Location information relay device, location information acquisition system, location information relay method, and program

Abstract

A position information relay device (31) between a network device and an apparatus comprises: a position information tracking unit (311) that tracks position information of the apparatus; and a position information relay unit (312) that receives a communication packet transmitted to the network device by the apparatus, includes the position information in the received communication packet, and transmits the communication packet having the position information included therein to the network device.

Description

[Technical Field]

[0001] The present invention relates to a location information relaying device, a location information acquisition system, a location information relaying method, and a program. [Background technology]

[0002] There is a technology that can automatically acquire location information of terminals connected to a network (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-318432 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology disclosed in Patent Document 1 cannot be applied to switching hubs that do not support SNMP, which poses a problem in that the technology disclosed in Patent Document 1 cannot be added to an already installed network.

[0005] Therefore, the present invention provides a location information relay device or the like that contributes to grasping the location information of connected devices. [Means for solving the problem]

[0006] A location information relay device according to one embodiment of the present invention is a location information relay device that is interposed between a network device and an appliance, and is equipped with a grasping unit that grasps the location information of the appliance, and a relay unit that receives communication packets sent by the appliance to the network device, includes the location information in the received communication packets, and transmits the communication packets with the location information included to the network device.

[0007] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, or may be realized as any combination of a system, a method, an integrated circuit, a computer program, and a recording medium. [Effects of the Invention]

[0008] The location information relay device of the present invention contributes to grasping the location information of the connected device. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a location information acquisition system according to an embodiment. [Figure 2] FIG. 2 is a diagram showing address information of devices according to the embodiment. [Figure 3] FIG. 3 is a configuration diagram of a location information acquisition terminal according to an embodiment. [Figure 4] FIG. 4 is a diagram showing an example of a position information list according to the embodiment. [Figure 5] FIG. 5 is a configuration diagram of a location information relay device according to an embodiment. [Figure 6] FIG. 6 is a diagram showing an example of a position information conversion list according to the embodiment. [Figure 7] FIG. 7 is a sequence diagram of the location information acquisition system according to the embodiment. [Figure 8] FIG. 8 is a diagram illustrating a packet format of an ARP request according to the embodiment. [Figure 9] FIG. 9 illustrates a packet format of an ARP response according to the embodiment. [Figure 10] FIG. 10 is a flowchart of the location information acquisition process according to the embodiment. [Figure 11] FIG. 11 is a diagram illustrating an example of a location information acquisition request packet according to the embodiment. [Figure 12]FIG. 12 is a diagram illustrating an example of a location information acquisition response packet according to the embodiment. [Figure 13] FIG. 13 is a flowchart of the location information grasping process according to the embodiment. [Figure 14] FIG. 14 is a flowchart of the location information acquisition request transfer process according to the embodiment. [Figure 15] FIG. 15 is a flowchart of the location information acquisition response transfer process according to the embodiment. [Figure 16] FIG. 16 is a diagram showing a sequence example (1) of the location information system according to the embodiment. [Figure 17] FIG. 17 is a diagram showing a sequence example (2) of the location information system according to the embodiment. [Figure 18] FIG. 18 is a diagram showing a sequence example (3) of the location information system according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Findings that form the basis of the present invention) The present inventors have found that the techniques described in the "Background Art" section have the following problems.

[0011] In recent years, the movement towards smart factories has become more active both domestically and internationally, and devices and equipment within factories are now being connected to networks.

[0012] Traditional factory networks were basically isolated from the Internet or the company's internal LAN (Local Area Network) and had a closed network configuration.

[0013] However, in recent years, operational data from equipment within factories is often collected in the cloud to visualize operating status and be used for early detection of problems or performance management of the entire factory, and there is an increasing number of configurations in which equipment or devices within factories are connected to the company's internal LAN or the Internet.

[0014] As a result, equipment or devices within factories can become targets of cyber attacks, and there have been many cases of cyber attacks targeting factory networks.

[0015] While it is possible to install virus detection software to ensure security for IT (Information Technology) devices such as office PCs (Personal Computers), availability is of paramount importance for factory equipment, making it difficult to implement measures such as installing virus detection software, applying patches regularly, or updating the OS (Operating System), which could potentially cause system outages.

[0016] Therefore, it is important to take measures to strengthen cyber resilience for factory equipment, while assuming that it is in a vulnerable state. One such measure is a solution that monitors communication traffic flowing through the factory network in real time and detects abnormalities in factory equipment caused by unauthorized access, virus infection, etc. When an abnormality is detected, the above solution makes it possible to minimize damage by taking measures such as quickly cutting off communication with the relevant device.

[0017] Typically, network addresses such as IP (Internet Protocol) addresses or MAC (Media Access Control) addresses are used as identifiers to identify devices in which an abnormality has occurred. However, if it is not immediately possible to determine which device in the factory the network address is linked to, there is a risk that the response will be delayed and the damage will be greater.

[0018] Therefore, in order to respond quickly to abnormalities in equipment within a factory, it is important to link and manage the equipment's network address with its physical location, but the reality is that there are many factories where this management is not done properly.

[0019] Furthermore, when configuring a new factory network, a list linking devices to their physical locations may be created and managed. However, if new devices are added after the list is created, or if the location of devices is changed due to line changes or other reasons, updates may be missed, and when the physical location of a device needs to be known, the physical location of that device may not be known, making it impossible to take action.

[0020] As such, it is not easy to manually manage the physical location information of equipment within a factory over many years.

[0021] There is a technology that can automatically obtain location information of terminals connected to a network (see Patent Document 1). In this technology, a table that associates ports of a switching hub with location information of the switching hub, access point, or terminal device connected to that port is prepared in advance in a location information management server. Then, using SNMP (Simple Network Management Protocol), the upstream switching hub sequentially reads routing information including the port and the MAC address of the device connected to that port toward the downstream switching hub, and sequentially tracks the devices connected to each port and compares them with the table to determine the current location of the terminal device.

[0022] The technology described in Patent Document 1 makes it possible to automatically obtain location information of terminal devices using a network protocol. In addition, location information can be obtained by tracking not only wired connected devices but also wirelessly connected devices when they move, so it is possible to continue obtaining location information of terminal devices even if the location of the device changes due to changes in factory lines, etc.

[0023] However, the technology disclosed in Patent Document 1 requires that the switching hub is compatible with SNMP; in other words, it cannot be applied to a switching hub that does not support SNMP.

[0024] Currently, there are very few commercially available switching hubs that support SNMP. Furthermore, if a factory network is already configured with a switching hub that does not support SNMP, it will need to be replaced with an SNMP-compatible switching hub, which is difficult to implement because it would stop the factory network.

[0025] Therefore, the technology disclosed in Patent Document 1 has a problem in that it may not be possible to add it to a network that has already been installed.

[0026] Furthermore, the location information management server must have a table prepared in advance that links the ports of the switching hub with the location information of the switching hubs or access points and terminal devices connected to them, but consistency is lost when the switching hub is moved due to a line change, etc. Therefore, unless the information in the table is updated through regular maintenance of the location information management server, it will not contribute to the accurate identification of location information.

[0027] The present invention provides a location information relay device or the like that contributes to appropriate understanding of location information of connected devices.

[0028] In order to achieve the above-mentioned object, a location information relay device according to one embodiment of the present invention is a location information relay device that is interposed between a network device and an equipment, and that is equipped with a grasping unit that grasps the location information of the equipment, and a relay unit that receives communication packets that the equipment has sent to the network device, includes the location information in the received communication packets, and transmits the communication packets with the location information included to the network device.

[0029] According to the above aspect, the location information relay device transmits the location information of the device contained in a communication packet sent from the device to a network device. This allows the device's location information to be transmitted using existing network devices and existing devices. If a new network protocol is introduced or new software needs to be installed on a device when a location information relay device is installed, availability may be reduced due to network outages caused by changing the network device's or device's settings or adding new functions, or due to behavioral changes that occur as a result of the introduction. Since the location information relay device according to one aspect of the present invention does not require changes to existing network devices or existing devices, it contributes to preventing such a decrease in availability. Furthermore, it can be smoothly applied to existing networks. Furthermore, accurate location information can be transmitted each time without requiring regular maintenance on existing network devices and existing devices. In this way, the location information relay device contributes to the detection of location information of connected devices.

[0030] For example, the location information relay device may be installed within a predetermined distance from the equipment, and the grasping unit may have a sensor that acquires location information of the location information relay device, and the location information of the location information relay device acquired by the sensor may be grasped as location information of the equipment.

[0031] According to the above aspect, the location information relay device can easily grasp the location information of the device using the sensor. Therefore, the location information relay device contributes to more easily grasping the location information of the connected device.

[0032] For example, the relay unit may identify a command of a network protocol used in the received communication packet, determine whether the command of the identified network protocol is a predetermined command, and if it determines that the command of the identified network protocol is the predetermined command, include the location information in a predetermined field included in the communication packet.

[0033] According to the above aspect, the location information relay device includes location information in a predetermined field of a communication packet of a predetermined command of a network protocol sent from a device to a network device, eliminating the need to add a dedicated network protocol for transmitting location information. If a dedicated network protocol were required, it would require configuration changes or additional functions to the network device or device, which could result in reduced availability. Since the location information relay device according to one aspect of the present invention does not require the addition of a dedicated network protocol, it contributes to preventing the above-mentioned reduction in availability. In this way, the location information relay device further contributes to understanding the location information of connected devices.

[0034] For example, the device may be connected to a management device via one or more of the network devices, and the management device may send a request packet including a request command defined by a network protocol to the device, and the relay unit may receive the request packet and send it to the device, and receive as the communication packet a response packet that the device sent to the management device in response to the request packet, the response packet including the response command defined by the network protocol.

[0035] According to the above aspect, the location information relay device transmits a response packet containing the device's location information in response to a request packet transmitted by the management device. This allows the timing of transmitting the device's location information to be determined based on control by the management device. By transmitting the location information at a more appropriate timing, the location information relay device contributes to understanding the location information of the connected device.

[0036] For example, when the relay unit receives the request packet, it may determine whether a predetermined code is included in a predetermined field in the received request packet, and if it determines that the received request packet contains the predetermined code, it may receive the response packet as the communication packet, with the device set as the destination of the received request packet as the sender, include the location information in the received communication packet, and transmit the communication packet with the location information included to the network device.

[0037] According to the above aspect, upon receiving a request packet containing a predetermined code, the location information relay device transmits a response packet subsequently sent by the device addressed to the request packet, including the device's location information. The predetermined code can be set by the management device. This allows the device whose location information is to be known to be determined based on the setting by the management device. Therefore, the location information relay device contributes to the knowledge of the location information of the connected device under the control of the management device.

[0038] For example, the grasping unit may be a transmitter that receives a signal that includes information specific to the location where the transmitter is installed, and grasps the location information of the device from the received signal.

[0039] According to the above aspect, the location information relay device receives a signal transmitted by a transmitter and easily ascertains the location information of the device. Therefore, the location information relay device more easily contributes to appropriate ascertainment of the location information of the connected device.

[0040] For example, the location information relay device may further include a storage unit that stores the location information grasped by the grasping unit.

[0041] According to the above aspect, the location information relay device can store the location information of the device, eliminating the need to obtain the location information of the device each time, and thus enabling the location information of the device to be obtained efficiently. Therefore, the location information relay device contributes to appropriate and efficient obtaining of the location information of the connected device.

[0042] For example, the network protocol may be ARP (Address Resolution Protocol).

[0043] According to the above aspect, the location information relay device can transmit device location information using ARP packets. Since all existing devices connected to the network can communicate using ARP, the location information relay device can transmit device location information without the need to introduce a new network protocol communication function. Therefore, the location information relay device contributes to understanding the location information of connected devices.

[0044] In order to achieve the above-mentioned object, a location information acquisition system according to one embodiment of the present invention is a location information acquisition system comprising a network device, an appliance, a management device connected to the appliance via the network device, and the above-mentioned location information relay device interposed between the network device and the appliance.

[0045] According to the above aspect, the same effects as those of the above location information relay device can be achieved.

[0046] For example, the management device may send a request packet including request information, which is information requesting location information of the device, to the device; the relay unit may receive the request packet sent by the management device and send it to the device; the device may receive the request packet and send a response packet to the management device in response to the request packet; the relay unit may receive the response packet sent by the device as the communication packet and include the location information in the received response packet and send it to the management device.

[0047] According to the above aspect, the location information acquisition system transmits a response packet from a device in response to a request packet transmitted by the management device, the response packet including the device's location information. This allows the location information acquisition system to determine the timing of transmitting the device's location information based on control by the management device. By transmitting the location information at more appropriate timing, the location information acquisition system contributes to understanding the location information of connected devices.

[0048] For example, the management device may include a storage unit that stores the IP address, MAC address, and location information of the device in association with each other.

[0049] According to the above aspect, the location information acquisition system can appropriately manage the IP address, MAC address, and location information of a device. For example, when a cyberattack or malware infection of a device is detected, the system can provide the administrator with the physical location information of the device based on the IP address of the device, thereby contributing to a rapid response to the cyberattack, etc. Therefore, the location information acquisition system contributes to a rapid response to the cyberattack, etc., by grasping the location information of connected devices.

[0050] For example, the location information acquisition system may further include a transmitter that emits a signal containing information specific to the location where the transmitter is installed, and the transmitter may be installed within a facility.

[0051] According to the above aspect, the location information acquisition system further contributes to grasping the location information of the device by using the signal transmitted by the transmitter installed in the facility.

[0052] For example, the location information acquisition system may further include a transmitter that emits a signal containing information specific to the location where the transmitter is installed, and the transmitter may be installed outside the facility.

[0053] According to the above aspect, the location information acquisition system further contributes to grasping the location information of the device by using a signal transmitted by a transmitter installed outside the facility.

[0054] In order to achieve the above-mentioned object, a location information relay method according to one embodiment of the present invention is a location information relay method executed by a location information relay device interposed between a network device and a device, which grasps the location information of the device, receives a communication packet sent by the device to the network device, includes the location information in the received communication packet, and sends the communication packet with the location information included to the network device.

[0055] According to the above aspect, the same effects as those of the above location information relay device can be achieved.

[0056] In order to achieve the above object, a program according to one aspect of the present invention is a program that causes a computer to execute the above location information relay method.

[0057] According to the above aspect, the same effects as those of the above location information relay device can be achieved.

[0058] These comprehensive or specific aspects may be realized as a system, a method, an integrated circuit, a computer program, or a recording medium such as a computer-readable CD-ROM, or as any combination of a system, a method, an integrated circuit, a computer program, or a recording medium.

[0059] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0060] The embodiments described below are all comprehensive or specific examples. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present invention. Furthermore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components.

[0061] (Embodiment) In this embodiment, a location information relay device that contributes to grasping location information of connected devices will be described.

[0062] A location information relay device is introduced into an existing network (for example, a factory network) and contributes to the accurate understanding of the location information of connected devices. When introducing a location information relay device, there is no need to replace network devices such as routers or switching hubs that make up the existing network. Therefore, the location information relay device can be introduced without stopping the factory network that is already in operation.

[0063] Furthermore, when introducing a location information relay device, there is no need to install a program on the device. The location information relay device is attached to the outside of the device, and it grasps the device's physical location information on behalf of the device and transmits it to the location information management terminal. In this way, the location information relay device can minimize its impact on the operation of the existing network.

[0064] [1. Details of the embodiment] A location information acquisition system according to this embodiment will be described with reference to the drawings. In this embodiment, for example, lighting equipment in a factory stores physical location information data in advance. Then, a location information relay device (e.g., a dongle) connected to the factory equipment extracts the physical location information of the equipment from the received illumination light and transmits the location information to a location information acquisition terminal (e.g., a tablet). In this way, the location information acquisition terminal acquires the physical location of the equipment in the factory.

[0065] [1.1 Overall configuration of location information acquisition system] 1 is a diagram showing the network configuration of a location information acquisition system within a factory. The location information acquisition system is configured with a factory network 10, location information acquisition terminal 20, location information relays 31, 32, and 33, devices 41, 42, 43, and 44, and location information transmitters 51, 52, 53, and 54. Note that factory network 10 and devices 41, 42, 43, and 44 do not necessarily have to be components of the location information acquisition system.

[0066] As an example, the factory is a single-story building divided into four areas: Block A of Zone 1, Block B of Zone 1, Block A of Zone 2, and Block B of Zone 2. Note that the factory is not limited to this area division, and may be a two-story building, or may be divided into areas other than four.

[0067] The factory network 10 is a commonly configured LAN, and is configured with one or more network devices such as commercially available routers or switching hubs. The devices 41, 42, 43, and 44 are generally configured to be connected to the factory network 10 by Ethernet (registered trademark) cables, but may also be connected by other transmission media such as wireless LAN or PLC (Power Line Communications).

[0068] The devices 41, 42, 43, and 44 are general computers (such as PCs) or devices installed in a factory, and each has an IP address and a MAC address.

[0069] FIG. 2 is a diagram showing address information of location information acquisition terminal 20 and devices 41, 42, 43, and 44 according to this embodiment.

[0070] 2, device 41 has an IP address of "192.168.1.41" and a MAC address of "00:00:5E:00:53:41". Device 42 has an IP address of "192.168.1.42" and a MAC address of "00:00:5E:00:53:42". Device 43 has an IP address of "192.168.1.43" and a MAC address of "00:00:5E:00:53:43". Device 44 has an IP address of "192.168.1.44" and a MAC address of "00:00:5E:00:53:44". The IP address of the location information acquisition terminal 20 is "192.168.1.20" and the MAC address is "00:00:5E:00:53:20".

[0071] The IP address may be dynamically assigned by a router or may be statically set.

[0072] Returning to the explanation of Figure 1, the location information acquisition terminal 20 corresponds to a management device (also simply referred to as a management device) that manages the physical locations of devices installed in a factory. The location information acquisition terminal 20 has a function of acquiring the physical location information of a target device using the IP address of the device installed in the factory.

[0073] The location information acquisition terminal 20 may be in the form of a server that is always connected to the factory network 10 and periodically collects and manages physical location information of equipment in the factory, or it may be in the form of a wireless communication-capable terminal such as a tablet that connects to the factory network 10 to acquire physical location information when the physical location information of the target equipment is desired.

[0074] The location information relay device 31 is installed near the device 41. For example, the location information relay device 31 is installed in a location that is recognized as being near the device 41 by a person attempting to visually check the device 41 installed in a factory, in other words, the location information relay device 31 is installed in a location within a predetermined distance (for example, within several meters) from the device 41. Note that the separation distance between the device 41 and the location information relay device 31 is not limited to the above.

[0075] The location information relay device 31 is connected to a communication line (e.g., Ethernet) connecting the factory network 10 and the device 41. In other words, the location information relay device 31 is interposed between the device 41 and a network device included in the factory network 10. The location information relay device 31 mediates communication between the factory network 10 and the device 41. Specifically, the location information relay device 31 receives all communication packets addressed to the device 41 from the factory network 10 and forwards them to the device 41, and also receives communication packets from the device 41 and forwards them to the factory network 10. The location information relay device 31 recognizes the physical location information transmitted by any of the location information transmitters 51, 52, 53, and 54 to determine the physical location information of the device 41. At this time, the location information relay device 31 acquires the physical location information of the location information relay device 31 by recognizing the physical location information transmitted by any of the location information transmitters 51, 52, 53, and 54, and determines the location information as the physical location information of the device 41.

[0076] Furthermore, when a location information acquisition terminal 20 makes an inquiry about physical location information using the IP address of device 41 as a key, location information relay device 31 transmits the physical location information of device 41 on behalf of device 41.

[0077] Position information relay device 32 is installed near device 42. The positional relationship between position information relay device 32 and device 42 is the same as the description of the positional relationship between position information relay device 31 and device 41.

[0078] The location information relay device 32 is connected to a communication line (e.g., Ethernet) connecting the factory network 10 and the device 42. The location information relay device 32 mediates communication between the factory network 10 and the device 42. Specifically, the location information relay device 32 receives all communication packets addressed to the device 42 from the factory network 10 and forwards them to the device 42, and also receives communication packets from the device 42 and forwards them to the factory network 10. The location information relay device 32 recognizes the physical location information transmitted by any of the location information transmitters 51, 52, 53, and 54, thereby determining the physical location information of the device 42. At this time, the location information relay device 32 obtains the physical location information of the location information relay device 32 by recognizing the physical location information transmitted by any of the location information transmitters 51, 52, 53, and 54, and determines the location information as the physical location information of the device 42.

[0079] Furthermore, when a location information acquisition terminal 20 inquires about physical location information using the IP address of device 42 as a key, location information relay device 32 transmits the physical location information of device 42 instead of device 42.

[0080] Position information relay device 33 is installed near device 43. The positional relationship between position information relay device 33 and device 43 is the same as the description of the positional relationship between position information relay device 31 and device 41.

[0081] The location information relay device 33 is connected to a communication line (e.g., Ethernet) connecting the factory network 10 and the device 43. The location information relay device 33 mediates communication between the factory network 10 and the device 43. Specifically, the location information relay device 33 receives all communication packets addressed to the device 43 from the factory network 10 and forwards them to the device 43, and also receives communication packets from the device 43 and forwards them to the factory network 10. The location information relay device 33 recognizes the physical location information transmitted by any of the location information transmitters 51, 52, 53, and 54, thereby determining the physical location information of the device 43. At this time, the location information relay device 33 obtains the physical location information of the location information relay device 33 by recognizing the physical location information transmitted by any of the location information transmitters 51, 52, 53, and 54, and determines the location information as the physical location information of the device 43.

[0082] Furthermore, when a location information acquisition terminal 20 inquires about physical location information using the IP address of device 43 as a key, location information relay device 33 transmits the physical location information of device 43 on behalf of device 43.

[0083] In this way, location information relays 31, 32, and 33 are connected to factory network 10 and devices 41, 42, and 43 via communication lines such as Ethernet cables and perform IP communication. At this time, location information relay 31 communicates on behalf of device 41, location information relay 32 communicates on behalf of device 42, and location information relay 33 communicates on behalf of device 43. In other words, location information relays 31, 32, and 33 send communication packets using the IP addresses or MAC addresses of devices 41, 42, and 43 as the source IP addresses or source MAC addresses, respectively. Therefore, location information relays 31, 32, and 33 do not need to have their own IP addresses or MAC addresses, respectively.

[0084] However, there may be cases where communication is not possible without an IP address and a MAC address due to protocol stack restrictions, in which case location information relay devices 31, 32, and 33 may each have an IP address and a MAC address.

[0085] Furthermore, power may be supplied to each of the location information relay devices 31, 32, and 33 from a power outlet, or may be supplied via an Ethernet cable using PoE (Power over Ethernet).

[0086] Location information transmitters 51, 52, 53, and 54 are installed in each of the four divided areas and transmit physical location information indicating the area in which they are installed. For example, location information transmitter 51 is installed in Block A of Zone 1, so it transmits "1A" as its physical location information. Location information transmitter 52 is installed in Block B of Zone 1, so it transmits "1B" as its physical location information. Location information transmitter 53 is installed in Block A of Zone 2, so it transmits "2A" as its physical location information. Location information transmitter 54 is installed in Block B of Zone 2, so it transmits "2B" as its physical location information.

[0087] In this example, the physical location information is a string that combines a zone identifier (1 or 2) and a block identifier (A or B), such as "1A," "1B," or "2B." However, the location information is not limited to this and may be a string or number that can identify the physical location.

[0088] Each of the location information transmitters 51, 52, 53, and 54 transmits a signal (also referred to as a location information signal) including information specific to the location where the device is installed. Each of the location information transmitters 51, 52, 53, and 54 is, for example, a lighting device, stores physical location information data indicating an area in advance, and modulates illumination light based on the location information data and outputs it using an LED (Light Emitting Diode) or the like.

[0089] The method of transmitting physical location information from location information transmitters 51, 52, 53, and 54 is not limited to this. For example, location information may be transmitted using near-field communication (NFC), radio frequency identification (RFID), infrared, specific small radio, Bluetooth (registered trademark), Wi-Fi (registered trademark), Wi-SUN (registered trademark), ZigBee (registered trademark), or other short-range wireless communication technologies. Transmission may also be performed using on-site equipment, such as embedding the transmitter in a power outlet and transmitting via PLC communication, transmitting via sound waves, or displaying a QR code (registered trademark). Transmission may also be performed using off-site equipment, such as satellite communication such as GPS (Global Positioning System), wireless Metropolitan Area Networks (MANs) such as Wi-MAX, or wireless Wide Area Networks (WANs) such as 3G, 4G, LTE (registered trademark), or 5G.

[0090] The location information transmitted by the location information transmitters 51, 52, 53 and 54 using illumination light or other transmission methods can be received by the devices 41, 42 or 43.

[0091] Moreover, the location information transmitters 51, 52, 53 and 54 do not perform IP communication and are therefore not connected to the factory network 10.

[0092] Furthermore, the location information transmitters 51, 52, 53, and 54 may be installed inside a facility (for example, a factory) or outside the facility.

[0093] [1.2 Overall configuration of location information acquisition terminal 20] Fig. 3 is a configuration diagram showing the configuration of location information acquisition terminal 20. In Fig. 3, location information acquisition terminal 20 includes location information management unit 201, communication unit 202, and storage unit 203. Location information acquisition terminal 20 can be realized by a computer including a processor (such as a CPU (Central Processing Unit)), a memory, etc., executing a program.

[0094] The communication unit 202 is a communication interface, connected to the factory network 10, and communicates with devices belonging to the factory network 10 via the factory network 10. The communication standard used by the communication unit 202 is wired communication, such as IEEE802.3 (Ethernet), but is not limited to this. Other wired communication such as PLC may also be used, or wireless LAN communication in the IEEE802.11 series (IEEE802.11a, b, g, n, ac, ax, etc.).

[0095] The location information management unit 201 transmits a location information acquisition request and receives a location information acquisition response via the communication unit 202. The location information management unit 201 then stores in the storage unit 203 a location information list for managing the physical location information of the device obtained from the location information acquisition response.

[0096] The storage unit 203 stores a location information list that manages the physical location information obtained by the location information management unit 201 .

[0097] Fig. 4 is a diagram showing an example of a location information list. The location information list in Fig. 4 stores physical location information linked to the IP address and MAC address of each of devices 41, 42, 43, and 44. In Fig. 4, for example, physical location information "1A" is linked to the IP address "192.168.1.41" and the MAC address "00:00:5E:00:53:41."

[0098] If no location information is obtained, it is saved as "None." Instead of "None," other strings such as "-" or "NULL" can be used.

[0099] [1.3 Overall configuration of location information relay device 31] Fig. 5 is a configuration diagram of location information relay device 31. In Fig. 5, location information relay device 31 includes location information grasping unit 311, location information relay unit 312, communication unit 313, and storage unit 314. Location information relay device 31 can be realized by a computer including a processor (such as a CPU) and memory executing a program.

[0100] The position information ascertaining unit 311 ascertains the position information of the device 41. The position information ascertaining unit 311 may also be simply referred to as an ascertaining unit.

[0101] The location information grasping unit 311 has a sensor that receives a signal including physical location information transmitted by the location information transmitter 51. The location information grasping unit 311 grasps the location information of the device 41 from the signal received by the sensor and stores the information in the memory unit 314. Specifically, the location information grasping unit 311 receives the light output by the location information transmitter 51, converts the received light into an electrical signal, and demodulates it to obtain location information. Since visible light has an extremely high directivity, the location information grasping unit 311 obtains only the location information of location information transmitters 51 that are located near the location information relay device 31.

[0102] The communication unit 313 is a communication interface, and is connected to both the factory network 10 and the devices 41. The communication unit 313 communicates with devices belonging to the factory network 10 via the factory network 10. The communication standard used by the communication unit 313 is, for example, wired communication represented by IEEE802.3 (Ethernet), but is not limited to this. Other wired communication such as PLC may also be used, or wireless LAN communication of the IEEE802.11 series (IEEE802.11a, b, g, n, ac, ax, etc.).

[0103] The location information relay unit 312 transmits the location information to the network device. The location information relay unit 312 receives a communication packet transmitted from the device 41 to the network device, includes the location information in the received communication packet, and transmits the communication packet including the location information to the network device. The location information relay unit 312 is also simply referred to as a relay unit.

[0104] Specifically, the location information relay unit 312 relays communication between the factory network 10 and the device 41 via the communication unit 313. The location information relay unit 312 receives communication packets addressed to the device 41 from devices belonging to the factory network 10 and forwards them to the device 41. The location information relay unit 312 also receives communication packets from the device 41 and forwards them to the device that is the destination of the communication packets.

[0105] Location information relay unit 312 determines whether the received communication packet is a location information acquisition request, and if it determines that the packet is a location information acquisition request from location information acquisition terminal 20, it stores in memory unit 314 a location information conversion list created by pairing the "source MAC address" in the header of the location information acquisition request with a management flag obtained from the payload, and forwards the location information acquisition request to device 41. The management flag is flag information that is set to ON if the "source MAC address" is the address of the device that sent the location information acquisition request, and is set to OFF if not.

[0106] Furthermore, when the location information relay unit 312 receives a location information acquisition response from the device 41 , the location information relay unit 312 transfers the location information acquisition response to the location information acquisition terminal 20 while including the physical location information stored in the storage unit 314 in the location information acquisition response.

[0107] More specifically, location information relay unit 312 identifies a command of the network protocol used in the communication packet received from device 41, and determines whether the identified network protocol command is a predetermined command. If location information relay unit 312 determines that the identified network protocol command is a predetermined command, it includes location information in a predetermined field included in the communication packet.

[0108] In addition, the location information relay unit 312 receives, as a communication packet, a response packet that is sent by the device 41 to the location information acquisition terminal 20 in response to the request packet of the above network protocol, and that includes a response command defined by the above network protocol.

[0109] Furthermore, when the location information relay unit 312 receives a request packet of the above-mentioned network protocol, it determines whether a predetermined code is included in a predetermined field in the received request packet. If it determines that the received request packet contains the predetermined code, it receives a response packet as a communication packet, the source of which is the device 41 set as the destination of the received request packet, includes the location information in the received communication packet, and transmits the communication packet with the included location information to the network device.

[0110] The storage unit 314 stores the location information received by the location information grasping unit 311. The storage unit 314 stores a location information conversion list created by the location information relay unit 312.

[0111] An example of the location information conversion list is shown in Figure 6. The location information conversion list in Figure 6 registers the "source MAC address" in the header of the location information acquisition request and the management flag obtained from the payload.

[0112] Note that location information relays 32 and 33 each have the same configuration as location information relay 31. However, location information relays 32 and 33 are different in that they are connected to devices 42 and 43, respectively, instead of device 41.

[0113] [1.4 Location Information Acquisition System Operation] FIG. 7 is a diagram showing a processing sequence of the position information acquisition system according to this embodiment.

[0114] The location information acquisition system executes at least four processes: a location information grasping process, a location information acquisition request transfer process, a location information acquisition response transfer process, and a location information acquisition process.

[0115] The location information grasping process is a process in which the location information relay device 31 grasps and stores the physical location information of the device 41 connected thereto. By periodically performing this location information grasping process, the location information relay device 31 can grasp the latest physical location of the device 41. Note that the location information grasping process may be performed whenever the physical location information of the device 41 becomes necessary.

[0116] The location information acquisition process is a process in which the location information acquisition terminal 20 acquires the physical location of the device 41, 42, 43, or 44 in the factory network 10. Specifically, the location information acquisition terminal 20 transmits a location information acquisition request that sets the IP address of the device (also referred to as the target device) for which the location information is to be acquired, and receives a location information acquisition response that includes the physical location information of the device corresponding to the IP address, thereby acquiring the physical location information of the target device.

[0117] In this embodiment, the location information acquisition process uses communication packets of ARP (Address Resolution Protocol), a common network protocol, as the location information acquisition request and the location information acquisition response. In this case, the request command and response command defined by the network protocol are an ARP request and an ARP response, respectively.

[0118] Here, Fig. 8 is a diagram showing the packet format of an ARP request packet (also called "ARP request"), and Fig. 9 is a diagram showing the packet format of an ARP response packet (also called "ARP response").

[0119] ARP is a network protocol that allows a device attempting address resolution (also called the ARP request source device) to obtain the MAC address of a device (also called the target device) that matches a target IP address. In ARP communication, the ARP request source device first sets the target IP address in the payload of the ARP request and broadcasts it to all devices on the factory network 10. Of the devices that receive the ARP request, the device that matches the target IP address returns an ARP response to the ARP request source device, with its own MAC address set as the "source MAC address" in the payload. The ARP request source device obtains the "source MAC address" in the payload of the ARP response as the MAC address of the target device.

[0120] The location information acquisition system of this embodiment uses an ARP request format for a location information acquisition request, and an ARP response format for a location information acquisition response.

[0121] When the device 41 receives the ARP request transmitted by the position information acquisition terminal 20, it transmits an ARP response to the position information acquisition terminal 20 as a response to the received ARP request.

[0122] Returning to the explanation of Fig. 7, the location information acquisition request transfer process and the location information acquisition response transfer process are processes by which the location information acquisition terminal 20 acquires the physical location information of the device 41. Specifically, the location information relay device 31 interrupts the communication of the location information acquisition request and the location information acquisition response as ARP communication between the location information acquisition terminal 20 and the device 41, replaces the "source MAC address" in the payload of the ARP response from the MAC address of the device 41 with the physical location information of the device 41, and transmits the location information acquisition response to the location information acquisition terminal 20. In this way, the location information acquisition terminal 20 acquires the physical location information of the device 41.

[0123] The function to perform ARP communication is always implemented in devices that communicate over a network, so by using this ARP, it is possible to obtain physical location information without replacing devices installed in the factory or installing any programs.

[0124] Although ARP is used in this embodiment, other common network protocols such as Ping (ICMP Echo) may also be used.

[0125] The details of each process will be explained below with reference to the drawings.

[0126] [1.4.1 Location information acquisition process] Fig. 10 is a flowchart of the location information acquisition process, Fig. 11 is a diagram showing an example of a packet for a location information acquisition request, and Fig. 12 is a diagram showing an example of a packet for a location information acquisition response.

[0127] In step S11, the location information management unit 201 sets the IP address of the target device for which physical location information is to be obtained as the "target IP address," creates a location information acquisition request packet (also called a location information acquisition request) with the management flag set to ON, and sends it to the factory network 10 via the communication unit 202.

[0128] FIG. 11 is a diagram illustrating an example of a location information acquisition request packet according to the embodiment.

[0129] As shown in FIG. 11, in this embodiment, as an example, the "target MAC address" in the payload of the ARP request, which is a location information acquisition request packet, is used as information indicating the management flag. In a normal ARP request, the "target MAC address" is set to "00:00:00:00:00:00" or, depending on the implementation, "FF:FF:FF:FF:FF:FF." Therefore, a target MAC address of "00:00:00:00:00:00" or "FF:FF:FF:FF:FF:FF" indicates that the management flag is OFF. Information set in the target MAC address field other than the above indicates that the management flag is ON.

[0130] For example, information indicating that the management flag is ON is "FF:FF:FF:FF:FF:FE" (see FIG. 11), which is also called a management code or a predetermined code. The location information management unit 201 sets the management flag of the ARP request to ON by setting the management code to the "target MAC address" in the payload of the ARP request. Also, the location information management unit 201 sets the management flag of the ARP request to OFF by setting "00:00:00:00:00:00" to the "target MAC address" in the payload of the ARP request.

[0131] Note that instead of "FF:FF:FF:FF:FF:FE", other codes may be used as the management code indicating that the management flag is ON.

[0132] In step S12, location information management unit 201 waits to receive a location information acquisition response packet (also referred to as a "location information acquisition response"). Location information management unit 201 determines whether or not the location information acquisition response packet has been received before the response reception timeout. If the location information acquisition response packet has been received before the response reception timeout (Yes in step S12), the process proceeds to step S13; if not (No in step S12), the series of processes shown in FIG. 10 ends.

[0133] In step S13, location information management unit 201 determines whether or not the location information acquisition response packet includes physical location information. Specifically, if the "source MAC address" in the header of the location information acquisition response packet is different from the "source MAC address" in the payload, location information management unit 201 determines that the location information acquisition response packet includes physical location information, and if the "source MAC address" in the header of the location information acquisition response packet is the same as the "source MAC address" in the payload, location information management unit 201 determines that the location information acquisition response packet does not include location information. If location information management unit 201 determines that the location information acquisition response packet includes physical location information (Yes in step S13), it proceeds to step S14; if not (No in step S13), it proceeds to step S15.

[0134] FIG. 12 is a diagram showing an example of a location information acquisition response packet in this embodiment.

[0135] 12, the "source MAC address" in the header of the location information acquisition response packet is different from the "source MAC address" in the payload. Specifically, "00:00:5E:00:53:41," which is the "source MAC address" in the header of the location information acquisition response packet, is the MAC address of device 41, and "1A:00:5E:00:53:41," which is included in the "source MAC address" field in the payload, is the MAC address of device 41 with the first octet of the MAC address changed to "1A." This is because location information relay unit 312 has stored "1A," which is the physical location information of device 41, in the first octet of the "source MAC address" in the payload.

[0136] In step S14, location information management unit 201 registers a pair of the "source MAC address" in the header of the location information acquisition response packet and the "location information" and "source IP address" in the payload in the location information list of storage unit 203. The location information list registered from the location information acquisition response packet in FIG. 12 corresponds to the first one in FIG. 4.

[0137] There are also devices in the factory, such as device 44, that are not connected to a location information relay device. In the case of such devices, the location information acquisition response packet does not include physical location information, and therefore the location information acquisition response packet does not include physical location information, and the MAC address of the device remains stored in the "source MAC address" in the payload. In other words, the "source MAC address" in the header of the location information acquisition response packet is the same as the "source MAC address" in the payload. In this case, the determination result in step S13 is No, and the process proceeds to step S15.

[0138] In step S15, location information management unit 201 registers a pair of the "source MAC address" in the header of the location information acquisition response packet and the "source IP address" in the payload in the location information list of storage unit 203, and registers "none" as the physical location information. The location information list registered from this location information acquisition response packet corresponds to the fourth item in Figure 4.

[0139] The timing at which the location information management unit 201 transmits the location information acquisition request packet may be when an instruction from a user is received from an instruction receiving unit (not shown) of the location information acquisition terminal 20, or may be at regular intervals.

[0140] [1.4.2 Location information processing] FIG. 13 is a flowchart showing the location information grasping process of the location information grasping unit 311.

[0141] In this embodiment, a lighting device is used as the location information transmitter 51, and the location information grasping unit 311 performs location information grasping processing using visible light communication with the illumination light. The location information transmitter 51 modulates and transmits the illumination light using a binary signal obtained by binarizing the location information (i.e., "1A") indicating the physical location that has been input in advance. The location information grasping unit 311 has a light receiving unit for the illumination.

[0142] In step S21, the position information determination unit 311 determines whether or not a position information signal has been received via the light receiving unit from the position information transmitter 51. If it is determined that a position information signal has been received (Yes in step S21), the process proceeds to step S22; if not (No in step S21), the process executes step S21 again. In other words, the position information determination unit 311 waits in step S21 until it receives a position information signal.

[0143] In step S22, the position information determination unit 311 analyzes the position information included in the position information signal. Specifically, the position information determination unit 311 demodulates the illumination light into a binary signal, and further demodulates it into a position information signal to obtain the position information.

[0144] In step S23, the location information ascertaining unit 311 determines whether or not the location information has been ascertained. If the location information has been ascertained (Yes in step S23), the process proceeds to step S24; if not (No in step S23), the process proceeds to step S25.

[0145] In step S24, the location information grasping unit 311 registers "1A" in the storage unit 314 as location information.

[0146] In step S25, the location information grasping unit 311 registers data indicating "unknown" as the location information. By periodically performing this location information grasping process, it becomes possible to keep up with the latest information even if the location information changes.

[0147] Although "unknown" is used as data indicating that the location information is unknown, a character string such as "-" or NULL may also be stored.

[0148] Although the example in which the location information transmitter 51 modulates the illumination light with a binary signal that binarizes the location information has been described, other methods may be used. For example, the location information transmitter 51 may set the number of flashes or the lighting duration of the illumination light based on the location information, and the location information may be determined by the location information relay device 33 based on the number of flashes or the lighting duration of the illumination light. The location information transmitter 51 may notify the location information according to a predetermined lighting or flashing pattern, for example, by distinguishing zones based on the number of flashes, such as "Zone 1" for one flash every 10 seconds and "Zone 2" for two flashes every 10 seconds, and by the lighting duration, such as "Zone A" for two seconds and "Zone B" for five seconds. Note that the number of flashes or the lighting duration are merely examples and are not limiting.

[0149] When the location information transmitter 51 notifies location information by the number of flashes or the lighting time, the location information grasping unit 311 has a light receiving unit which is a sensor that receives illumination light, and grasps the location information of the device from the interval between flashes or the lighting time of the light received by the light receiving unit. For example, if the location information transmitter 51 flashes twice in 10 seconds with a lighting time of 2 seconds, the location information grasping unit 311 grasps the location information as "Block A of Zone 2," or "2A."

[0150] [1.4.3 Location information request transfer process] FIG. 14 is a flowchart showing the location information acquisition request transfer process of location information relay unit 312.

[0151] In step S31, location information relay unit 312 determines whether or not an ARP request has been received. If it is determined that an ARP request has been received (Yes in step S31), the process proceeds to step S32; if not (No in step S31), step S31 is executed again. In other words, location information relay unit 312 waits in step S31 until an ARP request is received.

[0152] In step S32, the location information relay unit 312 determines whether the target MAC address in the payload of the ARP request packet received in step S31 matches the management code (in other words, whether the ARP request indicates that the management flag is ON). If it is determined that the target MAC address does not match the management code (in other words, if the ARP request indicates that the management flag is OFF) (No in step S32), the process proceeds to step S33. If it is determined that the target MAC address matches the management code (in other words, if the ARP request indicates that the management flag is ON) (Yes in step S32), the process proceeds to step S35.

[0153] In step S33, location information relay unit 312 pairs the "source MAC address" in the header of the ARP request packet with information indicating "management flag: OFF", and registers the pair in the location information conversion list stored in storage unit 314. This is because the ARP request received in step S31 is an ARP request from a device other than location information acquisition terminal 20.

[0154] In step S34, the location information relay unit 312 transfers the ARP request packet received in step S31 to the device 41 without making any changes thereto.

[0155] In step S35, location information relay unit 312 pairs the "source MAC address" in the header of the ARP request packet with information indicating "management flag: ON", and registers the pair in the location information conversion list stored in storage unit 314. This is because the ARP request received in step S31 is an ARP request from location information acquisition terminal 20.

[0156] In step S36, location information relay unit 312 changes the management flag of the ARP request to OFF and forwards it to device 41. That is, in the case of Fig. 11, location information relay unit 312 changes the target MAC address "FF:FF:FF:FF:FF:FE" used as the management code to "00:00:00:00:00:00", thereby forwarding it to device 41 as an ARP request having the format of a normal ARP request packet.

[0157] [1.4.4 Operation when transferring location information response] FIG. 15 is a flowchart showing the location information acquisition response transfer process of location information relay unit 312.

[0158] In step S41, location information relay unit 312 determines whether or not an ARP response has been received. If it is determined that an ARP response has been received (Yes in step S41), the process proceeds to step S42; if not (No in step S41), step S41 is executed again. In other words, location information relay unit 312 waits in step S41 until an ARP response is received.

[0159] In step S42, location information relay unit 312 searches for the "destination MAC address" in the header of the ARP response packet received in step S41 in the location information conversion list stored in memory unit 314, and determines whether the management flag for that "destination MAC address" is OFF or ON. If the management flag is OFF ("OFF" in step S42), the process proceeds to step S43, and if the management flag is ON ("ON" in step S42), the process proceeds to step S44.

[0160] In step S43, the location information relay unit 312 transfers the ARP response packet to the destination device without making any changes to it, because the ARP response received in step S41 is an ARP response in normal ARP communication.

[0161] In step S44, location information relay unit 312 acquires the physical location information of device 41 stored in storage unit 314. The ARP response received in step S41 is not an ARP response in normal ARP communication, but an ARP response that functions as a response to a location information acquisition request transmitted by location information acquisition terminal 20 to acquire the location information of device 41, and the request source is location information acquisition terminal 20.

[0162] In step S45, location information relay unit 312 creates a location information acquisition response by including the physical location information of device 41 in the "source MAC address" field of the ARP response packet (for example, by rewriting part or all of the "source MAC address" field with the physical location information of device 41), and transfers it to location information acquisition terminal 20. Note that there are cases where "unknown" is stored as the physical location information, and in this case, location information relay unit 312 creates and transfers a location information acquisition response by rewriting part or all of the "source MAC address" field of the ARP response packet with information meaning "unknown."

[0163] It should be noted that location information relay devices 32 and 33 each perform the same processing as location information relay device 31 and operate independently of location information relay device 31.

[0164] [1.4.5 Example of a location information acquisition system sequence (1)] FIG. 16 shows a sequence example (1) of the position information acquisition system according to this embodiment.

[0165] Using FIG. 16, the sequence of the entire location information acquisition system when location information acquisition terminal 20 acquires location information of device 41 connected to location information relaying device 31 will be described.

[0166] In step S101, the positional information relay device 31 performs a positional information grasping process in advance. Specifically, the positional information grasping unit 311 receives a positional information signal from the positional information transmitter 51.

[0167] In step S102, the location information relaying device 31 extracts the location information from the location information signal received in step S101, and registers the location information "1A" in the storage unit 314.

[0168] In step S103, the location information management unit 201 of the location information acquisition terminal 20 sets the IP address of the device 41 as the target IP address, and broadcasts an ARP request packet with the management flag set to ON as a location information acquisition request packet via the communication unit 202.

[0169] In step S104, the location information relay unit 312 of the location information relay device 31 that received the ARP request via the communication unit 313 determines that the ARP request is a location information acquisition request sent from the location information acquisition terminal 20 based on the fact that the management flag of the ARP request is ON, and pairs the ``source MAC address'' in the header of the location information acquisition request packet (specifically, 00:00:5E:00:53:20, which is the MAC address of the location information acquisition terminal 20) with information indicating ``management flag: ON'', and registers this pair in the location information conversion list stored in the memory unit 314.

[0170] In step S105, the location information relay unit 312 changes the management flag of the location information acquisition request packet to OFF, and transfers the packet to the device 41 via the communication unit 313.

[0171] In step S 106 , the location information relay unit 312 receives the ARP response packet from the device 41 via the communication unit 313 .

[0172] In step S107, location information relay unit 312 searches the location information conversion list stored in storage unit 314 using the "destination MAC address" in the header of the ARP response packet received in step S106 (specifically, 00:00:5E:00:53:20, which is the MAC address of location information acquisition terminal 20) as a key, and acquires the management flag associated with the destination MAC address. Here, location information relay unit 312 acquires that the management flag is ON.

[0173] In step S108, the location information relay unit 312 acquires the location information of the device 41 stored in the storage unit 314.

[0174] In step S109, the location information relay unit 312 creates a location information acquisition response by rewriting the first octet of the “source MAC address” of the ARP response packet to “1A”, which is the location information, and transfers it to the location information acquisition terminal 20 via the communication unit 313.

[0175] In step S110, the location information management unit 201 of the location information acquisition terminal 20 that has received the location information acquisition response via the communication unit 202 determines that the ARP response packet contains location information based on the fact that the "source MAC address" in the header of the ARP response packet is different from the "source MAC address" in the payload, and registers the three items, namely the "source MAC address" in the header of the location information acquisition response, the "location information" "1A" in the payload, and the "source IP address," in the location information acquisition response in a location information list stored in the memory unit 203 as a set.

[0176] [1.4.6 Example of a location information acquisition system sequence (2)] FIG. 17 shows a sequence example (2) of the position information acquisition system according to this embodiment.

[0177] Hereinafter, the sequence of the entire location information acquisition system when location information acquisition terminal 20 fails to acquire physical location information of device 44 that is not connected to a location information relay will be described with reference to FIG.

[0178] In step S201, the location information management unit 201 of the location information acquisition terminal 20 sets the IP address of the device 44 as the target IP address, and broadcasts an ARP request with the management flag set to ON via the communication unit 202 as a location information acquisition request.

[0179] In step S202, the device 44 that has received the ARP request packet transmits an ARP response including its own MAC address to the position information acquisition terminal 20 based on the fact that the target IP address in the ARP request matches its own IP address.

[0180] In step S203, the location information management unit 201 receives the ARP response packet from the device 41 via the communication unit 202. Based on the fact that the "source MAC address" in the header of the ARP response packet matches the "source MAC address" in the payload, the location information management unit 201 determines that the ARP response packet does not contain physical location information, and registers the "source MAC address" in the header of the location information acquisition response, the "source IP address" in the payload, and "none" as the physical location information in the memory unit 203.

[0181] In this way, sending a location information acquisition request using an ARP request packet in this embodiment does not adversely affect the ARP communication of devices that are not connected to the location information relay device.

[0182] [1.4.7 Example of a location information acquisition system sequence (3)] FIG. 18 shows a sequence example (3) of the position information acquisition system according to this embodiment.

[0183] An example of the sequence of the entire location information acquisition system when device 44 performs ARP communication with device 41 connected to location information relaying device 31 will be described with reference to FIG.

[0184] In steps S301 and S302, location information relay device 31 performs location information grasping processing. Specifically, location information grasping unit 311 receives a location information signal from location information transmitter 51 (step S301), extracts location information from the received location information signal, and registers the location information “1A” in storage unit 314 (step S302).

[0185] In step S303, the device 44 broadcasts an ARP request packet in which the IP address of the device 41 is set as the target IP address.

[0186] In step S304, the location information relay unit 312 of the location information relay device 31 that received the ARP request via the communication unit 313 determines that the ARP request is an ARP request sent from a device other than the location information acquisition terminal 20 based on the fact that the management flag of the ARP request is OFF, and pairs the ``source MAC address'' in the header of the ARP request (specifically, 00:00:5E:00:53:44, which is the MAC address of device 44) with information indicating ``management flag: OFF'', and registers this pair in the location information conversion list stored in the memory unit 314.

[0187] In step S305, the location information relay unit 312 transfers the ARP request packet to the device 41 via the communication unit 313 without making any changes to the packet.

[0188] In step S 306 , the location information relay unit 312 receives the ARP response packet from the device 41 via the communication unit 313 .

[0189] In step S307, location information relay unit 312 searches the location information conversion list stored in memory unit 314 using the "destination MAC address" in the header of the ARP response packet received in step S306 (specifically, 00:00:5E:00:53:44, which is the MAC address of device 44) as a key, and acquires the management flag associated with the destination MAC address. Here, location information relay unit 312 acquires that the management flag is OFF.

[0190] In step S308, the location information relay unit 312 transfers the ARP response packet to the device 44 via the communication unit 313 without modifying it.

[0191] In this way, sending a location information acquisition request using an ARP request packet in this embodiment does not adversely affect normal ARP communications between devices.

[0192] As described above, the location information relay device in this embodiment contributes to the appropriate understanding of location information of connected devices.

[0193] In this embodiment, the location information acquisition system targets the factory network 10, but this is one aspect of the location information acquisition system and is not limited to factory networks. For example, the system may target other network fields as long as a plurality of devices are connected to a network such as a building network, a home network, or a vehicle network and the physical location information of the devices can be acquired via the network.

[0194] In the above-described embodiments, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. Here, the software that realizes the content management system of the above-described embodiments is a program such as the following.

[0195] In other words, this program causes a computer to execute a location information relay method executed by a location information relay device interposed between a network device and a device, which determines the location information of the device, receives a communication packet sent by the device to the network device, includes the location information in the received communication packet, and sends the communication packet with the location information included to the network device.

[0196] Although the information processing method according to one or more aspects has been described based on the embodiments, the present invention is not limited to these embodiments. As long as it does not deviate from the spirit of the present invention, various modifications conceivable by those skilled in the art to the present embodiments, or forms constructed by combining components of different embodiments, may also be included within the scope of one or more aspects. [Industrial Applicability]

[0197] The present invention can be applied to industries that build networks equipped with terminals that have IP addresses. [Explanation of symbols]

[0198] 10 Factory Network 20 Location information acquisition device 31, 32, 33 Location information relay device 41, 42, 43, 44 equipment 51, 52, 53, 54 Location information transmitter 201 Location information management department 202, 313 Communications Department 203, 314 Storage section 311 Location information grasping unit 312 Location Information Relay Unit

Claims

1. A location information relay device interposed between a network device and a device, a recognition unit that recognizes location information of the device; a relay unit that receives a communication packet transmitted from the device to the network device, includes the location information in the received communication packet, and transmits the communication packet including the location information to the network device; The relay unit is When it is determined that the command of the network protocol used in the received communication packet is a predetermined command, the location information is included in a predetermined field included in the communication packet. Location information relay device.

2. The location information relay device is installed within a predetermined distance from the device, The grasping unit a sensor for acquiring location information of the location information relay device; The location information of the location information relay device acquired by the sensor is grasped as the location information of the device. The location information relay device according to claim 1 .

3. A location information relay device interposed between a network device and a device, a recognition unit that recognizes location information of the device; a relay unit that receives a communication packet transmitted from the device to the network device, includes the location information in the received communication packet, and transmits the communication packet including the location information to the network device; The relay unit is Identifying a command of a network protocol used in the received communication packet; determining whether the command of the identified network protocol is a predetermined command; If it is determined that the command of the identified network protocol is the predetermined command, the location information is included in a predetermined field included in the communication packet. Location information relay device.

4. A location information relay device interposed between a network device and a device, a recognition unit that recognizes location information of the device; a relay unit that receives a communication packet transmitted from the device to the network device, includes the location information in the received communication packet, and transmits the communication packet including the location information to the network device; the device is connected to a management device via one or more of the network devices; the management device transmits a request packet including a request command defined by a network protocol to the device; The relay unit is receiving the request packet and transmitting it to the device; A response packet transmitted from the device to the management device in response to the request packet, the response packet including a response command defined by the network protocol, is received as the communication packet. Location information relay device.

5. When the relay unit receives the request packet, the relay unit determines whether a predetermined code is included in a predetermined field in the received request packet; When it is determined that the received request packet contains the predetermined code, the response packet is received as the communication packet, with the device set as the destination of the received request packet as the sender, the location information is included in the received communication packet, and the communication packet with the location information included is transmitted to the network device. The location information relay device according to claim 4.

6. The grasping unit A transmitter transmits a signal including information specific to the location where the transmitter is installed. The signal transmitted by the transmitter is received, and the location information of the device is determined from the received signal. The location information relay device according to claim 1 .

7. The location information relay device further a storage unit for storing the location information obtained by the obtaining unit; The location information relay device according to claim 1 .

8. The network protocol is ARP (Address Resolution Protocol). The location information relay device according to claim 1 .

9. a network device; Equipment and a management device connected to the device via the network device; The location information relay device according to any one of claims 1 to 8 is provided between the network device and the device. Location information acquisition system.

10. A network device; Equipment and a management device connected to the device via the network device; a location information relay device interposed between the network device and the device, The location information relay device a recognition unit that recognizes location information of the device; a relay unit that receives a communication packet transmitted from the device to the network device, includes the location information in the received communication packet, and transmits the communication packet including the location information to the network device; The management device transmitting a request packet including request information, which is information requesting location information of the device, to the device; The relay unit is receiving the request packet transmitted by the management device and transmitting it to the device; The device comprises: receiving the request packet and transmitting a response packet to the management device as a response to the request packet; The relay unit is The response packet transmitted by the device is received as the communication packet, and the location information is included in the received response packet and transmitted to the management device. Location information acquisition system.

11. A network device; Equipment and a management device connected to the device via the network device; a location information relay device interposed between the network device and the device, The location information relay device a recognition unit that recognizes location information of the device; a relay unit that receives a communication packet transmitted from the device to the network device, includes the location information in the received communication packet, and transmits the communication packet including the location information to the network device; The management device includes a storage unit that stores the IP address, MAC address, and location information of the device in association with each other. Location information acquisition system.

12. The location information acquisition system further comprises: a transmitter that transmits a signal including information specific to a location where the transmitter is installed; The transmitter is installed in the facility. The location information acquisition system according to claim 9 .

13. The location information acquisition system further comprises: a transmitter that transmits a signal including information specific to a location where the transmitter is installed; The transmitter is installed outside the facility. The location information acquisition system according to claim 9 .

14. A location information relay method executed by a location information relay device interposed between a network device and a device, The location information of the device is obtained, receiving a communication packet transmitted by the device to the network device, including the location information in the received communication packet, and transmitting the communication packet including the location information to the network device; When including the location information, When it is determined that the command of the network protocol used in the received communication packet is a predetermined command, the location information is included in a predetermined field included in the communication packet. Location relay method.

15. A program that causes a computer to execute the location information relay method according to claim 14.

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