Communication control device, method, and program

Abstract

A communication control device is provided, comprising: a detection unit for detecting an output signal output from a device to a network; and a switching unit for connecting a first communication path from the network to the device when the output signal is detected by the detection unit, and disconnecting the first communication path when the output signal is no longer detected by the detection unit, wherein the switching unit switches between the connected state and the disconnected state by controlling the power supply to a repeater provided in the first communication path that relays signals from the network to the device.

Description

Technical Field

[0003]

[0001] The present invention relates to a communication control device, method, and program.

Background Art

[0002] Patent Document 1 etc. describes "a management unit that manages the state of commands used for the data communication... The connection unit disconnects the connected communication path and reconnects the disconnected communication path based on the state of the command" (Claim 1 of the cited document). [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2000-165474 [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2018-157366 [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2011-223386

Summary of the Invention

[0003] (1) In a first aspect of the present invention, there is provided a communication control device including a detection unit that detects an output signal output from a device to a network, and a switching unit that sets a first communication path from the network to the device to a connected state in response to the detection unit detecting the output signal, and sets the first communication path to a disconnected state in response to the detection unit no longer detecting the output signal.

[0004] (2) In the communication control device of (1) above, the switching unit may be provided in the first communication path and switch between the connected state and the disconnected state by controlling the power supply to a repeater that relays signals from the network to the device.

[0005] (3) The communication control device of (1) above further includes a switch provided in the first communication path for opening and closing the first communication path, and the switching unit may switch between the connected state and the disconnected state by controlling the switch.

[0006] (4) Any of the above communication control devices (1) to (3) may further include a link-up unit provided in the second communication path from the device to the network, which maintains the device in a state where it can transmit.

[0007] (5) In the communication control device described in (4) above, the link-up unit may output the output signal to the network in response to receiving the output signal from the device, and may also output a trigger signal to the detection unit, which may detect the trigger signal as the output signal.

[0008] (6) In the communication control device described in (4) or (5) above, the switching unit may set the portion of the second communication path between the link-up unit and the network to either a connected or disconnected state, together with the first communication path.

[0009] (7) In the communication control device described in (6) above, the first communication path and the second communication path may be a common communication path.

[0010] (8) Any of the above communication control devices (1) to (7) further includes a timing unit that measures the elapsed time since the detection unit detected an output signal, and the switching unit may disconnect the first communication path when the detection unit no longer detects an output signal and the elapsed time exceeds a reference time.

[0011] (9) In a second embodiment of the present invention, an apparatus is provided comprising a communication control device according to any of (1) to (8), and the device connected to the network.

[0012] (10) In a third aspect of the present invention, a network device is provided comprising a repeater provided between a device and a network for relaying signals between the device and the network, and a communication control device of any one of (1) to (8).

[0013] (11) A fourth aspect of the present invention provides a method comprising: a detection step of detecting an output signal output from a device to a network; and a switching step of connecting a first communication path from the network to the device in accordance with the detection of the output signal in the detection step, and disconnecting the first communication path in accordance with the detection of the output signal in the detection step.

[0014] (12) In a fifth aspect of the present invention, a program is provided which, when executed by a computer, causes the computer to function as a detection unit that detects an output signal output from a device to a network, and a switching unit that connects a first communication path from the network to the device when the output signal is detected by the detection unit, and disconnects the first communication path when the output signal is no longer detected by the detection unit.

[0015] It should be noted that the above summary of the invention does not list all the necessary features of the present invention. Furthermore, subcombinations of these features may also constitute an invention. [Brief explanation of the drawing]

[0016] [Figure 1] This shows System 1 according to the first embodiment. [Figure 2] This shows the operation of the communication control device 5. [Figure 3] System 1A relating to variation (1) is shown. [Figure 4] System 1B relating to variation (2) is shown. [Figure 5] System 1C according to the second embodiment is shown. [Figure 6]System 1D according to the third embodiment is shown. [Figure 7] An example of a computer 1200 in which multiple aspects of the present invention may be embodied in whole or in part is shown.

Embodiments of the Invention

[0017] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0018] (First Embodiment) FIG. 1 shows a system 1 according to this embodiment. The system 1 includes a network 10, a device 2, a repeater 3, a power supply 4, and a communication control device 5.

[0019] ((Network 10)) The network 10 connects the device 2 and one or more other devices (not shown) wirelessly or by wire. The network 10 may be the Internet, a wide area network, or a local area network, etc., and may include a mobile line network.

[0020] ((Device 2)) Device 2 is connected to network 10 and communicates with one or more other devices included in the network. Device 2 may communicate using a known communication standard such as Ethernet (e.g., 10Base-T or 100Base-TX). In this embodiment, for example, device 2 is an industrial, server, or office PC, and may send a file request signal (e.g., an email file) to a file server on network 10 (e.g., a mail server) at reference intervals and receive files from the file server. However, the communication content is not limited to this and may be any data file such as image data or computation data. Also, device 2 does not have to be a PC, but may be other types of devices capable of communication (e.g., measuring instruments, analyzers, control devices, POS registers, digital signage, etc.).

[0021] Device 2 may be connected to the network 10 via a wired communication path 15. The communication path 15 according to this embodiment may have a first communication path from the network 10 to device 2 (also referred to as a downlink path 16) and a second communication path from device 2 to the network 10 (also referred to as an uplink path 17). In this figure, the direction of communication via the downlink path 16 and the uplink path 17 is indicated by the direction of the dashed arrows.

[0022] ((Repeater 3)) Repeater 3 is installed on the downlink path 16 and relays signals from network 10 to device 2. In this embodiment, as an example, repeater 3 may be installed on the communication path 15 and relay signals between network 10 and device 2. Repeater 3 may be a network device, such as a router, hub, network switch, or firewall.

[0023] ((Power 4)) Power supply 4 supplies power to repeater 3. Power supply 4 may have a power switch 41 that switches the power supply to repeater 3 on and off. The power switch 41 may be a mechanical switch, a semiconductor switch, or a combination of these. Power supply 4 may also supply power to communication control device 5.

[0024] ((Communication control device 5)) The communication control device 5 is a device that controls communication between the device 2 and the network 10, and is installed in the communication path 15. The communication control device 5 has a link-up unit 51, a detection unit 52, a timing unit 53, and a switching unit 54. Although not shown in the figures, the communication control device 5 may be provided with connection terminals connected to the device 2 and connection terminals connected to the repeater 3.

[0025] (((Link-up section 51))) The link-up unit 51 is provided on the uplink path 17 from the device 2 to the network 10 and maintains the device 2 in a state where it can transmit. In this embodiment, as an example, the link-up unit 51 may be provided on the communication path 15 and maintain the device 2 in a state where it can send and receive. For example, the link-up unit 51 may be connected to the device 2 on both the uplink path 17 and the downlink path 16, and may dynamically assign an IP address to the device 2. The link-up unit 51 may periodically send link pulses (also called NLP) to the device 2 via the downlink path 16 to indicate that the communication path 15 is connected, and may similarly receive link pulses transmitted from the device 2 via the uplink path 17. The link-up unit 51 may also acquire a sequence of auto-negotiation pulses (also called FLP) (also called a link burst) from the device 2.

[0026] The link-up unit 51 may be capable of detecting output signals from the device 2 to the network 10 among the signals passing through the communication path 15. For example, the link-up unit 51 may detect data on the MII (Media Independent Interface) as an output signal. The link-up unit 51 does not need to detect the above-mentioned link burst and link pulse as output signals output from the device 2 to the network 10.

[0027] The link-up unit 51 may output an output signal from device 2 to network 10 and a trigger signal to the detection unit 52 when it receives an output signal from device 2 to network 10, and may also output a signal to device 2 when it receives a signal from network 10 to device 2. If the output signal cannot be output to network 10 because the uplink path 17 is disconnected, the link-up unit 51 may repeatedly cause device 2 to output the output signal, and when the uplink path 17 becomes connected, it may output the output signal from device 2 to network 10 and a trigger signal to the detection unit 52. Alternatively, the link-up unit 51 may buffer the output signal from device 2 before outputting it to network 10, and if the output signal cannot be output to network 10 because the uplink path 17 is disconnected, it may output the buffered output signal to network 10 and a trigger signal to the detection unit 52 when the uplink path 17 becomes connected.

[0028] The link-up unit 51 may include a hub controller chip (for example, a hub controller chip that supports 10BaseT or 100BaseTX communication methods). The trigger signal output from the link-up unit 51 may be an electrical signal or an optical signal output by a light-emitting device such as an LED.

[0029] (((Detection unit 52))) The detection unit 52 detects the output signal that is output from the device 2 to the network 10. For example, the detection unit 52 may detect the trigger signal output from the link-up unit 51 as an output signal. In response to detecting an output signal, the detection unit 52 may supply a detection signal to the switching unit 54 and the timing unit 53 to indicate that it has detected an output signal.

[0030] Here, the output signal that is sent from device 2 to network 10 may be a signal used for data communication. A sequence of pulses for auto-negotiation (also called FLP) (also called link burst) and a link pulse (also called NLP) that indicates that the communication path 15 is connected are output from device 2 to the link-up unit 51 and do not have to be an output signal sent from device 2 to network 10.

[0031] (((Timekeeping section 53))) The timing unit 53 measures the elapsed time since the output signal was detected by the detection unit 52. The timing unit 53 may start measuring the elapsed time in response to the detection of the output signal. The timing unit 53 may reset the measured elapsed time each time the output signal is detected. This allows the timing unit 53 to measure the elapsed time since the last detection when the output signal is detected intermittently. The timing unit 53 may supply the measured elapsed time to the switching unit 54.

[0032] (((Switching section 54))) The switching unit 54 connects the downlink path 16 when the detection unit 52 detects an output signal, and disconnects the downlink path 16 when the detection unit 52 no longer detects an output signal. The switching unit 54 may also disconnect the downlink path 16 when the detection unit 52 no longer detects an output signal and the elapsed time exceeds a reference time. The switching unit 54 may perform the switching based on the detection signal supplied from the detection unit 52. The reference time may be set in advance to any length between 1 second and 10 minutes, and may be longer than the timeout period specified by TCP (Transmission Control Protocol) (for example, 180 seconds).

[0033] The switching unit 54 may connect or disconnect the portion of the uplink path 17 between the link-up unit 51 and the network 10, along with the downlink path 16. In this embodiment, the switching unit 54 may switch between the connected and disconnected states by controlling the power supply to the repeater 3. In this embodiment, as an example, the switching unit 54 may switch the downlink path 16 and the uplink path 17 to the connected or disconnected state by switching the power switch 41 on or off in the power supply 4.

[0034] According to the communication control device 5 described above, the downlink path 16 from network 10 to device 2 is connected when an output signal from device 2 to network 10 is detected, and disconnected when the output signal is no longer detected. Therefore, when device 2 initiates communication with network 10, the downlink path 16 can be connected, and when communication ends, the downlink path 16 can be disconnected. Thus, compared to a case where the downlink path 16 is always connected, the opportunity for attacks from network 10 against device 2 can be reduced, and the security of device 2 can be improved. Therefore, unlike a case where a configuration is incorporated into device 2 to switch the downlink path 16 from disconnected to connected prior to the transmission of an output signal, the security of device 2 can be improved without making any changes to the existing device 2, and the security of device 2 can be continuously improved even if the configuration of device 2 is changed due to updates, etc. Furthermore, unlike the case where the downlink path 16 is switched from a disconnected state to a connected state prior to the transmission of the output signal and is externally connected to device 2 via a USB cable, this configuration improves the security of device 2 even when device 2 does not have a USB terminal, and prevents the placement of device 2, repeater 3, and power supply 4 from being restricted by the maximum length specified for USB cables (for example, 5m).

[0035] Furthermore, by controlling the power supply to the repeater 3, which relays signals from network 10 to device 2, the connection and disconnection states of the downlink path 16 are switched, ensuring reliable switching between connection and disconnection states. In addition, the power consumption of the repeater 3 can be reduced compared to when power is supplied to the repeater 3 continuously.

[0036] Furthermore, since the link-up unit 51 maintains the device 2 in a state where it can transmit, the output signal can be reliably output from the device 2.

[0037] Furthermore, the portion of the uplink path 17 between the link-up unit 51 and the network 10 is either connected or disconnected, along with the downlink path 16. Therefore, the security of the device 2 can be further improved compared to the case where the uplink path 17 is maintained in a connected state. In addition, since the uplink path 17 is disconnected between the link-up unit 51 and the network 10, the uplink path 17 is maintained in a connected state between the device 2 and the link-up unit 51, ensuring that output signals can be reliably output from the device 2.

[0038] Furthermore, the downlink path 16 is disconnected when the output signal is no longer detected and the elapsed time since the output signal was detected exceeds a reference time. Therefore, it is possible to prevent the downlink path 16 from being disconnected when the output signal continues to be output intermittently.

[0039] Furthermore, since the trigger signal output from the link-up unit 51 in response to receiving the output signal from device 2 is detected as the output signal from device 2 to network 10, the output signal can be reliably detected.

[0040] (operation) Figure 2 shows the operation of the communication control device 5. The communication control device 5 controls communication between the device 2 and the network 10 by performing the processing in steps S11 to S21. The operation shown in this figure may start when the communication control device 5 is activated, and at the start, the device 2 may be in a state where it can output a signal via the link-up unit 51. Also, the power supply 4 may be in the off state, and as a result, the downlink path 16 and the portion of the uplink path 17 between the link-up unit 51 and the network 10 may be disconnected.

[0041] In step S11, the detection unit 52 detects the output signal that is output from the device 2 to the network 10.

[0042] In step S13, the switching unit 54 switches the downlink path 16 from a disconnected state to a connected state. In this embodiment, as an example, the switching unit 54 may operate the repeater 3 by switching the power switch 41 on the power supply 4 from the off state to the on state. As a result, the downlink path 16 is connected in response to the detection of an output signal, enabling communication from the network 10 to the device 2. In addition, the portion of the uplink path 17 between the link-up unit 51 and the network 10 is connected, enabling communication from the device 2 to the network 10.

[0043] In step S15, the timing unit 53 starts measuring the elapsed time since the output signal was detected. The timing unit 53 may reset the elapsed time measured so far and start a new measurement each time the process in step S15 is performed.

[0044] In step S17, the detection unit 52 determines whether or not an output signal is further detected from device 2 to network 10. The detection unit 52 may attempt to detect the output signal and determine whether or not an output signal is detected. Here, the detected output signal may be an ACK (acknowledgement) signal returned from device 2 in response to a signal transmitted from network 10 to device 2. As a result, while multiple packets of signals are being transmitted from network 10 to device 2, the detection unit 52 may detect an output signal from device 2.

[0045] If it is determined that an output signal has been detected (step S17; Yes), the process may proceed to step S15. If it is determined that no further output signals have been detected (step S17; No), the process may proceed to step S19.

[0046] In step S19, the switching unit 54 determines whether the elapsed time has reached the reference time. If it is determined that the elapsed time has not reached the reference time (step S19; No), the process may proceed to step S17. If it is determined that the elapsed time has reached the reference time (step S19; Yes), the process may proceed to step S21.

[0047] In step S21, the switching unit 54 switches the downlink path 16 from a connected state to a disconnected state. In this embodiment, as an example, the switching unit 54 may stop the repeater 3 by switching the power switch 41 on the power supply 4 from the ON state to the OFF state. As a result, the downlink path 16 is disconnected in accordance with the fact that no output signal is detected, and communication from the network 10 to the device 2 becomes impossible. Also, the portion of the uplink path 17 between the link-up unit 51 and the network 10 is disconnected, and communication from the device 2 to the network 10 becomes impossible. However, the device 2 may be kept in a state where it can output a signal by the link-up unit 51. After the processing of step S21 is completed, the process may proceed to step S11 described above.

[0048] In the above embodiment, the switching unit 54 was described as switching the downlink path 16 to a connected or disconnected state by switching the power switch 41 of the power supply 4 on or off. However, the switching may also be performed by switching the on or off switch provided in the power supply path between the power supply 4 and the repeater 3.

[0049] (Variation (1)) Figure 3 shows System 1A according to Modification (1). In System 1A according to this modification, components that are substantially the same as those in System 1 shown in Figure 1 are given the same reference numerals, and their explanations are omitted.

[0050] The modified system 1A includes a communication control device 5A. The communication control device 5A has an on / off switch 55A and a switching unit 54A.

[0051] ((On / off switch 55A)) The on / off switch 55A is provided in the downlink path 16 and opens and closes the downlink path 16. The on / off switch 55A may be provided in the downlink path 16 on the side of the network 10 that is closer to the link-up unit 51. In this embodiment, for example, it may be provided between the link-up unit 51 and the repeater 3. The on / off switch 55A may be a mechanical switch, a semiconductor switch, or a combination of these.

[0052] ((Switching section 54A)) The switching unit 54A connects the downlink path 16 when the detection unit 52 detects an output signal, and disconnects the downlink path 16 when the detection unit 52 no longer detects an output signal. The switching unit 54A may also disconnect the downlink path 16 when the detection unit 52 no longer detects an output signal and the elapsed time exceeds a reference time. The switching unit 54A may perform the switching based on the detection signal supplied from the detection unit 52. In this modified example, the switching unit 54A switches between the connected state and the disconnected state by controlling the on / off switch 55A.

[0053] According to the communication control device 5A described above, the connection state and disconnection state of the downlink path 16 are switched by controlling the on / off switch 55A provided in the downlink path 16, so that the switching between the connection state and the disconnection state can be performed reliably.

[0054] Furthermore, unlike the case where power supply to the repeater 3 located in the communication path 15 is controlled, the uplink path 17 can be maintained in a connected state, thus ensuring that output signals from the device 2 are reliably transmitted to the network 10.

[0055] In the above modified example (1), the switching switch 55A was described as being provided in the downlink path 16, but it may also be provided in the communication path 15 on the side of the network 10 rather than the link-up unit 51. In this case, the switching unit 54A may connect or disconnect the portion of the uplink path 17 between the link-up unit 51 and the network 10, together with the downlink path 16.

[0056] (Variation (2)) Figure 4 shows System 1B according to Modification (2). In System 1B according to this modification, components that are substantially the same as those in Systems 1 and 1A shown in Figures 1 and 3 are given the same reference numerals, and their explanations are omitted.

[0057] The device 2 of system 1B and the network 10 are connected by a wired communication path 15B. In the communication path 15B, the downlink path 16 and the uplink path 17 may be common. A communication control device 5B is provided in the communication path 15B. The communication control device 5B has a switching unit 54B.

[0058] ((Switching section 54B)) The switching unit 54B connects the communication path 15B when the detection unit 52 detects an output signal from the device 2 to the network 10, and disconnects the communication path 15B when the signal is no longer detected. The switching unit 54B may also disconnect the communication path 15B when the detection unit 52 no longer detects a signal and the elapsed time exceeds a reference time. The switching unit 54B may perform the switching based on the detection signal supplied from the detection unit 52.

[0059] The switching unit 54B may set the portion of the communication path 15B between the link-up unit 51 and the network 10 to either a connected or disconnected state. In this modified example, the switching unit 54B switches between a connected and disconnected state by controlling the on / off switch 55A located on the network 10 side of the communication path 15B, which is on the side of the link-up unit 51, in the same manner as the switching unit 54A described above. Alternatively, the communication path 15B may be switched between a connected or disconnected state by switching the power switch 41 in the power supply 4 on or off, in the same manner as the switching unit 54 described above.

[0060] According to the communication control device 5B described above, even if the downlink path 16 and uplink path 17 share a common communication path 15B, the opportunity for attacks on device 2 can be reduced and the security of device 2 can be improved.

[0061] (Second Embodiment) Figure 5 shows system 1C according to this embodiment. In system 1C according to this embodiment, components that are substantially the same as those in systems 1, 1A, and 1B shown in Figures 1, 4, and 5 are given the same reference numerals, and their descriptions are omitted.

[0062] System 1C comprises device 6C. Device 6C has equipment 2 connected to network 10 and a communication control device 5. Device 6C may be an industrial, server, or office PC with communication control functions via the communication control device 5, or it may be another type of communication-capable equipment (for example, measuring instruments, analyzers, control equipment, POS registers, digital signage, etc.). Device 6C may have any of the communication control devices 5A, 5B, or 5C instead of the communication control device 5.

[0063] As described above, the device 6C has a communication control device 5, which reduces the opportunity for attacks on the device 6C from the network 10 and improves the security of the device 6C.

[0064] (Third embodiment) Figure 6 shows system 1D according to this embodiment. In system 1D according to this embodiment, components that are substantially the same as those in systems 1, 1A, 1B, and 1C shown in Figures 1, 4, 5, and 6 are given the same reference numerals, and their descriptions are omitted.

[0065] System 1D includes a network device 7D. The network device 7D includes a repeater 3 installed between the equipment 2 and the network 10, and a communication control device 5. The network device 7D may further include a power supply 4. The network device 7D may be a network device having a communication control function by the communication control device 5. The network device 7D may have any of the communication control devices 5A, 5B, or 5C instead of the communication control device 5.

[0066] According to the network device 7D described above, since it has a communication control device 5, the opportunity for attacks on device 2 from the network 10 can be reduced and the security of device 2 can be improved.

[0067] (Other variations) In the above embodiments and modifications, the detection unit 52 was described as detecting a trigger signal output by the link-up unit 51 in response to receiving an output signal from the device 2 as an output signal. However, it may also be provided on the communication paths 15 and 15B and relay signals from the device 2 to the network 10 and signals from the network 10 to the device 2, analyzing each signal to detect the output signal from the device 2 to the network 10. As an example, the detection unit 52 may detect data on the MII (Media Independent Interface) as an output signal in the same manner as the link-up unit 51.

[0068] Furthermore, although communication paths 15 and 15B have been described as wired communication paths, communication paths 15 and 15B may also include wireless communication paths in part. For example, a wireless communication path may be included between the communication control devices 5, 5A, and 5B and the repeater 3. In this case, for example, the repeater 3 may be a Wi-Fi® router, and the communication control devices 5, 5A, and 5B may be Wi-Fi® adapters that communicate wirelessly with the repeater 3.

[0069] Furthermore, although it has been explained that a single device 2 is connected to the communication control devices 5, 5A, 5B, 5D in systems 1, 1A, 1B, 1D, multiple devices 2 may be connected. In this case, the communication control devices 5, 5A, 5B, 5D and the network 10 may be connected by common communication paths 15, 15B among the multiple devices 2. Also, the switching units 54, 54A may connect the downlink path 16 of the common communication paths 15, 15B in response to the detection of an output signal from any of the devices 2 to the network 10, and may disconnect the downlink path 16 of the common communication paths 15, 15B in response to the detection of no output signals from any of the devices 2.

[0070] Furthermore, although the switching units 54, 54A, and 54B were described as disconnecting the downlink path 16 when the output signal from device 2 to network 10 is no longer detected, they may also be disconnected when the signal from network 10 to device 2 is no longer detected. In this case, when a signal is output from network 10 to device 2 in response to the output signal from device 2 to network 10, the downlink path 16 will be disconnected only after that signal has disappeared, thus preventing communication to device 2 from being terminated prematurely.

[0071] Furthermore, although the communication control devices 5, 5A, and 5B have been described as having a link-up unit 51 and a timing unit 53, they do not necessarily have to have either of these. If the communication control devices 5, 5A, and 5B do not have a link-up unit 51, the device 2 may be maintained in a state where it can transmit signals to the network 10 without the link-up unit 51. If the communication control devices 5, 5A, and 5B do not have a timing unit 53, the switching units 54 and 54A may disconnect the downlink path 16 in accordance with the detection unit 52 no longer detecting an output signal.

[0072] Various embodiments of the present invention may be described with reference to flowcharts and block diagrams, where a block may represent (1) a stage in a process in which an operation is performed or (2) a section of a device having the role of performing the operation. Specific stages and sections may be implemented by dedicated circuits, programmable circuits supplied with computer-readable instructions stored on a computer-readable medium, and / or processors supplied with computer-readable instructions stored on a computer-readable medium. Dedicated circuits may include digital and / or analog hardware circuits, and may include integrated circuits (ICs) and / or discrete circuits. Programmable circuits may include reconfigurable hardware circuits, including logical AND, logical OR, logical XOR, logical NAND, logical NOR, and other logic operations, flip-flops, registers, memory elements such as field-programmable gate arrays (FPGAs), programmable logic arrays (PLAs), etc.

[0073] Computer-readable media may include any tangible device capable of storing instructions to be executed by a suitable device, and as a result, computer-readable media having instructions stored therein will comprise a product containing instructions that can be executed to create means for performing operations specified in a flowchart or block diagram. Examples of computer-readable media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disk read-only memory (CD-ROM), digital multipurpose disc (DVD), Blu-ray® disc, memory stick, integrated circuit card, etc.

[0074] Computer-readable instructions may include assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, Java®, C++, and traditional procedural programming languages ​​such as the C programming language or similar programming languages.

[0075] Computer-readable instructions are provided locally or via a wide area network (WAN) such as a local area network (LAN) or the internet to the processor or programmable circuit of a programmable data processing device such as a computer, and may be executed to create means for performing operations specified in a flowchart or block diagram. Here, the computer may be a PC (personal computer), tablet computer, smartphone, workstation, server computer, general-purpose computer, or special-purpose computer, and may also be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system and is a computer in a broad sense. In a distributed computing system, multiple computers execute a program collectively by each computer executing a part of the program and passing data during program execution between computers as needed.

[0076] Examples of processors include computer processors, central processing units (CPUs), processing units, microprocessors, digital signal processors, controllers, and microcontrollers. A computer may have one or more processors. In a multiprocessor system with multiple processors, each processor executes a portion of the program, and the processors collectively execute the program by passing program execution data between them as needed. For example, in the execution of multitasking, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at each time slice. In this case, which part of a program each processor executes changes dynamically. Which part of a program each of the multiple processors executes may also be statically determined by multiprocessor-aware programming.

[0077] Figure 7 shows an example of a computer 1200 in which multiple aspects of the present invention may be embodied in whole or in part. A program installed on the computer 1200 can cause the computer 1200 to function as an operation or one or more sections of an apparatus according to an embodiment of the present invention, or to execute such operation or one or more sections, and / or to cause the computer 1200 to execute a process or a stage of such process according to an embodiment of the present invention. Such a program may be executed by the CPU 1212 to cause the computer 1200 to perform a particular operation associated with some or all of the blocks in the flowcharts and block diagrams described herein.

[0078] The computer 1200 according to this embodiment includes a CPU 1212, RAM 1214, a graphics controller 1216, and a display device 1218, which are interconnected by a host controller 1210. The computer 1200 also includes input / output units such as a communication interface 1222, a storage device 1224 such as a hard disk drive, a DVD-ROM drive 1226, and an IC card drive, which are connected to the host controller 1210 via an input / output controller 1220. The computer also includes legacy input / output units such as a ROM 1230 and a keyboard 1242, which are connected to the input / output controller 1220 via an input / output chip 1240.

[0079] The CPU 1212 operates according to programs stored in the ROM 1230 and RAM 1214, thereby controlling each unit. The graphics controller 1216 acquires image data generated by the CPU 1212 from a frame buffer provided in RAM 1214 or from itself, and displays the image data on the display device 1218.

[0080] The communication interface 1222 communicates with other electronic devices via a network. The storage device 1224 stores programs and data used by the CPU 1212 in the computer 1200. The DVD-ROM drive 1226 reads programs or data from the DVD-ROM 1227 and provides them to the storage device 1224 via the RAM 1214. The IC card drive reads programs and data from the IC card and / or writes programs and data to the IC card.

[0081] The ROM 1230 stores boot programs and / or programs that depend on the computer 1200's hardware, which are executed by the computer 1200 when activated. The input / output chip 1240 may also connect various input / output units to the input / output controller 1220 via a parallel port, serial port, keyboard port, mouse port, etc.

[0082] The program is provided on a computer-readable medium such as a DVD-ROM 1227 or an IC card. The program is read from the computer-readable medium and installed on a storage device 1224, RAM 1214, or ROM 1230, which are also examples of computer-readable medium, and executed by the CPU 1212. The information processing described within these programs is read by the computer 1200, resulting in coordination between the program and the various types of hardware resources described above. The apparatus or method may be configured to realize the manipulation or processing of information in accordance with the use of the computer 1200.

[0083] For example, when communication is performed between a computer 1200 and an external device, the CPU 1212 may execute a communication program loaded into RAM 1214 and, based on the processing described in the communication program, instruct the communication interface 1222 to perform communication processing. Under the control of the CPU 1212, the communication interface 1222 reads transmission data stored in a transmission buffer processing area provided in a recording medium such as RAM 1214, storage device 1224, DVD-ROM 1227, or IC card, transmits the read transmission data to the network, or writes received data received from the network to a receive buffer processing area provided on the recording medium.

[0084] Furthermore, the CPU 1212 may read all or necessary parts of a file or database stored on an external storage medium such as the memory device 1224, DVD-ROM drive 1226 (DVD-ROM 1227), or IC card into the RAM 1214, and perform various types of processing on the data in the RAM 1214. The CPU 1212 then writes the processed data back to the external storage medium.

[0085] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and subjected to information processing. The CPU 1212 may perform various types of processing on the data read from RAM 1214, including various types of operations, information processing, conditional judgments, conditional branching, unconditional branching, information retrieval / replacement, etc., as described throughout this disclosure and specified by the program instruction sequence, and write the results back to RAM 1214. The CPU 1212 may also retrieve information in files, databases, etc., within the recording medium. For example, if multiple entries are stored in the recording medium, each having an attribute value of a first attribute associated with an attribute value of a second attribute, the CPU 1212 may search among the multiple entries for an entry that matches the condition for which the attribute value of the first attribute is specified, read the attribute value of the second attribute stored in that entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0086] The programs or software modules described above may be stored on or near computer 1200 on a computer-readable medium. Alternatively, recording media such as hard disks or RAM provided within a server system connected to a dedicated communication network or the Internet can be used as computer-readable media, thereby providing programs to computer 1200 via the network.

[0087] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention.

[0088] It should be noted that the execution order of operations, procedures, steps, and stages in the apparatus, systems, programs, and methods shown in the claims, specifications, and drawings is not explicitly stated as "before," "prior to," etc., and that these can be implemented in any order unless the output of a previous process is used in a later process. Even if the operation flow in the claims, specifications, and drawings is described using phrases such as "first," "next," etc. for convenience, it does not mean that it is essential to perform the operations in that order. [Explanation of Symbols]

[0089] 1 System 2 equipment 3 Repeater 4 Power supply 5. Communication control device 6 equipment 7 Network Devices 10 Networks 15. Communication Path 16 Downlink Route 17 Uplink Routes 41 Power switch 51 Link-up section 52 Detection unit 53 Timing section 54 Switching section 55 Open / Close Switch 1200 Computers 1210 Host Controller 1212 CPU 1214 RAM 1216 Graphics Controller 1218 Display Devices 1220 Input / Output Controller 1222 Communication Interface 1224 Storage device 1226 DVD-ROM drive 1227 DVD-ROM 1230 ROM 1240 input / output chip 1242 keyboard

Claims

1. A detection unit that detects the output signal that is sent from the device to the network, A switching unit that connects the first communication path from the network to the device when the detection unit detects an output signal, and disconnects the first communication path when the detection unit no longer detects an output signal. A communication control device equipped with the following features.

2. The communication control device according to claim 1, wherein the switching unit is provided in the first communication path and switches between a connected state and a disconnected state by controlling the power supply to a repeater that relays signals from the network to the device.

3. The first communication path is provided with a switch for opening and closing the first communication path, The communication control device according to claim 1, wherein the switching unit switches between a connected state and a disconnected state by controlling the switch.

4. The communication control device according to claim 1, further comprising a link-up unit provided in a second communication path from the device to the network, for maintaining the device in a state where it can transmit.

5. The link-up unit, upon receiving an output signal from the device, outputs the output signal to the network and also outputs a trigger signal to the detection unit. The communication control device according to claim 4, wherein the detection unit detects the trigger signal as the output signal.

6. The communication control device according to claim 4, wherein the switching unit sets the portion of the second communication path between the link-up unit and the network to either a connected state or a disconnected state together with the first communication path.

7. The communication control device according to claim 6, wherein the first communication path and the second communication path are a common communication path.

8. The system further includes a timing unit that measures the elapsed time since the output signal was detected by the detection unit, The communication control device according to claim 1, wherein the switching unit disconnects the first communication path when the output signal is no longer detected by the detection unit and the elapsed time exceeds the reference time.

9. A communication control device according to any one of claims 1 to 8, The device connected to the aforementioned network, A device equipped with the following features.

10. A relay device is provided between the device and the network and relays signals between the device and the network, A communication control device according to any one of claims 1 to 8, A network device equipped with the following features.

11. A detection stage for detecting the output signal that is sent from the device to the network, A switching step in which, in response to the detection of an output signal in the detection step, the first communication path from the network to the device is connected, and in response to the detection of no longer being detected in the detection step, the first communication path is disconnected. A method for providing this.

12. By being executed by a computer, the computer will A detection unit that detects the output signal that is sent from the device to the network, A switching unit connects the first communication path from the network to the device when the detection unit detects an output signal, and disconnects the first communication path when the detection unit no longer detects an output signal. A program that makes it function as such.

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