ANRITSU MW9087 Operation Manual

MW9087 Series

Card OTDR

Operation Manual

12th Edition

For safety and warning information, please read this manual before attempting to use the equipment. Keep this manual with the equipment.

ANRITSU CORPORATION

Document No.: M-W3543AE-12.0

Safety Symbols

To prevent the risk of personal injury or loss related to equipment malfunction, Anritsu Corporation uses the following safety symbols to indicate safety-related information. Ensure that you clearly understand the meanings of the symbols BEFORE using the equipment. Some or all of the following symbols may be used on all Anritsu equipment. In addition, there may be other labels attached to products that are not shown in the diagrams in this manual.

Symbols used in manual

DANGER

WARNING

CAUTION

This indicates a very dangerous procedure that could result in serious injury or death if not performed properly.

This indicates a hazardous procedure that could result in serious injury or death if not performed properly.

This indicates a hazardous procedure or danger that could result in light-to-severe injury, or loss related to equipment malfunction, if proper precautions are not taken.

Safety Symbols Used on Equipment and in Manual

The following safety symbols are used inside or on the equipment near operation locations to provide information about safety items and operation precautions. Ensure that you clearly understand the meanings of the symbols and take the necessary precautions BEFORE using the equipment.

This indicates a prohibited operation. The prohibited operation is indicated symbolically in or near the barred circle.

This indicates an obligatory safety precaution. The obligatory operation is indicated symbolically in or near the circle.

This indicates a warning or caution. The contents are indicated symbolically in or near the triangle.

This indicates a note. The contents are described in the box.

These indicate that the marked part should be recycled.

MW9087 Series

Card OTDR

Operation Manual

2	June	2011 (First Edition)
25	September 2020 (12th Edition)

Copyright © 2011-2020, ANRITSU CORPORATION.

All rights reserved. No part of this manual may be reproduced without the prior written permission of the publisher.

The operational instructions of this manual may be changed without prior notice. Printed in Japan

ii

For Safety

			WARNING
		● ALWAYS refer to the operation manual when working near locations
			at which the alert mark shown on the left is attached. If the advice in
			the operation manual is not followed, there is a risk of personal injury
			or reduced equipment performance. The alert mark shown on the left
			may also be used with other marks and descriptions to indicate other
			dangers.
		●	Overvoltage Category
			This equipment complies with overvoltage category II defined in IEC
			61010. DO NOT connect this equipment to the power supply of
			overvoltage category III or IV.
		●	Laser radiation warning
			- NEVER look directly into the cable connector on the equipment
			nor into the end of a cable connected to the equipment. There is a
			risk of injury if laser radiation enters the eye.
			- The Laser Safety label is attached to the equipment for safety use
			as indicated in "Laser Safety" later in this section.
Electric Shock		●	To ensure that the equipment is grounded, always use the supplied
			3-pin power cord, and insert the plug into an outlet with a ground
			terminal. If power is supplied without grounding the equipment, there
			is a risk of receiving a severe or fatal electric shock or causing
			damage to the internal components.
Repair		●	Only qualified service personnel with a knowledge of electrical fire and
			shock hazards should service this equipment. This equipment cannot

be repaired by the operator. DO NOT attempt to remove the equipment covers or unit covers or to disassemble internal components. There are high-voltage parts in this equipment presenting a risk of severe injury or fatal electric shock to untrained personnel. In addition, there is a risk of damage to precision components.

iii

			For Safety
			WARNING
Calibration		● The performance-guarantee seal verifies the integrity of the equipment.
		To ensure the continued integrity of the equipment, only Anritsu service
		personnel, or service personnel of an Anritsu sales representative,
		should break this seal to repair or calibrate the equipment. Be careful
		not to break the seal by opening the equipment or unit covers. If the
		performance-guarantee seal is broken by you or a third party, the
		performance of the equipment cannot be guaranteed.
Falling Over		● This equipment should always be positioned in the correct manner. If
		the cabinet is turned on its side, etc., it will be unstable and may be
		damaged if it falls over as a result of receiving a slight mechanical
		shock.
		Always set up the equipment in a position where the power switch
		can be reached without difficulty.

iv

		For Safety
Laser Safety	Class 1, and 1M indicate the danger degree of the laser radiation
	specified below according to IEC 60825-1:2007.
	Class 1: Lasers that are safe under reasonably foreseeable conditions
		of operation, including the use of optical instruments for
		intrabeam viewing.

Class 1M: Lasers emitting in the wavelength range from 302.5 to 4000 nm that are safe under reasonably foreseeable conditions of operation, but may be hazardous if the user employs optics within the beam. Two conditions apply:

a)for diverging beams, if the user views the laser output with certain optical instruments (for example, eye loupes, magnifiers and microscopes) within a distance of 100 mm; or

b)for collimated beams, if the user views the laser output with certain optical instruments (for example, telescopes and binoculars).

CAUTION

Use of controls or adjustments or performance of procedures other than those specified herein may result in hazardous radiation exposure.

The use of optical instruments with this product will increase eye hazard.

WARNING

The laser in this equipment is classified as Class 1 or 1M according to the IEC 60825-1:2007 standard, and is safe under reasonably foreseeable operating conditions.

Never use optical instruments to directly view Class 1M laser products. Doing so may result in serious damage to the eyes.

v

For Safety

Table 1 Laser Safety Classifications Based on IEC 60825-1:2007

Max.

Pulse

Emitted

Beam

Incorporated

Laser

Model Name

Class

Optical

Width (s)/

Laser

Waveleng

Divergence

Specification

Output

Repetition

Aperture

Power (W)*

Rate

th (nm)

(deg)

(refer to Table

2)

MW9087B

1

0.15

20×10–6/

1650

11.5

a)

Figure 1, [1]

0.019

MW9087D

1M

0.60

20×10–6/

1550

11.5

b)

Figure 1, [1]

0.019

*: Indicates the

possible optical output power when each and every

reasonably foreseeable single-fault condition is included.

Table 2 Incorporated Laser Specification

Incorporated

Max. Optical

Pulse Width (s)/

Emitted

Beam

Output Power

Wavelength

Divergence

Laser

Repetition Rate

(W)*

(nm)

(deg)

a)

< 0.30

20×10–6/0.019

1650

11.5

b)

< 1.20

20×10–6/0.019

1550

11.5

*

Maximum output power is the estimated value when something

breaks down.

vi

For Safety

Table 3 Indication Labels on Product (Ex: Label list)

Type	Sample	Affixed to:	Model Name
1 Explanation		Figure 1, A	MW9087B

2 Explanation

Figure 2, B MW9087D

3

Certification

Figure 2, C

All Models

4

Identification

Figure 2, D

All Models

vii

For Safety

Laser Radiation Markings

A

[1]

Figure 1 Locations of Laser Beam Apertures and Affixed Labels

B C D

Figure 2 Label Locations

viii

Disconnect from Communication

Use in a Residential

Environment

For Safety

CAUTION

The OTDR Module outputs high-power optical pulses. Disconnect the communication equipment from the optical fibers before a measurement, or the optical sensor of the equipment may be broken.

This equipment is designed for an industrial environment.

In a residential environment, this equipment may cause radio interference in which case the user may be required to take adequate measures.

Use in Corrosive	Exposure to corrosive gases such as hydrogen sulfide, sulfurous acid,
Atmospheres	and hydrogen chloride will cause faults and failures.

Note that some organic solvents release corrosive gases.

ix

Equipment Certificate

Anritsu Corporation certifies that this equipment was tested before shipment using calibrated measuring instruments with direct traceability to public testing organizations recognized by national research laboratories, including the National Institute of Advanced Industrial Science and Technology, and the National Institute of Information and Communications Technology, and was found to meet the published specifications.

Anritsu Warranty

Anritsu Corporation will repair this equipment free-of-charge if a malfunction occurs within one year after shipment due to a manufacturing fault, and software bug fixes will be performed in accordance with the separate Software End-User License Agreement, provide, however, that Anritsu Corporation will deem this warranty void when:

●The fault is outside the scope of the warranty conditions separately described in the operation manual.

●The fault is due to mishandling, misuse, or unauthorized modification or repair of the equipment by the customer.

●The fault is due to severe usage clearly exceeding normal usage.

●The fault is due to improper or insufficient maintenance by the customer.

●The fault is due to natural disaster, including fire, wind or flood, earthquake, lightning strike, or volcanic ash, etc.

●The fault is due to damage caused by acts of destruction, including civil disturbance, riot, or war, etc.

●The fault is due to explosion, accident, or breakdown of any other machinery, facility, or plant, etc.

●The fault is due to use of non-specified peripheral or applied equipment or parts, or consumables, etc.

●The fault is due to use of a non-specified power supply or in a non-specified installation location.

●The fault is due to use in unusual environments(Note).

●The fault is due to activities or ingress of living organisms, such as insects, spiders, fungus, pollen, or seeds.

In addition, this warranty is valid only for the original equipment purchaser. It is not transferable if the equipment is resold.

Anritsu Corporation shall assume no liability for damage or financial loss of the customer due to the use of or a failure to use this equipment, unless the damage or loss is caused due to Anritsu Corporation’s intentional or gross negligence.

x

Note:

For the purpose of this Warranty, "unusual environments" means use:

●In places of direct sunlight

●In dusty places

●Outdoors

●In liquids, such as water, oil, or organic solvents, and medical fluids, or places where these liquids may adhere

●In salty air or in place chemically active gases (sulfur dioxide, hydrogen sulfide, chlorine, ammonia, nitrogen dioxide, or hydrogen chloride etc.) are present

●In places where high-intensity static electric charges or electromagnetic fields are present

●In places where abnormal power voltages (high or low) or instantaneous power failures occur

●In places where condensation occurs

●In the presence of lubricating oil mists

●In places at an altitude of more than 2,000 m

●In the presence of frequent vibration or mechanical shock, such as in cars, ships, or airplanes

Anritsu Corporation Contact

In the event of this equipment malfunctions, please contact an Anritsu Service and Sales office. Contact information can be found on the last page of the printed version of this manual, and is available in a separate file on the PDF version.

xi

Notes On Export Management

This product and its manuals may require an Export License/Approval by the Government of the product's country of origin for re-export from your country.

Before re-exporting the product or manuals, please contact us to confirm whether they are export-controlled items or not.

When you dispose of export-controlled items, the products/manuals need to be broken/shredded so as not to be unlawfully used for military purpose.

Reuse parts

Anritsu group promotes recycling activities in order to reuse available resources and save energy. This product may use recycled parts (mechanical components) that conform to Anritsu’s quality standards.

Lifetime of Parts

The life span of certain parts used in this instrument is determined by the operating time or the power-on time. Due consideration should be given to the life spans of these parts when performing continuous operation over an extended period. These parts must be replaced at the customer's expense even if within the guaranteed period described in Warranty at the beginning of this manual.

xii

Crossed-out Wheeled Bin Symbol

Equipment marked with the Crossed-out Wheeled Bin Symbol complies with council directive 2012/19/EU (the “WEEE Directive”) in European Union.

For Products placed on the EU market after August 13, 2005, please contact your local Anritsu representative at the end of the product's useful life to arrange disposal in accordance with your initial contract and the local law.

xiii

Software End-User License Agreement (EULA)

Please carefully read and accept this Software End-User License Agreement (hereafter this EULA) before using (includes executing, copying, installing, registering, etc.) this Software (includes programs, databases, scenarios, etc., used to operate, set, etc., Anritsu electronic equipment, etc.). By using this Software, you shall be deemed to have agreed to be bound by the terms of this EULA, and Anritsu Corporation (hereafter Anritsu) hereby grants you the right to use this Software with the Anritsu specified equipment (hereafter Equipment) for the purposes set out in this EULA.

Article 1. Grant of License and Limitations

1.You may not to sell, transfer, rent, lease, lend, disclose, sublicense, or otherwise distribute this Software to third parties, whether or not paid therefor.

2.You may make one copy of this Software for backup purposes only.

3.You are not permitted to reverse engineer, disassemble, decompile, modify or create derivative works of this Software.

4.This EULA allows you to install one copy of

this Software on one piece of Equipment.

Article 2. Disclaimers

To the extent not prohibited by law, in no event shall Anritsu be liable for direct, or any incidental, special, indirect or consequential damages whatsoever, including, without limitation, damages for loss of profits, loss of data, business interruption or any other commercial damages or losses, and damages claimed by third parties, arising out of or related to your use or inability to use this Software, unless the damages are caused due to Anritsu’s intentional or gross negligence.

Article 3. Limitation of Liability

1.If a fault (bug) is discovered in this Software, failing this Software to operate as described in the operation manual or specifications even though you have used this Software as described in the manual, Anritsu shall at its own discretion, fix the bug, or replace the software, or suggest a workaround, free-of-charge, provided, however, that the faults caused by the following items and any of your lost or damaged data whatsoever

shall be excluded from repair and the warranty.

i)If this Software is deemed to be used for purposes not described in the operation manual or specifications.

ii)If this Software has been used in conjunction with other non-Anritsu-approved software.

iii)If this Software or the Equipment has been modified, repaired, or otherwise altered without Anritsu's prior approval.

iv)For any other reasons out of Anritsu's direct control and responsibility, such as but not limited to, natural disasters, software virus infections, or any devices other than this Equipment, etc.

2.Expenses incurred for transport, hotel, daily allowance, etc., for on-site repairs or replacement by Anritsu engineers necessitated by the above faults shall be borne by you.

3.The warranty period for faults listed in Section 1 of this Article shall be either 6 months from the date of purchase of this Software or 30 days after the date of repair or replacement, whichever is longer.

xiv

Article 4. Export Restrictions

You shall not use or otherwise export or re-export directly or indirectly this Software except as authorized by the laws and regulations of Japan and the United States, etc. In particular, this Software shall not be exported or re-exported (a) into any Japan or US embargoed countries or (b) to anyone restricted by the Japanese export control regulations, or the US Treasury Department's list of Specially Designated Nationals or the US Department of Commerce Denied Persons List or Entity List. In using this Software, you warrant that you are not located in any such embargoed countries or on any such lists. You also agree that you will not use or otherwise export or re-export this Software for any purposes prohibited by the Japanese and US laws and regulations, including, without limitation, the development, design and manufacture or production of missiles or nuclear, chemical or biological weapons of mass destruction, and conventional weapons.

Article 5. Change of Terms

Anritsu may change without your approval the terms of this EULA if the changes are for the benefit of general customers, or are reasonable in light of the purpose of this EULA and circumstances of the changes. At the time of change, Anritsu will inform you of those changes and its effective date, as a general rule 45 days, in advance on its website, or in writing or by e-mail.

Article 6. Termination

1.Anritsu may terminate this EULA immediately if you violate any conditions described herein. This EULA shall also be terminated immediately by Anritsu if there is any good reason that it is deemed difficult to continue this EULA, such as your violation of Anritsu copyrights, patents, etc. or any laws and ordinances, or if it turns out that you belong to an antisocial organization

or has a socially inappropriate relationship with members of such organization.

2.You and Anritsu may terminate this EULA by a written notice to the other party 30 days

in advance.

Article 7. Damages

If Anritsu suffers any damages or loss, financial or otherwise, due to your violation of the terms of this EULA, Anritsu shall have the right to seek proportional damages from you.

Article 8. Responsibility after Termination

Upon termination of this EULA in accordance with Article 6, you shall cease all uses of this Software immediately and shall as directed by Anritsu either destroy or return this Software and any backup copies, full or partial, to Anritsu.

Article 9. Negotiation for Dispute Resolution

If matters of interpretational dispute or items not covered under this EULA arise, they shall be resolved by negotiations in good faith between you and Anritsu.

Article 10. Governing Law and Court of Jurisdiction

This EULA shall be governed by and interpreted in accordance with the laws of Japan without regard to the principles of the conflict of laws thereof, and any disputes arising from or in relation to this EULA that cannot be resolved by negotiation described in Article 9 shall be subject to and be settled by the exclusive agreed jurisdiction of the Tokyo District Court of Japan.

Revision History:

February 29th, 2020

xv

Cautions Against Computer Virus Infection

●Copying files and data

Only files that have been provided directly from Anritsu or generated using Anritsu equipment should be copied to the instrument.

All other required files should be transferred by means of USB flash drive or CompactFlash media after undergoing a thorough virus check.

●Adding software

Do not download or install software that has not been specifically recommended or licensed by Anritsu.

●Network connections

Ensure that the network has sufficient anti-virus security protection in place.

xvi

CE Conformity Marking

Anritsu affixes the CE conformity marking on the following product(s) in accordance with the Decision 768/2008/EC to indicate that they conform to the EMC, LVD, and RoHS directive of the European Union (EU).

CE marking

1. Product Model

Model: MW9087 Series Card OTDR

2. Applied Directive

EMC: Directive 2014/30/EU LVD: Directive 2014/35/EU RoHS: Directive 2011/65/EU

3.Applied Standards

•EMC: Emission: EN 61326-1: 2013 (Class A)

Immunity: EN 61326-1: 2013 (Table 2)

		Performance Criteria*
IEC 61000-4-2 (ESD)		B
IEC 61000-4-3	(EMF)	A
IEC 61000-4-4	(Burst)	B
IEC 61000-4-5	(Surge)	B
IEC 61000-4-6	(CRF)	A
IEC 61000-4-11 (V dip/short)		B, C

*: Performance Criteria

A:The equipment shall continue to operate as intended during and after the test. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the equipment is used as intended.

The performance level may be replaced by a permissible loss of performance. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, either of these may be derived from the product description and documentation and what the user may reasonably expect from the equipment if used as intended.

xvii

B:The equipment shall continue to operate as intended after the test. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the equipment is used as intended.

The performance level may be replaced by a permissible loss of performance. During the test, degradation of performance is however allowed. No change of actual operating state or stored data is allowed. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, either of these may be derived from the product description and documentation and what the user may reasonably expect from the equipment if used as intended.

C:Temporary loss of function is allowed, provided the function is self-recoverable or can be restored by the operation of the controls.

Harmonic current emissions:

EN 61000-3-2: 2014 (Class A equipment)

No limits apply to this equipment with an active input power under 75 W.

•LVD: EN 61010-1: 2010 (Pollution Degree 2)

•RoHS: EN 50581: 2012 (Category 9)

If the third digit of the serial number is "7", the product complies with Directive 2011/65/EU as amended by (EU) 2015/863. (Pb,Cd,Cr6+,Hg,PBB,PBDE,DEHP,BBP,DBP,DIBP)

If the third digit of the serial number is "6", the product complies with Directive 2011/65/EU. (Pb,Cd,Cr6+,Hg,PBB,PBDE)

Third digit

Serial number example

xviii

4. Contact

Name:	Anritsu GmbH
Address, city:	Nemetschek Haus, Konrad-Zuse-Platz 1
	81829 München,
Country:	Germany
Name:	ANRITSU EMEA Ltd.
Address, city:	200 Capability Green, Luton
	Bedfordshire, LU1 3LU
Country:	United Kingdom

xix

RCM Conformity Marking

Anritsu affixes the RCM mark on the following product(s) in accordance with the regulation to indicate that they conform to the EMC framework of Australia/New Zealand.

RCM marking

1. Product Model

Model: MW9087 Series Card OTDR

2. Applied Standards

EMC: Emission: EN 61326-1: 2013 (Class A equipment)

xx

About This Manual

The configuration of the MW9087 Series Card OTDR operation manual is divided into the following three parts: Card OTDR Mainframe, LED Interface, and Password function.

This manual describes the operation/maintenance method for MW9087 Series Card OTDR.

Refer to Chapter 2 "Before Use" to understand the setting of this device and precautions.

Also, refer to Chapter 3 "Measurement Method" to understand the overview of operation flow.

MW9087 Series

Operation Manual

Configuration

MW9087 Series Card OTDR Operation Manual (This manual)

Describes basic operations of MW9087 Series Card OTDR

MW9087 Series Card OTDR

Option 001 LED Interface

Operation Manual

Described the operation method of the LED interface.

MW9087 Series Card OTDR

Password Function Option

Operation Manual

Describes the operation method of the password function.

I

Table of Contents

For Safety ....................................................		iii
About This Manual........................................		I
Chapter 1 Outline .......................................		1-1
1.1	Introduction to MW9087 Series Card OTDR .............	1-2
1.2	Features.....................................................................	1-3
1.3	Outline of OTDR ........................................................	1-5

Chapter 2 Before Use.................................		2-1
2.1	Product Configuration ................................................	2-2
2.2	Names of Parts ..........................................................	2-3
2.3	Installing the Card OTDR...........................................	2-5
2.4	Power Connection .....................................................	2-8
2.5	Communication Settings............................................	2-9
2.6	Installation/Uninstallation for USB Serial Driver ........	2-11
2.7	Confirmation of COM Ports........................................	2-25
2.8	Connecting the Optical Fiber Cable...........................	2-29
2.9	Cautions on Handling Optical Fiber Cables...............	2-31
2.10	Replacing the Optical Connector...............................	2-33
2.11	Precautions................................................................	2-34

Chapter 3 Measurement Method...............		3-1
3.1	Setting before Measurement .....................................	3-2
3.2	Measurement Procedures .........................................	3-3
3.3	Setting Measurement Conditions...............................	3-4
3.4	Measurement.............................................................	3-5
3.5	Waveform Analysis ....................................................	3-6
3.6	Calculation Method ....................................................	3-7
3.7	Obtaining State ..........................................................	3-14

II

Chapter 4 Command Reference................		4-1
4.1	Command Format......................................................	4-2
4.2	Transmission Procedures ..........................................	4-3
4.3	Command List............................................................	4-5
4.4	Command Details ......................................................	4-15
4.5	Error Code .................................................................	4-53
Chapter 5 Performance Test and
	Maintenance..............................	5-1
5.1	Performance Test ......................................................	5-2
5.2	Updating Software .....................................................	5-16
5.3	Cautions on Storage ..................................................	5-17
5.4	Transporting and Disposal.........................................	5-18

Appendix A	Specifications .........................	A-1
Appendix B	Relationship between Pulse
	Width Distance Range............	B-1
Appendix C	Factory Shipment Defaults ....	C-1
Appendix D Command Compatibility ........		D-1
Appendix E	Performance Test Result
	Form ........................................	E-1

1

2

3

4

5

<![if ! IE]>

<![endif]>Appendix

III

IV.

Chapter 1 Outline

This chapter explains the features of the MW9087 Series Card OTDR

1

1.1	Introduction to MW9087 Series Card OTDR .............	1-2
1.2	Features.....................................................................	1-3
1.3	Outline of OTDR ........................................................	1-5

<![if ! IE]>

<![endif]>Outline

1-1

Chapter 1 Outline

1.1 Introduction to MW9087 Series Card OTDR

MW9087 Series Card OTDR is a module form for the optical fiber measurement device.

Figure 1.1-1 Card OTDR Appearance (MW9087B)

This device has multiple models depending on wavelengths and dynamic ranges.

Table 1.1-1 Model Name of Card OTDR

Model	Wavelength	Dynamic range
		(Typ.)
MW9087B	1650 nm	41 dB
MW9087D	1550 nm	50 dB

1550 nm wavelength is used for communications.

To monitor the fiber loss/deterioration or breaks without effects on communications, the model with wavelength of 1650 nm is used.

To measure the fiber loss of the wavelength used for communications, the model with wavelength of 1550 nm is used.

If the fiber loss is large or the communication path has the fiber loss due to optical coupler, the model with a large dynamic range is used.

1-2

1.2 Features

1.2 Features

The MW9087 Series Card OTDR has been developed in order to monitor faults in the optical fiber system.

You can control it via Ethernet; therefore, it can be used for automatic/remote measurement.

Partial sampling

Distance range to be measured can be set, and only the range set can be measured. This feature will shorten the measurement time.

Distance range

Distance range

Measurement range

1

<![if ! IE]>

<![endif]>Outline

Normal measurement

Distance

Partial sampling

Distance

Figure 1.2-1 Normal Measurement and Partial Sampling

SR-4731 file format

The measurement results can be saved with Telcordia standard SR-4731 OTDR Data Format-compliant files. These files have the extension of SOR, and waveforms can be displayed with TraceView software.

This software is available from the following URL.

http://www.anritsu.com/en-US/Downloads/Software/Drivers/Software-Do wnloads/DWL2761.aspx

1-3

Chapter 1 Outline

Figure 1.2-2 Waveform Display with TraceView software

Note

The obtained waveform using the partial sampling cannot be displayed with the Trace View software properly.

1-4

1.3 Outline of OTDR

1.3 Outline of OTDR

OTDR operating principle

OTDR (Optical Time Domain Reflectometer) transmits brief optical pulses to the fiber to measure the intensity and time difference of lights reflected from within the fiber.

The distance of the reflection point is calculated from the time difference, light speed, and index of refraction (IOR) of the fiber.

The light attenuation (fiber loss) is calculated from the light intensity reflected from within the fiber.

OTDR

Fiber

1

<![if ! IE]>

<![endif]>Outline

Time change between the light pulse transmitted and the light level received by OTDR

<![if ! IE]> <![endif]>light			Pulse width
			Measurement time
<![if ! IE]> <![endif]>Transmitted
	<![if ! IE]> <![endif]>level
<![if ! IE]> <![endif]>light
<![if ! IE]> <![endif]>Received		<![if ! IE]> <![endif]>level	Time
			Distance range
	<![if ! IE]> <![endif]>Level
			Distance
			Waveform data of OTDR

Figure 1.3-1 OTDR Transmitted/Received Waveform and

Waveform Data

1-5

Chapter 1 Outline

The maximum measurable distance (distance range) is determined by the time when OTDR measures the received light level after the optical pulse is transmitted.

Transmitted optical pulse is reflected little by little within the fiber. The more distant the reflected light is, the lower is the light level received by OTDR. Therefore, the waveform of measurement result becomes a downward-sloping rectilinear graph.

OTDR fiber measurement

In places where the fiber is connected or damaged, the fiber loss or the light reflection may become larger. These changes make the waveform of measurement result discontinuous.

<![if ! IE]>

<![endif]>Level

Loss occurred

Reflection occurred

Distance

Figure 1.3-2 Detection of Fiber Loss and Reflection

Waveform change with pulse width

The larger is the transmitted optical pulse width, the higher is the received light level. Therefore, make the pulse width larger for the measurement system with large fiber loss such as the case of a long distance range.

<![if ! IE]> <![endif]>Level	When pulse width is large
	Distance

When pulse width is narrow

<![if ! IE]> <![endif]>Level

Distance

Figure 1.3-3 Level Change with Pulse Width

1-6