Communication equipment, abnormality detection method, and abnormality detection program

Abstract

To provide communication equipment which can detect abnormality occurring in the equipment, an abnormality detection method, and an abnormality detection program.SOLUTION: Communication equipment is provided, comprising: a communication portion performing communication with external equipment; a voltage monitoring portion monitoring a power source voltage and outputting a voltage drop signal if the power source voltage becomes less than a threshold value; a control portion transmitting power off notification to the external equipment when receiving the voltage drop signal from the voltage monitoring portion; and a storage portion storing notification information indicating that power off notification has been transmitted and power off information indicating that power has been turned off, the control portion detects failure of the voltage monitoring portion based on the notification information and the power off information, at start up.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a communication device, an abnormality detection method for the communication device, and an abnormality detection program. [Background technology]

[0002] Conventionally, systems such as EPON (Ethernet Passive Optical Network) that include an OLT (Optical Line Terminal) as a central office optical terminal device and an ONU (Optical Network Unit) as a subscriber optical terminal device are known. As a method for detecting an abnormality in such a system, a method such as CRC (Circular Redundancy Check) is known in which the ONU checks each part of its own device for the normality of the frame data of the main signal when a value set in the ONU is not reflected in the device.

[0003] Patent Document 1 also discloses that when an abnormality such as a power OFF occurs in the ONU due to a power outage, the ONU transmits a notification to the OLT. In detail, Patent Document 1 discloses that when the power supply voltage in the ONU drops below the normal value and reaches a first threshold, the communication unit of the ONU transmits a DyingGasp notification to the OLT. This enables the OLT to determine whether the interruption of communication with the ONU is due to the ONU being power OFF or due to some other abnormality. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-8273 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the ONU of Patent Document 1, if the voltage monitoring unit that monitors the drop in the power supply voltage breaks down, the OLT will not be able to send a DyingGasp notification even if the power supply voltage drops. In this case, it will take time for the OLT to identify the cause of the communication cutoff with the ONU.

[0006] The present invention has been made in light of the above-mentioned problems, and aims to provide a communication device, an abnormality detection method, and an abnormality detection program capable of detecting abnormalities within the device itself. [Means for solving the problem]

[0007] The communication device of the present invention comprises a communication unit that communicates with an external device, a voltage monitoring unit that monitors the power supply voltage and outputs a voltage drop signal when the power supply voltage falls below a threshold value, a control unit that sends a power off notification to the external device when a voltage drop signal is received from the voltage monitoring unit, and a memory unit that stores notification information indicating that the power off notification has been sent and power off information indicating that the power has been turned off, and the control unit detects a failure in the voltage monitoring unit based on the notification information and the power off information at the time of startup.

[0008] An anomaly detection method according to the present invention is an anomaly detection method for a communication device, and includes the steps of: monitoring a power supply voltage by a voltage monitoring unit, and outputting a voltage drop signal when the power supply voltage falls below a threshold value, transmitting a power OFF notification to an external device by a control unit when the voltage drop signal is received from the voltage monitoring unit, storing notification information indicating that the power OFF notification has been transmitted to the external device in a storage unit when the power OFF notification has been transmitted to the external device, and detecting a failure in the voltage monitoring unit based on the notification information and power OFF information indicating that the power has been turned off at startup by the control unit.An anomaly detection program according to the present invention is a program for causing a processor of the communication device to execute the anomaly detection method. Effect of the Invention

[0009] According to the communication device, abnormality detection method, and abnormality detection program of the present invention, at the time of startup, a failure in the voltage monitoring unit is detected based on notification information and power-off information, thereby making it possible to detect an abnormality within the device itself. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a communication system according to a first embodiment. [Diagram 2] 1 is a diagram for explaining the flow of operations when the power supply of an ONU is turned off in the first embodiment. [Diagram 3] 5 is a flowchart showing a flow of an abnormality detection process in an ONU according to the first embodiment. [Figure 4] FIG. 1 is a diagram illustrating an operation flow when an ONU is powered off in a communication system according to the conventional technology. [Diagram 5] 11 is a flowchart showing the flow of an abnormality detection process in an ONU according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Embodiment 1 Fig. 1 is a schematic configuration diagram of a communication system 100 according to a first embodiment. The communication system 100 is, for example, an EPON system, and includes an ONU1 which is a subscriber optical terminal device, an OLT2 which is a central office optical terminal device, and an optical splitter 3. The ONU1 and the OLT2 are connected to an optical line via the optical splitter 3, and perform wired communication. Although only one ONU1 is shown in Fig. 1, a plurality of ONU1 are connected to the OLT2 via the optical splitter 3.

[0012] ONU1 is installed on the subscriber premises side of the communication system 100, and transmits optical signals from OLT2 to the subscriber's local network or computer, and transmits optical signals from the subscriber's local network or computer to OLT2. OLT2 combines optical signals from lines or devices on the upper network side and transmits them to ONU1, and transmits optical signals received from ONU1 to lines or devices on the upper network side. Optical splitter 3 splits optical signals from OLT2 to ONU1, and aggregates optical signals from ONU1 to OLT2.

[0013] 1, the ONU 1 includes a communication unit 11, a control device 12, a voltage monitoring unit 13, and a power adapter 14. The control device 12 includes a control unit 121, a non-volatile storage unit 122, a volatile storage unit 123, and an input / output unit 124.

[0014] The communication unit 11 is, for example, an optical transceiver for an EPON system. The communication unit 11 receives an optical signal transmitted from the OLT 2, converts it into an electrical signal, and outputs it to the control device 12. The communication unit 11 also converts an electrical signal output from the control device 12 into an optical signal, and transmits it to the OLT 2.

[0015] The control unit 121 is a processor such as a CPU, and realizes EPON communication with the OLT 2. Moreover, the control unit 121 of this embodiment performs an abnormality detection process, which will be described later, by executing an abnormality detection program stored in the non-volatile storage unit 122. The control unit 121 may be configured with an ASIC or FPGA, or may be configured with a combination of a CPU and an ASIC or FPGA.

[0016] The non-volatile storage unit 122 is a non-volatile memory that retains memory even when there is no power supply, such as a ROM, a flash memory, or a hard disk drive. The non-volatile storage unit 122 stores an abnormality detection program executed by the control unit 121, parameters required for executing the abnormality detection program, notification information indicating that a voltage drop notification has been sent to the OLT 2, and the like.

[0017] Volatile storage unit 123 is a volatile memory such as RAM, DRAM, or SRAM that cannot retain data when power is not supplied. As an example, volatile storage unit 123 is a register of a CPU constituting control unit 121. When power to ONU1 is turned off, data stored in volatile storage unit 123 is cleared and returned to the initial value. Furthermore, when control unit 121 (CPU) is reset, data stored in volatile storage unit 123 is not cleared but is retained.

[0018] The input / output unit 124 is an input / output port that transmits and receives signals between the control unit 121 and the voltage monitoring unit 13. As an example, the input / output unit 124 is a general purpose input / output (GPIO). The control unit 121 and the voltage monitoring unit 13 are connected to the input / output unit 124 via an internal bus.

[0019] When the power supply of ONU1 is ON, the voltage monitoring unit 13 monitors the power supply voltage (e.g., 12V) input from the power adapter 14. When the power supply voltage is equal to or higher than a preset threshold, the voltage monitoring unit 13 outputs a High signal to the input / output unit 124 of the control device 12. When the power supply voltage is below the threshold, the voltage monitoring unit 13 outputs a Low signal to the input / output unit 124 of the control device 12. The power adapter 14 converts commercial power to a power supply voltage of 12V and supplies it to each unit of the ONU1.

[0020] 2 is a diagram for explaining the flow of operations when the power supply of the ONU1 is turned off in the first embodiment. The power supply of the ONU1 is turned off due to a power outage or intentionally by a user. When the power supply of the ONU1 is turned off, first, the power supply voltage monitored by the voltage monitoring unit 13 becomes less than a preset threshold value (S1), and a Low signal is sent from the voltage monitoring unit 13 to the control unit 121 via the input / output unit 124 (S2). When the control unit 121 receives the Low signal from the voltage monitoring unit 13, it determines that a power-off interrupt has occurred, and sends a DyingGasp notification to the OLT2 (S3).

[0021] By receiving the DyingGasp notification from the ONU1, the OLT2 detects that the power supply of the ONU1 has been turned off. When the communication between the OLT2 and the ONU1 is cut off, the cause may be that the power supply of the ONU1 has been turned off, that the optical fiber line between the OLT2 and the ONU1 has been broken, that the user has intentionally pulled out the optical fiber, or some other malfunction. As in this embodiment, by transmitting the DyingGasp notification to the OLT2 before the power supply of the ONU1 is turned off, the OLT2 can know that the cause of the cut off of the communication with the ONU1 is that the power supply of the ONU1 has been turned off.

[0022] Furthermore, when the control unit 121 transmits the DyingGasp notification to the OLT 2, it transmits notification information indicating that the DyingGasp notification has been transmitted to the non-volatile storage unit 122 (S4). The non-volatile storage unit 122 stores the notification information indicating that the DyingGasp notification has been transmitted in an arbitrary area (S5). The notification information may include, in addition to the fact that the DyingGasp notification has been transmitted, the date and time when the notification was transmitted.

[0023] The non-volatile storage unit 122 stores notification information only when a notification is transmitted to the OLT 2. For example, when the voltage monitoring unit 13 is faulty, the voltage monitoring unit 13 cannot transmit a Low signal to the control unit 121 even if the power supply voltage drops, and therefore the control unit 121 cannot transmit a DyingGasp notification to the OLT 2. In this case, the non-volatile storage unit 122 does not store notification information either.

[0024] FIG. 3 is a flowchart showing the flow of the abnormality detection process in the ONU1 according to the first embodiment. The flowchart in FIG. 3 is started by the control unit 121 of the ONU1 when the ONU1 is started. The ONU1 is started when the power supply of the ONU1 is turned from OFF to ON, or when the CPU constituting the control unit 121 of the ONU1 is reset. First, the control unit 121 judges whether or not the register value of the volatile storage unit 123 is an initial value (S11). When the power supply of the ONU1 is turned ON after being turned OFF, the volatile storage unit 123 clears the stored data to the initial value, and when the CPU of the control unit 121 is reset, the state before the reset is maintained. Therefore, it is possible to judge whether or not the power supply of the ONU1 has been turned OFF, depending on whether or not the register value of the volatile storage unit 123 is the initial value.

[0025] If the register value of the volatile storage unit 123 is not the initial value (S11: NO), the control unit 121 determines that the power supply of the ONU1 has not been turned off, and continues the startup (S14). On the other hand, if the register value of the volatile storage unit 123 is the initial value (S11: YES), the control unit 121 determines that the power supply of the ONU1 has been turned off, and determines whether or not notification information is stored in the non-volatile storage unit 122 (S12).

[0026] If the notification information is stored in the non-volatile storage unit 122 (S12: YES), the control unit 121 determines that the DyingGasp notification was sent to the OLT 2 when the power was turned off and that the voltage monitoring unit 13 is normal, and deletes the notification information from the non-volatile storage unit 122 (S13). After that, the control unit 121 continues the startup (S14).

[0027] On the other hand, if the notification information is not stored in the non-volatile storage unit 122 (S12: NO), the control unit 121 determines that the DyingGasp notification was not sent to the OLT 2 when the power was turned off, that is, that the voltage monitoring unit 13 did not output a Low signal, and determines that the voltage monitoring unit 13 has failed (S15). In this case, the control unit 121 sets the failure of the voltage monitoring unit 13 in the alarm log.

[0028] Then, the control unit 121 executes failure processing (S16). In the failure processing, processing such as notifying the OLT 2 that the voltage monitoring unit 13 has failed or turning off the power supply of the ONU 1 is performed, and the notification information in the non-volatile storage unit 122 is deleted.

[0029] 4 is a diagram explaining the flow of operations when the power supply of the ONU5 is turned off in a communication system 500 according to the conventional technology. In the conventional communication system 500, when the voltage monitoring unit 53 detects a drop in the power supply voltage from the power adapter 54 due to the power supply of the ONU5 being turned off, the voltage monitoring unit 53 transmits a Low signal to the control unit 52. When the control unit 52 receives the Low signal from the voltage monitoring unit 53, the control unit 52 transmits a DyingGasp notification to the OLT2. By receiving the DyingGasp notification from the ONU5, the OLT2 can know that the power supply of the ONU5 has been turned off.

[0030] However, in the case of the conventional technology, if the voltage monitoring unit 53 of the ONU 5 fails, even if the power supply of the ONU 5 is turned off, the voltage monitoring unit 53 does not transmit a Low signal to the control unit 52, and the control unit 52 cannot transmit a DyingGasp notification to the OLT 2. Therefore, the OLT 2 only knows that the communication between the OLT 2 and the ONU 1 has been cut off, making it difficult to identify the abnormality.

[0031] In contrast, in this embodiment, when the control unit 121 of the ONU1 issues a DyingGasp notification by an interrupt of a Low signal from the voltage monitoring unit 13 when the power supply of the ONU1 is turned off, the notification information is stored in the non-volatile storage unit 122. As a result, at the next startup, it becomes possible to detect an abnormality in the voltage monitoring unit 13 by checking the presence or absence of the notification information in the non-volatile storage unit 122. Also, by detecting an abnormality in the voltage monitoring unit 13 in the ONU1, the cause of the abnormality in the communication system 100 can be identified in the OLT2 at an early stage.

[0032] Embodiment 2 5 is a flowchart showing the flow of an abnormality detection process in the ONU 1 according to the embodiment 2. In the embodiment 2, a part of the abnormality detection process performed in the ONU 1 is different from that in the embodiment 1. Other configurations of the communication system 100 and other operations of the ONU 1 are the same as those in the embodiment 1.

[0033] The flowchart of FIG. 5 is started by the control unit 121 of the ONU1 when the ONU1 is started, as in the first embodiment. First, the control unit 121 judges whether or not the register value of the volatile storage unit 123 is an initial value (S21). Then, if the register value of the volatile storage unit 123 is an initial value (S21: YES), the control unit 121 judges that the power supply of the ONU1 has been turned off, and judges whether or not notification information is stored in the non-volatile storage unit 122 (S22). The processing of steps S22 to S26 in the second embodiment is the same as the processing of steps S12 to S16 in the first embodiment. This makes it possible to detect an abnormality in the case where the voltage monitoring unit 53 does not transmit a Low signal even though the power supply has been turned off in the ONU1.

[0034] In this embodiment, even if the register value of the volatile storage unit 123 is not the initial value (S21: NO), the control unit 121 judges whether or not the notification information is stored in the nonvolatile storage unit 122 (S27). If the register value of the volatile storage unit 123 is not the initial value, it can be judged that the power supply of the ONU1 is not turned off. However, if the voltage monitoring unit 13 is faulty, a Low signal may be transmitted even though the power supply is not turned off. In this case, even though the power supply is not turned off, a DyingGasp notification is transmitted to the OLT2, and the notification information is stored in the nonvolatile storage unit 122. Therefore, it is possible to judge the failure of the voltage monitoring unit 13 from the presence or absence of the notification information in the nonvolatile storage unit 122 when the power supply is not turned off.

[0035] If no notification information is stored in the non-volatile storage unit 122 (S27: NO), the control unit 121 determines that the voltage monitoring unit 13 is normal and continues the startup (S24). On the other hand, if notification information is stored in the non-volatile storage unit 122 (S27: YES), the control unit 121 determines that the voltage monitoring unit 13 is faulty because a DyingGasp notification has been sent to the OLT 2 even though the power is not turned off (S25), and executes fault processing (S26).

[0036] In this embodiment, it becomes possible to detect various abnormalities in the voltage monitoring unit 13 by combining the state of the data stored in the volatile storage unit 123 and the presence or absence of notification information in the non-volatile storage unit 122. Furthermore, by detecting an abnormality in the voltage monitoring unit 13 in the ONU 1, the cause of the abnormality in the communication system 100 can be identified in the OLT 2 at an early stage.

[0037] The above is an explanation of the embodiment of the present invention, but the present invention is not limited to the configuration of the above embodiment, and various modifications or combinations are possible within the scope of the technical idea. For example, in the above embodiment, an abnormality detection method in the ONU1 of the EPON system is explained, but the present invention is applicable to communication devices other than the ONU1. For example, the present invention can be applied to communication devices such as a router or a home gateway, in which an interrupt is input to the control unit when the power is turned off, by using a general-purpose input / output unit such as a GPIO between the voltage monitoring unit and the control unit (CPU). In addition, the device to which the communication device transmits a notification when the communication device is turned off is not limited to the OLT2, and may be any external device to which the communication device is connected so as to be able to communicate by wire or wirelessly.

[0038] In the above embodiment, the voltage monitoring unit 13 outputs a High signal when the power supply voltage is equal to or higher than a preset threshold, and outputs a Low signal when the power supply voltage is less than the threshold, but this is not limited thereto. The voltage monitoring unit 13 may output a voltage drop signal indicating that the power supply voltage has dropped when the power supply voltage is less than a preset threshold. In addition, the notification that the control unit 121 transmits to the OLT 2 when receiving a voltage drop signal from the voltage monitoring unit 13 is not limited to a DyingGasp notification, but may be a power OFF notification indicating that the power supply of the ONU 1 has been cut off. In the above embodiment, the determination is made as to whether the power supply of the ONU 1 has been turned off based on the register value stored in the volatile storage unit 123, but this is not limited thereto. Power OFF information indicating that the power supply of the ONU 1 has been turned off may be separately stored in the non-volatile storage unit 122, the volatile storage unit 123, or another storage unit of the ONU 1. [Explanation of symbols]

[0039] 1 ONU, 2 OLT, 3 optical splitter, 5 ONU, 11 communication unit, 12 control device, 13 voltage monitoring unit, 14 power adapter, 51 communication unit, 52 control unit, 53 voltage monitoring unit, 54 power adapter, 100 communication system, 121 control unit, 122 non-volatile memory unit, 123 volatile memory unit, 124 input / output unit, 500 communication system.

Claims

1. A communication unit that communicates with an external device; a voltage monitoring unit that monitors a power supply voltage and outputs a voltage drop signal when the power supply voltage falls below a threshold; a control unit that transmits a power OFF notification to the external device when the voltage drop signal is received from the voltage monitoring unit; a storage unit that stores notification information indicating that the power-off notification has been transmitted and power-off information indicating that the power has been turned off; The control unit detects a failure of the voltage monitoring unit based on the notification information and the power OFF information at the time of startup of the communication device.

2. The storage unit is A non-volatile storage unit that stores the notification information; A volatile storage unit that stores the power OFF information, The communication device according to claim 1 , wherein the power-off information is a register value.

3. The communication device according to claim 2 , wherein the control unit determines that the voltage monitoring unit is at fault if the register value is an initial value at the time of startup and the notification information is not stored in the non-volatile storage unit.

4. The communication device according to claim 2 , wherein the control unit determines that the voltage monitoring unit is malfunctioning if the register value is not an initial value at the time of startup and the notification information is stored in the non-volatile storage unit.

5. A method for detecting an abnormality in a communication device, comprising: a step of monitoring a power supply voltage by a voltage monitoring unit, and outputting a voltage drop signal when the power supply voltage falls below a threshold; a step of transmitting a power OFF notification to an external device by a control unit when the voltage drop signal is received from the voltage monitoring unit; When the power-off notification is transmitted to the external device, storing notification information indicating that the power-off notification has been transmitted in a storage unit; detecting, by the control unit at the time of startup, a failure in the voltage monitoring unit based on the notification information and power-off information indicating that the power has been turned off.

6. An anomaly detection program that causes a processor of the communication device to execute the anomaly detection method according to claim 5.

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