JP2002111720A - Data transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit data within a short period without increasing of the physical wiring route and also effectively transmit data through the centralized error management. SOLUTION: A host terminal 10 and a plurality of client terminals 1 to 7 are connected with the ISDN link through the desired connection routes. Moreover, the host terminal 10 and each client 1 to 7 are given regional information such as a telephone number. Based on this regional information, the host terminal 10 and each client terminal 1 to 7 are connected through the daisy chain connection method depending on the regional sequence as illustrated in the Fig. Accordingly, the host terminal 10 distributes block data to the most significant client terminals 2, 3 in the daisy chain system. Subsequently, the client terminals 2, 3 sequentially distribute the block data to the client terminals 4, 5 of the next significant clients 4, 5. The host terminal 10 obtains a distribution result of each client terminal through the inverse route.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data transmission system for distributing data from a host terminal to a client terminal through a network, and more particularly, to a host terminal for distributing data to be displayed and a plurality of terminals for receiving the distributed data. The present invention relates to a data transmission system for efficiently distributing data such as contents in a system constituted by client terminals.

[0002]

2. Description of the Related Art An information display comprising a host distribution device (hereinafter, referred to as a host terminal) for distributing data and a plurality of information display terminals (hereinafter, referred to as client terminals) for receiving and displaying the distributed data. In a system, when data is distributed from a host terminal to many client terminals via a network, various data transmission systems are conventionally known.

For example, there is a system in which a host terminal and each client terminal are connected one-to-one via a network, and data is transmitted from the host device to each client terminal. In this transmission system, after data has been transmitted to one client terminal, data is transmitted to undistributed client terminals, and such data transmission is repeated until there is no client terminal to receive.

In this case, a data transmission network in this case is a transmission using a modem via a public network, a TA (Terminal Adapter) or a DSU (Digita).
l ISDN (Integrated S via Service Unit)
ervices Digital Network) transmission via a line, transmission using a dedicated line network, LAN
(Local Area Network) or the like, and transmission via an in-house network, or transmission via a LAN, so-called Internet. At this time, each network may be physically connected one-to-one or logically one-to-one, but the data transmission is performed in the same manner in any connection. is there.

As another data transmission method, there is a method in which a host terminal and each client terminal are connected one to n to transmit data. In this case, the host terminal and each client terminal are connected in parallel, and data is transmitted from the host terminal to each client terminal on the receiving side. In order to adopt such a transmission method, each client terminal needs to be physically or logically connected in parallel. This transmission method is a transmission method applicable to only one-way communication.

Japanese Patent Application Laid-Open No. 11-17712 discloses a technique in which a master station specifies a transmission order and transmits the data to a plurality of slave stations. According to this technology,
The master station transmits a batch transmission frame including the transmission order specification to a plurality of slave stations, and each slave station receiving the transmission frame transmits a response frame of a slave station earlier than its own station based on the transmission order specification. Each time it is completed, it continuously transmits to the master station. According to such a transmission method, the idle time during which each slave station is not transmitting data to the master station can be reduced, so that transmission efficiency can be increased within a limited band.

[0007]

However, the conventional data transmission method as described above has various problems as described below. That is, a method of connecting the host terminal that distributes data and the client terminal that receives and displays this data on a one-to-one basis is that the host terminal transmits data to the next client terminal at the end of transmission for each client terminal. To start, the delivery time is long. In order to end distribution in a short time, it is necessary to execute distribution processing from the host terminal to many client terminals at the same time, but in order to perform many distribution processing at the same time, the number of physical or logical ports is required. It is necessary to prepare more than one. In particular, in order to increase the number of physical ports, it is necessary to prepare not only the number of ports of the host terminal but also a plurality of network paths, which requires a great deal of cost.

Also, by increasing the number of logical ports via the LAN, data can be distributed to a plurality of client terminals at the same time. However, depending on the number of ports, the processing capacity of the host device for distributing data can be increased. In addition, the transmission speed may be delayed due to the transmission capability of the data transmission transmission line, and as a result, the transmission efficiency may be reduced.
Furthermore, when the band of the transmission path becomes congested and there is another device sharing the same transmission line, a problem such as a delay in data transmission of the other device may occur.

On the other hand, the method of connecting the host terminal and the client terminal in a one-to-n manner has an advantage that data transmission can be performed collectively because each client terminal and the host terminal are connected in parallel. In order to transmit data, it is necessary to physically prepare a large number of distribution transmission lines and data output ports themselves, which increases the cost of the apparatus. As a transmission method for reducing the number of transmission paths and output ports, there is a transmission in a broadcast format. However, this transmission method is only one-way transmission, and it is impossible for the host terminal that has delivered the data to confirm whether the client terminal has successfully received the data. Therefore, in order to surely confirm whether or not all data has been normally received at the client terminal, it is necessary to inquire the distribution result from the host terminal side to each client terminal after distributing all data. .

In short, regardless of whether the host terminal and the client terminal are connected one-to-one or one-to-n, data transmission efficiency is taken into consideration when data is distributed from the host terminal to the client terminal. Since the distribution route is not determined by this method, when data is transmitted via the ISDN line, problems such as an increase in communication cost and distribution time occur. In addition, when data transmission is performed using a dedicated line network, problems such as an increase in distribution time occur.

Further, in the technique disclosed in Japanese Patent Application Laid-Open No. 11-17712, the master station transmits a collective frame to a plurality of slave stations. Therefore, as the number of slave stations increases, the number of distribution transmission lines and data output ports increases. The problem of becoming is still not solved. That is, in the conventional data transmission method, devices such as wiring routes are expensive, data distribution takes a long time, error correction of transmission data cannot be performed, and furthermore, data transmission routes cannot be corrected. There is a possibility that a problem such as causing the transmission band to be in a congested state may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to suppress the transmission band of a transmission path in a relatively short time without increasing the number of physical wiring paths. It is another object of the present invention to provide a data transmission system capable of transmitting data efficiently and at a low cost by enabling centralized management of errors.

[0013]

In order to solve the above-mentioned problems, a data transmission system according to the present invention is a data transmission system for distributing data from a host distribution device to a plurality of terminal devices via a network. The host distribution device and the plurality of terminal devices are connected in a daisy chain system, the host distribution device includes a block dividing unit that divides data to be distributed into blocks, and further, the host distribution device and the plurality of terminal devices are In addition, area information for specifying the area where each is installed is given. Then, according to the daisy-chain method, when data is distributed in block units from the upper terminal device to the lower terminal device sequentially, based on the local information given to the host distribution device and each of the plurality of terminal devices, It is characterized in that it is configured to select a distribution route that minimizes the communication line fee and distribute data.

According to the data transmission system of the present invention, the block-based data distributed from the host distribution device to each terminal device is transferred from the higher-level terminal device to the lower-level terminal device sequentially, while the target terminal device is transmitted. Delivered to Further, the reception result is notified to the host distribution device via a route reverse to the above-described distribution route. For this reason, even if there are many terminal devices, data can be distributed to all terminal devices via a small number of transmission paths, and a data transmission system with a small number of ports and transmission lines can be constructed. Further, based on regional information such as telephone numbers assigned to the host distribution device and each terminal device, an optimal distribution route is selected in the order of, for example, regions closer to each other. Therefore, the data transmission time can be greatly reduced, and the communication cost can be significantly reduced when the data is transmitted via the ISDN line.

Further, in the data transmission system according to the present invention, in addition to the above-described invention, the host distribution device manages the data reception status of each of the plurality of terminal devices, and manages each of the plurality of terminal devices. A diagnostic command for confirming the connection status of the distribution route is transmitted. When reply data to the diagnostic command is returned from at least one of the plurality of terminal devices, the connection of the plurality of terminal devices is performed based on the reply data. It is characterized by grasping the situation and selecting a distribution route so that data can be transmitted via the nearest router. It should be noted that the distribution route can be automatically selected, or if there is a route that generates a large amount of traffic for some reason, the distribution route can be switched to manual and changed. .

According to the data transmission system of the present invention, even when the host distribution device and a plurality of terminal devices are connected by a dedicated network, the host distribution device transmits a diagnostic command to each terminal device. Accordingly, an optimal distribution route can be automatically selected so that data transmission can be performed via the closest router among routers included in each terminal device. Therefore, even in the case of a dedicated line network, it is possible to reduce the communication cost and the data transmission time. In addition, since the host distribution device performs centralized management of the data reception status of each terminal device, it is possible to reduce the data transmission / confirmation time and to use the data transmission band of the distribution route to the minimum necessary. Can be.

Further, in the data transmission system according to the present invention, in addition to the above-mentioned invention, the host distribution device may further include:
A distribution route is displayed on a display screen or the like, and an optimal distribution route is selected based on the displayed distribution route.

According to the data transmission system of the present invention, for example, when a host distribution device and a plurality of terminal devices are connected via a dedicated network, the distribution route can be confirmed on a display screen. Then, it is possible to change the distribution route of a desired terminal device while looking at the distribution route displayed on the screen. In this manner, the screen operation allows the user to select the optimal delivery route while changing the delivery route of the terminal device according to the situation, so that an extremely convenient data transmission system can be constructed.

Further, in the data transmission system according to the present invention, in each of the above-mentioned inventions, each terminal device has a bypass path connecting the respective terminal devices, and when an error occurs in a main transmission path, an error is generated. Data is transmitted to a lower terminal device through a bypass path that bypasses the generated transmission path.

According to the data transmission system of the present invention, even if transmission errors occur frequently or the route of a higher-order terminal device fails, the transmission route of the failed terminal device is cut off and only the relevant portion is deleted. The data can be transmitted to other terminal devices as usual.

According to the data transmission system of the present invention, the connection state of the daisy chain system is configured to be any of LAN, public line, dedicated line, Internet connection, or a combination of these. Can also. Note that it is also possible to connect to these lines via a TA, DSU, or a modem. In other words, it is possible to connect to a LAN, a public line, a dedicated line, the Internet, or the like, which is conventionally used on a daily basis, while appropriately selecting according to the situation, thereby constructing an extremely convenient data transmission system. Can be.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the data transmission method according to the present invention will be described in detail. That is, in the data transmission method of the present invention, the data to be transmitted is subdivided into blocks in advance, and the host terminal, which is the distribution server, sequentially transmits the data to the client terminal, which is the lower display terminal, in a daisy chain system. Distribute block data. The daisy chain system is a system in which a data bus is connected in a daisy chain from an interface of one terminal to an interface of another terminal.

The confirmation of the transmission result performed by the host terminal is performed by notifying the host terminal via the higher-level client terminal when each client terminal receives the block data. For example, when a certain client terminal detects a transmission error, it makes a retransmission request to the client terminal one stage higher than the daisy chain connected client terminal, and repeats this request up to the host terminal. The block data is retransmitted to the client terminal to recover the transmission error. With such a data transmission method, the host terminal performs centralized management of the data reception status of each client terminal. The connection state of the daisy chain at this time may be any of LAN, public line, dedicated line, and Internet connection, and may be connected via a modem. According to such a data transmission method, the data transmission time can be shortened, and the data transmission band of the distribution path can be used at a minimum.

Hereinafter, embodiments will be described in detail with reference to the drawings. FIG. 1 is a connection configuration diagram in which a host terminal and each client terminal are LAN-connected by an ISDN line in the embodiment of the present invention. That is, this connection form diagram
A daisy-chain connection between the host device and each client terminal is realized by a LAN connection. Each of the routers 1a, 2a,... 7a is transmitted from the host terminal 10 via a LAN line via the router 10a as a relay device.
Are connected to the client terminals 1, 2,. Each of the host terminal 10 and the client terminals 1, 2,... 7 has local information such as a telephone number added thereto.

FIG. 2 is a distribution path diagram from the host device to each client terminal in the connection form of the ISDN line of FIG. That is, in the case of the connection form shown in FIG. 1, a daisy-chain delivery route as shown in FIG. 2 is created based on the area information (telephone number). Such a wiring route is configured to be sequentially distributed from a client terminal in a nearby area based on the area information (telephone number) of the host terminal 10. Therefore, as shown in FIG. 2, from the host terminal 10 whose area information is “Tokyo”, one of the routes is in the order of distance from the client terminal 2 (Mito) -client terminal 5 (Sendai) -client terminal 6 (Sapporo). The other route is the client terminal 3 (Nagoya) -the client terminal 4 (Osaka) -the client terminal 1 (Hiroshima) -the client terminal 7 (Fukuoka). In this example, the ISDN line (2B + D)
FIG.

In FIG. 2, the distribution data is distributed in block units from the host terminal 10 to the client terminals 2 and 3 in the nearest area, and thereafter, the data is sequentially distributed from the client terminals in the nearest area. Further, the client terminals 2 and 3 transfer the received block to the lower-level client terminals 4 and 5, and when all the blocks have been received, return the reception result to the higher-level device (host terminal 10). Hereinafter, this procedure is sequentially repeated to transmit data in block units.

That is, in FIG. 2, the host terminal 10
Is distributed to the client terminal 2 from the client terminal 2, the distribution result is returned from the client terminal 2 to the host terminal 10. Further, data is distributed from the client terminal 2 to the client terminal 5, and a distribution result is returned from the client terminal 5 to the host terminal 10 via the client terminal 2. Further, data is distributed from the client terminal 5 to the client terminal 6, and a distribution result is returned from the client terminal 6 to the host terminal 10 via the client terminal 5 and the client terminal 2. On the other hand, in the case of data distributed from the host terminal 10 to the client terminal 3, the client terminal 3-3 has the same procedure as described above.
Data distribution is performed in the order of the client terminal 4 to the client terminal 1 to the client terminal 7, and the distribution result is returned in the reverse order.

On the other hand, in the case of transmission using a dedicated line network in creating a distribution route, a diagnostic command is transmitted from the host terminal to each client terminal, and the connection status of each client terminal from the host terminal (for example, Routers that pass through). Then, based on the collected connection status, the host terminal and each client terminal are sequentially connected, and a distribution route is automatically created. Creation of a distribution route when a dedicated network is used will be described in more detail with reference to the drawings.

FIG. 3 is a connection form diagram in which a host terminal and each client terminal are connected by a dedicated line in the embodiment of the present invention. FIG. 4 is a distribution route diagram when the distribution from the host device to each client terminal is developed in a daisy chain system in the connection form of the dedicated line shown in FIG. That is, in the case of the connection form using the dedicated line as shown in FIG. 3, if the distribution path is created based on the result of the diagnostic command, the distribution path becomes a daisy chain distribution path as shown in FIG.

In FIGS. 3 and 4, A1, B1, C
1, C2, D1, E1, E2, F1, F2, G1, G
2 and G3 indicate client terminals, respectively, and the alphabetical order indicates the order of client terminals located near the host device 20. Therefore, as shown in FIG. 4, the client terminals A1, B1, and C1 are at the top, and the distribution data from the host device 20 is distributed to the client terminals A1, B1, and C1. 27, the data is sequentially distributed to the client terminals from the client terminals located in an area closer to the host device 20 based on the regional information from the routers 21 to 27 that pass through.

That is, in FIG. 4, the distribution data is
Data is distributed from the host terminal 20 to the nearest client terminals A1, B1, and C1 in block units,
Thereafter, the data is sequentially distributed from client terminals located in nearby areas. Further, the client terminals A1, B1, and C1 transfer the received blocks to the lower-level client terminals D1, E1, F1, and C2, respectively. When all the blocks have been received, the reception results are transferred to the host device (host terminal 20). ), And the respective reception results are returned to the host terminal 20 via the higher-level client terminal. Hereinafter, this procedure is sequentially repeated to transmit data in block units.

The automatically created distribution route is displayed on the screen of a personal computer or the like each time, so that the operator can confirm it. Therefore, when it is desired to change the connection of the distribution route created automatically, the distribution route is changed while looking at the distribution route displayed on the screen. That is, FIG. 5 is an example of a display screen showing the distribution route changing method shown in FIG. 4, wherein (a) shows the distribution route display screen before the change, and (b) shows the display screen of the distribution route after the change. Is shown. FIG. 6 is a distribution route diagram when the distribution route is changed as shown in FIG. 5B.

That is, the distribution route shown in FIG.
It is displayed as shown in FIG. In other words, before the change of the distribution route, the client terminals distributed first from the host device are A1, B1, and C1, but the client terminals are C1,
If the number of client terminals less than or equal to 1 is changed to be connected after A1, a display screen of the distribution route as shown in FIG. That is, the client terminals distributed first from the host terminal are A1 and B1, and the client terminals C1 and C2 are displayed so as to come after the client terminal A1. Therefore, when the distribution route is changed as shown in FIG. 5B, the distribution route becomes as shown in FIG. That is, if a screen as shown in FIG. 5B is created while watching the distribution route displayed on the screen of FIG. 5A, the distribution route shown in FIG. Like the distribution route, the client terminals C1 and C2 can be changed to a distribution route that is connected after the client terminal A1.

Next, an operation flow of the data transmission method according to the present invention will be described with reference to a flowchart. FIG.
Is a flowchart showing the flow of the operation of the data transmission method according to the present invention.

[Step S1: Preparation of Distribution Data] First, data to be distributed from the host terminal 10 is prepared. In this case, the data to be distributed is usually composed of a plurality of files. On the side of the host terminal 10 that distributes the data, the data to be distributed is combined into one, and then divided into blocks. Further, after division into blocks, information such as a serial number indicating the order of the blocks and the number of blocks is added.
The size of the unit block is about 1 KB to several hundred KB, and is determined by the transmission band of the transmission path to be used, the processing capacity of the distribution host, and the like. The serial number is assigned to each block unit, and by checking the consistency of the numbers, the data becomes effective data for determining whether the reception result has been properly performed.

[Step S2: Creation of Distribution Route] When data is transmitted via an ISDN line as shown in FIG.
As described above, the distribution order of the client terminals 1, 2,... 7 is sorted by using the local information (telephone numbers and the like) added to the host terminal 10 and the client terminals 1, 2,. Then, based on the sorted order, the host terminal 10 and each of the client terminals 1, 2,... 7 are sequentially daisy-chain connected, and a distribution route as shown in FIG. 2 is automatically created. Further, the automatically created distribution route is displayed on a screen for confirmation. Therefore, when it is desired to change the connection of the distribution route created automatically, the distribution route is changed while looking at the distribution route displayed on the screen.

On the other hand, when transmission is performed using a dedicated line network as shown in FIG. 3, a diagnostic command is transmitted from the host terminal to each client terminal, and the connection status of each client terminal is collected from the host terminal. . Then, the host terminal and each client terminal are sequentially connected based on the collected connection status, and a distribution route as shown in FIG. 4 is automatically created. Further, the automatically created distribution route is displayed on a screen for confirmation. Therefore, when it is desired to change the connection of the distribution route created automatically, the distribution route is changed while looking at the distribution route displayed on the screen. It should be noted that the method of creating a distribution route when a dedicated line network is used is as described above.

[Step S3: Data Distribution] When the distribution route is determined as described above, first, the host terminal distributes a list of files to be distributed and the distribution route. In this case, the blocked data is sequentially distributed to the client terminals according to the distribution route. In other words, the host terminal performs data distribution by dividing the distribution data block into n and dividing it into distribution data blocks in order to divide the distribution-scheduled data into distribution units. It is sequentially distributed to lower-level client terminals. And the lower client terminal is
The reception result is sequentially returned to the host terminal via the higher-level client terminal.

[Step S4: Check for Delivery Error]
The serial number added to the block in advance checks the number consistency with the data received immediately before. If there is no consistency, it is determined that an error has occurred and the host device (host terminal)
A retransmission request is made to. Of course, the lower client terminal sends a retransmission request to the host terminal via the upper client terminal. In addition, regarding the bit consistency of the block,
It shall be detected and corrected on the transmission path protocol. That is, OSI (Open System Interconnectio
Error correction is performed in the data ring layer described in n).

[Step S5: Detection of Distribution End] In the above-described distribution error check in step S4,
The detection of the end of the distribution when the distribution is normally performed is performed based on the transmitted block serial number and the number of blocks. The end of the distribution of all data is checked by checking each file in the distribution file list received by each client terminal first, and when all the distribution is completed, it is determined that the distribution is completed.

[Step S6: Collection of Distribution Result] The distribution result information is collected from lower terminals in the direction opposite to the distribution route. That is, the host terminal sequentially collects the distribution error information from the lower-level client terminals via the higher-level client terminals along a route reverse to the distribution route. For example, in the case of the distribution route shown in FIG.
The distribution result is collected to the host device 10 along the route of the client terminal 6-the client terminal 5-the client terminal 2 and the route of the client terminal 7-the client terminal 1-the client terminal 4-the client terminal 3.

[Step S7: Processing at the Time of Abnormality] In the processing of the above-mentioned distribution error check at step S4, when the distribution is not performed normally, the transmission error occurs in the middle of the distribution path. In this case, the transmission error is reduced by disconnecting the route with the terminal using the route and bypassing the end where the error has occurred. FIG. 8 is a diagram illustrating a distribution state by the bypass route when the normal route is abnormal. That is,
The figure shows that when an abnormality occurs in the path between the upper-level client terminal (N-1) and the immediately lower-level client terminal (N), the client terminal (N-1) becomes the client terminal (N). And a state where data transmission is performed to the lower-level client terminal (N + 1) by bypassing. Therefore, when an abnormality occurs in the route of the higher-level client terminal or the client terminal itself, the route of the client terminal is cut off, and data is distributed to the lower-level client terminal using the bypass route.

As described above, when a distribution error occurs frequently in the check of the distribution data, as shown in FIG. 8, the route of the client terminal (N) using the route in which the error occurred frequently is disconnected. Client terminal (N-
1) The client terminal (N) where the error has occurred
And by transmitting data to the client terminal (N + 1), thereby reducing transmission errors and performing error recovery.

That is, as described above, according to the data transmission method of the present invention, each client terminal is connected in a daisy chain manner with the distribution path starting from the host terminal. When transmission is performed via an ISDN line, local information (for example, a telephone number) is added to the host terminal and each client terminal so that data transmission can be performed with a connection that minimizes communication costs. , Automatically create a wiring route. On the other hand, in the case of transmission using a dedicated network, the host terminal sends a diagnostic command to each client terminal, and automatically routes the wiring so that data can be transmitted via the nearest router. To create.

If there is a route that generates a large amount of traffic due to the existence of another device shared by the same transmission line, the created distribution route is automatically manually set. Make it possible to change the route. Further, before starting the data transmission, the created wiring route is displayed as shown in FIG. 5, and the wiring route can be changed while confirming it.

When there is a client terminal whose data transmission fails for some reason, the data can be distributed by bypassing the client terminal. Furthermore, by creating a distribution route beforehand at the host end, the data reception status at each client end can be centrally managed by the host terminal. Therefore,
With such daisy-chain data distribution, the data transmission time can be reduced,
As for the data transmission band of the distribution route, only the minimum necessary band may be used.

The embodiment described above is an example for describing the present invention, and the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the invention. is there. For example, in the above-described embodiment, a case has been described where lower-level client terminals are sequentially determined from a higher-level client terminal. However, upper-level and lower-level client terminals may be determined from an arbitrary client terminal. it can. The determination method at this time determines an upper-level client terminal and a lower-level client terminal based on an inquiry signal and an answer signal based on data.

[0048]

As described above, according to the data transmission system of the present invention, a data transmission path is created and a data transmission is performed in a daisy chain. It can be performed. Further, an optimal distribution route is selected based on local information such as a telephone number assigned to the host terminal and each client terminal. Therefore, the data transmission time can be greatly reduced, and the ISDN
In the case of transmission via a line, communication costs can be reduced.

Also, because of the daisy chain connection,
Even if there are many lower-level client terminals after a certain route, the amount of data to be transmitted is only for one client terminal, and the data can be transmitted by the data transmission path band for one device. Therefore, the number of interfaces and transmission paths can be reduced, so that cost can be reduced.
Furthermore, the creation of the distribution route can prevent a large amount of traffic that occurs partially in the network. In addition, the result of data transmission can be centrally managed by the host terminal, and an optimal distribution path can be selected while operating the distribution path displayed on the display screen of the host terminal. A transmission system can be provided.

[Brief description of the drawings]

FIG. 1 is a connection form diagram in which a host terminal and each client terminal are LAN-connected by an ISDN line in an embodiment of the present invention.

FIG. 2 is a distribution route diagram from the host device to each client terminal in the connection configuration of the ISDN line in FIG. 1;

FIG. 3 is a connection diagram in which a host terminal and each client terminal are connected by a dedicated network in the embodiment of the present invention.

4 is a distribution route diagram in the case where distribution from the host device to each client terminal is developed in a daisy chain system in the connection form of the dedicated line shown in FIG. 3;

FIG. 5 is an example of a display screen showing the distribution route changing method shown in FIG. 4, wherein (a) shows a distribution route display screen before the change,
(B) is a display screen of the distribution route after the change.

FIG. 6 is a distribution route diagram when the distribution route is changed as shown in FIG. 5 (b).

FIG. 7 is a flowchart showing an operation flow of a data transmission method according to the present invention.

FIG. 8 is a diagram illustrating a distribution state by a bypass route when a normal route is abnormal.

[Explanation of symbols]

1, 2, 3, 4, 5, 6, 7 Client terminal 1a, 2a, 3a, 4a, 5a, 6a, 7a Router 10, 20 Host terminal 21, 22, 23, 24, 25, 26 Router A1, B1, C1, C2, D1, E1, E2, F1, F
2, G1, G2, G3 client terminal

Continued on the front page (72) Inventor Mikio Omata 3-14-20 Higashinakano, Nakano-ku, Tokyo International Electric Co., Ltd. (72) Inventor Takayuki Tsutsui 3-14-20 Higashinakano, Nakano-ku, Tokyo International Electric Co., Ltd. (72) Inventor Shoichiro Miyashita 3-14-20 Higashinakano, Nakano-ku, Tokyo F-term in Kokusai Denki Co., Ltd. (reference) 5K030 GA20 HA08 HD03 LB05 5K033 AA04 BA13 CB08 CC01 DA01 DA05 DA11 DB18

Claims (4)

[Claims] 1. A data transmission system for distributing data from a host distribution device to a plurality of terminal devices via a network, wherein the host distribution device and the plurality of terminal devices are connected in a daisy chain system, The distribution device includes a blocking unit that divides data to be distributed into blocks, and the host distribution device and the plurality of terminal devices are provided with region information that specifies a region where the host device and the plurality of terminal devices are installed. When distributing data in block units from a higher-level terminal device to a lower-level terminal device sequentially according to the chain method, data is distributed by selecting a distribution route that minimizes a communication line fee based on the regional information. A data transmission system configured to perform: 2. The host distribution device manages a data reception status of each of the plurality of terminal devices and transmits a diagnostic command to each of the plurality of terminal devices to confirm a connection status of a distribution path. The connection status of the plurality of terminal devices is grasped based on reply data to the diagnostic command returned from at least one of the plurality of terminal devices, and data transmission is performed via a closest router. 2. The data transmission system according to claim 1, wherein a distribution route is selected so that the data transmission can be performed. 3. The host distribution device displays a distribution path before distributing data in block units to each of the plurality of terminal devices, and determines an optimal distribution path based on the displayed distribution path. 3. The data transmission system according to claim 1, wherein the data transmission system is selected. 4. Each of the plurality of terminal devices includes a bypass path connecting the respective terminal devices,
4. The method according to claim 1, wherein when an error occurs in a main transmission path, data is transmitted to a lower terminal device through a bypass path that bypasses the transmission path in which the error has occurred. Data transmission system.