JP5688988B2 - Optical pulse test equipment - Google Patents

Description

  The present invention relates to an optical pulse test apparatus (hereinafter referred to as OTDR), and more particularly to an OTDR used for confirming that an optical fiber has been laid correctly.

  To confirm whether or not the optical fiber laying work has been carried out correctly at construction sites such as new optical fiber laying and relocation of existing optical fiber due to construction such as buildings and road constructions, FIG. As shown, OTDR is used.

  In FIG. 8, the worker confirms that the worker is sequentially away from the worker point A and the worker who sequentially performs the fusion and bonding operations on each core wire of the multi-core optical fiber 1 including a plurality of core wires at the work point A. At point B, there are two hands of an operator who uses OTDR2 to check the status of laying work such as fusion and bonding.

  Then, each time the worker at the work point A performs the fusing and joining work for each of the cores of the optical fiber 1, the worker at the check point B has been properly fused and joined to the optical fiber 1. The confirmation based on the measurement result of OTDR2 of whether or not is obtained, and if it is confirmed that the fusion or bonding is correctly performed, the process proceeds to the fusion or bonding operation of the next core wire.

  In general, as the optical fiber cable 1, a multi-core optical fiber composed of a plurality of core wires is often used. Therefore, when laying such an optical fiber cable, the number of cores that need to be confirmed whether or not the fusion or bonding has been performed correctly is very large, such as 100 or 200. It is required to do. Especially in the case of obstacle relocation work, the work must be done in a short time.

  FIG. 9 is an example of a display screen of the OTDR 2 for confirming the work state at the work point A, (A) shows a state before work at the work point A, and (B) shows a state after work completion at the work point A. Is shown.

  In FIG. 9A, the end of the core of the optical fiber 1 indicates a 25 km point, and it can be confirmed that the fiber exists up to the 25 km point. This 25 km point is the pre-work point.

  On the other hand, in FIG. 9B, the end of the core of the optical fiber 1 indicates a 35 km point. That is, it can be confirmed that the core of the optical fiber 1 is further extended from the 25 km point to the 35 km point. This 35 km point will be the point after the work is completed.

  Patent Document 1 describes a method and an apparatus for measuring easily and accurately in a short time the confirmation of matching between the alignment order on the input side and the alignment order on the output side of each core wire of a multi-core optical fiber.

JP 2000-249624 A

  In laying optical fibers and rehabilitation work, it is necessary to fuse and bond a plurality of core wires in a short time. Therefore, every time the worker at the work point A performs fusion or bonding of one core wire, the operator at the confirmation point B is given an OTDR 2 indicating whether the fusion or bonding of the optical fiber 1 has been performed correctly. It is necessary to obtain confirmation by the measurement used and to move to the next core wire fusion and joining work as efficiently as possible in the shortest possible time.

  Therefore, in order to immediately respond to the confirmation request from the worker at the work point A, the worker at the current confirmation point B always performs measurement by OTDR2 and monitors the waveform displayed on the display screen. Is going.

  Therefore, there is a problem that the worker at the current confirmation point B cannot perform other work while the worker at the work point A is performing the fusion of the core wire or the joining work.

  The present invention solves such problems, and an object of the present invention is to provide an optical pulse test apparatus that enables an operator to shorten and reduce the time involved in OTDR measurement monitoring in confirming the fusion and bonding of optical fibers. It is to be realized.

In order to achieve the above object, the invention described in claim 1 of the present invention is:
Connected to one end of the optical fiber, enters the pulsed light, measures the pulsed light reflected from the other end of the optical fiber in the time domain, and sets the measurement result of the reflected pulsed light as the optical power on the vertical axis. In the optical pulse test apparatus configured to display as a measurement waveform on the display screen with the horizontal axis as the distance,
A checkpoint cursor setting unit for setting a checkpoint cursor at a desired distance position on the display screen;
A position comparison unit that compares the end position of the measurement waveform with the set position of the checkpoint cursor and outputs a detection signal when it detects that the end of the measurement waveform exceeds the set position of the checkpoint cursor When,
Based on this detection signal, a detection information output unit that outputs the fact to the outside,
Is provided.

The invention according to claim 2 is the optical pulse test apparatus according to claim 1,
The detection information output unit includes a detection information display generation unit that displays the fact on the display screen, a detection information voice output unit that outputs the fact as voice information, and sends the fact as electronic information to a predetermined destination via the network. It includes at least one of communication units for transmission.

The invention described in claim 3 is the optical pulse test apparatus according to claim 1 or 2, wherein
The optical fiber is a multi-core optical fiber.

  According to the present invention, the optical pulse test device itself compares the end position of the measured waveform with the set position of the checkpoint cursor, and detects that the end of the measured waveform exceeds the set position of the checkpoint cursor. Then, since the fact is output to the outside, the operator should confirm the display screen of the optical pulse test device and connect the next verification target core wire when the result is output, and confirm the installation of the multi-core optical fiber. You can work efficiently.

It is a principle block diagram of OTDR2. It is a block diagram which shows one Example of this invention. It is characteristic explanatory drawing of the measurement waveform displayed on the display part 25 of OTDR. It is explanatory drawing of the working point designation | designated method based on this invention. It is a flowchart explaining the flow of a process of the real-time measurement function of OTDR2. It is a flowchart explaining the flow of a process of fusion | bonding of the core wire using OTDR2, and joining work completion determination. It is an example of a concrete display screen of OTDR accompanying implementation of this invention. It is a conceptual explanatory diagram of conventional optical fiber fusion and joining work and confirmation work. It is a display screen example figure of OTDR2 for confirming the working state in the working point A.

  Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a principle block diagram of the above-described OTDR2. In FIG. 1, the pulsed light output from the laser diode 21 is incident on one end of the optical fiber 1 to be measured via the optical coupler 22.

  Rayleigh scattering occurs inside the optical fiber 1 to be measured, and part of it travels in the direction opposite to the traveling direction of the pulsed light and returns to the OTDR 2 as backscattered light. Further, the Fresnel reflected light generated at the connection point of the optical fiber 1 also returns to the OTDR 2.

  The reflected light that has returned to the OTDR 2 passes through the optical coupler 22 again, is input to the light receiving unit 23, and is converted into an electrical signal. The electrical signal converted and output from the light receiving unit 23 is input to the signal processing unit 24 and A / D converted at a timing synchronized with the generation of the pulsed light.

  The signal processing unit 24 measures the reflected light power in the optical fiber 1 based on the A / D-converted amplitude data, and from the time from when the pulsed light is output until the reflected light returns, in the optical fiber 1 Measure the position of the reflected light at. Further, the loss between the two points can be obtained from the difference in level of the reflected light power at each position in the optical fiber 1.

  In addition, since the signal level of reflected light is very small, noise is reduced by calculating | requiring an average by repeating several measurements.

  Further, the signal processing unit 24 generates a display screen for displaying the measurement result on the display unit 25 in the display form as shown in FIG.

  FIG. 2 is a block diagram showing an embodiment of the present invention, and shows a specific configuration example of the signal processing unit 24 of FIG. In FIG. 2, a reference clock generator 24a outputs a highly stable high-accuracy clock serving as a reference for the timing of the entire apparatus to each unit.

  The drive pulse generator 24b generates a pulse for intermittently driving the laser diode 21 based on the clock output from the reference clock generator 24a, and outputs the pulse to the laser diode drive controller 24c.

  The timing generation unit 24d generates a timing signal for A / D conversion of the electrical signal converted and output from the light receiving unit 23 at a timing synchronized with the generation of the pulsed light based on the clock output from the reference clock generation unit 24a. And output to the A / D converter 24e.

  The measurement calculation unit 24f measures, for example, pulse light reflected from the other end of the optical fiber 1 in the time domain based on output data related to the output signal of the light receiving unit 23 converted and output from the A / D conversion unit 24e. A predetermined calculation for calculating a desired measurement value such as an amplitude level at each position is performed.

  As described above, the display screen generation unit 24g uses the measurement result of the reflected pulsed light as a measurement waveform having the vertical axis as the optical power and the horizontal axis as the distance, and the display unit 25 in a desired display form as shown in FIG. Generate a display screen to display on

  The checkpoint cursor setting unit 24h generates and outputs a cursor set for a checkpoint at a desired distance position on the display screen of the display unit 25.

  The position comparison unit 24i compares the measurement waveform end of the reflected pulse light measurement result displayed with the optical power on the vertical axis and the distance on the horizontal axis, and the set position of the checkpoint cursor, and compares the measurement waveform When it is detected that the end has exceeded the set position of the checkpoint cursor, a detection signal is output.

  The detection information output unit 24j displays the detection information on the display screen based on the detection signal output from the position comparison unit 24i when the end of the measurement waveform exceeds the set position of the checkpoint cursor. It includes at least one of a generation unit, a detection information audio output unit that outputs the information as audio information, and a communication unit that transmits the information as electronic information to a predetermined destination via the network.

The operation of the OTDR configured as described above will be described.
FIG. 3 is a characteristic explanatory diagram of a measurement waveform displayed on the display unit 25 of the OTDR. A section C in (A) represents a section in which an optical fiber having a certain length exists. On the other hand, a section D in (B) represents a section in which the optical fiber exists in a state where another optical fiber is connected to the right end of the optical fiber shown in (A) and extended.

  That is, paying attention to the measurement waveform displayed on the display unit 25 of the OTDR, there is a feature that the right end of the measurement waveform is also extended in the right direction by connecting and extending another optical fiber to the right end of the optical fiber. is there.

  Therefore, in the present invention, using the characteristics of the measurement waveform displayed on the display unit 25 of such OTDR, as shown in FIG. 4, the optical fiber is fused or bonded on the display screen of the display unit 25. The check point cursor CC is set with the working point being set as a desired distance position, and the OTDR itself determines whether or not the right end of the measurement waveform exceeds the set check point cursor CC. It is configured to output to the outside.

  4A and 4B are explanatory diagrams of the working point designation method according to the present invention, in which FIG. 4A shows a state before the optical fiber is fused and joined, and FIG. 4B shows the state after the optical fiber is fused and joined. Show.

  The operator at the confirmation point B in FIG. 8 can perform any arbitrary operation in the right direction further than the right end of the optical fiber indicated by the measurement waveform (A) before the optical fiber is fused or joined at the work point A. A checkpoint cursor CC is set at the position. Note that in the state before the fusion or bonding operation is performed, no measurement signal is input to the display screen, and thus no measurement waveform is displayed.

  When fusion or bonding of the optical fiber starts at the work point A, a measurement waveform is displayed as shown in (A), the right end of the optical fiber is located on the left side of the check point cursor CC, and other light It shows the state where the fiber is not connected.

  When the fusion and joining operations of the optical fiber at the work point A are completed, the right end of the optical fiber moves to the right side of the check point cursor CC as shown in (B), and another optical fiber is connected. Represents.

  The operator at the confirmation point B in FIG. 8 visually confirms whether the right end of the optical fiber is located on the left or right side of the check point cursor CC based on the display result of the display unit 25 and melts the optical fiber. It is determined whether or not the wearing or joining work is completed, and the determination result is notified to the worker at the work point A.

  By the way, since a certain amount of work time is required for fusing and joining the optical fibers at the work point A, the worker at the confirmation point B sets the measurement target optical fiber (core wire) to OTDR2 and then melts it. It is desirable that other operations can be performed as described above until the wearing and joining operations are completed.

  Therefore, in the present invention, a position comparison unit 24i is provided for comparing the end of the measurement waveform of the measurement result of the pulsed light with the set position of the checkpoint cursor, and the end of the measurement waveform indicates the setpoint of the checkpoint cursor. A detection signal is output when it has been exceeded, and the end of the measurement waveform of the pulsed light measurement result exceeds the set position of the checkpoint cursor based on the detection signal output from the position comparison unit 24i. It includes at least one of a detection information display generation unit displayed on a display screen for output to the outside, a detection information audio output unit output as audio information, or a communication unit that transmits electronic information to a predetermined destination via a network A detection information output unit 24j is provided.

  Thereby, the operator at the confirmation point B monitors the display screen of the OTDR2 until the detection information output unit 24j outputs to the outside that the end of the measurement waveform has exceeded the set position of the checkpoint cursor. You can leave.

  Therefore, for example, other work such as report creation, and the provision of a plurality of OTDRs at the same confirmation point B to monitor the work point A, as well as the fusion of multiple systems of optical fibers such as other work points C and D, etc. The wearing and joining operations can be monitored in parallel, and the man-hours of the worker at the confirmation point B can be effectively utilized.

  FIG. 5 is a flowchart for explaining the processing flow of the real-time measurement function of the OTDR 2 and is used for monitoring the laying state of the optical fiber before the fusion of the core wire and the bonding work. The OTDR2 performs the OTDR measurement for a predetermined number of times (for example, 2 ^ 5) (step S1).

  Then, an analysis process for OTDR is performed based on the measurement result (step S2), and a drawing process of the waveform and the analysis result is executed (step S3).

  These series of processes are repeatedly executed until a stop request is input from the worker at the confirmation point B (step S4).

  The operator at the confirmation point B grasps the optical fiber laying state before the fusion of the core wire and the bonding work from the measurement result display screen displayed by the real-time measurement function, and the checkpoint cursor according to the present invention. Determine the position to set.

  FIG. 6 is a flowchart for explaining the flow of processing for core wire fusion and joining work completion determination using OTDR2. The worker at the confirmation point B refers to the measurement result display screen displayed by the real-time measurement function, and sets the checkpoint cursor to, for example, the position of the fusion work point A (step S1).

  Thereafter, the OTDR 2 performs OTDR measurement for a predetermined number of times (for example, 2 ^ 5) (step S2), performs OTDR analysis processing based on the measurement result (step S3), and terminates the position of the optical fiber. Is confirmed (step S4).

  Then, it is determined whether the end position of the optical fiber is longer (right side) or left side (left side) than the position of the checkpoint cursor set in step S1 (step S5). When the end position of the optical fiber is longer than the position of the checkpoint cursor (right side), the operator at the fusion work point A is notified that the work is completed (step S6), and then the waveform and the analysis result are displayed. Drawing processing is executed (step S7).

  On the other hand, when the end position of the optical fiber is not longer than the position of the checkpoint cursor (on the left side), step S6 is skipped and the waveform and analysis result drawing process is executed (step S7).

  These series of processes are repeatedly executed until a stop request is input from the worker at the confirmation point B (step S8).

  FIG. 7 is a view showing a specific display screen example of OTDR according to the embodiment of the present invention, and shows an example in which a 10 km optical fiber is fused to an end of an optical fiber having a total length of 25 km.

  FIG. 7A shows a situation before a 10 km optical fiber is fused. According to FIG. 7A, a reflection R1 representing the end of an optical fiber having a total length of 25 km is generated at the 25 km point of the measurement waveform, and the end position of the optical fiber having a total length of 25 km can be grasped. Note that the operator at the confirmation point B moves the check point cursor CC to the fusion work position behind the 25 km point during real-time measurement.

  In FIG. 7B, a confirmation screen CS is displayed on the display screen. If there is no problem, OK is pressed. The confirmation screen CS can be switched between display and non-display according to user settings. Then, the work completion check is turned ON.

  FIG. 7C shows a state in which an optical fiber having a length of 10 km is fused to an end of an optical fiber having a total length of 25 km. In FIG. 7C, a reflection R1 representing the fusion point of the optical fiber is generated at the 25 km point of the measurement waveform, and the end of the 10 km optical fiber fused to the end of the 25 km optical fiber is generated at the 35 km point. A reflection R2 representing a portion is generated.

  Here, the reflection R2 representing the end of the optical fiber to which the measurement waveform is fused is generated on the right side beyond the position of the checkpoint cursor CC. A beep is sounded to inform you by voice information.

  FIG. 7D shows that a reflection point R2 representing the end of the optical fiber with the measurement waveform fused is generated on the right side beyond the position of the check point cursor CC on the confirmation point B on the message screen MS. An example of informing the worker is shown.

  In the above-described embodiment, the worker is separated from the worker point A by a worker who sequentially performs fusion and bonding operations on each core wire of the multi-core optical fiber 1 composed of a plurality of core wires at the work point A. Although the example which is divided into two hands of the operator who confirms the status of the laying work such as fusion and bonding using the OTDR 2 at the confirmation point B is described, for example, the OTDR 2 used at the confirmation point B and the multi-core optical fiber 1 An optical switch switching unit configured to selectively connect the OTDR 2 and the core wire of the multi-core optical fiber 1 between them is provided, and the measurement result of OTDR 2 is transmitted to the worker at the work point A by e-mail or the like. After the worker at the work point A confirms the measurement result of the OTDR2, the optical switch switching unit is configured to be remotely controlled from the work point A. Joining work and them It is also possible to perform the confirmation work.

  In the above-described embodiment, an example of a multi-core optical fiber in which the optical fiber is composed of a plurality of cores has been described. However, the optical fiber can also be used for confirmation of fusion or bonding work of a single-core optical fiber.

  As described above, according to the present invention, it is possible to realize an optical pulse testing apparatus that can shorten and reduce the time involved in OTDR measurement monitoring when confirming the fusion and bonding of optical fibers. Can be used effectively.

1 Optical fiber 2 Optical pulse test equipment (OTDR)
21 laser diode 22 optical coupler 23 light receiving unit 24 signal processing unit 24a reference clock generation unit 24b drive pulse generation unit 24c laser diode drive control unit 24d timing generation unit 24e A / D conversion unit 24f measurement calculation unit 24g display screen generation unit 24h check Point cursor setting unit 24i Position comparison unit 24j Detection information output unit 25 Display unit

Claims (3)

Connected to one end of the optical fiber, enters the pulsed light, measures the pulsed light reflected from the other end of the optical fiber in the time domain, and sets the measurement result of the reflected pulsed light as the optical power on the vertical axis. In the optical pulse test apparatus configured to display as a measurement waveform on the display screen with the horizontal axis as the distance,
A checkpoint cursor setting unit for setting a checkpoint cursor at a desired distance position on the display screen;
A position comparison unit that compares the end position of the measurement waveform with the set position of the checkpoint cursor and outputs a detection signal when it detects that the end of the measurement waveform exceeds the set position of the checkpoint cursor When,
Based on this detection signal, a detection information output unit that outputs the fact to the outside,
An optical pulse test apparatus characterized by comprising: An optical pulse test apparatus used in the optical pulse test apparatus according to claim 1,
The detection information output unit includes a detection information display generation unit that displays the fact on the display screen, a detection information voice output unit that outputs the fact as voice information, and sends the fact as electronic information to a predetermined destination via the network. An optical pulse test apparatus comprising at least one of communication units for transmission.   3. The optical pulse test apparatus according to claim 1, wherein the optical fiber is a multi-core optical fiber.