Network device and network system

Abstract

To supply or receive power without delay even when power supply is abnormal, in a network device.SOLUTION: In a network device, a plurality of network devices are connected by a network cable. The network device comprises: a power circuit which takes in external power; a power supply unit which supplies output of the power circuit into the device as a power supply in the device; a power supply abnormality detection unit which detects abnormality of the output of the power circuit; a terminal unit to which the network cable is connected; a power receiving circuit which receives electric power from other network devices via the terminal unit and outputs the electric power to the power supply unit; and a power feeding circuit which supplies the electric power from the power supply unit to other network devices via the terminal unit. When the power supply abnormality detection unit detects abnormality in the output of the power circuit, the power supply unit switches the power supply in the device to the electric power received from the power receiving circuit instead of the output of the power circuit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present application relates to a network device and a network system. [Background technology]

[0002] In network devices such as power plants, multiple power sources are used to stabilize operation in the event of a power failure or abnormality, and typically, a method is used to maintain stability by preparing multiple power supply devices. However, preparing multiple conventional power sources inevitably results in larger equipment and higher costs. On the other hand, network devices that communicate using Ethernet cables (Ethernet is a registered trademark) can use Power over Ethernet (hereinafter referred to as PoE) as a means of power supply, making it possible to supply power without impairing network functions. One possible method for supplying power to network devices is to use PoE. Patent Document 1 discloses a technique for preventing incorrect cable connections and for mutual power supply between network devices. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-40604 A Summary of the Invention [Problem to be solved by the invention]

[0004] According to Patent Document 1, the network device detects whether a first port of the network device is connected to a power supply device, and if the detection result shows that the first port is connected to the power supply device, the network device maintains the powered state, or changes the state of the first port to a powered state and locks the first port as a power sink port. Also, if the detection result shows that the first port is not connected to the power supply device and the network device has a power source for supplying power, the network device switches the state of the first port to a powered state.

[0005] Although the device can switch between transmitting and receiving power using a judgment section inside the device, the mode is fixed depending on the judgment result. Therefore, there was an issue that the device could not receive power when there was an abnormality in the power supply. The present application has been made to solve the above-mentioned problems, and aims to obtain a device that can inexpensively multiplex power sources by utilizing PoE, can easily supply power to other devices and receive power from other devices, and can supply or receive power without delay even in the event of an abnormality, thereby not impairing network functions. [Means for solving the problem]

[0006] The network device according to the present application is a network device to which a plurality of network devices are connected by network cables, and includes a power supply circuit that takes in external power, a power supply unit that supplies the output of the power supply circuit to the device as an internal power source, a power abnormality detection unit that detects an abnormality in the output of the power supply circuit, a terminal unit to which the network cable is connected, a power receiving circuit that receives power from another network device via the terminal unit and outputs it to the power supply unit, and a power supply circuit that supplies power from the power supply unit to the other network device via the terminal unit. When the power abnormality detection unit detects an abnormality in the output of the power supply circuit, teeth, The power receiving circuit is used in place of the output of the power supply circuit. Other network devices Switch the power supply in the device to the power received from At the same time, the power supply circuit stops supplying power to the other network devices. It is something. Effect of the Invention

[0007] By having the power receiving circuit and the power supplying circuit, it becomes possible to exchange power with other network devices connected by the network cable. This makes it possible to realize multiplexing of power sources at low cost, and to easily supply power to other devices and receive power from other devices to the device itself. In the event of a power abnormality in the device itself, it is possible to obtain a device that does not lose its network functions by receiving power without delay via the network cable. [Brief description of the drawings]

[0008] [Figure 1] 1 is a configuration diagram showing a network device according to a first embodiment. [Diagram 2] 2 is a configuration diagram showing a control unit of the network device according to the first embodiment. FIG. [Diagram 3] 4 is a flowchart showing an operation of the network device according to the first embodiment. [Figure 4A] 1 is a schematic diagram showing power supply multiplexing between network devices according to a first embodiment; [Figure 4B] 1 is a schematic diagram showing power supply multiplexing between network devices according to a first embodiment; [Figure 4C] 1 is a schematic diagram showing power supply multiplexing between network devices according to a first embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Embodiment 1 A first embodiment of the present application will be described with reference to FIG. 1. FIG. 1 is a diagram showing the configuration of a network device 1. In FIG. 1, a power supply circuit 2 receives power from an external power source such as a commercial power source, and outputs power to a power supply unit 3 as an internal power source of the device. A control unit 4 controls each unit in the device and performs data processing between the power supply circuit 3 and a data transmission / reception circuit 5. A first terminal unit 8 and a second terminal unit 9 are portions to which a network cable from another network device is connected, and correspond to a connector of an Ethernet cable that realizes PoE. The first terminal unit 8 and the second terminal unit respectively have a power receiving terminal 6a, a power supply terminal 7a, and a data signal terminal 5a, and the power receiving terminal 6a is connected to the power receiving circuit 6 and the power supply terminal 7a is connected to the power supply circuit 7. In addition, a diode 10 for preventing sneak current is provided in the power receiving circuit 6. The output of the power receiving circuit 6 and the input of the power supply circuit 7 are connected to the power supply unit 3. The data signal terminal 5a is connected to the data transmission / reception circuit 5. The power supply abnormality detection unit 11 works in conjunction with the control unit 4 to detect abnormalities in the output of the power supply circuit 2, and when an abnormality is detected, the control unit 4 switches the power supply within the device to received power from the power receiving circuit 6 via the power supply unit 3. In addition, the control unit 4 stops power supply from the power supply circuit 7 via the power supply unit 3 or the power supply circuit 7.

[0010] As shown in FIG. 2, the control unit 4 is composed of a processor 101 and a storage device 102. Although not shown, the storage device includes a volatile storage device such as a random access memory and a non-volatile auxiliary storage device such as a flash memory. Instead of the flash memory, a hard disk auxiliary storage device may be included. The processor 101 executes a program input from the storage device 102 and performs part or all of the operations of each unit in the device described in FIG. 1 and the flowchart described in FIG. 3. In this case, the program is input from the auxiliary storage device to the processor 101 via the volatile storage device. The processor 101 may output data such as input / output signals, intermediate values ​​of calculations, and calculation results to the volatile storage device of the storage device 102, or may store data in the auxiliary storage device via the volatile storage device. In addition to the processor 101 and the storage device 102, a logic circuit and an analog circuit may be used in combination.

[0011] Next, the operation of each unit will be described with reference to the flowchart shown in Fig. 3. In Fig. 3, the network device 1 starts up in step S0. At the time of startup, the output of the power supply circuit 2 is used as the internal power source of the device. In addition, data transmission and reception with other network devices, as well as receiving power from the power receiving circuit 6 and supplying power to the power supply circuit 7, begin via the network cable.

[0012] In step S1, the power supply abnormality detection unit 11 monitors whether the output of the power supply circuit 2 is normal or abnormal. A power supply abnormality is detected by detecting the output power of the power supply circuit 2 and checking its fluctuations, and judging it to be abnormal, for example, if there is a sudden change in state, or if the state deviates from the normal power range for a certain period of time. This judgment may be made by the power supply abnormality detection unit 11 alone, or the power supply abnormality detection unit 11 may only detect the output power, and the control unit 4 may judge the abnormality from the fluctuations in the output power. In this way, by making a judgment based on the output power of the power supply circuit 2, it is possible to detect both an abnormality in the external power supply and an abnormality in the power supply circuit 2 within the device.

[0013] In step S2, the control unit 4 judges whether the power supply is normal or abnormal, and if it is judged to be normal, in step S3, as usual, the power supply unit 3 maintains the power supply within the device with the output of the power supply circuit 2. Also, in step S4, the power supply unit 3 continues the process of taking in received power from other network devices through the power receiving circuit 6, and outputting the power to be fed to other network devices through the power feeding circuit 7 with the internal power supply from the output of the power supply circuit 2.

[0014] If the control unit 4 determines in step S2 that the output of the power supply circuit 2 is abnormal, then in step S5 the power supply unit 3 switches from the internal power source provided by the output of the power supply circuit 2 to received power from another network device via the power receiving circuit 6. Also, in step S6 the power supply unit 3 stops the supply of power to the other network device via the power feeding circuit 7. By operating in this manner, it is possible to reduce power consumption within the device due to power feeding. The processing of the power supply unit 3 in steps S3 to S6 may be performed by the power supply unit 3 alone or in conjunction with the control unit 4.

[0015] Finally, the process proceeds from step S4 or step S6 to step S7, where the control unit 4 continues data transmission / reception processing with the data transmission / reception circuit 5 as the network device 1. Also, the process returns to step S1 to repeat the same processing. In this way, even if an abnormality occurs in the output of the power supply circuit 2, the data transmission / reception processing operation as a network device can be continued using the power received via the network.

[0016] 4A to 4C explain the exchange of power supply and reception with other network devices, using three network devices as examples. During normal operation, the three network devices 1a to 1c receive and supply power from each other via network cables 21 and 22, as shown in FIG. 4A. For example, as shown in FIG. 4B, if an abnormality occurs in the power supply of the network device 1a located at the left end, the network device 1a can continue to operate by receiving power from the first terminal 8b of the network device 1b at the second terminal 9a of the network device 1a via the network cable 21.

[0017] 4C, when a power supply abnormality occurs in network device 1b located between three network devices 1a to 1c, network device 1a can receive power from a second terminal 9a of network device 1a and a first terminal 8c of network device 1c to a first terminal 8b and a second terminal 9b of network device 1b via network cables 21 and 22. Network device 1b can receive power from network devices 1a and 1c, and can continue to operate using one or both of these received powers.

[0018] By combining peripheral network devices in this way, power can be supplied from adjacent network devices to each other, and the network function of a network device in which a power supply abnormality has occurred can be maintained without being impaired, thus achieving power multiplexing for the entire network system. Furthermore, in this embodiment, the network devices are connected in a row in a daisy chain, but power multiplexing can be achieved in the same way by connecting them in a ring shape.

[0019] Generally, PoE is used only for power supply or power reception, using unused port pairs in one Ethernet cable or data pairs of a network with superimposed power. Alternatively, both may be used simultaneously to improve the power supply. In the present application, these pairs are used in one Ethernet cable by dividing them into a power receiving terminal 6a and a power supply terminal 7a. This makes it unnecessary to judge whether power is being received or supplied, and eliminates the need to switch between power receiving and power supply. This makes it possible to avoid incorrect connection of the power receiving and power supply cables.

[0020] In the present application, the Ethernet mechanism using PoE has been described, but the present invention is not limited to PoE and similar effects can be achieved with any network device having a similar configuration.

[0021] Although various exemplary embodiments and examples are described in this application, various features, aspects, and functions described in one or more embodiments are not limited to the application of a specific embodiment, but can be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are expected within the scope of the technology disclosed in this specification. For example, the following are included: when at least one component is modified, added, or omitted, and further, when at least one component is extracted and combined with a component of another embodiment. [Explanation of symbols]

[0022] 1, 1a, 1b, 1c network device, 2 power supply circuit, 3 power supply unit, 4 control unit, 5 data transmission / reception circuit, 5a data signal terminal, 6 power receiving circuit, 6a power receiving terminal, 7 power supply circuit, 7a power supply terminal, 8, 8a, 8b, 8c first terminal unit, 9, 9a, 9b, 9c second terminal unit, 10 diode, 11 power supply abnormality detection unit, 21, 22 network cable, 101 processor, 102 storage device.

Claims

1. A network device in which a plurality of network devices are connected by a network cable, A power supply circuit that takes in an external power source; a power supply unit that supplies an output of the power supply circuit to an inside of the device as an internal power source of the device; a power supply abnormality detection unit that detects an abnormality in the output of the power supply circuit; a terminal portion to which the network cable is connected; a power receiving circuit that receives power from another of the network devices via the terminal unit and outputs the power to the power supply unit; a power supply circuit that supplies power from the power supply unit to the other network device via the terminal unit, A network device characterized in that, when the power supply abnormality detection unit detects an abnormality in the output of the power supply circuit, the power supply unit switches the power supply within the device to power received from another of the network devices via the power receiving circuit instead of the output of the power supply circuit, and stops power supply to the other of the network devices via the power supply circuit.

2. the terminal unit includes a first terminal unit connected to a first network device and a second terminal unit connected to a second network device; the first terminal portion and the second terminal portion each have a power receiving terminal and a power supply terminal, The network device according to claim 1, characterized in that when the power supply abnormality detection unit detects an abnormality in the output of the power supply circuit, the power supply unit switches the power supply within the device to power received from both or either of the power receiving terminal of the first terminal unit and the power receiving terminal of the second terminal unit, instead of the output of the power supply circuit.

3. 3. A network system comprising a plurality of network devices according to claim 1 or 2 connected together by said network cable.

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