JPS62100854A - Communication system between host and terminal - Google Patents

Abstract

PURPOSE:To omit the need to change the system generation when the real terminal constitution is changed by setting previously a virtual terminal having the 1:1 correspondence secured between a host and an application program and connecting the virtual terminal to a real terminal with the designation of the application program sent from the real terminal. CONSTITUTION:The dynamic correspondence is secured between virtual terminals 31-34 and real terminals 41-49 via a switch means 35. When the real terminal 41 delivers a telegram indicating an application program AP2, a relay processor 30 checks the using condition of the virtual terminal corresponding to the program AP2. If said virtual terminal is idle, it is connected to a real terminal. Thus a communication path is secured and the real terminal performs the processing by means of the program AP2.

Description

Detailed Description of the Invention (Field of Application in the Music Industry) The present invention relates to a communication system between a host and a terminal. The present invention relates to a method of communication with a terminal device (hereinafter referred to as an actual terminal).

(Prior art) When constructing a network for communication between a host and multiple real terminals, when the distance between each node is long and the number of real terminals and therefore the number of lines is large,
Generally, a relay processing device is introduced. In other words, the host and the relay processing device are connected via a high-speed line and communication control is performed at a speed that matches the processing speed of the host, and the relay processing device and the actual terminal are connected via a low-speed line to perform communication control at a speed that matches the processing speed of the actual terminal. We are trying to accommodate.

On the other hand, when adding functions or modifying software, it is well known from experience that the larger the base software, the more difficult the task is and the more likely mistakes are to be made. Therefore, in order to cope with the diversification of real terminals accompanying the expansion of computer applications, the part that must be aware of the attributes of real terminals is communication control processing on the host side, such as a front-end processor. It is desirable to set the virtual terminal so that it is handled by a dedicated section and the operating system can specify the address of the terminal to communicate with and send/receive data without being aware of the attributes of the real terminal.

This type of conventional communication method between a host and a terminal is
The setting of a virtual terminal with one-to-one correspondence and the connection between the virtual terminal and the application program are performed on the host during system generation (SG), and communication between the host and the real terminal is performed via this virtual terminal. I'm trying to execute it.

(Problems to be Solved by the Invention) In such a conventional method, it is necessary to configure as many virtual terminals as there are real terminals, which increases the configuration time and reconfiguration time when the host goes down, and the number of virtual terminals increases. The number of buffers and tables created for each virtual terminal increases, which increases the resources required on the host.Also, since the connection between virtual terminals and real terminals is fixed at SG time, when adding real terminals, etc. There are many problems in that if there is a change in the configuration of the SG, it is necessary to redo the SG, and it is not possible to take various operational forms of the real terminal by dynamically linking the real terminal and the virtual terminal.

(Means for Solving the Problems) The method of the present invention is executed by a host and a host in a host-terminal communication method in which communication is performed between a host and a plurality of real terminals via a relay processing device. ! A virtual terminal with one-to-one correspondence with an application program is set in advance in the relay processing device, and the real terminal waits for a request message specifying the application program and a permission message from the relay processing device in response to this request message, and then enters the actual terminal name. When the relay processing device receives the request message, it replies with the above-mentioned permission message depending on the usage status of the corresponding virtual terminal, and sends the above-mentioned communication message to the corresponding host via the corresponding virtual terminal. Also, the response message from the host to the communication message is transferred to the real terminal via the corresponding virtual terminal, and when the host receives the communication message, it processes it with the corresponding application program and then attaches the real terminal name. This feature is characterized in that the response message sent is sent as follows.

(Example) Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. Referring to FIG. 1, this embodiment includes a host 10 that executes an application program API and Ar2, and an application program API and Ar1. Executing host 20 and nine real terminals 41, 42, 43, 44, 4
5, 46, 47, 48 and 49, and these real terminals 4
1 to 49 and hosts) 10 and 20 to perform relay processing.

The relay processing device 30 includes application programs API and Ar2 executed on the host 10, and an application program AP executed on the host 20.
Four virtual terminals 31, 32, 33 and 3 correspond to a total of four application programs, I and Ar1.
4 is set to 80 o'clock, and these temporary terminals are switched to switching means 3.
5, it is dynamically associated with nine real terminals 41 to 49. The O marks in the hosts 10 and 20 and the relay processing device 30 represent images of virtual terminals or real terminals in the respective devices.

Next, referring to FIG. 2 which shows the details of the relay processing device 30 together with the actual terminal and the message, in order to avoid complication of the drawing, FIG.
I and AP2 are shown assuming an online computer system in which four real terminals A, B, C, and D are used.
Two tables 51 and 52 that correspond one-to-one to PI and AP2, and four tables 53, 54, 55, and 56 that correspond one-to-one to real terminals A, B, C, and D are provided.

In the tables 51 and 52, information for host management, such as data indicating whether the table is shared by a plurality of real terminals or dedicated to one host, is written at the time of 8G. Also, tables 53, 54,
55 and 56, terminal management information is real terminal A, B, C
The switching means 35 connects the tables 53 to 56 to either of the tables 51 and 52 based on the written information.

Tables 53, 54, 55 and 56 are fixedly associated with real terminals A, B, C and D, respectively. on the other hand,
Tables 51 and 52 can be associated with either application program API or AP2 by writing either table 51 or 52 into a table (not shown) corresponding to the application program on the host side at 80 o'clock. can.

Now, the operation of this embodiment will be explained by taking communication between the real terminal A and the application program AP2 as an example.

First, the real terminal A transmits the first message r$cON, AP2J. This first message requests communication with the application program AP2, and is sent to the relay processing unit [3].
The control unit 0 (not shown) checks the usage status of the table 52 corresponding to the application program AP2, and if it is free, returns a permission message to the actual terminal person, and the switching means 35 switches between the table 53 and the table 52. control to connect.

In this way, the communication path between the real terminal A and the application program AP2 has been set, so
When real terminal A receives the above-mentioned permission message, it sends the second message “A.
, data” is sent. This second message is communication data attached with the real terminal name of the sender, and is delivered to the application thin program AP2 for processing through the communication bus set based on the first message.

At this time, the application program AP on the host
2 performs the process based on the actual terminal name in the message, and when this process is completed, the host sends the third message "A, response",
The second message "A, data" is transmitted to the receiving virtual terminal and delivered to the actual terminal via the above-mentioned communication path.

This m3 message is notifying the processing result of the second message by the application program AP2, and when the actual terminal A receives the third message, it sends the fourth message [$DISJ or the second message] depending on the response content. “A.

data”.

The second message ``A, data J was retransmitted because the processing on the host side was not carried out normally, but the message ``$D■SJ'' in whistle 4 indicates the end of communication. When the relay processing device 30 receives the fourth message, it controls the switching means 35 to disconnect the table 53 and the table 52, thereby terminating the communication.

In addition, in the embodiment described above, in order to simplify the explanation,
Although this is a relatively small-scale system with only one relay processing device, it is also possible to easily implement an embodiment having a plurality of relay processing devices, each of which relays processing a large number of real terminals to a host.

(Effects of the Invention) According to the present invention, as explained above, the number of virtual terminals set at 80:00 is the same as the total number of application agent programs executed on each host, and this number is generally the same as the number of real terminals. Since the number of virtual terminals is considerably smaller than the number of virtual terminals, the time required to set up a virtual terminal and the time for resetting when a host is down can be shortened, and the resources required on the host to set up a virtual terminal can also be reduced.

In addition, since the connection between a virtual terminal and a real terminal is done dynamically using a message from the real terminal, there is no need to redo the SG even if the configuration of the real terminal changes, and one virtual terminal can be connected to multiple devices. Conversely, one real terminal can be linked to a plurality of virtual terminals, and various operating forms of the real terminal can be dynamically adopted.

In addition, since the host does not need to be aware of the communication route through which the message from the real terminal came, in a system with multiple relay processing devices, if a relay processing device fails, it will be sent to a relay processing device other than the real terminal. Connect with switched line. In addition, in the event of a line failure between the host and the relay processing device, the detour processing can be performed simply by connecting the relay processing device and another relay processing device using a switched line.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, and FIG. 2 shows a detailed diagram of this embodiment. 10.20...Host computer (host)
, 30... Relay processing device, 31, 32, 33,
34... Virtual terminal, 35... Switching means, 41, 42, 43° 44.45, 46, 47.4B,
49, A, B, C, D... terminal device (actual terminal), 51, 52, 53, 54°55, 56...
·table. Agent Patent Attorney Uchihara i''tyt Figure 2

Claims (1)

[Scope of Claims] In a host-terminal communication method in which communication is performed between a host computer and a plurality of terminal devices via a relay processing device, there is provided a system that corresponds one-to-one to an application program executed on the host computer. means for setting a virtual terminal in the relay processing device; and waiting for a request message placed in the terminal device specifying the application program and a permission message from the relay processing device in response to the request message, and then setting the name and data of the terminal device. means for transmitting a communication message including; means disposed in the relay processing device for replying the permission message depending on the usage state of the virtual terminal when receiving the request message; and means for transmitting the communication message via the virtual terminal. means for transmitting a response message from the host computer to the corresponding host computer via the virtual terminal; and a means disposed in the host computer for receiving the communication message. A host-terminal communication system comprising: means for transmitting the response message to which the name of the terminal device is attached after processing by the application program.