JPH10224385A - Data processing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To omit a data switching hardware for the scale simplification and to improve the reliability and processing speed of a data processing system by receiving the data on both transmission lines and applying the data on the normal transmission line if the data on the other line have an error. SOLUTION: This system consists of the devices 1 and 2 which are corresponding to the data transmission lines included in a LAN transmission line 3 and simultaneously send the same data to both corresponding transmission lines, and the external equipments 4-1 to 4-3 which contain the receiving circuits to receive the data which are simultaneously sent from both devices 1 and 2. If abnormality of the main data is detected based on the monitoring result of parity check, etc., acquired by a monitoring circuit, the equipments 4-1 to 4-3 receiving the data from the devices 1 and 2 process the data (redundant data) as the new main data out of those data which are received by both receiving circuits.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data processing system, and more particularly to a data processing system for processing data on one of main and redundant data transmission lines.

[0002]

2. Description of the Related Art Conventionally, this type of data processing system has
In order to acquire the data with higher reliability, the data status of the main system and the redundant system is monitored, and the transmission paths of the main system and the redundant system are switched. In that case, it has been configured to include a switching device for switching the transmission path.

FIG. 4 is a block diagram showing a configuration of a conventional data processing system. In the figure, a conventional data processing system includes redundant main and redundant devices 1 and 2, a switching device 5 that receives data output from these devices 1 and 2 as input, and outputs one of them. An external device 4 that receives data output from the switching device 5 as input and performs processing on the input data is configured. As shown in the figure, it is assumed that the devices 1 and 2 and the external device 4 are each composed of a main body and a display monitor.

In such a configuration, one of the data output from the devices 1 and 2 is used as main data,
The other is used as redundant data, and the main data is output to the external device 4 in normal times. When an error occurs in the main data, the switching device 5 switches the data, switches the main data to the redundant data, and continues data transmission.

[0005]

In the above-mentioned conventional data processing system, the switching from the main system data to the redundant system data is performed by hardware (switching device). There is a disadvantage that the reliability of the device decreases.

In Japanese Patent Application Laid-Open No. Hei 4-92526,
Switching is performed by hardware, and has the same disadvantages as in the case of the system of FIG. 4 described above. Further, in Japanese Patent Application Laid-Open No. 64-74444, communication is merely performed without being aware of duplexing, and the above-mentioned disadvantages of the prior art cannot be solved.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and has as its object to provide a data processing system capable of improving reliability by eliminating hardware for switching data. It is.

[0008]

SUMMARY OF THE INVENTION A data processing system according to the present invention includes first and second data transmission lines which are provided in correspondence with first and second data transmission lines and transmit the same data simultaneously to the corresponding transmission lines. A second data transmission device and the first
And first and second receiving means provided corresponding to the respective data transmission lines and receiving data of the corresponding transmission lines, respectively, and any one of data received by the first and second receiving means. A data receiving apparatus having processing means for performing processing using the other received data when an error occurs in one of the data receiving apparatuses.

In short, the data processing system receives data of a plurality of transmission lines respectively, and when an error occurs in the received data, employs the data having no error. This eliminates the need to provide hardware for switching data, simplifies the scale of the system, and improves reliability and processing speed.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a data processing system according to the present invention. In the figure,
4 are denoted by the same reference numerals, and detailed description of those portions will be omitted.

Referring to FIG. 1, a data processing system according to an embodiment of the present invention includes a LAN (Local Area).
Network 1) and 2 that are provided corresponding to the data transmission lines included in the transmission path 3 and simultaneously transmit the same data to the corresponding transmission lines, respectively.
And 2 have external devices 4-1, 4-2, and 4-3 each having a receiving circuit for receiving data transmitted at the same time.

In such a configuration, as a result of transmitting the same data from the devices 1 and 2 simultaneously, the LAN transmission line 3 transmits the same data in parallel. This L
Data transmitted by the AN transmission line 3 is transmitted to an external device 4-
i (i = 1 to 3; the same applies hereinafter).

In order to simultaneously receive data from the devices 1 and 2 transmitted in parallel, a receiving circuit corresponding to each data is provided in the external device 4-i. Each of the external devices 4-i receives data from the devices 1 and 2 at the same time. Normally, one of the data is adopted as the main data and processed. The other data is a redundant system (standby system).

In each external device 4-i, it is always monitored whether or not there is an error in the main data. When an error occurs in the main data, redundant data is adopted as new main data instead of the main data, and is used as a processing target. Monitoring whether there is an error in the data is performed by using a well-known parity check or redundant code check (CRC; Cycle).
c Redundancy Check).

As described above, in this system, both the main system data and the redundant system data are received, and if an abnormality occurs in the main system data, the redundant system data is used as new main system data. No hardware is used. That is, since the data is switched by software without using hardware, the reliability of the system is improved.

Here, the internal configuration of each external device 4-i will be described with reference to FIG. The figure shows each external device 4-i
2 is a block diagram showing an example of the internal configuration of FIG.

In FIG. 1, an external device 4-i is provided corresponding to the data transmission lines 3-1 and 3-2 included in the LAN transmission line 3, and transmits data transmitted by the corresponding data transmission lines. Receiving circuits 41 and 42 for receiving data, and a CPU (Central) for receiving data received by these receiving circuits 41 and 42 and processing one of them.
(Processing Unit) 40 and a monitoring circuit 43 provided in correspondence with the receiving circuits 41 and 42 and monitoring an error of data received by the corresponding receiving circuit.
And 44 are included.

The CPU 40 employs one of the data received by the receiving circuits 41 and 42 as main data and performs processing such as writing to a hard disk (not shown).

The monitoring circuits 43 and 44 constantly check the data received by the receiving circuits 41 and 42.
Then, if there is an error in the data, the CPU 40 is interrupted. In response to this interrupt, the CPU 40 employs the redundant data as new main data. As described above, since data is switched by software without using hardware, the reliability of the system is improved.

In general, the form of the LAN transmission path is as follows.
In addition to the bus type described above, there are a star type and a ring type. In the case of the bus type described above, it is easy to add, change, or modify each device or device. A star-type or ring-type LAN transmission line may be used unless additional devices are considered.

Next, the operation of each external device in the data processing system will be described with reference to FIG. FIG. 5 is a flowchart showing the operation of each external device.

As shown in FIG. 1, each external device receives data transmitted from the devices 1 and 2 by two receiving circuits, respectively, and uses one of them as main data and the main data. Is the target of processing (step 31). The data received by the receiving circuit is monitored by the monitoring circuit, and the main data is processed as long as no abnormality occurs (steps 32 → 31...).

As a result of the monitoring by the monitoring circuit, if an abnormality occurs in the main data, the other of the data received by the two receiving circuits (redundant data) is used as new main data. The main data is processed (step 33). The data received by the receiving circuit is monitored by the monitoring circuit, and the main data is processed as long as no abnormality occurs (steps 34 → 33...).

As a result of monitoring by the monitoring circuit, if an abnormality occurs in the main data, the other data is processed as new main data as long as the other data is normal (steps 34 → 31...). ).

As described above, in the present system, the data is monitored by software, and if an error occurs in the main system data, the data is switched to the redundant system by software. Less, and the reliability of the system is improved.

The present invention can take the following aspects in connection with the description of the claims.

(1) The data processing system according to any one of claims 1 to 3, wherein the error detecting means detects the received data error by parity check.

(2) The data processing system according to any one of claims 1 to 3, wherein the error detecting means detects the received data error by checking a redundant code.

[0030]

As described above, according to the present invention, data of a plurality of transmission lines is received, and when an error occurs in the received data, the data having no error is adopted. This eliminates the need for hardware for switching data, simplifies the scale of the system, and improves the reliability and processing speed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a data processing system according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of each external device in the data processing system of FIG.

FIG. 3 is a flowchart illustrating an operation of each external device in the data processing system of FIG. 1;

FIG. 4 is a block diagram showing a configuration of a conventional data processing system.

[Explanation of symbols]

 1, 2 device 3 LAN transmission line 4 external device

Claims (3)

[Claims] A first and second data transmission device provided corresponding to each of the first and second data transmission lines and transmitting the same data to the corresponding transmission lines simultaneously; and the first and second data transmission devices. 1 and 2 for receiving data of the corresponding transmission lines respectively provided for the two data transmission lines.
And a data receiving device having a processing unit for performing a process using one of the data received by the first and second receiving units when an error occurs in the other of the received data. A data processing system, characterized in that: 2. The processing means according to claim 1, wherein said processing means includes an error detecting means for detecting errors in the data received by said first and second receiving means, respectively. 2. The data processing system according to claim 1, further comprising means for performing. 3. The data processing system according to claim 1, wherein the first and second data transmission lines are included in a bus line.