unit 51 receives data of all frames, but discards frames other than the ITL frames 110 and 120 without any particular processing.

Here, the function of the first data input / output unit 10 related to transmission / reception of the ITL frame 110 will be described first.
When the ITL frame reception unit 51 receives the ITL frame 110, the ITL frame reception unit 51 writes the data in the ITL data reception buffer 52. Then, it is confirmed that there is no error in the frame and output to the control unit 40. The control unit 40 performs processing according to the contents of the command described in the frame (including processing for transferring a command not addressed to the own device). Do.

The ITL data transmission buffer 53 is a buffer for storing data of the ITL frame 110 to be transmitted to the node connected to the second transmission I / F 32, and the control unit 40 performs the writing.
When the selector 36 selects the ITL frame transmission unit 54 side, the ITL frame transmission unit 54 reads the ITL frame 110 stored in the ITL data transmission buffer 53 at an appropriate timing, and the second transmission I / F32 is supplied and transmitted to the connection destination node. When the selector 36 selects the TL frame transmission unit 18 side, the transmission of the ITL frame 110 stored in the ITL data transmission buffer 53 is performed by the TL frame transmission unit 18. No action is taken.

The transmission / reception of the ITL frame 110 by the ITL frame reception unit 51 and the ITL frame transmission unit 54 is performed in units of frames without being divided into blocks.
With the function of each unit described above, the network I / F card 215 can perform communication with an adjacent node using the ITL frame 110 through a transmission path directed to the right in the drawing. The second data input / output unit 20 is used when communication is performed on the left transmission path in the figure.

Next, functions of the first data input / output unit 10 relating to transmission / reception of the TL frame 100 will be described.
First, when receiving the data of the TL frame 100, the TL frame receiving unit 11 writes the waveform data of the transmission channel to be read out of the data into the waveform data receiving buffer 12, and the data in the ITL frame area 107 is stored in the ITL data receiving buffer. 52 has a function of writing data and management data of the Ethernet frame area 106 to be written to and read into the TL data reception buffer 13.
When a data error or the like is detected, data may not be written to each of these buffers or the data once written may be changed. This will be described later.

Further, the TL frame receiving unit 11 has a function of writing all the data of the received TL frame 100 to the delay buffer 15 as it is.
Then, the waveform data of each transmission channel written in the waveform data reception buffer 12 is output sample by sample to the AUDIO_Out port of the upper layer I / F 70 in synchronization with the word clock, and is transmitted to the other data via the audio bus 217. Transmitted to the card.
The data written in the ITL data reception buffer 52 is output to the control unit 40 when one ITL frame is prepared, and the control unit 40 performs processing according to the contents of the command described in the frame ( Including processing to transfer commands not addressed to the device itself).

  The data written to the TL data reception buffer 13 is output to the MAC processing unit 14 when one Ethernet frame is prepared for the data of the Ethernet frame. Then, for the Ethernet frame confirmed that the MAC processing unit 14 is addressed to its own device, the MAC processing unit 14 extracts the IP packet from the Ethernet frame and outputs it to the IP_Packet port of the upper layer I / F 70, and the control bus 218 To the CPU 201 on the main body side. Data other than the Ethernet frame, such as meter data, is passed to the control unit 40 via the MAC processing unit 14, and the control unit 40 passes the COM port of the upper layer I / F 70 to the CPU 201 on the main body side as necessary. hand over.

  For the waveform data, the control unit 40 knows at least which transmission channel data is to be read, and the byte in the TL frame 100 is determined by calculation. The unit 40 may instruct the position to the TL frame receiving unit 11 so that only the data at the position is written in the waveform data receiving buffer 12.

Since the ITL frame area 107, the Ethernet frame area 106, and the management data are described at fixed positions in the TL frame, the TL frame receiving unit 11 reads the data from the positions once and then the control unit 40 or data to be output to the MAC processing unit 14 may be appropriately selected and written to the ITL data reception buffer 52 or the TL data reception buffer 13. Alternatively, the TL frame reception unit 11 may simply write all the data in the corresponding area to the reception buffer, and the control unit 40 may select the data.
The selection method will be described later.

  On the other hand, the waveform data transmission buffer 16 is a buffer for storing the waveform data to be output described in the TL frame 100, and the upper layer I / F 70 samples the waveform data to be output supplied from the audio bus 217. Output from the Audio_IN port at every cycle and write to the waveform data transmission buffer 16. It is of course possible to write waveform data for a plurality of transmission channels, and data to be written in bytes close to the head of the TL frame may be written in the waveform data transmission buffer 16 first. When the second data input / output unit 20 is also used for reading and writing waveform data, the upper layer I / F 70 writes waveform data to be output to the waveform data transmission buffer 26, but the waveform data transmission buffer It is of course possible to write different waveform data in 16 and the waveform data transmission buffer 26.

The TL data transmission buffer 17 is a buffer for storing Ethernet frame data and management data to be described and output in the TL frame, and the MAC processing unit 14 is output from the IP_Packet port of the upper layer I / F 70. The Ethernet frame generated based on the IP packet to be transmitted and the control data to be output supplied from the control unit 40 are written in the TL data transmission buffer 17.
Further, as described in the description of the transmission / reception of the ITL frame 110, the control unit 40 writes the data of the ITL frame 110 to be transmitted to the node connected to the second transmission I / F 32 in the ITL data transmission buffer. .

  When the own device is a slave node, when a predetermined amount (first predetermined amount) of data of the TL frame 100 is accumulated in the delay buffer 15, the TL frame transmission unit 18 accumulates the data as the accumulation proceeds. The read TL frames 100 are sequentially read from the top and stored in a buffer included in the TL frame 100. Then, as the accumulation proceeds, the data in the waveform data transmission buffer 16, the TL data transmission buffer 17, and the ITL data transmission buffer 53 are written to appropriate addresses, and the contents of the TL frame 100 are rewritten. This rewriting is preferably performed in order from the beginning of the frame so as to be in time for transmission timing described later.

Which data should be written in which byte of the TL frame 100 is calculated based on the transmission channel to be written by the control circuit 40 for the waveform data, and is instructed to the TL frame transmission unit 18. In addition, Ethernet frames, ITL frames, and the like are automatically determined for each data type according to the classification shown in FIG.
Further, instead of detecting a predetermined amount of accumulation in the delay buffer 15 and using it as a trigger for reading and rewriting by the TL frame transmission unit 18, the elapse of a predetermined time after the start of capturing the TL frame 100 is detected. , It may be triggered.

  When the own device is a slave node, when the second predetermined amount of data of the TL frame 100 is accumulated in the buffer of the TL frame transmission unit 18, the TL frame transmission unit 18 outputs the output of the TL frame after rewriting. The TL frame 100 that is started and replaced by the TL frame transmission unit 18 is output from the second transmission I / F 32 to the adjacent node if the selector 36 selects the output line from the TL frame transmission unit 18. Is done. At this time, the operation clock of the first data input / output unit 10 is supplied as it is to the second transmission I / F 32 as the network clock NC2, and the second transmission I / F converts the data of the TL frame into the network clock NC2. Are sequentially modulated as carriers and output to the communication cable CB.

Instead of detecting the second predetermined amount of accumulation and using it as a trigger for transmission, detection of the elapse of a predetermined time from the start of capturing the TL frame 100 and starting transmission using that as a trigger It may be.
As described with reference to FIGS. 2 and 3, when the Ethernet frame or the ITL frame 110 is written in the TL frame 100 and transmitted, the data is divided into a plurality of (or even one) blocks. This division and generation of a block number and the like for each block is performed by the TL frame transmission unit 18, and block data to be used for rewriting is prepared before the data rewriting timing of the TL frame 100.

  In this embodiment, the TL frame transmission unit 18 rewrites the contents and outputs the TL frame 100 stored in the delay buffer 15 at the same time. However, the rewriting is performed after the rewriting is performed first. You may make it output in order from the finished part.

In the present embodiment, the rewriting of the contents to the TL frame 100 stored in the buffer of the TL frame transmission unit 18 and the output of the TL frame 100 from the TL frame transmission unit 18 are performed independently. However, the rewriting and output may be performed at a time. That is, the TL frame transmission unit 18 starts reading out the TL frame 100 triggered by accumulation of a predetermined amount in the delay buffer 15 of the received TL frame 100, and the waveform data transmission buffer 16, the TL data transmission buffer 17, and the ITL data The data may be output while the content is replaced by the data in the transmission buffer 53.

  The data is replaced by data read from the delay buffer 15 when outputting each byte (or word) data of the TL frame 100, data stored in the waveform data transmission buffer 16, and TL data transmission buffer. An appropriate data may be selected and transmitted from the data stored in the data 17 and the data stored in the ITL data transmission buffer 53. In this case, unselected data among the data of the TL frame read from the delay buffer 15 is discarded. Also by this processing, the TL frame transmitting unit 18 can substantially output a TL frame overwritten with data to be output in an appropriate region of the TL frame 100 received by the TL frame receiving unit 11. .

  Further, as described above, in the single mode, each node reads / writes data other than the ITL frame area 107 only once while the transmission path makes one round of the TL frame. Accordingly, data other than the ITL frame area 107 is read / written only by one of the first and second data input / output units 10 and 20. In the data input / output unit that does not read / write data other than the ITL frame area 107, the data other than the ITL frame area 107 is simply passed through.

As will be described later, the master node updates the TL frame 100 after the reception of the entire TL frame 100 is completed, and the timing of writing data to the TL frame 100 and the TL frame 100 are updated. The transmission start timing is different from that of the slave node. However, the data write position in the TL frame 100 can be determined in the same manner as in the slave node. The management data 102 in the TL frame 100 is also rewritten. In this rewriting, data to be written in a new TL frame is written in the TL data transmission buffer 17, and this data is stored in the TL stored in the frame buffer. This can be done by overwriting the frame.
The above is the function of the first data input / output unit 10 related to transmission / reception of the TL frame 100.

By the way, as can be seen from FIG. 1A and the like, the transmission destination of the TL frame 100 received by a certain device is different from the transmission source of the TL frame 100 (FIG. 1A). Node B) and the same device as the transmission source (nodes A and C). In the former case, transmission of the TL frame 100 is performed from a transmission I / F of a different group from the reception I / F that has received the TL frame 100, and in the latter case, transmission is performed from the transmission I / F of the same group.
The selectors 35 to 38 are provided for performing such switching of transmission destinations.
Among these, the selectors 35 and 37 use the data input to the TL frame receiving units 11 and 21 as the data received by the receiving I / Fs 31 and 33 or the data output from the TL frame transmitting units 28 and 18, respectively. It is a selector that selects

On the other hand, the selectors 36 and 38 respectively select the data transmitted from the transmission I / Fs 32 and 34 as the TL frame output from the TL frame transmission units 18 and 28 or the ITL frame output from the ITL frame transmission units 54 and 64. It is a selector that selects whether to do.
Of these, the selector 36 and the selector 37 operate in conjunction with each other. When the selector 36 sends the output of the TL frame transmission unit 18 to the second transmission I / F 32, the selector 37 receives the second reception I / F. The data received in F33 is transferred to the TL frame receiving unit 21, and the TL frame can be received from the device connected to the second I / F side.

On the other hand, when the selector 37 is switched to the return line LB1 side and the output of the TL frame transmission unit 18 is passed to the TL frame reception unit 21, the TL frame 100 received by the first reception I / F 31 is the first data. The data is output from the first transmission I / F 34 through the input / output unit 10 → the return line LB1 → the second data input / output unit 20 (if the selector 38 selects the TL frame transmission unit 28 side). If) Accordingly, the received TL frame 100 is transmitted back to the transmission source.

In addition, the selector 36 switches to the ITL frame transmission unit 54 side in conjunction with the switching of the selector 37 to the folding line LB1 side. For the second I / F side device, the ITL frame 110 instead of the TL frame 100 is switched. Will be sent. On the other hand, when the second reception I / F 33 receives the ITL frame 110, this frame can be processed by the ITL frame reception unit 61.
Therefore, even in a state in which the TL frame 100 is folded, a path for performing communication using the ITL frame is secured with a device connected to a side that does not transmit the TL frame 100.

Communication via this route is a notification or command when an audio network system is assembled in the initial process, such as a connection detection command, a connection request command, and a response to the response described later, or a process related to a system configuration change is performed. Used for transmission and reception.
Although the selectors 36 and 37 have been described here, the selectors 38 and 35 have similar functions by operating in conjunction with each other. Then, it is possible to switch whether or not the TL frame 100 received from the second reception I / F 33 is to be looped back.

  In summary, in the acoustic signal processing device 2, the network I / F card 215 shown in FIG. 8 depends on the connection state of each node in the audio network system to which it belongs and whether its own device is a master node or a slave node. By performing the above-described processing, the hardware can realize the function related to the transmission of the TL frame and data as described with reference to FIGS.

2. 2.1 Formation of Audio Network System and Configuration Change 2.1 Communication Mode of Each Device Next, for construction and configuration change of the audio network system executed by the CPU of the control unit 40 in the acoustic signal processing device 2 shown in FIG. Related processing will be described.
In the acoustic signal processing device 2 shown in FIG. 7, the network I / F card 215 is in a state where both the selectors 35 and 37 have selected the return line side at the time of activation. In this state, the network I / F card 215 does not form an audio network system that circulates TL frames between a plurality of nodes, and is in a state in which communication with the outside is performed using ITL frames (this state is referred to as “initial communication”). (Referred to as (ITL) mode).

  After that, when it is detected that the transmission / reception I / F is connected to another device having the same network I / F card 215 and capable of forming the audio network system 1, the selector on the connected side is received. Switching to the I / F side, a ring-shaped transmission path for circulating the TL frame 100 is formed with the connected apparatus. At this point, each device forming the ring-shaped transmission path starts to function as a series of systems.

  However, in this state, the waveform data is not yet read / written from / to the TL frame 100, but data other than the waveform data such as the Ethernet frame, the ITL frame, and the management data is described in the TL frame 100 and transmitted / received between the devices. Yes (this state is called “Temporary Communication (TTL) Mode”). In this TTL mode, when a new device is connected to a side having a free transmission / reception I / F among devices located at the end of the transmission path, the newly connected device can be incorporated into the transmission path. .

  After that, when any device is designated as the master node, a ring-shaped transmission path is formed again between the devices connected at that time, and all data including waveform data is described in the TL frame. Thus, the audio network system 1 for transmission between the respective devices (nodes) is formed (this state is referred to as “voice transmission (RTL) mode”). Even in this RTL mode, when a new device is connected to a side having a free transmission / reception I / F among devices located at the end of the transmission path, the newly connected device can be incorporated into the transmission path. .

  A device including the network I / F card 215 constructs the audio network system 1 or changes the configuration according to the connection state of each device by fluidly transitioning between these ITL mode, TTL mode, and RTL mode. You can do it. In the following, processing for changing the system configuration and configuration will be described.

2.2 Operation at the System Formation Stage Next, processing related to construction and configuration change of the audio network system executed by the CPU of the control unit 40 in the acoustic signal processing device 2 shown in FIG. 7 will be described.
FIG. 9 is a flowchart of processing related to system construction that is executed by the CPU of the control unit 40 when the power is turned on and reset. This process is performed independently for each pair of transmission / reception I / Fs. For example, in the case of the network I / F card 215 shown in FIG. Process. In the following description, when the transmission I / F and the reception I / F are simply referred to, the I / F corresponding to the process being executed is indicated.
Further, when the power is turned on, the CPU of the control unit 40 performs a process of acquiring information related to the setting of the MAC address and operation mode of the own machine from the CPU 201 on the main body side separately from this process.

  The CPU of the control unit 40 starts the process shown in the flowchart of FIG. 9 when at least the MAC address of its own device can be acquired at power-on and reset. First, the request side operation of the physical connection confirmation process shown in FIG. 10 is executed to confirm whether or not a device having the capability of forming the audio network system 1 is physically connected to the transmission / reception I / F (S11). ).

FIG. 10 shows a flowchart of the physical connection confirmation process.
As shown in this figure, in the request side operation of the physical connection confirmation process executed in step S11 of FIG. 9, the CPU of the control unit 40 first outputs an ITL frame of a connection detection (AS) command from the transmission I / F. To do. If any device is connected to the transmission I / F, the AS command is received by the device.

If the received device also includes the network I / F card 215, the CPU of the control unit 40 starts the processing shown in the response side operation flowchart of FIG.
In this process, the CPU of the control unit 40 of the responding apparatus generates an AS response that is a response to the received AS command, and returns it to the AS command transmission source apparatus as a response ITL frame (S45). The information described in this response is determined in steps S41 to S44. If the MAC address of the own device can be grasped, the MAC address is described (S41, S42), and the own device is in the TTL mode or the RTL mode. If it has already participated in the system, the network ID of the system and the node ID of its own device in the system are also described (S43, S44).

  The network ID is “0” in the case of the TTL mode and a value unique to the system in the case of the RTL mode. In addition, when not participating in the system, a code indicating “undefined value” as the network ID may be described in the AS response. The node ID is an ID for identifying a specific node in the system, and the value is a value unique to each node in the system.

  On the other hand, the apparatus that has transmitted the AS command waits while monitoring reception of the AS response. Then, when an AS response is received before a predetermined time elapses (S32), it is understood that a device capable of forming the audio network system 1 is connected to the transmission / reception I / F. Therefore, the contents of the topology table are updated based on the contents of the received AS response (S33). The topology table is a table for registering the connection order of each device connected directly to the own device or indirectly through another device.

FIG. 11 shows an example of this topology table.
As shown in this figure, in the topology table, what devices are connected to the backward side and the forward side of the own device in what order are registered by the network ID, node ID, and MAC address. . Among these, the MAC address is unique to the device, but the network ID and node ID are variable according to the participation status in the system. Further, the model ID of the device and a frame transmission delay time between devices (or a distance between devices) described later may be registered in the topology table.

  In the topology table, for the backward side and the forward side, the top column in the figure shows information on devices directly connected to the own device, and the next column is the top column. It shows the information of the device connected to one device ahead of the device described in, and so on.

Which of the two sets of transmission / reception I / Fs is connected to the forward side may be arbitrarily determined based on the ID of the I / F at the time of activation. Moreover, even if the different direction is recognized as the forward side depending on the device, there is no particular problem because the relative positional relationship between the devices can be grasped. However, once the mode is shifted to the TTL mode or the RTL mode, as described in the explanation of FIG. 4, the side that first transmits a TL frame that makes a round is unified to the forward side as seen from the master node.
Or, when the direction is fixed such that the first transmission / reception I / F is the backward side and the second transmission / reception I / F is the forward side, and the forward side and the backward side are connected between the devices. May be an error. This reduces the degree of freedom of connection by the user, but the system is easy to control.

Returning to the description of FIG. 10, after step S33, the CPU of the control unit 40 transmits / receives an ITL frame to / from the response side apparatus as appropriate, and transmits the contents of the topology table to the response side apparatus (S34). . Specifically, the data of the device connected to the side opposite to the response side device is transmitted including the connection order information, and the information is registered in the topology table of the response side device.
Thereafter, an ITL frame for a table update notification that conveys information on the response side device is generated and transmitted from the transmission I / F on the opposite side to the AS response reception side (S35), and the processing of FIG. The process proceeds to step S12 of step 9.

Although not shown, the device that has received this table update notification registers the data of the notified responding device in its own node table. Also, if a device is connected to the side opposite to the side that received the table transmission notification, the table update notification ITL frame that conveys information of the response side device is also transmitted to that device. In this way, the data of the response side device is registered in the node table in all devices connected to the opposite side of the response side device as viewed from the request side device that has performed the processing of FIG.
However, the request side operation itself may be terminated when the transmission in step S35 is completed.

Further, when a time-out occurs in step S32, it is understood that no device is connected to the transmission I / F, or even if the device is connected, the device is not capable of forming the audio network system 1. The process of FIG. 10 is terminated, and the process proceeds to the process of step S12 of FIG.
If it is clear that the device is not connected to the transmission / reception I / F, for example, the reception I / F cannot detect the network clock at the time of step S31, the AS command is not transmitted, and step S32 is not performed. This determination may be NO.

When the process of FIG. 10 is completed, the CPU of the control unit 40 determines whether or not the connection of a device capable of forming the audio network system 1 in the transmission / reception I / F is confirmed in the physical connection confirmation process in step S12 of FIG. (Y / N in step S32) is determined.
If the connection is not confirmed, the process returns to step S11 and the physical connection confirmation process is performed again (may be after waiting for a predetermined time). If the connection is confirmed, the logical connection preparation process shown in FIG. In step S13, it is determined how the TTL mode or RTL mode system can be formed with the partner apparatus whose connection has been confirmed.

  In general, the logical connection preparation process refers to the network IDs of the own device and the partner device, and assigns a low priority device to a high priority device with a priority of RTL> TTL> ITL. Is a process for determining to be incorporated into a participating system. In addition, logical connection means forming a common transmission path for circulating TL frames between apparatuses, or adding a new apparatus to an existing transmission path.

FIG. 12 shows a flowchart of the logical connection preparation process.
As shown in this figure, in the logical connection preparation process, the CPU of the control unit 40 first determines which mode is RTL, TTL, or ITL based on the network ID of the own device (S51). .

In the case of the ITL mode or the TTL mode, next, the network ID of the partner device is confirmed, and it is determined which mode the partner device is in RTL, TTL, or ITL (S52). Here, in the case of the RTL mode, since it is understood that the own device is a mode having a lower priority, it is determined that the own device is incorporated into the RTL mode system in which the partner device participates.
If the own apparatus is in the ITL mode, it can be incorporated into the system as it is, and therefore, in the logical connection establishment process in step S19 in FIG. .

If the device itself is in the TTL mode, the device temporarily receives a reset, and after entering the TTL mode system, enters the system in which the partner device participates, and then shifts to a state of waiting for a reset command from the partner device. Decide that. The reason for requesting a reset here is that if the nodes at the ends of two systems in which a ring-shaped transmission path is formed are connected as they are, a transmission path in which the two rings are merged is formed. This is because two TL frames exist on the transmission path at the time of connection, and frame transmission cannot be normally performed.
When the operation to be performed by the device itself is determined as described above, the process in FIG. 12 is terminated and the process proceeds to step S14 in FIG.

If the ITL mode or TTL mode is selected in step S52, the process proceeds to step S53.
When the own device is in the ITL mode (S53) and the partner device is in the TTL mode (S54), it can be seen that the own device is in a lower priority mode, so the partner device joins the own device. To be incorporated into a TTL mode system. Therefore, in the logical connection establishment process in step S19 in FIG. 9, it is determined to perform a response side operation for shifting to the TTL mode, the process in FIG. 12 is terminated, and the process proceeds to step S14 in FIG.

  If both the own device and the partner device are in the ITL mode, it is determined that the own device and the partner device form a TTL mode system. At this time, it is determined which is the temporary master node in the system. There is a need. This determination algorithm may be arbitrary, but here it is determined based on the size of the MAC address. Therefore, in this case, it is determined whether or not the MAC address of the own device is larger than the MAC address of the partner device (S55). If the own device is large, the own device is set as a provisional master (S56), and the transition to the TTL mode is led, so that in the logical connection establishment process of step S19 in FIG. It is decided to perform the operation, the process of FIG. 12 is terminated, and the process proceeds to the process of step S14 of FIG.

If the own device is small in step S55, the partner device becomes a provisional master. Therefore, in order to have the partner device incorporate it into the system, it is decided to perform a reply side operation for shifting to the TTL mode, and the processing in FIG. Then, the process proceeds to step S14 in FIG.
As an algorithm for determining the temporary master, in addition to the MAC address size, the one that has sent the AS command in the physical connection confirmation process is the temporary master, and the longer one from the power-on or reset is the temporary master. A combination of these conditions is also conceivable.

  Next, when the own device is in the TTL mode in step S53, it is determined whether or not a twin-mode transmission path is formed when the partner device is connected (S57). Specifically, it is determined whether or not the partner device is a node located at the opposite end of the system in which the partner device is participating. This determination may be made by acquiring the MAC address of the node at the opposite end from the topology table.

  In this embodiment, in view of the fact that the TTL mode is a provisional communication mode up to the transition to the RTL mode, the TTL mode permits only the single mode operation that is the basic configuration of the network. For this reason, in the case of YES in step S57, no logical connection is made with the counterpart device. Therefore, it is determined to return to the physical connection confirmation process, the process of FIG. 12 is terminated, and the process proceeds to step S14 of FIG. In this case, even if the logical connection with the counterpart device is not performed, since the counterpart device participates in at least the TTL mode system, there is no possibility that a device that cannot participate in the TTL mode system may appear.

  Further, in this case, if the connection status between the devices does not change, the logical connection preparation process after the physical connection confirmation process again becomes YES in step S57, so that the process up to this point is always repeated. However, it is preferable to periodically perform physical connection confirmation processing and logical connection preparation processing so that each device can be quickly shifted to an appropriate communication mode when the connection status between the devices changes.

  If NO in step S57, if the partner apparatus is in the ITL mode (S58), it is understood that the own apparatus is in a higher priority mode, so that the partner apparatus is participating in the TTL. Decide to incorporate into the mode system. Therefore, in the logical connection establishment process of step S19 in FIG. 9, it is determined to perform the request side operation for shifting to the TTL mode, the process of FIG.

  Further, if the partner device is in the TTL mode (S58), it is understood that the own device and the partner device are participating in different TTL mode systems. In this case, one of the devices is temporarily removed from the system, and the device is incorporated into a system in which the other device participates (in this case, the system on the side from which the device has been detached is And then it will be demolished).

In this case, either device may be detached, but here, as in the case of step S55, the determination is made based on the size of the MAC addresses of the connected devices (S59). Therefore, if the MAC address of the own device is larger than the MAC address of the partner device, an ITL frame of a reset instruction command is transmitted to the partner device to cause the partner device to leave the system (S60). Further, since the counterpart device returns to the ITL mode as described later by resetting, it is determined to restart the processing from the physical connection confirmation processing, the processing in FIG. 12 is terminated, and the processing proceeds to step S14 in FIG.
In this case, if the connection status between the devices does not change, the process proceeds to the lower side in step S58 in the logical connection preparation process after the physical connection confirmation process again.

Also, if the own device is small in step S60, in order to disassemble the system in which the own device participates in the counterpart device, it is decided to wait for a reset command from the counterpart device, and the processing of FIG. The process proceeds to S14.
In the case of step S60, in addition to the algorithm exemplified in the description of step S55, an algorithm of disassembling the one having fewer nodes can be employed.

  In addition, when the own device is in the RTL mode in step S51, if the partner device is in the ITL mode (S61), it can be seen that the own device is the higher priority mode, so Decide to incorporate into a participating RTL mode system. Therefore, in the logical connection establishment process of step S19 in FIG. 9, it is determined to perform the request side operation for shifting to the RTL mode, the process of FIG. 12 is terminated, and the process proceeds to the process of step S14 in FIG.

  Even when the partner device is in the TTL mode in step S61, it can be seen that the own device is a higher priority mode, so that the partner device is incorporated into the RTL mode system in which the own device participates. decide. However, in this case, since it is necessary to incorporate the partner apparatus after leaving the partner system once participating, an ITL frame of a reset instruction command is transmitted to the partner apparatus (S62). Further, since the counterpart device returns to the ITL mode as described later by resetting, it is determined to restart the processing from the physical connection confirmation processing, the processing in FIG. 12 is terminated, and the processing proceeds to step S14 in FIG. In this case, if the connection status between the devices does not change, the logical connection preparation process after the physical connection confirmation process again proceeds to the left side in step S61.

  If the counterpart device is in the RTL mode in step S61, basically, no logical connection is established with the counterpart device. In the present embodiment, the RTL mode is a mode in which the audio network system 1 is actually used for acoustic signal processing, and the RTL mode system is broken without an explicit intention from the user. This is because the RTL mode systems are not connected to each other (addition of a device to the system itself is allowed).

However, if the device is connected to the device on the opposite end of the system in which the device participates, the connection mode changes from cascade connection to loop connection, so the operation mode is changed from single mode to twin mode. It can be considered to shift to the mode. In the case of the RTL mode, whether or not to permit this transition is determined by the mode setting made in the master node as described in the explanation of FIG.

  Therefore, if the partner device and the network ID match and the twin mode permission is set (S63), the shift to the twin mode is determined. In this case, there is a problem as to which of the own device and the partner device has the initiative in the logical connection process. Here, the initiative is given to the device located on the backward side. Therefore, according to the determination result in step S64, it is determined in the logical connection establishment processing in step S19 in FIG. 9 that the request side operation or the response side operation is performed for the twin RTL mode transition, and the processing in FIG. The process ends, and the process proceeds to step S14 in FIG.

  In addition, NO is determined in step S63 because (a) when the network ID is different from the counterpart device, that is, when different RTL mode systems are connected, or (b) operation in the twin mode is not permitted. Is the case. In any of these cases, since no logical connection is made with the counterpart device, it is decided to return to the physical connection confirmation process, the process of FIG. 12 is terminated, and the process proceeds to the process of step S14 of FIG. .

  Further, in this case, if the connection status between the devices does not change, the logical connection preparation process after the physical connection confirmation process again becomes NO in step S63, so that the processes up to this point are always repeated. However, it is preferable to perform the process periodically as in the case of YES in step S57.

Returning to the description of FIG. 9 again.
When the logical connection preparation process shown in FIG. 12 ends, the process to be executed next proceeds to step S14 in FIG. 9 in a state where the logical connection process, waiting for reset, or physical connection process is determined. .
If the determined process is a physical connection process, NO is returned in steps S14 and S21, and the process returns to step S11 to repeat the process.

  In the case of waiting for a reset, the process proceeds from step S21 to S22, waits for a predetermined time, and waits for a reset request from the counterpart device. Here, the process shown in FIG. 9 is started also at the partner apparatus side when the power is turned on or reset. In the logical connection preparation process, if the relationship between the own device and the partner device is “reset waiting”, the partner device performs a reset instruction in step S60 or S62 in the logical connection preparation process executed by the partner device. A command ITL frame should be sent.

Here, FIG. 13 shows a flowchart of processing executed by the CPU of the control unit 40 when this reset instruction is received. This process is executed independently of other processes by interruption.
Then, when receiving the reset instruction, the CPU of the control unit 40 first resets its own device (S71). This process includes a process of switching the selectors 35 to 38 on both sides to the return line / ITL frame transmitting unit side, returning itself to the ITL mode, and initializing the topology table and the network ID. However, it is not necessary to delete the MAC address, master / slave, twin permission / denial, and double / duplex settings.

After the above, an ITL frame of a reset response indicating completion of reset is transmitted to the reset instruction source (S72), and an ITL of a reset instruction command is transmitted from the transmission I / F on the opposite side to the side receiving the reset instruction to the adjacent node. The frame is transmitted (S73), and the process ends.
Note that the CPU of the control unit 40 stops the processing of FIG. 9 that has been performed until the reset in step S71. Then, the process shown in FIG. 9 is started again in response to the reset. However, if there is a reset instruction from another device, it may be possible to continue to receive a connection request command or the like. Therefore, it is possible to wait for a predetermined time before starting the processing shown in FIG.
Conversely, a device that has transmitted a reset instruction command to the counterpart device may start the next physical connection confirmation process triggered by reception of a reset response from the counterpart device. This is because at this point, the counterpart device has returned to the ITL mode and can be expected to be incorporated into the system.

  Further, as is clear from step S73 of FIG. 13, when the device at the end of a certain system is reset, all devices participating in the system are sequentially reset, return to ITL mode, and can participate in another system. It becomes a state. When joining systems operating in TTL mode, or when a system operating in TTL mode is absorbed by a system operating in RTL mode, it participates in the system that is absorbed by reset in this way. All the devices that are in use are once returned to the ITL mode.

  Although not shown, the device that has received the reset response deletes the information of the device that performed the reset and the device connected to the device from the node table of the device itself. Further, this deletion is also transmitted to the device connected to the opposite side, and the information of the device that has been reset and the device that was connected to that device are deleted sequentially.

Returning to the description of FIG. 9 again.
In the logical connection preparation process of step S13, when it is determined to execute the logical connection establishment process, the process proceeds from step S14 to S15. When the logical connection establishment process is executed as the requesting side, it is determined whether or not there is no problem in the transmission of the TL frame even if the partner apparatus is incorporated in the system in which the own apparatus participates (S16 to S18). . Here, this determination is made based on the number of nodes and the total distance of the frame transmission path.

  Of these, the number of nodes can be easily grasped by referring to the topology table, and if the counterpart device is incorporated within the predetermined number, there is no problem. However, when shifting to the twin mode, it is necessary to note that the number of nodes does not increase due to the connection because the connection is made with a node already participating in the system.

  For the total distance of the frame transmission path, first, the distance between the own device and the partner device is measured. This measurement is performed by sending an ITL frame for distance measurement (in the format shown in FIG. 4 (b)) to the counterpart device, and then returning the response ITL frame immediately after receiving it (here) Can also be performed by measuring the time taken to receive the data in the format shown in FIG. The time required for the partner device to receive the ITL frame for distance measurement and transmit the response ITL frame is considered to be constant for each type and version of the network I / F card 215. Therefore, the time obtained by subtracting the certain time is a time proportional to the distance between the devices. The measurement should be performed several times, and the maximum value among the values that can be considered stable should be adopted. Further, during this measurement, in order to prevent errors, it is preferable not to transmit / receive other ITL frames such as AS commands.

  And when each device participates in the system, be sure to perform this distance measurement and record the distance between adjacent devices in the topology table, etc. The total distance of the frame transmission path can be obtained. If this total distance falls within a predetermined value, there is no problem.

  However, when the system is operating in the twin mode, if the connection is cut or the node is stopped somewhere in the system, the return path of the transmission path is set on both sides, and one ring shape is formed by combining two rings. A transmission path is formed and the operation returns to the single mode. In this case, in general, the transmission path after returning to the single mode is longer than the transmission path in the twin mode.

Therefore, when operating in the twin mode, not only when the partner device is incorporated in the transmission path that is currently used, but also in which part the connection is disconnected or the node is stopped and the operation returns to the single mode. However, there is no problem when the total distance of the transmission path after returning is within a predetermined value.
If there is no problem in both the number of nodes and the total distance, the process proceeds from step S18 to S19, and logical connection establishment processing is executed. If there is a problem, the partner apparatus cannot be incorporated into the system, so the process returns from step S18 to step S11 and the process is repeated. At this time, a notification that it cannot be incorporated may be transmitted.

Note that one of the reasons for setting the criteria of steps S16 and S17 is that if the number of nodes is large or the total distance of the transmission path is long, the time required to make one round of the transmission path in the TL frame increases. This is because the TL frame transmitted from the master node cannot be returned to the master node by the timing necessary for generating the TL frame in the later cycle.
Therefore, considering this point,
(Permissible time for frame transmission delay determined according to period update amount k)
-(Transmission delay time per node) x (number of nodes)
> (Transmission delay time depending on the total distance of the transmission path)
If so, it may be determined that there is no problem in step S18.
Also, the frame transmission delay allowable time determined according to the period update amount k is shorter than the k sampling period by the required time α, which is the time required for preparation of a new TL frame in the master node. Therefore, if k is increased, the allowable time can be increased.
Therefore, when the number of nodes and the total distance of the transmission path do not satisfy the above condition, it is possible to satisfy the condition by increasing k.

Next, FIG. 14 shows a flowchart of the logical connection establishment process executed in step S19 of FIG.
This process is a process in which a device performing a request side operation finally confirms that a device performing a response side operation can be incorporated into a system in which the device itself participates, and executes this incorporation. The reply side operation is basically a passive process, and performs a process according to a command received from a device that performs the request side operation. Further, in the logical connection preparation process, when the relationship between the own device and the partner device is a “response side operation”, the partner device performs the logical connection preparation process in the logical connection preparation process executed by the partner device. A decision to perform "request side action" should be made.

In this logical connection establishment process, the requesting device first transmits an ITL frame of a connection request (CQ) command for finally confirming that the partner device (response device) can be incorporated into the system. Output from the I / F (S81). In this CQ command, information indicating in which mode system (RTL / TTL and single / twin) the partner device is incorporated is described, and the partner device is prepared for communication in that mode. Good.

Then, when the counterpart device receives the CQ command, the CPU of the control circuit 40 indicates CQ indicating any of the states of logical connection preparation, RTL operation, TTL operation, and connection possible depending on the status of the own device. The response ITL frame is returned to the source of the CQ command (S101).
Here, since it is confirmed in the logical connection preparation process that the counterpart device is ready to be incorporated into the system, the response should basically be “connectable”. However, when another device is also connected to the opposite side as seen from the counterpart device, while the subject device performs the processing of steps S14 to S18, due to a request from the opposite device, It is possible that it has been incorporated into the system on that side, or preparation for incorporation has progressed.

  Responses other than the above “connection possible” are made in such a case. “Preparing for logical connection” indicates a state in which a CQ command is received from another device and then a reception of a communication mode switching instruction (TM) command is awaited. “RTL in operation” and “TTL in operation” indicate that the RTL mode system or the TTL mode system has already been incorporated.

  On the other hand, the device that has transmitted the CQ command waits while monitoring the reception of the CQ response. Here, when a predetermined time elapses or a time-out occurs or a CQ response indicating that the logical connection is being prepared is received (S82), retry is performed up to a predetermined number of times (S88, S89). However, if the content still does not change, it is decided that the incorporation into the system is given up and the process returns to the physical connection confirmation process this time, and the process of FIG. 14 is terminated. In the case of a response timeout, there is no need to wait for a predetermined time in step S89.

If a CQ response indicating that the RTL operation is in progress is received (S83), since the partner apparatus cannot be incorporated into the system, it is determined to return to the physical connection confirmation process, and the process of FIG. 14 is terminated.
If a CQ response indicating that the TTL is operating is received (S84), if the own device is participating in the RTL mode system or if the own device has a larger MAC address than the other device (the TTL mode systems ( S90 ), an ITL frame of a reset instruction command is transmitted to the partner device ( S91 ). Then, it is determined to return to the physical connection confirmation process in order to perform the process again from the beginning and incorporate the partner apparatus into the system, and the process of FIG. 14 is terminated. If NO in step S90, since the partner device cannot be incorporated into the system, it is determined to simply return to the physical connection confirmation processing, and the processing in FIG. 14 ends.

  On the other hand, when a CQ response indicating that connection is possible is received, the determinations in steps S82 to S84 are all NO. Then, a communication mode switching instruction (TM) command that finally requests the counterpart device to change the operation mode is transmitted from the transmission I / F (S85). The TM command describes in which mode (RTL / TTL and single / twin) the partner device is to be transferred, and information on the network ID of the system in which the partner device is incorporated.

  When the counterpart device receives the TM command, the CPU of the control circuit 40 first transmits an ITL frame of a TM response indicating the completion of the transition to the source of the TM command (S103). Then, immediately after that, the loopback of the TL frame is canceled for the side receiving the TM command (S104). This release may be performed by switching the two selectors on the release side to the reception I / F side and the TL frame transmission unit side, respectively.

  Since the device newly incorporated in the system has not yet transmitted / received the TL frame, there is no problem even if the loopback is canceled at any timing. In addition, regardless of the mode, the loopback is canceled in the same way. However, if the loopback is canceled, the ITL frame cannot be directly transmitted on the canceled side (however, it can be transmitted if it is written in the TL frame). Therefore, the TM response is transmitted before the loopback is canceled. Go to.

  After step S104, the CPU changes its operation mode and network ID according to the designation of the TM command (S105), and notifies the upper layer (main body side CPU) of the completion of mode transition (S106). The process ends. At the time of step S105, depending on the operation mode and the system configuration, the waveform data and the Ethernet frame are read from and written to the TL frame using either (or both) of the first and second data input / output units 10 and 20. Whether or not to read / write the waveform data with respect to the TL frame is set.

On the other hand, if the requesting device receives a TM response from the partner device before the time-out after sending the TM command (S86), the requesting device switches the selector at the timing when the TL frame is not transmitted and received, and cancels the loopback on the partner device side. (S87). In a device that has already joined the system, if the loopback is canceled during transmission / reception of the TL frame, the TL frame is transmitted to another transmission destination in the middle, and the frame is broken. Therefore, it is important to cancel the loopback between frames as shown in FIG. When the requesting device makes a logical connection with another device for the first time, the TL frame has not yet been circulated at the stage of step S87. Therefore, after step S87, generation and transmission of a TL frame may be started as a master node (provisional in the case of TTL mode).
And the logical connection process of FIG. 14 is complete | finished above.

Also, if a time-out occurs in step S86, it is determined that the incorporation into the system is given up and the process returns to the physical connection confirmation process this time, and the process of FIG. 14 is terminated.
The response side device also determines that a time-out has occurred if no TM command is received within a predetermined time after the transmission of the CQ response (S102), and at this time, it quits its incorporation into the system and returns to the physical connection confirmation processing. The logical connection establishment process is terminated. The same applies when the CQ command is not received within a predetermined time after the response side operation is started.

  Returning to the description of FIG. 9 again, after the logical connection establishment process shown in FIG. 14 is completed, the process proceeds to step S20. If the connection is established in the logical connection establishment process (step S87 of the request side operation or step S104 of the response side operation is executed), the process is terminated as it is. On the other hand, if it is determined to perform physical connection again, the process returns to step S11 and the process is repeated.

  Then, in the plurality of acoustic signal processing devices 2, the CPU of the control unit 40 executes the processing described with reference to FIGS. 9 to 14, so that the power is turned on and the devices connected to the cables are automatically and sequentially. In addition, a network system that circulates TL frames in the TTL mode can be formed.

  In this state, waveform data is not yet transmitted, but the Ethernet frame and the ITL frame can be written in the TL frame and arbitrarily transmitted / received between the devices that have become nodes constituting the system. Therefore, an operation of operating a console of a certain device, transmitting the operation content to another device, and editing a parameter value in the device can be performed without any problem. Also, negotiation according to a complicated algorithm can be easily performed by transmitting and receiving IP packets using Ethernet frames.

As described above, the processing shown in FIG. 9 is performed independently for each pair of transmission / reception I / Fs. In addition, after the system is formed by a plurality of devices, the devices at both ends independently perform the transmission / reception I / F on the side performing the loopback.
Accordingly, a new device is incorporated into the system at both sides of the system at the same time, and if only one of them is incorporated, the conditions of steps S16 to S18 are satisfied. However, when both sides are incorporated, this condition is not satisfied. It can happen.
In such a case, the TL frame can be circulated by forcibly excluding the device incorporated on one side, which is determined in advance, on the forward side or the backward side from the system at the discretion of the master node. It ’s best to keep things in good condition.

By the way, the process described so far includes the process of incorporating a new device into the RTL mode system, but does not include the process of first setting the device to the RTL mode. Next, this process will be described.
In this embodiment, an operation mode switching (OM) command is prepared as a command for designating a master node, and a device that receives this command sets itself as a master node, and first sets the RTL mode. Migrate to

  Further, although it is not impeded that any device automatically determines and issues a master node, the OM command is preferably issued according to a user instruction. In this case, at least one of the devices to configure the audio network system 1 is provided with a function of accepting a master node selection from the user. As this function, referring to the topology table, a list of devices in a communicable range may be presented to the user, and a master node may be selected from the list. At this time, it is also preferable to accept the setting of the operation mode (twin permitted / not permitted, twin double / duplex, etc.).

  If an ITL frame is used, communication is possible with all devices in a range where physical connection is made, regardless of the operation mode of each device. Between devices operating in the TTL mode (also in the RTL mode), the ITL frame is described in the TL frame and transmitted. If the transmission path of the TL frame is interrupted, the ITL frame is transmitted as it is from the ITL frame transmission unit. That's fine.

  When the master node is selected by the user, the device that accepts the selection transmits an ITL frame of the OM command that describes the setting of the operation mode as a parameter with the device selected as the master node as the transmission destination. To do. This transmission is performed with reference to the topology table to the side where the transmission destination apparatus exists.

FIG. 15 shows a flowchart of processing executed by the CPU of the control unit 40 when this OM command is received.
As shown in this figure, the CPU of the control unit 40 of the device that has received the OM command first determines whether or not the received command is addressed to its own device (S111). If it is not addressed to the own apparatus, the ITL frame of the received OM command is transmitted as it is to the opposite side to the receiving side (S117), and the process is terminated. Until the OM command reaches the destination device, each device in the middle sequentially mediates transmission of the ITL frame in this way. This also applies to other commands.

  On the other hand, if it is addressed to the own device in step S111, the ITL frame of the OM response is transmitted to the side where the device exists with the transmission source device of the OM command as the transmission destination (S112). After that, as in the case of step S71 in FIG. 13, the device itself is reset, and if it is currently participating in any system, the system is temporarily removed (S113). Thereafter, the own apparatus is set as a master node (S114), and a unique network ID in the RTL mode is set in the own apparatus (S115). Thereafter, an ITL frame of a reset instruction command is transmitted to both sides (S116), and the process is terminated.

Thereafter, the devices in the communicable range starting from the devices on both sides are sequentially reset. Then, the device itself that has become the master node also starts the processing shown in FIG. 9 and, as devices participating in the RTL mode system, devices connected on both sides are sequentially incorporated into the system as long as conditions permit. Go. Note that the process shown in FIG. 9 may be triggered by reception of a reset response from an adjacent node. This is because at this point, the adjacent node has returned to the ITL mode and can be expected to be incorporated into the system.
Through the above processing, the audio network system 1 in the RTL mode capable of voice transmission can be formed by setting the master node in accordance with a user instruction.

Even after the system is formed once, if a new device is connected to both ends, the device can be incorporated into the system at any time. In addition, when the user wants to change the master node or the operation mode, the user can issue an OM command by giving an instruction at any time.
Even if the audio network system 1 is operating in the RTL mode, when any node receives the OM command addressed to itself, that node becomes a new master node, and the entire system is processed by the processing shown in FIG. The audio network system 1 is formed again after resetting.

2.3 Specific Example of System Formation Next, a specific example of a procedure for forming an audio network system by the processing described so far will be described with reference to FIGS. 16 to 20.
First, in FIG. 16 and FIG. 17, a system configuration procedure in the case where five devices A to E are connected in advance by a communication cable and the power of the device E is sequentially turned ON. An example of

First, when the devices A and B are powered on as shown in FIG. 16A, these devices start the processing shown in FIG. 9, respectively, and the AS is performed by the physical connection confirmation processing shown in FIG. By exchanging commands and AS responses, the presence of each other is recognized and information is exchanged, and each other's information is registered in the topology table (the changed portion is indicated by hatching, and so on). In the logical connection preparation process of FIG. 12, since both are in the ITL mode, with either apparatus as a temporary master node in steps S55 and S56, the logical connection establishment process of FIG. Thus, a TTL mode system can be configured.

Next, when the power of the device C is turned on as shown in (b), the device B recognizes the presence of the device C through the physical connection confirmation process, exchanges information with the device C, and stores each other information in the topology table. Register.
Thereafter, as shown in (c), device B notifies device C of information of device A already connected to the opposite side, and device A notifies information of device C newly connected to the opposite side. To do. As a result, all the devices A to C have information on all the devices that have been turned on.
Further, since the device B is in the TTL mode and the device C is in the ITL mode, the device B incorporates the device C into the system by the logical connection establishment process of FIG.

  Next, as shown in (d), when the power of the device D is turned on, as in the case of (b), the device C recognizes the presence of the device D through the physical connection confirmation process and exchanges information with the device D. And register each other's information in the topology table.

After that, as shown in FIG. 17E, the device C notifies the device D of the information of the devices B and A that are already connected to the opposite side, and the device D newly connected to the opposite side to the device B. Notify information. As shown in (f), the device B notifies the device A connected to the opposite side of the information of the device D notified from the device C. As a result of the above, all of the devices A to D have information on all the devices that have been turned on.
In addition, since the device C is in the TTL mode and the device D is in the ITL mode, the device C incorporates the device D into the system by the logical connection process of FIG.

Similarly, when the power of the device E is turned on in (g), the device D, which is the node at the end of the system, contacts the newly detected device E and is incorporated into the system. In addition, as shown in (h), the node table information is sequentially notified of information that is not grasped by each device, so that all the devices A to E have information about all the devices that have been turned on. It will be.
Through the above procedure, a network system that circulates TL frames in the TTL mode can be automatically formed by the devices A to E that are sequentially turned on. In the above example, it goes without saying that the same operation is performed even if the power supply is replaced with the cable connection.

Next, FIG. 18 shows an operation example when systems operating in the TTL mode are connected to each other.
In this figure, the devices A to C form a TTL mode system, and the devices D and E form a TTL mode system different from the devices C and D. And are newly connected by a communication cable.
In this case, since the devices C and D are regularly performing physical connection confirmation processing in step S11 of FIG. 9, the existence of each other is confirmed by this physical connection confirmation processing (a).

Then, when proceeding to the logical connection preparation process in step S13, since the devices in the TTL mode are connected, the device C having a large MAC address transmits a reset instruction command to the device D in step S60 of FIG. As a result, the device D leaves the system and returns to the ITL mode (b).

Device D also transmits a reset instruction command to device E on the opposite side of device C as part of the reset process. As a result, the device E also returns to the ITL mode (c).
On the other hand, after transmitting the reset instruction command to the device D, the device C sequentially performs the physical connection confirmation processing, the logical connection preparation processing, and the logical connection establishment processing again, and joins the device D in the ITL mode to its own participation. (D, e).

In addition, after the device D is incorporated into the system, the physical connection confirmation processing, the logical connection preparation processing, and the logical connection establishment processing are sequentially performed as a node at the end of the system, and the adjacent device E in the ITL mode is Incorporate into your participating system (e, f).
When systems operating in the TTL mode are connected to each other, one system that combines them can be automatically formed by the above procedure.

Next, FIG. 19 shows an operation example in the case where devices constituting the system operating in the TTL mode receive an operation mode switching (OM) command.
This figure shows an example in which the devices A to E form a TTL mode system and the device B receives an OM command.

In this case, the device B that has received the OM command resets itself and leaves the participating system by the processing shown in FIG. 15, sets itself as the master, and shifts to the RTL mode (a, b). ). Further, a reset instruction command is transmitted to the devices on both sides, the devices on both sides are also disconnected from the participating systems and returned to the ITL mode (c).
This reset instruction command is sequentially transmitted to all connected devices from device C to device D in (d) and from device D to device E in (e), and all devices are once returned to the ITL mode. It is.

  On the other hand, when the devices A and C complete the reset and transmit a reset response, the device B starts the process shown in FIG. Then, the physical connection confirmation process, the logical connection preparation process, and the logical connection establishment process are sequentially performed, and the adjacent devices A and C that are in the ITL mode are incorporated into the RTL mode system that has the master as the master (d, e).

  After that, the device C that is the node at the end of the system at the time of (e) sequentially performs the physical connection confirmation process, the logical connection preparation process, and the logical connection establishment process, so that the adjacent device in the ITL mode is set. Incorporate device D into its participating system (f). Then, the device D similarly incorporates the device E into its participating system (g).

  When an apparatus that constitutes a system operating in the TTL mode receives an OM command, the TTL mode system can be replaced with the RTL mode system by the above procedure. Note that the operation of each device is the same even when a device constituting the system operating in the RTL mode receives an OM command.

Next, FIG. 20 shows an example of the transition operation from the single mode to the twin mode.
This figure shows an example in which devices C and D at both ends are connected by a cable in a system operating in the RTL mode where devices D → E → A → B → C are connected in this order. ing. However, transition to twin mode is allowed.

In this case, the devices C and D are in a state in which physical connection confirmation processing is periodically performed in step S11 of FIG. (A, b). In the topology table, each other's information is registered as information on the opposite end node, but in addition to this, it is also registered as a newly connected node (b). At this time, the devices C and D can grasp that the physical connection is made in a loop .

Further, in the case of cascade connection, the devices C and D notify the information of the newly connected device to the device connected to the opposite side of the device. However, if this is done in the case of a loop connection, the notification issued by the device C and the notification issued by the device D overlap, and since there is no end to the connection, it is not clear where to stop the notification. .

Therefore, in the case of loop connection, only the forward-side device notifies the newly connected device information to the device connected to the opposite side of the device. Also, each device that has received this notification, when determining that it is a notification that its own device has been added, will not notify further.

In the example of the figure, the device D notifies the device E on the opposite side that the device C has been added, and the notification is sequentially transmitted in the order of devices E → A → B → C. However, since the device C determines that this notification is a notification that the own device has been added, and this indicates that the notification has made one round of the system, the transmission of the notification ends here.
Through the above processing, each device can grasp that the forward (formal) end and the backward (formal) end are the same device, that is, that the connection is in a ring shape. (C)

For device C, in the logical connection preparation process, the determination in step S64 in FIG. The frame transmission path changes to two ring-shaped paths, and a twin mode connection is established.
In a system operating in the RTL mode, when the devices at both ends are connected by a cable, the operation can be shifted to the twin mode operation by the above processing.

2.4 Operation when Transmission Path is Disconnected Next, an operation when disconnection between nodes occurs in an audio network system operating in the RTL mode or the TTL mode will be described.
In the audio network system operating in the RTL mode or the TTL mode, when each node detects that the connection with the adjacent node is disconnected, the node that detects the disconnection returns the selector on the return line / ITL frame transmission unit. Switch to the side, and set the loopback of the transmission path of the TL frame to the side that detected the disconnection.

Even if a TL frame is transmitted to an adjacent node in a state in which the connection with the adjacent node is disconnected, the TL frame is simply lost, so that the node beyond the disconnected connection is removed from the system. This is because the TL frame circulation is continued by forming a new transmission path only with the remaining nodes.
21 and 22 below show an example in which a disconnection occurs in the system in the RTL mode, but in the TTL mode, the same operation is performed by replacing RTL with TTL.

FIG. 21 shows an example of a system configuration change procedure at the time of disconnection.
This figure shows an example in which the connection between the device D and the device E is cut off in a state where the RTL mode audio network system is formed by the six devices A to F. . For disconnection of the connection, in addition to the case where the communication cable itself is physically disconnected, when the communication cable is pulled out from the device, or one of the devices cannot be transmitted to or received from the audio network due to a failure. Including cases. In the figure, “M” indicates a master node, and “LB” indicates a device for which loopback is set.

  Then, as shown in FIG. 21 (a), when a break occurs in the connection, when the transmission path in both directions is cut, the device on both sides of the cut portion is cut. When only the transmission path in one direction is cut, the cut is made. In the device on the receiving side of the transmission path, the signal of the TL frame from the neighboring device on the side where the disconnection occurs is interrupted, or the network clock cannot be extracted.

  In this case, the device that detects that the signal is interrupted in the middle of the TL frame or that the network clock cannot be extracted determines that a disconnection has occurred on that side, and immediately selects the selector on the detected side as a return line. Switch to the / ITL frame transmission unit side, and set the loopback of the transmission path of the TL frame to the side that detected the disconnection.

For example, when the second reception I / F 33 shown in FIG. 8 detects disconnection, the selector 37 is switched to the return line side and the selector 36 is switched to the ITL frame transmission unit 54 side.
However, this only indicates that the transmission path from the transmission I / F of the adjacent device to the second reception I / F 33 of the own device has been disconnected, and reception of the adjacent device from the second transmission I / F 32 of the own device. It is not certain whether or not the communication path leading to the I / F has been disconnected, and further whether or not the adjacent device has detected disconnection.

  Therefore, a disconnection notification command for notifying the occurrence of disconnection is transmitted from the transmission I / F (here, the second transmission I / F 32) corresponding to the reception I / F that has detected disconnection to the adjacent device. This command is generated by the ITL frame transmission unit 54 in the format of the ITL frame 120 and supplied to the transmission I / F. The disconnection notification command can reliably notify the adjacent device that the disconnection has occurred.

  Note that if the transmission path in both directions is disconnected, the adjacent device must have detected disconnection, so there is no problem even if the disconnect notification command does not arrive. Further, the disconnection notification command is periodically transmitted until the disconnection is resolved or a new apparatus is connected and a connection detection (AS) command is received from the disconnection side.

  (B) shows a state in which the devices on both sides of the cutting point set a loopback on the side where the cutting is detected. In the example shown in the figure, this forms a transmission path that circulates from apparatus A to apparatus D and a transmission path that circulates between apparatus E and apparatus F.

  When a disconnection occurs, each device may set a loopback during the passage of the TL frame. In this case, the TL frame being transmitted is damaged. However, even in this case, as described later, each node in the system can detect a TL frame breakage, and the master node can also discard the broken frame and create a new frame, which is not a big problem. Therefore, of the two device groups generated by the disconnection, the side on which the master node is present loses the data described in the TL frames 0 to 2 depending on the disconnection location and timing, but continues the operation in the RTL mode. Can do.

On the other hand, an apparatus that has been disconnected from the master node due to disconnection can no longer operate in the RTL mode because the TL frame transmitted by the master node no longer arrives. Each device can determine whether or not it has been disconnected from the master node by disconnection by referring to the topology table. Therefore, a device that has been determined to be disconnected from the master node resets itself and is set to the opposite side from the disconnection side. Also sends a reset request.
Then, all the nodes separated from the master node by the process shown in FIG. 13 once return to the ITL mode as shown in (c).

  However, after that, the processing shown in FIG. 9 is started as appropriate, and devices E and F automatically set up the TTL mode system as shown in (d) in the same procedure as described with reference to FIG. Can be formed. When the disconnected connection is restored, the devices E and F that have been disconnected can be incorporated into a system operating in the RTL mode in the same procedure as described with reference to FIG. .

  Note that the device that has detected the disconnection sequentially notifies the device on the opposite side of the disconnection location of the disconnection based on the management data in the ITL frame or TL frame. Then, each device that has received the disconnection notification deletes information about the device connected before the disconnection location from the topology table.

  In addition, when the head of the TL frame is located in the device E or the device F at the time of the occurrence of the disconnection, the TL frame may continue to circulate between the devices E and F if nothing is supported. Therefore, in order to prevent such a situation, it is preferable to confirm the frame serial number when receiving the TL frame, and when the TL frame having the same serial number is received twice, the TL frame is discarded without being folded.

FIG. 22 shows another example of the procedure for changing the system configuration at the time of disconnection.
This figure shows an example when the apparatus is stopped. Even if there is no change in the connection, it is conceivable that the apparatus is stopped due to sudden power off. Also in this case, the devices on both sides of the stopped device cannot detect the network clock from the adjacent device, and this is used as a trigger to detect the disconnection of the transmission path as shown in FIG. be able to. In the devices (D, F) next to the stopped device, the stop of the device cannot be distinguished from the disconnection of the connection, but there is no particular problem because the coping process is the same.

  That is, as shown in FIGS. 22B and 22C, as in the case of FIG. 21, the apparatus that detects the disconnection of the transmission path sets the return to the side that detected the disconnection, and the master node disconnects. A TL frame that is broken at the time of occurrence is discarded, and generation and transmission of a new TL frame are continued. As a result, the TL frame is transmitted to the transmission path on the side where the master node is present even after the disconnection occurs, and transmission of waveform data, Ethernet frames, etc. can be continued within a range in which the transmission path can be maintained. .

Even if the functions of the devices do not stop completely, the control unit 40 may hang up or the like, and data reading / writing with respect to the TL frame may not be normally performed. If the transmission of the TL frame is continued in this state, the accuracy of the content cannot be guaranteed. Therefore, when a certain device falls into this state, the device stops functioning as shown in FIG. It is preferable to change the configuration.

3. Next, data reading / writing with respect to the TL frame will be described.
The operations and processes described here relate to the RTL mode. However, in the TTL mode, exactly the same processing as in the RTL mode can be adopted except that waveform data is not read / written from / to the TL frame.

  The operations and processes described here are processes when TL frame data is input to a data input / output unit that reads and writes waveform data and Ethernet frames. When data of a TL frame is input to a data input / output unit that does not read / write waveform data or Ethernet frames, processing related to input / output of these data is not performed. In this case, since the master node does not generate a new TL frame, the same processing as that of the slave node is performed.

  For convenience of explanation, the code in the first data input / output unit 10 is used as the code of the buffer and the transmission / reception unit provided in the data input / output unit of the network I / F card 215. However, when data is read and written using the second data input / output unit 20, it goes without saying that each unit included in the second data input / output unit 20 operates.

3.1 Generation of TL Frame First, generation of the TL frame 100 in the master node will be described.
As already described, in the audio network system of this embodiment, only the master node generates a new TL frame (different in frame ID). Then, the master node generates a new TL frame by processing a part of the data of the TL frame transmitted by itself and returning around the transmission path once.
The contents of this processing are updating the header and management data (including frame ID) and writing the waveform data and control data transmitted by the master node. The waveform data and control data written by other nodes are Then, it is left as it is in a new TL frame.

  However, when such a generation method is adopted, if a new TL frame is generated without checking the error of the returned TL frame, there is a possibility that a large noise is generated in the transmitted waveform data. Therefore, in the master node of this embodiment, the entire TL frame returned around the transmission path is temporarily stored in the buffer, and after confirming that the entire TL frame has been normally received, the TL frame Based on the above, a new TL frame is generated.

  If the master node cannot receive the TL frame, a new TL frame must be generated based on another TL frame. Therefore, if the TL frame that has been normally received, that is, the latest TL frame that has normally circulated through the loop transmission path, is stored separately from the transmission and reception, and the TL frame cannot be received normally. The TL frame that was scheduled to be generated based on the TL frame is generated based on the stored TL frame.

  For this reason, in the master node, as shown in FIG. 23, in the data input / output unit that generates the TL frame, the TL frame processing buffer provided in the TL frame transmission unit 18 is composed of a plurality of buffers. The function of “transmission buffer (also serving as storage buffer)” or “reception buffer” can be assigned to each buffer. In the TL frame transmission unit 18, (k + 1) more buffers than the period update amount k are required.

Here, FIG. 24 shows a timing example of transmission / reception and generation of a TL frame in the master node. In this figure, S is an integer and is a number indicating what number each period of the word clock is. This S is also used as a frame ID indicating a TL frame transmitted by the master node in the Sth cycle.

  As described with reference to FIGS. 5 and 6, the master node transmits one TL frame for each sampling period. Further, this figure shows an example in which the period update amount k is “2”. In this case, the head of the transmitted TL frame circulates in the system at about one sampling period. In many cases, as shown in FIG. 24, before the entire reception of the Sth TL frame is completed, transmission of the (S + 1) th TL frame must be started. Further, the entire Sth TL frame is received by a predetermined time α before the transmission of the S + 2nd TL frame is started before the new TL frame is prepared in the master node. In FIG. 24, the predetermined time α is indicated by a symbol X.

In this case, the transmission of the Sth TL frame stored in the transmission buffer and the storage of the received S-1th TL frame in the reception buffer are performed in parallel. In the TL frame transmission unit 18, the reception buffer may be a buffer next to the current transmission buffer. The data that the master node should read from the TL frame may be read when stored in the reception buffer, or may be read after being stored. When the reception of the S-1st TL frame is completed, the received TL frame is checked for errors. If there is no abnormality, the reception buffer is designated as the next transmission buffer, and the designated transmission buffer is designated. Designates the buffer next to (current receive buffer) as the next receive buffer. Then, the S-1st TL frame stored in the next transmission buffer is processed to generate the S + 1th TL frame.

  Furthermore, since the Sth TL frame will be returned soon, the prepared next buffer is changed to a reception buffer, and storage of the received Sth TL frame is started. Subsequently, when transmission of the S-th TL frame is completed, the transmission buffer is released.

  Then, at the start timing of the next word clock, the prepared next buffer is changed to a transmission buffer, and transmission of the (S + 1) th TL frame stored therein is started. Thereafter, the Sth TL frame is started. When reception of the TL frame is completed, an error check of the received TL frame is performed. If there is no abnormality, the reception buffer storing the TL frame is designated as the next transmission buffer, and the designated transmission buffer (current reception Buffer next) is designated as the next receive buffer. Then, the Sth TL frame stored in the next transmission buffer is processed to generate the S + 2nd TL frame.

By repeating the above procedure, a new TL frame can always be generated based on a TL frame that can be determined to be normal as a whole.
The first and second TL frames are preferably generated based on a predetermined template because there is no TL frame as a base.

  Further, instead of processing the TL frame in the frame buffer, as in the case of the slave node, at the time of output, the TL frame is read from the buffer, and the header and contents of the read TL frame are read out by the waveform data transmission buffer 16, The data may be output while being replaced by data from the TL data transmission buffer 17 and the ITL data transmission buffer 53. In this case, the difference is that the TL frame as received is stored in the transmission buffer, but the required number of buffers is also (k + 1).

  Also, if the operation speed of each buffer is doubled so that reception is possible while transmitting, the “transmission buffer” at that time is used as a “reception buffer” at the same time when the TL frame returns to the master node. Therefore, the number of buffers can be reduced to k, which is one less than the above-described embodiment.

  FIG. 25 shows the transmission / reception and generation timing of the TL frame in the master node when the Sth and subsequent TL frames are not normally circulated through the loop-shaped transmission path. Here, the case where it is not normal means that, when an abnormality is detected in the frame at the time when the master node receives the TL frame, an abnormality is detected in another node, and that fact is recorded in the frame. This includes cases where

  In this case, when the master node generates the S + 2nd TL frame based on the Sth TL frame that is not normally circulated (data may be destroyed), the transmitted waveform data becomes discontinuous. Noise may occur. Therefore, the master node that has detected that the frame has not circulated normally discards the TL frame in the reception buffer, designates the buffer as the next reception buffer, and sets the current transmission buffer as the next transmission buffer. specify. At that time, the transmission buffer is still transmitting, and a new TL frame is generated after the transmission is completed. That is, when the transmission of the (S + 1) th TL frame is completed, the master node stores the (S + 1) th TL frame stored in the next transmission buffer (the latest TL frame that has been confirmed to have normally circulated through the transmission path). (Including data of -1st TL frame) to generate an S + 2nd TL frame.

  If the S + 1th TL frame cannot be received normally, the transmission buffer is designated as the next transmission buffer again when the S + 3rd TL frame is generated, and the transmission of the S + 2nd TL frame is completed. Then, the S + 3rd TL frame is generated based on the stored S + 2nd TL frame. Thereafter, until the TL frame can be normally received, the same buffer is repeatedly used as the transmission buffer, and a new one is generated based on the TL frame (including the data of the S-1st TL frame) stored in the transmission buffer. Continue generating TL frames.

  Even in this way, among the data described in the S-1st TL frame, the data that the master node transmits to the next node as it is without being overwritten is also the S + 3rd TL frame. It remains unchanged in the TL frame and the subsequent TL frame. Therefore, the same result as that in the case where the data of the (S-1) -th TL frame is stored separately and a new TL frame is generated each time based on the stored TL frame can be obtained.

Next, processing for realizing the operations shown in FIGS. 24 and 25 in the master node will be described.
First, FIG. 26 shows a flowchart of processing executed when the master node detects reception start of the S-th TL frame.
When the CPU of the control unit 40 in the master node detects the start of reception of the S-th TL frame, it starts the process shown in FIG. First, the ring ID and the frame ID described as management data in the received frame are confirmed (S121), and it is determined whether or not the values are correct (S122). The frame ID is a correct value if it is a serial number with the previous TL frame. The ring ID is a correct value if it is the ID of the transmission path to which the received I / F that received the frame belongs.

  Then, if the frame ID and the ring ID are correct values, there is no particular problem, so the processing of FIG. 26 is terminated, and reception of the TL frame and accumulation in the buffer are continued. However, if these values are abnormal, it is possible that a frame is missing or the shape of the transmission path is changed. Therefore, in the error processing (S123), it is stored that there is an error in the frame, and it is determined that there is an error in the next step S132 in FIG.

Next, FIG. 27 shows a flowchart of processing executed when the master node detects completion of reception of the S-th TL frame.
When the CPU of the control unit 40 in the master node detects completion of reception of the S-th TL frame, it starts the processing shown in FIG. First, the FCS 105 detects whether there is an error in the TL frame that has been received (S131). If there is no error and the value of the error flag EDF described in the received TL frame is “0” indicating no error (S132), it is determined that the received TL frame has normally circulated through the transmission path. Then, it determines to generate the S + 2nd TL frame based on the received Sth TL frame (S133). A TL frame that is a base for generating a new TL frame is referred to as a “target frame”.

Thereafter, a new frame ID is written into the target frame to form a new TL frame (S134), and waveform data, Ethernet frame, ITL frame, and other information are read and written (S135 to S138). ), The data to be output is written in the S + 2nd TL frame.
What data is read from and written to the frame is as described with reference to FIG. Further, the processes in steps S135 to S138 are not in the order, and may be performed in a process order in which only reading is performed first and then writing is performed.
For the ITL frame, even when there is no data to be written, data indicating that is written in the ITL frame area 106. This data can be described as data of a block having the number of blocks “1”, the block number “1”, and the data size “0”, for example. This also applies to the ITL frame writing process in other steps.

  Then, after step S138, FCS is added to the target frame to complete it as a TL frame (S139), wait until the timing of the S + 2nd word clock (S140), and the generated S + 2 in accordance with the timing of the word clock Transmission of the TL frame is started (S141).

  On the other hand, if there is an error or the value of the error flag EDF is “1” indicating that there is an error in step S132, it is determined that the received TL frame does not normally circulate through the transmission path, and the transmission path Is determined to generate the S + 2nd TL frame based on the latest TL frame that has been confirmed to have been normally circulated (S142). Also in this case, a TL frame that is a base for generating a new TL frame is referred to as a “target frame”.

  Thereafter, a free token is written into the target frame (S143). This free token is data indicating that the Ethernet frame area 106 of the TL frame 100 is not currently used, and a node desiring to transmit an Ethernet frame may write data to the Ethernet frame area 106. In this embodiment, the free token is written as the value of the transmission source ID (for example, “0”).

  Note that the free token is written in step S143 for the Ethernet frame region 106 because there is no point in retransmitting the same data already transmitted in the past as described in the target frame. Is to release. After that, there are cases where the master node itself writes Ethernet frame data to be transmitted to the Ethernet frame area 106.

  Further, the CPU then performs error processing associated with NO in step S132 (S144). This process is a process associated with the fact that the data described in the received TL frame is not reliable, similarly to the process in the slave node described later with reference to FIG. In addition, processing such as notifying an error to an upper layer may be performed.

After step S144, a new frame ID is written into the target frame to form a new TL frame (S145), and waveform data, Ethernet frame, ITL frame, and other information are written. (S146 to S149), the data to be output is written in the S + 2nd TL frame. The processing in steps S146 to S149 is out of order as in the case of steps S135 to S138, but here it is not necessary to read data from the target frame.
After step S149, the process proceeds to step S139, and transmission of the generated new TL frame is started in the same manner as in the case of no error, and the process ends.

By performing the above processing, the master node can generate a new TL frame based on the TL frame that has been confirmed to have normally circulated back through the transmission path, so that the correct TL frame is always obtained. Can be generated.
Even if the value of the error flag EDF is “1”, if there is no error in the received TL frame itself, the data written by the immediately preceding node can be trusted, and therefore, among the data of the received TL frame, Only data in the ITL frame area may be read out and used for processing.

  The operation described above with reference to FIGS. 24 to 27 was performed when the periodic update amount k is “2”, but when the periodic update amount k is a value larger than 2, “ The operation similar to that in the case where the periodic update amount k is “2” is performed with “the generation of the S + k-th TL frame based on the S-th TL frame” as a basic operation at normal time.

  That is, in the operation corresponding to the timing diagram of FIG. 24, when the reception of the Sth TL frame is completed normally, the master node generates the S + kth TL frame based on the TL frame, and the S + kth word clock Start transmission at the timing. In the operation corresponding to FIG. 25, when the S-th TL frame cannot be normally received, the master node waits for the completion of transmission of the S + k−1-th TL frame, and includes the “last” included in the TL frame. The S + k-th TL frame is generated based on the “normally received TL frame data”, and transmission is started at the timing of the S + k-th word clock.

  By increasing the period update amount k, the upper limit time of TL frame circulation in the audio network system can be increased, and the distance between nodes can be increased by that amount, or the number of nodes incorporated in the system can be increased. it can. However, there is a trade-off that the transmission delay of the acoustic signal in the audio network increases as the period update amount k increases.

3.3 Use of Data in Slave Node As described with reference to FIGS. 6 and 8, etc., each node operating in the RTL mode in the audio network system reads data used by the own device from the TL frame. Write data to be transmitted to other devices in the TL frame.
Next, processing related to transmission / reception of a TL frame in the slave node will be described.
First, FIG. 28 shows a flowchart of processing executed when the slave node detects reception start of the S-th TL frame.

  When the CPU of the control unit 40 in the slave node detects the reception start of the S-th TL frame, it starts the process shown in FIG. First, the ring ID and the frame ID described as management data in the TL frame being received are confirmed (S161), and it is determined whether or not the values are correct (S162). This determination is the same as in steps S121 and S122 of FIG. 26 in the master node. If it is not correct, the received TL frame is directly passed through as error processing (S171). In this case, subsequent nodes on the transmission path also pass through the TL frame and return to the master node. Further, as in the case of the FCS error, the error flag EDF may be set to “1”.

On the other hand, if there is no problem in step S162, the waveform data, Ethernet frame, ITL frame, and other information are read from and written to the received TL frame (S163 to S166).
As described in the description of FIG. 8, the slave node reads / writes data with respect to the received TL frame without waiting for the completion of reception of the TL frame, and also starts transmission to the next node. Therefore, these processes are sequentially performed at an appropriate timing according to the progress of frame reception, and do not always follow the order of description in the flowchart. Further, what data is read from and written to the frame is as described with reference to FIG. Furthermore, transmission to the next node is started and progressed independently of the processing of FIG. 28 at the timing when a predetermined amount of data of the frame is accumulated.

For this reason, at the time of reading / writing data from / to the TL frame, the slave node cannot grasp the presence / absence of an error in the frame, but this point can be dealt with by processing shown in FIGS. 29, 31 and 32 described later. To do.
If the FCS of the TL frame can be received after step S166, the presence or absence of an error in the TL frame being received is detected by the FCS (S167). If there is an error (S168), the error flag EDF of the TL frame being received is set to “1” indicating that there is an error (S169). If there is an error here, it can be seen that the accuracy of the data described in the received TL frame cannot be guaranteed. However, since the data written and output by itself in the TL frame overwrites the original data, accuracy can be guaranteed.

If there is no error in step S168 , the value of the error flag EDF is not changed and is left as it is even if “1” is set. This is because the error flag EDF is a flag indicating whether or not an error has occurred even once during the circulation of the TL frame.
In either case, finally, the correct FCS is assigned to the received TL frame (S170), and the process is terminated. By giving this FCS, the destination node recognizes that the frame output by this node has no error. If the value of the error flag EDF is “1”, it can be recognized that an error has occurred somewhere between the master node and the own node.

  By executing the above processing, the slave node can read and write necessary data for the TL frame before transmitting the received TL frame to the next node.

FIG. 29 shows a flowchart of processing executed when the slave node detects completion of reception of the S-th TL frame.
This process is a process for determining whether to accept the data read from the TL frame according to the error check result of the received TL frame. Then, when the CPU of the control unit 40 in the slave node detects the start of reception of the S-th TL frame, it starts the process shown in FIG.

  First, when there is an FCS error or the value of the error flag EDF is “1” (S181), it can be seen that the accuracy of the waveform data read from the S-th TL frame cannot be guaranteed. Therefore, the data is discarded, the waveform data of the previous cycle is held, and the data of the Sth cycle is used instead of the read waveform data (S182). Although illustration is omitted, if YES in step S181, the other information read in step S166 may be discarded.

If there is an FCS error (S183), it can be seen that the accuracy of the data read from the ITL frame area 107 of the Sth TL frame cannot be guaranteed. Therefore, the ITL frame including the data is discarded (S184). This is because when the ITL frame is divided into a plurality of blocks and described in the ITL frame area 107, the accuracy of the entire ITL frame cannot be guaranteed if even one block cannot guarantee the accuracy.
Thus, the process of FIG. 29 is completed.

By executing the above processing, even if the slave node reads / writes data to / from the TL frame before confirming the presence / absence of an error in the received TL frame, the error data is processed later from the subsequent processing. Can be eliminated.
In FIG. 29, there is no processing for eliminating data in the Ethernet frame area, but this processing will be described in the next section.

If there is no FCS error, even if the value of the error flag EDF is “1”, the accuracy of the data in the ITL frame area 107 can be guaranteed. When data to be read by the own node is written in the ITL frame area 107, the data is written in the immediately preceding node, and no transmission error has occurred between the node and the own node. This is because it is guaranteed by the FCS.

  Further, as a modification of the processing shown in FIG. 28, it is conceivable that FCS is not given in step S170. In this case, the TL frame in which an error has occurred once circulates through the transmission path with the error and returns to the master node. For this reason, it is not necessary to notify the previous node of the occurrence of the error by the error flag EDF, but the accuracy of the data once including the ITL frame area 107 cannot be guaranteed for the frame in which the error has occurred.

3.4 Transmission / Reception of Ethernet Frame Data As described above, in the audio network system 1, an Ethernet frame is described in a TL frame so that it can be transmitted / received between arbitrary nodes. However, unlike the waveform data, an Ethernet frame is a request for transmission at any time asynchronously at each node. For this reason, the Ethernet frame has a transmission / reception control function different from that for waveform data.

Next, this point will be described. Note that the processes and operations described below are common to the master node and the slave node.
First, in the acoustic signal processing device 2, it is the MAC processing unit 14 of the network I / F card 215 that generates an Ethernet frame to be transmitted and receives the received Ethernet frame. Each unit of the network I / F card 215 including the control unit 40 is positioned to mediate the transmission / reception.

  Here, in the transmission / reception of the Ethernet frame, the transmission side transmits the frame to all devices in the network, and the reception side performs processing of discarding the Ethernet frame that is not addressed to the own device. Therefore, the transmission / reception control of the present embodiment is in line with this. However, it is the processing performed by the MAC processing unit 14 that discards a frame that is not addressed to its own device, and the control unit 40 of the network I / F card 215 passes it to all the MAC processing units 14 that have been properly transmitted.

That is, the control unit 40 performs processing corresponding to the physical layer (PHY) of Ethernet, and the “upper layer” in this section refers to the MAC processing unit 14 that performs processing of the MAC layer. The CPU 201 on the main body side is a higher layer.
Accordingly, the MAC processing unit 14 itself generates an Ethernet frame for transmitting the data (IP packet or the like) transmission request from the CPU 201 or extracts necessary data from the Ethernet frame addressed to the own node. Processing that is passed to the CPU 201 is performed.

Here, a process executed by the CPU of the control unit 40 in order to transmit / receive the Ethernet frame as described above will be described.
First, FIG. 30 shows a flowchart of processing executed when the CPU of the control unit 40 receives an Ethernet frame to be transmitted from an upper layer.
When the CPU of the control unit 40 receives the Ethernet frame to be transmitted from the CPU 201 on the main body side which is the upper layer, the CPU 40 starts the processing shown in FIG. First, the data of the received Ethernet frame is written in the TL data transmission buffer 17 (S191).

After that, if there is no free space for the maximum frame size remaining in the written buffer (S192), if an Ethernet frame is received any more, it cannot be processed properly, and the upper layer is instructed to interrupt the transfer (S193). ) End the process. If there is an empty area, the process is terminated as it is.
With the above processing, the CPU of the control unit 40 can put the Ethernet frame received from the upper layer into a transmission standby state. Note that the transfer interruption instructed to the upper layer is canceled as appropriate when the capacity of the TL data transmission buffer 17 is sufficiently secured.

Next, FIG. 31 shows a flowchart of processing executed when the CPU of the control unit 40 reads data in the Ethernet frame area of the TL frame. Here, although this processing is described as being executed by the CPU of the control unit 40, a part of the hardware of the TL frame reception unit 11 and the TL frame transmission unit 18 may be shared.
When the CPU of the control unit 40 reads data in the Ethernet frame area 106 of the TL frame 100 in the process of step S136 of FIG. 27 or step S164 of FIG. 28, the CPU of the control unit 40 starts the process shown in FIG.

First, it is determined what is described as the transmission source ID in the read data (S201). First, it is only necessary to distinguish between a free token, its own node ID, and the like.
Among these, the free token is data indicating that the Ethernet frame area 106 of the TL frame 100 is not currently used and a node desiring to transmit the Ethernet frame may write data to the Ethernet frame area 106 as described above. It is. In this embodiment, the free token is written as a specific value (eg, “0”) of the transmission source ID. Others are usually IDs of other nodes, but if the TL frame in which the data is described is damaged, the data may be meaningless at all.

  If the token is a free token in step S201, the captured data is not Ethernet frame data, and the captured data is discarded (S202). In addition, since it is understood that the transmission right of the Ethernet frame has been given to the own node, the process proceeds to the processing after step S203 regarding the transmission of the Ethernet frame.

  In this process, if there is data to be transmitted to the TL data transmission buffer 17 (S203), the data to be transmitted is written to the Ethernet frame area 106 of the TL frame 100 passing through the own node. In addition, as described with reference to FIGS. 2 and 3, the transmission of the Ethernet frame is performed by dividing the frame into blocks, and data for one block is written in one TL frame.

  More specifically, if an Ethernet frame is being transmitted (a state in which only some blocks are transmitted) (S204), data for the next block of the frame being transmitted is prepared (S205), and the data of that block is prepared. Is written in the Ethernet frame area 106 (S206). The block preparation is a format in which one block is cut out from the data of the Ethernet frame, and data such as the number of blocks and the block number is attached and written to the Ethernet frame area 106 as shown in FIG. Refers to the creation of data.

If transmission is not in progress at step S204 (if transmission of a new Ethernet frame is about to start), specify the frame to be transmitted and the number of blocks required for transmission (S207), and prepare the first block of the frame to be transmitted Then, the data of the block is written into the Ethernet frame area 106 (S206).
In either case, the process is terminated after step S206.

  If it is the self node ID in step S201, the captured data is considered to be the data that the self node has written and transmitted last time, which has returned around the transmission path. Therefore, referring to the block number and contents of the data and confirming this (S209), since the captured data is not the data of the Ethernet frame transmitted from another node, the captured data is discarded (S210). ). Further, here, since the node that has written to the Ethernet frame area 106 last time can maintain the transmission right until the transmission of the data for one Ethernet frame is completed, this case also relates to the transmission of the Ethernet frame. It progresses to the process after step S211.

In this process, if there is a block that has not been transmitted yet in the Ethernet frame that is being transmitted (S211), data for the next block of the frame that is being transmitted is prepared (S212), and the data of that block is stored in its own node. Is written in the Ethernet frame area 106 of the TL frame 100 passing through (S213), and the processing is terminated.
If transmission of all blocks is completed, a free token is written in the Ethernet frame area 106 (S214), the transmission right is transferred to another device, and the transmission completion of the frame is notified to the upper layer ( S215), the process is terminated.

If NO in step S209, an error may have occurred in the transmission of the Ethernet frame. Therefore, error processing (S216) is performed. As this process, for example, it is conceivable to stop the transmission of the currently transmitted Ethernet frame and notify the upper layer and all nodes in the system of the occurrence of the error. This notification can be performed by writing invalid data of a predetermined format in the Ethernet frame area 106 of the TL frame 100 and transmitting it.
Note that retransmission of an Ethernet frame when an error occurs is not automatically performed on the network I / F card 215 side, and a request is made from the upper layer to the network I / F card 215 if necessary.

If it is other in step S201, the process proceeds to step S217 in FIG. In this case, since the captured data is considered to be data of an Ethernet frame transmitted from another node, processing related to reception of the Ethernet frame is performed.
First, it is confirmed whether there is a missing block in the captured data (S217). This process confirms that the blocks are received in numerical order for each transmission source. Even if data from a plurality of transmission sources are alternately received, it is sufficient that they are in numerical order when viewed from each transmission source.

  If there is no missing block (S218), the frame data of the fetched block is written into the TL data reception buffer 13 (S219). At this time, it is only necessary to write only the portion of the read frame data of the Ethernet frame area 106 that becomes the Ethernet frame when concatenated. The data such as the number of blocks and the block number can be stored for confirmation of missing. For example, it is not necessary to write to the TL data reception buffer 13. Even if there is an empty area at the end, it is not necessary to store the data in that part. When data from a plurality of transmission sources coexist, the data is stored separately for each transmission source.

  If the data of all the blocks for one Ethernet frame is prepared in the TL data reception buffer 13 by writing in step S219 (S220), the data of the Ethernet frame obtained by concatenating the accumulated data of each block is stored. The data is output to the upper layer (S221), and the process is terminated (see FIG. 31). If not, the process ends.

  If there is a loss in step S218, it is considered that there is a problem in data transmission, and the data accumulated in the TL data reception buffer is cleared (S222). At this time, if the data transmission source can be specified, only the data from the transmission source may be cleared. Further, the fetched data is invalid data written in step S216 in FIG. 31, the node ID of the fetched data is not that of a node in the system, or the data is completely unknown. In this case, NO is determined in step S218, and the data is cleared.

  Further, after step S222, the slave node ends the process as it is, but the master node performs error processing (S223) and confirms the communication status. In this process, for example, test data is written in the Ethernet frame area 106 and transmitted, and it is confirmed that the test data returns to normal. When it returns to normal, it is recognized that the error is temporary, a free token is written in the Ethernet frame area 106, and the Ethernet frame area 106 can be used again.

  In the audio network system 1, each device executes the above processing to appropriately arbitrate the transmission right of the Ethernet frame between the devices, and the Ethernet frame between the nodes using the Ethernet frame area 106 of the TL frame 100. Can send and receive.

  It is also conceivable that a node that has written data in the Ethernet frame area 106 is excluded from the system due to the disconnection or the like described with reference to FIGS. In this case, since there is no node in the system that determines that the transmission source ID is its own node ID in step S201 in FIG. 31, no node will rewrite the Ethernet frame area 106.

In order to deal with such a situation, for example, the master node checks the source ID against the contents of the topology table, and discards the data in the Ethernet frame area 106 when the source ID is not the MAC address of the node in the system. A free token may be written. In this way, when the node that has written data in the Ethernet frame area 106 is excluded from the system, the Ethernet frame area 106 can be quickly released.
Although the Ethernet frame area 106 can be released also by the error processing in step S223, in this case, the confirmation of the topology table is performed in order to confirm transmission / reception of test data after confirming that the same data has been read twice. It takes time to open compared to.

  Further, in the example of FIG. 31, once each node starts transmitting data, it can maintain the transmission right until transmission of data for one frame is completed. However, other mediation algorithms may be employed. For example, every time one block is transmitted, a free token is written and the transmission right is transferred to the next node, or conversely, the transmission right can be maintained until all necessary data is transmitted even in a plurality of frames. Of course, various other algorithms are conceivable.

Further, the Ethernet frame area may be divided into a plurality, and a free token may be prepared for each area so that the transmission right can be arbitrated. In this case, the notification of the completion of transmission in step S215 in FIG. 31 is performed when data transmission completion has been confirmed for all areas.
Further, regarding the data received and written to the TL data reception buffer 13, if data of all blocks is not prepared within a predetermined time, it may be regarded as a communication error and the data received so far may be cleared. .

4). Modification The description of the embodiment is finished as described above, but it goes without saying that the configuration of the apparatus, the configuration of data, the specific processing content, and the like are not limited to those described in the above embodiment.
For example, it is not essential to circulate one TL frame in one sampling period. A plurality of TL frames are circulated in one sampling period, or one TL frame is circulated in a plurality of sampling periods. It is also possible to describe the waveform data.

  In the case where a plurality of TL frames are circulated in one sampling period, the writing / reading control to the Ethernet frame area using the free token may be performed independently for each TL frame in the sampling period. In this case, for example, different nodes can write to the Ethernet frame area for the first TL frame and the second TL frame of a certain sampling period.

  In the above-described embodiment, the description has been made so that the functions of the master node and the slave node are different. However, which device becomes the master node depends on the device itself until the audio network system is actually formed. Is not recognized. Therefore, each device is configured so that it can function as both a master node and a slave. When the TTL mode shifts, it is determined that the device itself becomes a temporary master, or an OM command receives a designation to become an RTL mode master. It is advisable to enable an appropriate function depending on whether or not. However, a device that does not have a master node function may be incorporated into the system, and the device may not automatically become a master (including provisional) and cannot be designated as a master. At this time, if the master cannot be determined for this reason, it is only necessary to prevent the transition from the ITL mode to the TTL mode.

Of course, the ratio of the area of the waveform data to the control data may be changed for the TL frame configuration. The size of any area may be set to zero.
In addition, in the above-described embodiment, the period update amount k is a variable value, but may be a fixed value. In this case, the upper limit time corresponding to the periodic update amount k is also a fixed value, and the number of nodes that can be added to the system is limited by the upper limit time.
The various frames including the TL frame are not limited to the IEEE 802.3 format, but may be any other format.

In the above-described embodiment, the sampling frequency is 96 kHz, but it can be designed with an arbitrary frequency such as 88.2 kHz, 192 kHz. Further, the sampling frequency may be switched.
These modifications and the modifications described in the description of the embodiments can be applied in any combination within a consistent range. Conversely, the network system and the acoustic signal processing device need not have all the features described in the description of the embodiment.

As is clear from the above description, according to the network system and the communication device of the present invention, a loop-like transmission frame formed between the devices, which is generated by the master node and has a plurality of acoustic signal storage areas, is formed. When configuring a network system that circulates along a certain transmission path at a fixed period, even if there is a device group that has been disconnected from the master node for some reason, a loop-shaped transmission path between the device groups Thus, it is possible to perform data transmission using a frame that circulates at a constant cycle along the line.
Therefore, the convenience of the network system can be improved by applying the present invention.

1 is a diagram showing an outline of an audio network system which is an embodiment of a network system of the present invention. It is a figure which shows the structural example of the TL frame transmitted with the transmission path shown in FIG. FIG. 3 is a diagram showing a more detailed configuration of a waveform data area, an Ethernet frame area, and an ITL frame area in the TL frame shown in FIG. 2. It is a figure which shows the data structure of an ITL frame. It is a figure which shows the transmission timing of TL frame shown in FIG.

It is a figure which shows the transmission condition of the TL frame shown in FIG. 2 at the time of transmission of the acoustic signal of the single mode on an audio network system. It is a figure which shows the hardware constitutions of the acoustic signal processing apparatus used as each node which comprises the audio network system shown in FIG. It is a figure which shows the structure of the network I / F card shown in FIG. 7 in detail. It is a flowchart of the process regarding the construction | assembly of a system which CPU of the control part of a network I / F card performs at the time of power ON and reset. 10 is a flowchart of physical connection confirmation processing shown in FIG. 9.

It is a figure which shows the example of a topology table. 10 is a flowchart of logical connection preparation processing shown in FIG. 9. It is a flowchart of a process at the time of receiving a reset process. 10 is a flowchart of logical connection establishment processing shown in FIG. 9. It is a flowchart of a process when an operation mode switching (OM) command is received.

It is a figure which shows the specific example of the formation procedure of an audio network system. It is a figure which shows the continuation of FIG. It is a figure which shows another example of the formation procedure of an audio network system. It is a figure which shows another example. It is a figure which shows another example.

It is a figure which shows the example of the system configuration change procedure at the time of a connection disconnection. It is a figure which shows the other example. It is a figure which shows the structure of the buffer which memorize | stores TL frame in a master node. It is a figure which shows the example of transmission / reception of a TL frame in a master node, and the generation timing. It is a figure which shows the other example.

It is a flowchart of the process performed when a master node detects the reception start of a Sth TL frame. It is a flowchart of the process performed when a master node detects the completion of reception of the Sth TL frame. It is a flowchart of the process performed when a slave node detects the reception start of a Sth TL frame. It is a flowchart of the process performed when a slave node detects the completion of reception of the Sth TL frame. It is a flowchart of the process performed when CPU of the control part of a network I / F card receives the Ethernet frame which should be transmitted from an upper layer. Similarly, it is a flowchart of processing executed when data in an Ethernet frame area of a TL frame is read. It is the flowchart of the continuation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Audio network system, 2 ... Acoustic signal processing apparatus, 10 ... 1st data input / output part, 11, 21 ... TL frame receiving part, 14, 24 ... MAC processing part, 15, 25 ... Delay buffer, 18, 28 ... TL frame transmission unit, 31, 33 ... first and second reception I / F, 32, 34 ... second and first transmission I / F, 35-38 ... selector, 40 ... control unit, 41 ... word Clock generation unit, 51, 61 ... ITL frame reception unit, 54, 64 ... ITL frame transmission unit, 70 ... Upper layer I / F, 100 ... TL frame, 110, 120 ... ITL frame, 215 ... Network I / F card, 220 ... Frame processing unit, NC1 to NC4 ... Network clock, LB1, LB2 ... Return line

Claims (12)

A plurality of nodes each having two sets of receiving means and transmitting means for performing unidirectional communication are respectively connected to one set of receiving means and transmitting means of a certain node with one set of transmitting means and receiving means of the next node. A network system formed by sequentially connecting,
Each of the nodes
Formed between the one of the plurality of nodes but are determined in the temporary master node, the temporary master node generates, transmits frames each node having a storage area of the initial communication frame for command transmission The initial communication frame is circulated at a constant cycle along the looped transmission path, and the initial communication frame is written to and / or read from the transmission frame at each node. Temporary communication mode for transmission, and
One of said plurality of nodes but has been defined as the master node, the master node generates, looped transmission path audio transport frame having a storage area of a plurality of acoustic signals is formed between the nodes Circulates at a fixed period along the line, and by writing and / or reading out the sound signal to and from the sound transmission frame at each node, communication in the sound transmission mode for transmitting the sound signal between a series of connected nodes is performed. Having communication control means for selectively executing;
If the master node is set in the network system, under the control of the master node, wherein each node starts the operation of the audio transmission mode,
When the connection between the nodes is cut off at any part of the network system, each of the nodes in the node group on the side where the master node is present is selected from the two node groups generated by the disconnection. The operation of the transmission mode is maintained and the voice transmission frame is continuously circulated along a loop-shaped transmission path formed by the nodes, and each node of the node group on the side where the master node does not exist is automatically The network system is characterized in that the operation is shifted to the temporary communication mode. The network system according to claim 1, wherein
The communication control unit of each node is a unit capable of operating in an initial communication mode in which the initial communication frame is transmitted from the transmission unit to an adjacent node connected to the transmission unit, and the activation of the node Means for operating in the initial communication mode at the time of resetting or resetting,
In the network system,
When a node located at an end of a loop transmission path formed in the voice transmission mode or the temporary communication mode detects that a node operating in the initial communication mode is directly connected to its own node The node operating in the initial communication mode is accessed, and the node is incorporated into the loop transmission path to which the own node belongs, and it is detected that the node operating in the temporary communication mode is directly connected to the own node. In this case, a reset command is sent to the node operating in the temporary communication mode to reset it, the node operation is returned to the initial communication mode, the node is accessed, and the node A network system characterized by performing an operation of being incorporated into a loop-shaped transmission path to which the device belongs. The network system according to claim 2,
When each of the nodes receives the reset command, the node resets the function of the own device relating to the formation of the loop-shaped transmission path, leaves the loop-shaped transmission path, and receives the reset command. A network system comprising a reset transmission means for transmitting a reset command to an adjacent node on the opposite side. The network system according to claim 2 or 3,
In the network system,
When a node operating in the initial communication mode detects that a node operating in the initial communication mode is directly connected to the own node, the node is negotiated with the detected node and detected. One of the registered nodes is set as the temporary master node, the local node and the detected node are shifted to the temporary communication mode, and the loop-shaped transmission path is formed between the local node and the detected node. A network system characterized by The network system according to any one of claims 2 to 4, wherein
A node located at an end of a loop-shaped transmission path formed in the voice transmission mode or the temporary communication mode forms a loop-shaped transmission path different from its own node and is operating in the voice transmission mode A network system characterized in that when it is detected that the node is directly connected to the own node, the operation of incorporating the detected node into the loop transmission path to which the own node belongs is not performed. A plurality of nodes each having two sets of receiving means and transmitting means for performing unidirectional communication are respectively connected to one set of receiving means and transmitting means of a certain node with one set of transmitting means and receiving means of the next node. A network system formed by sequentially connecting,
The network system
An initial communication mode in which each of the plurality of nodes communicates bidirectionally with an adjacent node connected to the receiving unit and the transmitting unit;
One of the plurality of nodes is defined as a temporary master node, and a transmission frame having an initial communication frame storage area for command transmission generated by the temporary master node is formed between the nodes. The initial communication frame is transmitted between a series of connected nodes by circulating at regular intervals along the looped transmission path and writing and / or reading the initial communication frame to and from the transmission frame at each node. A temporary communication mode, and
One of the plurality of nodes is defined as a master node, and an audio transmission frame having a plurality of acoustic signal storage areas generated by the master node is formed in a loop-shaped transmission path between the nodes. A sound transmission mode in which sound signals are transmitted between a series of connected nodes by performing sound signal writing and / or reading to / from the sound transmission frame at each node.
Selectively execute communication in any one of the modes,
Detect that a new node is connected to a node located at the end of the network system,
In response to the detection, it is identified whether another network system formed of one or more nodes including the new node is operating in the initial communication mode, the temporary communication mode, or the voice transmission mode. And
When the mode of the other network system is a mode having a lower priority than the mode of the network system, the other network system is incorporated in the network system, and the mode of the other network system is higher than the mode of the network system. If the mode is a high priority mode, control is performed so that the network system is incorporated into the other network system.
A network system characterized by this. The network system according to claim 6, wherein
Among the initial communication mode, the extraordinary communication mode, and the voice mode, the initial communication mode is the mode with the lowest priority and the voice transmission mode is the mode with the highest priority,
The built-in network system performs communication in a mode executed by a built-in network system. The network system according to claim 7,
The initial communication mode is a mode executed when the number of nodes constituting the network system is 1.
When both the network system and the other network system are operating in the initial communication mode, one of the nodes forming both network systems is determined as a temporary master node, and communication in the temporary communication mode is performed. A network system characterized by starting. A network system according to any one of claims 6 to 8,
At least one of said nodes is
A network system comprising master node determination means for determining one node functioning as the master node in the voice transmission mode from a node constituting the network in accordance with a user operation. A communication device functioning as the node in a network system formed by connecting a plurality of nodes,
The audio signal is written to and / or read from an audio transmission frame having a plurality of acoustic signal storage areas, which is received from one adjacent node along the transmission path of the network system, and the audio transmission frame is read from the network. A communication means for performing communication between the adjacent nodes in a voice transmission mode for sending to other nodes adjacent along the transmission path of the system;
On the network system, it is detected that there is no master node for controlling the voice transmission frame, and in response to the detection, transmission having a storage area for command transmission instead of the voice transmission frame. Communication control means for automatically shifting the operation of the communication means to a temporary communication mode in which data is transmitted / received and data indicating a command or response to the transmission frame is written and / or read. Communication device. The communication device according to claim 10,
The communication control means includes
When the communication device determines whether or not to operate as a temporary master node in the temporary communication mode, and determines that the communication device should operate as a temporary master node, periodically generate the transmission frame, A communication apparatus, wherein the generated transmission frame is sent to the other adjacent node. The communication device according to claim 10 or 11,
The communication control means includes
A communication apparatus that shifts the operation of the communication means from the temporary communication mode to the voice transmission mode in response to a master node that controls the voice transmission frame being set in the network system.

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