JPH01292931A - Transmission control device - Google Patents

Abstract

PURPOSE:To attain data transmission with polling by utilizing a transmission requesting signal when the branching service of a high speed digital line is utilized and allocating a data line for one channel on a branching line. CONSTITUTION:A transmission request detecting circuit 18 detects a transmission requesting signal 16, which is sent from a data terminal equipment 11, and a binary signal generating circuit 23 generates a binary signal 22. When the transmission requesting signal 16, which is detected by the transmission requesting signal detecting circuit 18, is turned off, the binary signal 22 from the binary signal generating circuit 23 is selected by a selecting circuit 19 and sent to a transmitting path 25. Then, when the signal 16 is detected to be turned on, transmitting data 17 from the data terminal equipment 11 are selected and sent to the transmitting path 25. Accordingly, when the branching service of the high speed digital line is utilized, the data line for one channel can be allocated on the branching line. Thus, the data transmission can be executed by the polling system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to data transmission by a time division multiplexing device using branching services of high-speed digital lines, and particularly to a transmission control method thereof.

[Conventional technology]

Data communication is performed by connecting two or more data terminal devices via a transmission path. In this case, as shown in FIG. 3, there are three types of lines for connecting these data terminal devices. One is the two-point direct connection method (also called a point-to-point method) shown in FIG.

), this is a system in which specific data terminal devices 11 and 12 are fixedly connected. The second method is the branching method shown in (b) of the figure, which is also called a multipoint method. This is often used in centralized processing systems where a large number of input/output terminal devices are connected to one large central processing device. A large number of data terminal devices 14.15.16 are connected to one line from the data terminal device 13.14 of the center, and the lines between input/output terminal devices and processing devices with a small amount of information are individually connected over time. The efficiency of line usage is increased by multiplexing the lines. 'In this branching method, a procedure called polling selection is normally used to set up logical lines between the data terminal device 13 of the center (master station) and the individual data terminal devices (slave stations). . Polling
Selecting refers to a connection control procedure in which a master station inquires about communication requests from slave stations in turn, and sequentially sets up lines in response to communication requests from its own station. The third one is (C) in the diagram.
As shown in FIG. 2, the exchange device 23.2 is used between a large number of data terminal devices 17 to 22 without setting a parent-child relationship.
4, connections are made as necessary.

This is suitable when the amount of information to be transmitted is relatively small and is evenly distributed among many data terminals. The switching methods in this case include circuit switching and packet switching.

By the way, when the above branching method is applied to a high-speed digital line, an AND circuit is used at the branching point, so
Conventionally, data transmission using a polling procedure has not been possible for uplink signals of high-speed channel information. and,
It required data lines and communication ports for the number of data terminal devices.

[Problem to be solved by the invention]

As described above, this type of conventional system requires data lines and communication ports for each data terminal device, which poses a problem in that the cost of installation equipment and equipment increases.

SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission control device that enables data transmission by polling by allocating one channel of data line on a branch line using a transmission request signal when using a high-speed digital line branch service. It is about providing.

[Means to solve the problem]

A transmission control device for a high-speed digital line according to the present invention is a transmission request signal detection circuit that detects a transmission request signal sent from a data terminal device during data transmission by a time division multiplexing device that uses a branch service of a high-speed digital line. , a binary coded signal generation circuit that generates a binary coded signal that is entirely one of the binary coded codes, and the above-mentioned transmission request signal detection circuit that generates the binary coded signal when the above-mentioned transmission request signal is detected to be off. Selects a binary signal from the circuit and sends it to the transmission path, and when the transmission request signal is detected to be on, selects the transmission data sent from the data terminal device according to this signal and sends it to the transmission path. , and a selection circuit that enables polling transmission with the terminal control device.

Therefore, when the transmission control device for a high-speed digital line according to the present invention is used, the transmission request signal detection circuit detects the transmission request signal sent from the data terminal device, and the binary signal generation circuit generates a binary signal. . When the transmission request signal detected by the transmission request signal detection circuit is off, the selection circuit selects the binary signal from the binary signal generation circuit and sends it to the transmission path, and when the transmission request signal detected by the transmission request signal detection circuit is turned off, At this time, the data to be transmitted from the data terminal device is selected and sent to the transmission path. This enables polling connection with the terminal control device.

〔Example〕

The present invention will be described in detail with reference to Examples below.

FIG. 1 is a block diagram showing a transmission control device for a high-speed digital line according to this embodiment, and FIG. 2 is a block diagram showing a system configuration of a high-speed digital line branching service using this embodiment.

In FIG. 1, a data terminal receiving high-speed digital line branching service is comprised of a data terminal device 31 and a time division multiplexer data communication port 32 connected thereto. The data communication port 32 has a V24/28 ink face 34 defined by CCITT (International Telegraph and Telephone Consultative Committee), and this CCITTV24/28 interface 34 receives a transmission request signal (R3 signal) sent from the data terminal device 31. ) 36 and transmission data 37. Here, V24 indicates an interconnection circuit between a data terminal device and a data line termination device, and V28 indicates an interface whose electrical characteristics of an unbalanced double-current interconnection circuit are regulated by CCITT.

This CCITTV24/28 interface 34 is
3 signal detection circuit 38, to which the R3 signal 36 is sent, and to a 2:1 selection circuit 39, to which the S3 signal 36 is sent.
A D signal 37 is sent out. Furthermore, the R3 signal detection circuit 38
It is connected to a 2:1 selection circuit 39 and sends a selection signal 41 to it. The R8 signal detection circuit 38 is connected to the data terminal device 3
1 is configured to determine whether the R3 signal from 1 is on or off. The 2:1 selection circuit 39 is connected to an all-logic "1" signal generation circuit 43 that generates an all-logic "1" signal 42 indicating that all logics are "1" of the binary code. A "1" signal 42 is sent out. The 2:1 selection circuit 39 selects either the all logic "1" signal 42 or the SD signal 37 according to the selection signal 41 from the R5 signal detection circuit 38,
This is sent out to the transmission line as a sending data signal 45.

Next, the operation of this embodiment will be explained.

The R3 signal 36 from the data terminal equipment 31 is CCITTV
The signal passes through the 24/28 interface 34 and is sent to the R3 signal detection circuit 38. The R3 signal detection circuit 38
3. It is determined whether the signal 36 is on or off. Furthermore, the SD signal 37 from the data terminal device 31 is transmitted to the CCITTV 24/
The signal passes through the 28 interface 34 and is sent to the 2:1 selection circuit 39. When the R3 signal detection circuit 38 detects that the R5 signal 36 is off, the SD signal 37 is invalidated. For this purpose, a selection signal 41, which is a control signal for sending all logic "1" signals 42 to the transmission path, is sent to the 2=1 selection circuit 39. When the 2:1 selection circuit 39 receives this selection signal 41, it selects the all-logic "1" signal 42 from the all-logic "1" signal generation circuit 43, and sends this out to the transmission path as a sending data signal 45. . On the other hand, when the R3 signal detection circuit 38 detects that the R3 signal 36 is turned on, the SD signal 37
becomes valid. The R3 signal detection circuit 38 sends a selection signal 41 indicating this to the 2=1 selection circuit 39, and the 2:1 selection circuit 39 selects the SD signal 37 according to this selection signal 41 and uses it as the sending data signal 45. It is sent to the transmission path as

FIG. 2 shows a system using a high-speed digital line using this embodiment.

Data communication ports 51 and 52 of this embodiment shown in FIG.
The two join at a branch point 53 and are controlled via a transmission path 54 by a computer 55 as a terminal control device. This computer 55 is also connected to the transmission line 54 via a data communication port 56 having the same functions as those in this embodiment.

Data terminal devices 57 and 58 are connected to the data communication ports 51 and 52, respectively.

The operation of this system is as follows.

First, the computer 55 receives R3 from the data terminal device.
When the signal 60 is on, the R3 signal 61 of the data terminal device 58 is on, and control is performed so that these signals do not turn on at the same time. Here, R3 from the data terminal device 57
When the signal 60 is detected to be on at the data communication port 51, the output data signal 63 sent from the data communication port 51 to the transmission path 54 becomes the SD signal 64 from the data terminal device 67, as described above. On the other hand, in this case, since the R3 signal 61 from the data terminal device 58 is controlled to be on, the SD signal 65 from the data terminal device 58 is disabled, and the data communication port 52
From there, a full logic "1" signal 66 is sent out to the transmission path 54 as a sending data signal 67. Considering that an AND circuit is configured at the branch point 53, the upstream signal 67 at the branch point 53 at this time is as follows: Upstream signal 67 = (transmission data signal 63) x (transmission data signal 67) = (data terminal device 57's SD signal 64)×(all logic "1" signal 66)=(SD signal 6 of data terminal device 57) Therefore, data transmission by polling becomes possible.

〔Effect of the invention〕

As described above, the transmission control device for a high-speed digital line of the present invention includes an R3 signal detection circuit that detects whether the R3 signal sent from the data terminal device is turned on or off, and a signal that is all binary coded. When the R3 signal detection circuit detects that the R3 signal is off, it selects the binary signal from the binary signal generation circuit and sends it to the transmission path, and when it detects that the R3 signal is on, it outputs the above data. By providing a selection circuit that selects the SD double signal from the terminal device and sends it to the transmission line, it is possible to allocate one channel worth of data line on the branch line when using high-speed digital line branch service. This has the effect of enabling data transmission.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a line configuration for connecting data terminal devices; FIG. 31...Data terminal equipment, 32...Time division multiplexer data communication boat,
34...CCITT, V24/28, interface, 38...R3 signal detection circuit, 39...Selection circuit, 43...All logic "1" signal generation circuit.

Claims (1)

[Claims] In data transmission by a time division multiplexing device that utilizes a high-speed digital line branching service, a transmission request signal detection circuit that detects a transmission request signal sent from a data terminal device, and a transmission request signal detection circuit that is entirely binary encoded. a binary coded signal generation circuit that generates a binary coded signal that is either one of the codes; and a binary coded signal generation circuit that generates a binary coded signal from the binary coded signal generation circuit when the transmission request signal is detected to be off by the transmission request signal detection circuit. When the transmission request signal is detected to be on, the terminal control device selects the transmission data sent from the data terminal device under the control of this signal and sends it out to the transmission path. 1. A transmission control device for a high-speed digital line, comprising a selection circuit that enables a polling connection between the lines.