JP4599822B2 - Optical transceiver - Google Patents

Description

  The present invention relates to an optical transceiver.

Along with recent technological innovations, intelligent optical transceivers with built-in CPUs have been developed. In such an optical transceiver, data related to the operating status and environmental status of each unit inside the optical transceiver (for example, optical input level) is acquired as needed, and each unit inside the optical transceiver is acquired based on each acquired data. A function to control is provided. As such a function, for example, when the acquired data is data related to the optical input level, the bias value to be given to the APD (Avalanche Photo Diode) of the receiving unit is controlled based on the data related to the optical input level. There is a function. A technique related to such an optical transceiver is described in, for example, Patent Document 1 below.
US Patent Application Publication No. 2002/0149821

  However, since the above-described optical transceiver has a plurality of functions for performing control based on each data, it is difficult to identify the cause of the failure when a failure occurs in the optical transceiver.

  In order to solve the above-described problems, an object of the present invention is to provide an optical transceiver and an optical transceiver management system capable of accurately grasping the cause of a failure that has occurred in the optical transceiver.

  An optical transceiver according to the present invention includes a light emitting element that converts an electrical signal into an optical signal, a light receiving element that converts an optical signal into an electrical signal, a data acquisition unit that acquires predetermined data, and a predetermined acquired by the data acquisition unit. And determining means for determining whether or not the predetermined data is normal based on the predetermined data and the predetermined threshold value stored in advance, and when the predetermined means determines that the predetermined data is normal, A history information update process for storing and storing the predetermined data in the history information is performed, and when the determination unit determines that the predetermined data is not normal, the predetermined data is stored in the history information. It is characterized by comprising history information updating means for stopping subsequent history information update processing after being held.

  According to this invention, when it is determined that the predetermined data is normal, the predetermined data acquired by the data acquisition means can be stored and retained in the history information. Thereby, when a failure occurs in the optical transceiver, the cause of the failure can be accurately grasped by referring to the history information. On the other hand, if it is determined that the predetermined data is not normal, after the predetermined data acquired by the data acquisition means is stored and retained in the history information, the history information update process performed thereafter is stopped. Can be made. As a result, even when a limit is set on the number of predetermined data to be stored as history information, history information updated in a predetermined period before the occurrence of a failure can be secured, thereby reducing the memory capacity. Can do.

In the optical transceiver of the present invention, a failure detection state in which a failure detection signal indicating whether or not a failure has been detected is set to a failure detection state when the determination unit determines that the predetermined data is not normal The history information may be updated based on an update prohibition signal acquired from the setting unit and an external management device having a function of outputting to the optical transceiver an update prohibition signal indicating whether or not to prohibit the history information update process. and a determining update inhibiting condition determining means for determining whether a forbidden updated prohibited state, the history information updating means, when a failure detection signal by failure detection state setting means is set to the failure detection state, or When the update prohibition signal is determined to be in the update prohibition state by the update prohibition state determination means, it is preferable to stop the history information update process. The history information update unit restarts the history information update process when the failure detection signal is set to the non-failure detection state and the update prohibition signal is set to the non-update prohibition state.

In this way, when it is determined that the predetermined signal is not normal and the failure detection signal is set to the failure detection state, or the update prohibition signal acquired from the external management device is in the update prohibition state. If it is determined, the history information update process performed by the optical transceiver can be stopped. As a result, even when a limit is set on the number of predetermined data to be stored as history information, history information updated in a predetermined period before the occurrence of a failure can be secured, thereby reducing the memory capacity. Can do. In addition, since the history information update process can be stopped based on the update prohibition signal acquired from the external management device, the management device side is before the occurrence of the failure even after the failure in the optical transceiver is recovered. By referring to the history information updated during a predetermined period, it is possible to accurately grasp the cause of the failure.

  In the optical transceiver of the present invention, the failure detection state setting unit causes the failure detection signal to be set to a non-failure detection state when the update prohibition state determination unit determines that the predetermined signal is in the update prohibition state. Is preferred.

  In this way, since the failure detection signal can be set to the non-failure detection state while the predetermined signal acquired from the external management device is in the update prohibited state, it is then acquired from the external management device. When it is determined that the predetermined signal is in the non-update prohibited state, the history information update process can be resumed immediately.

In the optical transceiver of the present invention, the predetermined data, the bias current of the light emitting element, the operating temperature of the light emitting element, the operating temperature of the optical transceiver, the light output level of the optical transceiver, the optical transceiver optical input level of the optical transceivers It is preferable that either the power supply voltage or the bias voltage of the light receiving element is included . Thus, even when a failure peculiar to the optical transceiver occurs, the cause of the failure can be accurately grasped.

  According to the optical transceiver of the present invention, it is possible to accurately grasp the cause of the failure that has occurred in the optical transceiver.

  Embodiments of an optical transceiver according to the present invention will be described below with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  First, FIG. 1 is a diagram illustrating a system configuration of an optical transceiver management system 1 in the embodiment. As shown in FIG. 1, the optical transceiver management system 1 includes optical transceivers 10A, 10B,..., And a management device 20 operated by a manager (user) of the optical transceiver. In the following description, the optical transceivers 10A, 10B,... Will be referred to as the optical transceiver 10 unless otherwise described separately. When a failure occurs in any of the optical transceivers 10, the optical transceiver management system 1 stores and holds various status data (predetermined data) acquired in the optical transceiver 10 in which the failure has occurred in history information. A function of temporarily stopping the update process to be performed. In the optical transceiver management system 1 having such a function, when a failure occurs in the optical transceiver 10, the management device 20 side refers to the history information before the failure occurrence, thereby accurately grasping the cause of the failure. It has the feature that it can do. Details of the situation data will be described later.

  Next, the optical transceiver 10 shown in FIG. 1 will be described. The optical transceiver 10 is an optical transceiver module with a built-in CPU, and is configured based on, for example, the GBIC (GigaBit Interface Converter) standard.

  Here, the hardware configuration of the optical transceiver 10 will be described with reference to FIG. As shown in FIG. 2, the optical transceiver 10 includes a CPU 101, a memory 102, a receiving device 103, a transmitting device 104, an A / D conversion device 105, and a communication interface 106. They are connected by a bus 107.

  The CPU 101 controls each device connected via the bus 107 by executing various programs stored in the memory 102.

  The memory 102 includes a ROM (Read Only Memory) 102A, a RAM (Random Access Memory) 102B, and an EEPROM (Electrically Erasable Programmable Read Only Memory) 102C. The ROM 102A stores various programs executed by the CPU 101. The RAM 102B temporarily stores programs executed by the CPU 101 and data, and is used as a work area for the CPU 101. The EEPROM 102C has a threshold storage area C1 and a history information update area C2.

  Stored in the threshold storage area C1 is a threshold of status data related to the operating status and environmental status (hereinafter referred to as the operating environmental status) of each unit provided in the optical transceiver 10. The status data includes, for example, a semiconductor laser (LD) laser bias current, a semiconductor laser operating temperature, an optical transceiver operating temperature, an optical transceiver optical output level, an optical transceiver optical input level, and an optical transceiver power supply voltage. And an avalanche photodiode (APD) bias voltage. Further, the threshold value of the situation data includes an upper limit threshold value and a lower limit threshold value. The threshold value of the situation data is set to the situation data when the value of the situation data is equal to or higher than the upper limit threshold value corresponding to the situation data, or when the value of the situation data is equal to or lower than the lower limit threshold value corresponding to the situation data. The corresponding situation is a value for determining that there is a failure occurrence situation.

  Each status data acquired in the past is stored as history information in the history information update area C2. The number of status data items stored as history information may be set as appropriate depending on the memory capacity and the characteristics of the failure content. For example, when status data is acquired every 5 [msec], 100 status data acquired in the latest 500 [msec] may be stored as history information.

  The receiving device 103 is a receiving module that converts an optical signal received from the outside into an electric signal. The receiving apparatus 103 includes, for example, a DC-DC converter, an APD bias control circuit, an avalanche photodiode (light receiving element), a front-end amplifier (for example, a transimpedance amplifier), an automatic gain control amplifier, and a buffer amplifier. . The APD bias control circuit changes the bias value according to the function of keeping the multiplication factor of the avalanche photodiode constant when the temperature (environmental temperature) of the avalanche photodiode changes or the input light intensity. It has a function. Hereinafter, the operation of the receiving apparatus 103 will be briefly described. First, light input from the outside is converted into a bias voltage of several tens of volts by a DC-DC converter. The converted bias voltage is converted to a reverse bias by the APD bias control circuit and input to the avalanche photodiode. Next, the signal photoelectrically / electrically converted by the avalanche photodiode is subjected to current / voltage conversion by the front-end amplifier, waveform-shaped by the automatic gain control amplifier, and then output as a complementary signal from the buffer amplifier.

  The transmission device 104 is a transmission module that converts an electrical signal into an optical signal and transmits the optical signal to the outside. The transmission device 104 includes, for example, an LD driver, a semiconductor laser (light emitting element), a Peltier element (TEC), a photodiode (PD: Photo Diode), and an APC circuit. The LD driver drives the semiconductor laser based on the input electric signal. The photodiode monitors the intensity of the output light from the semiconductor laser. The APC circuit controls based on the monitor signal received from the photodiode so that the emitted light intensity of the semiconductor laser is kept constant. The Peltier element is controlled so that the temperature of the semiconductor laser is kept constant.

  The A / D conversion device 105 converts the status data regarding the operating environment status of each unit provided in the optical transceiver 10 into a digital value, and stores the converted status data in a temporary storage register in the CPU 101.

  The communication interface 106 is an interface for connection with the management apparatus 20 and mediates exchange of data performed between the optical transceiver 10 and the management apparatus 20.

  Next, the functional configuration of the optical transceiver 10 will be described with reference to FIG. As shown in FIG. 3, the optical transceiver 10 includes a data acquisition unit (data acquisition unit) 11, a determination unit (determination unit) 12, a history information update unit (history information update unit) 13, and a failure detection signal setting unit. (Failure detection state setting means) 14 and an update prohibition state determination unit (update prohibition state determination means) 15.

  The data acquisition unit 11 acquires status data (predetermined data) regarding the operating environment status of each unit provided in the optical transceiver 10. Specifically, the data acquisition unit 11 includes, for example, a semiconductor laser bias current, a semiconductor laser operating temperature, an optical transceiver operating temperature, an optical transceiver optical output level, an optical transceiver optical input level, and an optical transceiver power supply. Each status data such as the voltage and the bias voltage of the avalanche photodiode is acquired every predetermined period (for example, 5 [msec]). Further, the data acquisition unit 11 converts each acquired situation data into a digital value by the A / D conversion device 105, and stores the converted situation data in a temporary storage register in the CPU 101.

  Based on the situation data acquired by the data acquisition unit 11 and the threshold value corresponding to the situation data, the determination unit 12 determines whether the operating environment status of each unit provided in the optical transceiver 10 is normal. Determine. Specifically, the determination unit 12 compares each situation data stored in the temporary storage register in the CPU 101 with a threshold corresponding to each situation data stored in the threshold storage area C1 of the EEPROM 102C. If the situation data is equal to or greater than the upper threshold corresponding to the situation data, or if the situation data is less than or equal to the lower threshold corresponding to the situation data, the operating environment situation corresponding to the situation data is not normal (abnormal Is determined). On the other hand, when the situation data is less than the upper limit threshold corresponding to the situation data and the situation data exceeds the lower limit threshold corresponding to the situation data, the determination unit 12 operates the operating environment corresponding to the situation data. Determine that the situation is normal.

  When the determination unit 12 determines that each operating environment situation is normal, the history information update unit 13 converts the latest situation data acquired by the data acquisition unit 11 into history information corresponding to the situation data. A history information update process for storing and holding in a memory (not shown) is performed. On the other hand, when the determination unit 12 determines that each operating environment status is not normal, the history information update unit 13 sets the latest status data acquired by the data acquisition unit 11 to the history information corresponding to the status data. Then, the history information update process performed thereafter is stopped. The history information update unit 13 determines that the update prohibition signal is in an OFF state by an update prohibition state determination unit 15 to be described later after the determination unit 12 determines that each operating environment situation is not normal, and When it is determined that a failure detection signal to be described later is in an OFF state, history information update processing for storing and holding the latest status data acquired by the data acquisition unit 11 in history information corresponding to the status data Resume. The history information update process described above includes a process of storing and registering status data in the history information, and a process of storing and updating status data in the history information (the same applies hereinafter).

  The failure detection signal setting unit 14 sets the failure detection signal to an ON state (failure detection state indicating that a failure has been detected) when the determination unit 12 determines that each operating environment state is not normal. Here, the failure detection signal is a signal that is switched from the OFF state (non-failure detection state) to the ON state (failure detection state) when the determination unit 12 detects a failure. After the failure detection signal is set to the ON state, the failure detection signal setting unit 14 outputs the failure detection signal when the update prohibition state determination unit 15 described later determines that the update prohibition signal is in the ON state. Set to OFF state.

  The update prohibition state determination unit 15 determines whether or not updating history information is prohibited based on the update prohibition signal acquired from the management device 20. More specifically, the update prohibition state determination unit 15 determines whether or not the update prohibition signal acquired from the management device 20 is in an ON state (update prohibition state in which history information is prohibited to be updated). . Here, the update prohibition signal is a signal transmitted from the management apparatus 20 to the optical transceiver 10, and is set to the ON state (update prohibition state) when the history information update in the optical transceiver 10 is prohibited, and the history information is updated. Is permitted to be in an OFF state (non-update prohibited state).

  Next, the functional configuration of the management apparatus 20 will be described with reference to FIG. As illustrated in FIG. 3, the management apparatus 20 includes a failure detection state determination unit (failure detection state determination unit) 21 and an update prohibition state setting unit (update prohibition state setting unit) 22.

  The failure detection state determination unit 21 determines whether a failure is detected in the optical transceiver 10 based on the failure detection signal acquired from the optical transceiver 10. Specifically, the failure detection state determination unit 21 determines whether or not the failure detection signal acquired from the optical transceiver 10 is in the ON state (failure detection state indicating that a failure has been detected).

  The update prohibition state setting unit 22 sets the update prohibition signal to the update prohibition state when the failure detection state determination unit 21 determines that the failure detection signal is in the fault detection state. More specifically, the update prohibition state setting unit 22 sets the update prohibition signal to the ON state when the failure detection state determination unit 21 determines that the failure detection signal is in the ON state. Further, when the update prohibition state setting unit 22 receives a predetermined signal for releasing the update prohibition state, the update prohibition state setting unit 22 sets the update prohibition signal to a non-update prohibition state that permits the update of history information. Specifically, the update prohibition state setting unit 22 outputs an update prohibition signal when receiving a predetermined signal for canceling the update prohibition state transmitted based on an operation instruction from the administrator (user). Set to OFF state.

  Next, the flow of signals in the optical transceiver 10 of the optical transceiver management system 1 will be described with reference to the timing chart shown in FIG.

  FIG. 5A is a diagram illustrating a waveform of the first situation data signal acquired by the data acquisition unit 11. FIG. 5B is a diagram illustrating a waveform of the second situation data signal acquired by the data acquisition unit 11. Note that a1 and b1 shown in FIGS. 5A and 5B are waveforms indicating the upper threshold signal corresponding to each situation data, and a2 and b2 indicate the lower threshold signal corresponding to each situation data. It is a waveform. FIG. 5C is a diagram illustrating a waveform of a failure detection signal output by the failure detection signal setting unit 14. FIG. 4D is a diagram illustrating a waveform of the update prohibition signal acquired from the management apparatus 20. FIG. 5E is a diagram showing a sample signal generated based on the master clock of the optical transceiver 10. As shown in FIG. 5E, the sample signal is output by alternately repeating the low level signal and the high level signal at predetermined intervals. The data acquisition unit 11 acquires each status data every time the sample signal is switched from the low level to the high level, and the history information update unit 13 acquires each status data acquired by the data acquisition unit 11 as each status data. Is stored in history information corresponding to.

  First, at time t1, when the value of the first situation data signal reaches the value of the upper threshold signal a1 (FIG. 5A), the failure detection signal setting unit 14 changes the failure detection signal from the OFF state to the ON state. The setting is made (FIG. 5C). As a result, the history information update unit 13 stores and holds the latest status data acquired by the data acquisition unit 11 in the history information corresponding to the status data, and thereafter updates the history information. Stop processing. That is, each situation data acquired after time t1 is not stored in the history information.

  Next, when the update prohibition signal acquired from the management apparatus 10 is switched from the OFF state to the ON state at time t2 (FIG. 5D), the failure detection signal setting unit 14 changes the failure detection signal from the ON state to the OFF state. (FIG. 5C).

  Next, at time t3, the value of the first situation data signal converges between the value of the lower threshold signal a1 and the value of the upper threshold signal a1 (FIG. 5 (a)). At time t3, the failure that has occurred in the optical transceiver 10 has been resolved, but the history information update unit 13 continues to stop the history information update processing after time t3.

  Next, when the update prohibition signal acquired from the management device 10 is switched from the ON state to the OFF state at time t4 (FIG. 5D), the history information update unit 13 updates the latest information acquired by the data acquisition unit 11. The history information update process for storing and holding each status data in the history information corresponding to each status data is resumed. That is, after the time t4, the latest status data is stored in the history information.

  As described above, since the latest status data is not stored in the history information from time t1 to time t4, the status data within a predetermined period acquired before the failure occurrence at time t1 is used as history information. Can be held as. Therefore, the management device 20 side can accurately grasp the cause of the failure by referring to the status data acquired before the failure occurs.

  Next, with reference to the flowchart shown in FIG. 6, the operation of history information update processing of the optical transceiver 10 performed in the optical transceiver management system 1 will be described.

  This history information update process is a process that is repeatedly performed every predetermined sample period (for example, 5 [msec]) after the optical transceiver 10 is activated and the initial process is completed, and the supply of power to the optical transceiver 10 is performed. Exit when stops.

  First, when the sample signal is switched from the low level to the high level, the data acquisition unit 11 of the optical transceiver 10 provides status data (for example, a bias current of the semiconductor laser) regarding the operating environment status of each unit provided in the optical transceiver 10. , Semiconductor laser operating temperature, optical transceiver operating temperature, optical transceiver optical output level, optical transceiver optical input level, optical transceiver power supply voltage, and avalanche photodiode bias voltage) The data is converted into a digital value and then stored in a temporary storage register in the CPU 101 (step S1).

  Next, the determination unit 12 of the optical transceiver 10 compares each situation data stored in the temporary storage register in the CPU 101 with a threshold corresponding to each situation data stored in the threshold storage area C1 of the EEPROM 102C. Thus, it is determined whether or not the situation data is equal to or higher than the upper threshold corresponding to the situation data, or whether or not the situation data is equal to or lower than the lower threshold corresponding to the situation data (step S2).

  In this determination, when it is determined that the situation data is less than the upper threshold corresponding to the situation data and the situation data is greater than the lower threshold corresponding to the situation data (step S2; NO), the optical transceiver The history information update unit 13 of 10 stores the latest status data stored in the temporary storage register in the CPU 101 in the history information corresponding to the status data (step S3), and ends the history information update process. To do.

  On the other hand, when it is determined in step S2 that the situation data is greater than or equal to the upper threshold corresponding to the situation data, or the situation data is less than or equal to the lower threshold corresponding to the situation data (step S2; YES) ), The failure detection signal setting unit 14 of the optical transceiver 10 sets the failure detection signal to the ON state (step S4).

  Next, when the sample signal is switched from the low level to the high level, the data acquisition unit 11 of the optical transceiver 10 acquires each status data again, converts each acquired status data into a digital value, and then stores the status data in the CPU 101. Is stored in the temporary storage register (step S5).

  Next, the update prohibition state determination unit 15 of the optical transceiver 10 determines whether or not the update prohibition signal acquired from the management device 20 is in an ON state (step S6).

  If it is determined in this determination that the update prohibition signal acquired from the management device 20 is in the ON state (step S6; YES), the failure detection signal setting unit 14 of the optical transceiver 10 sets the failure detection signal to the OFF state. (Step S7), and the process proceeds to Step S5.

  On the other hand, when it is determined in step S6 that the update prohibition signal acquired from the management device 20 is in the OFF state (step S6; NO), the history information update unit 13 of the optical transceiver 10 receives the failure detection signal. It is determined whether or not it is in an ON state (step S8).

  If it is determined that the failure detection signal is in the ON state (step S8; YES), the process proceeds to step S5.

  On the other hand, if it is determined in step S8 that the failure detection signal is OFF (step S8; NO), the history information update unit 13 of the optical transceiver 10 is stored in the temporary storage register in the CPU 101. Each latest situation data is stored in the history information corresponding to each situation data (step S3), and the history information update process is terminated.

  As described above, when it is determined that the operation status and environmental status of each unit in the optical transceiver 10 are normal, the latest status data acquired by the data acquisition unit 11 is included in the status data. Since it is stored and stored in the corresponding history information, when a failure occurs in each part of the optical transceiver, the cause of the failure can be accurately grasped based on the history information updated before the failure occurs. .

  In addition, when it is determined that the operation status or environmental status of each unit in the optical transceiver is not normal and the failure detection signal is set to the failure detection state, or the update prohibition signal acquired from the management device 20 is If it is determined that the update is prohibited, the history information update process performed by the optical transceiver 10 is stopped. Therefore, even if a limit is set on the number of status data stored as history information, a failure occurs. History information updated in the previous predetermined period can be secured, and the memory capacity can be reduced.

  Further, in order to stop the history information update process performed in the optical transceiver 10 based on the content of the update prohibition signal acquired from the management device 20, the management device 20 side is after the failure in the optical transceiver 10 is recovered. In addition, the cause of the failure that has occurred in the optical transceiver 10 can be accurately grasped based on the history information updated in a predetermined period before the failure.

  In addition, when it is determined that the update prohibition signal acquired from the management device 20 is in the update prohibition state, the failure detection signal setting unit 14 acquires the failure detection signal from the management device 20 in order to set the failure detection signal to the non-failure detection state. When it is determined that the update prohibition signal is in the non-update prohibition state, the history information update process performed in the optical transceiver 10 can be resumed immediately.

  In the above-described embodiment, the GBIC standard is adopted as the optical transceiver module. However, the standard of the optical transceiver module is applicable to, for example, the SFP (Small Form Factor Pluggable) standard.

It is a figure which shows the system configuration | structure of the optical transceiver management system in embodiment of invention. It is a block diagram which shows the hardware constitutions of the optical transceiver shown in FIG. It is a block diagram which shows the function structure of the optical transceiver shown in FIG. It is a block diagram which shows the function structure of the management apparatus shown in FIG. It is a timing chart which shows the flow of the signal in an optical transceiver. It is a flowchart which shows detailed operation | movement of an optical transceiver management system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical transceiver management system, 10A, 10B ... Optical transceiver, 11 ... Data acquisition part, 12 ... Determination part, 13 ... History information update part, 14 ... Fault detection signal setting , 15 ... Update prohibition state determination unit, 101 ... CPU, 102 ... Memory, 103 ... Receiving device, 104 ... Transmitting device, 105 ... A / D conversion device, 106 · ..Communication interface, 107... Bus, 20.

Claims (2)

An optical transceiver,
A light emitting element that converts an electrical signal into an optical signal;
A light receiving element that converts an optical signal into an electrical signal;
Data acquisition means for acquiring predetermined data;
Determination means for determining whether or not the predetermined data is normal based on the predetermined data acquired by the data acquisition means and a predetermined threshold stored in advance;
When the determination unit determines that the predetermined data is normal, a history information update process for storing and storing the predetermined data in history information is performed, and the determination unit stores the predetermined data. If it is determined that it is not normal, after the predetermined data is stored and retained in the history information, history information update means for stopping the subsequent history information update process;
A failure detection state setting unit that sets a failure detection signal indicating whether or not a failure is detected when the predetermined data is determined to be normal by the determination unit;
Updating the history information based on the update prohibition signal acquired from an external management apparatus having a function of outputting an update prohibition signal indicating whether to prohibit the history information update processing to the optical transceiver; Update prohibition state determination means for determining whether or not it is a prohibited update prohibition state,
The predetermined data includes a bias current of the light emitting element, an operating temperature of the light emitting element, an operating temperature of the optical transceiver, an optical output level of the optical transceiver, an optical input level of the optical transceiver, a power supply voltage of the optical transceiver, and Including any of the bias voltages of the light receiving elements,
The history information update unit is configured such that when the failure detection signal is set in a failure detection state by the failure detection state setting unit, or the update prohibition signal is in the update prohibition state by the update prohibition state determination unit. If determined, stop the history information update process,
The failure detection state setting means sets the failure detection signal when the update prohibition signal is determined to be in the update prohibition state by the update prohibition state determination means after setting the failure detection signal to the failure detection state. Is set to a non-failure detection state. The history information update means restarts the history information update process when the failure detection signal is set to the non-failure detection state and the update prohibition signal is set to a non-update prohibition state. The optical transceiver according to claim 1.

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