JPS61274549A - Transmission and reception controller - Google Patents

Abstract

PURPOSE:To omit the exchange of programs caused by a switching operation and to cope flexibly with different communication systems, by controlling with switching the different data transmission/reception control systems with a command through a control processor. CONSTITUTION:When the presence of a control message is informed by a circuit open command, the end of transmission is informed to an application program 4 after an answer of the station at the remote side is received to the transmission data while a sending command given from the program 4 is processed. Then the end of reception is informed to the program 4 after an answer to be sent to the station at the remote side is transmitted to the reception data while a receiving command sent from the program 4 is processed. While the transmission data received from the program 4 is delivered to a communication control processor 2 in a transmission mode when no control message head exists. Then the end of transmission is informed to the program 4 after the information of the end of transmission. In the reception mode the reception data given from the processor 2 is delivered to the program 4 and the end of reception is informed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to data transmission/reception control means for a personal computer connected to a local area network.

Among the interconnection functions of computers and terminals, the application layer executes application protocols to enable communication between users, and the transport layer absorbs network differences and transfers data between sessions. is transmitted transparently,
Furthermore, the presentation layer implements functions related to information display formats such as data encoding and formatting.

〔overview〕

The present invention provides a transmission/reception control device used in a local area network that supports different data transmission/reception control methods depending on the presence or absence of application dependence on the presentation layer. This makes it possible to efficiently switch between different data transmission/reception control methods by making selections based on the dependence of layer applications.

[Conventional technology]

Conventional data transmission and reception between personal computers connected to a local area network was performed as follows.

(11) The first type of data transmission and reception between personal computers, which must support a large number of applications, is the transmission and reception of only data that depends on the hardware.

(2) The format of the communication message and the presentation including the coding rules can be determined between the personal computer and the host computer.The second data transmission and reception between the personal computer and the host computer is independent of hardware and can be performed by adding a control message header. The reliability of transmitted and received data is improved by notifying detailed information such as specifying the destination of transmitted data or returning acknowledgments, negative responses, retransmission requests, and interruption requests in response to received data in control message headers.

[Problem that the invention seeks to solve]

Data transmission and reception by personal computers connected to such local area networks has the following drawbacks.

(1) Switching between two types of data transmission and reception requires program replacement or system restart, which is inefficient.

(2) Data transmission/reception with control message header added (i
It is difficult to implement this method on all personal computers due to obstacles such as unification of control messages and transmission formats.

(3) If only data without a control message header is sent and received with the host computer, the reliability of the sent and received data will deteriorate.

The present invention aims to eliminate such drawbacks and to provide a transmission/reception control device that can efficiently execute different data transmission/reception methods.

[Means for solving problems]

The present invention is a transmission/reception control device provided in a node included in a local area network, which is inserted between an application layer and a transport layer of the node as a means for solving the above-mentioned problems. The present invention is characterized by comprising a control means for selecting either execution or non-execution of adding a control message to the beginning of the data sent from the node, depending on whether or not the application of the presentation layer is dependent on the application.

That is, the present invention is characterized in that it is possible to switch between a control message with a header and a control message without a header by a communication command.

[For production]

Data transmission and reception between personal computers connected to a local area network is executed depending on the hardware, and data transmission and reception between the personal computer and the host computer is performed by adding a control message to the beginning of the data to ensure the reliability of the transmitted and received data. Retained. The control means added according to the invention enables or disables the addition of a control message to the head of the transmitted data, depending on whether or not it is possible to predefine an application-dependent presentation layer for the presentation, including the communication message format and coding rules. Execution is selected to efficiently switch between different data transmission and reception methods.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS A device according to an embodiment of the present invention will be described below with reference to the drawings.

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

FIG. This embodiment device includes a transporter 1 that is a device that executes data transmission and reception, a communication control processor 2 that is a processor that controls the transporter 1, an application program 4, and a communication protocol that is a processor that manages data transmission and reception control. and a control processor 3.

A feature of the present invention is that it includes a communication protocol control processor 3, and that this processor executes data transmission and reception control based on a line open command from an application program 4.

First, when the presence of a control message header is notified by the line open command, as shown in Figure 2, when processing the send command from the application program 4, the application The program 4 is notified of the end of transmission, and when processing a receive command from the application program 4, the application program 4 is notified of the end of reception after transmitting a response to the received data to the partner station. That is, as shown in FIG. 4, at the time of transmission, a control message header is added to the beginning of the transmission data received from the application program 4, and at the time of reception, the data received from the communication control processor 2 is transmitted. The control message header at the beginning of the received data is deleted, and only the data part is passed to the application program 4.

Furthermore, the communication protocol control processor 2 manages the control of communication protocols with the host computer, assembling control messages, and notifying the application program 4 of fftlJj wholesale messages from the other station.

On the other hand, in the case where there is no control message header, as shown in FIGS. 3 and 4, the transmission data received from the application program 4 is passed as is to the communication control processor 2 at the time of transmission, and If there is a transmission end notification from 2, the application program 4
is notified that the transmission has ended. At the time of reception, the received data received from the communication control program 2 is passed as is to the application program 4, and a notification of the end of reception is issued.

〔Effect of the invention〕

As explained above, the present invention enables a communication protocol control processor to switch and control different data transmission/reception control methods using commands, thereby eliminating the need for program exchange or system restart due to switching. This has the effect of being able to respond flexibly.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing the configuration of an apparatus according to an embodiment of the present invention. FIG. 2 is a sea fence diagram showing the flow of commands when opening with a control message header is performed. FIG. 3 is a sea fence diagram showing the flow of commands when opening is performed without a control message header. FIG. 4 is a sea fence diagram showing the flow of transmitted and received data. ■...Transporter, 2...Communication control processor, 3...Communication protocol control processor, 4...Application program.

Claims (1)

[Claims] (1) In a transmission/reception control device provided in a node included in a local area network, the device is inserted between the application layer and the transport layer of the node, and depending on whether or not the application of the presentation layer of the node depends, A transmission/reception control device characterized by comprising a control means for selecting execution or non-execution of adding a control message to the beginning of data sent from the node.