KR100241557B1 - Data processing method of dual network - Google Patents

Abstract

According to the present invention, the data of the same frame is simultaneously transmitted to both network lines in a redundant state of the network line, so that even if a failure occurs in one network line, continuous data transmission and reception is possible without interruption in work through the other network line. It relates to a data transmission and reception processing method. The present invention includes the steps of: (a) waiting for reception of data on the first and second network lines; (b) if there is reception of data through at least one network line, determining whether the data is transmitted for both sides; (c) setting a message corresponding to "one network normal reception" when the currently received data is data transmitted for only one network line as a result of the determination in step (b); (d) if the current received data is data transmitted for both network lines as a result of the determination in step (b), determining whether the same data is received through the remaining network lines within a predetermined time; ; And (e) if the same data is received through the remaining network lines within the predetermined time as a result of the determination in step (d), set a message corresponding to "normal reception of both networks," and set no data. If not, it comprises the step of setting a message corresponding to "normal reception of only one side of both networks."

Description

Data Transmission / Reception Process in Redundant Network

The present invention relates to a data transmission / reception processing method of a redundant network, and more particularly, to a data transmission / reception processing method of a redundant network that can be applied to application software based on a client / server environment so that it can process business stably without interrupting data. will be.

Recently, thanks to the development of computer communication, a model that can exchange data with a computer far away from one's own computer and internal or public network has been proposed and actively used.

One such computer communication model is the client-server model. This client-server model is a server, a computer (hardware or software) that is responsible for centrally managing and providing information or resources, and a client (hardware or software) that is a computer (hardware or software) that is required to use such information or resources. It is a method of efficiently executing one application software by connecting a client by a network such as a local area network (LAN) or a wide area network (WAN). The client-server model is currently widely adopted in window systems and database management systems, and the client-server model is also adopted in various industrial monitoring and control systems.

On the other hand, the monitoring / control system generally builds its own independent database to read the MMI (Man Machine Interface) node that performs the monitoring / control of engineering-related tasks and facilities corresponding to the system configuration, and reads input / output contact points of actual sites. Or a control node equipped with a real-time operating system for outputting a control signal, various field devices connected thereto, and an alarm / notification device for conveying the status of each event to an operator.

Hardware diagram of the conventional client / server network model of FIG. As shown in Fig. 1, in the conventional client / server network model, various personal computers (hereinafter, simply referred to as PCs) are connected to a single network line 4 such as Ethernet, which is a representative LAN. ), A workstation 2 and various devices having a network function, for example, a programmable logic controller (hereinafter simply referred to as a PLC) 3 and the like. In addition, all devices 1, 2, and 3 on the above-described network line 4 are each equipped with one network card 5 to enable transmission and reception of data through the network line 4. . The main content of data transmission and reception proceeds mainly by providing data on the server side for data requests on the client side.

Therefore, if a failure such as a short circuit or poor connection of a single network line or a failure occurs in the network card, transmission and reception of data through the network line is virtually impossible, that is, the client cannot receive any further service from the server. Furthermore, it is difficult to diagnose what caused the network problems.

In this case, as a result, the client / server function is lost. Therefore, the program has to be restarted after detecting a network failure. Of course, there was a problem that the transmission and reception of data between the client and the server itself was impossible during the time when the network failure occurred and the time when the program was run again. As such, the network under the client / server environment affects the system as a whole, so that the economic loss due to the paralysis until the network is normally restored has a problem that increases proportionally. In particular, if the program is applied to a very important task, the network failure has a problem that puts a heavy burden on the real user.

In consideration of these problems, a so-called duplex-typed redundant network model in which network lines connected to respective devices are duplicated has been proposed. In this duplex redundant network model, only one network line is normally used, but the other network line is used only when the network line fails, and data loss occurs while the network line is taken over. In application software, there was a problem that it was difficult to adopt.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem, and in the redundant state of the network line, data of the same frame is simultaneously transmitted to both network lines, thereby interrupting work through another network line even if one network line fails. It is an object of the present invention to provide a data transmission / reception processing method of a redundant network that enables continuous data transmission / reception without an error.

The present invention for achieving the above object is a data transmission / reception processing method of a redundant network by connecting a variety of devices constituting the client / server model to the first and second two network lines, (a) the Waiting for reception of data on the first and second network lines; (b) if there is reception of data through at least one network line, determining whether the data is transmitted for both sides; (c) setting a message corresponding to "one network normal reception" when the currently received data is data transmitted for only one network line as a result of the determination in step (b); (d) if the current received data is data transmitted for both network lines as a result of the determination in step (b), determining whether the same data is received through the remaining network lines within a predetermined time; ; And (e) if the same data is received through the remaining network lines within the predetermined time as a result of the determination in step (d), set a message corresponding to "normal reception of both networks," and set no data. If not received, characterized in that it comprises the step of setting a message corresponding to "normal reception of only one side of both networks."

In the above configuration, when new data is received through the remaining network lines in step (e), a message corresponding to "normal reception of only one of both networks" is set. In addition, the determination in step (b) may be performed by analyzing header information of the data.

Hardware diagram of the conventional client / server network model of FIG. 1,

2 is a hardware configuration diagram of a client / server network model to which a data transmission / reception processing method of a redundant network of the present invention is applied;

3 is a flowchart for explaining a data transmission / reception processing method of a redundant network of the present invention.

*** Explanation of symbols for main parts of drawings *

1: PC, 2: workstation,

3: PLC, 4: network line,

5: network card, 10: first network line,

11: second network line, 12: first network card,

13: 2nd network card

Hereinafter, a data transmission / reception processing method of a redundant network according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a hardware configuration diagram of a client / server network model to which a data transmission / reception processing method of a redundant network of the present invention is applied. The same reference numerals are given to the same parts as those shown in FIG. . In FIG. 2, reference numeral 10 denotes a first network line, and 11 denotes a second network line. Thus, in order to solve the above-described problem, the present invention duplicates the network line. In addition, in order to support such a redundant network, two network cards 12 and 13 are mounted on each of the PCs 1 and the workstations 2 and the PLC 3 having a network function. have.

As described above, in the present invention, even if a fault occurs in any one of two network lines by allowing a network, data can be transmitted and received to the other network line. In addition, unlike the conventional duplex type, the same frame is always transmitted to the first and second network lines 10 and 11 described above. That is, both network lines 10 and 11 operate in an active state.

Table 1 below shows the software configuration of the transmission and reception processing module of the redundant network line according to the present invention.

Redundant Processing Layer First transmit / receive processing layer Second transmit / receive processing layer First transmit / receive buffer Second transmit and receive buffer First network layer Second network layer

As shown in Table 1, the software of the transmission / reception processing module of the redundant network line according to the present invention may be transmitted / received through the first network layer, the first network line 10 in charge of the communication through the first network line 10. A first transmission / reception buffer for temporarily storing data, a first transmission / reception processing layer responsible for transmitting / receiving data through the first transmission / reception buffer, a second network layer for communication over the second network line 11, a second network A second transmission / reception buffer for temporarily storing data to be transmitted / received via line 11, a second transmission / reception processing layer responsible for the transmission / reception of data through the second transmission / reception buffer, and data processed by the first and second transmission / reception processing layers It consists of a single redundancy processing layer that processes according to a predetermined rule to select the appropriate data.

In the above-described configuration, the data selection rule of the redundancy processing layer is regarded as normal data only when, for example, both network lines 10 and 11 receive the same data, and in this case, the first network line 10 The final frame is determined as the final data, and when data is received through only one network line, an appropriate process may be performed after an error check on the failed network line.

3 is a flowchart for explaining a data transmission / reception processing method of a redundant network of the present invention. As shown in FIG. 3, in step S10, each of the first transmit / receive buffer P_B and the second transmit / receive buffer S_B waits to receive data at the same time. In this waiting state, step S12 determines whether data has been received in each of the transmission and reception buffers P_B and S_B. If data is received in at least one of the transmit / receive buffers P_B and S_B in step S12, the flow proceeds to step S14, where the currently received data is stored in both transmit / receive buffers P_B and S_B. Determine if it was sent. This step S14 may be performed by analyzing header information of the received data.

If the data received in step S14 is not transmitted to both transmit / receive buffers P_B and S_B, that is, the data is transmitted to only one of the buffers, the process proceeds to step S16 to indicate that Set the message corresponding to "normal network reception" and send it to the redundancy processing layer. As a result of the determination in step S14, if the currently received data is data transmitted to both the transmission / reception buffers P_B and S_B, the process proceeds to step S20 and the transmission / reception buffer which has already received the data waits. Will be in a state.

Next, in steps S22 and S28, it is determined whether the remaining transmission / reception buffers that have not received data have received data of the same frame within a predetermined time t. When the data of the same frame is received in the remaining buffers in step S22, the process proceeds to step S24, after setting a message corresponding to "normal network reception", and sends it to the duplication processing layer. On the other hand, when the determination result in step S22, if the data of the same frame is not received in the remaining buffer, the process proceeds to step S26 to determine whether the data of the new frame is received. As a result of the determination in step S26, when the data of the new frame is received in the remaining buffer, the flow advances to step S30 to set a message corresponding to "receive one frame of both networks" and duplicate the first received frame. Send it to the layer. As a result of the determination in step S22, step S26 and step S28, if even the data of the new frame is not received in the remaining buffer for a predetermined time t, the process proceeds to the step "one of both networks. Set the message corresponding to "Receive frame" and send the frame received from one buffer to the redundancy layer.

The data transmission / reception processing method of the redundant network of the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea of the present invention. In other words, it can be widely applied to the network of all application software that uses TCP / IP and Ethernet.

According to the data transmission and reception processing method of the redundant network of the present invention as described above, by implementing the redundancy of the network line, even if a failure occurs in one network line, it is possible to continuously transmit and receive data through the other network line without interruption.

In addition, the data of the same frame is simultaneously transmitted to the redundant network line, so that there is no loss of data in the process of taking over the network line as compared with the duplex network of the existing duplex type, and thus it is good for the communication model that handles important tasks. There is an effect that can be applied.

Claims (3)

In the data transmission / reception processing method of a redundant network in which various devices constituting the client / server model are connected by two first and second network lines, (a) waiting to receive data on the first and second network lines; (b) if there is reception of data through at least one network line, determining whether the data is transmitted for both sides; (c) setting a message corresponding to "one network normal reception" when the currently received data is data transmitted for only one network line as a result of the determination in step (b); (d) if the current received data is data transmitted for both network lines as a result of the determination in step (b), determining whether the same data is received through the remaining network lines within a predetermined time; ; And (e) If the same data is received through the remaining network lines within the predetermined time as a result of the determination in step (d), set a message corresponding to the "normal reception of both networks" and receive no data. If not, the method comprising the step of setting a message corresponding to "only one side of both networks normal reception" data transmission and reception processing method comprising a. The method of claim 1, further comprising: (e ') setting a message corresponding to "normal reception of only one of both networks" when new data is received through the remaining network lines in step (e). Data transmission and reception processing method of a redundant network, characterized in that made. The method according to claim 1 or 2, wherein the determination in step (b) is performed by analyzing header information of the data.

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