OWL OWLTrek II WTO2-S13 User manual

Optical Wavelength Laboratories
OPERATIONS GUIDE
OWLTrek II
Optical Time Domain Reflectometer
(OTDR)
Singlemode: WTO2-S15 / WTO2-S13 / WTO2-S35
Multimode: WTO2-M85 / WTO2-M13 / WTO2-M83
OWL-INC.COM
Revision 2A Optical Wavelength Laboratories (OWL)
N9623 West US Hwy 12
Whitewater, WI 53190
Phone: [phone]
Internet: OWL-INC.COM
OWL

This device contains expensive,
This device is to from – avoid dropping this device.
extremely fragile optical fibers, lasers, and photodiodes.
highly susceptible damage impact
WARNING!!!
HANDLE WITH EXTREME CARE!
DO NOT OPEN THIS UNIT!
SENSITIVE POINTS
CRITICAL DAMAGE POINT
Fiber coupling to laser and photodiode
CRITICAL DAMAGE POINT
Fiber crush point near
enclosure's edge.
NOTE: This is an issue for
ALL SIDES of the enclosure
when re-sealing the unit

i
TABLE OF CONTENTS
SECTION 1: INTRODUCTION
Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
About This Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Performance Expectations and Limitations . . . . . . . . . . . . . . . . . 2
Reflective Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Fault Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Fiber Length Measurement . . . . . . . . . . . . . . . . . . . . . . 2
Backscatter Events . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Backscatter Events . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Attenuation Measurement . . . . . . . . . . . . . . . . . . . . . . . 2
Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Eye Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Electrical Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Operational . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Product Label . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Buttons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Indicator LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
SECTION 2: OTDR TESTING
Power ON/OFF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Key OTDR Trace Parameters . . . . . . . . . . . . . . . . . . . . . . . 7
Wavelength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Index of Refraction . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Capture Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Number of Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Dead Zone Length (m) . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Setting Test Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Set Wavelength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Set Index of Refraction. . . . . . . . . . . . . . . . . . . . . . . . . . 8
Setting Trace Options . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Capture Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Pulse Width . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Number of Samples . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Dead Zone Length (m) . . . . . . . . . . . . . . . . . . . . . . . . . 9
Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Starting an OTDR Trace . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Cursor Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
SECTION 3: TRACE ANALYSIS
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Fiber Length Measurement/Link Loss . . . . . . . . . . . . . . . . . . . 12
FiberAttenuation Measurement . . . . . . . . . . . . . . . . . . . . . . 12
Reflectance Measurement . . . . . . . . . . . . . . . . . . . . . . . . 13
Trace Events Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Detector Saturation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
SECTION 1: INTRODUCTION

ii
TABLE OF CONTENTS
SECTION 4: TRACE STORAGE
Stored Readings/Setup Menu . . . . . . . . . . . . . . . . . . . . . . . 15
Saving a Trace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Loading a Previously Stored Trace . . . . . . . . . . . . . . . . . . . . . 16
SECTION 5: OTDR SETUP
Menus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Navigating the Menu System . . . . . . . . . . . . . . . . . . . . . . 17
Setup Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Help Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Operational Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Set Backscatter Coefficient. . . . . . . . . . . . . . . . . . . . . . . . 18
Trace Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Set Length Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
System Information . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
User Information Menu . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Enter User Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Enter Phone Number . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Display Preferences . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Dimness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Brightness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Speaker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Trace Clipping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Power Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Dim Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Standby Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Off Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Utilities Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Set System Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
SetAPD Bias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Format Data Flash. . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Manufacturer Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Factory Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
SECTION 6: OPERATION/MAINTENANCE
Visual Fault Locator (VFL) Operation . . . . . . . . . . . . . . . . . . . . 25
Fiber ID Tone Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Live Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Cleaning the OTDR Port . . . . . . . . . . . . . . . . . . . . . . . . . . 28
SECTION 7: OWLVIEW FOR OTDR SOFTWARE
Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Installing OWLView Software. . . . . . . . . . . . . . . . . . . . . . . . 29
Installing from USB Flash Drive. . . . . . . . . . . . . . . . . . . . . . 29
Installing from Website. . . . . . . . . . . . . . . . . . . . . . . . . . 29
Launching the Software . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Quick-Launch Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Operating the Software . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Downloading Traces from the OTDR . . . . . . . . . . . . . . . . . . . 30
Opening a Stored Trace . . . . . . . . . . . . . . . . . . . . . . . . . 31
Saving Traces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Printing Traces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Printing Multiple Traces . . . . . . . . . . . . . . . . . . . . . . . . . 31
Closing Traces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Working with SOR Files . . . . . . . . . . . . . . . . . . . . . . . . . 32
Exporting SOR Files . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Batch Export SOR Files . . . . . . . . . . . . . . . . . . . . . . . . . 32
Import SOR files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Working with Traces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Button Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Thumbnail View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
SECTION 1: INTRODUCTION

Trace Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Trace Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Event Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Miscellaneous Info . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Status Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Rectangle Zoom . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Zoom In / Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Show / Hide Cursors . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
EventAnalysis / Proper Cursor Placement . . . . . . . . . . . . . . . . 36
Tools Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Update Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Change Length Units . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Invert YAxis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Help Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
SECTION 8: APPENDICES
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Maintenance Information . . . . . . . . . . . . . . . . . . . . . . . . . 37
Repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Battery Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
TABLE OF CONTENTS
SECTION 1: INTRODUCTION

1
SECTION 1: INTRODUCTION
BEFORE YOU BEGIN
All personnel testing optical fibers should be adequately trained in the field of fiber optics before using any fiber optic test equipment.
If the user is not completely familiar with testing fiber optics, they should seek competent training. Such training can be acquired from
a variety of sources, such as local hands-on training classes or online courses.
This is especially true for Optical Time Domain Reflectometers (OTDRs). OTDRs are complicated technical devices, requiring a
great amount of technical skill, knowledge, and expertise to operate. Proper setup and trace interpretation are paramount to a
successful OTDR test, and the consequences of being inadequately trained could result in a significant amount of network down-time
and repair costs.
In addition, OTDRs are delicate scientific instruments, and should be treated as such. Great care should be taken to ensure that all
optical ports are kept clean and free from debris. The reasons for this are two-fold: 1) a clean OTDR produces accurate and precise
results; and 2) if debris is allowed to build up in the OTDR test port, over time connector insertions will grind the debris into the OTDR
port endface, resulting in scratches or “pits” that require extensive and costly repairs.
Valuable information about fiber optic testing can also be gathered from reading printed literature carefully or by thoroughly reading
supplied operations manuals.
The main reason to use an OTDR is to locate faults in an optical fiber that exhibits unacceptable amounts of optical loss, or is no longer
functioning properly. These faults are commonly called “events” and include anomalies such as breaks, shatters, connector
endfaces, patch panels, splices, macro-bends, and micro-bends. By knowing the precise distance to an event, the technician can
determine the nature of the event and quickly restore the network to its former working state.
There are two types of events detectable by an OTDR: Fresnel (reflective) and backscatter (non-reflective).
Fresnel events are caused by “glass-to-air” boundaries in the optical fiber, which causes a high amount of light to be reflected directly
back toward the OTDR. Common Fresnel events include breaks, shatters, connector endfaces, patch panels, or even the end of the
fiber. End-of-fiber detection can also be used to measure the end-to-end length of the fiber.
Backscatter events are caused by the intrinsic properties of the optical fiber. The make-up of the optical fiber scatters the light in all
directions, including a small amount that gets scattered back towards the OTDR. Common backscatter events are splices, (either
fusion or mechanical), macro-bends, and micro-bends. Backscatter can also be used to measure the attenuation (loss) on a certain
section of an optical fiber.
Throughout this manual you will find various symbols that assist with understanding the procedures outlined in this manual. Below is
a list of these symbols and a short description of their purpose:
Helpful tip
Cautionary information
Potentially dangerous condition or operation
ABOUT THIS MANUAL

2
Upholding OWL’s commitment to high-quality, yet affordable, fiber optic test equipment, the OWLTrek II OTDR enables fiber optic
professionals to quickly and easily troubleshoot and locate optical faults in singlemode fibers.
The OWLTrek II is truly a hand-held unit, being one of the smallest OTDRs on the market today – easily able to fit into a shirt pocket –
yet having capabilities of other OTDRs costing thousands of dollars more.
Optical fiber traces are displayed on a high-resolution color LCD display which implements state-of-the-art display technology to
allow the OTDR’s high-resolution color LCD display to “flip” between portrait or landscape mode automatically simply by rotating the
device 90°. By “flipping” from portrait to landscape, the user sees a wider viewing area, displaying more trace information on the high-
resolution color LCD, and allowing for greater viewing detail.
Important OTDR trace parameters such as pulse width, index of refraction, and data point averaging are fully user-configurable, and
are accessible through an intuitive menu system. A minimum of 65 traces using the longest trace distance can be stored in the
OWLTrek II’s internal memory.
Powering the OWLTrek II is a re-chargeable Lithium-polymer battery that allows for hours of normal usage.
The OWLTrek II is equally suited to testing singlemode fibers in many test environments, including LAN, MAN, WAN, FTTH, Telco,
CATV, Manufacturing, and Laboratory.
up to 20
DESCRIPTION
SECTION 1: INTRODUCTION
REFLECTIVE EVENTS
Fault Location. The main function of the OWLTrek II OTDR is to detect the presence of highly reflective events, otherwise known as
Fresnel events, such as breaks, shatters, patch panels, or the end of the fiber link. The distance to an event is shown as a spike on the
OTDR trace, allowing the technician to quickly locate the problem and restore the network.
Fiber Length Measurement. The OWLTrek II can give the operator a general idea of the length of the optical fiber by placing the
cursors at the first and last reflective events, although the last reflective event is not guaranteed to be the end of the fiber. For
example, a severe enough break mid-span could prevent the OTDR from detecting other events beyond the break, or the OTDR trace
could show echoes or ghosts of previous Fresnel events.
BACKSCATTER EVENTS
Backscatter Events. The OWLTrek II has some ability to locate and measure backscatter events. Tweaking pulse-width and
averaging settings may enhance the OWLTrek II’s ability to detect backscatter events. However, even with optimal settings, low loss
backscatter events will become less detectable as the event gets farther away from the beginning of the fiber, especially on longer
fibers.
Backscatter events are also more difficult to measure and interpret. Proper cursor placement is vital to the accurate measurement of
backscatter events. Only individuals with OTDR training and expertise should attempt backscatter event measurement. Interpreting
OTDR traces will be covered in more detail later in this manual.
Attenuation Measurement. Backscatter can be used to measure the attenuation (or loss) of certain sections of an optical fiber by
placing the cursors at the beginning and end of the segment of fiber to be measured.
If available, however, a Power Meter / Light Source (PMLS) test kit or Optical Loss Test Set (OLTS) should always take precedence
over an OTDR for end-to-end attenuation measurements.
PERFORMANCE EXPECTATIONS AND LIMITATIONS

3
PRECAUTIONS
SECTION 1: INTRODUCTION
LABEL INFORMATION
On the back of each OWLTrek II OTDR is a label similar to the one shown here containing model
number, serial number, power requirements, and special cautionary information.
OTDR port Class 1M Laser Output
VFL port Class 2 Laser Output. Do NOT stare into beam.
USB port 6VDC, 1A
Directive 2002/96/EC of 27 January 2003 on waste electrical
and electronic equipment (WEEE)
EU Directives EN 61326-1:2006 (EMC) and EN 61010-1:2001 (Safety)
OTDR: Class 1M Laser Output
VFL: Class 2 Laser Output
Do NOT stare into beam.
IEC 60825
Power: 6VDC, 1 A
Eye Safety
look into the connector port of any fiber optic test or transmission equipment, patch cable, fiber link, or other
installed fiber. Always assume that active laser equipment is attached to optical fibers, and is powered on.
Do not run a test on the OTDR unless it is connected to the fiber under test, or the dustcap is firmly in place.
Electrical Safety
Only use appropriate AC adapters for charging this device. Use of inappropriate power adapters could cause damage to
the device, and could cause harm to the user from fire and electrical shock.
Operational
eep connector ferrules and optical connector ports clean to prevent irreparable damage to the OTDR port. For best
results, replace dust caps after each use.
Connector
do NOT insert APC (Angled Physical Contact) connectors into the OTDR port.
Service
NEVER
K
For best results,
There are no user-serviceable parts in this device. Unauthorized attempts to service this product will void the product
warranty.
WARNING
ASSEMBLED IN USA
Optical Wavelength Laboratories
Whitewater, WI 53190 • 262-473-0643
MODEL#: WTO2-S15
SERIAL#: WTOH100001
This product complies with the
following EU Directives:
EN 61326-1:2006
EN 61010-1:2001
OTDR: Class 1M Laser Output
VFL: Class 2 Laser Output
Do NOT stare into beam.
Output Type: FP Laser
Output 8: 1550nm
Power: 6VDC, 1 A
IEC 60825

Menu Buttons – activates the associated
menu option
Navigation Buttons – moves cursors or
menu options in the direction of the button, or
are used to zoom in or out on cursor
placement
Power Button – powers the OTDR on; press
and hold to power off; also, while the OTDR is
on, brief press will activate other functions
Enter Button – from the trace screen, this
button changes the function options menu at
the bottom of the screen. Also activates
menu options while in the menu system
4
PORTS
BUTTONS
Visual Fault Locator Port (VFL) – Visual Fault Locator port
for troubleshooting
USB Download Port ( ) – downloads data from the
OTDR to the PC for software trace analysis and digital data
storage; also used for battery charging
OTDR Port (OTDR)– connects the OTDR to the fiber under
test
Reset Button – resets the OTDR in case of malfunction
SECTION 1: INTRODUCTION
06086m
20226m
24718m
RFL dBx
-81.00x
14140
dB
2.43x
3.34x
L mx
Fiber #x
TESTZOOMLOCKCURSOR
ENTER
AUTO
1550nm
VFL OTDR

5
Fiber ID – name of the currently loaded fiber trace
OTDR Test Mode – shows which test mode the OTDR
is in –AUTO, USER, SEMI, or FILT
VFL Indicator – shows the current VFL mode: blank =
OFF; = ON continuous; = ON flashing
Zoom Indicator – displays “H” for horizontal zooming,
and “V” for vertical zooming
Battery Life Indicator – displays the remaining
battery life
Trace Viewing Area – displays the results of the
OTDR trace(s), which users can zoom in on for more
detailed trace analysis
Trace Wavelength – shows the wavelength(s) of the
traces displayed in the trace viewing area. The active
trace wavelength will be listed on the left.
If more than one wavelength is present, the color of the trace corresponds with the color of the wavelength number
Trace Information – displays the relative position and power levels at and between the red and green cursors for the
currently active trace.
Function Options Menu – displays the on-screen menu options for trace control
There are three sets of Function Options Menus. The Enter key ( ) is used to toggle between these three menus:
red pink
DISPLAY
SECTION 1: INTRODUCTION
TEST
ZOOM
LOCK
CURSOR SETUP
INDEX
LOADSAVE MENU WAVE EOFEVENTS
MENU 1 MENU 2 MENU 3
NOTE: the WAVE option will only be
displayed if more than one wavelength
is present
06086m
20226m
24718m
RFL dBx
-81.00x
14140
dB
2.43x
3.34x
L mx
Fiber #x
TESTMENULOCKCURSOR
ENTER
1550nm
AUTO H

6
SECTION 1: INTRODUCTION
CHARGING STATUS – will be lit when charging through a
transformer or USB port
battery fully charged
battery charging
problem with battery and/or charger; contact OWLfor service
STANDBY STATUS
Normal operation blinking
STANDBY solid; press any key to “wake up” the device
GREEN
GREEN
ORANGE
RED
RED
INDICATOR LEDs
Fiber #xAUTO

7
KEY OTDR TRACE PARAMETERS
SECTION 2: OTDR TESTING
POWER ON/OFF
POWER ON
Press to power on the OTDR.
When the OTDR has completed startup, the trace area will either be blank, as shown at right,
or will show the previously viewed trace.
Continue below for more information about running a new OTDR trace.
POWER OFF
The OTDR may be powered off from any screen by holding .
Below is a descriptive list of key OTDR trace parameters.
WAVELENGTH – range of values: Multimode: 850, 1300, BOTH; Singlemode: 1310nm, 1550nm, BOTH. Allows the user to
select one or two wavelength(s) used for testing. Wavelength selection only applies to dual-wavelength OTDR.
INDEX OF REFRACTION – range of values: 1.4000 to 1.6000. To ensure the most accurate distance to events, Index of Refraction
(IoR) should be set to the fiber manufacturer’s refractive index specification for the fiber under test. If unknown, set IoR to:
SINGLEMODE – 1.4681 (as this value falls within 99% of the IoR values for most singlemode optical fibers)
MULTIMODE – 1.4920
CAPTURE MODE – range of values: AUTO, SEMI, USER, FILT, LIVE.
AUTO all trace options are determined automatically, except dead zone length.
SEMI same asAUTO except the pulse width is not automatically determined.
USER all user configured options are used when capturing the trace.
FILT same as USER plus the software will filter (smooth) the trace to remove noise. This will help produce a cleaner
trace with less averaging required.
LIVE uses the user-defined trace settings to continuously update the trace on the screen. The trace will be updated
after the user-defined number of averages is completed. The cursors and zoom functions work in LIVE mode. To
start and exit LIVE mode, press the TEST function button.
NOTE: if connected to a PC running OWLView software, LIVE mode also updates the software trace area
PULSE WIDTH – range of values: Multimode: 1, 2, 5, 10, 20, 50, 100 m; Singlemode: 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000 m.
Pulse width offers a trade-off between the ability to measure longer cable distances (longer pulse width) versus the ability to see two
events that are closely spaced (shorter pulse width). This is otherwise known as an OTDR’s event dead zone (i.e. the minimum
distance between two events where they both can be measured).
NUMBER OF SAMPLES – range of values: 256, 512, 1024, 2048, 4096. Increasing the number of samples allows the OTDR to
have better display resolution (events are easier to see, especially near the noise level), but also increase the trace acquisition time.
DEAD ZONE LENGTH(m) – range of values: 0 to 1500. Allows the user to enter the length of a dead-zone box (a.k.a. pulse
suppressor), if one is being used. If a value is entered for dead zone, the dead zone portion of the OTDR trace will be grayed out. The
active portion of the trace will begin where the dead zone ends.
RANGE – range of values: 1, 2, 5, 10, 25, 50, 65, 128 km. Allows the user to manually enter the total length of the trace. NOTE: for
best results, this value should be set to the next highest value from the actual length of the fiber under test.
STEP – range of values: 1, 2, 4 m. Trace sample spacing. Smaller steps produce more accurate distance to events, but trace
acquisition takes longer.
06081m
20221m
24711m
RFL dBx
-81.00x
14140
dB
0.00
0.00
L mx
Fiber #x
TESTZOOMLOCKCURSOR
ENTER
AUTO
1550nm

SET INDEX OF REFRACTION
To set the index of refraction, press from the trace screen until the following menu
options appear:
allows the user to change the index of refraction; setting will appear at
the top of the trace screen. Press key again to exit.
Index of refraction should be set to the optical fiber manufacturer’s index of refraction
specification. If unknown, use the suggested values below.
Suggested index of refraction values:
SINGLEMODE – 1.4681
MULTIMODE – 1.4920
INDEX
8
SECTION 2: OTDR TESTING
SETTING TEST PARAMETERS
SET WAVELENGTH
When using a dual-wavelength OTDR, traces can be run at either one or two wavelengths.
To set the trace wavelength(s), press from the trace screen until the following menu
options appear:
allows the user to select one or both wavelengths to be used for testing.
Arrow keys scroll through three options: 1310nm, 1550nm, BOTH.
Press key again to exit.
The selected wavelength(s) will appear at the bottom of the trace screen. If two wavelengths
are present on the trace screen, they will be displayed as either or .
The cursor information below the trace screen applies to the wavelength listed in .
If the OTDR only has one wavelength installed, the WAVE option will not appear.
blue
blue
brown
WAVE
SETUP
INDEX
LOADSAVE
MENU WAVE
EOFEVENTS
06081m
20221m
24711m
RFL dBx
-81.00x
14140
dB
0.00
0.00
L mx
Wave: 1550nmxxx
WAVE
MENU
EOFEVENTS
ENTER
AUTO
1310nm 1550nm
06081m
20221m
24711m
RFL dBx
-81.00x
14140
dB
0.00
0.00
L mx
Index 1.4681xxx
SETUPINDEXLOADSAVE
ENTER
AUTO
1310nm 1550nm

SETTING TRACE OPTIONS
To see an additional menu of trace options, press from the trace
screen until the following menu options appear:
opens the TRACE OPTIONS menu
selects the next or previous trace option
changes the value in the selected trace option
CAPTURE MODE – Range of values: AUTO, SEMI, USER, FILT, LIVE
Capture Mode should be set to AUTO mode for a majority of testing
scenarios, so the OTDR can automatically determine the best set of trace
parameters based on the fiber link under test.
USER, SEMI, FILT, and LIVE require the user to understand
the consequences of setting trace parameters manually.
Only trained fiber optic professionals who are experienced with operating OTDRs should manually set trace parameters.
Suggestions for setting these parameters are given below.
PULSE WIDTH – range of values: Multimode: 1, 2, 5, 10, 20, 50, 100 m; Singlemode: 1, 2, 5, 10, 20, 50, 100, 200, 500, 1000 m.
Pulse width should be set to the shortest setting that allows multiple closely-spaced events to be clearly defined, while preventing any
of the trace from reaching the noise floor.
NUMBER OF SAMPLES – Range of values: 256, 512, 1024, 2048, 4096. Use the maximum number of samples unless traces are
taking to long to acquire.
DEAD ZONE LENGTH (m) – Range of values: 0 to 1500. Set this value to ‘0000’ if not using a dead-zone box (a.k.a. pulse
suppressor box). If using a dead-zone box, and you want to highlight the dead-zone box length on the trace, enter the length of the
dead-zone box in meters.
RANGE – range of values: 1, 2, 5, 10, 25, 50, 65, 128 km. Set to the next highest value from the actual length of the fiber under test.
If fiber length is unknown, select MAX km.
STEP – Range of values: 1, 2, 4 m. Use shortest STEP value for most accurate distance to events, unless trace acquisition time is
too long.
SETUP
9
SECTION 2: OTDR TESTING
SETTING TEST PARAMETERS, cont.
SETUP
INDEX
LOADSAVE
TRACE OPTIONS
CAPTURE MODE
PULSE WIDTH
NUMBER OF
SAMPLES
DEAD ZONE
LENGTH(m)
RANGE
STEP
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XX XXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
XXSAVEXXXXQUITXXXXHELPXXXXXXXXXXXX
SAVE QUIT HELP
AUTO
1m
4096
1100
MAXkm
1m

Once the OTDR parameters have been set, an OTDR trace can be run. Press from the
trace screen until the following menu options appear:
starts an OTDR trace based upon the current OTDR parameters
During the OTDR test (as shown at right):
!theABORT soft-key appears (used to abort an OTDR trace)
!all soft-keys are disabled
!a bar graph appears at the top of the screen showing the progress of the OTDR test
!dual-wave test will run a separate trace automatically for each wavelength
starting a new trace will replace the old trace on the display with the new trace after a few seconds (depending upon the
trace length).
TEST
10
STARTING AN OTDR TRACE
Once the OTDR trace is complete, the OTDR trace will appear on the screen, and the OTDR
information – distance and optical power – will be updated.
Trace information is color-coded. and refer to the cursors. text refers to the
difference between the two cursors. text refers to the perceived end of the fiber link.
sets the active cursor – no cursor, , , or both and
locks the active cursor at its current location; unlocks a locked cursor
When a cursor is locked, a colored padlock symbol will appear next to
the appropriate cursor information
sets the ZOOM mode to Horizontal (H) or Vertical (V)
WHEN ONE OR MORE CURSORS ARE SELECTED: moves the cursor(s) left or right; holding these buttons
speeds up the cursor movement
WHEN NO CURSOR IS SELECTED: screen pans left and right
WHEN ONE OR MORE CURSORS ARE SELECTED: zooms in or out on the active cursor(s)
WHEN NO CURSOR IS SELECTED: zooms in and out on the center of the screen
two color coded traces will appear on the screen if a dual-wavelength trace was run
Red
red red
green
green green
Blue
Orange
LOCK
LOCK
ZOOM
CURSOR NAVIGATION
SECTION 2: OTDR TESTING
06081m
20221m
24711m
RFL dB
x
-81.00
14140
dB
0.00x
0.00x
L mx
TESTING
ABORT
1550nm
06086m
20226m
24718m
RFL dBx
-81.00
14140
dB
2.34
3.43
L mx
Fiber #x
CURSOR LOCK ZOOM TEST
ENTER
AUTO
1550nm
TEST
ZOOM
LOCK
CURSOR

SECTION 3: TRACE ANALYSIS
This section will provide a basic overview about how to analyze an OTDR trace, and will cover the different types of information that
can be gathered from an OTDR trace, including:
– event location;
– fiber length measurement;
– fiber attenuation (loss); and
– reflectance measurement.
proper interpretation of OTDR test results requires a significant amount of technical skill, knowledge, and expertise. Proper
trace interpretation is paramount to a successful OTDR test, and the consequences of interpreting a trace incorrectly could
result in a significant amount of network down-time and repair costs.
OVERVIEW
11
The primary function of an OTDR is to locate events along the optical fiber. On
an OTDR trace, events appear as deviations from an otherwise gently sloping
line.
Below is a list of the different events shown in the example at right, including the
type of event, and possible interpretations of the data:
Fresnel end of dead-zone box (pulse suppressor)
Fresnel patch panel using flat polish connectors
Backscatter fusion splice or macro-bend
Fresnel patch panel usingAPC (angled physical contact)
connectors
Fresnel end of fiber link; could also indicate a severe
break where no other events can be detected
after the break
the slope of the trace appears to “dip” to a lower level after the event
(events 1, 2, and 3), this could mean one of two things: 1) if the slope
of the line changes, the refractive index of the fiber preceding the
event is different from the refractive index of the fiber following the event, or 2) if the slope stays the same, then the event is
simply a loss-inducing event.
CURSOR PLACEMENT
Proper cursor placement is critical in determining the exact distance to an event, as well as the relative effect the event has on optical
power traveling through the event.
The cursor should be placed right before the slope of the line begins to spike.
The cursor should be placed after the event, at a point where the slope of the line returns to the normal backscatter level.
The trace information (located below the trace) will show the distance and relative power (in dB) at the point where each cursor is
placed.
If
Tall spikes usually indicate flat polish connections or other highly reflective events (breaks, shatters, end of fiber, etc.), while
short spikes usually indicate angled polish connections.
red
green
EVENTS
06086m
6126m
24718m
RFL dBx
-34.26
40
dB
0.34
7.43
L mx
Fiber #x
CURSOR LOCK ZOOM TEST
ENTER
AUTO
1550nm

SECTION 3: TRACE ANALYSIS
12
By placing the cursors at the beginning and ending points of the fiber trace, the
distance between the cursors will show a close approximation of the total length
of the optical fiber link, as well as a close approximation of the total fiber link
loss.
CURSOR PLACEMENT
Proper cursor placement is necessary to determine the end to end length and
link loss of an optical fiber link. Refer to the diagram at right when placing
cursors for fiber length measurement.
The cursor should be placed directly before the first reflective event,
before the slope of the line begins to spike.
The cursor should be placed directly before the last event, before
the slope of the line begins to spike.
The trace information (located below the trace) will show the distance and
relative power (in dB) at the point where each cursor is placed, as well as the
total link distance and end-to-end link loss.
In this example, the total link length is , and the end-to-end link
loss is .
red
green
24718 meters
7.43 dB
FIBER LENGTH MEASUREMENT/LINK LOSS
The fiber attenuation, or loss, for a certain section of an optical fiber link can be
determined by placing the cursors at the beginning and end points of the
segment of fiber under test.
CURSOR PLACEMENT
Proper cursor placement is necessary to determine the attenuation of a certain
segment of fiber.
The cursor should be placed at the beginning of the section of fiber
under test.
The cursor should be placed at the end of the section of fiber under
test.
The trace information (located below the trace) will show the distance and
relative power (in dB) at the point where each cursor is placed, as well as the
loss and distance of the section of fiber being analyzed.
In this example, the section of fiber being analyzed has of loss, and is
.
Using this information, dB per kilometer can also be calculated, which can be
compared to the fiber manufacturer attenuation specification. To determine
dB/km:
1.76 dB / 7.040 km = 0.25 dB/km
n the example shown here, the attenuation measurement also includes the loss through the connector located near the red
cursor.
red
green
1.76 dB
7040 meters
I
FIBER ATTENUATION MEASUREMENT
1m
24719m
24718m
RFL dBx
-81.00
24718
dB
7.43
7.43
L mx
Fiber #x
CURSOR LOCK ZOOM TEST
ENTER
AUTO
1550nm
4086m
11126m
24718m
RFL dBx
-34.26
7040
dB
1.76
7.43
L mx
Fiber #x
CURSOR LOCK ZOOM TEST
ENTER
AUTO
1550nm

SECTION 3: TRACE ANALYSIS
13
The reflectance of a specific event can be determined by placing the cursors on
either side of an event. The OTDR will show the reflectance in dB of the highest
reflective event between the cursors.
CURSOR PLACEMENT
Proper cursor placement is important when determining the reflectance of a
reflective event.
The cursor should be placed on the backscatter line directly before the
event, on the sloping line before the spike.
The cursor should be placed on the backscatter line somewhere
after the event.
Make sure that only one reflective event is included between the
cursors.
The trace information (located below the trace) will show the reflectance (in dB)
of the highest reflective event between the cursors.
In this example, the reflective event being measured has a reflectance of
.
red
green
-34.26
dB
REFLECTANCE MEASUREMENT
Automatic event location can be performed from the trace screen by accessing the
function option. See page 5 for more information about function option menus.
LOCATION the distance to the start of the event
TYPE type of event (reflective, loss, etc.)
REFL reflectance of the event
LOSS loss of the event
moves the cursor up and down in the list of detected events
returns the user to the trace screen, zoomed in on the selected event
displays the next page of events, if there are more events than will fit on the screen
returns the user to the trace screen
Once an event has been selected from this menu, each individual event will be marked with a “tic” mark at the top of the trace area.
The type of event is denoted by color: black for loss events and for reflective events.
IMPORTANT NOTE: automatic event location is only meant to be used as a
guideline for the location of possible events. It is ultimately up to the user to
verify and determine if an event actually exists at that location.
light blue
EVENTS
VIEW
PAGE
DONE
TRACE EVENTS
Location
14m
24011m
50539m
xxxx
x
x
Type
REFL
LOSS
REFL
Refl
-47.38
-81.00
-17.54
Loss
0.87
0.21
-11.63
X
X
VIEW PAGE DONE
TRACE EVENTS MENU
4786m
6126m
24718m
RFL dBx
-34.26
1340
dB
0.52
7.43
L mx
Fiber #x
CURSOR LOCK ZOOM TEST
ENTER
AUTO
1550nm1550nm

SECTION 3: TRACE ANALYSIS
14
Some highly reflective events are so reflective that they “over-drive” the OTDR
circuitry, and cause the OTDR graph to appear as if the trace completely drops
out.
This issue is called “saturation inversion”, and only appears when overly-
reflective light causes the internal OTDR circuitry to become saturated.
Every OTDR suffers from saturation issues, and many high-end OTDRs
include additional circuitry that tries to quench the saturation as it occurs.
However, irregardless of how well an OTDR can quench the saturation, the fact
remains that the reflective event requires immediate attention.
TRACE ANALYSIS
The sample trace shown here shows what typical saturation inversion looks
like. Four key points have been noted on the trace to explain what is occurring
in the OTDR:
1) The red line at the top of the reflective peak shows that the
OTDR has been saturated (please note that when the peak
has a red line, the reflectance value is not being reported
properly);
2) The flat line at the bottom of the trace shows that the OTDR has been “over-driven”, and has inverted the trace;
3) The OTDR has begun its recovery from saturation;
4) The OTDR has fully recovered from saturation, and has returned to its normal backscatter line.
In this example, the reflective event is caused by the interconnection that occurs between two connectors at a patch panel. The
connectors on either side of the patch panel are PC (physical contact).
There are several ways to address highly reflective events like this:
a) Thoroughly clean and inspect both connectors for debris or damage;
b) If the connectors appear damaged after thorough cleaning, try re-polishing the connector endfaces;
c) Re-terminate using connectors with better reflectance values (typical values shown here);
PC (physical contact) -30 to -35 dB
UPC (ultra physical contact) -45 to -50 dB
APC (angled physical contact) -55 to -60 dB (or less)
d) Replace the mating sleeve in the patch panel.
Once the inverted event has been fixed, re-test the fiber to ensure the event is no longer overly reflective.
ANOTHER HELPFUL TIP
Another helpful tip for mitigating reflectance comes from the Fiber OpticAssociation (FOA) website:
http://www.jimhayes.com/OTDR/otdrs_d.htm
found under the section titled This "Trick" Can Help. This tip refers to the use of index-matching fluid between connectors to help
eliminate the air gap causing the overly reflective event.
SATURATION INVERSION
4786m
6126m
24718m
RFL dBx
-30.26
1340
dB
0.52
7.43
L mx
Fiber #x
CURSOR LOCK ZOOM TEST
ENTER
AUTO
1
2
3
4

sets the Function Options Menu to allow access to Data Storage and Setup Menu
options. The following soft-keys apply to data storage functions.
SAVINGATRACE
LOADINGAPREVIOUSLY STORED TRACE
SAVE
LOAD
15
STORED READINGS
Traces may be stored in permanent memory for later viewing or download to hard disk for
data file retrieval.
From the trace screen, press to enter the fiber name and save the currently
displayed trace to memory.
To enter a fiber name, use the arrow keys to highlight the appropriate character on the grid.
BACKSPACE
TOGGLE BETWEEN UPPERAND LOWER CASEALPHABET
FORWARD SPACE
SELECTTHE HIGHLIGHTED CHARACTER
FINISHED ENTERING NAME
SAVE
<--
SHIFT
SPACE
DONE
SAVING A TRACE
SECTION 4: TRACE STORAGE
06086m
20226m
24718m
RFL dBx
-81.00
14140
dB
2.34
3.43
L mx
Fiber #x
SAVE LOAD INDEX SETUP
ENTER
AUTO
Enter fiber name:x x
Fiber #x
ABCDEFGHIJKLM
NOPQRSTUVWXYZ
0123456789 : ; <
<-- SHIFT SPACE DONE
Use arrows to highlight letter
then press the enter key. Tap
the power button to abort.
1550nm