JP6162996B2 - Network control apparatus and method - Google Patents

Description

  The present invention relates to a network control apparatus and method in a duplex network system.

  The network is configured by connecting a plurality of network control devices so that they can communicate with each other. Each device has address information and performs communication using the address information. Therefore, this address information needs to be unique within the network.

  However, in practice, address information may be duplicated among a plurality of network control devices constituting the network. For example, when address information such as an IP (Internet Protocol) address or a station address (manually set in each network control device as an address for each device, hereinafter referred to as an ST address) is used, the address information due to human error. May be set redundantly, and addresses may be duplicated among a plurality of network control devices. Methods for detecting duplication of address information between network control devices are described in, for example, Japanese Patent Application Laid-Open Nos. 2009-010459 and 2001-244945.

JP 2009-010459 A JP 2001-244945 A

  If duplication of address information is detected among multiple network control devices that make up the network, one of the network control devices with duplicate address information is blocked from the network in order to prevent malfunctions throughout the network. To do.

  When a duplex network system is constructed, the network system is constructed by two networks A and B, and each computer is connected so as to have a network control device for the network A system and a network control device for the network B system. The network A system and the network B system do not have a network controller connected in common, and the network controller of each computer is the same for the network controller for the network A system and the network controller for the network B system. The ST address (computer identifier) is set.

  In the above network system, when the A system network control device of one computer and the B system network control device of the other computer are connected due to a wiring error or the like, each device has the same ST address in the same network. There is a problem that more than half of the network control devices in the network system are disconnected from the network.

  An object of the present invention is to provide a large number of network control devices from the network system even if the network A system control device of one computer and the network B system control device of the other computer are connected in the network system. It is an object of the present invention to provide a network control method and a network system that do not block the network.

  In order to achieve the above object, according to the present invention, each network control device has an ST address (computer identifier, local ID) and an IP address (network identifier, global ID) as address information. The IP address of the control device is configured to have a means for determining whether it is a network control device set for the A-system or B-system network and a means for detecting duplication of the ST address of each network control device.

  More specifically, a common value (A) is set in the network address part of the IP address for the A-system network control device, and a common value (B) in the network address part of the IP address is set for the B-system network control device. When each network controller receives data from another network controller, the network address part of the IP address of the source network controller that sent the data and the network control of the recipient that received the data The network address part of the IP address of the device is compared, and if they do not match, the received data is discarded, and communication between the A system network control device and the B system network control device is cut off. The network controller and the B system network controller are connected to the same network. The to prevent. In addition, by comparing the IP addresses before detecting duplication of ST addresses, it is possible to prevent a large number of network control devices from being blocked from the network system due to duplication of ST addresses.

  According to the present invention, in a network system constructed so as to have two networks A system and B system, and each computer has a network control apparatus for network A system and a network control apparatus for network B system, Even if the same ST address is set in the network control device and the network B network control device, and the network A system control device of one computer is connected to the network B system control device of the other computer, the ST Based on the address, it is possible to prevent the network control apparatus from being disconnected from the network system.

It is the figure which showed the outline | summary of the network system. It is a processing flow figure of a network control apparatus. It is the figure which showed the structure at the time of connecting the apparatus 6, 7, 8, 9, 10, 11 to the same ring type network in a network system. FIG. 4 is a diagram showing a state in which communication between the computer 1 (3) and the computer 2 (4) is blocked in the configuration shown in FIG.

  FIG. 1 is a block diagram showing an outline of a network system for carrying out the present invention.

  Each of the computers 3, 4, and 5 has two network control devices for the A system and the B system. Each of the network control devices 6, 7, 8, 9, 10, 11 has an ST address (computer identifier, local ID) and an IP address (network identifier, global ID) as address information. The ST addresses of the network control devices 6 and 7 are set to 1, the ST addresses of the network control devices 8 and 9 are set to 2, and the ST addresses of the network control devices 10 and 11 are set to 3. The network address part of the IP addresses of the network control devices 6, 8, 10 is set to A, and the network part of the IP address of the network control devices 7, 9, 11 is set to B. The network control devices 6, 8, and 10 are connected to each other through physically different transmission paths to form a ring network 1 (network A system). The network control devices 7, 9, and 11 are connected by physically different transmission paths to form a ring network 2 (network B system).

  When the network control device 6, 7, 8, 9, 10, 11 transmits data to another network control device, or another network control in which data received from another network control device is directly connected via a transmission path When relaying and transmitting to a device (hereinafter referred to as an adjacent network control device), a frame including the IP address of the transmitting network control device is transmitted.

Processing in the network control apparatus will be described with reference to FIG.
When the network control devices 6, 7, 8, 9, 10, 11 receive data from adjacent network control devices, the network control device refers to the network address part of the IP address of the transmitting network control device from the received frame. It is determined whether the network address part of the IP address possessed by the transmission side network control apparatus matches the network address part of the IP address possessed by the reception side network control apparatus (201). The received frame is discarded, a warning is issued via the display (LED, etc.) (203), the network address part of the IP address is mismatched, communication with the adjacent network control device is interrupted (204), and communication is interrupted The received data (received frame) from the network control apparatus is discarded (205). If the network address part of the IP address possessed by the transmission side network control device matches the network address part of the IP address possessed by the reception side network control device, duplication detection of the ST address is performed (202).

  As shown in FIG. 2, by comparing the IP addresses before detecting the duplication of the ST address, the local network failure due to the duplication of the ST address occurring in a specific network control apparatus can be performed. This prevents a large number of network control devices from being blocked from the system.

  FIG. 3 shows a configuration when the network control devices 6, 7, 8, 9, 10, and 11 join the same ring network due to a transmission path connection error. When the network control device 6 receives data from the network control device 9 according to FIG. 2, the network address part B of the IP address of the network control device 9 and the network address part A of the IP address of the network control device 6 do not match. The received data from the network control device 9 is discarded.

  Similarly, the network control device 7 discards the received data from the network control device 8, the network control device 8 discards the received data from the network control device 7, and the network control device 9 receives the received data from the network control device 6. Is discarded. As a result, communication is cut off only between the network control device 6 and the network control device 9 and between the network control device 7 and the network control device 8, and the A system network control device and the B system network control device are connected to the same network. Prevent the connection.

  In FIG. 3, communication between the network control device 6 and the network control device 9 and between the network control device 7 and the network control device 8 is interrupted, that is, between the computer 3 and the computer 4. FIG. 4 shows a state where communication is interrupted. A broken line in FIG. 4 indicates a connection that interrupts communication.

  The present embodiment described above can be applied to duplicate detection of address information of a network control device in a communication network that interconnects a plurality of devices that monitor or control the operation of a plant.

1, 2: Network, 3-5: Computer, 6-11: Network control device

Claims (6)

A plurality of computers are connected in a ring shape by a first system network and a second system network, and the computer is a network system having network control devices corresponding to the first system and the second system. There,
The network control device has a unique ST address for identifying the computer and an IP address part for identifying the network,
Self network controller receives the data from the adjacent network controller refers to the IP address portion and ST address portion of the IP address portion and ST address and self network controller of the network controller for said adjacent received, the neighbor It checks whether the network address part of the IP address of the network controller to be inconsistent with the network address part of the IP address of the self network controller , and then the ST address and the self network controller of the adjacent network controller A network control device characterized by checking whether or not the ST address of the device does not match, and discarding the received frame when detecting a mismatch of the network address part of the IP address . The network address parts of the IP addresses are compared with each other between adjacent network control devices, and when the network address parts of the IP addresses do not match, the display unit detects and displays the mismatch of the network address part of the IP address. The network control device according to claim 1. The network address units of the IP addresses are compared with each other between adjacent network control devices, and the self-network control device that detects a mismatch of the network address portions of the IP addresses blocks communication with the adjacent network control device. The network control device according to claim 1. In a network system in which a plurality of computers are connected in a ring shape by a first system network and a second system network, a network control apparatus corresponding to the first system and the second system possessed by the computer A network control method according to
The network control device holds a unique ST address for identifying the computer and an IP address part for identifying the network,
The self network control device that has received data from the adjacent network control device refers to the received IP address portion and ST address of the adjacent network control device and the IP address portion and ST address of the self network control device ,
The self network controller refers to the adjacent when receiving data from the network controller, the IP address portion and ST address of the IP address portion and ST address and self network controller of the network controller for said adjacent received,
The network control method, wherein the self-network control device discards a received frame when detecting a mismatch of a network address part of the IP address . The network address parts of the IP addresses are compared with each other between adjacent network control devices, and when the network address parts of the IP addresses do not match, the display unit detects and displays the mismatch of the network address part of the IP address. The network control method according to claim 4, wherein: The network address units of the IP addresses are compared with each other between adjacent network control devices, and the self-network control device that detects a mismatch of the network address portions of the IP addresses blocks communication with the adjacent network control device. The network control method according to claim 4, wherein:

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