JPH01251257A - Data communication system - Google Patents

Abstract

PURPOSE:To promote a work processing of each station computer by avoiding a program execution period of a slave station and updating the contents of a main memory by setting a program stored in a memory card, as an object. CONSTITUTION:Memory cards 11-14 of each station STN 3-6 store temporarily a program which has been transferred through a data transmission line 1 in order to update the contents of main memories 7-10 from a master STN 2. Thereafter, a maintenance control device 16 sets the program stored in the cards 11-14, as an object, and updates the contents of the main memories 7-10 by avoiding a program execution period in computers of the STNs 3-6. Therefore, the computer program of the STNs 3-6 can be changed without stopping the processing operation in the computers of the STNs 3-6 which are executing the program. Accordingly, the work processing in the computers of the STNs 3-6 integrated into the system can be promoted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a data communication system including, for example, a LAN (Local Area Network System).

(Prior Art) In recent years, in the field of data communications, network systems that connect multiple independent computers and terminals using data communication lines have been attracting attention.

In particular, such systems are known in which a parent station and a plurality of slave stations are connected to a data transmission path such as a coaxial cable or an optical fiber cable.

By the way, in the above-mentioned system, in order to improve the functionality of the child station or to make some corrections to the parent station, it is necessary to change the program being used by transferring a change program from the parent station.

However, when making this program change, the processing operation will be stopped regardless of the execution of processing on the target child station side, so as a result, the business processing that was interrupted when the power is turned on again will be restarted from the beginning. The need had arisen.

Therefore, in such a network system, if a program change is to be made to multiple child stations, the above-mentioned processing operation stop and restart operation must be repeated for each child station, or a certain L'1 is The entire system was temporarily stopped and restarted.

Moreover, such operations are generally performed by inputting predetermined commands from a maintenance control device connected to the parent station, which places a heavy burden on the operator and is also prone to human command errors and other operational errors. There was a risk that this would cause confusion to the system.

Further, in such a program change method, a method is adopted in which the program to be changed is divided into sizes that can be transferred on a data transmission path, and each of these is transferred one by one to child stations.

Therefore, it takes a long time (
There was a problem that it took about 10 to 30 seconds).

(Problem to be Solved by the Invention) As described above, in the conventional network system, changes in the program used on the child station side are
Processing operations at the child stations must be stopped for long periods of time, making it difficult to always perform business processing efficiently at each child station.

The present invention is intended to solve the problems in conventional data communication systems such as the above-mentioned network system.It is an object of the present invention to quickly update the computer of a station by a simple operation without stopping the processing operation of the computer that is executing the program. The object of the present invention is to provide a data communication system in which the programs used can be changed and business processing can be promoted in the computers of each station incorporated in the system.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the data communication system of the present invention provides a data communication system in which a parent station and a plurality of child stations are connected to a data communication line. In the system, the parent station is provided with a change program transfer means for changing the execution program of the child station, a program storage means storing a program to be executed for each child station, and a change program transfer means for the parent station. Auxiliary storage means for temporarily storing programs transferred via a data communication line in order to update the contents of the program storage means, and programs stored in the auxiliary storage means to avoid the program execution period of the child station. and control means for updating the contents of the program storage means.

(Function) In the data communication system of the present invention, the auxiliary storage means of each station temporarily stores the program transferred from the parent station via the data communication line in order to update the contents of the program storage means. Since the post-control means updates the contents of the program storage means for the program stored in the auxiliary storage means while avoiding the program execution period in the child station computer, processing operations in the child station computer during program execution are updated. It is possible to quickly change the program used in the computer of a child station without stopping and with a simple operation, thereby promoting business processing in the computer of each child station incorporated in the system. .

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of a network system employing the data communication system of the present invention.

In the figure, 1 is a data transmission line made of, for example, a coaxial cable or an optical fiber cable, and 2 to 6 are stations connected to the data transmission line 1 in a loop through predetermined ink faces. .

Among these stations 2 to 6, one is the parent station 2 that has a host computer that is the parent in this system, and the others are the first to fourth child stations 3 to 6 that are children of this parent station 2. It is.

Further, 7 to 10 are main memories in which programs to be executed in each of the child stations 3 to 6 are stored, respectively; 11 to 10;
14 is a memory card which is an auxiliary storage means for temporarily storing programs transferred from the parent station 2 to update the contents of the main memories 7 to 10, and 15 is a floppy disk in which a change program is written. A floppy disk device (FDD) is used to read the program data from the main station 2, and 16 is a maintenance control device that selects processing operations of this system centered on the parent station 2.

Next, the operation of the program change process executed in this embodiment system will be explained with reference to the flowchart shown in FIG.

First, a floppy disk on which a change program has been written is set in the floppy disk device 15.

Next, the operator operates the maintenance control device 16 and inputs into the parent station 2 a software generation change message that reads, for example, "download to child station 5 of rffi3."

As a result, a software generation change message is sent from the parent station 2 to the third child station 5 (step 2
1).

Upon receiving this message, the third child station 5 sends a response message back to the parent station 2 (step 22).

When the parent station 2 receives this message, it controls the floppy disk device 15 and starts reading the data (change program) written on the floppy disk (step 23).

The read data is stored in a transfer data storage memory (not shown) inside the main station 2, and then cut out by a predetermined length for transfer and sent onto the data transmission path 1 ( Step 24).

Thereafter, the third slave station 5 that has retrieved the data from the data transmission path 1 starts writing the data into the storage element in the memory card 13 (step 25).

When data writing is completed at the third child station 5, a reception completion message is sent to the parent station 2. Upon receiving this message, the parent station 2 examines the transferred data storage memory and determines whether the remainder of the program being transferred still exists in that memory (step 26).

If it is determined that the program remains, the parent station 2 further cuts out a predetermined length of data from the remaining program and sends this data again to the child station 5 of node 3 (step 24).

Therefore, the processes from step 24 to step 26 described above are repeated until the transfer of all the programs of the - group is completed.

Thereafter, when the parent station 2 determines that the transfer of the - group of programs has been completed, a program transfer completion message is sent to the third child station 5 (step 27).

The third child station 5 that received this message checks whether it is currently executing a processing operation using a program stored in the main memory 9 (step 28).
The next action is determined based on the result.

If the program is being executed, the program waits for the processing operation to end; if the program is not being executed, the program is immediately changed in the main memory 9, targeting the data stored in the memory card 13 (step 29).

When the program change in the main memory 9 is completed, the third child station 5 then sends a program change completion message to the parent station 2 (step 30).

The parent station 2 receiving this message checks whether the next set of programs to be transferred remains (step 31), and if it does not exist, ends the program change processing operation. If the next set of programs exists, the processes from step 24 to step 31 described above are executed in the same way, all programs are transferred, and the main memory 9 is
Change the program.

Thus, according to the network system of this embodiment,
Since program changes in child stations 3 to 6 are made to the programs stored in the memory elements of memory cards 7 to 10, avoiding the program execution period, each time a program change is made, the currently executing child There is no need to stop the processing operations of the stations 3-6, and as a result, business processing at each child station 3-6 can be promoted.

Although this embodiment has described a method for changing the entire program, it is also possible to easily change part of the program table by table by specifying the memory address of the changed part using the maintenance control device 16. Can be done.

Further, in the present invention, the auxiliary storage means is not limited to the memory card 7.8.9.10, but an external storage device such as a floppy disk device may also be used.

[Effects of the Invention] As explained above, according to the data communication system of the present invention, a program can be used in a child station computer quickly with a simple operation without stopping the processing operation in the child station computer during program execution. Programs can be changed, thereby promoting business processing in the computers of each child station built into the system.

[Brief explanation of the drawing]

Fig. 1 is a block diagram for explaining the configuration of a network system that is an embodiment of the data communication system of the present invention, and Fig. 2 shows the flow of operations for changing programs in the network system of Fig. 1. FIG. 1... Data transmission path, 2... Parent station, 3...
...First child station, 4...Second child station, 5...Third child station, 6...Fourth child station, 7-10...Main memory, 11-14
...Memory card, 15.. Floppy disk device, 16.. Maintenance control device. Applicant Toshiba Corporation Representative Patent Attorney Sasa Suyama −

Claims (1)

[Claims] (1) In a data communication system in which a parent station and a plurality of child stations are connected to a data communication line, the parent station is provided with a change program transfer means for changing the execution program of the child stations; A program storage means storing a program to be executed by each child station, and a program transferred from the change program transfer means of the parent station via the data communication line in order to update the contents of the program storage means. It is characterized by comprising an auxiliary storage means for temporarily storing the program, and a control means for updating the contents of the program storage means for the program stored in the auxiliary storage means, avoiding the program execution period of the child station. data communication system.