JPS62154158A - Communication controller for data transmission system - Google Patents

Abstract

PURPOSE:To attain the transmission of data at a high speed and with high efficiency by separating a command line from a data bus in order to perform the transfer of both data to be processed and command data in parallel with each other. CONSTITUTION:Terminal equipments 12a-12c are connected to each other via command lines 13a-13c, a data bus 14 and star coupler 11. A terminal control instruction and its answer are transferred between the equipments 12a-12c and the coupler 11 via the lines 13a-13c respectively. While a large amount of data are transferred among those equipments 12a-12c via the bus 14. Here these terminal control instructions and data are transferred in parallel with each other. Then the application timing of the bus 14 is controlled by the coupler 11. As a result, the using efficiency of the bus 14 is improved together with improvement of the working efficiency of those terminal equipments.

Description

[Detailed Description of the Invention] A communication control device in a t3Aia data transmission system originating from the field of industrial application, in particular, a command line and a data node are separated from each other, making it possible to send and receive command data during overall data transfer. This is related to communication control equipment.

2. Description of the Related Art A conventional data transmission system is one shown in FIG. 4, for example. It consists of a single bus 1, a plurality of terminal devices 3 connected to this single bus 1, a transceiver 2 providing a coupling between the single bus 1 and each terminal device 3, and a single bus 4. It consists of a repeater 4 that is used when there is a need for extended periods of time. In such a data transmission system, when the terminal device 3 attempts to transfer data,
First, it is detected whether the single bus 1 is being used by another terminal device 3, and if the single bus 1 is free, a transmission frame is sent. When a transmission is made from one terminal device 3, all the terminal devices 3 connected to a single bus 1 can sense the transmitted frame, and each terminal device 3 passes through the single bus 1. A transmission path is established between the terminal device 3 and the originating terminal device 3 after checking whether the destination address of the transmission frame is addressed to the self. In addition, if transmission frames are sent from secondary or higher terminal devices 3 at the same time (so-called collision), the transceiver 2 of the terminal device 3 that sent the transmission frames senses the collision of the transmission frames and temporarily stops the transmission operation. Abort.

Then, after a predetermined period of time has elapsed, the transmission frame is sent to the single bus 1 again, and it is checked whether the single bus 1 is free. In this case, normally the time until the second transmission frame is sent is set differently between the terminal devices 30, so that a collision does not occur again when the second transmission frame is sent.

Problems to be Solved by the Invention However, in such a conventional data transmission system, there are cases where the amount of processed data to be transferred is large, or when data transfer is performed by a terminal device 3 with a slow processing speed. In this case, the single bus 1 connected between the terminal devices 3 will be occupied for a long time, and other terminal devices 3 that are trying to transfer data to the same time will use the single bus 1. cannot be used. Therefore, operations other than data transfer, such as control commands with short bus dedicated time and their responses (
In other words, even the exchange of (command data) is made to wait, resulting in a problem that the operating efficiency of each terminal device 3 is reduced.

The present invention was made in view of these conventional problems, and its purpose is to provide a data transmission system that can transmit and receive processed data and command data in parallel, and achieve high-speed transmission. and enable effective data transmission.

Means to Solve the Problems In order to achieve the above objectives, the F3A of this invention has a data path for transferring data to be processed between multiple terminal devices, and a command line for passing command data consisting of control commands and their responses. The gist is a communication control device for a data transmission system that is provided with a central control means that connects a command line K and controls the flow of command data on the command line.

When transmitting data from one terminal device to another, control commands and responses are exchanged via a command line, and data to be processed is transferred via a data path under the control of a central control means. Let's do it. This not only improves the usage efficiency of the data path, but also shortens the waiting time for the terminal device to use the data path, thereby improving the operating efficiency of the terminal device.

Embodiment FIGS. 1 to 3 are diagrams showing a communication control device of a data transmission system according to an embodiment of the present invention.

In this control device, 11 is a central control device that centrally manages the transfer of control commands and responses in the data transmission system and the usage status of the data bus, and 12 is a terminal device that mutually transmits data. , 13 is a command line through which command data consisting of a control command and a response flows between the terminal device 12 and the star coupler 11, and 14 is a data bus through which data that can be processed flows between the terminal devices 12.

The star coupler 11 has a central processing unit, that is, a CPU 15, a command communication port 17 connected to the command line 13 for transmitting and receiving command data, and a command bus 16 for transferring command data between the command communication port 17 and the CPU 15. Consists of. Command communication boat 17Vi Star coupler 11 is installed for the number of terminal devices 12 to be connected upwardly, and each terminal device 12a
, 12b, and 12c are assigned channel numbers (command communication ports 13a, 13b, and 13c), respectively.

The terminal device 12 includes a command communication boat 18 that is connected to the command line 13 and exchanges command data with the star coupler 11, a CPU 19 that performs data processing and control within the terminal device 12, and a CPU 19 that performs data processing and control within the terminal device 12.
or each terminal device @12&, 12b, 12c
A memory 20 that stores data transferred between the two; a driver/receiver 22 that sends and receives data transferred via the data path 14; A data communication boat 21 that passes data from the memory 20 to the driver receiver 22 and writes data received from the driver register/922 to the memory 20, and a terminal device 12.
In the communication control device of the data transmission system having such a configuration, which includes a path 23 provided for exchanging data between the CPU 19 in the intermediate section and the other operating sections 18, 20, and 21, the communication control device between the terminal devices 12 When performing data transfer, a case in which data is transferred from the terminal device 12c to the terminal device 12b according to an instruction from the terminal device 12a will be explained. In Figure 2, vertical lines 11, 12a, 12
b, showing the 12cn star coupler and each terminal device,
14 is the exclusive state of the data path, and the part in the figure is the data path.
Indicates that the path is in exclusive use. Also, the code a = f is a terminal control command, a' to 1' are responses to it,
Communication is performed using command line 1a. gh de day
Shows data transfer using paths. The frame structure of this command line is schematically shown in FIG. Areas A and B of this frame 24 contain the channel number assigned to the command communication port 17 on the star coupler and the channel number assigned to the star coupler itself. Of these, area AK is the channel number of the destination of the control command or response, and area BK is the channel number of the source.
Enter the channel number. Area C contains control commands or responses.

Normally, processing between the terminal devices 12a, 12b, and 12a is performed by communicating control commands a"f and responses a' to f'. During this communication, the terminal device 12a on the command side
14 Command communication of the frame configuration data shown in Figure 3;
It is passed to the command communication boat 17a of the star coupler 11 via the command line 13 using the F NEET 18a.

When the CPU 15 of the star caffle 11 receives the command communication port 17aVc, it transfers the received data to the command communication port f7c of the destination channel number A, and transmits the data to the destination terminal device 12c through the command line 13C. During the above processing (Fig. 2 a)
=b, a'~b')i, the data path 14 is not used (FIG. 2, 14), and it is possible for other terminal devices to use the data path 14. Furthermore, by setting the channel number of the transmission frame (FIG. 3) to that of the star coupler 11, communication of control commands and responses is performed between the terminal device 12 and the star coupler 11 (FIG. 2, c
= f, c'-f').

This case is mainly performed when using the data path 14. When a large amount of data is transferred using the data path 14, the data is transferred directly between the driver and receiver 22 of each terminal device 12a, 12b, and 12c without passing through the star coupler 11 in the data path. At that time, if a plurality of terminal devices 12 try to transmit and receive data at the same time, a data collision will occur on the data path 14, so the star coupler 11 manages the use of the data path 14. In this embodiment, a terminal device (FIG. 2 12a
) transmits data reception reserve money a to the terminal device 12c that is the source of the data to be transferred and the terminal device 12b that is the destination of the data, upon receiving a take transmission preparation command, which is the terminal control portion, respectively. The terminal device 12c, which has received the data transmission preparation command, checks whether the data in the memory 20 can be transferred and the amount of data, and returns a response b' indicating that the control is busy. Further, the terminal device 12b that has received the data reception preparation command a checks whether the memory 2o can store the received data or not, and returns a response a' to the control command. The terminal device 12a, which has received the above responses d' and b', transmits a data path transfer control command C to the star coupler IIIC. This control instruction CKI-1, its frame header C
The channel numbers of the terminal devices that are the sender and receiver of the data to be transferred are written in . The star coupler 11 that has received the data path transfer command C checks whether the data path 14 is already in use, and if it is in use, it waits for the control command C received later, and transfers the data path 14 by the previous transfer operation.
When the use of 4 is completed, the next data ') data path exclusive use by overcontrol instruction C' is recorded in the next data. Then, the star coupler 11 first sends a data reception start command d to the terminal device 12b, which is the data reception destination specified by the i control command C.
Send. The terminal device 12b that received all the control commands d
The CPU 19 immediately instructs the data communication port b to set the driver/receiver 22 to the receipt window, and
4, the data is received from memory 20, and the response a l=1. Send. Upon receiving the response d', the star force 7 plastic 11 immediately transmits a data transmission start command e to the designated data destination terminal device 12c using the control command C. The (:PU20fl) of the terminal device 12c that received the control command e immediately instructs the data communication port 21 to set the driver/receiver 22' (i-transmission) and transmits the transfer data in the memory 20 to the data/processor 14 ( Second
Figure, g). When the data source terminal device 12ct/'i finishes transmitting the data, it causes the data communication port 21 to stop processing and sends a response θ to the star coupler 11 indicating the end of data transfer.
Send ′. Upon receiving the data transfer end response e', the star caffle 11 immediately sends the data to the data receiving terminal device 12b.
A data reception end command f is sent to the host. Upon receiving the data reception termination command I, the data reception destination terminal device 12bfl immediately stops the data communication boat 21, and
A reception end response 1' is transmitted to the coupler 11. Star
When the coupler 11 receives the reception end response f', it determines that the data transfer process has ended, releases the exclusive use of the data path 14, and sends a data transfer end response C' to the terminal device 12a that has instructed the above data transfer. , if there is a control command C waiting for the next data transfer, then the next data transfer process is started. This transmission and reception of the control command C is performed in parallel with the data transfer described above using a command line 13 provided separately from the data node 14.

As described in detail of the invention, the single-source F3A centrally manages a command line through which terminal control commands and responses pass through multiple terminal devices, a data path for transferring large amounts of data, and these data paths. By connecting with a star coupler, terminal control commands, etc. can be sent and received in parallel, and data can be transferred in parallel.The star coupler, which is the central control unit, manages the data path usage timing. The effect of improving the usage efficiency of the terminal device and the operating efficiency of the terminal device can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a communication control device of a data transmission system according to an embodiment of the present invention, and FIG. 2 is a control command and response when data is transferred by the communication control device of FIG. FIG. 3 is a conceptual diagram of communication, FIG. 3 is a configuration diagram of a frame of command data, and FIG. 4 is a schematic block diagram showing an example of a communication control device of a conventional data transmission system. 11... Star Kaffri (central control unit),
12...Terminal device, 13...Command line, 14...Data path, 15...
・CPU, 17.18...Command communication port, 19...CPU120...Memory, 21.
...Data communication boat, 22...Driver receiver. Name of agent: Patent Attorney Toshio Tsuchio, and one other person Figure 2, Figure 3, Figure 4 Axis

Claims (1)

[Claims] A plurality of terminal devices that exchange data with each other, a command line that exchanges command data consisting of terminal control commands and responses, a data path through which processed data is transferred, and data flow on the command line and data path. communication in a data transmission system, characterized in that data to be processed is transferred via a data path, and at the same time command data is sent and received between terminal devices via a command line. Control device.