113
SVPRIBOR OPTICAL REFLECTOMETER (OTDR) GAMMA-LITE User’s Guide TVER
SVPRIBOR
OPTICAL REFLECTOMETER (OTDR) GAMMA-LITE User’s Guide
TVER
2
3
TABLE OF CONTENTS
GENERAL INFORMATION........................................................................... 6
PURPOSE....................................................................................................... 6 CERTIFICATES............................................................................................... 6 ENVIRONMENT ............................................................................................. 6 SPECIFICATIONS............................................................................................ 6 DELIVERY SET.............................................................................................. 9 SAFETY CONSIDERATIONS ............................................................................ 9 INSTRUMENT DESIGN.................................................................................... 9
PRINCIPLE OF OTDR OPERATION......................................................... 12
GETTING STARTED AND SWITCHING ON THE INSTRUMENT..... 13
POWER SUPPLY OF THE INSTRUMENT ......................................................... 15
MAIN MENU OF THE INSTRUMENT....................................................... 16
HOW TO WORK WITH TOUCH SCREEN............................................... 17
APPLICATION SELECTION ........................................................................... 17 BUTTON PRESSING...................................................................................... 18 HOW TO SELECT FROM THE LIST ................................................................ 19 [F] BUTTON................................................................................................ 20
OPTICAL REFLECTOMETER (OTDR).................................................... 21
HOW TO CONNECT THE OPTICAL FIBER...................................................... 21 MAIN SCREEN............................................................................................. 22
Buttons for calling special functions ................................................. 23 Operating control buttons.................................................................. 23 Information field ................................................................................ 24 Full-screen mode................................................................................ 24
STARTING THE MEASUREMENT PROCESS.................................................... 25 Starting the measurement process without data averaging............... 26 Starting the measurement process with data averaging.................... 26
TRACE MANIPULATION............................................................................... 27 Cursors manipulation ........................................................................ 27 Zoom................................................................................................... 30 Scrolling ............................................................................................. 32 Map .................................................................................................... 33 Distance measurement ....................................................................... 34 Smart marker (marker) ...................................................................... 35 2-point attenuation measurement in OF (2P losses) ......................... 41 Long attenuation measurement (LSA-line) ........................................ 42 Attenuation measurement in OF connections (LSA-losses)............... 43 Reflectance measurement (reflection)................................................ 44
4
Optical return loss measurement (ORL)............................................ 45 PARAMETER SETTINGS ............................................................................... 46
Measure parameters .......................................................................... 47 Analysis parameters........................................................................... 48 Miscellaneous .................................................................................... 49
AUTOMATIC ANALYSIS .............................................................................. 50 Landmarks on the trace ..................................................................... 51 Event Table ........................................................................................ 52 Operator's work with markings ......................................................... 53
HOW TO WORK WITH MEMORY.................................................................. 54 Purpose of functional buttons ............................................................ 55 How to load trace for viewing and comparing.................................. 56 How to create folder .......................................................................... 57 How to save current trace.................................................................. 58 How to move trace in the folder......................................................... 60 How to work with external memory (USB flash) ............................... 60
MASS MEASUREMENTS OF TRACES ............................................................ 62 Operating procedure.......................................................................... 62
HOW TO CONTROL THE FIBER WELDING PROCESS ..................................... 66 Operating procedure.......................................................................... 66
VISUAL FAULT LOCATION....................................................................... 67
HOW TO CONNECT THE FIBER .................................................................... 67 LASER CONTROL ........................................................................................ 68
AUTOMATIC MEASUREMENT................................................................. 70
HOW TO CONNECT THE FIBER .................................................................... 71 RUNNING MEASUREMENTS......................................................................... 72
TEST STATION.............................................................................................. 77
CHECKING LINE FOR COMPLIANCE WITH TEMPLATE .................................. 77 CREATING TEMPLATES ............................................................................... 81 CREATING A TEMPLATE FROM PREVIOUS MEASUREMENTS........................ 82 LINE DAMAGE AND LINE MONITORING ...................................................... 82 SAVING RESULTS........................................................................................ 84
PING ................................................................................................................. 85
CONNECTION TO LINE ................................................................................ 85 PINGING...................................................................................................... 86 IPTV TEST ................................................................................................. 89
SETTINGS ....................................................................................................... 91
DATA EXCHANGE AND REMOTE CONTROL...................................... 94
DATA EXCHANGE WITH PC ........................................................................ 94 REMOTE CONTROL VIA TCP/IP .................................................................. 95 FILE MANAGER .......................................................................................... 96
5
MAINTENANCE........................................................................................... 100
STORAGE RULES ....................................................................................... 100
TRANSPORT................................................................................................. 100
INFORMATION ABOUT PRECIOUS METALS CONTENT ............... 100
INSTRUMENT CALIBRATION ................................................................ 101
VERIFICATION STAGES ............................................................................. 101 CALIBRATION TOOLS................................................................................ 101 CALIBRATION ENVIRONMENT................................................................... 102 CALIBRATION PROCEDURE ....................................................................... 102
External examination and testing .................................................... 102 Dynamic range estimation ............................................................... 103 Deadzone estimation ........................................................................ 105 Attenuation calibration .................................................................... 108 Distance calibration......................................................................... 110
CALIBRATION INTERVAL .......................................................................... 111
MANUFACTURER'S WARRANTY .......................................................... 112
ACCEPTANCE CERTIFICATE ................................................................ 112
6
GENERAL INFORMATION
Purpose Optical time domain reflectometer GAMMA-LITE (hereinafter "OTDR") is
designed to measure the attenuation in optical fibers (OF) and their connections, OF length and distance to places of events in the optical cable and in OF in the fiber-optic transmission systems.
The OTDR can be used in the manufacture of optical fibers and optical cables, as well as in the installation and operation of fiber-optic lines for control of cables and prediction of faults in them. OTDR can be operated in laboratory and field conditions.
As an additional option the instrument contains a laser light source at a wavelength of 650 nm for visual detection of OF damage (VFL - Visualizer).
Certificates Public register No. 40717. Certificate of measuring device type approval
RU.C.37.003.A No. 35446.
Environment
• Ambient air temperature from minus 10 to plus 50 °С; • Relative air humidity max. 90 % by 25 °С; • Atmospheric pressure from 70 to 106,7 kPa.
Specifications
• Wavelength of optical radiation at the OTDR output: o 1,31 ± 0,02 / 1,55 ± 0,02 µm.
• Ranges of measured distances for single-mode optical fiber:
o 0,3; 0,5; 1; 2; 5; 10; 25; 50; 75; 100; 160 km.
• OTDR allows setting the values of the probe pulse width in the range of: o 8÷20 000 ns.
• Deviations of probe pulse width do not exceed:
o plus 50 % and minus 20 % for pulse width of 8 ns; o ±20 % for pulse width of 20 ns; o ±10 % for the rest of pulse widths.
7
• Limits of acceptable absolute error of measuring distances make up: ∆L = ± (dl + dL + L*∆n/n + 5*10-5*L), where
o dl = 0,3 m; o dL - resolution (sampling interval of backscatter signal), defined by
a prescribed range of the measured distance and the length of the measured span of OF m; dL can take the values 0.2, 0.4, 0.8, 1.6, 3.1, 6.5 and 13,1 m and is set by the operator;
o L – OF length, m; o n – OF refractive index; o ∆n – accuracy with which the refractive index is known for
measured OF. o The value of n can be set in the range from 1.00000 to 2.00000 with
step 0.00001.
• The values of dynamic range in dB for a signal-to-noise ratio SNR = 1, including number of averages = 16384 and a pulse width = 20 000 ns correspond to the table:
Wavelength 1310 nm Wavelength 1550 nm With filter 34 32
Without filter 32 30 Note:
The dynamic range may be decreased to 1.5 dB at maximum positive temperatures.
• Limits of permissible absolute error in measuring the attenuation is not more than ±(0,05 α), dB, where α is the measured attenuation, dB.
• Minimum resolution in measuring the attenuation makes up 0,001 dB.
• The value of deadzone in measuring the attenuation is not more than 10 m with the probe pulse width of 8 ns and a reflectance of not more than minus 40 dB (in the switched-on "High Definition" mode).
• The value of deadzone for detecting events is not more than 3 m with the probe pulse width of 8 ns and a reflectance of not more than minus 40 dB (in the switched-on "High Definition" mode).
8
• OTDR provides two main measurement modes: with and without averaging the measurement results. In the averaging mode set the number of averages or measurement time.
• Single-mode fibers are connected to the OTDR through optical FC connector. Installation of optical connectors of other types is possible.
• VFL (visual fault locator - the laser light source for visual detection of OF damage):
o Modes : OFF, ON, 1 Hz o Power : 1 mW o Wavelength : 650 ns o Connector : FC
• Connection with IBM-compatible PC through USB connector.
• Instrument control from a remote computer via TCP/IP is realized through an
Ethernet connector. • OTDR maintains its performance in the working conditions within 6 hours of
continuous operation in any mode of power supply.
• OTDR can be supplied from: o a built-in rechargeable battery; o an external power supply (12÷16) V o AC network with voltage (220 ± 22) V and frequency (50,0 ± 1) Hz
via AC adapter with output voltage 15V, belongs to the delivery set.
• Battery charge time – 4 hours.
• OTDR dimensions 220x125x45 mm.
• OTDR weight 1 kg.
9
Delivery Set
Designation Amount Note
Instrument 1
AC adapter, output voltage 15V 1 From network 220 V
USB interface cable 1 Connection with PC
Ethernet interface cable (direct) 1 Connection with LAN
Rechargeable battery 1 Inside of instrument
Optical single-mode connection cable with FC connectors 1
CD with software 1
User’s Guide 1
Safety Considerations Concerning protection against electric shock the OTDR corresponds to GOST
12.2.091, equipment class III. In the field of laser safety the OTDR corresponds to GOST 12.1.040 and Class 1M
of IEC 60825-1. OTDR can be handled by operator with qualifying group not lower than third, and
knowing the technical operation of a fiber-optical measuring instruments. To avoid the contact of pulsed laser radiation with eyes do not connect and
disconnect the optical fiber to the OTDR during measurements (when the laser is on). The laser safety label is applied on the OTDR panel.
Instrument Design The instrument is made in the housing with LCD touch screen color display having a
resolution of 640x480 pixels.
10
Appearance of the front panel is shown in the following figure:
Fig. 1. Instrument appearance
Control Keys on the front panel:
Instrument On/Off key
Confirmation key
Calling main menu of the instrument
Battery charge indicator
Instrument On/Off
Touch screen
11
Appearance of the connector panel is shown on the following figure:
Fig. 2. Appearance of the OTDR connector panel
USB port for data
exchange with PC
OTDR connector
650 ns visualizer connector (option)
External power supply connector
Ethernet connector for instrument control via
TCP/IP, pinging and IPTV-testing
Symbol «Caution! Laser
radiation!»
USB port for connecting
external devices
12
PRINCIPLE OF OTDR OPERATION Principle of OTDR operation is based on measuring the return signal of Rayleigh
scattering during the passage of a powerful single optical probe pulse through optical fiber. Weak backscatter signal recorded by a sensitive optical receiver, is digitized and repeatedly averaged.
The OTDR operates as follows. In accordance with the commands of the control program, the processor generates code to run the optical pulses. When the pulse passes through an optical fiber, part of its energy dissipates and goes back to an optical receiver, where it is converted into electrical form and amplified. Backscatter signal delay at the output of the optical receiver is equal to double-time passage of light through the optical fiber. The backscatter signal passes the matching amplifier and arrives at the input of the ADC and is converted into digital form. The ADC is synchronized by the processor.
Time reading started at the time t regarding the launch of the optical pulse corresponds to the signals scattered from the point of the optical fiber, being at a distance
2C tX n
×=
where: C is velocity of light in free space, n is core index of refraction of the optical
fiber. In one launch of the optical pulse the signals are measured, which came from a large
number of points of an optical fiber. To accurately measure the backscatter signal the optical pulse is launched many
times. In this case, the processor averages the readings corresponding to the same point of optical fiber, which increases the signal-to-noise ratio. After several such cycles, the values obtained for the signal are processed and displayed on the screen.
Thus the whole trace of the optical fiber is measured, stored and displayed. To increase the accuracy and dynamic range of measurements an operator who
works with the OTDR, can increase the number of averages. Herewith the time of measurement increases proportionally.
13
GETTING STARTED AND SWITCHING ON THE INSTRUMENT • Before you begin, make sure there are no mechanical damages to the instrument
housing. If the instrument was stored or transported at temperatures below 0 °C, it must be kept under normal conditions for 2 hours.
• Measured optical fiber is attached to the OTDR via optical connector on the front panel.
.
• To switch on the instrument press the key on the front panel. To switch it off
press this key repeatedly.
o Short pressing of the button switches over the instrument into
suspend mode. Exit from the suspend mode occurs almost
instantaneously and is fulfilled by the same button.
o Long pressing of the button switches off the instrument
completely. Restart from this state takes about 20 seconds. In the suspend mode the instrument consumes few milliamperes. It is recommended
once a week (e.g. on weekends) to completely disable the instrument and promptly to charge the battery. It is also highly reasonable to completely disable the instrument before its long-term storage or transportation.
14
The instrument can be also turned off with the [F] button on the touch screen:
Fig. 3. Instrument shutdown via the touch screen
15
Power Supply of the Instrument The instrument is powered by a rechargeable LiIon battery. The battery compartment can be accessed from the side opposite to the connector
panel.
Fig. 4. Battery compartment of the instrument
When the AC adapter is connected a fast battery charging takes place. Full-charge time does not exceed 4 hours. Charging process is indicated by a LED on the front panel of the instrument.
The residual charge is monitored by the battery icon on the screen.
16
MAIN MENU OF THE INSTRUMENT The main instrument menu appears when the device is switched on and can be
invoked from the operating mode with the button or via the drop-down list when you
press the touch button [F].
Fig. 5. Main menu of the instrument
The menu contains the following menu items:
• OTDR – reflectometer • Auto-measurement – OTDR with automatic measurement • "Test Station" – quick testing of the line compliance with template • Ping – communication inspection (pinging) of the remote hosts via the hosts
Ethernet, IPTV-test • Settings • PC connection - communication with PC
Select the desired menu item by pressing the appropriate icon or press the "OK" if
the desired mode is the current mode in menu (in the figure above the current mode is «OTDR»).
Current time Battery status display
[F] key
17
HOW TO WORK WITH TOUCH SCREEN Most of the operations with the instrument are realized via the touch screen. To this
end, the stylus can be pressed on the control buttons, the cursors can be moved, lists can be scrolled and so forth. As a stylus, you can use wooden or plastic sticks. It is not allowed to work with a touch screen using metal and other hard scratching objects.
In the following the screen operation examples are given.
Application Selection To select an application, press the stylus on the appropriate icon.
Fig. 6. Working with touch screen
18
Button Pressing Applications can be controlled by pressing buttons:
Fig. 7. Applications control
19
How to Select from the List To select an element from the list press the element.
Fig. 8. List manipulation
If the list does not fit on the screen, a scroll bar appears. To turn a page, press the stylus on it and, holding it pressed, scroll. You can also take advantage of pressing the scroll arrows.
20
[F] Button In all applications [F] button is in the upper right corner of the screen. When pressed,
the drop-down list of commands appears:
Fig. 9. [F] button
• OK Duplication of [OK] hard key
• Menu Duplication of [Menu] hard key
• Help Displaying of the context-sensitive help display
• Full screen Full-screen mode ON/OFF
• Suspend Changeover of the instrument to suspend mode. In the suspend
mode, the instrument may stay within some weeks.
• Turn off Complete instrument disabling for long-term storage
21
OPTICAL REFLECTOMETER (OTDR) To enter the OTDR mode select OTDR item in the main menu.
How to Connect the Optical Fiber Connect the OTDR to the test fiber through a FC-type connector on the front panel.
Fig. 10. Connecting of the optical fiber
ATTENTION! To avoid the contact of pulsed laser radiation with eyes do not connect and disconnect the optical fiber to the OTDR during measurements (when the laser is on).
ATTENTION! Never connect the cables to the OTDR, if you are not sure of the
purity of optical connectors. This can cause damage to the OTDR connector or lead to wrong results.
OTDR connector
22
Main Screen In the main screen traces can be viewed and all kinds of measurements can be carried
out. The main screen is shown in the following figure:
Fig. 11. OTDR main screen
The screen contains the following elements: • Upper field - trace name. • Functional buttons. • Operating control buttons • Working area, in which the window with trace is placed. • Information field under the working area, which appears, if measurements are carried
out or the trace window is opened. • Cursors to perform measurements. Active cursor is marked by arrows and can be
moved. To select the cursor press [OK].
Trace name Battery status F button
Functional buttons OPE Information field
Working area
23
Buttons for calling special functions
[Storage] - Working with the instrument memory. Record the current trace, loading a previously recorded trace for comparison.
[Parameters] - Setting the measurement and analysis parameters.
[Start/Stop] - Start/Stop measuring trace.
[Analysis] - Run the trace analysis.
Operating control buttons
[Action]
- Drop-down list of actions with the working area
o Cursors
o Zoom
o Scrolling
o 1:1
[Show cursors] - Placing the cursors within the current screen
[Range] - Set the measuring range - the maximum length of the measured distances.
[Pulse] - Set the duration of the probe pulse.
[Screen] - Switch "trace" – "comparison". Active, if the trace is pre-
loaded for comparison from the instrument memory. More details see in "Working with memory".
[Mode] - Measure mode switch. More details see in "Running measurements".
[Events] - Enable/disable displaying of events identified during the
analysis of traces. When you enable the events the screen varies slightly.
[Map] - Enable/disable displaying of trace map.
Switches change their value by pressing the appropriate buttons on the instrument
front panel. "Actions", "Range" and "Pulse" change as follows:
• single touch – entrance into the value change mode, • select the desired value from the dropdown list.
24
Information field Field values of the information panel, which appears if running measurements, or
opening a window with trace, depend on the measurement mode, can be changed by pressing the [Mode] button.
Full-screen mode The mode is enabled/disabled through the [F] button and allows stretching the
working area over the entire screen.
Fig. 12. Full-screen mode.
25
Starting the Measurement Process Acquisition of trace is possible without averaging and with averaging. In the first case the picture on the screen is constantly updated. In the second case, the process must be run each time with the [Start] button. At the start of trace acquisition procedures the instrument analyzes the presence of
optical power in fiber. If the fiber is live, then the instrument displays a message:
Fig. 13. Live fiber
and blocks measuring. Acquisition of trace is possible only on dark fiber. In this case, connect to the dark fiber, then press [OK] and restart the measurement.
26
Starting the measurement process without data averaging To start measurement press the [Start] button, provided that the option "Number of
averages" in the settings is set to "OFF". To stop the measurement process the [Stop] button can be used. In the measuring mode without averaging (fast measurement) a trace is displayed on
the screen at regular time intervals, while the picture is completely updated, averaging is not performed. This mode is primarily used when a quick preliminary assessment of the line state is needed, the alignment of the two optical fibers before they are welded, or in other similar cases.
Starting the measurement process with data averaging To start this measurement process press the [Start] button, provided that the option
"Number of averages" (or "Averaging Time (minutes)") in the settings is set. Measurement mode with averaging is designed to measure optical fiber with
subsequent investigation of its parameters. The results of the measurements are averaged. On the screen in the bottom line of the main window an indicator is displayed, which displays the relative time scale of measurement. The end of the measurement process corresponds to complete filling of the time indicator scale. Upon completion of the measurement a beep will be heard.
The measurement process with averaging can be aborted by pressing the [Stop] button. In this case, it is not recommended to use the acquired trace to determine the characteristics of OF.
27
Trace Manipulation
Cursors manipulation All measurements are carried out on a trace using cursors. Cursors can be from one
to five, but in any case, only one cursor can be active. The active cursor is marked by arrows at the ends and can be moved. To do this, set the [Action] button and select "Cursors" and then the cursor can be caught with the stylus (press and release the pressure) and moved.
Fig. 14 Cursors manipulation
Active cursor Inactive cursor
28
For more precise positioning of the cursors you can press the stylus anywhere on the working area. If you press on the screen more to the right of the active cursor, then the cursor will move to the right, and vice versa. Short pressing shifts the marker at the lowest possible step with the current zoom. Long press will accelerate the shift, which is useful for quickly changing the position of the cursor.
Fig. 15. Exact marker positioning
Press
29
To select the active cursor press the stylus on the working area next to the required cursor or
Fig. 16. Selecting active cursor
press [OK]. The second option is especially useful when zooming, when all the cursors are not in the visible region.
Fig. 17. Changing active cursor by pressing [OK] button
Press and this cursor became active
30
Zoom For more accurate cursor positioning and observation of the trace span of interest,
the [Zoom] button can be used.
• Press [Action] and select "Zoom". • With the stylus mark a rectangular area of the trace span of interest.
Fig. 18. Trace zooming
31
Release the stylus. The marked area will be displayed on the screen.
Fig. 19. Viewing trace span with zooming in
When zooming cursors probably will not get into the viewing area. When the button [Show cursors] is pressed they will automatically be moved from its previous state and will be placed in the visible region.
To return to view of the entire trace press [Action] and select "1:1".
32
Scrolling When the zoom is used to move over the trace it is convenient to use scrolling. To do
this:
• Press [Action] and select "Scrolling".
• Press on any part of the workspace, and not interrupting pressing move the viewing
area in any desired direction.
Fig. 20. Scrolling
In the scrolling mode, the stylus will move trace, not markers. To recover control of
the markers press [Action] and select "Cursors".
33
Map If the zoom is used it is not always clear which part of the trace is displayed in the
working area. To solve this problem the [Map] button can be used. When pressed, the cable map appears with a marked area.
It is convenient to navigate over the map by pressing the stylus on the interesting part of the trace.
Fig. 21. Using the cable map
Cable map Area under observation
34
Distance measurement Distance measurement is performed using two cursors – left and right. One of the
cursors is marked by arrows and is active. To measure the distance between two events set the appropriate cursors at the
beginning of events. For more precise positioning the zoom function should be used. When using the zoom function only a part of the total cable trace is displayed. To
understand which part is currently displayed, helps the enabling of the map using the [Map] button.
The accuracy of determining the distance on basis of trace depends, inter alia, on the correct installation of the refractive index of optic fiber.
The distance itself is displayed on the information panel – in the (R-L) field:
Fig. 22. Distance measurement
On this example, the left cursor is outside of the screen. Pressing the [OK], the left marker can be selected and part of the traces around it will be displayed. To switch back – press again [OK].
Absolute cursor location relative to instrument connector
35
Smart marker (marker) When processing the acquired trace it is very convenient to use semi-automatic
measurement of the event parameters. • Acquire the trace of optic fiber.
Fig. 23. Smart marker. Trace acquisition.
• Set the "marker" mode.
36
• Using zoom display part of the trace.
Fig. 24. Smart marker. Zooming
Fig. 25. Smart marker. Displaying trace span
37
• Press [Action] and select scrolling.
• Moving along the trace, visually locate the event.
Fig. 26. Smart marker. Scrolling
• Press [Show cursors]. In the working area will appear the only cursor - the smart marker. The instrument will change over from scrolling to work with this marker.
38
• Set the marker at the beginning of the event as accurately as possible.
Fig. 27. Smart marker. Marker positioning
• Press [OK]. • The device will analyze the event and enter its parameters into the event table.
Fig. 28. Smart marker. Result of event processing
39
For the analysis of the following event switch once again to the scrolling and repeat the operations.
To view all events press [Events] and select "ON" or "Table".
Fig. 29. Smart marker. Viewing.
Fig. 30. Smart marker. Viewing - table.
40
Smart marker analyzes the event by five cursors method. Before adding an event, you can see how cursors are placed and if necessary, move them by selecting the mode «LSA losses". More details about the mode «LSA losses" can be found in the section "Attenuation measurement in OF connections (LSA-losses)".
41
2-point attenuation measurement in OF (2P losses) To measure the attenuation by two points set "2P losses" when pressing the [Mode]
button. To measure the attenuation in a span of the optic fiber and its length set the cursors at
the ends of this span and read its data in the line of the information panel:
Fig. 31. 2-point attenuation measurement
If the cursors are outside of the screen, you can bring them into the working area using the [Show cursors] button.
To measure the attenuation of the entire optical fiber set left cursor outside the dead zone.
Span length R-L, km.
Attenuation coefficient value in dB/km
Attenuation between points where cursors cross the reflectogram in dB
42
Long attenuation measurement (LSA-line) To measure the long attenuation by two points set "LSA line" pressing the [Mode]
button. In contrast to the mode of "2P losses" here a straight line approximation of the trace span between the cursors is performed using the least squares method. The so calculated value of the long attenuation is more correct, provided that the cursors are on a homogeneous part of the line.
To measure the attenuation in a span of the optic fiber and its length set the markers at the ends of this span and read its data in the line of the information panel:
Fig. 32. Measuring long attenuation of the fiber span with straight line approximation
To measure the attenuation the cursors should be set within the homogeneous part outside the dead zone.
If the cursors are outside of the screen, you can bring them into the working area using the [Show cursors] button.
Span length R-L, km.
Attenuation coefficient value in dB/km
Attenuation between points where cursors cross the reflectogram in dB
Approximating line
43
Attenuation measurement in OF connections (LSA-losses) The instrument allows to estimate the attenuation in the optical fiber connection by
five cursors method. By pressing the [Mode] button set "LSA losses". Place the cursors near the connection so that it is between them. In this case, sections of some length, which are to the left of the left cursor and to the
right of the right cursor, can be straight line approximated, and the attenuation in the connection is calculated. The connection point is marked with the central marker, and the span of approximation – with heavy lines. All five of the cursors can be moved independently of each other. Switching between cursors with the [OK] button.
Approximation spans should, wherever possible, have a maximum length and be uniform. Central cursor should be set at the left edge of the connection (at the beginning of the event).
Fig. 33. Measuring attenuation in the fiber connection
Span length between markers R-L, km.
Distance from the fiber start to the connection (to the central cursor - bar)
Attenuation in the connection in dB
44
Reflectance measurement (reflection) The device can determine the reflectance from the plug connection of the two optical
fibers or from the end of the OF. • When pressing the [Mode] button set "Reflectance". • Set the right cursor on the top of the reflected pulse, the left cursor – on
the traces span directly in front of it:
Fig. 34. Measuring the reflectance.
If the cursors are outside of the screen, you can bring them into the working area using the [Show cursors] button.
The span length between the markers R-L, km
Distance from the fiber start to the left cursor Reflectance in dB
45
Optical return loss measurement (ORL) The device allows to estimate the value of Optical Return Loss (ORL) of the fiber
line span or of the entire fiber line. ORL is the ratio of power supplied into the optic fiber, to the power coming back to the fiber start from the specified fiber line span or of the entire fiber line.
• By pressing the [Mode] button set "ORL". • Position the cursors at the ends of the measured span.
Fig. 35. Optical return loss measurement (ORL).
The span length between the cursorsR-L, km
ORL value in dB
Difference between signal levels at points labeled by markers in dB
46
Parameter Settings Before starting the measurement it is recommended to set its parameters. To do this,
press the [Parameters] button. The screen is shown on the picture below:
Fig. 36. Changing measure parameters
Return to measuring mode – with the [Trace] button. The [Factory settings...] button allows to restore the parameters set during
manufacturing of the instrument.
47
Measure parameters
Fiber type (wavelength)
- 1550 (single-mode fiber, wavelength 1550 nm).
- 1310 (single-mode fiber, wavelength 1310 nm).
- 1310+1550 – acquisition of two traces at once at different wavelengths with the obligatory auto save of results.
Resolution (m) - The distance between the two readings of OTDR (sampling interval).
Number of averages
- The total number of trace averages is specified in the mode with averaging.
OFF, number of averages
Averaging time (minutes) - OFF, time
Averaging in time - Time averaging is enabled. If it is disabled – the averaging according to measurement number.
Refractive index of OF (n) - The value of the refractive index of OF; changes in
increments of 0.00001, in the software supplied to the user, is set to 1.46810.
Reduced laser power - The trace measurement mode with a reduced capacity of
the laser radiation is enabled. This mode is reasonable for measuring high reflectivity values from the heterogeneities.
High resolution
- In this mode, the bandwidth of the optical receiver is increased what allows to reduce the deadzone and better to distinguish between the close lying heterogeneities. However, in this mode the noise of the optical receiver increases.
Filter - The digital filtering of acquired trace is enabled/disabled.
48
Analysis parameters Threshold values are specified for the automatic trace analysis.
Fig. 37. Changing automatic analysis parameters
Return to measuring mode – with the [Trace] button. The [Factory settings...] button allows to restore the parameters set during
manufacturing of the instrument.
49
Loss threshold (LT)
- Loss threshold in heterogeneities, dB
Heterogeneities, in which the attenuation exceeds a given threshold, are displayed in the table of landmarks during trace analysis.
In the software supplied to the user, this value is set to 0.2 dB.
Reflectance threshold (RT)
- Reflectance threshold value, dB.
Heterogeneities with reflectance above this threshold are displayed in the table of landmarks during analysis.
In the software supplied to the user, this value is set to 60 dB.
End-of-fiber threshold (ET)
- Attenuation threshold value, dB, to determine end of fiber.
The first heterogeneity with attenuation greater than a threshold value ET, is determined during trace analysis as the end of OF, all subsequent heterogeneity are ignored.
In the software supplied to the user, this value is set to 3 dB.
Loss coefficient threshold (CT)
- Threshold value for the attenuation coefficient of the span, dB/km; if the loss coefficient threshold is exceeded it is noted with an asterisk in the table of landmarks .
In the software supplied to the user, this value is set to 0,4 dB/km.
Backscatter coefficient (ВС)
- Part of the power of an optical pulse in dB dissipated in the OF and extending to its beginning. In the software supplied to the user, the following values are set :
• minus 81 dB for single-mode fiber and wavelength 1550 nm;• minus 80 dB for single-mode fiber and wavelength 1310 nm.
The backscattering coefficient can be set in increments of 0.1 dB.
Miscellaneous
Auto search RFG
- Enables/disables the trace search mode when the cursor moves. Is set at a zoom greater than 1.
- Recommended value – ON.
50
Automatic Analysis The instrument allows to automatically analyze the measured trace, or trace loaded
from the instrument memory. Starting – with the [Analysis] button. The automatic analysis process can take a long time, depending on the length of the
analyzed fibers, the number of defects and thresholds. The device searches for irregularities, the attenuation or reflectance of which exceed
set thresholds. Thresholds are defined in the parameters. In the analysis the distance to the events, the attenuation coefficient of the spans
between the events are determined. These data are stored in the table of landmarks and displayed as icons and landmarks on the trace, if the [Events] selector has the state "ON" or "Table".
It should be borne in mind that in a long line when the far end spans of the trace are distorted with noises, and their automatic analysis may be inaccurate, for example, welded joints of OF with low attenuation can not be recognized on the noise background. These spans should be analyzed "manually" by moving the marks, erasing the incorrect and placing new ones.
Threshold values, at which the automatic trace analysis was held, are stored when the file with the trace is saved.
If the trace already contains event mark, so when the automatic trace analysis is started these marks are erased.
51
Landmarks on the trace Analyze trace and by pressing the [Events] button select "ON" item. The event landmarks and the numerical values of the parameters analyzed will
appear on the screen. Type of events:
• reflective events, when the reflection is above the threshold value, regardless of the attenuation in the event,
• and non-reflective events, when the attenuation is greater and the reflection is less than the corresponding threshold values,
• end of the fiber. Parameter plotted on the trace:
• The distance to the event in kilometers (vertical caption below the landmark without dimensionality).
• The attenuation coefficient of the span between the events (horizontal inscription over the span, dB/km). The screen is shown in the following figure:
Fig. 38. Trace appearance after carried out automatic analysis
52
Event Table It is possible to list all events in the trace. To do this, press [Events] and set the
"Table", on the screen a window will appear with a list of events corresponding to inhomogeneities in the measured lines, ordered by distance from the line beginning. In the following example the heterogeneity number 1 corresponds to the start of fiber.
Fig. 39. The Event Table and additional control buttons
The table contains: • Type of events:
o reflective events, when the reflection is above the threshold value, regardless of the attenuation in the event,
o and non-reflective events, when the attenuation is greater and the reflection is less than the corresponding threshold values,
o end of the cable. • Serial number of the event. • Distance from the start of the fiber to the current event, km. • Attenuation in the event if it exceeds the threshold value, dB. • Reflectance in the event (if it exceeds the threshold value), dB. • Attenuation coefficient of the span between this event and previous one, dB/km. • Total attenuation from the start of fiber to the current event, dB.
53
The choice of event in the landmark table is made by pressing. Selected event is highlighted with color in the landmark table and with red outline around the landmark in the bottom of the trace window.
Operator's work with markings When working with trace operator can delete and move landmarks, working with a
landmark table, as well as create new landmarks. By pressing the [Delete event] button the landmark is deleted from the landmark
table and from trace. To create new landmarks select the appropriate measurement mode with the [Mode]
button, set markers, and having received the measurement result in the table of the information panel, pres [Add event] button. The landmark will be recorded and settled on the trace and simultaneously entered into the landmark table: • when measuring the attenuation in the OF connection the position of the central
marker is fixed on the trace, the parameters of the marked event are recorded in the landmark table, while the program automatically calculates the reflectance of the event and it is entered into the landmark table, if it exceeds the threshold value;
• when measuring the reflectance the position of the left marker is fixed on the trace, the parameters of the marked event are recorded in the landmark table, while the program automatically calculates attenuation in the event, which is recorded in the landmark table. When pressing the [Move event] button for selected heterogeneity in the window
with trace the position of the markers is reproduced, for which the parameters of this heterogeneity are estimated. Using the stylus the mark corresponding to this heterogeneity (central marker) can be moved, the position of other markers can be changed, which allows to adjust the heterogeneity parameters, obtained by automatic or manual trace analysis.
Landmarks moved and created by the operator are removed at the subsequent start of
the automatic trace analysis.
54
How to Work with Memory This mode is intended to save the current trace and load a previously saved trace for
comparison. It is possible to load two saved traces for comparison. Input with the [Storage] button.
Here also a template can be created for further work with the ""Test Station"" application.
The screen after mode entrance:
Fig. 40. Working with memory
To enter the folder: select it and press [OK].
Folders with traces– indicated by italics and by color
Traces
Viewport
Trace parameters
55
To exit the folder, select the top line and press [OK]:
Fig. 41. Working with folders
Purpose of functional buttons
[Trace] - Return to main screen.
[Delete all] - Removing all traces from the instrument memory.
[Move] - Moving the specified trace in the folder.
[Change name] - Changing the name of the selected trace.
[Create folder] - Creating the folder for traces.
[Delete folder] - Deleting folder for traces.
[Delete RFG] - Deleting the selected trace.
[Save RFG] - Saving the current trace
[Create template] - Creating the line template for working with the ""Test Station"" application
56
How to load trace for viewing and comparing The device allows you to view a trace, or to compare two traces. When comparing
the main trace is shown on the screen in green, the second – in red. • Select the trace from the list.
In the upper right window the preview of the selected trace will be displayed. In the lower right window the parameters of the stored trace will be shown:
o Serial number of the instrument. o Serial number of the optical module. o Wavelength. o Refractive index. o Range. o Probing pulse width. o Number of averages.
• Press [OK] button. The instrument allows you to open files acquired with other types of OTDR and
saved in BELLCORE format (version 2.0). These files have the extension .sor.
57
How to create folder Traces can be stored in separate folders, which allow you to order the results of
measurements. A new folder is created by pressing the [Create Folder] button. After this the screen
appears to enter the folder name:
Fig. 42. Putting strings in the instrument.
Select the symbol by pressing. After completing the entering press [Apply changes] button. Subfolders can be created.
58
How to save current trace • If you work with folders enter the required folder. • Press [Save RFG] button. • Screen appears, allowing you to enter your trace name or to accept the name
proposed by the instrument. • Select the symbol by pressing. After completing the entering press [Apply changes]
button. The instrument offers a name in line with the name mask given in the "Settings"- "Application Properties":
Fig. 43. Application properties
RFG_1310nm_5km_00013.sor
59
For setup select "File name template" and press [OK]. The setup screen appears:
Fig. 44. Setting-up the file name template
User string should be edited and the checkmarks should be set as you wish. If the setup is made, as shown in the figure, the trace will be assigned successively names:
RFG_1310nm_5km_00013.sor RFG_1310nm_5km_00014.sor RFG_1310nm_5km_00015.sor Etc. The instrument saves traces in the BELLCORE (2.0) format, with the file extension
.sor; they can be analyzed on a personal computer with the standard software as well as with programs from other manufacturers.
60
How to move trace in the folder The traces can be moved in the desired folder. To do this, select the trace and click
[Move]. Enter the folder and pres [Apply].
How to work with external memory (USB flash) The instrument supports external USB flash storages. Insert the storage into the USB
connector:
Fig. 45. Connecting flash storage
61
The storage will appear in the list. It can be handled like a normal folder:
Fig. 46. Displaying the flash storage in the list
62
Mass Measurements of Traces During the acceptance measurements on cables containing many fibers the
acquisition of traces is required at the wavelengths of both 1310 nm and 1550 nm. To simplify the work a special mode is provided in the instrument.
Operating procedure • Connect one of the fibers to the instrument. • Set the necessary measure parameters. In the parameters set "type of OF
(wavelength)" = "1310+1550". • Be sure to select the desired number of averages or the averaging time,
except for "OFF".
Fig. 47. Setting of measurement at two wavelengths
63
• In the instrument memory create a folder with the name of your cable and enter it.
Fig. 48. Mass measurements. Creating a folder
Fig. 49. Mass measurements. New folder
64
• Measuring can be started. • Each time you press the [Start] button two traces will be acquired
immediately. By default, the traces will be named as follows: o reflectogram_1310_00000.sor o reflectogram_1550_00000.sor o reflectogram_1310_00001.sor o reflectogram_1550_00001.sor o reflectogram_1310_00002.sor o reflectogram_1550_00002.sor o Etc.
Fig. 50. Mass measurements. Result
• Increment in the name and auto-save will be installed automatically.
65
• If you do not like the file name "reflectogram" the template can be changed by yourself via the application "Settings".
Fig. 51. Mass measurements. File name template 1
Fig. 52. Mass measurements. File name template 2
66
How to Control the Fiber Welding Process When installing fiber-optic communication lines one is often faced with the task of
control of the welding process of the next span.
Operating procedure
• Connect the fiber to the instrument. • Set the necessary measure parameters. Select the range taking into account
the newly welded span. Set the measurement without averaging. • Start living measuring with the [Start] button. • Stop living measuring with the [Stop] button. • Using zoom display the end of the fiber in the working area of the screen. • Using mode «LSA loss" determine the loss at the end of the fiber. • With the [Start] button restart live measurements (measurements without
averaging). The instrument will constantly measure the losses at the end of the fiber tracking process of welding. This is the indicator mode.
• When on the screen will be seen that the new span is welded, it is necessary to carry out more correct measurements with a sufficient number of averages.
67
VISUAL FAULT LOCATION Function is only available for instruments equipped with special VFL module. To enter the visualizer mode select the OTDR item in the main menu. The visualizer
consists of a laser with a wavelength of 650 nm (red) with a nominal power of 1 mW.
How to Connect the Fiber Connect the OTDR to the test fiber through a FC-type connector on the instrument
front panel.
Fig. 53. Connecting the fiber to VFL.
ATTENTION! To avoid the contact of pulsed laser radiation with eyes do not connect and disconnect the optical fiber to the OTDR during measurements (when the laser is on).
ATTENTION! Never connect the cables to the OTDR, if you are not sure of the
purity of optical connectors. This can cause damage to the OTDR connector.
Visualizer connector
68
Laser Control The laser is controlled through the [Parameters] button of the OTDR application.
Fig. 54. 650 ns laser control is realized through parameters
69
Fig. 55. 650 ns laser control
• Select "650 ns laser" from the list/ • Press [OK]. Window of values will be opened:
o OFF (laser is disabled) o ON (laser is permanently enabled) o 1 Hz (laser flashes at the frequency of 1 Hz)
• Select required value and press [OK]. Return to the OTDR mode with the [Trace] button.
70
AUTOMATIC MEASUREMENT Selecting item "Auto-measurement" in the main menu allows even the untrained
meter to quickly view the optical line. The main screen is fully consistent with the "OTDR" screen, but most of the items are inactive.
When working with this application take into account that the instrument selects the coarsest resolution, and the pulse width is selected in accordance with the table:
Fiber length [km] Pulse width [ns]
0 ÷ 0,3 8 0,3 ÷ 0,5 16 0,5 ÷ 1 64 1 ÷ 1,5 128
1,5 ÷ 2,5 256 2,5 ÷ 4 512 4 ÷ 7 1 000 7 ÷ 10 3 000 10 ÷ 25 5 000 25 ÷ 35 7 500 35 ÷ 45 10 000
> 45 20 000
71
How to Connect the Fiber Connect the OTDR to the test fiber through a FC-type connector on the front panel.
Fig. 56. Connecting optical fiber to the OTDR
ATTENTION! To avoid the contact of pulsed laser radiation with eyes do not connect and disconnect the optical fiber to the OTDR during measurements (when the laser is on).
ATTENTION! Never connect the cables to the OTDR, if you are not sure of the
purity of optical connectors. This can cause damage to the OTDR connector or lead to wrong results.
OTDR connector
72
Running Measurements After entering the application "Auto-measurement" the following screen appears:
Fig. 57. Start screen "Auto-measurement"
73
Pressing the [Start] button starts the measurement process. At the beginning of trace acquisition procedure the instrument analyzes the presence
of optical power in fiber. If the fiber is live, then the instrument displays a message:
Fig. 58. Live fiber
and blocks measuring. Acquisition of trace is possible only on dark fiber.
74
In this case, connect to the dark fiber, then press [OK] and restart the measurement.
Fig. 59. Starting measuring process
Start/Stop button
75
After measurement completion, the automatic trace analysis will be performed and the results will be shown on the screen:
Fig. 60. Viewing auto-measurement results
The screen will show the event landmarks and the numerical values of the parameters analyzed.
Type of events:
• reflective events, when the reflection is above the threshold value, regardless of the attenuation in the event.
• and non-reflective events, when the attenuation is greater and the reflection is less than the corresponding threshold values,
• end of the fiber. Parameter plotted on the trace:
• The distance to the event in kilometers (vertical caption below the landmark without dimensionality).
• The attenuation coefficient of the span between the events (horizontal inscription over the span, dB/km). To repeat the cycle the [Start] button ca be pressed again.
76
During automatic measurements the instrument determines the optimum measurement range by itself. In some cases there may be problems with the definition of the end of the cable. In this case, the desired range can be set by hand.
Fig. 61. Manual range selecting
77
TEST STATION The ""Test Station"" function allows you to quickly test the optical line. For this
purpose it is enough to connect OTDR to the line and to select the required template from the memory. The instrument will repeat the measurements, compare the result with the template and give a conclusion about the serviceability of the line. In case of failure the instrument will determine the cause and localize damage. In addition, using the ""Test Station"" function the routine monitoring of the lines can be carried out.
Checking Line for Compliance with Template After entering the ""Test Station"" application a list of cables (trace-templates)
appears on the screen, which are in the instrument memory. Select the desired entry, e.g. <STATION 1 LINE 8> and press "OK ".
Fig. 62. Selecting template in the instrument memory
The instrument starts the process of cable measurement and comparison with template. The results are displayed on the screen.
78
3 main options are possible:
1. The line is operable. The instrument informs: "The measured trace corresponds to the template". Indeed, the template (red line) and the measured trace (green line) coincide on the screen.
Fig. 63. Result 1: the measured trace corresponds to the template
79
2. Fiber break in the line. The instrument informs that the line is broken at a certain distance. The figure shows the case where the distance to the break is 657 m. As result of the damage unacceptable events appeared - a reflection and a large signal attenuation. The line is broken.
Fig. 64. Result 2: Fiber break
80
3. The measured trace has unacceptable deviations from the template. In this case, on the bases of the event table places of unacceptable deviations can be located.
Fig. 65. View deviations from the template in the event table
The operator can visually detect the line defect comparing traces or use the event
table.
In this simple way any member of the station can test the line. But first the meter man should input the template in the instrument memory.
81
Creating Templates The template is created by a professional meter. It establishes the necessary settings
for measurement and acquires a trace. After the measurement it is necessary to perform manual or automatic analysis and make sure that the results of measurements are suitable to create a template.
Fig. 66. Preparation of the template
Now the template is to be created. To do this, • Press [Storage] button. • Create a folder for this line. Each folder can contain only one template. • Enter the folder. • Press [Create template] button.
Assigning the required file name, the extent should be indicated to which the deviation of the line parameters is acceptable. The meter man specifies, which limit deviations are possible for this line regarding attenuation, reflection, attenuation coefficient and total losses of signal in the line.
82
Fig. 67. Setting (changing) template parameter
Template is ready. Templates can be stored in the instrument or on the computer and installed on any instrument. Thus, instruments with a ""Test Station"" are ready for repeated measurements. If repeated measurements fall within the specified tolerances, the instrument reports that the line is operable. If the tolerances are violated, the instrument detects the failure cause and isolates damage.
Creating a Template from Previous Measurements As a template, the record of measurements made by any OTDR can be used. The
main thing is the trace has been saved in a universal format SOR (Bellcore GR-196/SR-4731). Program "OTDR View" from delivery set will create a template for "Test Station" on the basis of an usual trace.
Line Damage and Line Monitoring In the simplest case, you cannot set the tolerance limits for repeated measurements.
We are talking about the localization of one of the most frequent injuries –line break. If tolerances are not specified, the "Test Station" determines only the line break, without focusing on the analysis of the parameters of other events.
To localize the break a single parameter of the automatic analysis is used: ET - end of fiber threshold (the threshold of the end of the cable). In other words, Fiber Break Locator function works. In this case the advantage of the "Test Station" in comparison with the normal locator function is only that due to a template, the locator is configured to the parameters of the damaged cable - the appropriate measurement range is selected. In this way, malfunctions of the locator are eliminated.
However, there may be cases where the line fault does not occur as a result of mechanical damage, but as a result of gradual degradation of one of the elements of the
83
line. For example, one of the compounds has hidden defect, which develops under external influence. The quality of welded joints can be affected by environmental conditions such as temperature, humidity, and barometric pressure, wind. As a result of deterioration in the quality of welded joint additional losses arise that may lead to malfunction of equipment.
Fig. 68. Result 3: measured trace contains unacceptable deviation
Function "Test Station" allows you to monitor the line, without resorting to complex and costly measures. Degradation of the line - it's a slow process. Changes can be tracked by test measurements at regular intervals, say 6 months. For test measurements using the "Test Station" function the line must be disconnected just for a few minutes. The instrument has already the required settings for the test line, where all necessary tolerances are set for comparison with the template. If unacceptable changes in the welded joint or in an optical fiber occurred, the function "Test Station" will report an emergency. Further decisions are made by a professional meter based on trace analysis.
84
Saving Results A trace acquired in the application can be stored in the instrument memory. To save you need to:
• Press the [Storage] button. • Press [Save RFG]. • Save the trace under the proposed name.
The trace will be automatically saved in the folder with previously selected template. The record name shows the date and time of measurement. Such records can be many.
85
PING Function is used to:
• Check communication with remote computers via TCP/IP in Ethernet networks. Ping may be useful for problems in networks where the fiber itself does not reach the subscriber and the communication in the last span is carried over Ethernet. The instrument sends a request to a specific IP address and records the incoming responses.
• Check the IPTV-signal transmitted through Ethernet.
Connection to Line Connect the instrument to an Ethernet line.
Fig. 69. Ethernet connector
86
Pinging After entering the application «Ping» the following screen well appear:
Fig. 70. Start screen Ping.
87
Before beginning of the operation parameters should be set.
Fig. 71. Ping parameter setup
Local address IP address of the instrument itself Remote address IP address of the remote computer Packets count Number of sent requests (packets) Wait interval (seconds) Wait interval between packet sendings Packet size (bytes) Packet size ttl The maximum number of IP-routers through which the
packet will still be delivered, and not be considered as lost
Pattern (HEX) Pattern for packet filling. May be not filled Most importantly is to set the desired "Remote Address". When you enter the
application the instrument sets the remote address, which is the same as that of the instrument itself. Thus, if we do not change the instrument will ping itself.
To access a remote computer, a valid address must be entered.
88
After setting the parameters ping can be carried out. The result will be displayed on the screen:
Fig. 72. Ping result.
Packet size
Remote IP address
Request number
Delay time
Total statistics for all packets
89
IPTV Test Before beginning of the operation parameter should be set.
Fig. 73. IPTV-parameters setup
URL IP address and port (through colon) of IPTV Local file Selecting local file from the instrument memory or
from flash storages (.avi etc.) Recent URLs List of recent tested URLs. Number of frames Number of video frames captured by the instrument.
Can be set from 1 to infinity. If you set the frame number n, the instrument will show them and stop at the last, showing the test results. It is recommended to set n = 1.
Sound Turning on and off the audio channel test. If enabled, the instrument will show the parameters of audio codec.
Frame/s (fps) The frequency of the frames output on the instrument screen.
Video codec family Selecting video codec family
90
After configuring the settings, IPTV can be inspect, pressing the [IPTV] button. The result will be displayed on the screen:
Fig. 74. IPTV test result
Codec Resolution Frames per second
Flow rate
VIDEO
AUDIO
Numb. of channels
Sampling frequency Flow rate
91
SETTINGS Selecting "Settings" in the instrument main menu allows you to access the general
parameters of the device, such as:
• Date/time
Fig. 75. Setting date and time
• Language
Fig. 76. Selecting language
After you change the language the instrument will restart the main menu with the new settings.
92
• Display
Fig. 77. Setting display options
• Power
Fig. 78. Instrument power control.
93
• Applications properties Parameters are defined in the relevant sections of this description.
Fig. 79. Changing applications parameters
Exit from the settings in the main menu with the button.
94
DATA EXCHANGE AND REMOTE CONTROL When entering the application "PC connection" the following screen appears for
selection:
Fig. 80. PC connection
Item "USB file storage" is used to exchange information between the instrument and the computer.
"Remote control via TCP/IP" - instrument control from a computer. «File manager» - working with files and with external flash storage.
Data Exchange with PC Select "USB file storage" and press [OK]. Then connect the instrument to the PC via
USB cable. Further, the instrument is defined as a disk on your PC. Data exchange can be done using Windows Explorer or similar software.
Fig. 81. Mini USB connector for connecting the instrument to the PC
95
Remote Control via TCP/IP This function is intended to work remotely with the instrument using the program
"OTDR View". In the application "Settings", select item "Applications properties", set the IP address
of the instrument in accordance with the mask on your network.
Fig. 82. Changing IP address of the instrument
Connect the instrument and the PC with Ethernet cable. The delivery set contains a "direct" cable, which can be used when connecting through a switch or directly, if your computer has a port 1G Ethernet. For 10/100 Mbps a "cross" Ethernet cable is require.
Turn on the instrument and run the "OTDR View" program on your computer. To work use the tips of the program.
96
File Manager This function is intended:
• To delete files from the instrument memory. • To copy files in the folders of the instrument memory. • To create folders. • To rename folders and files. • To exchange files between the instrument memory and external flash
storage. In the application "PC connection" select "File manager"
Fig. 83. Selecting function "File manager"
Press [OK] button.
97
If an external flash storage is connected, then the screen view will be roughly as follows:
Fig. 84. "File manager" screen
External flash storage
Internal instru-ment memory
Contents Icon for object selection
Control buttons
98
All operations on objects (files or folders) start with their selection.
Fig. 85. File manager – selecting objects
Then you can remove items or copy them to a new location. To copy, press the [Copy] button and it will change to the [Paste] button.
Fig. 86. File manager – copying
99
Next you must choose a location to copy. For example, you have to copy the selected files in the folder "FROM INSTRUMENT", located in the external flash storage.
Fig. 87. File manager – selecting objects
And press the [Paste] button.
Fig. 88. File manager – pasting.
100
MAINTENANCE Maintenance includes control inspection, during which are verified:
• completeness of the OTDR according to section "Delivery set"; • absence of mechanical damage to the housing, front panel, connection elements.
Identified defects must be eliminated. Optical connector of the OTDR should be regularly cleaned of contamination. To do
this, make dense wick of cloth, intended for use with optical connectors, for example, Kimwipes, so that its thickness is slightly less than the inner diameter of the optical connector, moisten it with pure alcohol (isopropyl or ethyl alcohol) and carefully and gently wipe the connector inside the bush. After wiping let alcohol dry inside the connector bush, then you can measure.
STORAGE RULES Until commissioning the OTDR should be stored in a warehouse under the following
conditions: • Ambient air temperature from 5 °C to 40 °С; • Relative air humidity up to 80 % by 25 °С.
The repository should be free of dust, acid and alkali vapors and gases that cause
corrosion. When the storage time exceeds one month the OTDR should be stored without the
rechargeable battery. To remove the battery unscrew the two screws on the left side panel of the OTDR, take out the battery and set the covers in place.
TRANSPORT Transportation of the OTDR must be carried out in closed vehicles of any kind (by
rail, road and river (in holds) transport). During transportation by air the OTDR must be placed in a heated sealed
compartment. The parameters of climatic impacts on the OTDR in packages during transportation
should be the following: • ambient air temperature from minus 20 to plus 50 °C • relative air humidity up to 98 % by 35 °С;
If the OTDR was transported at temperatures below 0 °C, it must be kept under normal conditions for 2 hours.
INFORMATION ABOUT PRECIOUS METALS CONTENT The instrument doesn't contain precious metals.
101
INSTRUMENT CALIBRATION
Verification Stages
Test type Designation of operations
Acceptance tests Periodic tests
External examination and testing Yes Yes
Dynamic range estimation Yes Yes
Dead zones estimation Yes Yes
Attenuation calibration Yes Yes
Distance calibration Yes Yes
Calibration Tools
Name of test equipment Note
Reference fiber 25 km
Match throttle 1 km (2 pcs.)
Use of other verification means is allowed that satisfy the requirements of this
technique.
102
Calibration Environment During verification the following conditions must be fulfilled:
• ambient air temperature (20±5) °С; • relative air humidity 30÷90 %; • atmospheric pressure 84÷106 kPa; • rechargeable battery completely charged.
Measuring instruments must be prepared for work in accordance with maintenance documentation.
Thoroughly clean the optical connectors before switching.
Calibration Procedure
External examination and testing During external examination the instrument compliance with the following
requirements should be identified: • completeness must meet the requirements of the log book; • all the inscriptions on the instrument must be clear and distinct; • the instrument shall not have mechanical damages on its housing and connecting
terminals. When testing, make sure that the display is operable. To do this, turn on the
instrument and sequentially switch the measurement modes. Hereby information in accordance with the user's guide must be displayed.
103
Dynamic range estimation • Connect the 25 km throttle to the instrument. • Set the following parameters:
o "Wavelength" = 1310 nm or 1550 nm o "Range" = 100 km o "Pulse width" = 20000 ns o "Resolution" = maximum o “Averaging in time” = ON o "Averaging time (minutes)" = 3 min. o "Refractive index" should be set for the fiber, on which
measurements are performed. o "Reduced laser power" = OFF o "High resolution" = OFF o "Filter" = OFF or ON
• To enter the main window press the [Trace] button. • Start measurement with the [Start] button.
After completion of trace acquisition carry out measurements.
104
Fig. 89. Measuring the dynamic range
To this effect: • Set the left marker just after the probe pulse. • Set the right marker to the maximum burst of noise outside the phantom reflection
area. Read the attenuation value D max. On the figure above D max = 35.456 dB. For precise positioning of the cursor use zoom function.
• Calculate the dynamic range D by the following formula:
21max DDDD δδ ++= 1Dδ - the ratio between the peak value of Gaussian noise and signal level equal to
the root-mean-square value of this noise (i.e. the level at which SNR = 1)
1Dδ = 2,4 dB 2Dδ –attenuation of the OF span between its start and the position of the left marker;
for its definition the trace should be mentally extended to the left from the left marker to the beginning of the distance scale and by the vertical scale the magnitude of increase in the level of trace should be determined. • Carry out similar measurements with the filter off. • Carry out similar measurements for a different wavelength. • Record results in the table.
105
Deadzone estimation • Connect the 1 km throttle to the instrument, to the end of this throttle connect one
1 km throttle more. • Set the following parameters:
o "Wavelength" = 1310 nm or 1550 nm o "Range" = 5 km o "Pulse width" = minimum o "Resolution" = minimum o “Averaging in time” = ON o "Averaging time (minutes)" = 3 min. o "Refractive index" should be set for the fiber, on which
measurements are performed. o "Reduced laser power" = OFF o "High resolution" = ON o "Filter" = OFF
• To enter the main window press the [Trace] button. • Start measurement with the [Start] button.
106
After completion of trace acquisition carry out measurements.
• Measure the deadzone by the attenuation as the distance from the reflection start to the point at which the signal level of the photodetector does not differ by more than 0.5 dB from the level of backscattering
Fig. 90. Attenuation dead zone (technique)
For precise positioning of the cursor use zoom function.
Fig. 91. Attenuation dead zone estimation
107
• Measure the event dead zone as the distance between the start of reflection and a point on the trailing edge of the reflection peak with level of 1.5 dB relative to the top.
Fig. 92. Event dead zone (technique).
For precise positioning of the cursor use zoom function.
Fig. 93. Deadzone estimation by reflection
• Carry out similar measurements for a different wavelength. • Record results in the table.
108
Attenuation calibration • Connect the 1 km throttle to the instrument, to the end of this throttle connect the
25 km throttle with the calibrated line attenuation. • Set the following parameters:
o "Wavelength" = 1310 nm or 1550 nm o "Range" = 75 km o "Pulse width" = 5000 o "Resolution" = minimum o “Averaging in time” = ON o "Averaging time (minutes)" = 3 min. o "Refractive index" should be set for the fiber, on which
measurements are performed. o "Reduced laser power" = OFF o "High resolution" = ON o "Filter" = OFF
• To enter the main window press the [Trace] button.
109
• After trace acquisition enable the LSA line mode, position the cursors at the end and beginning of the linear span of the trace and compare the measured value of the slope in dB/km with certified value of the used 25 km coil.
Fig. 94. Attenuation calibration (technique)
Fig. 95. Attenuation calibration
• Carry out similar measurements for a different wavelength. • Record results in the table.
110
Distance calibration • Connect the 1 km match throttle to the instrument, to the end of this throttle connect
the 25 km throttle with the calibrated refractive index and length. • Set the same parameters as by attenuation calibration:
o "Wavelength" = 1310 nm or 1550 nm o "Range" = 75 km o "Pulse width" = 5000 o "Resolution" = minimum o “Averaging in time” = ON o "Averaging time (minutes)" = 3 min. o "Refractive index" should be set for the fiber, on which
measurements are performed. o "Reduced laser power" = OFF o "High resolution" = ON o "Filter" = OFF
• To enter the main window press the [Trace] button.
111
• Start measurement with the [Start] button.
• After trace acquisition using zoom position the cursors exactly on the reflecting events of the start and end of a the calibrated optical fiber on the trace, and compare the derived distance with the certified value.
Fig. 96. Distance calibration (technique).
Fig. 97. Distance calibration
• Carry out similar measurements for a different wavelength. (specifying the refraction index).
• Record results in the table.
Calibration Interval Calibration of the instrument must be made at least 1 time in 12 months.
112
MANUFACTURER'S WARRANTY Warranty period is 1 year from a purchase date. The warranty is not applied to the
battery. All matters of warranty and post-warranty service of the instrument should be addressed to:
170043, TVER, post office box 43100 SVYAZPRIBOR Phone/Fax (4822) 42-54-91 www.svpribor.ru Technical support service: [email protected] When you send the instrument in for repair, please accompany it with the following
information: 1. Failure description 2. Comments or suggestions to the work of the instrument 3. Return address Please send the instrument for repair at the address: 170043 Tver, post office box 43100
ACCEPTANCE CERTIFICATE Instrument serial number _________ Date _________ Signature _________
113
CALIBRATION DATA Instrument No. _________________
Conditions Value
Puls
e
Filte
r
Wav
elen
gth
Ave
ragi
ng
time
(min
)
Res
olut
ion
Hig
h re
solu
tion
Nor
m
Act
ual v
alue
Dynamic range
20 000 ns IN 1310 3 worst-case OFF ≥34 dB
20 000 ns OFF 1310 3 worst-case OFF ≥32 dB
20 000 ns IN 1550 3 worst-case OFF ≥32 dB
20 000 ns OFF 1550 3 worst-case OFF ≥30 dB
Attenuation dead zone
8 ns OFF 1310 3 best-case ON ≤10 m
8 ns OFF 1550 3 best-case ON ≤10 m
Reflection dead zone
8 ns OFF 1310 3 best-case ON ≤3 m
8 ns OFF 1550 3 best-case ON ≤3 m
Distance
5 000 ns OFF 1310 3 best-case ON 25,2524 ÷25,2590 km
5 000 ns OFF 1550 3 best-case ON 25,2638 ÷25,2705 km
Attenuation
5 000 ns OFF 1310 3 worst-case ON 0,312 ÷ 0,344 dB/km
5 000 ns OFF 1550 3 worst-case ON 0,182 ÷ 0,202 dB/km
Calibrator Date
