JPH04263545A - Data communication equipment - Google Patents

Abstract

PURPOSE:To prevent a line from being occupied for a long time even in the case of transmitting the large capacity of file data in data communication. CONSTITUTION:A file transmission control part 1c of a transmission side node 1 receiving a file transmission response 13 requests the read of a file data 18 stored in a storage medium 1a to a file read control part 1b. At such a time, when the data 18 stored in the storage medium 1a can not be read by the request of one time of reading since the capacity is large, the reading is requested several times. According to this request of reading, the control part 1c reads the data 18 stored in the storage medium 1a while dividing them into plural blocks 18A, 18B... and afterwards, the first block 18A in this data 18 is transmitted from a communication control part 1e through a communication line 3 to a reception side node 2. Then, a file reception control part 2c of the reception side node 2 writes the first block 18A in the data 18, which is received through a communication control part 2d, through a file write control part 2b to a storage medium 2a and afterwards waits for a transmission end request 19 from the transmission side node 1.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to data communication equipment.

0002

2. Description of the Related Art In a conventional data communication device, as shown in the sequence diagram shown in FIG. Check whether the following is true. If the sending node 1 and the receiving node 2 are data-linked, the sending node 1 issues a file transmission request 12 to the receiving node 2. This file transmission request 12 includes information such as a file name on the transmitting side, a file name on the receiving side, a file format, and a size of the transmitted file. Next, if the receiving node 2 is able to receive the file, it notifies the transmitting node 1 of the start of transmission by sending a file transmission response 13. Then, the sending node 1 transmits all of the file data 14 to the receiving node 2. After all of this file data 14 has been transmitted, the transmitting node 1 requests the receiving node 2 to complete the transmission.
By performing step 5, the end of transmission of all file data 14 is notified. When the receiving node 2 receives all of the file data 14, it notifies the transmitting node 1 of a transmission end response 16. This completes one cycle of data communication between the data-linked transmitting node 1 and receiving node 2.

0003

[Problems to be Solved by the Invention] In the conventional example described above, when the file data 14 can be transmitted by the file transmission response 13, the control procedure (protocol ), when sending a large amount of file data, sending node 1 and receiving node 2 are connected (data link).
This means that the communication line that is currently being used will be monopolized for a long period of time. In particular, in a 1:N network that allows data links between many terminals to one CPU, or an N:N network that allows data links between many terminals, the remaining unlinked This has the disadvantage that many nodes are unable to use the network for a long time.

0004

[Means for Solving the Problems] Accordingly, in the present invention, in a data communication device constituting a 1:N or N:N network, the total transmission file size of file data to be transmitted is transmitted to a sending node. A file transmission control unit is provided that divides the file data into a plurality of blocks and transmits the file data in multiple blocks when the file data is equal to or larger than a predetermined length.

[0005]

[Operation] When the data-linked sending node and receiving node have finished communicating with the file sending request and file sending response, and the receiving node is ready to receive data, the file sending control unit starts sending data. It is determined whether the total transmission file size of the file data to be sent is greater than or equal to a preset length, and if the total transmission file size is less than the prescribed length, the entire file data is transmitted at one time as in the past. On the contrary, if the total transmission file size is greater than or equal to a predetermined length, the file data to be transmitted is divided into a plurality of blocks of a predetermined length and transmitted in multiple blocks.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with the same reference numerals assigned to the same parts as those of the conventional example described above.

FIG. 1 is a block diagram showing a data communication device according to this embodiment, in which a sending node 1 and a receiving node 2 communicate data through a communication line 3 configured as a token-shaped LAN line. It is now linked. This sending node 1 has a storage medium 1a for storing file data 18, and a storage medium 1a for storing file data 18.
A file reading control section 1b for reading data from a file, a file transmission control section 1c for performing a control procedure for transmission, a transmission timing control section 1d for generating a transmission trigger, and a transmission timing control section 1d for controlling a communication line 3. A communication control unit 1e is provided. The control procedure of the file transmission control unit 1c is to determine whether the total transmission file size of the file data 18 to be transmitted detected by the file reading control unit 1b is equal to or larger than a predetermined length;
When the total transmission file size is equal to or larger than a predetermined length, the file data 18 is divided into a plurality of blocks 18A, 18B, . . . and transmitted in multiple batches.

[0008] The receiving node 2 also includes a storage medium 2a for storing file data 18, a file writing control section 2b for writing file data 18 onto the storage medium 2a, and a controller for performing reception control procedures. The communication control unit 2c includes a file reception control unit 2c, and a communication control unit 2e for controlling the communication line 3.

[0009] Here, transmitting side node 1 and receiving side node 2
Data communication between the two will be explained with reference to the sequence diagram shown in FIG.

First, the communication control section 1e of the sending node 1 establishes a connection between the communication control section 2e of the receiving node 2 and the communication line 3.
Check to see if they are physically connected and a data link has been established. Then, when it is confirmed that the data link between the sending node 1 and the receiving node 2 is established, the file reading control unit 1b detects the total transmission file size of the file data 18 stored in the storage medium 1a. Then, this detected value is output to the file transmission control section 1c. Then, the file transmission control section 1c transfers the total transmission file size from the file reading control section 1b to a plurality of files of a predetermined length set in advance to define the exclusive transmission time at one time. 1 in block
8A, 18B..., and calculates the total number of transmissions required to transmit all of the file data 18 and the remaining number of communications, generates a file transmission request 17, and sends this file transmission request 17 to the communication control unit. Communication line 3 from 1e
It is output to the receiving node 2 through. This file transmission request 17 includes, in addition to the sending side file name, receiving side file name, and file format as in the past, the total transmission file size of the file data 18 to be transferred in one transmission,
It includes the total number of transmissions required to transmit all 18 file data and the remaining number of transmissions.

Next, the communication control unit 2e of the receiving node 2
outputs the received file transmission request 17 to the file reception control unit 2c, and if the file reception control unit 2c can receive it, it generates a file transmission response 13 and sends it from the communication control unit 2e to the transmission side node 1 through the communication line 3. Send to.

[0012] Then, the file transmission control section 1c of the sending node 1 that has received this file transmission response 13 requests the file reading control section 1b to read the file data 18 stored in the storage medium 1a. At this time,
If the file data 18 stored in the storage medium 1a has a large capacity and cannot be read with a single read request, the read request is made several times. In response to this read request, the file transmission control unit 1c:
After dividing the file data 18 stored in the storage medium 1a into a plurality of blocks 18A, 18B, . node 2
Send to.

Then, the file reception control section 2c of the receiving side node 2 writes the first block 18A of the file data 18 received through the communication control section 2d to the storage medium 2a through the file writing control section 2b, and then the sending side node Waits for a transmission end request 19 from 1.

After transmitting the first block 18A, the file transmission control section 1c of the transmitting node 1 transmits the second block 18A.
A transmission end request 19 including a delay interval 20 until notification of a file transmission request 19 to block 18B,
When the file reception control section 2c of the reception side node 2 receives this transmission end request 19, the file reception control section 2c transmits a transmission end response 16 to the transmission side node 1. As a result, the first block 18A
One transmission cycle for the data is completed. The delay interval 20 uses a parameter value set by the operator according to the network load such as the throughput and number of nodes on the network.

After the completion of this one transmission cycle, the file transmission control unit 1c of the sending node 1 that has received the transmission end response 16 transmits the file data 18 stored in the storage medium 1a in one transmission. Since this is not possible, the delay interval 20 is output to the transmission timing control section 1d, and the transmission timing control section 1d counts the number of times the empty token passes through the communication control section 1e. and,
When the count number of empty tokens reaches a value corresponding to the delay interval 20 passed from the file transmission control section 1c, the transmission timing control section 1d controls the file transmission control section 1b.
to notify that the sending timing has arrived.

In other words, the file transmission control unit 1c receives the notification that the transmission timing has arrived after the delay interval 20 after receiving the transmission end response 16, and the file transmission control unit 1c receives the notification that the transmission timing has arrived. Part 1c
sends the file transmission request 17 again to the receiving node 2 in the same manner as described above, and the receiving node 2, which received this file transmission request 17, sends the file transmission response 13 to the transmitting node 1.
The sending node 1, which has received this file transmission response 13, sends the second block 18B in the file data 18 to the receiving node 2, and following this transmission, sends a transmission end request 19 to the receiving node 2. The receiving node 2 that received this transmission end request 19 sends a transmission end response 16.
is sent to the sending node 1.

In this way, a plurality of blocks 18A, 18B
All of the file data 18 divided into... are transmitted from the sending node 1 to the receiving node 2 in a plurality of times with a relay interval of 20.

[0018]

As described above, according to the present invention, large-capacity file data is divided into a plurality of blocks, and the plurality of divided blocks are transmitted multiple times. When transmitting files, it is possible to receive file transmission requests from other nodes on the network during the relay interval between divided blocks, thereby increasing the length of the communication line between two data-linked stations. Not only can the inconvenience of exclusive use for a long period of time be eliminated, but also the influence on other nodes can be reduced when a LAN line is used as a communication line. Moreover, since large file data is transmitted in pieces, the error rate of the transmitted data can be reduced, and even if data is retransmitted due to a data error, there is no need to retransmit the entire large file data. You only need to resend the part of the block where the data error occurred, so
There is also the advantage that retransmission work becomes easier.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a sequence diagram of the same embodiment.

FIG. 3 is a sequence diagram of a conventional data communication device.

[Explanation of symbols]

1...Sender node 1a...Storage medium 1b...File reading control section 1c...File transmission control section 2... Receiving side node 3...Communication line 18...File data 18A...1st block 18B...Second block

Claims (1)

[Claims] [Claim 1] In a data communication device constituting a 1:N or N:N network, when the total transmission file size of file data to be transmitted is greater than or equal to a predetermined length, 1. A data communication device comprising a file transmission control unit that divides file data into a plurality of blocks and transmits the divided blocks multiple times.