JPH0454428A - Fault point searching method for branched optical fiber line - Google Patents
Fault point searching method for branched optical fiber lineInfo
- Publication number
- JPH0454428A JPH0454428A JP2164051A JP16405190A JPH0454428A JP H0454428 A JPH0454428 A JP H0454428A JP 2164051 A JP2164051 A JP 2164051A JP 16405190 A JP16405190 A JP 16405190A JP H0454428 A JPH0454428 A JP H0454428A
- Authority
- JP
- Japan
- Prior art keywords
- point
- fault
- line
- optical fiber
- branch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 49
- 238000000034 method Methods 0.000 title claims description 30
- 238000012545 processing Methods 0.000 claims abstract description 12
- 238000005259 measurement Methods 0.000 claims description 34
- 230000003287 optical effect Effects 0.000 claims description 19
- 238000012360 testing method Methods 0.000 claims description 11
- 230000003247 decreasing effect Effects 0.000 claims description 10
- 230000001186 cumulative effect Effects 0.000 claims description 3
- 230000005611 electricity Effects 0.000 claims 1
- 230000005540 biological transmission Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000004927 fusion Effects 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 210000000988 bone and bone Anatomy 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
Landscapes
- Testing Of Optical Devices Or Fibers (AREA)
- Optical Communication System (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、分岐を有する光フアイバ線路の故障点探索
方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for locating a fault point in an optical fiber line having branches.
従来より、光パルス発生器の発生する光パルスを被試験
光ファイバに入射し、反射してくる後方散乱光やフレネ
ル反射光を光・電変換し、さらに信号処理を施し、反射
点の距離と反射光強度との関係を反射波形として表示画
面上に描き出し、反射波形の後方散乱の減少点やフレネ
ル反射によるピーク点を、故障位置として、探索する方
法が広く用いられている。Conventionally, optical pulses generated by an optical pulse generator are incident on the optical fiber under test, the reflected backscattered light and Fresnel reflected light are converted into electrical signals, and then signal processing is performed to calculate the distance of the reflection point and the A widely used method is to draw the relationship with the reflected light intensity on a display screen as a reflected waveform, and search for the point of decrease in backscattering or the peak point due to Fresnel reflection in the reflected waveform as a fault location.
しかしながら、従来の故障点探索方法によると、分岐を
有する光フアイバ線路に適用して、故障点を探索するこ
とができなかった。However, the conventional fault point searching method cannot be applied to an optical fiber line having branches to search for a fault point.
本発明はこのような課題を解決するためになされたもの
で、分岐を有する光フアイバ線路に適用して、故障点を
探索することができる故障点探索方法を得ることを目的
とする。The present invention has been made to solve such problems, and an object of the present invention is to obtain a fault point search method that can be applied to an optical fiber line having branches to search for a fault point.
このような目的を達成するために、
本願の第１発明（請求項１に係る発明）では、分岐を有
する光フアイバ線路での断線点を探索するものとし、以
下の方法で、故障位置（断線位置）および故障区間（断
線区間）を判定する。In order to achieve such an object, the first invention of the present application (the invention according to claim 1) searches for a break point in an optical fiber line having branches, and uses the following method to find the fault location (break point). position) and the fault section (disconnection section).
反射波形の段差点のうち被試験光ファイバ線路に対応す
る標点がない段差点を故障位置と判定する６反射波形の
段差点が１個である場合には、最も測定端に近い標点と
測定端との間を、故障区間と判定する。反射波形の段差
点が複数である場合には、段差点の対応がない標点のう
ち最も測定端に近い標点とこの標点に最も近い測定端側
の分岐点との間を、故障区間と判定する。Among the step points in the reflected waveform, the step point that does not have a gauge corresponding to the optical fiber line under test is determined to be the fault location.6 If there is only one step point in the reflected waveform, select the step point closest to the measurement end. The area between the measurement end and the measurement end is determined to be a failure area. If there are multiple step points in the reflected waveform, the fault interval is defined as the point between the point closest to the measurement end among the points without a corresponding step point and the branch point on the measurement end side closest to this point. It is determined that
また、本願の第２発明（請求項２に係る発明）では、分
岐を有する光フアイバ線路での損失増加点を探索するも
のとし、以下の方法で、故障位置（損失増加位置）およ
び故障区間（損失増加区間）を判定する。In addition, in the second invention of the present application (invention according to claim 2), a loss increase point in an optical fiber line having branches is searched, and the failure position (loss increase position) and failure area ( (loss increase interval) is determined.
反射波形の段差点のうち被試験光ファイバ線路に対応す
る標点がない段差点を故障位置すなわち故障段差点と判
定する。標点との対応があるすべての段差点よりも故障
段差点が測定端側にある場合には、最も測定端に近い標
点と測定端との間を故障区間と判定する。それ以外の場
合のうち、損失増加により反射光強度の低下を生じた段
差点の中で最も遠距離にある段差点が、故障段差点に近
い遠距離側の分岐点よりも遠距離側にある場合には、故
障段差点の前後の分岐点の間を故障区間と判定する。そ
れ以外の場合、損失増加により反射光強度の低下を生じ
た段差点の中で最も遠距離にある段差点に対応するｉｌ
ｌ路端末と故障段差点に最も近い測定端側の分岐点との
間を、故障区間と判定する。Among the step points of the reflected waveform, a step point where there is no reference point corresponding to the optical fiber line under test is determined to be a failure position, that is, a failure step point. If the faulty step point is closer to the measurement end than all the step points that correspond to the gauge point, the area between the gauge point closest to the measurement end and the measurement end is determined to be the failure section. In other cases, the farthest step point among the step points where the reflected light intensity has decreased due to increased loss is located on the far side of the branch point that is closer to the failure step point. In this case, the area between the branch points before and after the failure step point is determined to be the failure section. In other cases, the il corresponding to the farthest step point among the step points where the reflected light intensity has decreased due to increased loss.
The area between the L road terminal and the branch point on the measurement end side closest to the failure step point is determined to be the failure section.
したがってこの発明によれば、
その第１発明では、分岐を有する被試験光ファイバ線路
での断線点を、故障点として探索することができる。Therefore, according to the present invention, in the first aspect, it is possible to search for a break point in an optical fiber line under test having a branch as a failure point.
また、その第２発明では、分岐を有する被試験光ファイ
バ線路での損失増加点を、故障点として探索することが
できる。Further, in the second invention, a point of increased loss in an optical fiber line under test having a branch can be searched as a failure point.
以下、本発明に係る分岐光ファイバ線路の故障点探索方
法を詳細に説明する。Hereinafter, the method for searching for a fault point in a branched optical fiber line according to the present invention will be explained in detail.
実施例の説明に入る前に、本願発明について説明を加え
る。一般に、光ファイバに光パルスを入射すると、後方
散乱光とフレネル反射光が反射するが、フレネル反射光
は反射点における光ファイバの状態により発生しない場
合がある。そこで、本発明では、すべての故障を探索可
能とするため、後方散乱光を利用する。また、本発明の
故障点探索方法は、（１）断線の場合と、（２）局所曲
げや金属腐食に伴う水素などによる光損失増加の場合と
で、異なる。以下、これら二つの場合の故障点探索方法
について説明する。Before going into the description of the embodiments, the present invention will be explained. Generally, when a light pulse is input into an optical fiber, backscattered light and Fresnel reflected light are reflected, but Fresnel reflected light may not be generated depending on the state of the optical fiber at the reflection point. Therefore, in the present invention, backscattered light is used to make it possible to search for all failures. Furthermore, the failure point search method of the present invention differs depending on (1) a case of wire breakage, and (2) a case of increased optical loss due to hydrogen or the like associated with local bending or metal corrosion. Hereinafter, methods for searching for failure points in these two cases will be explained.
先ず、断線点の探索方法について、説明する。First, a method of searching for a disconnection point will be explained.
なお、以下では説明を容易とするために、断線点を１箇
所としている。Note that in the following description, in order to simplify the explanation, there will be one disconnection point.
第２図は、分岐を有する光フアイバ線路を例示し、光パ
ルス試験器の構成と、故障前の反射波形とを合わせて示
している。同図において、１は光パルス試験器であり、
光パルス発生器１）．方向性結合器１２．コネクタ１３
．光・電変換器１４゜処理部１５および表示部１６を備
えている。光パルス発生器１）で発生させた光パルスは
、方向性結合器１２およびコネクタ１３を通して、被試
験光ファイバ線路２に送出される。光フアイバ線路２で
生じた後方散乱やフレネル反射による戻り光は、コネク
タ１３と方向性結合器１２を通して光・電変換器１４で
電気信号に変換され、処理部１５に送られる。処理部１
５では、信号強度を対数変換する他、パルス送信後の遅
延時間に光パルスの伝搬速度を掛けて距離に変換する。FIG. 2 illustrates an optical fiber line having branches, and also shows the configuration of the optical pulse tester and the reflected waveform before failure. In the figure, 1 is an optical pulse tester,
Optical pulse generator 1). Directional coupler 12. Connector 13
．． A photoelectric converter 14 includes a processing section 15 and a display section 16. The optical pulses generated by the optical pulse generator 1) are sent to the optical fiber line 2 under test through the directional coupler 12 and the connector 13. Return light due to backscattering or Fresnel reflection generated in the optical fiber line 2 is converted into an electrical signal by an optical/electrical converter 14 through a connector 13 and a directional coupler 12, and is sent to a processing section 15. Processing part 1
In step 5, in addition to logarithmically converting the signal strength, the delay time after pulse transmission is multiplied by the propagation speed of the optical pulse to convert it into distance.
なお、本発明の故障点探索方法では、フレネル反射によ
るスパイク状の反射波を用いないため、処理部１５にお
いて、スパイク状の反射波を検知して除去するなどの処
理を行う。処理結果は、横軸を距離、縦軸に信号強度（
反射量）を示す反射波形として、表示部１６に表示され
る。Note that the fault point searching method of the present invention does not use spike-shaped reflected waves due to Fresnel reflection, so the processing unit 15 performs processing such as detecting and removing the spike-shaped reflected waves. The processing results show distance on the horizontal axis and signal strength (on the vertical axis).
The reflected waveform is displayed on the display unit 16 as a reflected waveform indicating the amount of reflection.
次に、線路構成に関して説明する。光フアイバ線路２は
、すべて同一特性の光ファイバが接続され、その接続点
の損失は、分岐点の光損失や破断による光損失、故障点
の光損失に比較して無視できるものとする。また、光フ
アイバ線路２の分岐点は、光ファイバ融着形カブラなど
を用いて構成されている。ここで、光フアイバ線路２は
、Ｃ１〜Ｃ？、Ｂ、、Ｂ！の記号を付し、それぞれ線路
区間、分岐点として識別する。なお、第２図に示した一
点鎖線は、線路構成と反射波形との対応位置を示してい
る。Next, the line configuration will be explained. In the optical fiber line 2, optical fibers having the same characteristics are all connected, and the loss at the connection point is negligible compared to the optical loss at the branch point, the optical loss due to breakage, and the optical loss at the failure point. Further, the branch point of the optical fiber line 2 is constructed using an optical fiber fusion type coupler or the like. Here, the optical fiber line 2 is C1 to C? ,B,,B! , and identify them as track sections and branch points. In addition, the dashed-dotted line shown in FIG. 2 shows the corresponding position of a line structure and a reflected waveform.
次に、第２図を用いて、反射波形の特性を説明する０反
射波形の各部を識別するため、水平部分には記号Ｒ８〜
Ｒ７を、段差部分には記号Ｇ、〜Ｇ、を付している。ま
ず、反射波形のＲ１０部分は、線路区間Ｃ，の後方散乱
の反射量を示している。図において、Ｒ１は水平に表さ
れているが、実際には、光ファイバの光損失があるため
、右下がりに傾斜している。但し、この傾斜は、本発明
の故障点探索方法では後述のように段差点のみを問題と
するため、無視した。傾斜を無視している点については
、Ｒ２−Ｒ７についても同様である。Next, using FIG. 2, in order to identify each part of the 0 reflected waveform to explain the characteristics of the reflected waveform, symbols R8 to
R7 and symbols G and ~G are attached to the stepped portions. First, the R10 portion of the reflected waveform indicates the amount of backscattered reflection from the line section C. Although R1 is shown horizontally in the figure, it is actually inclined downward to the right due to optical loss in the optical fiber. However, this slope was ignored because the failure point search method of the present invention deals only with step points as described later. The same applies to R2-R7 in that the slope is ignored.
Ｒ１に続く段差点Ｇ１は、光ファイバの分岐による損失
を表している０例えば、入力ボート２個、出力ポート２
個の光ファイバ融着形カブラを用い入力ボートを１ボー
ト無接続として分岐点を構成した場合、最低３ｄＢの段
差が生じる。Ｒ□は、線路区間Ｃ８およびＣ１の後方散
乱光が加算された反射量を示している０段差点Ｇ８は、
線路区間Ｃ１の端末点であり、この点で線路区間Ｃ３の
後方散乱がなくなることを示している。続ＵＳは、線路
区間Ｃ２のみの後方散乱を示している０分岐点Ｂ２以降
は、分岐数が４分岐であるが、反射波形に段差が生じる
現象は、２分岐の場合と同様である。The step point G1 following R1 represents the loss due to branching of the optical fiber.For example, 2 input ports, 2 output ports
When a branch point is configured using two optical fiber fusion type couplers and one input port is left unconnected, a step difference of at least 3 dB occurs. R□ indicates the amount of reflection obtained by adding the backscattered light from the track sections C8 and C1. The zero step point G8 is:
This is the terminal point of the track section C1, and indicates that backscattering of the track section C3 disappears at this point. In the continuation US, the number of branches is four after the 0-branch point B2, which shows backscattering only in the line section C2, but the phenomenon in which a step occurs in the reflected waveform is the same as in the case of two branches.
ここで、反射波形の段差点の距離と測定端から光フアイ
バ線路２の分岐点あるいは線路端末までの距離は、一致
する。また、線路が断線すると、線路の断線点と同一距
離の反射波形上の位置に、段差が生じる。この特性を用
いて、分岐を有する光フアイバ線路での断線点の探索は
、次の方法を適用して行うことができる。Here, the distance between the step points of the reflected waveform and the distance from the measurement end to the branch point or line end of the optical fiber line 2 match. Furthermore, when a line breaks, a step occurs at a position on the reflected waveform at the same distance as the line break point. Using this characteristic, the following method can be applied to search for a break point in an optical fiber line having branches.
すなわち、「反射波形の段差点のうち光フアイバ線路に
対応する標点がない段差点を故障位置と判定する一方、
反射波形の段差点が１個である場合には、最も測定端に
近い標点と測定端との間を故障区間と判定し、反射波形
の段差点が複数である場合には、段差点の対応がない標
点のうち最も測定端に近い標点とこの標点に最も近い測
定端側の分岐点との間を故障区間と判定する」方法を適
用することにより、光フアイバ線路２での断線点の探索
を行うことができる。なお、上述の方法においては、線
路の分岐点および線路端末を総称して標点と定義し、ま
た反射波形の段差点の距離と標点の測定端からの積算距
離とが一致するとき、これを段差点と標点とが対応する
と定義している。In other words, ``among the step points of the reflected waveform, the step points that do not have a gauge corresponding to the optical fiber line are determined to be the fault location;
If there is one step point in the reflected waveform, the area between the gauge point closest to the measurement end and the measurement end is determined to be the fault zone, and if there are multiple step points in the reflected waveform, the fault section is determined as the fault section. By applying the method of ``determining the fault section between the gauge point closest to the measuring end among the uncorresponding gauge points and the branch point on the measuring end side closest to this gauge point, It is possible to search for disconnection points. In addition, in the above method, the branch point of the track and the end of the track are collectively defined as the gauge point, and when the distance of the stepped point of the reflected waveform and the cumulative distance from the measuring end of the gauge point match, this is defined as the correspondence between the step point and the gauge point.
次に、具体的な断線点の探索例について、第１図（ａ）
〜（Ｃ）を参照しながら説明する。Next, regarding a specific example of searching for a disconnection point, see Figure 1(a).
This will be explained with reference to (C).
先ず、線路区間Ｃ１が断線した場合について、第１図（
ａｌを用いて説明する。同図では、線路区間Ｃ１がＦ点
にて断線した場合に測定される反射波形を、線路構成と
併せて示している。この反射波形に、上述した故障点探
索方法を適用する。まず、反射波形を見ると、段差点が
１個あるが、この段差点Ｇ、に対応する線路の標点がな
いので、故障位置はこの段差点Ｇｆにあることが分かる
。次に、故障区間は、反射波形の段差点が１個であるの
で、最も測定端に近い標点、即ち分岐点Ｂ、と測定端と
の間であることが分かる。First, regarding the case where the track section C1 is disconnected, Figure 1 (
This will be explained using al. In the figure, the reflected waveform measured when the line section C1 is disconnected at point F is shown together with the line configuration. The above-described fault point search method is applied to this reflected waveform. First, when looking at the reflected waveform, there is one step point, but since there is no track marker corresponding to this step point G, it can be seen that the fault location is at this step point Gf. Next, since the fault section has one step point in the reflected waveform, it can be seen that it is between the gauge point closest to the measurement end, that is, the branch point B, and the measurement end.
次に、線路区間Ｃ８が断線した場合について、第１図（
ｂｌを用いて説明する。同図では、線路区間Ｃ！がＦ点
にて断線した場合に測定される反射波形を、線路構成と
併せて示している。この反射波形に、上述した故障点探
索方法を通用する。まず、反射波形の段差点と線路構成
の標点との対応を見ると、線路の標点に対応しない段差
点Ｇ、がある。Next, regarding the case where track section C8 is disconnected, see Figure 1 (
This will be explained using bl. In the same figure, track section C! The reflected waveform measured when the line breaks at point F is shown together with the line configuration. The above-mentioned fault point search method can be applied to this reflected waveform. First, looking at the correspondence between the step points of the reflected waveform and the gauge points of the track configuration, there is a step point G that does not correspond to the gauge point of the track.
そこで、この段差点Ｇｆを故障位置と判定する。Therefore, this step point Gf is determined to be the failure position.
故障区間は、反射波形の段差点が複数であるから、段差
点の対応がない標点のうち最も測定端に近い標点、即ち
分岐点Ｂ２と、この標点に最も近い測定端側の分岐点、
即ち分岐点Ｂ、との間であることが分かる。Since there are multiple step points in the reflected waveform, the failure zone includes the point closest to the measurement end among the points with no corresponding step point, that is, branch point B2, and the branch on the measurement end side closest to this point. point,
That is, it can be seen that it is between branch point B.
次に、線路区間Ｃ７が断線した場合について、第１図（
Ｃ１を用いて説明する。同図では、線路区間Ｃ７がＦ点
にて断線した場合に測定される反射波形を、線路構成と
併せて示している。まず、反射波形の段差点と線路構成
の標点との対応を見ると、線路の標点に対応しない段差
点Ｇｙがある。そこで、この段差点を故障位置と判定す
る。故障区間は、反射波形の段差点が複数であるから、
段差点の対応がない標点のうち最も測定端に近い標点、
即ち線路区間Ｃ’ｒの端末と、この標点に最も近い測定
端側の分岐点、即ち分岐点Ｂ２との間であることが分か
る。Next, regarding the case where track section C7 is disconnected, see Figure 1 (
This will be explained using C1. In the same figure, the reflected waveform measured when the line section C7 is disconnected at point F is shown together with the line configuration. First, looking at the correspondence between the step points of the reflected waveform and the gauge points of the track configuration, there is a step point Gy that does not correspond to the gauge point of the track. Therefore, this step point is determined to be the failure position. Since the fault section has multiple step points in the reflected waveform,
The gauge closest to the measurement end among the gauges that do not have a corresponding step point,
That is, it can be seen that it is between the terminal of the track section C'r and the branch point on the measuring end side closest to this gauge point, that is, the branch point B2.
次に、損失増加点の探索方法について、説明する。なお
、以下では説明を容易とするために、損失増加点は１箇
所としている。Next, a method of searching for a loss increase point will be explained. Note that in the following description, in order to simplify the explanation, the number of loss increasing points is assumed to be one.
分岐光ファイバ線路のある点で損失増加が生じた場合の
特性として、故障点において反射波形に小さい段差が生
じると、故障点のある線路の後方では反射量が故障点で
生じた段差骨だけ一様に低下する。この特性を用いて、
分岐を有する光フアイバ線路での損失増加点の探索は、
次の方法を適用して行うことができる。When loss increases at a certain point on a branched optical fiber line, if there is a small step in the reflected waveform at the fault point, the amount of reflection at the back of the line where the fault is located is equal to only the step bone that occurred at the fault point. It decreases like that. Using this characteristic,
The search for the point of increased loss in an optical fiber line with branches is as follows:
This can be done by applying the following method.
すなわち、［反射波形の段差点のうち線路に対応する標
点がない段差点を故障位置すなわち故障段差点と判定す
る一方、標点との対応があるすべての段差点よりも故障
段差点が測定端側にある場合には、最も測定端に近°い
標点と測定端との間を故障区間と判定し、それ以外の場
合のうち、損失増加により反射光強度の低下を生じた段
差点の中で最も遠距離にある段差点が、故障段差点に近
い遠距離側の分岐点よりも遠距離側にある場合には、故
障段差点の前後の分岐点の間を故障区間と判定し、それ
以外の場合、損失増加により反射光強度の低下を生じた
段差点の中で最も遠距離にある段差点に対応する線路端
末と故障段差点に最も近い測定端側の分岐点との間を故
障区間と判定する」方法を適用することにより、光フア
イバ線路２での損失増加点の探索を行うことができる。In other words, [among the step points of the reflected waveform, a step point that does not have a gauge corresponding to the track is determined to be a fault location, that is, a fault step point, while a fault step point is measured more than all step points that have correspondence with a gauge. If it is on the edge side, the area between the gauge point closest to the measurement edge and the measurement edge is determined to be the fault area, and in other cases, it is the step point where the reflected light intensity has decreased due to increased loss. If the farthest step point is located on the far side than the farthest branch point near the fault step point, the area between the branch points before and after the fault step point is determined to be the fault section. , in other cases, between the line terminal corresponding to the step point that is the farthest among the step points where the reflected light intensity has decreased due to increased loss, and the branch point on the measurement end side closest to the faulty step point. By applying the method of ``determining ``to be a failure section,'' it is possible to search for a point of increased loss in the optical fiber line 2.
次に、具体的な損失増加点の探索例について、第１図（
ｄ）〜ｉｆ）を参照しながら説明する。Next, we will discuss a specific example of searching for a loss increase point in Figure 1 (
This will be explained with reference to d) to if).
先ず、線路区間Ｃ１に損失増加が生じた場合について、
第１図（ｄ）を用いて説明する。同図では、線路区間Ｃ
１のＦ点を損失増加点とした場合に測定される反射波形
すなわち故障後の反射波形を実線にて、故障前の反射波
形を破線にて、線路構成と併せて示している。この反射
波形に、上述した故障点探索方法を適用する。まず、故
障後の反射波形から、故障位置は、標点との対応がない
段差点Ｇ、であることが分かる。故障区間は、故障段差
点Ｇｆが標点との対応があるすべての段差点より測定端
側にあるので、最も測定端に近い標点、即ち分岐点Ｂ＋
と測定端との間であることが分かる。First, regarding the case where loss increases in line section C1,
This will be explained using FIG. 1(d). In the same figure, track section C
The reflected waveform measured when point F of No. 1 is set as the loss increase point, that is, the reflected waveform after failure, is shown as a solid line, and the reflected waveform before failure is shown as a broken line, together with the line configuration. The above-described fault point search method is applied to this reflected waveform. First, it can be seen from the reflected waveform after the failure that the failure position is a step point G that does not correspond to the gauge point. In the fault section, since the fault step point Gf is located closer to the measurement end than all the step points that correspond to gauge points, the fault step point Gf is located at the gauge point closest to the measurement end, that is, the branch point B+.
and the measurement end.
次に、線路区間Ｃｔに損失増加が生じた場合について、
第１図（ｅ）を用いて説明する。同図では、線路区間Ｃ
２のＦ点を損失増加点とした場合に測定される反射波形
すなわち故障後の反射波形を実線にて、故障前の反射波
形を破線にて、線路構成と併せて示している。この反射
波形に、上述した故障点探索方法を適用する。まず、故
障後の反射波形から、故障位置は、標点との対応がない
段差点Ｇｒであることが分かる。故障区間は、故障段差
点Ｇ、が標点と対応する段差点の間にあるため、故障後
に反射量の低下を生じた段差点を見ると、反射量の低下
を生じた段差点のうち最も遠距離にある段差点Ｇ？が、
故障段差点Ｇｆに近い遠距離側の分岐点Ｂ！よりもさら
に遠距離側にあるため、故障段差点Ｇ、を挟む分岐点の
間、即ち分岐点Ｂ。Next, regarding the case where an increase in loss occurs in the line section Ct,
This will be explained using FIG. 1(e). In the same figure, track section C
The reflected waveform measured when point F of No. 2 is set as the loss increase point, that is, the reflected waveform after failure, is shown as a solid line, and the reflected waveform before failure is shown as a broken line, together with the line configuration. The above-described fault point search method is applied to this reflected waveform. First, it can be seen from the reflected waveform after the failure that the failure position is a step point Gr that has no correspondence with the gauge point. In the failure section, the failure step point G is between the gauge point and the corresponding step point, so looking at the step points where the amount of reflection has decreased after the failure, it is found that the step point where the amount of reflection has decreased is the lowest among the step points where the amount of reflection has decreased. Step point G in the distance? but,
Branch point B on the far side near the failure step point Gf! Since it is further away than the branch point B, it is between the branch points that sandwich the failure step point G, that is, the branch point B.
と分岐点Ｂ２との間であることが分かる。It can be seen that it is between the point B2 and the branch point B2.
次に、線路区間Ｃ７に損失増加が生じた場合について、
第１図（ｆ）を用いて説明する。同図では、線路区間Ｃ
１のＦ点を損失増加点とした場合に測定される反射波形
すなわち故障後の反射波形を実線にて、故障前の反射波
形を破線にて、線路構成と併せて示している。この反射
波形に、上述した故障点探索方法を適用する。まず、故
障後の反射波形から、故障位置は、標点との対応がない
段差点Ｇ、であることが分かる。故障区間は、故障段差
点Ｇｆが標点との対応があるすべての段差点より測定端
側になく、かつ、故障後に反射量の低下を生じた段差点
のうち、最も遠距離にある段差点が、故障段差点Ｇｆに
近い遠距離側の分岐点よりも遠距離にないため、故障後
に反射量の低下を生じた段差点のうち、最も遠距離にあ
る段差点に対応する線路端末と、即ち線路区間Ｃ９の線
路端末と、故障段差点Ｇｆに最も近い測定端側の分岐点
、即ち分岐点Ｂ２との間にあることが分かる。Next, regarding the case where loss increases in line section C7,
This will be explained using FIG. 1(f). In the same figure, track section C
The reflected waveform measured when point F of No. 1 is set as the loss increase point, that is, the reflected waveform after failure, is shown as a solid line, and the reflected waveform before failure is shown as a broken line, together with the line configuration. The above-described fault point search method is applied to this reflected waveform. First, it can be seen from the reflected waveform after the failure that the failure position is a step point G that does not correspond to the gauge point. The fault zone is the step point where the fault step point Gf is not closer to the measurement end than all the step points that correspond to the gauge, and which is the farthest step point among the step points where the reflection amount has decreased after the failure. is not further away than the branch point on the far side near the failure step point Gf, so the line terminal corresponding to the step point that is the farthest among the step points where the amount of reflection has decreased after the failure, That is, it can be seen that it is between the line terminal of the line section C9 and the branch point on the measurement end side closest to the failure step point Gf, that is, the branch point B2.
以上説明したようにこの発明による分岐光ファイバ線路
の故障点探索方法によると、その第１発明では、分岐を
有する被試験光ファイバ線路での断線点を故障点として
探索することができ、またその第２発明では、分岐を有
する被試験光ファイバ線路での損失増加点を故障点とし
て探索することができるようになる。As explained above, according to the method for searching for a fault point in a branched optical fiber line according to the present invention, in the first invention, it is possible to search for a break point in an optical fiber line under test having a branch as a fault point, and In the second invention, it becomes possible to search for a point of increased loss in an optical fiber line under test having a branch as a failure point.
すなわち、光フアイバ線路の建設時の線路長、分岐位置
、分岐数などの線路構成データを利用して、反射波形を
分析することにより、分岐光ファイバ線路での故障点を
探索することが可能となる。In other words, it is possible to search for failure points in branched optical fiber lines by analyzing the reflected waveforms using line configuration data such as line length, branch position, and number of branches at the time of construction of the optical fiber line. Become.
また、分岐光ファイバ線路の故障点探索を、線路端末す
なわち局舎内から行うことが可能であり、効率的な保守
が実現できる利点がある。Further, it is possible to search for a fault point in a branched optical fiber line from the line terminal, that is, from within the station building, and there is an advantage that efficient maintenance can be realized.
また、加入者光フアイバ線路の経済的な構成方法として
、局舎からある点までを１本の光ファイバを布設し、そ
こから光結合器を用いてｎ本に分岐して加入者に接続す
る方法が考えられているが、この場合の故障点探索を容
易に行うことが可能となる利点がある。In addition, as an economical method for configuring subscriber optical fiber lines, one optical fiber is laid from the central office to a certain point, and from there it is branched into n fibers using an optical coupler and connected to the subscriber. This method has the advantage of making it possible to easily search for failure points.
第１図（ａ）〜（Ｃ）は断線点の探索例の説明に用いる
反射波形と線路構成の概要を示す図、第１図（ｄ）〜（
ｆ）は損失増加点の探索例の説明に用いる反射波形と線
路構成の概要を示す図、第２図は本発明に係る分岐光フ
ァイバ線路の故障点探索方法を適用する線路構成を例示
し光パルス試験器の構成と故障前の反射波形とを合わせ
て示した図である。
１・・・光ハルスに験Ｒ１）１・・・光パルス発生器、
１２・・・方向性結合器、１３・・・コネクタ、１４・
・・光・電変換器、１５・・・処理部、１６・・・表示
部、２・・・被試験光ファイバ、Ｃ４〜Ｃ６・・・線路
区間、Ｂ＋、Ｂｔ・・分岐点、Ｇ１ ・・・故障段差点
、Ｇ ｌ−Ｇ ’ｒ・段差点。Figures 1(a) to (C) are diagrams showing an overview of the reflected waveform and line configuration used to explain an example of searching for a disconnection point, and Figures 1(d) to (
f) is a diagram showing an overview of the reflected waveform and line configuration used to explain an example of searching for a loss increase point, and FIG. FIG. 2 is a diagram showing the configuration of a pulse tester and a reflected waveform before a failure. 1...Experiment with optical Halus R1) 1...Optical pulse generator,
12... Directional coupler, 13... Connector, 14...
...Optical/electrical converter, 15... Processing section, 16... Display section, 2... Optical fiber under test, C4 to C6... Line section, B+, Bt... Branch point, G1.・Failure step point, G l-G 'r・step point.
Claims (2)
入射し、その後方散乱による反射光を光・電変換し、さ
らに信号処理を施し、反射点の距離と反射光強度との関
係を反射波形として測定し、前記線路での断線点を探索
する分岐光ファイバ線路の故障点探索方法であって、 前記線路の分岐点および線路端末を総称して標点と定義
し、また前記反射波形の段差点の距離と前記標点の測定
端からの積算距離とが一致するとき、これを段差点と標
点とが対応すると定義したうえ、 前記反射波形の段差点のうち前記線路に対応する標点が
ない段差点を故障位置と判定する一方、前記反射波形の
段差点が１個である場合には、最も測定端に近い標点と
測定端との間を故障区間と判定し、 前記反射波形の段差点が複数である場合には、段差点の
対応がない標点のうち最も測定端に近い標点とこの標点
に最も近い測定端側の分岐点との間を、故障区間と判定
する ようにしたことを特徴とする分岐光ファイバ線路の故障
点探索方法。(1) Inject a light pulse into the optical fiber line under test that has branches, convert the reflected light from backscatter into electricity and then perform signal processing to reflect the relationship between the distance of the reflection point and the intensity of the reflected light. A fault point search method for a branched optical fiber line that measures the waveform and searches for a break point on the line, wherein the branch point and line end of the line are collectively defined as a gauge point, and the reflected waveform is When the distance of the step point and the cumulative distance from the measurement end of the gauge point match, this is defined as the step point and the gauge point corresponding, and the step point of the reflected waveform that corresponds to the track is A step point where there is no point is determined to be a fault position, while if there is one step point in the reflected waveform, a point between the gauge point closest to the measurement end and the measurement end is determined to be a fault section, and the reflection waveform is determined to be a fault location. If there are multiple step points in the waveform, the fault interval is defined as the point between the point closest to the measurement end among the points without corresponding step points and the branch point on the measurement end side closest to this point. A method for searching for a fault point in a branched optical fiber line, characterized in that the fault point is determined.
入射し、その後方散乱による反射光を光・電変換し、さ
らに信号処理を施し、反射点の距離と反射光強度との関
係を反射波形として測定し、前記線路での損失増加点を
探索する分岐光ファイバ線路の故障点探索方法であって
、 前記線路の分岐点および線路端末を総称して標点と定義
し、また前記反射波形の段差点の距離と前記標点の測定
端からの積算距離とが一致するとき、これを段差点と標
点とが対応すると定義したうえ、 前記反射波形の段差点のうち前記線路に対応する標点が
ない段差点を故障位置すなわち故障段差点と判定する一
方、 標点との対応があるすべての段差点よりも前記故障段差
点が測定端側にある場合には、最も測定端に近い標点と
測定端との間を故障区間と判定し、それ以外の場合のう
ち、損失増加により反射光強度の低下を生じた段差点の
中で最も遠距離にある段差点が、前記故障段差点に近い
遠距離側の分岐点よりも遠距離側にある場合には、前記
故障段差点の前後の分岐点の間を故障区間と判定し、そ
れ以外の場合、損失増加により反射光強度の低下を生じ
た段差点の中で最も遠距離にある段差点に対応する線路
端末と前記故障段差点に最も近い測定端側の分岐点との
間を、故障区間と判定する ようにしたことを特徴とする分岐光ファイバ線路の故障
点探索方法。(2) Inject a light pulse into the optical fiber line under test that has a branch, convert the reflected light due to back scattering from optical to electrical, and then perform signal processing to reflect the relationship between the distance of the reflection point and the intensity of the reflected light. A fault point search method for a branched optical fiber line that measures a waveform and searches for a loss increase point in the line, wherein the branch point and the line end of the line are collectively defined as a gauge point, and the reflected waveform When the distance of the step point of the reflected waveform and the cumulative distance from the measurement end of the gauge point match, this is defined as the step point and the gauge point corresponding, and the step point of the reflected waveform that corresponds to the track is defined as corresponding. A step point without a gauge is determined to be a fault position, that is, a fault step point, and if the fault step point is closer to the measurement end than all the step points that correspond to a gauge, then the step closest to the measurement end is determined as the fault point. The area between the gage and the measurement end is determined to be the fault zone, and in other cases, the farthest step point among the step points where the reflected light intensity has decreased due to increased loss is determined to be the fault zone. If the branch point is on the far side than the branch point on the far side close to the point, the area between the branch points before and after the failure step point is determined to be the failure section, and in other cases, the reflected light intensity is reduced due to increased loss. The fault section is determined to be between the line end corresponding to the farthest step point among the step points where the drop has occurred and the branch point on the measuring end side closest to the fault step point. A method for finding failure points in branched optical fiber lines.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2164051A JP2883948B2 (en) | 1990-06-25 | 1990-06-25 | Fault locating method for branch optical fiber line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2164051A JP2883948B2 (en) | 1990-06-25 | 1990-06-25 | Fault locating method for branch optical fiber line |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0454428A true JPH0454428A (en) | 1992-02-21 |
| JP2883948B2 JP2883948B2 (en) | 1999-04-19 |
Family
ID=15785864
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2164051A Expired - Lifetime JP2883948B2 (en) | 1990-06-25 | 1990-06-25 | Fault locating method for branch optical fiber line |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2883948B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110779681A (en) * | 2018-07-26 | 2020-02-11 | 发那科株式会社 | Distance measuring device for detecting abnormality of optical system |
-
1990
- 1990-06-25 JP JP2164051A patent/JP2883948B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110779681A (en) * | 2018-07-26 | 2020-02-11 | 发那科株式会社 | Distance measuring device for detecting abnormality of optical system |
| US11525917B2 (en) | 2018-07-26 | 2022-12-13 | Fanuc Corporation | Distance measuring apparatus which detects optical system abnormality |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2883948B2 (en) | 1999-04-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3527844B2 (en) | Multi-branch optical line test method and apparatus | |
| US6185020B1 (en) | Apparatus for detecting a fault location in an optical fiber line | |
| US5187362A (en) | Loss detection in a branched optical fiber | |
| US6310702B1 (en) | Testing device for multistage multi-branch optical network | |
| JPH0658840A (en) | System and method for inspecting optical fiber | |
| US7469101B1 (en) | Optoelectronic marker for determining ownership of fiber optic cable | |
| CN104655591B (en) | A kind of optical cable generaI investigation device and method of detection beating position | |
| CN105591693A (en) | Integrated test system and integrated test method for fiber-optic network | |
| US11169051B2 (en) | Optical testing devices and related methods | |
| JPH03150442A (en) | Optical fault point locating device | |
| JP2001021445A (en) | Multiple branching optical path test apparatus | |
| JP2002139403A (en) | Testing method of branched optical line | |
| JPH0454428A (en) | Fault point searching method for branched optical fiber line | |
| JP2011069721A (en) | Splitter module, detection method for remaining optical connector using the same, detection method of number of output ports, and optical transmission loss measuring system | |
| JP4160939B2 (en) | Optical line fault search method | |
| JP3762186B2 (en) | Optical transmission line and optical transmission line with optical line monitoring device | |
| US10969302B1 (en) | Optical time-domain reflectometers and related methods | |
| JPH09247102A (en) | Method for monitoring optical line | |
| JPH10153524A (en) | Method and apparatus for testing connection of optical fiber cables | |
| JP3465733B2 (en) | Optical pulse test method | |
| US20210255058A1 (en) | Devices and methods of testing optical systems | |
| US20210255401A1 (en) | Devices and methods of testing optical systems | |
| JP3949266B2 (en) | Multi-branch optical line test method and apparatus | |
| JPS60253836A (en) | Optical fiber analyzer | |
| JP3295595B2 (en) | Optical fiber type physical quantity measurement system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090212 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090212 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100212 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110212 Year of fee payment: 12 |
|
| EXPY | Cancellation because of completion of term | ||
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110212 Year of fee payment: 12 |