JPS61140256A - Return data transmission system - Google Patents

Abstract

PURPOSE:To transmit a return data from a user terminal device to a center while a pattern data is transmitted on its way by adding a code representing the presence of a return data from the user terminal device to an acknowledgement signal and transmitting the result. CONSTITUTION:The pattern data is fetched via a MODEM17, and when a CPU12 uses a program stored in a ROM13 to receive one data block, it is stored in a memory 15 for 9 scopes' share, and when a commanded return data from a key pad 20 exists, an ETB code is added to the ACK signal and the result is transmitted, and then the return data is transmitted. When no return data exists, an ETX code is added to the ACK and the result is transmitted and the system is in the standby state. When no ACK returns, a CPU5 of the center 1 retransmits the data of the preceding one data block and when the ACK is returned and the ETB code is added, the returned data is received, the further transmission of scope data is stopped or a scope data in response to the content of the return data is transmitted by the processing of the CPU5.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention serially transmits data for multiple screens at once from a center to a user terminal, and receives unit blocks of data from the user terminal. The purpose of this invention is to improve the return data transmission system of a small-scale Videotex system used in companies, which is a half-duplex transmission system that sends an acknowledgment signal to the center every time a request is made.

In a normal Videotex system, what can be displayed on one screen is divided into several hundred parts in a small-scale Videotex system and sent serially from the center. The information is stored in memory and displayed one after another starting from the first page, and when return data is required, a human instructs the transmission of the return data.

For example, when a user terminal requests to display a menu, the menu has 72 items, 8 items can be displayed on 1 screen (1 page), and it is divided into 9 pages, and 1 page is divided into 3 blocks. Assuming that the terminal has 9 pages of memory, the center first sends one block of data to the user terminal, and when the user terminal receives this, it sends an acknowledgment signal (hereinafter referred to as ACK). When the center receives this, it repeats the above operation to transmit the next block of data, and continues to transmit nine pages.

When the user terminal receives one screen's worth of menu data, it displays it on the display, and when the user wants to see the next screen's menu, they can press the next page key to see the next screen. I can do it.

For example, if there is a menu that you want to see details on the second page, if a human instructs this, the data from the third page onwards will be unnecessary, but the data for one page will be displayed. It takes about 1 second to send the data, so at this time 9 pages of screen data are being sent, and the return data is being sent.
If it is sent after a page's worth of screen data has been sent, unnecessary screen data will be sent, but return data is sent even during the screen data transmission, so unnecessary screen data is not sent as much as possible, and transmission efficiency is improved. Good things are desirable.

[Conventional technology]

In the conventional return data transmission method, while the center is processing screen data transmission, the user terminal only returns ACK, and when return data is generated, the user terminal requests the center to send data after receiving the screen data. After receiving an OK response or receiving an inquiry from the center about the presence or absence of return data after sending the screen data, the sending right was secured and the return data was sent.

[Problem that the invention seeks to solve]

Therefore, in the above method, since return data cannot be sent until the transmission of screen data from the center is completed, there is a problem in that unnecessary screen data may be sent, reducing transmission efficiency.

[Means for solving problems]

The above-mentioned problem is solved by the return data transmission method of the present invention, in which a code indicating whether there is return data from the user terminal is added to the confirmation response signal before transmission.

[Effect]

According to the present invention, if the user terminal has return data, it adds a code indicating this to 80K and then sends the return data, so the center can determine whether there is return data while transmitting the screen data. If there is return data, the center interrupts the transmission of the next screen data and receives the return data, so that unnecessary screen data is less likely to be sent and transmission efficiency can be improved.

〔Example〕

FIG. 1 is a flowchart of the main parts of the program of the center and user terminal according to the embodiment of the present invention, and (A) shows the program of the center (B).
indicates a user terminal, and FIG. 2 is a block diagram of the main parts of an example of a small-scale videotex system.

In Figure 2, 1 is the center, 2 is the telephone line, 3 is the user terminal,
4 is a telephone, 5.12 is a CPU, 6 is an interface section with data and human power, 7 is a disk memory, 13 is a ROM,
8.14 is RAM, 9 is communication control unit, 1.0.17 is modem, 11 is network control unit, 15 is memory for 9 screens, 16
18 is a display section, 18 is a line control unit, 19 is an interface section, and 20 is a keypad.

The connection between the center 1 and the user terminal 3 is performed by a dial signal from the telephone 4, and this signal is sent to the telephone line 2 via the line control unit 18 of the user terminal 3, and is sent to the telephone exchange (not shown). ), the center 1 is selected, a paging signal is sent to the network control unit 11 and connection is established, and the user terminal 3
On the side, the telephone line 2 is controlled by the operation of the line control unit 18.
is connected to the modem 17 side to form a line.

When a menu transmission request is made from the user terminal 3 using, for example, the key bat 20, this signal is sent to the interface unit 19. Modem 17, line control unit 18. The program shown in FIG. 1(A) is sent to the center 1 via the telephone line 2, is taken in via the network control unit 11, modem 102 and communication control unit 9 within the center 1, and is stored in the ROM 7 and is stored in the CPU 5. In this way, one data block of screen data is transmitted.

This data is stored in the communication control unit 9. Modem 10. [Control unit 11
．． Telephone line 2. Line control unit 9 of user terminal 3.
is taken in via modem 17, and CPU 12 reads ROM1.
If one data block is received by the program shown in FIG. 1(B) stored in the memory 15 stored in the
If there is return data instructed by the key bat 20, send an ACK with an ETB code added to it, then send the return data, and if there is no return data, send an ACK.
The ETX code is added to the file, the ETX code is added, and the data is sent to a waiting state.

The CPU 5 of the center 1 receives this using the program shown in FIG. If the return data is returned and an ETB code is attached, the return data is received, and processing such as stopping further transmission of screen data and transmitting screen data according to the contents of the return data is performed.

If an ETX code is attached, the above operation is repeated until one page of screen data has been transmitted, and the transmission continues until nine pages of screen data have been transmitted.

Of course, during this time, an ACK signal is returned every time data block is transmitted, but if an ETB code is added to this,
Center 1 performs the same processing as when the ETB is added.

In this way, the return data can be sent from the user terminal 3 to the center 1 even while the screen data is being sent, making it possible to stop sending unnecessary screen data and improving transmission efficiency. I can do it.

〔Effect of the invention〕

As explained in detail above, according to the present invention, return data can be sent from the user terminal to the center even while screen data is being sent, making it possible to stop sending unnecessary screen data. This has the effect of improving transmission efficiency.

[Brief explanation of the drawing]

FIG. 1 is a flowchart of a program for the main parts of a center and user terminals according to an embodiment of the present invention, and FIG. 2 is a block diagram of the main parts of an example of a small-scale video technology system. In the figure, l is the center, 2 is the telephone line, 3 is the user terminal, 4 is the telephone, and 5.12 is the CPU. 6.19 is an interface section, 7 is a disk memory, and 8.14 is a RAM. 9 is a communication control unit, 10.17 is a modem, 11 is a network control unit, and 13 is a ROM. 15 is a memory for nine screens, 16 is a display section, 18 is a line control unit, and 20 is a keypad. (Eight)

Claims (1)

[Claims] A half-duplex transmission method in which data for multiple screens is serially transmitted from a center to a user terminal at once, and an acknowledgment signal is sent to the center each time a unit block of data is received from the user terminal. 1. A return data transmission method in a Videotex system, characterized in that a code indicating the presence or absence of return data from a user terminal is added to the acknowledgment signal before transmission.