JP2014107676A - Failure determination device, failure determination method, and failure determination program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to easily investigate a failure cause of a device for a short time.SOLUTION: The failure determination device comprises: a correspondence table which indicates correspondence between a failure state of each section in the device and a failure cause estimated in the device; a memory; and a control section which acquires monitoring information indicating whether each section is in the failure state or not, selects from the correspondence table the failure cause estimated on the basis of the monitoring information and the correspondence table, and stores the acquired monitoring information and the selected failure cause in the memory.

Description

  The present invention relates to a failure determination device, a failure determination method, and a failure determination program, and more particularly to a failure determination device having a configuration for storing information for monitoring operation.

  An SFP (Small Form Factor Pluggable) optical transceiver is a standardized interface module that mutually converts an optical signal and an electrical signal, and is used by being mounted on a communication device. Since the SFP optical transceiver is mounted on various devices such as a communication device and a mobile phone base station device, the number of shipments has been increasing in recent years.

  Some SFP optical transceivers have a digital diagnostic monitoring (DDM) function. The DDM function is a function for monitoring the operation state of the SFP optical transceiver in real time. With the DDM function, when an abnormality occurs in the SFP optical transceiver, the operation status can be confirmed, and the cause of the abnormality can be easily analyzed. For this reason, some communication apparatuses have a function of monitoring the operation status of the SFP optical transceiver using the DDM function.

  However, whether or not the communication device on which the SFP optical transceiver is mounted performs monitoring using the DDM function depends on the function of the communication device. For this reason, if the communication device does not support the DDM function, the maintenance person of the communication device or the SFP optical transceiver cannot grasp in detail the failure occurrence state of the SFP optical transceiver. As a result, there has been a problem that it may take time to investigate the cause of a failure when a failure occurs.

  Moreover, since the status confirmation of the SFP optical transceiver by the DDM function is real time, only the information at that time can be confirmed. For this reason, even if the DDM function is used, it is not possible to grasp the time-series operation status of the SFP optical transceiver, and the DDM function has a problem that the status that can be analyzed is limited.

  In relation to such a problem, Patent Document 1 acquires the operation status data of each part, and in the normal state, the operation status data is stored in the history information. When an abnormality occurs in the optical transceiver, the history information is updated. An optical transceiver with a configuration that is stopped is disclosed. In the optical transceiver described in Patent Document 1, the cause of the failure can be analyzed based on the history information of the operation state stored before the failure occurs.

JP 2005-117416 A

  The optical transceiver described in Patent Literature 1 can analyze the cause of failure based on the stored history information. However, in the technique described in Patent Document 1, only the operation status of each unit is stored. For this reason, in order to know the cause of the failure of the optical transceiver, a skilled worker needs to investigate the cause of the failure based on the history information of a plurality of locations inside the optical transceiver.

  On the other hand, as the number of SFP optical transceivers shipped increases, it is required to analyze the cause of failure in a short time and easily. However, since the optical transceiver described in Patent Document 1 requires analysis by a skilled worker to investigate the cause of failure, the cause of failure cannot be easily investigated in a short time.

(Object of invention)
An object of this invention is to provide the technique for investigating the cause of a failure of an apparatus easily in a short time.

  The failure determination apparatus of the present invention shows a correspondence table showing a correspondence between failure states of each part of the device and the estimated cause of failure of the device, a memory, and whether the state of each part is in the failure state. Monitoring information is acquired at a predetermined frequency, the estimated cause of failure is selected from the correspondence table based on the monitoring information and the correspondence table, and the acquired monitoring information and the selected failure cause are selected. And a control unit for storing in the memory.

  The failure determination method of the present invention acquires monitoring information indicating whether the state of each part of the device is in a failure state at a predetermined frequency, and acquires the monitoring information, the failure state of each part, and the estimated failure of the device. The estimated cause of failure is selected based on a correspondence table indicating correspondence with causes, and the monitoring information and the selected cause of failure are stored in a memory.

  The failure determination program of the present invention includes a procedure for acquiring monitoring information indicating whether or not the state of each part of the device is in a failure state at a predetermined frequency, the monitoring information, the failure state of each part, and the estimated device A correspondence table showing correspondence of failure causes of the device, a procedure for selecting the failure cause of the device estimated based on, and a procedure for storing the monitoring information and the selected failure cause in a memory. It is made to perform.

  The present invention has an effect that the cause of the failure of the optical module can be investigated easily in a short time.

It is a block diagram which shows the structure of the optical transceiver of 1st Embodiment. It is a flowchart which shows operation | movement of a control part. It is a table | surface which shows the example of the monitoring information preserve | saved at memory. It is an example of the table | surface used for estimation of a failure cause. It is a figure which shows the structure of the failure determination apparatus of 2nd Embodiment.

(First embodiment)
FIG. 1 is a block diagram showing the configuration of the optical transceiver of the first embodiment of the present invention. The optical transceiver 10 is an SFP optical transceiver having a DDM function, and includes an optical module 20 and a management unit 70. The optical module 20 is an interface between an optical signal and an electrical signal that includes an LD (laser diode) 21 as a light emitting element and a PD (photo diode) 22 as a light receiving element. The LD 21 transmits an optical signal to another opposing optical transceiver (not shown). The PD 22 receives an optical signal from another opposing optical transceiver, converts it into an electrical signal, and outputs it.

  The management unit 70 includes a driver 30, an amplifier 40, a control unit 50, and a memory 60. The driver 30 generates a drive current that drives the LD 21 based on the electrical signal input from the communication device 91. The amplifier 40 amplifies the electrical signal converted from the optical signal received by the PD 22 and outputs it to the communication device 91.

  The control unit 50 controls the driver 30 so that the LD 21 operates with a predetermined optical output power, and controls the amplifier 40 so that a signal output from the PD 22 has a predetermined amplitude.

  The control unit 50 further includes a DDM function, and generates monitoring information indicating the operation status of each unit of the optical transceiver 10.

  The memory 60 stores monitoring information generated by the control unit 50. The memory 60 may be a non-volatile memory. In addition, the memory 60 stores an initial value at the start of use of an item stored as monitoring information and a threshold value determined to be a failure. Operation instructions and monitoring information may be read from the external control device 92 to the control unit 50 and the memory 60. Further, the communication device 91 on which the SFP optical transceiver is mounted may also serve as the control device 92. Alternatively, the control device 92 may be a device for investigating the SFP optical transceiver.

  FIG. 1 shows a basic configuration of the optical transceiver 10, and specific components can be arbitrarily selected. For example, a one-chip integrated circuit having the functions of the driver 30, the amplifier 40, the control unit 50, and the memory 60 may be used as the management unit 70. Alternatively, as the driver 30 and the amplifier 40, an integrated circuit having functions of an LD driver and a limiting amplifier may be used. The memory 60 may be a physical memory independent of the control unit 50, or a storage area provided in any of the driver 30, the amplifier 40, and the control unit 50 may be used as the memory 60.

  The control unit 50 further includes a CPU (central processing unit) and a program storage unit, and the function of the control unit 50 may be realized by the CPU executing the program.

Information of the SFP optical transceiver monitored by the DDM function is defined by SFF-8472, which is a DDM interface specification of the SFP optical transceiver, formulated by, for example, the SFF (small form factor) Committee. In SFF-8472, there are five items monitored as numerical values: temperature, power supply voltage, supply bias current to LD, optical output power, and received optical power. Other items to be monitored include Alarm and Warning such as LOS (Loss of Signal) and TxFault (transmission circuit failure). Normally, these pieces of information monitored by the DDM function (hereinafter referred to as “monitoring information”) are read out from an external device via an I ² C (Inter-Integrated Circuit) interface or the like. In this case, the external device becomes the master, and the monitoring information of the optical transceiver as a slave is sequentially read out to the master side.

  The controller 50 autonomously collects monitoring information at a predetermined frequency and stores it in the memory 60 even when there is no instruction from the outside of the optical transceiver 10. The frequency at which the control unit 50 collects the monitoring information may be either a constant cycle or an indefinite cycle. Further, the control unit 50 may start collecting monitoring information of the optical transceiver 10 in response to a read request from the external control device 92 or a collection request for monitoring information.

  FIG. 2 is a flowchart showing the operation of the control unit 50. The flow described in FIG. 2 will be described below.

  When the control unit 50 acquires monitoring information by the DDM function at a predetermined frequency, the control unit 50 stores the acquired monitoring information in the memory 60 (step S101 in FIG. 2).

  The control unit 50 determines whether or not a failure has occurred based on the acquired monitoring information. That is, the control unit 50 checks whether there is an item in the acquired monitoring information that exceeds a threshold value that is determined to be a failure, and whether the Alarm / Warning flag is set (S102). ).

  The control unit 50 determines that a failure has occurred when there is monitoring information whose value exceeds a threshold value. In addition, the Alarm / Warning flag defined by SFF-8472 can be used to determine the occurrence of a failure in the optical transceiver. The Alarm / Warning flag is set when the optical transceiver no longer satisfies the specifications of the optical transceiver specified by the manufacturer. Therefore, even when the Alarm / Warning flag is set, the control unit 50 determines that a failure has occurred in the optical transceiver 10.

  When it is determined that a failure has occurred, or when Alarm or Warning is included in the monitoring information (S102: Yes, hereinafter referred to as “when a failure has occurred”), processing upon occurrence of the failure (S201). To S208). The procedure from S201 to S208 will be described later.

  When it is not determined that a failure has occurred in the monitoring information (S102: No), the control unit 50 checks the free capacity of the memory 60 (S103).

  When the control unit 50 determines that the memory 60 has sufficient free space for storing monitoring information to be acquired in the future (S103: Yes), the process returns to the monitoring information acquisition step (S101), and the predetermined amount is set. The following processing is repeated at a frequency of Note that the control unit 50 may determine that there is sufficient free space, for example, when the memory 60 can store the monitoring information acquired next time in the memory 60.

  When it is determined that the memory 60 does not have enough free space for storing monitoring information acquired in the future (S103: No), the control unit 50 deletes the past monitoring information stored in the memory 60. (S104). By erasing past monitoring information, an area for storing new monitoring information is secured. The past monitoring information to be deleted is, for example, the oldest monitoring information. When the past monitoring information is deleted, the monitoring information acquisition step (S101) is repeated.

  Next, processing (S201 to S208) when a failure occurs will be described.

  The control unit 50 includes first and second procedures described below as processing when a failure occurs (S102: Yes). Note that which procedure is executed in S201 is set in advance by the user of the optical transceiver 10.

  When the first procedure is selected (S201: Procedure 1), when a failure occurs, the acquisition and storage of future monitoring information is stopped (S202).

  On the other hand, when the second procedure is selected (S201: procedure 2), the monitoring information is acquired and stored even after a failure occurs. However, in the second procedure, the number of times monitoring information is acquired after the occurrence of a failure is limited.

  Specifically, in the second procedure, the control unit 50 sets the upper limit of the number of acquisitions to N, sets the number of acquisitions n of the monitoring information after the failure to 1 (S203), and n is the upper limit value N of the number of acquisitions. It is confirmed whether or not (S204). Here, n and N are natural numbers. When the number n of monitoring information acquisition after the failure has reached the upper limit value N (step S204: Yes), the subsequent monitoring information acquisition is stopped (S202). When the number n of monitoring information acquisition after the failure has not reached the upper limit value N (step S204: No), the control unit 50 increases n by 1 (S205), and frees up the free space of the memory 60. Confirm (S206).

  When the control unit 50 determines that the memory 60 has sufficient free space for storing monitoring information acquired in the future (S206: Yes), the predetermined frequency is set as in step S101 of FIG. In step S207, the monitoring information is acquired, and the acquired monitoring information is stored in the memory 60.

  When the control unit 50 determines that there is not enough free space in the memory 60 for storing monitoring information acquired in the future (S206: No), the past monitoring information stored in the memory 60 is deleted. (S208), acquisition of monitoring information is continued (S207).

  Thus, in the second procedure, an upper limit is set on the number of times monitoring information is acquired after the occurrence of a failure. Accordingly, the second procedure makes it possible to prevent the data at the time of the occurrence of the failure stored in the past from being judged as old data and being erased by repeating the acquisition of the monitoring information. As a result, an operator who is investigating the cause of the failure can easily analyze the content of the failure by analyzing the monitoring information stored in the memory 60 even when a long time has elapsed since the occurrence of the failure. Is possible.

  In the second procedure, monitoring information after the occurrence of the failure is stored in addition to the occurrence of the failure of the optical transceiver. Therefore, when the capacity of the memory 60 is sufficient, the second procedure may be selected in consideration of the convenience of investigating the cause of failure at a later date.

  Further, when it is determined that a failure has occurred (S102: Yes), the free capacity of the memory 60 is confirmed, and if the memory 60 has enough capacity, the procedure of the second procedure is executed. When the capacity of 60 is small, the first procedure may be executed.

  FIG. 3 is a table showing an example of monitoring information stored in the memory 60. As monitoring information, the measured values of ambient temperature, power supply voltage, bias current, optical output power, and received optical power, the states of the LOS flag and the TxFault flag, and the states of other Alarm and Warning flags are recorded. In the flag state in FIG. 3, “reset” indicates that the flag is not set, that is, alarm or warning indicating a failure has not occurred.

  In the monitoring information, an acquisition date, an acquisition time, an initial value, and a threshold value for determining a failure as well as the measurement value are recorded. FIG. 3 is a table showing monitoring information at 12:00 on November 1, 2012 as an example. Each time monitoring information is acquired, the table of FIG. 3 is generated and stored in the memory 60. Note that the initial value and the threshold value are usually constant values that do not change each time monitoring information is acquired, and therefore may be stored in the memory 60 as information different from the monitoring information. In addition, when the acquisition time can be calculated from the monitoring information acquisition cycle or the like, the monitoring information need not be stored together with the acquisition time.

  A relationship between a combination of whether each monitoring information indicates a failure state and a failure content estimated from the combination is stored in the memory 60 in advance.

  FIG. 4 is an example of a table used for the above-described failure cause estimation. FIG. 4 shows the cause of failure estimated based on the state of other monitoring items when the monitoring current of the optical output power of the LD falls below a threshold value and becomes a failure state.

  When the control unit 50 determines from the acquired monitoring information that a failure has occurred, the control unit 50 estimates the content of the failure based on FIG. 4 from the abnormal monitoring information item. For example, when the monitor current of the optical output power of the LD 21 falls below the threshold value and becomes a failure state, the control unit 50 estimates the content of the failure according to the following procedure using FIG.

  The optical output power of the LD 21 is obtained by conversion from the output current (monitor current) of the monitor PD that monitors the optical output power of the LD 21. Conversion from the monitor current to the output power of the LD 21 is performed based on data at the time of manufacturing the LD 21. Possible causes for the monitor current to fall below the threshold value include, for example, degradation of the slope efficiency (conversion efficiency from current to optical output) of the LD 21, failure of the driver 30, and reduction of the power supply voltage. Here, when the monitor current has decreased below the threshold value and the bias current is normal, the control unit 50 estimates that the cause of the failure is a deterioration in the slope efficiency of the LD 21.

  If the bias current is below the threshold in addition to the decrease in the monitor current, there is a possibility that the bias current of the LD 21 has decreased due to a failure of the driver 30 or a decrease in the power supply voltage. Therefore, when the monitor current and the bias current are below the threshold values and the power supply voltage is normal, the control unit 50 estimates that the cause of the failure is a failure of the driver 30. When the power supply voltage is below the threshold, the control unit 50 estimates that the power supply has failed. In this case, it is considered that the output bias current of the driver 30 is lowered due to the failure of the power source, and as a result, the monitor current of the optical output power of the LD is lowered. The failure cause estimation procedure described here is merely an example, and does not exclude other estimation procedures.

  The control unit 50 records the estimated cause of failure in the memory 60. As a result, the operator who analyzes the failure cause of the optical transceiver can read the estimated failure cause directly from the memory 60 and can immediately know the estimated failure cause without analyzing the individual monitoring information. .

  As described above, in the optical transceiver of the first embodiment, the relationship between the combination of whether each monitoring information indicates a failure state and the failure content estimated from the combination is stored in the memory 60 in advance. Saved. Then, the cause of failure estimated based on the monitoring information is recorded in the memory 60.

  For this reason, in the optical transceiver of the first embodiment, the operator who analyzes the optical transceiver reads out the estimated cause of the failure, so that the work time required for estimating the cause of the operator's failure can be reduced. The cause of the failure can be easily estimated without depending on the skill level of.

  That is, the optical transceiver of the first embodiment has an effect that the cause of the failure of the optical module can be investigated in a short time and easily.

  In addition, the operator can quickly know if a similar failure has occurred in the same optical transceiver in the past by reading the cause of failure estimated by the optical transceiver itself, It is also possible to shorten the time for studying the policy for countermeasures against failures.

  Furthermore, the optical transceiver according to the first embodiment includes the memory 60, and can acquire and store monitoring information before and after the occurrence of the failure. For this reason, even when the optical transceiver fails, time-series information before and after the occurrence of the failure can be confirmed. As a result, it becomes easy to grasp the failure occurrence status and analyze the cause of the failure of the optical transceiver thereafter. Further, by reading the stored monitoring information without reproducing the failure occurrence state in detail, the operator can obtain information on the failure occurrence status and the subsequent transition. As a result, the monitoring information is acquired in detail in time, it becomes possible to know in detail the status transition of the SFP optical transceiver during operation, and the failure cause analysis is further facilitated.

Note that the monitoring information may be acquired and stored only after the failure has occurred, only the item in which the failure has occurred, or only the failure occurrence item and its related item. Thereby, the consumption of the memory 60 can be reduced, and data can be acquired for a longer time after the occurrence of a failure.
(First modification of the first embodiment)
In the optical transceiver 10 of the first embodiment, monitoring information by DDM is stored in the memory 60 for investigating a failure. However, as a first modification thereof, the stored monitoring information may be used for maintaining the optical output power.

  When the optical output power of the LD 21 included in the optical transceiver decreases, the monitoring information includes information indicating an abnormality such as a decrease in the current of the monitor PD that monitors the optical output power of the LD 21 or a decrease in the bias current of the LD 21. There is a case.

  Therefore, when the monitoring information regarding the LD 21 indicates such an abnormality, the control unit 50 controls the driver 30 to increase the bias current of the LD 21 so that the current of the monitor PD of the LD 21 approaches the initial value. You may let them. The initial value of the optical output power monitor used here is stored in the memory 60, for example.

(Second modification of the first embodiment)
In the first embodiment, the optical transceiver 10 stores the acquired monitoring information in the memory 60 included in the optical transceiver 10. However, when a plurality of optical transceivers are used in combination, the acquired monitoring information may be stored in other optical transceivers.

  If a failure occurs in the memory 60 of the optical transceiver from which the monitoring information is obtained, the monitored data may not be stored normally. Therefore, the control unit 50 and the memory 60 included in each of the plurality of optical transceivers may be connected so as to be controllable via the communication device 91. Since the control unit 50 and the memory 60 are connected to each other among the plurality of optical transceivers, a copy of the same monitoring information can be stored in the memory 60 of another optical transceiver. As a result, when the memory 60 of the optical transceiver from which the monitoring information is acquired fails, the monitoring information is stored in another optical transceiver, so that the monitoring information of the optical transceiver to be investigated can be obtained from the other optical transceiver. You can get it.

  In addition, when the storage capacity of the memory 60 of an optical transceiver is tight, storing the monitoring information in another optical transceiver substantially increases the memory capacity and the monitoring information is lost without being stored. Can be avoided.

(Second Embodiment)
FIG. 5 is a diagram illustrating a configuration of a failure determination apparatus 500 according to the second embodiment of the present invention. The failure determination apparatus 500 includes a correspondence table 501, a control unit 502, and a memory 503. The correspondence table is a table showing a correspondence between a failure state of each part of a device that is a target of failure determination and an estimated cause of failure of the device. The control unit acquires monitoring information indicating whether or not the state of each unit that is the target of failure determination is in a failure state at a predetermined frequency from the outside of the failure determination device 500, and based on the acquired monitoring information and the correspondence table 501. Thus, the estimated failure cause is selected from the correspondence table 501. Further, the control unit 502 stores the acquired monitoring information and the selected cause of failure in the memory 503. The monitoring information stored in the memory 503 is read from the outside of the failure determination apparatus 500.

  The failure determination apparatus 500 having such a configuration estimates a failure cause of the device based on the monitoring information and the correspondence table 501, and stores the estimated monitoring information and the estimated failure cause in the memory 503.

  By reading out the estimated failure cause from the memory 503 by a worker who investigates the failure of the device, the work time required to estimate the cause of the failure of the worker can be reduced, and it does not depend on the skill level of the worker and is easy The cause of equipment failure can be estimated.

  In other words, the failure determination apparatus 500 has an effect that the cause of the failure of the device can be investigated easily in a short time.

  As described above, the present invention has been described with reference to the embodiment, but the present invention is not limited to the above-described embodiment and its modifications. Various changes that can be understood by those skilled in the art can be made to the configuration and details of the present invention within the scope of the present invention.

10 Optical transceiver 20 Optical module 21 LD (Laser diode)
22 PD (photodiode)
30 Driver 40 Amplifier 50 Control Unit 60 Memory 70 Management Unit 91 Communication Device 92 Control Device 500 Failure Determination Device 501 Correspondence Table 502 Control Unit 503 Memory

Claims (9)

Correspondence table showing the correspondence between the failure state of each part of the device and the cause of failure estimated in the device;
Memory,
Monitoring information indicating whether the state of each part is in the failure state is acquired at a predetermined frequency, and the estimated cause of failure is selected from the correspondence table based on the monitoring information and the correspondence table, And a controller that stores the acquired monitoring information and the selected cause of failure in the memory.   2. The failure determination device according to claim 1, wherein when the acquired monitoring information indicates a failure state, the control unit limits the number of subsequent acquisitions of the monitoring information.   The failure determination device according to claim 2, wherein the limited number of acquisitions is determined based on a capacity of the memory capable of storing the monitoring information.   The failure determination device according to claim 1, wherein the control unit duplicates the same monitoring information and causes another failure determination device to store the duplicate.   The failure determination device according to claim 1, wherein the control unit causes a part of the monitoring information to be stored in another failure determination device. Furthermore, the optical transmission part which converts the input electrical signal into an optical signal, and outputs it, The optical reception part which converts the received optical signal into an electrical signal, and outputs it, It is described in any one of Claims 1 thru | or 5. A failure determination device,
The optical transceiver is configured to collect the monitoring information indicating whether each unit of the optical transmission unit and the optical reception unit is in the fault state.   The optical transceiver according to claim 6, wherein the optical transceiver conforms to an SFP (Small Form Factor Pluggable) specification and the monitoring information is provided by a DDM (Digital Diagnostic Monitoring) function. Monitoring information indicating whether the state of each part of the device is in a failure state is acquired at a predetermined frequency,
Based on the monitoring information and a correspondence table showing a correspondence between a failure state of each part and a failure cause estimated in the device, the estimated failure cause is selected,
Storing the monitoring information and the selected cause of failure in a memory;
A failure determination method characterized by the above. A procedure for acquiring monitoring information indicating whether the state of each part of the device is in a failure state at a predetermined frequency;
A procedure for selecting the estimated cause of failure based on the monitoring information and a correspondence table indicating correspondence between failure states of the respective units and estimated cause of failure in the device;
Storing the monitoring information and the selected cause of failure in a memory;
A failure determination program that causes a computer to execute

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