ANDIG 1131A User manual

https://www.andigsystems.co.in 1
USER MANUAL
OPTICAL TIME DOMAIN REFLECTOMETER
ANDIG SYSTEMS

https://www.andigsystems.co.in 2
Code No--------------------------
(To be allotted by AHSP)
**THE INFORMATION GIVEN IN THIS DOCUMENT IS NOT TO BE
PUBLISHED OR
COMMUNICATED, EITHER DIRECTLY OR INDIRECTLY TO THE PRESS OR TO ANY
PERSON NOT HOLDING AN OFFICIAL POSITION IN THE SERVICE OF THE
GOVERNMENT OF INDIA
USER HAND BOOK
FOR
OPTICAL TIME DOMAIN REFLECTORMETER – MODEL 1131
____________ ______________
(DS Cat No)
** THIS HANDBOOK DOES NOT CONSTITUTE AUTHORITY FOR REPAIRS OR REPLACEMENT OF
COMPONENTS BY USERS. REPAIRS BY DIFFERENT AGENCIES WILL ONLY BE CARRIED OUT AS
LAID DOWN IN PERMISSIBLE REPAIR SCHEDULES PUBLISHED AS EMERs OR EQUIVALENT FROM
TIME TO TIME.
Prepared & Published by
______________________
M/S ANDIG SYSTEMS
34/2, 3rd floor, 10th cross, RajajiNagar
1st N Block, Bangalore 560010
Contact - 080 – 23378976
Email - andig[email protected]

https://www.andigsystems.co.in 3
R E C O R D O F C H A N G E S
Change Notice
No.
Authority
Incorporated by “Name & Rank”
in Block Letters
Initials
with Date
(1)
(2)
(3)
(4)

https://www.andigsystems.co.in 4
SAFETY WARNING
The voltages employed in this Equipment are
NOT high to endanger human life.
POWER
MUST BE SWITCHED OFF
before servicing the equipment
&
GREAT CARE
taken when making internal adjustments etc.
FOR FIRST AID IN CASE OF
ELECTRIC SHOCK SEE OVERLEAF

https://www.andigsystems.co.in 5
FIRST AID IN CASE OF ELECTRIC SHOCK
1.
SWITCH OFF.
If this is not possible, PROTECT
YOURSELF with dry insulating material and pull
the victim clear of the conductor. DO NOT
TOUCH THE VICTIM WITH YOUR BARE HANDS
until he is clear of the conductor, but DO NOT
WASTE TIME.
2.
(a) Place the victim in the sup
ine position.
(b) Keep the air passages clear by turning the
head to one side, opening the patient's mouth
and clearing it of water, saline, mucus or
blood, a lot of which might have accumulated
in the back of the throat. (Figure 1)
3.
4.
If the j
aw is rigid try to force the mouth open
by pressure on the gum behind the last molar
tooth of the lower jaw. When the upper air
passages are thus cleared, tilt the head
backward and force the jaw forwards from
the angles of the jaw in front of the ears. This
would prevent mechanical obstructions to the
upper air passages. (Figure 2-3)
(a) Then hold the chin up and forward with
one hand and pinch the nostrils of the victim
with the other. (Figure 4)
(b) Take a very deep breath and apply your
mouth to that of the victim and blow into his
mouth, until the chest of the victim moves up
indicating filling of the lungs. (NEVER ALLOW
THE CHIN TO SAG). (Figure 4)

https://www.andigsystems.co.in 6
5.
When the chest has moved up, withdraw your
mouth and allow the chest to slink back.
REPEAT this process every three to four
seconds until the victim begins to breathe
again or until he is taken over by a medical
attendant. This method can be continued in an
ambulance during transit of the patient from
the site of accident to the nearest medical
centre.
HAVE SOMEONE ELSE AND SEND FOR A DOCTOR.
KEEP PATIENT WARM AND LOOSEN HIS CLOTHING.
DO NOT GIVE LIQUIDS UNTIL THE PATIENT IS CONSCIOUS.
WARNING
DO NOT REMOVE THE FRONT PANEL & TRY TO REPAIR
THE EQUIPMENT BY ANY UNAUTHORISED PERSON SINCE
LCD IS VERY SENSITIVE PART OF THE EQUIPMENT
WARRANTY WIL BE VOID INCASE OF ANY MAJOR
DAMGE TO THE EQUIPMENT

https://www.andigsystems.co.in 7
This user’s manual explains the features, operating procedures, and handling
precautions of the 1131. To ensure correct use, please read this manual thoroughly
before beginning operation. Keep this manual in a safe place for quick reference
in the event that a question arises.
Notes
 The contents of this manual are subject to change without prior notice as
a result of continuing improvements to the software’s performance and
functionality. The figures given in this manual may differ from those that
actually appear on your screen.
 Every effort has been made in the preparation of this manual to ensure
the accuracy of its contents. However, should you have any questions or
find any errors, please contact ANDIG SYSTEMS
 Copying or reproducing all or any part of the contents of this manual
without the permission of ANDIG SYSTEMS is strictly prohibited.
Trademarks
• In this manual, the ® and TM symbols do not accompany their respective
registered trademark or trademark names.
• Other company and product names are trademarks or registered trademarks
of their respective companies.
ANDIG is a registered trademark & using it without written consent will attract
penalty.
Signalyser software is a proprietary software developed of ANDIG SYSTEMS.

https://www.andigsystems.co.in 8
Congratulations on being a proud holder of INDIA’s 1st & Fully Indigenous OTDR.
We are very proud of our efforts but will always look at user feedback to better
it. Kindly do send your feedback to [e-mail]
WARNINGS & CAUTIONS
WARNING! Do not connect the OTDR to any fiber that is not dark, or that is
terminated by a device with reflectivity > -13 dB.
Please be aware of any APC connector used in the network. APC connectors are
mainly used in long haul & do not produce any reflections that are seen on the
OTDR Screen. APC Connectors are designed to deflect the Fresnel by 7⁰ causing
it to look as a non-reflective splice.
CAUTION!
To avoid serious eye injury, never look directly into the optical outputs of fiber
optic network equipment, test equipment, patch cords, or test jumpers. Refer to
your company’s safety procedures when working with optical systems.
WARNING!
Use only the specified AC adapter. Use of another type of AC adapter can
damage the instrument and create the danger of fire and electrical shock.
WARNING!
 To avoid the danger of fire and electrical shock:
 Never use a voltage that is different from that for which the AC adapter
is rated.
 Do not plug the unit into a power outlet that is shared by other devices.
 Never modify the power cord or excessively bend, twist, or pull it.
 Do not allow the power cord to become damaged. Do not place heavy
objects on the power cord or expose it to heat.
 Never touch the AC adapter while your hands are wet.
 Should the power cord become seriously damaged (internal wiring
exposed or shorted), contact the manufacturer to request servicing.

https://www.andigsystems.co.in 9
CONTENTS
S
.No
Description
Page No
1
System Configuration
10
2
Overview
1. OPM Module
2. VFL Module
3. Optical Laser Source
11 to 13
3
Features
1. Optical Pulse Measurement
2. Optical Pulse Analysis
3. Optical Measurement Principle
14 , 15
4
Measurement Mode
1. Auto Mode
2. Manual Mode
3. Averaged Measurement
4. Display of the distances to breaks after
averaged Measurement
16, 17
5
Optical Pulse Waveform Display
1. Near end Reflection
2. Backscatter
3. Splice Loss
4. Reflection at the Connection Point of Connectors
5. Fresnel Reflection at the Open end of the Fiber
6. Ghost Reflection
18 to 20
6
Trace
Analysis
1. Zooming the Waveform Display Scale
2. Simple Wave Form Display
21
7
Keypad Operations
22
to 2
5
8
Settings & Helpmenu
26 , 27
9
Packing Lis
t & Preparation to Use
28
10
Maintenance / Cleaning Ti
ps
29
11
Warranty
30

https://www.andigsystems.co.in 10
System Configuration :
“ * ” - indicates functionality depending upon model & option chosen
The Model 1131 OTDR can test for breaks, connections, losses, and the like. In
addition, by opting for additional modules, you can use the equipment as an
optical power meter & Copper Cable TDR . The optical light source & visible light
source are standard features.
The OTDR runs on an AC adapter & on internal battery. The AC adapter is
required to charge the internal battery.
Central
Process
Unit
Keypad
Output
Connector
Signal
Conditioning
ADC
OTDR /
OLS unit
VFL unit
Internal
Storage
Power Supply Unit
LCD
Display
OPM
unit *
Printer*
Battery
Copper
TDR
Unit *

https://www.andigsystems.co.in 11
Overview :
There are several types of OTDR units available for different wavelengths,
dynamic ranges, and the like. You can choose the one that suits your application.
Based on user input through the OTDR, the light emitter (LD; laser diode) is driven,
and the generated optical pulse is emitted from the OTDR port into the optical
fiber cable under measurement. The backscatter and reflected light that occur in
the optical fiber cable under measurement returns to the OTDR port. The returned
measurement light is received by the light detector (APD: Avalanche photodiode),
read as a digital signal by the A/D section, subjected to averaging and other
waveform processing, and output to the processor where the OTDR waveform is
displayed.
With the light source option , based on user input through the menu, the light emitter
(LD; laser diode) is driven, and CW or MODULATION light is emitted.
With the optical power option , the communication light (fiber in use) present in the
optical fiber cable under measurement is detected at the OTDR on the same OTDR
port or a separate port ( as customised during purchase ), and its power level is
measured.

https://www.andigsystems.co.in 12
OPM Module:
The measurement light applied to the optical port is received by the light detector
(PD: photodiode), read as a digital signal by the A/D section, and output as
measured values to the mainframe where they are displayed. This is an optional
& additional module that has to be specified during the purchase of the OTDR.
VFL Module:
The VFL (visible light source) module is designed to test for breaks, connections,
losses, and the like in optical fiber networks. The wavelength of the visible light
source is 650 nm. Upon selecting the VFL option in the main menu , the following
sub menu is displayed.
The VFL output selection is via a drop down menu using the “OK” button. The
modulation feature has 270 Hz, 1Khz , 2Khz & VFL blink as options.
VFL blink is set to a timer of 1 sec pulse.
Press “SCAN” to initiate the output.
The output of the VFL is via a dedicated output port on the OTDR equipment.

https://www.andigsystems.co.in 13
Optical Light Source:
The Lasers installed in the OTDR are also set up for further use as a optical light
source with a output of around -7dBm. The OLS feature can be selected from the
main menu & upon selecting the same , the following sub menu is displayed.
User can use the drop down option to select the 1310 or 1550nm lasers.
The modulation feature has 270 Hz, 1Khz , 2Khz as options
The output of the OLS is via the same OTDR output port & there are no separate
/ dedicated port for the same. Press “SCAN” to initiate the output.
The VFL & OLS are standard features of the Model 1131 OTDR

https://www.andigsystems.co.in 14
OTDR Features:
OTDR stands for optical time domain reflectometer. The Model 1131 displays
waveforms that you can use to detect fault locations in optical fiber cables and
monitor fault conditions (transmission loss, splice loss, etc.). It is mainly used in the
following optical fiber cable installation and maintenance situations.
Optical Pulse Measurement :
• Averaged Measurement - A measurement in which measurements are taken
several times and the measured values are averaged to display the result.
• Tabular Display of Results after Averaged Measurement - After averaged
measurement is performed, the OTDR waveform is automatically analyzed, and
the results are displayed in a tabular form below the waveform. Display of the
Distances to Breaks after Averaged Measurement After averaged measurement
is performed, the OTDR waveform is automatically analyzed, breaks (faults) are
detected, and the distances to the breaks are displayed.
• Real-time Measurement - While optical pulse measurement is in progress,
measured values are updated and displayed in real time.
Optical Pulse Waveform Display
• This feature zooms in and out of displayed waveforms and moves waveforms
Optical Pulse Analysis :
• Waveform Analysis
The following events can be analyzed using the 2 cursors / markers.
• Distance
• Splice loss
• Loss per section of the fiber
Analysis is performed over the entire waveform or a section of the waveform using
the following features.
• Up to two waveforms can be displayed simultaneously for comparison.
• The 2 way trace analysis - The waveform measured from one end of the optical
fiber cable and that measured from the other end are combined to verify events
that could not be detected because of dead zones.

https://www.andigsystems.co.in 15
Press the cursor key once to initiate CURSOR 1, Press it again to initiate CURSOR
2. The cursors will indicate the exact location ( will also display the exact enabled
the exact power if enabled during the purchase process ) at the location. The
difference in power & distance is displayed at the top left corner of the screen.
Use the arrow keys to move the cursor right or left. Please note the CURSOR that
is BLINKING is the chosen cursor. Press CURSOR button to alternate between the
two.
• Event Analysis - Events are automatically detected. You cannot edit events and
event lists. Adjustments to the nRef & Threshold can be made if certain events
cannot be detected or when events have mimimal loss.
• Splitter Check – The data from the waveform is checked for various losses & if
the option is marked “ YES” ( default being “NO”) , then the standard losses in
different types of splitters are cross referenced with the actual losses in the events
& splitters are marked as a 1:2 / 1:4 / 1:8 / 1:16 /1:32 / 1:64 splitter as the
case may be. This feature is an optional & an additional feature that is to be
purchased during the initial purchase process.
Optical Pulse Measurement:
The 1131 applies an incident optical pulse to the connected optical fiber cable
and measures the power level of the reflected light from the different sections of
the optical fiber cable such as its connections, bent sections, and the open end of
the fiber. The 1131 uses the measured power level to determine the distance to
the different points (splices, breaks, etc.) of the optical fiber cable and the loss
and other phenomena that occur at those points.
Output Pulse going in to Fiber under test
Reflected Pulse from Fiber to OTDR

https://www.andigsystems.co.in 16
Measurement Mode :
Auto Mode - This is the recommended mode for users who are not familiar with
OTDR operation. In the Auto mode, OTDR parameters such as Range, Pulse Width,
and Averaging Time are set automatically. In addition, Full Auto tests always
include an Event Table and Summary Page. There are measurement conditions
related to measurement resolution—such distance range and pulse width—and
analysis conditions related to the optical fiber cable—such as index of refraction
and backscatter.
The auto mode enables the OTDR to search for events & End of Fiber by using
inbuilt combinations of pulse & averaging times. The default Laser used is the
1310nm & pulse width will vary from 50ns to 500ns for a maximum distance of
20km. If the OTDR cannot find the EOF ( End of FIber ), it will prompt the user to
go to manual mode.
Manual Mode – This is further set into
1. Real time Analysis -This is the best mode for real-time troubleshooting.
2. Manual Mode - This mode is available for experienced users. It
provides the most set up flexibility. You can set Range, Pulse Width,
and Averaging Time manually (Setup = Manual) etc. The user can
select any of the options mentioned in the MANUAL Mode
Averaged Measurement - Averaged measurement is effective when you
want to detect reflections, splice loss, and other faint events that are

https://www.andigsystems.co.in 17
generated from connections or splice points but are buried in noise. The
1131 derives the measured data by averaging the specified number of
optical pulse measurements or by averaging optical pulse measurements
over the specified duration. During averaged measurement, you cannot
change the measurement conditions. You cannot stop an averaged
measurement before it completes. The 1131 offers upto 512K averages
to be conducted which can be converted into a time scale if the user wants
to customise the same.
Display of the Distances to Breaks after Averaged Measurement - The
1131 can perform an averaged measurement and then automatically
search for breaks (faults) in the optical fiber cable or optical line and
display the distances to the breaks on the screen. If there are no faults in
the middle of the optical fiber cable, the end of the cable is detected as
a fault. You can specify the search wavelength or the loss level that is used
to determine the end of the optical fiber cable. You can also zoom the
display scale of the measured waveform and move the display position
Break ( fault )

https://www.andigsystems.co.in 18
Optical Pulse Waveform Display
The optical pulse applied to the optical fiber cable is reflected at different points
of the optical fiber such as its connections, bent sections, and the open end of the
fiber. These sections generate loss. The measured result is displayed as a
waveform that has distance represented in the horizontal direction and loss level
represented in the vertical direction. On the waveform, detected losses or
reflections are known as events.
Near-end Reflection - This is the reflection that occurs at the point where the 1131
and the optical fiber cable are connected. This also includes the 1131’s internal
reflection. In the section where this near-end reflection is detected, even if there
are other connections, the loss and reflections that occur at these points cannot be
detected. This section is the near-end dead zone. When you are measuring a short
distance, connect a launch fiber cable to reduce the effect of the near-end
reflection.
When using an APC OTDR output connector, please note there will NO NEAR END
REFLECTION DUE TO THE NATURE OF THE APC CONNECTOR.
Near End
Reflection
Splice Loss
Reflective Loss
due to connector
Non Reflective Loss
due to macro bend
Reflective loss
at the
end of the fiber.
Dynamic
Range
OFC Cable

https://www.andigsystems.co.in 19
Backscatter : When light travels through an optical fiber cable, Rayleigh scattering
caused by changes in the density of materials that are smaller than the light’s
wavelength and inconsistencies in the fiber's composition generates loss in the
optical fiber itself. The portion of the scattered light that travels in the direction
opposite to the direction of propagation is known as backscatter.
Splice Loss : Because spliced sections of optical fiber cables have a great number
of changes in the material’s density and inconsistencies in the cable’s composition,
loss due to Rayleigh scattering becomes large, and splice loss occurs in these
sections.
Reflection at the Connection Point of Connectors: Using a connector to connect
two optical fibers is different from splicing them together in that a small gap
remains between the two fibers. Because this gap has a different index of
refraction, reflection occurs.
Fresnel Reflection at the Open End of the Fiber : This is the reflection that occurs
at locations where the index of refraction changes (glass to air) such as where
there are tears in the optical fiber cable or at the end of it. When the optical fiber
cable end face is vertical, approximately 3~4% of the incident optical power is
reflected.

https://www.andigsystems.co.in 20
Ghost Reflections: Sometimes you will see a Fresnel reflection where you don't
expect one—usually after the end of a fiber. This usually happens when a large
reflection occurs in a short fiber. The reflected light actually bounces back and
forth within the fiber, causing one or more false reflections to show up at multiple
distances from the initial large (true) reflection. That is, if a large reflection occurs
at 1,325 feet, and there is an unexpected reflection at 2,650 feet (twice the
distance to the first) and another at 3,975 feet (three times the distance to the
first), then it is likely the 2nd and 3rd reflections are "ghosts."
How Secondary Reflections Are Generated The optical pulse that is generated
from position I ( fig below) in the following figure propagates in the direction of II
( fig below). ↓ Light ray A that is reflected at connection II in the figure is reflected
again at connection I and propagates in the direction of II ( fig below) as light ray
B. At this point, the 1131 detects A as an event. ↓ B is again reflected by connection
II, and this generates reflected light ray C. At this point, the 1131 detects C as an
event. Because the 1131 measures all the reflected light rays, A, C, and D, C is
also detected as an event in the same manner that an actually generated reflection
is. Therefore, while there is no actual event in this location, it appears as if an event
has in fact occurred.
OTDR
A
B
C
D
A
C
D
Distance = L
Distance = 2L
Event “C” is a
Ghost Reflection
of A