JPH08263400A - Communication control system - Google Patents

Abstract

PURPOSE: To provide the communication control system which enables plural computer systems connected in the multidrop form to simultaneously execute the different commands without an influence of noise or the like by adding a command execution synchronizing signal to a communication line. CONSTITUTION: Each of plural computers 2, 3,... connected in the multidrop form as objects to be controlled receives a command and temporarily stores the analysis result in a memory 22 and executes the corresponding processing at the time of detecting that the command synchronizing signal from a computer on the control side is turned on.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication control system, and more particularly to a communication control system capable of simultaneously and reliably executing commands in a plurality of computers connected in a multi-drop type.

For example, in a large-sized display device, one display is divided into a plurality of display areas, and a plurality of display control units for individually displaying each divided area in blocks are provided. Many. In such a large-sized display device, the display by the block-by-block display control unit is controlled by the subordinate computer of each display control unit that receives the command sent from the superordinate computer. That is, it is necessary to perform synchronized display control such as simultaneous display and blinking on a block-unit computer connected in a multi-drop type.

Generally, in a computer system connected in a multi-drop type, when a plurality of connected computers are caused to execute different commands, the conventional communication control system sequentially processes each computer. That is, after transmitting the command to one computer, the command is transmitted to the next computer, and then the command is transmitted to the next computer.

[0004]

However, in such a communication control system, when it is necessary to cause a computer connected to a plurality of computers to simultaneously execute a command as in the above-described large-sized display device, one computer, one computer, and one computer Since the process of transmitting a command to the machine is required, an error for the transmission time will always occur, and simultaneous execution is impossible.

On the other hand, a system has been proposed by the applicant of the present application in which a control station sends a collective control execution command in order to execute control to all controlled stations all at once (Japanese Patent Application Laid-Open No. 04-162899). .

In the above-mentioned conventional communication control system, when the connected lower-level computer receives an execution command, it executes the command at its own timing, so that a plurality of connected devices are connected as in the large display device. There is a problem that an error always occurs when the computer needs to execute the commands at the same time.

Further, in the technique disclosed in Japanese Patent Laid-Open No. 4-162899 using the collective control command, when noise occurs on the transmission line, a lower-level computer that cannot receive the collective control command is generated due to the noise or the like. Sisters,
There was a problem that the necessary processing could not be executed on that computer.

[0008]

In order to solve the above-mentioned problems, the communication control system according to the present invention sends data from a computer on the control side to a plurality of computers to be controlled which are connected in a multi-drop type. In the communication control method for executing command processing corresponding to the command, each of the plurality of computers receives the command, temporarily stores an analysis result in a memory, and outputs a command synchronization signal from the controlling computer. Is configured to execute corresponding processing in response to the detection of ON of.

Here, the command is a computer address which is a physical address for identifying each of the plurality of computers, a command code which is an individual command or a simultaneous execution command, and a detailed data portion which is added to the command processing. Has a detailed data section that is
In addition, the ON detection of the command synchronization signal can be determined to be ON detection only when ON is detected for a predetermined time or more. Further, each of the plurality of computers checks the computer address specified by the command and confirms that it is a command for itself, and then executes the command processing or analyzes the command and executes the simultaneous execution command. When it is determined that the command contents are stored in the memory, detailed command data is stored in the memory, the command execution is put in a waiting state, a command reception response is returned to the control side computer, and ON of the command synchronization signal is detected. Then, the corresponding processing can be executed.

[0010]

In the present invention, each of the plurality of computers as the controlled objects connected in the multi-drop type is
The command is received, the analysis result is temporarily stored in the memory, and the command synchronization signal O from the control side computer is sent.
When N is detected, the corresponding process is executed. In other words, a synchronization signal is sent to a computer connected to multiple communication lines for processing at the same time, and commands are issued to the computers connected in a multi-drop type one after another. By synchronizing, it is possible to execute simultaneous processing.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a system configuration diagram of a communication control system of the present invention.

The upper computer 1 and the lower computers 2, 3, ..., N are connected via a multi-drop type communication line L. The high-level computer 1
An execution command is issued to the lower computers 2, 3, ..., N via the multi-drop type communication line L. The upper computer control unit 11 in the upper computer 1 selects a command to be issued to the lower computers 2, 3, ..., N, and controls the actual command issuing process.

The lower computers 2, 3, ..., N are connected to the upper computer 1 via the multi-drop type communication line L.
Receive execution command from. Lower computer 2,
, ..., N have similar configurations as described below.

The control unit 21 of the lower computer 2 instructs the execution processing unit 23 in the computer to analyze and execute the execution command received from the upper computer 1.
The storage unit 22 temporarily stores the data of the execution waiting command and the like. The execution processing unit 23 receives the execution instruction from the control unit 21 and executes the actual processing of each command.

An example of the format of the command used in the communication control system in this embodiment is shown in FIG. 2. C1 is a computer address part, which is a physical address for identifying a lower computer. C2 is a command code part. The command includes an individual command or a simultaneous execution command, and the lower-level computer analyzes the command to make a determination. A detailed data section C3 is added by the higher-level computer when the detailed data is required for the command processing instructed, and the lower-level computer executes the content specified by the detailed data.

FIG. 3 is a block diagram of a signal line used in the communication control system of this embodiment. S1 is a transmission data signal from a high-order computer, S2 is a reception data signal from a low-order computer, and S3 is the present implementation. It is a command execution synchronization signal for a simultaneous execution command used in the example. When this command execution synchronization signal is turned ON, all lower computers can execute commands simultaneously.

The communication control system of this embodiment will be described below with reference to FIGS. The upper computer 1 sends an execution command to the lower computers 2 to n. In the case of an individual command, the commands are sequentially executed from the computer that received the command.

On the other hand, when it is necessary to cause the lower computers 2 to n to simultaneously execute the command processing having different execution contents, the command execution is performed in the following procedure.

First, the upper computer 1 sends an execution command to the lower computers 2 to n.
The low-order computer that receives the command first checks the computer address and confirms that the command is for itself. Next, it is determined whether the received command code is an individual command or a simultaneous execution command. This determination process is performed by the control unit 21 of the lower computer.
By. After the command analysis, the detailed data is analyzed and the detailed command processing contents are confirmed.

Subsequently, when the received command is a simultaneous execution command, the lower computer control unit 21
Stores the command contents and detailed data in the storage unit 22, and puts the command execution into a waiting state.

Next, the command contents and detailed data are stored in the storage unit 22, and the low-order computer in the execution waiting state returns a command reception response to the high-order computer 1. By receiving the command reception response, the high-level computer 1 confirms that the low-level computer was able to receive the command normally.

Subsequently, when the high-order computer 1 finishes sending commands to all the low-order computers 2 to n,
The upper-level computer turns on the command execution synchronization signal. The command execution synchronization signal is distinguished from noise or the like by determining that it is turned on only when it has been on for a certain period of time. With such a determination, it is extremely unlikely that the lower computer cannot detect the synchronization signal.

Further, the lower-level computer, which confirms that the command execution synchronization signal is ON, instructs each execution processing section to execute each execution processing.

[0024]

As described above, according to the present invention, by adding the command execution synchronization signal to the communication line, different commands can be simultaneously applied to a plurality of computer systems connected in a multi-drop type so as to reduce the influence of noise or the like. It is possible to execute without receiving. The present invention is a computer system that requires a process such as simultaneous display or blinking of individual data in each block when a CPU is mounted on a block basis in a large display device or the like and controlled by a multi-drop type connection. Will be effective in.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing a communication control system of the present invention.

FIG. 2 is a diagram showing a command format used in the communication control system of the present invention.

FIG. 3 is a configuration diagram of a signal line used in the communication control system of the present invention.

[Explanation of symbols]

 1 Higher side computer 2, 3, ..., N Lower side computer 11,21 Control unit (lower side) 22 Storage unit 23 Execution processing unit

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Claims (5)

[Claims] 1. A communication control system for executing command processing corresponding to a command sent from a controlling computer to a plurality of computers to be controlled, which are connected in a multi-drop type, Each of the computers receives the command, temporarily stores an analysis result in a memory, and executes a corresponding process in response to detection of ON of a command synchronization signal from the computer on the control side. control method. 2. The command includes a computer address which is a physical address for identifying each of the plurality of computers, a command code which is an individual command or a simultaneous execution command, and a detailed data section which is added to the command processing. Claim 1 having a detailed data section
The communication control method described in. 3. The communication control system according to claim 1, wherein the ON detection of the command synchronization signal is judged as ON detection only when ON detection is made for a predetermined time or more. 4. Each of the plurality of computers comprises:
The communication control system according to claim 1, wherein the command processing is executed after checking the computer address specified by the command and confirming that the command is for itself. 5. When the command is analyzed and it is determined that the command is a simultaneous execution command, detailed data of the command is stored in a memory, a command execution is set in a waiting state, and a command is issued to the control side computer. The communication control method according to claim 2, wherein a reception response is returned, ON of the command synchronization signal is detected, and corresponding processing is executed.