JP7202255B2 - Communications system - Google Patents

Description

TECHNICAL FIELD The present invention relates to communication systems, and is particularly suitable as a communication system for railway operations using multiplexed networks.

The connection method of the communication system used in the railway business is required to have at least high immediacy and redundancy for reasons such as continuity of train operation, responsiveness of passenger information, and availability of management of electric power, signals, etc. In this respect, it is preferable to employ a multiple network system.

FIG. 3 is a diagram showing an example of the configuration of a conventional communication system used in railway business, and has a connection configuration corresponding to a multiplex network system.

A network (NW) (hereinafter sometimes referred to as “NW”) connects the central command center 1 to each station (for example, a station 2) and a railway substation (for example, b substation 3) A multiplexed NW (redundant configuration of NW1 system to NWn system; n is an integer of 2 or more; however, in FIGS. 3 and 4, n is 2). Here, each separated NW topology may be either a ring-type configuration, a bus-type configuration or a star-type configuration.

The central command center 1 includes one or more central processing units (two central processing units 11 and 12 in FIG. 3 as an example) for operating various systems related to railway operation, and 1 operated by a dispatcher or the like. More than one operation terminal (one operation terminal 13 in FIG. 3 as an example) is provided.

Station a 2 includes one or more input/output devices A (in FIG. 3, input/output device A21 as an example) connected to various external devices installed at the station. The b substation 3 includes one or more input/output devices B (in FIG. 3, the input/output device B31 as an example) connected to various external devices installed in the railway substation. Both the input/output device A and the input/output device B are devices that can be called terminals when viewed from the central command center 1 .

Each device provided in the central command center 1, a station 2, and b substation 3 emphasizes the immediacy of monitoring and control, and in order to transmit and receive information between one-to-n devices, communication protocols UDP/IP Communication is performed using a directed broadcast address of (User Datagram Protocol/Internet Protocol).

As a transmission method between devices, each broadcast frame transmitted by each device is given a serial number version (device activation time) and a serial number. When transmitting information, each device transmits the same information with the same serial number assigned to all multiplexed NWs. Then, the device that receives this broadcast frame compares it with the previously received frame, and discards the later-arriving frame if the serial number version and serial number are the same.

The central processing units X11 and Y12 are equipped with a plurality of network interfaces, are connected to each of the multiplexed NWs (NW1 system to NWn system), and use the above transmission method to transmit control information and information related to external device status. receive. Specifically, from the input/output device A21 and the input/output device B31 installed at each station (a station 2) and the electric railway substation (b substation 3), various information such as on-track information, failure information, circuit breaker information, etc. Received via multiplexed NW (NW1 system to NWn system). In addition, based on the received information, control information is sent to the multiplexed NW (NW1 system to NWn system) in order to control train operations, edit passenger guidance information, monitor equipment failures, control circuit breakers, etc. do.

The input/output devices A21 and B31 are equipped with a plurality of network interfaces, are connected to each of the multiplexed NWs (NW1 system to NWn system), and use the above transmission method to transmit information acquired from external devices and control information. Receives and outputs control to external devices. Specifically, it is installed at each station (a station 2) and electric railway substation (b substation 3), takes in information such as on-line information, failure information, circuit breaker information, etc. from external equipment, and multiplexes NW (NW1 series to NWn system) to Central Command Center 1. It also outputs control information received from the central processing units X11 and Y12 and the operation terminal 13 via the multiplexed NW (NW1 system to NWn system) to an external device.

The operation terminal 13 is equipped with a plurality of network interfaces and is connected to each of the multiplexed NWs (NW1 system to NWn system). Receive status information and display the status. Specifically, various types of information such as on-track information, failure information, circuit breaker information, etc. are multiplexed from the input/output devices A21 and B31 installed at each station (a station 2) and electric railway substation (b substation 3) NW ( NW1 system to NWn system) and displays the status. In addition, based on the manual input information of the dispatcher or the like, control information is transmitted to the multiplexed NW (NW1 system to NWn system) in order to control the operation of trains, control circuit breakers, and the like.

On the other hand, some input/output devices such as signal equipment and power equipment used in stations and substations for electric railways, and input/output devices related to passenger services, etc., do not support multiple systems, but single Many have network interfaces.

FIG. 4 is a diagram showing another example of the configuration of a conventional communication system used in railway business. Even in a multiplexed NW, input/output devices have a single network interface.

The configuration of the central processing units X11 and Y12 and the operation terminal 12 provided in the central command center 1 and the connection mode to the network (NW1 system to NWn system) are the same as the configuration example shown in FIG. 3, so description thereof will be omitted.

The input/output device C22 installed at station a 2 and the input/output device D32 installed at substation b 3 have a single network interface and are connected to any one of multiplexed NWs (NW1 system to NWn system). Then, using the above transmission method, the external device status is transmitted and control information is received.

Further, in Patent Document 1, as an information transmission system mounted on a railway vehicle, when duplicated transmission lines are configured by IP subnets different from each other, from a packet including an identifier indicating a destination transmission line system , a technique of generating a plurality of packets having a destination identifier corresponding to each system and transmitting the generated plurality of packets to a transmission line of the system corresponding to the identifier.

JP 2012-105164 A

In order to make the transmission line redundant, in the method shown in FIG. An output device needs to be equipped with multiple network interfaces. Furthermore, the broadcast frame to be communicated also has the aspect of reaching all devices connected to the same network (NW).

In addition, in the method of connecting input/output devices having a single network interface as shown in FIG. 4, the input/output device is connected to only one NW, so multiplexed NWs cannot be used effectively. . Furthermore, in the case where the NW has a bus-type configuration or a star-type configuration, if a disconnection occurs in the NW of the system to which the input/output devices are connected, it becomes impossible to transmit and receive information. ), it takes a long time to change the topology, resulting in loss of information to be transmitted and received.

Furthermore, the technique described in Patent Document 1 relates to a redundant network in a railway vehicle, and is not intended for a ground-side network system used in railway business.

In order to solve the above problems, the present invention connects a repeater between an input/output device having a single network interface and a multiplexed NW, thereby utilizing the multiplexed NW even if the path is disconnected or To enable data transmission/reception without loss by using a remaining route (NW) even when a momentary interruption occurs due to route switching.

A communication system according to the present invention includes a multiplexed network of two or more layers connecting a central processing unit and a first terminal, a second terminal having a single network interface, a multiplexed network and the second terminal. The second terminal communicates to the multicast router the same number of reception request information as the multiplexing degree of the multiplexed network to enable simultaneous use of the multiplexed network, and the multicast router connects receiving and analyzing incoming request information from the central processing unit or first terminal via the network, and replicating and forwarding outgoing information from the second terminal to respective networks of the multiplexed network; Characterized by

According to the present invention, even an input/output device having a single network interface can be incorporated into a multiplexed network system. It is possible to improve the reliability of two-way information arrival with.

It is a figure which shows an example of the structure of the communication system which concerns on the Example of this invention, and added the flow of information in the case of transmitting transmission information from an input-output device. 1 is a diagram showing an example of a configuration of a communication system according to an embodiment of the present invention, and adding an information flow when an input/output device receives control information; FIG. It is a figure which shows an example of a structure of the conventional communication system used for a railway business. FIG. 2 is a diagram showing another example of the configuration of a conventional communication system used in railway business;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, as a mode for carrying out the present invention, examples will be described with reference to the drawings.

1 and 2 are diagrams showing an example of the configuration of a communication system according to an embodiment of the present invention.
The central command center 1, a station 2, b substation 3, each of the constituent devices (central processing unit, operation terminal and input/output device C and D) and multiplexed NW (NW1 system to NWn system) are the above It is the same as that explained in FIG. 4 (the multiplexed NW is exemplified with n being 2).
Also, FIG. 1 shows the flow of information when transmission information is transmitted from the input/output device, and FIG. 2 shows the flow of information when the input/output device receives control information.

In the present invention, each device connected to a multiplexed NW (NW1 system to NWn system) emphasizes immediacy of monitoring and control, and transmits and receives information between one-to-n devices. Communication is performed using an IP multicast address. Multicast is abbreviated as "MC". Also, when viewed from the central command center 1, the input/output devices C and D, which correspond to terminals, have a single network interface.

In the MC frame when each device transmits information, the TTL (Time to Live) in the IP header is set to the number of MC routers that are transit relays+1. Note that the MC router will be described later.

In addition, a serial number version (for example, device startup time) and a serial number are given to each MC frame, which is a transfer unit when each device transmits information. As a result, when each device transmits information, the same information with the same serial number is transmitted to all multiplexed NWs (NW1 system to NWn system). Then, the device that receives the MC frame discards the later-arriving frame if the serial number version and serial number are the same as those of the previously received frame.

An MC router (a station 2 and the MC router F33 installed at b substation 3) are connected.

The MC routers (MC router E23 and MC router F33) connect input/output devices (input/output device C22 and input/output device D32) and multiplexed NWs (NW1 system to NWn system), and each connected port is a virtual local The network is divided by area network (VLAN). At that time, when the MC routers (MC router E23 and MC router F33) receive an MC address request (IGMP (Internet Group Management Protocol) membership report) as shown on the right side of FIGS. 1 and 2, the MC routing function routes the frame with the requested MC address to the requested port.

The multiplexed NW (NW1 system to NWn system) operates an IGMP snooping function to transfer the MC frame only to the port of the device that transmitted the MC address request (IGMP membership report).

For the input/output device C22 and the input/output device D32, one MC address to be transmitted is defined for each input/output device. Also, the MC addresses received by each input/output device are defined for the number of multiplexed NWs. As a result, multiplexed NWs (system NW1 to system NWn) can be used simultaneously for communication in the reception direction by communicating with the defined number of multiplexed NWs. An example of setting the transmission MC address and the reception MC address is shown below.

For the input/output device C22,
- Transmission MC address: 239.1.0.1
・Receive MC address 1: 239.1.1.1 to receive MC address n: 239.1. n. 1

For the input/output device D32,
- Transmission MC address: 239.2.0.1
・Receiving MC address 1: 239.2.1.1 to receiving MC address n: 239.2. n. 1

Next, the flow of MC address requests and MC frames between central processing unit X11, central processing unit Y12, operation terminal 13 and input/output device C22 and input/output device D32 will be described.

Based on the MC address request (MC address: 239.1.1.1) from the central processing unit X11, the central processing unit Y12, or the operation terminal 13, from the corresponding input/output unit C22, information of serial number α as transmission information is sent to the central control center 1 through the NW1 system and the NWn system by routing by the MC router E23 (flow shown on the right side of FIG. 1).

Also, in response to an MC address request (MC address: 239.2.1.1 and MC address: 239.2.n.1) from the input/output device D32, the MC router F33 sends a central It receives the control information with the serial number β from the command center 1 (for example, the operation terminal 13) and sends it to the input/output device D32. In the input/output device D32, among the received control information with the serial number β, the MC address: 239.2. n. The control information that arrives after 1 is discarded (the flow shown on the right side of FIG. 2).

As described above, even with a device having a single network interface, by using a repeater (MC router), the redundancy of the multiplexed NW is utilized, and even if there is an instantaneous interruption due to path disconnection or path switching, Data can be transmitted and received without loss using the remaining path (NW). Thereby, the reliability of information arrival can be improved. In addition, since the MC frame does not reach a device that does not transmit the MC address request (a device that does not need to receive the MC frame), the load on the device can be reduced.

1... central command center, 11... central processing unit X, 12... central processing unit Y, 13... operation terminal,
2... a station, 21... input/output device A, 22... input/output device C, 23... MC router E,
3...b substation (electric railway substation), 31...input/output device B, 32...input/output device D,
33 MC router F

Claims (2)

a two or more multiplexing network connecting the central processing unit and the first terminal;
a second terminal having a single network interface;
A multicast router that connects the multiplexed network and the second terminal ,
The second terminal communicates the same number of reception request information as the multiplexing degree of the multiplexed network to the multicast router to enable simultaneous use of the multiplexed network;
The multicast router receives and analyzes reception request information from the central processing unit or the first terminal via the multiplexed network, and transmits information transmitted from the second terminal to each of the multiplexed networks. A communication system characterized by duplicating and transferring to a network of A communication system according to claim 1,
A central command center having the central processing unit and the first terminal,
The second terminal is provided in at least one of a station and a railway substation
A communication system characterized by:

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