JPH01297749A - Host computer - Google Patents

Abstract

PURPOSE:To evade the deletion of untransmitted data by monitoring the presence/absence of data in a transmission data buffer by a received line cutoff request. CONSTITUTION:A host computer 1 is connected to a terminal equipment 4 via a switched line 2, and the computer 1 is provided with a transmission buffer 15 which stores data processed by an application program 11 transiently, an asynchronous transmission means 12 which performs the automatic transmission of the data in the buffer 15 to the terminal equipment 4, an input/output means 14, an outgoing means 18, a monitoring means 17 which monitors the presence/ absence of the data in the buffer 15, and a line cutoff recovery means 16. When the line cutoff request is issued from the terminal equipment, the recovery means 16 continues and completes a cutoff processing when it is judged that no untransmitted data exists in the buffer 15 by the monitoring means 17, and when it is decided that the data exists in the buffer, the transmission means 12 that is an automatic transmission means is re-started up, and the transmission of the data in the buffer is executed, then, the cutoff processing is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is utilized as means for recovering from a disconnection of a public communication line. In particular, it relates to reconnection means after receiving a line disconnection code.

〔overview〕

The present invention avoids discarding incompletely transmitted data by restarting the disconnection process after the data on the transmit buffer has been transmitted, in a line disconnection recovery means of a host computer that has a transmit buffer and performs asynchronous transmission. It has been made possible to do so.

[Conventional technology]

In the conventional example, when a line disconnection code (DLB, EOT) is received, the public communication line is immediately disconnected, and subsequent reconnection to the public line is left to the application program.

[Problem that the invention seeks to solve]

In such a conventional example, the public communication line is immediately disconnected when a line disconnection code is received, so a host computer that has an asynchronous transmission means that uses a transmission buffer for application data transmission processing and transmission processing with a terminal If there is transmission data of an application program on Hanwha, the transmission data is discarded, resulting in a mismatch between the transmission data of the application program and the data received by the terminal.

SUMMARY OF THE INVENTION The present invention aims to eliminate such drawbacks, and provides a host computer that can prevent transmission data from being discarded.

[Failure to solve the problem]

The present invention is connected to a terminal device via a public communication line,
In a host computer that is equipped with a transmission buffer that temporarily stores data processed by an application program and automatic transmission means that automatically transmits the data on this transmission buffer to the terminal device, the presence or absence of data on the transmission buffer is monitored. a monitoring means for starting the disconnection process of the public communication line in response to a line disconnection request received from the terminal device, and receiving a monitoring result of the monitoring means;
When the monitoring result indicates that there is no data on the sending buffer, this disconnection process is terminated, and when the monitoring result shows that there is data on the sending buffer, the above The system is characterized by comprising a line disconnection recovery unit that restarts the automatic transmission unit to transmit the data on the transmission buffer, and executes a disconnection process of the public communication line after the transmission of the data is completed. do.

[Effect]

Monitors the presence or absence of data on the sending device used for asynchronous transmission, and immediately disconnects the public communication line using the line disconnection code received from the terminal if there is no data to send for the disconnection program on the sending device. conduct,
If there is data, connect to the terminal again, transmit the transmission data on the transmission buffer, and then perform disconnection processing. This prevents the transmission data from being discarded even if the public communication line is disconnected, and avoids discrepancies between the transmission data and the data received at the terminal.

〔Example〕

Hereinafter, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment.

As shown in FIG. 1, this embodiment is comprised of a host computer 1 and a terminal 4 connected to the host computer 1 via a telephone switching network 3 via a public communication line 2. Here, the host computer 1 includes an application program section 110 that stores an application program 11, and an asynchronous transmission means 12 that stores and retrieves transmission data into and from the transmission buffer 15, and performs data transmission processing from the application program 11. , a control means 13 that performs fault detection and recovery using a data transmission control procedure when an abnormality is detected in transmission, an input/output means 14 that converts data into serial and parallel data and transmits and receives a signal to and from the terminal 4, and transmits data to be transmitted. A transmission buffer 15 for storing data, a line disconnection recovery means 16 for performing disconnection processing and disconnection recovery processing for the public communication line 2 based on a line disconnection code received from a terminal, and a monitoring means for monitoring and notifying the presence or absence of data on the transmission buffer 15. 17, and a calling means 18 that automatically calls the terminal 4 at a predetermined telephone number. The feature of the present invention is that, in FIG. 1, line disconnection recovery means 16 and monitoring means 17 are provided.

That is, this embodiment includes a transmission buffer 15 that is connected to the terminal device 4 via the public communication line 2 and temporarily stores data processed by the application program 11, and a transmission buffer 15 that sends the data on this transmission buffer 15 to the terminal device 4. The asynchronous transmission means 12, the input/output means 14, and the transmission means 18, which are automatic transmission means for automatic transmission, the monitoring means 17 that monitors the presence or absence of data on the transmission buffer 15, and the starts the disconnection process of the public communication line 2, receives the monitoring result of the monitoring means 17, and when the monitoring result shows that there is no data on the transmitter sofa 15, continues and ends the disconnection process, and
When the monitoring result indicates that there is data on the transmitter sofa 15, the automatic transmission means is restarted to transmit the data on the transmitter sofa 15, and after the transmission of this data is completed, the public communication line 2 and line disconnection recovery means 16 for executing disconnection processing.

Next, the operation of this embodiment after the host computer 1 and the terminal 4 are able to communicate via the telephone switching network 3 after the automatic dialing of the telephone number will be described. Asynchronous transmission means 1 according to a transmission request from application program 11
2 receives the data, stores this data in the transmission buffer 15, then takes out this data and passes it to the control means 13. After converting this data into a transmission frame format, the control means 13 transmits the transmission frame and transmission control code to the input/output means 14 according to a predetermined transmission control procedure.
give it to The input/output means 14 converts this from bit parallel to bit serial and sends it to the public communication line 2.

This transmission frame and transmission control code reach the terminal 4 via the telephone switching network 3. Data is transmitted in this way, and when the work is finished or an abnormality occurs in the terminal 4, the terminal 4 generally sends a line disconnection code (DLIE, [EOT
) is sent and the disconnection process is performed.

This cutting processing operation will be explained based on FIG. 2.

This line disconnection code is passed to the control means 13 through the input/output means 14 (step Sl). Here, upon receiving the line disconnection code, the control means 13 passes control to the line disconnection recovery means 16 (step S2). The line disconnection recovery means 16 that has been given control receives the notification from the monitoring means 17, and if there is no incomplete transmission data of the application program 11 (step S3), it immediately disconnects the public communication line 2 as before (step S4). ). If there is incomplete transmission data (step S3), line disconnection recovery means 1
6 passes control to the transmitting means 18, and the transmitting means 18 transmits the control to the terminal 4.
makes an automatic call to a predetermined telephone number, passes control to the line disconnection recovery means 16, and the line disconnection means 16 that has been given control reconnects the terminal 4 and becomes communicable. Control is passed to the control means 13, and the control means 13 receives the incomplete transmission data held in the transmission buffer 15 from the asynchronous transmission means 12,
The information is transmitted to the terminal 4 according to the transmission control procedure (step S5). After the incomplete transmission data has been sent, control is transferred from the control means 13 to the line disconnection recovery means 16, and the public communication line 2 is disconnected.

As described above, according to this embodiment, when a line disconnection code is received, the presence or absence of uncompleted transmission data is monitored, and if there is uncompleted transmission data, the terminal 4 is connected again and the uncompleted transmission data is transmitted. After that, the public communication line 2 is disconnected as in the conventional manner.

〔Effect of the invention〕

As explained above, even if a line disconnection code is received, if there is incomplete transmission data, the present invention connects to the terminal again and transmits the incomplete transmission data, so that the application program can recover the incomplete transmission data. It has the effect of reducing the load.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing the configuration of an embodiment of the present invention. FIG. 2 is a flowchart showing the operation of the embodiment of the present invention. 1... host computer, 2... public communication line,
3... Telephone switching network, 4... Terminal, 11... Application program, 12... Asynchronous transmission means, 1
3... Control means, 14... Input/output means, 1
5... Transmission buffer, 16... Line disconnection recovery means, 1
7... Monitoring means, 18... Transmitting means, 110...
Abricane Yon Program Club.

Claims (1)

[Claims] 1. A transmission buffer that is connected to a terminal device via a public communication line and temporarily stores data processed by an application program, and automatic transmission that automatically transmits the data on this transmission buffer to the terminal device. a monitoring means (17) for monitoring the presence or absence of data on the transmission buffer; and a host computer comprising: a monitoring means (17) for monitoring the presence or absence of data on the transmission buffer; Upon receiving the monitoring result of the monitoring means, if the monitoring result indicates that there is no data on the sending buffer, the disconnection process is continued and terminated, and if the monitoring result indicates that there is data on the sending buffer. line disconnection recovery means (16) that restarts the automatic transmission means to execute the transmission of the data on the transmission buffer, and after the transmission of this data is completed, executes the disconnection process of the public communication line; A host computer comprising: