JPH08166324A - Light meter - Google Patents

Abstract

(57) [Abstract] [Purpose] When measuring the amount of light output from an optical transmission device, quickly determine the cause of a failure that occurs during system operation, and make a call between two points when measuring the optical line insertion loss. Provided is a light quantity measuring device made possible. An optical signal sent from an optical transmission device is supplied to an optical intensity detecting means and an optical signal detecting means, and the intensity of the optical signal is measured / measured.
Along with the display, it is determined whether or not the transmission frame sent by the optical transmission device is the one defined on the transmission path.
The display is done. Similarly, a transmission frame is output to the optical transmission device, and it is determined whether or not the optical transmission device normally operates for reception thereof. When the light quantity measuring devices are connected to each other, the voice input / output unit, voice encoding / decoding unit, and digital voice multiplexing / demultiplexing unit use the information channel of the transmission frame to secure a bidirectional communication path. .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light quantity measuring instrument used for installation and maintenance of an optical transmission line for transmitting an optical signal by a two-core bidirectional digital transmission system using an optical fiber as a medium.

[0002]

2. Description of the Related Art When laying and maintaining an optical fiber,
The intensity measurement of an optical signal transmitted from an optical transmission device (hereinafter, measurement of output light amount of optical transmission device) and the measurement of transmission loss of an optical fiber serving as a transmission medium (hereinafter, optical line insertion loss measurement) are generally performed.

FIG. 4 is a diagram showing a system configuration for measuring the output light quantity of an optical transmission device using a conventional light quantity measuring device.
Is a light amount measuring device, 2 is an optical transmission device, 10 is a light emitting unit, 11 is a light receiving unit, 12 is a light intensity detecting unit, 13 is a light intensity display unit, 2
Reference numeral 0 is an output unit of the optical transmission device 2, 21 is an input unit of the optical transmission device 2, and 50a is a reference optical code. Reference light code 50a
Is a short optical cord having optical connectors at both ends, and is connected between the optical transmission device 2 and the light quantity measuring device 1.

In such a configuration, the optical signal sent from the output section 20 of the optical transmission device 2 is the reference optical code 50a.
It is incident on the light receiving unit 11 of the light quantity measuring device 1 via the light intensity measuring unit 1, and the light intensity detecting unit 12 performs processing such as current / voltage conversion, A / D conversion, wavelength correction, and dBm conversion of measured values. Then, the absolute value of the light intensity obtained by this (dB
m) is visually displayed on the light intensity display unit 13 as a measurement value.

Next, the conventional optical line insertion loss measurement will be described. Here, the optical line insertion loss is a combination of the transmission loss of the optical fiber serving as the transmission medium and the insertion loss of the optical connector which is influenced by the state of the end faces of the optical connectors at both ends. FIG. 5 is a diagram showing a configuration of a system for performing this optical line insertion loss measurement. 1a and 1b are the above-mentioned conventional light quantity measuring devices, and 51a and 51b are the measured light of the installed two-core optical transmission line. Fiber. The measured optical fibers 51a and 51b transmit optical signals in different directions. The conventional method of measuring optical line insertion loss is shown below.

(1) First, the reference optical code 5 shown in FIG.
0a is connected between the light emitting unit 10 of the light amount measuring device 1a and the light receiving unit 11 of the light amount measuring device 1b, and the absolute value of the optical output transmitted by the light amount measuring device 1a is measured on the light amount measuring device 1b side. At this time, the light quantity measuring device 1b holds the obtained measured value as a reference value (0db). (2) Similarly, the absolute value of the optical output transmitted by the light amount measuring device 1b is measured on the light amount measuring device 1a side via the reference optical code 50a and held as the reference value. (3) Next, to the both ends of the section to be measured (optical fibers 51a and 51b to be measured) of the two-core optical transmission line, the light quantity measuring devices 1a and 1a are provided.
Each of b is carried, and the light quantity measuring devices 1a and 1b are connected to both ends as shown in FIG. Also, at this time, a wired or wireless meeting means is secured for communication of work between two points. (4) After the measured optical fibers 51a and 51b are connected, an optical signal is sent from each light emitting unit 10. The optical signal sent from the light quantity measuring device 1a is the optical fiber 51a to be measured.
After being attenuated at, it is incident on the light quantity measuring device 1b, and the measured value of the light intensity is displayed as a relative value with respect to the reference value held in (1), that is, this relative value is inserted into the optical fiber 51a to be measured. It will be a loss. Similarly,
The optical line insertion loss of the measured optical fiber 51b is displayed on the light quantity measuring device 1a, and the confirmation of both measurement values and the completion of the work are notified through the meeting means secured in (3).

[0007]

In the conventional technique described above, the measurement information obtained when measuring the output light quantity of the optical transmission device is only the intensity of the optical signal transmitted and received by the optical transmission device.
For example, if a failure such as a bit error occurred during system operation, it was not possible to determine whether the cause of the failure was in the optical fiber, which is the transmission medium, or in the optical transmission device that transmits and receives optical signals. .

Further, in the case of measuring the optical line insertion loss between two points, it is necessary to secure a meeting means for notifying the start and end of the work and notifying both measurement values.
Generally, a telephone is connected to a wire such as a telephone line, or a portable wireless device or the like is applied, but it takes a considerable amount of time to secure these, and either application may be difficult. Further, in each case, the worker has to carry a tool for securing the meeting means, which has a drawback that the workability is extremely poor.

According to the present invention, when a failure such as a bit error occurs during system operation, it is promptly determined whether the cause is the optical fiber as the transmission medium or the optical transmission device side for transmitting and receiving an optical signal. The first purpose is to enable judgment.

A second object is to improve workability by eliminating the need for a meeting means for measuring the optical line insertion loss between two points.

[0011]

According to the first aspect of the present invention,
In order to achieve the first object, in addition to a means for detecting and displaying the intensity of an incident optical signal in a light receiving section, an optical signal detecting means for extracting pulse information from an input optical signal and its pulse information A frame synchronization establishing means for extracting a predetermined transmission frame from the frame and detecting a match between the extracted transmission frame and a transmission frame predetermined on the transmission path, and a synchronization display means for displaying that the frame synchronization has been established according to the detection result. And a transmission frame generating means for generating a transmission frame predetermined on the transmission path.

In order to achieve the second object of the invention, in addition to the above configuration, a voice input / output means for inputting / outputting voice and an encoding / decoding of the voice are provided. Voice code / decoding means for performing, digital voice multiplexing means for synthesizing the coded voice information on a predetermined information channel of the transmission frame of the transmission frame generating means, and a predetermined information channel from the extracted transmission frame And a digital voice separating means for separating the voice information.

[0013]

According to the present invention, the optical signal transmitted by the optical transmission device is supplied to the optical intensity detection means and the optical signal detection means, and the intensity of the optical signal transmitted by the optical transmission device is measured and displayed. At the same time, it is determined and displayed whether or not the transmission frame transmitted by the optical transmission device is the one defined on the transmission path. At the same time, since an optical signal of a transmission frame defined on the transmission path is output to the optical transmission device, it is determined whether the optical transmission device operates normally when the optical transmission device receives the optical signal. You can also That is, it is possible to simultaneously measure the intensity of the optical signal transmitted by the optical transmission device and confirm the transmission / reception of the bidirectional transmission frame.

When two light quantity measuring devices according to the second aspect of the present invention are arranged opposite to each other and are connected to both ends of a two-core optical transmission line, each light quantity measuring device transmits and receives a transmission frame of an optical signal at the same time. , The intensity of each optical signal received is detected and displayed. Further, the voice input / output means, the voice encoding / decoding means, the digital voice multiplexing means and the digital voice separating means use the information channel of the transmission frame defined on the transmission path to perform bidirectional operation between the two light quantity measuring devices. Secure a communication path. Therefore, if the optical line insertion loss measurement is performed using the above-mentioned light quantity measuring device, a call can be made without newly securing a meeting means between the two points, and at the same time, the optical line of the prior art described with reference to FIG. The two-way bidirectional optical line insertion loss can be measured by the same procedure as the insertion loss measuring method.

[0015]

An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a diagram showing a configuration of a system for measuring an output light amount of an optical transmission device and confirming transmission / reception of bidirectional transmission frames according to the present embodiment. 3 is a light amount measuring device according to the present invention, 30 is a light emitting unit, 31 Is a light receiving unit, 32 is a light intensity detection unit, 33 is a light intensity display unit, 34 is an optical signal detection unit, 35 is a frame synchronization establishment unit, 36 is a synchronization display unit, and 37 is Bch.
A multiplexing unit, 38 is a transmission frame generating unit, 39 is a Bch separating unit, 40 is a voice coding / decoding unit, and 41 is a voice input / output unit. Reference numerals 50a and 50b are reference optical codes of the same standard, and two optical cables are simultaneously used to transmit optical signals in different directions.

FIG. 3 is a diagram showing the structure of a transmission frame of an optical transmission line according to the present invention, where F is a frame bit and B1ch to Bnch are n information channels.
The frame bit F is composed of a header part H used for establishing synchronization and a frame number part FNo for identifying each frame of the multi-frame structure.

The operation of measuring the output light quantity of the optical transmission device and confirming the transmission / reception of the bidirectional transmission frame will be described below with reference to FIGS. 1 and 3. In measuring the output light quantity of the optical transmission device, as in the conventional technique described above with reference to FIG.
The absolute value of the optical output transmitted by the optical transmission device 2 obtained using the reference optical code 50a is used as the measurement value. The optical signal sent from the optical transmission device 2 is incident on the light receiving section 31 of the light quantity measuring device 3 via the reference optical code 50a, and the incident optical signal is converted into current / voltage by the light intensity detection section 32 and A / D conversion is performed. After processing such as conversion, wavelength correction, and dBm conversion of the measured value, the light intensity display section 33 visually displays.

At the same time, the optical signal incident on the light receiving section 31 is subjected to processing such as pulse extraction, amplitude amplification, and waveform shaping in the optical signal detection section 34. Here, a high-speed and high slew-rate operational amplifier, a fast response comparator, or the like may be used for pulse extraction. next,
The extracted pulse train is bit-synchronized by the frame synchronization establishing unit 35 based on the header portion H (see FIG. 3) of the frame bit F, and the received transmission frame is transmitted on the transmission path from the information of the frame number portion FNo. It is determined whether or not it is the one defined in step 1. If they match, frame synchronization is established. The synchronization display unit 36 visually displays whether or not bit synchronization and frame synchronization are established based on the information of the frame synchronization establishment unit 35.

On the other hand, the light emitting section 30 is the transmission frame generating section 3
The transmission frame defined by 8 is transmitted on the transmission path, and its optical signal is incident on the optical transmission device 2 via the reference optical code 50b. If the optical transmission device 2 is previously provided with a means for visually displaying the frame synchronization state like the light quantity measuring device 3, is the optical transmission device 2 normally receiving the transmission frame determined on the transmission path? Visually indicate whether or not.

Therefore, if this light quantity measuring device is used,
Whether the optical transmission device output light quantity of the optical signal transmitted by the optical transmission device 2 connected through the reference optical cord 50a is measured, and at the same time, the transmission frame transmitted by the optical transmission device 2 is determined on the transmission path. You can check whether or not
Further, by inputting the optical signal of the transmission frame defined on the transmission path to the optical transmission device 2 using the reference optical code 50b, it is determined whether the optical transmission device 2 can normally receive the prescribed transmission frame. A decision can be made.

Next, a method of measuring the optical line insertion loss according to this embodiment will be described with reference to FIGS. FIG. 2 is a block diagram showing the configuration of a system for measuring the optical line insertion loss. 3a and 3b are the above-mentioned light quantity measuring devices according to the present invention, and 51a and 51b are the covered two-core optical transmission lines. There is a measuring optical fiber.

As described above, the light quantity measuring devices 3a and 3
Since b is provided with a means for transmitting the optical signal of the transmission frame defined on the transmission path and a means for synchronizing the transmission frame to be respectively received, the two optical fibers are opposed to each other via the two-fiber optical fibers 51a and 51b. A two-core bidirectional optical transmission line can be established by connecting to the optical fiber.

The audio input / output unit 41 provided in the light quantity measuring devices 3a and 3b has a function equivalent to a microphone and a speaker such as a headset, and the audio information input by this is audio. The data is encoded by the encoding / decoding unit 40, and multiplexed by the Bch multiplexing unit 37 on the information channel Bnch designated on the transmission format. In addition, the audio information on the side of the opposite light quantity measuring device is Bch.
The separation unit 39 selects and extracts the Bnch on the transmission format, is decoded by the audio encoding / decoding unit 40, and is reproduced by the audio input / output unit 41.

With the above-mentioned structure, the two light quantity measuring devices of the present invention are arranged in opposition to each other and are connected via the two-core optical fiber to detect the intensity of each optical signal received. At the same time, the two-way optical transmission path is established and the communication between the two points can be performed.

Therefore, when the optical line insertion loss measurement is performed by using the two optical quantity measuring devices of this embodiment, the two points required in the conventional optical line insertion loss measurement described above with reference to FIG. There is no need to newly secure a meeting means for communicating work between them.

In the above description, the information channel used to secure the communication path is limited to Bnch, but the information channel to be selected is provided by providing the Bch separation unit 39 with a switch for selecting the channel. B1
It goes without saying that ch to Bnch can be arbitrarily selected.

[0027]

As described above, the light quantity measuring instrument according to the first aspect of the present invention detects and displays the intensity of the optical signal transmitted by the optical transmission device, and at the same time transmits the transmission frame transmitted by the optical transmission device. It is not possible with the prior art because it is possible to determine whether or not it is the one specified on the road and whether or not the optical transmission device can normally receive the specified transmission frame. It is possible to quickly determine whether the cause of failure such as a bit error is in the optical fiber that is the transmission medium or in the optical transmission device side that transmits and receives the optical signal.

When two light quantity measuring devices according to the second aspect of the present invention are arranged opposite to each other and are connected via a two-core optical fiber, the intensity of each optical signal received is detected and displayed, and at the same time, the bidirectional It establishes the optical transmission line of the above and operates so that a call can be made between two points. Therefore, when measuring the optical line insertion loss between two points, it is not necessary to newly secure a meeting means for notifying the start and end of the work and notifying the measured values of both, and the workability is greatly improved. To be done.

[Brief description of drawings]

FIG. 1 is a block diagram showing a system configuration for measuring an output light amount of an optical transmission device and bidirectional transmission frame transmission / reception confirmation using a light amount measuring device of the present invention.

FIG. 2 is a block diagram showing a system configuration of optical line insertion loss measurement using the light quantity measuring device of the present invention.

FIG. 3 is a configuration diagram of a transmission format of an optical transmission line used in the light quantity measuring device of the present invention.

FIG. 4 is a block diagram showing a system configuration for measuring an output light amount of an optical transmission device using a conventional light amount measuring device.

FIG. 5 is a block diagram showing a system configuration of an optical line insertion loss measurement using a conventional light quantity measuring device.

[Explanation of symbols]

 2 optical transmission device 3, 3a, 3b light quantity measuring device 20 output part of optical transmission device 21 input part of optical transmission device 30 light emitting part 31 light receiving part 32 light intensity detection part 33 light intensity display part 34 optical signal detection part 35 frame synchronization Establishing unit 36 Synchronous display unit 37 Bch multiplexing unit 38 Transmission frame generating unit 39 Bch demultiplexing unit 40 Voice coding / decoding unit 41 Voice input / output unit 50a, 50b Reference optical code 51a, 51b Laminated optical fiber under measurement

Claims (2)

[Claims] 1. A light quantity measuring device for measuring the intensity of an optical signal transmitted from an optical transmission device of a transmission system having a two-core bidirectional optical transmission line, wherein the intensity of an optical signal incident on a light receiving section is detected. Light intensity detection means, a light intensity display means for displaying the detection result, an optical signal detection means for extracting pulse information from the input optical signal, and a predetermined transmission frame extracted from the pulse information for extraction. A frame synchronization establishment means for detecting a match between the transmission frame and a transmission frame previously determined on the transmission path, and a synchronization display means for indicating that the frame synchronization has been established according to the detection result. An optical quantity measuring instrument comprising a transmission frame generating means for generating a transmission frame defined on the road. 2. The light quantity measuring device according to claim 1, wherein a voice input / output unit for inputting / outputting voice, a voice encoding / decoding unit for encoding and decoding the voice, and encoded voice It comprises digital voice multiplexing means for synthesizing information on a predetermined information channel of the transmission frame of the transmission frame generating means, and digital voice separating means for separating the voice information of the predetermined information channel of the extracted transmission frame. A light quantity measuring device characterized in that