KR100870712B1 - System and signal processing method for railway control network by means of switched ethernet - Google Patents

Abstract

The present invention relates to a network system for a railroad signal system requiring high reliability using switched ethernet. Switched ethernet, which supplements the random characteristics of the ethernet, is used to detect and recover a defect in the network. The present invention relates to a network system for a highly reliable railway signal control facility having a redundancy structure.

The system of the present invention includes a network interface card (NIC) connected to a plurality of railway signal control facilities and transmitting / receiving only normal data by repeatedly transmitting and receiving the same data through a plurality of ports and comparing the data. Switched Ethernet connected to a plurality of railway signal control facilities for transmitting and receiving the data, providing the data to the plurality of network interface cards, and switching data using a buffer, and transmitting and receiving data between the network interface card and the switched Ethernet. It includes an extra bus for.

Network interface card for railway signal control, fault-tolerant network.

Description

System and signal processing method for railway signal control facility using switched ethernet {System and signal processing method for railway control network by means of switched ethernet}

1 is a conceptual diagram of conventional Ethernet and switched Ethernet

2 is a block diagram of a network system for railway signal control equipment using switched Ethernet of the present invention;

3 is an example of a configuration of a multiport network interface card of the present invention.

Figure 4 is a block diagram of an example of the interface of the actual railway signal equipment using the present invention.

The present invention relates to a system for railway signal control equipment. In particular, it is easy to expand and use reliable signal processing using switched Ethernet, and provide a network capable of detecting and recovering a fault even when a fault occurs. A network system for signal control equipment.

In general, the railway signal system is located on the railroad side of the railway to handle speed control and course control of the train, and is a vital system that prevents the collision of the train and is finally responsible for the safe operation of the train. These signal control devices are linked to other control devices while performing their own functions, and constitute one signal control system.

Most of the links between conventional railway signal controllers use point-to-point communication, so only one device is connected to one control device when maintenance or addition of a new device is costly and time-consuming to expand. There is a lifting issue. In order to overcome the above problems, an effort to construct a network between the link between the railway signaling device is required.

Conventional point-to-point communication system can be more complicated due to the increase of communication cable with the increase of railway signal control device, and the link of each device should be added and deleted as needed. This has a disadvantage that is not easy.

In recent years, the importance of the network has increased as each device used in the railway signal system has become electronic. In addition, there is a need for a network technology capable of satisfying real-time requirements and reliability in a system requiring high reliability such as a railway signal system.

As mentioned above, most of the links between the control devices for railway signals currently use point-to-point communication, which is difficult to maintain when adding new devices. In order to solve this problem, if the interface between railway signal equipments is applied to Ethernet technology instead of the existing point-to-point communication, the transmission media can be shared to reduce the installation and maintenance costs, and to expand and add new devices. However, there may be a problem in securing safety and reliability of data transmission due to sharing of transmission media. Therefore, in order to apply network technology to interface between railway signaling equipment, a system that can guarantee the safety of data transmission is required.

An object of the present invention for solving the above problems is to build a network of railway signal system that requires high reliability by using a switched Ethernet, using a switched Ethernet that complements the random characteristics of the Ethernet, and causes a defect in the network The present invention provides a network system for railway signal control equipment using switched Ethernet, which is capable of constructing a network of high-reliability railway signaling system by making a redundant structure to detect and recover defects during construction.

In addition, the present invention provides a system for railway signal control equipment using a system having a redundant network structure of high reliability using a network interface card installed with two or four ports based on switched Ethernet. .

The system of the present invention includes a network interface card connected to a plurality of railway signal control facilities and transmitting and receiving identical data repeatedly through a plurality of ports, comparing and judging data, and transmitting and receiving only normal data, and the plurality of railway signal control facilities. A switched Ethernet for transmitting and receiving the data, providing the data to the plurality of network interface cards, and switching data using a buffer; and an extra bus for transmitting and receiving data between the network interface card and the switched Ethernet. It is characterized by including.

In addition, the method of the present invention for achieving the above object, in the railway signal system, receiving the data to determine the normal data and to transmit the data to the multi-system network device, the same data transmitted from one station Receiving each of the different from the switch, characterized in that the process of transmitting the data to the network interface card attached to the railway signal control facility.

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

It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted.

The present invention is capable of processing data in real time using switched Ethernet in a railroad signal system, constructing an extra parallel structure to improve the reliability of the entire network, and to control the railroad signal using switched Ethernet capable of identifying and recovering defects. Network system for facilities.

The Ethernet protocol is the most common network technology used in offices today, and if it is applicable to railway signals, it can realize a network system for railway signals very inexpensively and efficiently. However, Ethernet protocol is to retransmit after waiting for a random time when collision of transmission frames occurs.In Ethernet, it is impossible to accurately predict transmission delay, so strict hard real-time cannot be secured. It cannot be used for interfaces between railroad signal control facilities that require higher safety.

In the present invention, as one of methods for solving the uncertainty of the transmission delay of the transmission frame in Ethernet, it is intended to solve by introducing a switching technology to Ethernet.

Switching technology has been developed and applied mainly for office networks. However, as switching technology becomes more common and the price of switches decreases, attempts to apply switches to industrial networks are increasing.

Unlike conventional Ethernet, switched Ethernet operates as if a dedicated virtual line is established between two stations to communicate with, thus reducing the probability of collision between transmission frames.

1 is a conceptual diagram of conventional Ethernet and switched Ethernet.

In the Ethernet of FIG. 1 (a), when a frame is transmitted from a source station, the frame is transmitted to all stations. Conventional Ethernet as shown in FIG. 1 (a) has a problem in that a collision occurs in a hub because the base station transmits a data frame to all connected stations at the time of transmission.

In the switched Ethernet of FIG. 1 (b), a frame is transmitted only to a destination station, and a collision does not occur even when simultaneously transmitting to multiple stations. That is, switched Ethernet uses switching technology to avoid collisions in the switching hub, which can occur when two or more stations attempt to transmit frames to one destination station.

In addition, when switched Ethernet receives frames from the source station's transmit line, it checks whether the destination station's receive line is busy.

If the receiving line is not in use, it transmits immediately, but if the receiving line is in use, it is stored in the buffer of FIG. 1 (b) connected to the station and waits until the receiving line is finished.

In addition, when a plurality of frames having the same destination station are received in the switched Ethernet, they are stored in a buffer of each port of the switching hub of FIG. In this way, collisions occurring at the switching hub can be eliminated.

In the present invention, in order to apply switched Ethernet, which is used as an industrial network, to a railroad signal system requiring stability, a hardware redundant structure based on a multiport network interface card and a switch dual structure is applied to improve reliability.

In a rail signaling system, fault tolerance means a system designed so that failure of any part or module in the system does not interfere with the operation of the system. The fault-tolerant system aims to ensure that the system continues to operate normally in the event of any fault, without losing or destroying any data.

In general, in rail signal systems, where safety is very important, a fault-tolerant system with high reliability is absolutely necessary.

One important feature of maintaining fault tolerance is always copying and processing more than one piece of data. In other words, when data is generated in an application program, it is always stored in two memories and then transferred. If there is a problem with data in one module's memory, the one that maintains and transmits the two or more memories continuously and compares the data to find the correct data without affecting other systems at all. Fault tolerance can be maintained.

In the present invention, a new multi-port network interface card having two or four input / output ports in one network interface card for fault tolerance is used, and a plurality of communication ports and communication lines are used to construct a network system having fault tolerance. Is done.

According to the present invention, the same data is repeatedly transmitted and received using a multiport network interface card, and a plurality of switches are connected to each other redundantly to transmit and receive the same data as the network interface card. It transmits and receives a plurality of switches, and implements an extra bus in preparation for an error of communication line during data transmission and reception, and implements a stable railway signal system.

The schematic configuration of the railway signal system using the switched Ethernet of the present invention that can satisfy these requirements is as shown in FIG.

Referring to FIG. 2 (a), each station has a network interface card 20 having two ports, and each switch 30 is duplicated with the same message through the network interface card 20 of these two ports. Send and receive messages via

Switched Ethernet is a combination of network interface cards and switches.

For example, port 1 of the slave station 20 1 transmits and receives the same message to the switch 30 1 and port 2 to the switch 30 2.

The two switches 30 transmit and receive the same message to the master 40.

In this manner, a stable duplex structure can be formed by transmitting and receiving the same message using two ports in the network interface card 20 as one slave station.

In addition, when an error message is received, the network interface card 20 compares the message, removes the error message, and transmits and receives a message having a normal value.

In other words, when there is an error message by comparing two messages received from the switch, the receiving station outputs the final result value using the normal message.

Figure 2 (b) shows an example of a network system for the railway signal system that can be extended to four multi-port to secure more improved fault tolerance characteristics.

In addition, the redundant bus structure maintains the operation of the system stably because data can be transmitted / received through the normal bus even if a communication bus failure occurs.

Here, each slave station 20 transmits and receives the same message to two switches 30 through two or four redundant buses via two or four port network interface cards 20.

In FIG. 2 (b), since the first and second ports of the slave station 20 1 transmit and receive data to and from each switch 30 through the overlapped bus, one of the bus lines 1 and 2 occurs. Even if the message can be transmitted and received normally.

In the case of FIG. 2 (b), since the bus lines of the port 1 and the port 3 transmit and receive with one switch 30, the same message can be transmitted and received by the switch 20, so that the same message can be transmitted and received by the switch 20, which is higher than the network interface card of two ports. It can have fault-tolerant characteristics.

The application of the two switches 30 in the present invention is to safely process data even if a defect occurs in one switch 30 when relaying the communication between the master station 40 and the slave station 20.

That is, ports 1 and 2 of the slave station 20 1 transmit and receive data with other slave stations through 1 and 2 of the switch 30. Therefore, even if a failure occurs in either switch 1 or 2, the message transmitted from the station can be normally received.

In conclusion, in the multi-port network interface card, the redundant bus and the plurality of switches 30, and the multi-port network interface card proposed in the present invention, fault detection and failure of each element are generated through the network structure through the defect detection and output data determination algorithm. In addition, it is possible to safely maintain the network system for railway signal control facilities and secure a highly reliable network structure that can be easily restored.

Figure 3 shows an example of the configuration of a multi-port network interface card of the present invention.

Networking of the mentioned railway signal system of the present invention can simplify the complicated wiring scheme of the conventional point-to-point communication method, solve the maintenance problem and make it easy to expand.

Therefore, if the network of the railroad signal system is constructed using the switched Ethernet, which is made up of the shortcomings of the existing Ethernet, it is possible to achieve higher system performance than point-to-point communication.

3 is connected to the switch 24 by installing two ports using ATmega123L, which is used as the CPU 22 for Ethernet control, and the two RS232 ports 26 which are most widely used with the pre-installed railway signal equipments. It is a figure of NIC.

Most rail signaling systems now have an RS232 port 26 but no Ethernet port.

The present invention can be applied immediately without changing the system with existing railway signaling equipment by installing the RS232 port 26 provided in most railway signaling equipment as shown in FIG.

In addition, the multi-port network interface card of FIG. 3 may have four or more ports connected to the switch 24, and may be provided with a plurality of RS232 ports 26 to be combined with railway signal equipment.

The CPU 22 converts the serial data transmitted from the railway signaling equipment through the RS232 port into an Ethernet frame and outputs it to the Ethernet multiport, and converts the Ethernet frame received through the Ethernet multiport into serial data to change the RS232 port. It transmits to railway signal control facility and controls overall operation of network interface card.

As mentioned, the data processing operation of the railway signal system will be described with reference to FIGS. 1 to 3 of the present invention.

First, the master station 40 transmits data. The same data transmitted from the master station 40 is received in each of the different switches 30 installed in duplicate and provide the corresponding data to the network interface card 20 combined with a plurality of railway signal control equipment.

The plurality of network interface cards 20 respectively transmit the resultant transmission data from the connected railway signal control facilities to different switches 30 connected in duplicate. The redundant two switches 30 are provided with the respective received data to the master station 40 of the railway signal system.

In addition, the network interface card 20 compares the data received through the multiple ports to remove the fault data and output only normal data.

4 is an example of a connection diagram when real rail signaling equipment is interfaced using a multi-port network interface card and a switch and a dual communication bus proposed in the present invention.

In FIG. 4, two switches 20, a plurality of two-port network interface cards 30, and a railway signal facility 50 are connected, and the LDTS (railway signal facility 50 connected to the two-port network interface card 30) is connected to the switch. The following shows an example of connecting Local Data Transmission System), Maintenance Equipments, and Electronic Interlocking System (EIS) equipment.

One network interface card 30 transmits and receives the same data from the two switches 20, and provides and receives data to the connected railway signal facility 50 to build a stable network.

In addition, Figure 4 shows a railway signal control system using a network port card of two ports 30, but when building a railway signal control system using a network interface card of four ports to build a more stable and reliable network can do.

The network system for railway signal control equipment of the present invention uses a dual switch 20 and a network interface card 30 having multiple ports, and a failure in a switch or a network interface card input / output port or a transmission bus using a redundant multiple transmission bus. In case of occurrence, it is possible to process the operation stably in the railroad signal equipment, thus constructing a network system with highly reliable fault tolerance for railroad signals.

The present invention is not only easy to install and excellent in compatibility, but also has the effect of enabling real-time data processing, simplifying the wiring system and constructing a stable railway signal control network.

In addition, the present invention when the network of the railroad signal system using the switched Ethernet network to transmit and receive data redundantly, by applying a redundant bus structure, redundant switches to process the operation normally even if an error occurs in one device or data It is possible to provide a rail signaling system that enables the fault tolerance to secure stability and improve reliability.

So far, the configuration and operation of the embodiment of the present invention have been described. The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the technical idea of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments as well as the claims.

Claims (6)

A network interface card connected to a plurality of railway signal control facilities and having multiple input / output ports for transmitting and receiving identical data repeatedly through a plurality of input / output ports and transmitting and receiving only normal data in the data; A redundant switch connected to a network interface card to which the plurality of railway signal control facilities are connected to switch data using a buffer and to provide the data to the plurality of connected network interface cards; And a redundant bus for transmitting and receiving data between the network interface card and the switch. The method of claim 1, The network interface card may include two or four input / output ports connected to the switch; A plurality of RS232 ports for connecting to said plurality of railway signal control facilities; And a CPU for converting, processing, and controlling data transmitted and received from the input / output port and the RS232 port. The method of claim 1, The network interface card having the multiple ports is a network system for railroad signal control equipment using switched Ethernet, characterized in that for coupling a plurality of railroad signal control equipment through the redundant switch. In the network system for railway signal control equipment, Transmitting and receiving data from a multiple input / output port network interface card, determining received data, removing fault data, and outputting only normal data; Receive data transmitted from any railway signal control facility with network interface card in different overlapping switches, and provide the data to network signal card connected to other railway signal control facility. Signal processing method of network system for railway signal control equipment using switched Ethernet, characterized in that the process includes The method of claim 4, wherein The multi-input / output port network interface card has an RS232 port to be combined with the railway signal control facility, and converts serial transmission data from the railway signal control facility through the RS232 port into an Ethernet frame and outputs it to an Ethernet multiport port. Signal processing method of a network system for railway signal control equipment using switched Ethernet, characterized by converting the Ethernet frame inputted through multiple Ethernet ports into serial data and transmitting it to the railway signal control equipment through the RS 232 port. The method of claim 4, wherein The signal processing method of the network signal control equipment network system using a switched Ethernet, characterized in that the network system for the railway signal control equipment to install a redundant communication bus to process data.

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