JPH0440133A - Ring-type lan - Google Patents

Abstract

PURPOSE:To transmit a musical sound control data and an audio data by using one LAN by encoding the musical sound control data and the audio data to symbols by the same encoding method, generating a frame by using the respective symbols, and transmitting the frame. CONSTITUTION:Based on the output timing of a transmission control signal TCTL to be outputted from a transmission data input part 9 of a packet exchange type LAN connection part 4, a music control data DT such as a key-on signal or the like is outputted from a music control data processing part 21 and inputted to the transmission data input part 9 of the packet exchange type LAN connection part 4. Next, in the packet exchange type LAN connection part 4, a frame/token bit train F/TBA is generated based on the music control data DT and this frame/token bit train F/TBA is outputted synchronously with an output clock CKT provided in the packet exchange type LAN connection part 4, and inputted to an encoding part 13 of a line exchange type LAN connection part 15.

Description

Detailed Description of the Invention "Field of Industrial Application" This invention relates to a ring type LA in which a plurality of communication stations are connected in a ring shape through a transmission path and data communication is performed between these stations.
In particular, the present invention relates to a ring-type LAN having a protocol capable of processing both a circuit-switched protocol for processing audio data and a packet-switched protocol for processing musical tone control data.

[Conventional technology] Traditionally, when playing songs and producing music sources in a music production studio, audio data that is digitally converted from voices and sounds generated from acoustic instruments, and audio data generated from electronic instruments such as synthesizers are used. The performance control data expressed by the key-on signal and the cow-off signal are handled separately.

This is based on the reasons shown below.

First, performance control data, such as a key-on signal or a key-off signal, can be sent as a signal of a predetermined length at the time each signal is generated, so it has traditionally been used to transmit data in a fun performance. Packet-switched LA
N can be used as is. Therefore, only one communication cable is required.

On the other hand, for chronologically continuous data such as audio data, data of a predetermined length, for example, 24-bit data, must be continuously sent at predetermined sampling timings.

This is not a problem when the transmission speed is sufficiently high and the amount of data is small, but it becomes a problem when multiple lines are used. Therefore, a dedicated line is required for each audio data, and in the past, communication cables for audio data were required for the number of sources or more.

Recently, music production software that can directly handle not only performance control data but also audio data has begun to appear.

Furthermore, in recent years, multimedia has come into the spotlight. This multimedia is a technology that associates and synchronizes commands that can be processed by conventional combinations such as numbers, characters, and graphics with continuous stream data in time series such as audio data and video data. It is. By using this multimedia in a combi 2-to-yo, video and audio are added to the combi-1-to, and it is possible to provide individuals with ``realism'' and ease of use that cannot be achieved with books or television. In the case of this multimedia as well, it is necessary to be able to simultaneously communicate commands and stream data.

In light of the various situations described above, it is desirable to be able to communicate both a variety of stream data, typified by audio data, and commands, typified by performance control data, in real time and without delay over a single LAN.

By the way, the command transmission speed in a packet-switched LAN has conventionally been about 4 to 10 Mbps;
The transmission speed of stream data, especially video data, is approximately 1
00MbpS is required. Furthermore, although the transmission speed of audio data is relatively low, the tolerance for transmission delay is extremely small. In this way, stream data has various properties different from those of commands.

Therefore, in order to communicate commands and stream data with different properties through one LAN, the following method can be considered.

(1) This is a method in which multiple protocols are superimposed using frequency division multiplexing. That is, one transmission line having a certain frequency bandwidth is divided into a plurality of frequency bands, channels are assigned to each frequency band, and commands or stream data are transmitted using a different protocol for each channel. For example, 1 = 100 Hz
A command is transmitted using a certain protocol in a channel in a frequency band of io1 to 200 Hz, and stream data is transmitted in a different protocol in a channel in a frequency band of io1 to 200 Hz.

(2) A method of communicating stream data and commands by time division multiplexing. That is, it is a method in which circuit switching and packet switching are performed simultaneously on one transmission path according to the type of data.

(3) This method uses ATV (asynchronous transmission mode) to handle stream data and commands using the same protocol. In this method, audio data, video data,
All commands and the like are broken down into fixed-length blocks called cells and transmitted over a transmission path.

[Problems to be Solved by the Invention] The conventional LAN described above has the following drawbacks.

In the method (1), it is necessary to prepare a modem for each frequency, which has the disadvantage that the circuit specifications become large.

Furthermore, the method (2) has the drawbacks of increased circuit scale and poor communication efficiency.

Furthermore, in the method (3), since the switching equipment uses hardware to allocate cells at high speed, there is a drawback that the circuit scale becomes large.

This invention has been made in view of the above-mentioned circumstances, and utilizes two existing technologies, circuit-switched LAN and packet-switched LAN, to allow stream data to be transmitted with a simple configuration and protocol without reducing communication efficiency. A ring-type LAN that allows commands to be communicated over a single LAN.
is intended to provide.

"Means for Solving the Problems" The present invention provides a ring-type LA in which a plurality of communication stations are connected in a ring shape through a transmission path and data communication is performed between these stations.
In N, the plurality of communication stations encode musical tone control data such as a key-on signal or a key-off signal and audio data into symbols using the same encoding method, generate frames using the symbols, and convert the frames to the It is characterized by transmission using a transmission path.

"Operation" According to the present invention, each communication station first encodes musical tone control data and audio data into symbols using the same encoding method.

Next, the communication station generates a frame using each symbol and transmits this frame to another communication station using a transmission path.

With this, musical tone control data and audio data are combined into one
The data can be transmitted using two LANs.

"Embodiment" Before describing an embodiment of the present invention, the basic idea for solving the above-mentioned problem will be explained.

The present applicants have previously jointly and independently proposed a token ring based packet-switched LAN for real-time applications.

Here, the configuration of the packet-switched LA/N connection unit used in the above-mentioned packet-switched LAN and controls the transmission and reception of signals will be described.

FIG. 5 is a block diagram showing the configuration of a packet-switched LAN connection section and its peripheral devices. 1 is a connector connected to a transmission line such as an optical fiber cable, and 2 is a receiver which receives signals transmitted via the transmission line and connector 1 and outputs a 1-bit width signal S□.

Further, 3 is a decoding unit, which decodes the frame/token bit string F/TBA from the signal S□, and also decodes the internal PL
The L circuit section extracts the bit clock CK1 from the signal S□ and outputs it.

Furthermore, 4 is a packet-switched LAN connection section. In the packet-switched LAN connection unit 4, 5 is a received bit analysis unit that constantly inspects the frame/token bit string F/TBA and detects timing signals STH regarding the start/end of the frame/token bit string F/TBA. , detects and generates ring priority P, and reservation priority R, and extracts a frame bit string FBA constituting the frame. Here, the ring priority P1 is the current priority of the token or frame transmitted on the transmission path, and the reservation priority R,. This is the priority used to perform the task.

Reference numeral 6 denotes a reception control unit which inputs the frame bit string FBA, judges whether the frame bit string FBA is addressed to the local station, and outputs received data D1 addressed to the local station. 7 inputs received data DII, and receives received data D3 based on a reception control signal RCTL output from a data processing section (not shown).
This is a received data output unit that outputs.

8 is a bit delay unit that rewrites bits while relaying the frame/token hit string F/TBA; 9
is a transmission data input unit, which inputs the transmission control signal TCTL to a data processing unit (not shown) to input the transmission data DT to be transmitted output from the data processing unit, and outputs the transmission data DT from the transmission control unit IO (described later). data request signal D
Transmission data D7 is output based on R.

Reference numeral 10 denotes a transmission control unit, which generates a token bit sequence TBA and requests data from the transmission data input unit 9 based on the transmission instruction signal TS and transmission end signal TE output from the transmission data input unit 9. By outputting the signal DR, the transmission data DT is input, a frame bit string FBA is generated, and the generated frame bit string FBA is output according to the token ring protocol.

This frame bit string FBA is generated by transmitting data DT
The data priority P extracted from the data priority P, and the ring priority Pr1 reservation priority R output from the received bit analysis unit 5,
and timing signal S? This is done based on N.

Reference numeral 11 denotes a transmission reservation section, which manually inputs the larger of the reservation priority R1 and the data priority P output from the transmission control section 10, and outputs a value corresponding to the priority while passing through the bit delay section 8. The reservation index bit Rtl of the frame/token bit string F/TBA is set. 12 is a frame/token bit string F/T output from the bit delay unit 8
This is a transmission selection unit that selects and outputs either BA or the frame/token bit string F/TBA output from the transmission control unit IO. Note that this selection is made by the transmission control unit 10.
Selection signal S output from. Based on L.

13 is a frame/token bit string F/ which is output from the transmission selection section 12 of the packet-switched LAN connection section 4.
The encoding unit 14 that encodes the TBA is a transmitter that receives the output signal SPT of the encoding unit 13 and transmits the signal SPT to another communication station via a transmission path.

For details of the above-mentioned packet-switched LAN, please refer to the specifications and drawings attached to the respective applications of Japanese Patent Application No. 1-342291 to Japanese Patent Application No. 1-342295 and Japanese Patent Application No. 1-343211. .

By the way, the packet switching type LAN connection section 4 mentioned above is
Since it can be configured using an SI (large scale integrated circuit), commands can be easily communicated by using this LSI in a packet-switched LAN.

Therefore, in the present invention, the communication of commands is performed using the above-described packet,
is a LAN using a hybrid protocol of a circuit-switched protocol for stream data and a packet-switched protocol for commands.

Next, the topology of the LAN is the packet-switched L
Due to the use of the AN connection section 4, it is of a ring type. Furthermore, the transmission method is a baseband transmission method.

There are two ways of thinking about hybridization as shown below.

The first idea is to put packet-switched LAN data on a circuit-switched LAN channel. first,
This circuit-switched LAN protocol provides N channels that allow one-to-many (or one-to-one) communication.

Therefore, N independent stream data can be handled. Furthermore, it is assumed that the stream data is transmitted using a frame having N slots corresponding to N channels, as shown in FIG.

Then, each transmitting station divides and inserts stream data into preset slots among the N slots of each frame, and time-division multiplexes this frame with sufficient timing to transmit the stream data. Send fi periodically.

On the other hand, each receiving station assembles stream data for that channel by connecting the symbols in the same numbered slots of each frame.

This allows data transmission by creating one channel for one stream of data. For example, in FIG. 6, slot 1 of frame 1
The stream data of channel 1 is assembled by connecting the data of slot 1 of frame 2 and the data of slot 1 of frame 2, and the stream data of channel 1 is assembled by connecting the data of slot 2 of frame l and the data of slot 2 of frame 2. stream data is assembled.

Furthermore, data in a packet-switched LAN is transmitted by being divided into slots in which each frame is placed.

Thereby, commands and stream data can be transmitted through one transmission path.

Here, FIG. 7 shows an example of the configuration of a control section for signal transmission and reception based on the first concept. In this figure, 1 is a connector, 4 is the above-mentioned packet-switched LAN connection section, and 15 is a circuit-switched LAN connection section that is used for a circuit-switched LAN and controls the transmission and reception of signals.

The second idea is to combine circuit-switched LAN data and packet-switched LAN data into one data. Here, an example of each data encoding method is shown below.

000: 0-level data of circuit-switched LAN 001: Level data of circuit-switched LAN O1O: 0-level data of packet-switched LAN 011: Packet-switched LAN
N rubel data Therefore, by encoding circuit-switched LAN data and packet-switched LAN data using the same encoding method, the respective data can be superimposed and transmitted as one data. At the same time, it is possible to separate each piece of data from the superimposed data.

Here, FIG. 8 shows an example of the configuration of a data transmission/reception control section based on the second concept. In this figure, parts corresponding to those in FIG. 7 are given the same reference numerals, and their explanations will be omitted. In FIG. 8, 16 is a shunt/combiner, which separates the signal transmitted via connector l into a signal for a packet-switched LAN and a signal for a line-switched LAN, and The signals output from the type LAN connection section 4 and the circuit-switched LAN connection section 15 are combined and transmitted as one signal via the connector 1. Note that the circuit-switched LAN connection section 15 in FIG.
The configuration may be different from the line-switched LAN connection section 15 shown in the figure.

By adopting the concept described above, stream data and commands such as musical tone control data can be communicated over one LAN with a simple configuration and protocol without reducing communication efficiency.

(1) Explanation of the first idea The stream data encoding method is such that when each bit of the stream data is '0', there is no level change, and when each bit is '1', the level is inverted.
(Non Return to Zero 1 nve
rted) and 4B, which represents 4 bits of data in 5 bits.
75B encoding method. FIG. 9 shows an example of the encoding method described above. In this figure, + indicates that the polarity is reversed, and - indicates that the polarity is not reversed.

In FIG. 9, (0) to (F) are symbols for data, and (BST) to (FE) are synchronization symbols for frames, which are used to find the frame. still,
The structure of the frame will be described later with reference to FIG. 1O. Further, (NC) to (Ov) are synchronization symbols for data for each slot.

In FIG. 9, (reservation) means that the use is not currently considered, but it is reserved for future use.

Next, the structure of a frame sent between each communication station will be explained using FIG. 10. This frame is of fixed length, starting with a frame start synchronization symbol (FS), followed by N slots (corresponding to N channels), and ending with a frame end synchronization symbol (FE). A preamble (PRA) is inserted between frames.

Furthermore, the size of one slot is one symbol, and this slot contains data symbols from (0) to (F) mentioned above, and a symbol indicating that there is no data in the slot (hereinafter referred to as a no data symbol). ) (NC),
A sample synchronization start symbol (C8), a data error symbol (ER) and a non-data symbol of the transmit buffer overflow symbol (OV) are entered. still,
At each receiving station, if the symbols in the same numbered slots of each frame are connected, for example, 24
However, since it is necessary to synchronize this data, the above-mentioned non-data symbol (N
C) to (OV) are used for data synchronization.

As mentioned above, by encoding the symbols used for data synchronization together with the data, data synchronization symbols (NC) to (OV) can be used at the same level in frames and channels, improving communication efficiency. This also simplifies the circuit configuration since there is no need to further decode data and synchronization data from these symbols.

Next, the representation of audio data, which is stream data obtained by connecting symbols in slots with the same number of frames, will be described. FIG. 11 shows an example of the format of audio data. The sample synchronization start symbol (CS) described above indicates the separation of each sample, and the data symbols 6a (DO to D5
) by 24-bit PCM (Pulse C
ode Modulation) value. /-The data symbol (NC) can be placed anywhere in the symbol string (the speed of the slot that is periodically transmitted by this symbol (NC) and the speed of the audio data that occurs irregularly) Make adjustments.

Also, musical tone control data is considered as packet-switched LAN data, which is another data obtained by connecting symbols in slots of the same number in a frame. Like the audio data, this data is also decoded from symbols in specific slots (described later) of the frame based on the encoding method described above. As in the case of audio data, one data symbol represents a 4-bit signal. The no data symbol (NC) may be placed anywhere in the symbol string, and is used to adjust the speed of the slot and the speed of the tone control data.

In addition, the packet-switched LAN data is used for musical tone control,
It is also used for ring failure recovery. When the packet-switched LAN bus enters a forced transmission state due to a ring abnormality, the communication station stops repeating frames and enters a forced transmission state of frames carrying only the channel corresponding to this data. The data of the packet-switched LAN is also used for maintenance such as channel assignment in the circuit-switched LAN. In addition, packet-switched LA
For details on the format and usage of the N data, please refer to the specification and drawings attached to the above-mentioned Japanese Patent Application No. 1-342291.

By the way, data in a packet-switched LAN, similar to audio data, is originally something that is repeated by each communication station on the LAN, so all communication stations use the same slot (channel) assigned to them to transmit and receive data. It is necessary to do this and repeat the data. Although this repeat processing causes a delay of at least one frame at each communication station, multiple slots are
By assigning it to AN data, the delay can be kept to a minimum.

An example to which the first concept is applied will be described below with reference to the drawings. System diagram 1 is a block diagram showing the configuration of a ring-type LAN according to an embodiment to which the first concept is applied. In FIG. 1, 171 to 174 are communication stations that perform data communication with each other, and communication stations 17. is a mask station and communication station 1 that periodically transmits and collects frames.
7. ~17 are slave stations that perform reception processing and transmission processing while repeating frames. 18 is communication station 1
7. -17. This is a transmission line such as an optical fiber cable that connects the two in a ring shape.

Here, FIG. 2 shows a block diagram of the configuration of the communication station 17 of FIG. 1. In this figure, l is a connector, and 19 is a frame F having the format shown in FIG.
, 15 is the above-mentioned circuit switching type LAN connection part, 4 is the above-mentioned packet switching type LAN connection part, 21 is a musical tone control data processing part, /< Kerato switching type LAN connection part Processing of the musical tone control data D outputted by the communication station 4 and the musical tone control data D to be transmitted to the other communication station 17
? processing.

In addition, 22 is an audio data processing unit, and the audio data DAI outputted by the line-switched LAN connection unit 15 is
It processes audio data DA7 to be transmitted to another communication station 17. Reference numeral 23 denotes an encoding unit that encodes the frame F outputted from the circuit-switched LAN connection unit 15 into a transmission signal and transmits it via the connector l and the transmission line 18.

Furthermore, in the circuit-switched LAN connection unit 15, 24 is a reception control unit that extracts symbols from the audio data slot assigned to the local station and the packet-switched LAN slot of each input frame F. ,
Instead, a no data symbol (NC) is inserted, a symbol string is generated for each slot, and a symbol string 5P11 for packet-switched LAN and audio data D are generated.
It is divided into Aw (see FIG. 11) and output. Of these, the audio data D All is output after waiting for a sample start synchronization symbol (CS), as shown in FIG.

3 is a decoding unit, which converts the input symbol string 5PII into a packet-switched LAN frame/token bit string F/
It is decoded into TBA and output in synchronization with clock CK.

13 is an encoding unit, and a packet-switched LAN connection unit 4
The frame/token bit string F/TBA output in synchronization with the clock CKT is inputted to generate the symbol string SPT.
Encode and output. 27 is a transmission control unit which inputs the audio data DAT and the symbol string set output from the encoding unit 13, and inserts these into predetermined slots of each frame F output from the reception control unit 24. and output it.

Here, the total number of slots per frame is 1
There are five slots, and the allocation of each slot is determined in advance as follows.

(1) Audio data transmission slot l: mask station 17. - Slave station 17° slot 2 Nislep station 17. -Slave station 17° slot 3
:slave station 17 s-slave station 174 slot 4 nislave station 17. - Master station 17° slot 6: Mask station 17. - Slave station 17 s slot 7: Mask station 1
7. -Slave station 17° slot 9 Nisle station 17t
4 masters [517° slot 10 Nislep station 17t-
I slave station 17° slot 11 slave station 17. →Master station 17° slot 13 Nislep station 17. →Slave station 17° slot 14 Nislep station 17. - Slave station 17° slot 15 Nislep station 174 - Slave station 173 (2) Slot 5, 8.12 for transmitting musical tone control data In such a configuration, each communication station 171 to 174 transmits audio data and musical tone control data. The communication operation will be explained.

First, master station 17. In the packet-switched LAN
Based on the output timing of the transmission control signal TCTL output from the transmission data input section 9 (see FIG. 5) of the connection section 4, the musical tone control data processing section 21 (see FIG. 1) outputs musical tone control data D7 such as a key-on signal. is output and input to the transmission data input section 9 of the packet-switched LAN connection section 4.

Next, in the packet-switched LAN connection section 4, a frame/token bit string F is generated based on the musical tone control data DT.
/After the TBA is generated, this frame/talk Novi 1
CK? It is output in synchronization with
(see figure). For details of the operation of the packet-switched LAN connection section 4, please refer to the specification and drawings attached to Japanese Patent Application No. 1-342291.

The frame/token bit string F/TB is then encoded into a symbol string spy in the encoding section 13 based on the encoding method shown in FIG. 9, and then input to the transmission control section 27.

Next, the symbol string SP is divided and inserted into slots 5.8 and 12 of each frame F generated by the transmission control unit 27.

On the other hand, the 24-bit audio data encoded in the audio data processing section 22 is transmitted to the slave station 17. The audio data to be transmitted to slave station ■7 is divided into slot l of each frame Fh, the audio data to be transmitted to slave station ■7 is divided into slot 6, and the audio data to be transmitted to slave station Llt l74 is divided and inserted into slot 7. be done.

Slots 2-4, 9-11 and 13-15 of each frame F5 are occupied by other slave stations 17°-17. , so a no data symbol (NC) is inserted.

Frame F, in which symbols have been inserted into each slot in this way, is output from the transmission control section 27 and sent to the encoding section 2.
After being encoded into a transmission signal at 3, it is sent to the slave station 17! via connector l and transmission line 18. ~174 periodically.

Next, slave station 17. The decoder 19 decodes the frame F8 from the signal transmitted via the transmission line 18 and the connector 1, outputs it, and inputs it to the circuit-switched LAN connector 15.

Then, in the reception control unit 24, the symbol of the slot assigned to the local station for audio data, in this case, slot l, is IIM 1, in the valley slot y I" l -15 of the input valley frame F5. 1 and a no data symbol (NC
) is inserted.

Further, the extracted symbols are stored one after another in the internal memory of the reception control section 24, and then outputted as audio data DAM in synchronization with the sample synchronization symbol (CS).

Further, in the reception control section 24, the symbols divided and inserted into slots 5, 8 and 12 regarding the musical tone control data of each frame F8 are taken out, and the no data symbol ( NC) is inserted.

Further, the extracted symbols are connected and sequentially output as a symbol string SPR.

Next, the symbol string SPH is decoded into a frame/token bit string F/TBA in the decoding unit 3, and then outputted in synchronization with the clock CK.
Manual power is applied to the Δbe connection part 4.

At this time, if no data symbols (NC) are inserted in slots 5.8 and 12 of each frame, that is, if the master station 17. If information regarding musical tone control data is not transmitted from the decoder 3, the decoder 3 does not output clock CK.

Therefore, the frame/token bit string F/TBA is not input to the packet-switched LAN connection section 4.

When the frame/token bit string F/TBA is input to the packet-switched LAN connection unit 4, the received bit analysis unit 5 (fifth
(see figure), frame/token bit string F/T
A frame bit string FBA constituting a frame of a packet-switched LAN is extracted from BA. Next, in the reception control unit 6, the frame/token bit string F/T
The received data D is extracted from the received data D and is input to the received data output section 7. This reception data D, is the reception control signal 1<CT output from the musical tone control data processing section 21.
Based on L, receive f1. ; The data is outputted from the data output section 7 and input to the musical tone control data processing section 21 for processing.

Here, slave station 17. If it is time to acquire a token and send musical tone control data,
Musical tone control data D7 is output from the musical tone control data processing section 21 based on the transmission control signal TCTL outputted from the transmission data human power section 9 of the packet-switched LAN connection section 4,
The signal is input to the packet/node exchange type LAN connection section 4.

Next, in the packet-switched LAN connection section 4, the musical tone control data D? After a frame bit string FBA is generated based on , it is output in synchronization with the output clock CKt,
The signal is input to the circuit-switched LAN connection section 15 (see FIG. 2).

Also, slave station 17. frame, or
If the timing is such that the token is simply repeated, the packet-switched LAN connection unit 4 outputs the repeated frame/token bit string F/TBA in synchronization with the output clock CKT, and the circuit-switched 1. To N
It is manually connected to the connection part 15 (see FIG. 2).

And Fray 1. /token bit string F/T
After B is encoded into a symbol sequence srT in the encoding section 13, it is manually inputted to the transmission control section 27.

Next, the symbol string SPT is processed by the transmission control section 27.
It is divided and inserted into slots 5.8 and 12 of each frame-F.

On the other hand, slave station 17. If it is not the timing to output the frame/token bit string F/TBA, the packet switching type LAN connection section 4 outputs the frame/token bit string F/TBA to
CKT is not issued.

Therefore, since the symbol sequence sPT is not output from the encoding unit 13, the transmission control unit 27
, no data symbols (NC) remain inserted in slots 5, 8, and 12 of .

Also, slave station 17. At each communication station 17° and 17. ．． 17. Audio data D to be sent to
If there is AT, this audio data DAr is
The audio data is output from the audio data processing section 22 and manually inputted to the circuit-switched LAN connection section 15.

Then, the line switching is performed by l, and the transmission control unit 2 of the ΔN connection unit 15
7, in each slot of each frame F output from the reception control unit 24, the slave station 17. Audio data 1) A to be transmitted to slot 2 is transmitted to slave station 17. The audio data to be sent to slot 10
Then, audio data to be transmitted to the mask station 171 is divided into slots 9 and inserted.

On the other hand, slave station 17. At each communication station +7° and 17. ．． 17. Audio data D to be sent to
A? If not, slot 2.9 of each frame F,
and 10, no data symbols (NC) remain inserted.

Frame F, in which symbols have been inserted into each slot in this way, is output from the transmission control section 27 and is sent to the encoding section 2.
After being encoded into a transmission signal at the communication station 17 . ．． 17. and 17
．． It is sent to L;.

Communication station 17 explained above. The operation in each communication station 1
7. and 174 are also performed in the same way, so the explanation thereof will be omitted.

Then, master station 17. Frame F8 encoded and transmitted from the mask station 17.
When input to master station 17. The above-described reception processing and transmission processing are also performed in , and the frame Fs is encoded and transmitted again.

The operation explained above is performed by each communication station 17. ~17. By repeating this process, musical tone control data and audio data are communicated using one transmission path 18.

By the way, mask station 17. If there is an abnormality in a certain slot of the frame Fs collected at the mask station 17. Then, a data error symbol (ER) shown in FIG. 9 is inserted into that slot and the frame is transmitted.

In addition, each communication station 17. ~17. If the transmitting buffer corresponding to a certain slot of the frame F8 transmitted in the frame F8 overflows, six messages (5 stations 17, 17.
Then, an overflow symbol (OV) shown in FIG. 9 is inserted into that slot, and frame F is transmitted.

Next, when the above-mentioned communication is being performed, for example, the first
Communication 8173 and communication station 17 in the figure. A failure recovery operation when a communication failure occurs, such as a disconnection of the transmission line 18 for some reason, will be described.

In order to manage each communication station in a ring-shaped packet-switched LAN, the applicant has developed a communication station management system in which each communication station knows the address of its upstream adjacent communication station (hereinafter referred to as upstream adjacent station address). We previously jointly proposed a method (see the specification and drawings attached to Japanese Patent Application No. 1-342293).

Here, this communication station management method will be explained.

First, a masked station (hereinafter referred to as an active monitor) sends a special frame (hereinafter referred to as Δ
M l) Frame) woe = believe.

On the other hand, each downstream communication station (hereinafter referred to as a standby monitor) imports the address in the received AMP frame into its own station, replaces that address with its own address, and sends an MP frame to the next station. .

And the active monitor shows A who has gone around the ring.
Collects the MP frame and imports the address in the AMP frame into its own station.

According to the method described above, each communication station can always know the address of an upstream adjacent station.

By the way, if a certain standby monitor cannot receive the above-mentioned AMP frame within a certain period of time, the standby monitor detects that the active monitor is not operating normally.

In this case, the standby monitor that has detected an abnormality in the active monitor forcibly transmits a special frame (hereinafter referred to as a claim token frame) that is issued when the active monitor cannot be detected.

From this C2, the active monitor that has received the claim token frame stops being an active monitor. When all communication stations including this active monitor receive the claim token frame, they participate in the competition for selecting a new active monitor.

Next, the new active monitor selected through the above-described competition restores the ring by purging the ring. In this purge process, the active monitor detects abnormal tokens or frames that have been transmitted on the ring for one or more rounds, removes them, and generates and transmits new tokens. Then, other communication stations synchronize with this, thereby initializing the ring. The processing in the standby monitor described above is called claim token processing.

In addition, if the active monitor detects an abnormality, for example, if it detects an abnormal token or frame as described above, or if it does not detect a normal token or frame within a certain period of time, it performs the purge process described above. , restore the ring.

However, if the ring is not restored by the purge process, the process proceeds directly to the claim token process.

Furthermore, if the ring does not change due to claim token processing, the process moves to beacon processing.

In this beacon processing, first, a communication station that has detected an abnormality generates and transmits a frame (hereinafter referred to as a beacon frame) for notifying the location of the abnormality and its cause. Then, the communication station that has received the normal peakon frame exits the beacon process, and only the communication station that has detected an abnormality with the upstream adjacent station remains. This makes it possible to identify the location of the abnormality and control the separation of the communication station with the abnormality from the ring. Then, the ring may be restored when the abnormal communication station leaves the ring automatically or according to instructions from the user of the communication station.

In addition, normally, the detection period of abnormality by active monitor is 1 fl.
Although the detection period of an abnormality is shorter than that of the standby monitor, the active monitor detects 5 to 50% of the time.

Therefore, even in a LAN where this stream data and commands can be communicated through one transmission path,
The above-mentioned concept of communication failure recovery is adopted.

Normally, when normal communication is being performed, the slave station simply repeats frame F5 transmitted from the mask station or the upstream adjacent station, and performs reception processing and transmission processing at that time. Further, the clock CKT output from the packet-switched LAN connection section 4 of the slave station is the bit clock CK extracted by the PLL circuit section in the decoding section 3 of the circuit-switched LAN connection section 15.

However, when the slave station detects the abnormality using the method described above, the transmission control unit 27 detects the transmitted frame F.
8, it generates its own frame and sends this frame to the packet-switched LAN connection 4.
Forcibly transmits in synchronization with the internal crystal oscillated clock signal. At this time, this frame 1 has the frame t output from the bucket father exchange 1 (9L, AN f?
・Insert the symbols encoded with the token bit string F/TBA into the corresponding slots. From now on, the bucket is exchangeable! The LAN connection unit 4 has a 1-interrupted failure +++ function to recover from the failure and rebuild the network.

As explained above, failure 1 of bucket-swappable AN!
By using the old function, even if there is a failure in l,AN, the freight will be transmitted, so there is no need to consider communication stoppage. In addition, circuit-switched LANs do not have a failure recovery function.
The connection portion I5 can be used as is.

In addition, maintenance of the entire LAN is done using a bucket-replaceable LA.
This is performed using the frame FB input and output to the N connection unit 4.

Further, in the above description, the convex slot of the frame input/output to the line-switched LAN connection unit 15 is referred to as the convex slot.

Although an example is shown in which frames are set in advance, these changes can be made using a frame FBA that is output to the packet-switched LAN connection section 4. By doing this, the six communication stations 17, to 17. Appropriate measures can be taken in response to changing communication demands.

(2) Explanation of the second way of thinking A self-synchronized signal in which a clock is superimposed on data is used as the signal transmitted through the transmission line, and the encoding method for (0/l level) commands and stream data is , in order to mix the two, an encoding method is used in which one symbol is represented by three bits. In this case, if framing data is also encoded, communication efficiency will decrease. for example,
Since 2 bits are required to express the three states of data (O), data (1), and framing data, the communication efficiency is reduced to 1/2. However, there are not many types of data for framing, so if 4-bit data is expressed in 5-bits, the decrease in communication efficiency will be reduced.
It can be suppressed to 415.

Here, an example of the encoding method described above is shown in FIG.

In this figure, 10 indicates that the polarity is reversed, and - indicates that the polarity is not reversed. Also, (ND) is a symbol (
(hereinafter referred to as a no-data symbol).

Next, the data will be converted into bit frames according to the format shown in FIG. 13 and transmitted. This bit frame is of undefined length and has a bit string starting synchronization symbol (BS).
It starts with , and consists of a bit string consisting of (PO), (PI), (So), (Sl), and (ND). A preamble (PRA) is inserted between bit frames, and the end of the bit string is detected by detecting the preamble (PRA).

Further, a bit string start synchronization symbol (BS) is periodically inserted to enable bit synchronization.

Note that since the symbols are in bit units, the position within the bit frame does not matter as long as the order of the symbols matches the original data.

By the way, the following two processing procedures can be considered for generating and recovering bit frames.

The first processing procedure involves generating and collecting bit frames between adjacent stations, but not repeating the bit frames. In the case of this processing procedure, each communication station collects the bit frame transmitted from the upstream neighboring station, generates a new bit frame, and sends it to the downstream neighboring station using the clock oscillating in the own station. Transmit. At that time,
Each station captures data symbols from the received bit frame, and writes data symbols to be transmitted by the station into the bit frame to be transmitted. If there is no data, /-data symbol (
ND).

In the second processing procedure, similar to the first concept described above, the mask station generates and collects bit frames, and the slave station repeats the bit frames and performs reception processing and transmission processing.

Further, although any protocol may be used for the circuit-switched LAN, in the following explanation, the protocol used in the first concept described above will be used.

An embodiment of the second concept will be described below with reference to the drawings. Here, consider audio data as stream data and musical tone control data as commands.

b) Description of an embodiment using the first processing procedure First, it is assumed that the configuration of the ring type LAN is the same as that shown in FIG. However, there is no distinction between mask stations and slave stations, and each communication station generates and transmits a bit frame.

Next, FIG. 3 shows a schematic diagram of the configuration of the communication station 17. In this figure, parts corresponding to those in FIG. 2 are given the same reference numerals, and their explanations will be omitted. In FIG. 3, 28 is a connector connected to the transmission line 18 disposed between the upstream adjacent station, and 29 is a decoding unit, which decodes the signals transmitted via the transmission line 18 and the connector 28. The bit string start synchronization symbol (BS) is detected by decoding the node string, and the bit string frame F is generated. is output in synchronization with the bit string start synchronization symbol (BS).

Further, 30 is a shunt filter, which inputs the two frames F1, extracts only the symbols for the packet, 1 and 1 and 1 and 2 and 2 and outputs a new symbol string SPR. 31 is a decoding unit, which input symbol string S
pe is decoded into a packet-switched LAN frame/token bit string F/TBA and output to the packet-switched LAN connection section 4. Reference numeral 32 denotes an encoding section, which inputs the frame/token bit string F/TBA output from the packet-switched LAN connection section 4, encodes it into a symbol string 5IIT, and outputs it.

Furthermore, 33 is a shunt, which inputs the bit frame F, extracts only the symbols for the circuit-switched LAN, and generates and outputs a new symbol string 581I. 34 is a circuit-switched LAN connection unit, which inputs the symbol string S sm and outputs the symbol string S8- by a predetermined processing procedure.
Processing and replacement are performed on the row (X1) and outputs a new symbol string SsT. 35 is an audio data processing unit, which processes the audio data DA output by the circuit-switched LAN connection unit 34.
- processing and processing of audio data DAT to be transmitted to other communication stations 17;

In addition, 36 is a confluencer, 37 is an encoder ζ, and the streamer 36 temporarily stores the symbol strings SPT and S,1 in the internal memory at the 111th position of the input symbol.

Then, when the symbol request signal SaQ output from the encoding section 37 is manually input, the symbol strings SPT and Ss7 are taken out from the memory and output. At this time, if there are no symbol strings Srt and S8T in the memory (X), a no data symbol (ND) is output.
sT is input to generate a bit frame F in which a bit string start synchronization symbol (BS) is periodically inserted, and the bit frame F is encoded into a transmission signal and sent to the connector 38.
and transmits via the transmission path 18.

In such a configuration, each communication station 17. The operation of communication of audio data and musical tone control data by 174 will be explained.

First, communication station 17. , a key-on signal is generated from the musical tone control data processing section 21 (see FIG. 3) based on the output timing of the transmission control signal TCTL output from the transmission data input section 9 (see FIG. 5) of the packet-switched LAN connection section 4. Musical tone control data DT such as, etc. is output and input to the transmission data input section 9 of the packet-switched type I, ΔN connection section 4.

Next, in the packet-switched LAN connection section 4, a frame/token bit string F is generated based on the musical tone control data DT.
/TBA is generated, this frame/token bit string F/TDA is sent to the bucket switching type LAN connection unit 4.
The signal is outputted in synchronization with the output clock GK'r of the encoder 32, and inputted manually to the encoding section 32.

Then, the frame/token bit string F/TB6 is encoded into a symbol string sp in the encoding unit 32 based on the encoding method shown in FIG. Temporarily stored in memory.

On the other hand, the 24-bit audio data DAT is output from the audio data processing section 35 and sent to the circuit-switched LA.
The symbol string SS? After being encoded into the merger 3
6 and is temporarily stored in the internal memory in units of bits and nodes.

Next, when the symbol request signal 5llQ output from the encoding section 37 is inputted to the combiner 36, the symbol strings SPT and SST are taken out from the memory and output. At this time, the symbol strings SPT and Sl are stored in the memory.
If there is no data symbol (
ND) is output.

Then, the encoding unit 37 generates a bit frame F in which a bit string start synchronization symbol (BS) synchronized with an internally oscillated clock based on the symbol strings S, A, and 5IIT is periodically inserted. The generated bit frame F is encoded into a transmission signal and sent to the connector 3.
8 and transmission line 18.

Next, communication station 17. In the decoding unit 29 of the transmission line 18
A symbol string is decoded from the signal transmitted via the connector 28. Then, a bit string start synchronization symbol (BS) is detected from the symbol string, and is output as a bit frame Fa in synchronization with the bit string start synchronization symbol (BS), and is manually inputted to the shunts 30 and 33.

Then, in the shunt filter 30, only the symbols for the packet-switched LAN are extracted from the bit frame F, and a new symbol string SP is generated.

This symbol string SPR is converted into a packet-switched LAN frame/token bit string F/T in the decoding unit 31.
It is decoded and outputted to the BA, and then input to the port-switched LAN connection section 4.

Next, in the received bit analysis section 5 of the packet-switched LAN connection section 4, the frame/token bit string F/TBA is
A frame bit string FBA constituting a frame of a packet-switched LAN is extracted from the frame bit string FBA.

Next, the reception control unit 6 extracts the reception data D from the frame/token bit string F/TBA and inputs it to the reception data output unit 7. This received data D3 is
Based on the reception control signal RCTL outputted from the musical tone control data processing section 21, the received data output section 7 outputs the received data and inputs it to the musical tone control data processing section 21 for processing.

Here, if it is time for the communication station 17□ to acquire a token and transmit musical tone control data, the transmission data input section 9 of the A/N connection section 4 uses the packet exchange type.
Musical tone control data DT is outputted from the musical tone control data processing section 2I based on the transmission control signal TCTL outputted from the TCTL, and is inputted to the packet switching type I2AN connection section 4.

Next, packet switching type 1. At the A/N connection part 4,
Frame bit string FBA based on musical tone control data DT
After being generated, it is output in synchronization with the ratio clock CK, and is input to the encoding section 32.

Also, communication station 17. When the frame or token is simply repeated, the packet-switched LAN connection section 4 outputs the repeated frame/token bit string F/TB as the output clock C.
It is output in synchronization with KT and input to the encoding section 32.

Then, the frame/token bit string F/TB is encoded into a symbol string SPT by the encoding unit 32, and then input to the combiner 36 and temporarily stored in an internal memory in units of bits.

Also, communication station 17. If it is not the timing to output the frame/token bit string F/TBA,
Output clock 7 clock CK from packet-switched LAN connection section 4
Since T is not output, the symbol string SPT is not output from the encoding unit 32.

On the other hand, in the shunt 33, only symbols for the circuit-switched LAN are extracted from the bit frame F1 to generate a new symbol string 5slI, and this symbol string S□ is input to the circuit-switched LAN connection section 34. .

Then, in the circuit-switched LAN connection section 34, audio data DAII addressed to the own station is extracted from the symbol string S□ according to a predetermined processing procedure and outputted to the audio data processing section 35. The audio data processing unit 35 also includes each communication station 171 and 17. ．． 17. If there is audio data DAT to be transmitted to, this audio data DAT is output from the audio data processing unit 35 and input to the line-switched AN connection unit 34, and the audio data I), A A new symbol sequence S, □ is generated following J yo to 'l, and merges ``I!43
6 and temporarily stored in the internal memory in bit units.

Also, communication station 17. At each communication station 17. and 17
．． ．． 17. If there is no audio data DA to be transmitted, the symbol string S is not output from the circuit-switched LAN connection section 34.

Next, in the combiner 36, the symbol request signal S@ is output from the encoding unit 37. is input, the symbol string SP? is input from memory. and Ss? is extracted and output. At this time, the symbol strings S, 7 and S&” are stored in the memory.
If there is no data symbol (ND), a no data symbol (ND) is output.

Then, the encoding unit 37 generates a bit frame F in which a bit string start synchronization symbol (BS) synchronized with an internally oscillated clock is periodically inserted based on the symbol strings SP'r and S9T, The bit frame F8 is encoded into a transmission signal and sent to the connector 3.
8 and transmission line 18.

2) Communication station explained +7. The operation in 6 communication stations + 7. and 17. This is also done in the same way, so the explanation thereof will be omitted.

The operation explained above is performed by each communication station 17. ~17. By repeating this process, musical tone control data and audio data are communicated using one transmission path 18.

Note that in the embodiment described above, each of the communication stations 17 to 17.
are bit frames F
, for example, the communication station 17. If the clock frequency of the communication station 174 is the highest (and the clock frequency of the communication station 174 is the lowest), data may become clogged at the input section of the communication station 17. However, in this case, each communication station By providing data buffers in 17. to 174, the length of each bit frame F may be adjusted.

(ii) Description of one embodiment of the second processing procedure First, it is assumed that the configuration of the ring type LAN is the same as that shown in FIG. Therefore, the communication station 17+ is a mask station that periodically transmits and collects frames, and the communication station 17. 174 are slave stations that perform reception processing and transmission processing while repeating frames. Also, mask station 17. The configuration is the same as that in FIG.

Next, FIG. 4 shows the slave station 17. ~17. A block diagram of the configuration is shown. In this figure, parts corresponding to those in FIG. 3 are given the same reference numerals, and their explanations will be omitted. In FIG. 4, 39 is a shunt, and the bit frame F
8 manually to extract only the symbols for the packet-switched LAN, generate and output a symbol string S□, and also generate a no data symbol (ND) instead of the extracted symbol.
A new bit frame F', into which is inserted, is output.

Further, 40 is a shunt, and a bit frame F.

It inputs the circuit-switched type [, AN symbol only, generates and outputs a symbol string Ss*, and also outputs a no data symbol (ND) instead of the extracted symbol.
A new bit frame F1b with the inserted bit frame F1b is output.

To Sarah, 41 is a merger and Jimvolta'l S +
7 and Sliding are manually stored in the internal memory in bit units. Then, the bit frame F
D) is detected, its no data symbol (ND)
The symbol strings SPT and S'r are replaced with the extracted symbol strings SI"r and s5T from the memory, and a new bit string SA is output. At this time, if the symbol strings SP? and SSt are not in the memory, In this case, the bit frame F1a is output as is as a bit string SA.

In addition, 42 is an encoding section which inputs the bit string SA output from the confluencer 41, encodes the bit string SA into a transmission signal, and transmits it via the connector 38 and the transmission line 18.

In such a configuration, each communication station 17. The operation of communication of audio data and musical tone control data by 174 will be explained.

First, mask station 17 in FIG. In, Pake.

Based on the output timing of the transmission control signal TCT L outputted from the transmission data input section 9 (connected in FIG. 5) of the switchable LAN connection section 4, the musical tone control data processing section 21 outputs musical tone control data such as a key-on signal. The data is output and input to the transmission data input section 9 of the packet-switched LAN connection section 4.

Next, in the packet-switched LAN connection section 4, a frame/token bit string F is generated based on the musical tone control data DT.
After /TBA is generated, this frame/token bit string F/TBA is outputted in synchronization with the output signal CKt of the packet-switched LAN connection section 4 and inputted to the encoding section 32.

Then, the frame/token bit string F/TB is encoded into a symbol string SPA in the encoding section 32 based on the encoding method shown in FIG. Temporarily stored in internal memory in units.

On the other hand, the 24-bit audio data DAT is output from the audio data processing section 35 and sent to the circuit-switched LAN.
After being manually inputted to the connecting unit 34 and encoded into a symbol string SST based on the encoding method shown in FIG.
6, and is temporarily stored in the internal memory at 1st place (beep).

Next, in the combiner 36, the symbol request signal SA output from the encoding section 37 is received. is input, the symbol string S P? is input from the memory. and SsT are extracted and output. At this time, the symbol strings S, 7 and S, 7 are stored in the memory.
If there is no data symbol (ND), a no data symbol (ND) is output.

Then, in the encoding unit 37, the symbol string S, ? A bit frame F is generated in which a bit string start synchronization symbol (BS) synchronized with an internally oscillated clock is periodically inserted based on Sl, and the bit frame F is encoded into a transmission signal and 38 and transmission line 18.

Next +, -1 Slave station 17 in Figure 4. 1, the symbol string is decoded from the signal transmitted via the transmission path 18 and the connector 28, a bit string start synchronization symbol (BS) is detected from the symbol string, and a bit string is generated as a bit frame F. Starting sync symbol (B
S) is outputted in synchronization with S) and inputted to the flow divider 39.

Then, in the shunt 39, only the symbols for the packet-switched LAN are extracted from the bit frame F, a new symbol string 5PII is generated and output, and the Nino data symbol (
A new bit frame F' into which ND) is inserted is output.

Next, the operation from when the symbol string S pt is input to the decoding section 31 to when the symbol string SPT output from the encoding section 32 is input to the merging WA 41 and temporarily stored in the internal memory is as described above. After the symbol string 5PII explained in the processing procedure 1 is input to the decoding section 31, the symbol string SPT output from the encoding section 32 is input to the confluencer 36.
Since the operation is the same as that from input to the internal memory until it is temporarily stored in the internal memory, the explanation thereof will be omitted.

On the other hand, in the shunt 40, the bit frame F.

. A new symbol string S1.1i is generated by extracting only the circuit-switched LAN symbols from・lt frame F'
−°ゎ is output, then the symbol sequence S, k is circuit-switched IQ, l, ΔN
The operation from when the symbol strings S and l are input to the connection unit 34 until they are input to the confluencer 41 and temporarily stored in the internal memory is as follows: Replaceable type 1. Since the operation is the same as that from when the symbol string SIT is input to the AN connection unit 34 until it is input to the confluencer 36 and temporarily stored in the internal memory, the explanation thereof will be omitted.

Next, the bit frame F°°8 outputted from the shunt filter 40 is input to the confluencer 41, and the bit frame F l 1 . When a no data symbol (ND) is detected from the memory, the symbol strings SPa and Sl are taken out from the memory, and the symbol strings SP? and S,? is replaced with a no data symbol (ND). As a result, the symbol string SA is output from the confluence 641. At this time, if the symbol strings spy and Ssr do not exist in the memory, the bit frame l・F'' is changed to the symbol string SA as it is.
is output as

Then, when the symbol string S is inputted to the encoding unit 42, the symbol string SA is transmitted rtj (+'!
The data is encoded into a code and transmitted via the connector 38 and the transmission line 18.

Communication station 17 explained above. The operation in Kodoshin Bureau 1
7. and 17. This is also done in the same way, so the explanation thereof will be omitted.

Then, master station 17. The bit frame F encoded and transmitted from the mask station 17 . , the mask station 17°1 also performs the above-described reception processing and transmission processing, and the bit frame Fl is encoded and transmitted again.

The operation explained above is performed by each communication station 17. -17. By repeating this process, musical tone control data and audio data are communicated using one transmission path 18.

Note that the LAN fault iq old operation explained in the first concept above is similar to the ring LAN according to the second concept.
It can also be applied to

In addition, the LAN according to the first and second processing procedures described above
In the embodiment, an example was shown in which the configuration shown in FIG. 5 was used as the packet-switched LAN connection section 4, but the present invention is not limited to this. In other words, a ring-shaped bucket exchangeable LAN
Any type of material may be used as long as it is used in

Furthermore, LA according to the first and second processing procedures described above
In the embodiment N, each communication station 17 has a packet-switched L
Although an example has been shown in which there is one each of the AN connection section 4 and the line-switched LAN connection section 34, the present invention is not limited to this, and more LAN connection sections may be connected.

In addition, in the embodiment of the LAN according to the first processing procedure described above, the bit frame F has an undefined length, and the end of the bit frame Fa is detected by detecting the preamble (PRA). , bit frame F
, to a fixed length and pit Wll starting synchronization symbol CB
After S), the end of bit frame F8 may be detected by detecting a preset number of bits. Furthermore, even if the bit frame F11 has an undefined length, by encoding a symbol indicating the end of the bit frame Fs, the end of the bit frame F can be detected by detecting this symbol. good.

Furthermore, in all of the embodiments described above, since the previously proposed packet-switched LAN connection unit is used, an example is shown in which commands and stream data are transmitted through separate LAN connection units, but the present invention is not limited to this. . That is, since it is sufficient that commands and stream data can be transmitted through one LAN, commands and stream data may be transmitted through one LAN connection section.

"Effects of the Invention" As explained above, according to the present invention, stream data and commands can be communicated over one LAN with a simple configuration and protocol without reducing communication efficiency. .

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of a ring type ■ and ΔN according to an example in which the first and second concepts are applied, and Figure 2 is a communication diagram according to an example in which the first concept is applied. station 1
7 is a block diagram showing the configuration of the communication station 17 according to an embodiment using the first processing procedure of the second concept, and FIG. FIG. 5 is a block diagram showing an example of the configuration of a slave station 17 according to an embodiment using the second processing procedure. FIG. The figure shows an example of the structure of a frame based on the first concept, and Figure 7 shows a ring type L to which the first concept is applied.
A diagram showing an example of the configuration of a control unit for transmitting and receiving signals of an AN, FIG. 8 is a diagram showing an example of the configuration of a control unit for transmitting and receiving signals of a ring type LAN to which the second concept is applied, and FIG. 10 is a diagram showing an example of the data archiving method according to the first concept, Figure 1O is a diagram showing an example of the frame structure according to the first concept, and Figure 11 is a diagram showing an example of the data archiving method according to the first concept. FIG. 12 is a diagram showing an example of a data encoding method according to the second concept, and FIG. 13 is a diagram showing an example of a bit frame configuration according to the second concept. 1.28.38... Funecta, 3.19,29
゜31...Decoding section, 4...Packet switching type LAN connection section, 13.23, 32.37.42...
... Encoding section, 15.34 ... Circuit switched LAN connection section, 17, ~174 ... Communication station, 1
8...Transmission line, 21...Music tone control data processing section, 22゜35......Audio data processing section, 24...Reception control section,... ...Transmission control section, 30゜33゜39゜0 ...... shunt, 36゜1 ...... merger.

Claims (1)

[Scope of Claims] In a ring-type LAN in which a plurality of communication stations are connected in a ring shape through a transmission path and data communication is performed between these stations, the plurality of communication stations are configured to perform musical tone control such as a key-on signal or a key-off signal. A ring type LAN characterized in that data and audio data are encoded into symbols using the same encoding method, frames are generated using the symbols, and the frames are transmitted using the transmission path.