JP2019113436A - Optical power meter - Google Patents

Abstract

To provide an optical power meter with which it is possible to acquire measured data that satisfies a trigger condition and measured data needed for analysis before and after it, without increasing storage capacity.SOLUTION: Provided is an optical power meter comprising: an optical power measurement unit for measuring the optical power of received light; a data management unit for storing the measured optical power as measured data in a ring buffer format; a trigger management unit for accepting the setting of a trigger condition that is a condition for the measured data of optical power and a trigger position indicating the position of measured data, in a stored measured data group, that satisfies the trigger condition; and a trigger control unit which, when it is detected that measured data that satisfies the trigger condition is stored at the trigger position in a ring buffer, causes the updating of the ring buffer to be stopped.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical power meter, and more particularly to an optical power meter having a trigger function.

  The optical power meter is a device that receives the light to be measured via an optical fiber or the like to measure the optical power. Here, the optical power is a physical quantity measured when evaluating characteristics such as light output, loss, reflection, etc. of a device or transmission path, and W as a unit or dBm of logarithmic display based on 1 mW is a unit. used.

  FIG. 9 is a block diagram showing a functional configuration of the conventional optical power meter 500. As shown in FIG. As shown in the figure, the optical power meter 500 includes a light receiving unit 510 for receiving the light to be measured, an optical power measuring unit 520 for measuring the power of the received light, and data management for storing the measured optical power as measurement data. A communication unit 540 for communicating with the external device 560 is provided.

  The external device 560 is a device that acquires measurement data from the optical power meter 500 and analyzes a change in optical power or the like, and can be configured by a PC or the like on which analysis software is installed.

JP 2012-78281 A

  Conventionally, the optical power meter 500 mainly uses the method of measuring the optical power in a single shot, and it has not been common to continuously acquire measurement data and analyze in time series. Therefore, the data management unit 530 aims to temporarily store measurement data, and accumulation and analysis of the measurement data are performed by transmitting the measurement data to the external device 560 after the measurement is completed and performing the measurement data on the external device 560 side. It has become.

  Also, from the viewpoint of portability, cost, etc., the data storage area of the data management unit 530 is restricted in capacity, and adopts a ring buffer structure. That is, new data is overwritten in order from old data.

  The importance of time series analysis of measurement data in the optical power meter 500 is increasing with the spread of optical communication in recent years, and in particular, analysis of a group of measurement data before and after measurement data satisfying a predetermined trigger condition is emphasized.

  However, when measurement is continuously performed with the optical power meter 500 for a predetermined period and measurement data is transmitted to the external device 560 after the measurement is completed, even if measurement data satisfying the trigger condition is generated during the measurement period, transmission is performed. There is no guarantee that the measured data group contains measured data that meets the trigger condition.

  For example, it may happen that the measurement data satisfying the trigger condition is overwritten by the old data. In addition, even if the measurement data that satisfies the trigger condition is included, it may happen that the measurement data before and after the analysis necessary can not be obtained sufficiently.

  Increasing the storage capacity of the data management unit 530 increases the possibility of acquiring measurement data that satisfies the trigger condition and measurement data before and after analysis, but the portability of the optical power meter 500 is impaired, and the cost increases. Will lead to

  Therefore, an object of the present invention is to make it possible to obtain measurement data satisfying trigger conditions and measurement data before and after analysis necessary for an optical power meter without increasing storage capacity.

In order to solve the above problems, an optical power meter according to an aspect of the present invention includes an optical power measurement unit that measures the power of received light, and data management that stores the measured optical power as measurement data in a ring buffer format. , A trigger management unit that receives a trigger condition that is a condition for measurement data of optical power, and a trigger position setting that indicates a position of measurement data that satisfies the trigger condition in the measurement data group to be stored; And a trigger control unit for stopping updating of the ring buffer when it is detected that data is stored in a trigger position in the ring buffer.
Here, the trigger control unit refers to the ring buffer every time measurement data is stored in the data management unit, and determines whether measurement data satisfying the trigger condition is stored at the trigger position. it can.
Further, when the measurement data satisfying the trigger condition is stored in the data management unit, the trigger control unit moves the measurement data satisfying the trigger condition to the trigger position every time when the measurement data is subsequently stored. Can be determined.
In addition, when the received light is CHOP light, the FFT operation unit Fourier-transforms the measurement result of the light power measurement unit in a predetermined frame, and the FFT operation unit is used for modulation of the CHOP light. These frequency components may be extracted and stored in the data management unit as measurement data.

  According to the present invention, in the optical power meter, measurement data satisfying the trigger condition and measurement data before and after the analysis can be obtained without increasing the storage capacity.

It is a block diagram which shows the function structure of the optical power meter which concerns on this embodiment. It is a figure explaining the setting example of a trigger position. It is a flowchart explaining the 1st operation example of a trigger control part. It is a figure explaining determination of a trigger condition and a trigger position. It is a figure explaining the measurement data group obtained by the optical power meter of this embodiment. It is a flowchart explaining the 2nd operation example of a trigger control part. It is a block diagram explaining functional composition of an optical power meter concerning a modification. It is a figure explaining the light power measurement process of CHOP light. It is a block diagram which shows the function structure of the conventional optical power meter.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a functional configuration of the optical power meter 100 according to the present embodiment. As shown in the figure, the optical power meter 100 includes a light receiving unit 110 for receiving the light to be measured, an optical power measuring unit 120 for measuring the power of the received light, and a ring buffer type measuring the measured optical power as measurement data. A data management unit 130 to be stored, a communication unit 140 that communicates with the external device 200, a trigger management unit 150, and a trigger control unit 160 are provided.

  The external device 200 is a device that acquires measurement data from the optical power meter 100 and analyzes a change in optical power or the like, and can be configured by a PC or the like on which analysis software is installed.

  The trigger management unit 150 receives settings of trigger conditions and trigger positions from the operator. The setting of the trigger condition and the trigger position can be received, for example, via a button or the like included in the optical power meter 100. Alternatively, it may be accepted via the external device 200.

  The trigger condition is a condition for measurement data of optical power, and various conditions can be set. The measurement data satisfying the trigger condition and the measurement data before and after are the final storage target data group. Here, the measurement data before and after means at least one of the measurement data group before the measurement data satisfying the trigger condition and the measurement data group after the measurement data satisfying the trigger condition, and based on the setting received from the operator .

  The trigger condition can be, for example, not less than a designated threshold and not more than a designated threshold. In addition, it is possible to make transition from below threshold to above threshold and transition from above threshold to below threshold. Furthermore, the rise, fall, and change rate of the measurement data waveform may be equal to or higher than the reference value, or the measurement data waveform may draw a specific pattern.

  Here, measurement data that satisfies the trigger condition is referred to as trigger data. Also, (old) measurement data before trigger data is referred to as previous data, and (new) measurement data after trigger data is referred to as post data.

  The trigger position is information indicating the position of trigger data in the stored measurement data group. For example, as shown in FIG. 2A, the position of trigger data can be set at a ratio to the entire stored measurement data determined by the size of the ring buffer. The example of this figure is a setting which stores trigger data in the position of 30% from the old one. In this case, the ratio between the number of previous data and the number of subsequent data is approximately 3: 7.

  Further, as shown in FIG. 2B, the positions of the trigger data may be set in the order from the head to the trigger data. The example of this figure is a setting which stores trigger data in the 8000th position from the old one. Of course, it may be set in order from the rear end, or may be set by the number of front data or rear data.

  In addition, as shown in FIG. 2C, the position of the trigger data may be set in a word. The example of this figure is the setting which stores trigger data in the center position of the whole storing measurement data. The wording can be head, end, first half, second half, etc. However, setting of the trigger position is not limited to the above example.

  The trigger control unit 160 determines the trigger condition of the measurement data stored in the data management unit 130 based on the setting received by the trigger management unit 150, and at the stage when the trigger data is arranged at the trigger position, the data management unit Control is performed so that the 130 ring buffers are not updated. Specifically, the light power measurement unit 120 is controlled to end the measurement. Alternatively, the data management unit 130 may be controlled so that measurement data is not stored in the ring buffer even if measurement in the optical power measurement unit 120 is continued.

  Next, a first operation example of the trigger control unit 160 will be described with reference to the flowchart of FIG. In addition, it is assumed that the trigger management unit 150 receives the setting of the trigger condition and the trigger position from the operator in advance. In addition, it is assumed that measurement termination conditions are determined based on the measurement time, the number of measurements, and the like.

  Prior to the start of measurement, the trigger control unit 160 acquires a trigger condition from the trigger management unit 150 (S101). Also, the trigger position is acquired (S102). The acquired trigger position is converted, for example, in order from the rear end (latest data) in the entire measurement data to be stored.

  For example, when the acquired trigger position is set at a ratio to the entire stored measurement data, the order is converted from the rear end based on the number of storable measurement data. Even when the acquired trigger position is set in a word, it is converted to the order from the rear end based on the number of storable measurement data. For example, in the first half, as an example, it is possible to set an order corresponding to about 3/4 of the whole from the rear end.

  When measurement is started, every time measurement data is stored in the data management unit 130 (S103: Yes), the measurement data stored in the ring buffer of the data management unit 130 is referenced (S104), and trigger conditions are set at the trigger position. It is determined whether there is trigger data that satisfies the condition (S105). The trigger positions can be easily referred to because they are converted in order from the rear end.

  For example, in the case where the trigger position is set at the position as shown in FIG. 4A, the trigger position is not satisfied even if the newly stored measurement data is trigger data satisfying the trigger condition. It is determined that no trigger data satisfying the trigger condition exists at the trigger position (S105: No). If the measurement is not completed (S106: No), it waits for the next measurement data to be stored in the data management unit 130 (S103).

  Since the ring buffer structure is adopted, trigger data will approach the trigger position each time measurement data is stored. Then, as shown in FIG. 4B, when the trigger data reaches the trigger position, it is determined that trigger data satisfying the trigger condition exists at the trigger position in the ring buffer reference (S104) (S105: Yes), The update of the buffer is stopped (S107). That is, it instructs the light power measurement unit 120 to stop the measurement, or instructs the data management unit 130 to stop storing the measurement data.

  Since the ring buffer of the data management unit 130 is not updated, the ring buffer holds the state where the measurement data group in which the trigger data is recorded at the trigger position is stored. That is, measurement data satisfying the trigger condition and measurement data before and after the analysis can be acquired without increasing the storage capacity.

  By outputting the measurement data group stored in the ring buffer to the external device 200 via the communication unit 140, for example, as shown in FIG. 5, the time-series data includes trigger data, previous data, and subsequent data. It is possible to perform time-series analysis of measurement data appropriately, because

  Next, a second operation example of the trigger control unit 160 will be described with reference to the flowchart of FIG. Acquisition of the trigger condition (S201) and acquisition of the trigger position (S202) are the same as in the first operation example. The acquired trigger positions are converted in order from the rear end (latest data) in the entire measurement data to be stored.

  When measurement is started, each time measurement data is stored in the data management unit 130 (S103: Yes), it is determined whether the newly stored measurement data satisfies the trigger condition (S204).

  If the newly stored measurement data does not satisfy the trigger condition (S204: No), if the measurement is not completed (S205: No), it waits for the next measurement data to be stored in the data management unit 130 (S203) .

  If the newly stored measurement data satisfies the trigger condition (S204: Yes), it is determined whether the newly stored measurement data satisfies the trigger position (S206). This is an allowance when the rear end is set as the trigger position. If it is determined that the trigger position is satisfied (S206: Yes), update of the ring buffer is stopped (S210). That is, it instructs the light power measurement unit 120 to stop the measurement, or instructs the data management unit 130 to stop storing the measurement data.

  When the newly stored measurement data does not satisfy the trigger position (S204: No), that is, when the trigger position is set to other than the rear end, every time measurement data is stored in the data management unit 130 (S207 Yes: The movement amount of trigger data is counted (S208). Here, each time measurement data is stored, the trigger data moves one by one to the front end side.

  Then, when the trigger data moves to the trigger position (S209: Yes), updating of the ring buffer is stopped (S210). Since the trigger position is converted in order from the rear end, it is possible to easily grasp the movement amount necessary for the trigger position.

  Since the ring buffer of the data management unit 130 is not updated, the ring buffer holds the state where the measurement data group in which the trigger data is recorded at the trigger position is stored.

  Next, a modification of the optical power meter of the present embodiment will be described. In the above-described optical power meter 100, since continuous light is assumed as the light to be measured, when CHOP light modulated at a predetermined frequency MF is used as the light to be measured, there is a possibility that the trigger determination of the optical power may not be performed correctly. There is.

  Therefore, the optical power meter 101 according to the modification is configured to correspond to CHOP light. FIG. 7 is a block diagram for explaining the functional configuration of the optical power meter 101. As shown in FIG. The same functional blocks as those of the above-described optical power meter 100 are denoted by the same reference numerals.

  As shown in the figure, the optical power meter 101 is provided with an FFT operation unit 170 between the light power measurement unit 120 and the data management unit 130 in addition to the above configuration. The operation of the trigger control unit 160 may be either the first operation example or the second operation example described above.

  As shown in FIG. 8A, the FFT operation unit 170 performs Fourier transform on the optical power measurement result of the CHOP of the modulation frequency MF in a predetermined frame unit. Then, the modulation frequency MF component is extracted, and as shown in FIG. 8B, the average light power in the frame period is stored in the data management unit 130 as measurement data. Thus, even if the light to be measured is CHOP light, the trigger control unit 160 can appropriately determine the trigger condition.

DESCRIPTION OF SYMBOLS 100 ... Optical power meter, 101 ... Optical power meter, 110 ... Light receiving part, 120 ... Optical power measurement part, 130 ... Data management part, 140 ... Communications part, 150 ... Trigger management part, 160 ... Trigger control part, 170 ... FFT Arithmetic unit, 200 ... external device

Claims (4)

An optical power measurement unit that measures the power of the received light;
A data management unit that stores the measured optical power as measurement data in a ring buffer format;
A trigger management unit that receives a trigger condition that is a condition for measurement data of optical power and a setting of a trigger position that indicates a position of measurement data that satisfies the trigger condition in the stored measurement data group;
A trigger control unit for stopping updating of the ring buffer when it is detected that measurement data satisfying a trigger condition is stored at the trigger position in the ring buffer;
An optical power meter characterized by comprising: The trigger control unit
The ring buffer is referred to each time measurement data is stored in the data management unit, and it is determined whether measurement data satisfying the trigger condition is stored in the trigger position. Optical power meter. The trigger control unit
When measurement data satisfying the trigger condition is stored in the data management unit, it is determined for each subsequent storage of measurement data whether measurement data satisfying the trigger condition has moved to the trigger position. The optical power meter according to claim 1. It further comprises an FFT operation unit,
When the received light is CHOP light, the FFT operation unit Fourier-transforms the measurement result of the light power measurement unit in a predetermined frame, extracts the frequency component used for modulation of the CHOP light, and measures The optical power meter according to any one of claims 1 to 3, wherein the data management unit stores the data as data.