EXFO FTB-5240S, FTB-5240BP User Manual

FTB-5240S/S-P/BP

Optical Spectrum Analyzer

User Guide

Copyright © 2009–2014 EXFO Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form, be it electronically, mechanically, or by any other means such as photocopying, recording or otherwise, without the prior written permission of EXFO Inc. (EXFO).

Information provided by EXFO is believed to be accurate and reliable. However, no responsibility is assumed by EXFO for its use nor for any infringements of patents or other rights of third parties that may result from its use. No license is granted by implication or otherwise under any patent rights of EXFO.

EXFO’s Commerce And Government Entities (CAGE) code under the North Atlantic Treaty Organization (NATO) is 0L8C3.

The information contained in this publication is subject to change without notice.

Trademarks

EXFO’s trademarks have been identified as such. However, the presence or absence of such identification does not affect the legal status of any trademark.

Units of Measurement

Units of measurement in this publication conform to SI standards and practices.

Patents

Feature(s) of this product is/are protected by one or more of US patents 6,636,306; 8,358,930; 8,364,034 and equivalent patents pending and granted in other countries; patent appl. US 2013/0163987 A1; and US patents 6,612,750 and 8,373,852.

Version number: 11.0.1

ii FTB-5240S/S-P/BP

Contents

Certification Information ....................................................................................................... vi

1 Introducing the FTB-5240S/S-P/BP Optical Spectrum Analyzer .................. 1

Models ....................................................................................................................................2

Typical Applications ................................................................................................................3

Optional Software Packages ...................................................................................................4

Post-Processing Application ....................................................................................................5

Conventions ............................................................................................................................6

2 Safety Information ....................................................................................... 7

3 Preparing Your OSA for a Test ..................................................................... 9

Cleaning and Connecting Optical Fibers .................................................................................9

Installing the EXFO Universal Interface (EUI) .........................................................................11

Selecting a Test Mode ...........................................................................................................12

Switching Modes While a Trace is Open ...............................................................................14

Nulling Electrical Offsets .......................................................................................................15

Performing User Calibration ..................................................................................................17

Using the Autonaming Feature .............................................................................................29

4 Setting Up the Instrument in WDM Mode ................................................ 33

Defining Preferences .............................................................................................................35

Setting Up WDM Analysis Parameters ...................................................................................51

Setting Up Acquisition Parameters ........................................................................................78

Using the Commissioning Assistant ......................................................................................82

5 Setting Up the Instrument in Drift Mode ................................................. 91

Defining Preferences .............................................................................................................93

Setting Up Drift Analysis Parameters ..................................................................................107

Setting Up Acquisition Parameters ......................................................................................131

Building a Custom Drift Measurement ................................................................................138

6 Setting Up the Instrument in DFB Mode ................................................ 149

Defining Preferences ...........................................................................................................150

Setting Up Acquisition Parameters ......................................................................................160

7 Setting Up the Instrument in FP Mode ................................................... 163

Defining Preferences ...........................................................................................................164

Setting Up Acquisition Parameters ......................................................................................173

OSA iii

8 Setting Up the Instrument in Spectral Transmittance Mode .................177

Defining Preferences ...........................................................................................................178

Setting Up Spectral Transmittance Analysis Parameters ......................................................187

Setting Up Acquisition Parameters .....................................................................................195

9 Setting Up the Instrument in EDFA Mode ...............................................199

Defining Preferences ...........................................................................................................201

Setting Up EDFA Analysis Parameters .................................................................................215

Setting Up Acquisition Parameters .....................................................................................232

10 Starting a Measurement ...........................................................................237

11 Managing Files and Test Configurations .................................................239

Using the Discover Feature .................................................................................................239

Managing Measurement Files .............................................................................................242

Opening Files in Other Test Modes ......................................................................................246

Managing Favorites ............................................................................................................250

Importing a Configuration from the Current Trace .............................................................260

Using a Restore Point ..........................................................................................................260

12 Managing Results .....................................................................................261

Managing WDM Test Results ..............................................................................................262

Managing Drift Test Results ................................................................................................276

Managing DFB Test Results .................................................................................................287

Managing FP Test Results ....................................................................................................291

Managing Spectral Transmittance Test Results ....................................................................295

Managing EDFA Test Results ...............................................................................................300

Adjusting the Display Size ...................................................................................................306

Viewing WDM Graph in Full-Screen Mode ..........................................................................308

Using Zoom Controls ..........................................................................................................309

Managing Markers .............................................................................................................311

Managing Trace Information ..............................................................................................315

Generating Reports .............................................................................................................319

13 Maintenance ..............................................................................................321

Cleaning EUI Connectors ....................................................................................................321

Recalibrating the Unit .........................................................................................................324

Recycling and Disposal (Applies to European Union Only) ..................................................325

14 Troubleshooting ........................................................................................327

Viewing Online Documentation ..........................................................................................327

Contacting the Technical Support Group ............................................................................328

Transportation ....................................................................................................................330

iv FTB-5240S/S-P/BP

15 Warranty ................................................................................................... 333

General Information ...........................................................................................................333

Liability ...............................................................................................................................334

Exclusions ...........................................................................................................................335

Certification ........................................................................................................................335

Service and Repairs .............................................................................................................336

EXFO Service Centers Worldwide ........................................................................................337

A Technical Specifications ........................................................................... 339

B SCPI Command Reference ....................................................................... 341

Quick Reference Command Tree .........................................................................................341

Product-Specific Commands—Description ..........................................................................349

Examples on Using the SCPI Commands .............................................................................598

C Formulas Used with Your Optical Spectrum Analyzer ............................ 619

EDFA Noise Figure Calculation ............................................................................................619

Central Wavelength Calculation (Spectral Transmittance) ...................................................620

Bandwidth Calculation (Spectral Transmittance) .................................................................621

Index .............................................................................................................. 623

OSA v

Certification Information

North America Regulatory Statement

This unit was certified by an agency approved in both Canada and the United States of America. It has been evaluated according to applicable North American approved standards for product safety for use in Canada and the United States.

Electronic test and measurement equipment is exempt from FCC part 15, subpart B compliance in the United States of America and from ICES-003 compliance in Canada. However, EXFO Inc. makes reasonable efforts to ensure compliance to the applicable standards.

The limits set by these standards are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the user guide, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.

Modifications not expressly approved by the manufacturer could void the user's authority to operate the equipment.

European Community Declaration of Conformity

An electronic version of the declaration of conformity for your product is available on our website at www.exfo.com. Refer to the product’s page on the Web site for details.

vi FTB-5240S/S-P/BP

1 Introducing the

Input port

Handle

FTB-5240S/S-P/BP Optical Spectrum Analyzer

The FTB-5240S/S-P/BP Optical Spectrum Analyzer (OSA) is designed to measure optical power as a function of wavelength or frequency and Optical Signal to Noise Ratio (OSNR).

Your OSA offers spectral characterization for CWDM/DWDM network component testing and manufacturing, network validation as well as commissioning, offering in addition InBand Optical Signal to Noise Ratio (OSNR) measurement for ROADM and 40 Gbit/s signals and networks, and Pol Mux OSNR for coherent 40 G/100 G networks.

OSA 1

Introducing the FTB-5240S/S-P/BP Optical Spectrum Analyzer

Models

The OSA comes in different models:

 5240S: The 5240S is a small form factor expert DWDM OSA designed for

efficient commissioning, maintenance and troubleshooting of DWDM components and links in the field, from 25 GHz to CWDM. It can measure power as a function of wavelength for new modulation schemes, such as non-return-to-zero (NRZ), duo binary, which present large line widths and often display multiple peaks. In-depth analysis ensures the correct identification and signal measurement of each carrier. It also measures OSNR based on the IEC 61280-2-9 method.

 5240S-P: It is the 5240S model with a polarization controller. It is a

hardware-ready version of an expert OSA, without the software to compute the InBand/i-InBand OSNR. You can upgrade this model using the software key, and it will become fully capable of InBand/i-InBand/Pol Mux OSNR measurement.

 5240S-P-InB: It is the 5240 S-P model with the software to compute the

InBand/i-InBand OSNR. This software allows you to make either IEC-Based OSNR measurements, or In-Band OSNR measurements, required when the inter-channel noise is not representative of the noise under the signal peaks or when crosstalk is dominant.

 5240BP: It is a three-slot high-resolution model with a polarization

controller for InBand and Pol Mux testing, and better optical performance. It is designed for accurate and precise spectral measurements, even for channels with 12.5 GHz spacing.

 High Power Model (HPW): This model allows you to connect the

FTB-5240S or FTB-5240S-P OSA to a network that carries very high optical power. This situation becomes more common with the deployment of latest CATV networks. The sensitivity of this OSA model is shifted accordingly and the module is protected to work under these extended power levels.

2 FTB-5240S/S-P/BP

Introducing the FTB-5240S/S-P/BP Optical Spectrum Analyzer

Typical Applications

You can use your OSA for the following tasks:

 Characterizing channels in the O- to U-band spectra

 Testing laser sources for spectral purity and power distribution

 Testing the transmission characteristics of optical devices

 Troubleshooting and monitoring key parameters on CWDM or DWDM

signals to check system stability

 Characterizing all channel spacings, from 25 GHz DWDM to CWDM

(from 12.5 GHz for 5240BP)

 Testing high-speed networks (beyond 40 Gbit/s)

 Measuring OSNR, but specifically within the channel (InBand or Pol

Mux OSNR) for 5240S-P-InB and 5240BP models

OSA 3

Introducing the FTB-5240S/S-P/BP Optical Spectrum Analyzer

Optional Software Packages

Optional software options are available for your application.

Option Name Description

Advanced (Adv) The Advanced option gives you access to the following test

modes:

 Drift: time-based WDM analysis for signal monitoring.

 ST: characterization of the spectral transmittance of

optical components such as filters.

 EDFA: characterization of the performance of an

Erbium Doped Fiber Amplifier.

 DFB: characterization of a DFB laser source.

 FP: characterization of a Fabry-Perot laser source.

In-Band (InB) The In-Band option enables you to perform In-Band noise

analysis for WDM and WDM drift measurements.

When this option is activated, it is possible to have access to user-defined acquisition and analysis parameters for custom In-Band noise measurement (WDM and WDM drift modes)

Note: Not supported by the 5240S module but

supported by the 5240S-P module.

Note: This feature is automatically available for the

5240BP module (no need to purchase the option).

4 FTB-5240S/S-P/BP

Introducing the FTB-5240S/S-P/BP Optical Spectrum Analyzer

Post-Processing Application

Option Name Description

WDM Investigator (Inv)

Commissioning (Com)

This option activates the WDM Investigator mode measurement diagnostics.

When this option is activated, it is possible to have access to qualitative analysis of the noise source in measurement results for each channel through the WDM Investigator dashboard.

 Qualitative analysis of the noise source in

measurement results for each channel through the WDM Investigator dashboard

 Qualitative analysis of the PMD pulse spreading on live

noncoherent signals

Note: Not supported by the 5240S module but

supported by the 5240S-P module.

Note: The WDM Investigator (Inv) software option

is dependent on the InBand (InB) option. The InBand (InB) option must be enabled for the WDM Investigator (Inv) software option to work.

The commissioning option can be used to test channels individually by comparing one channel at a time with a trace where all channels are enabled (or on).

Post-Processing Application

A post-processing, or offline version of the application is available for you to use on a conventional computer. This offline version has most of the module application, but does not allow you to perform acquisitions.

OSA 5

Introducing the FTB-5240S/S-P/BP Optical Spectrum Analyzer

Conventions

Before using the product described in this guide, you should understand the following conventions:

WARNING

Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury. Do not proceed unless you understand and meet the required conditions.

CAUTION

Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. Do not proceed unless you understand and meet the required conditions.

CAUTION

Indicates a potentially hazardous situation which, if not avoided, may result in component damage. Do not proceed unless you understand and meet the required conditions.

IMPORTANT

Refers to information about this product you should not overlook.

6 FTB-5240S/S-P/BP

2 Safety Information

WARNING

Do not install or terminate fibers while a light source is active. Never look directly into a live fiber and ensure that your eyes are protected at all times.

WARNING

The use of controls, adjustments and procedures, namely for operation and maintenance, other than those specified herein may result in hazardous radiation exposure or impair the protection provided by this unit.

IMPORTANT

When you see the following symbol on your unit , make sure that you refer to the instructions provided in your user documentation. Ensure that you understand and meet the required conditions before using your product.

IMPORTANT

Other safety instructions relevant for your product are located throughout this documentation, depending on the action to perform. Make sure to read them carefully when they apply to your situation.

CAUTION

The following symbol indicates that your unit is equipped with a laser source: .

OSA 7

Safety Information

Your instrument is a Class 1 laser product in compliance with standards IEC 60825-1: 2007 and 21 CFR 1040.10, except for deviations pursuant to Laser Notice No. 50, dated June 24, 2007. Invisible laser radiation may be encountered at the output port.

The following label indicates that a product contains a Class 1 source:

The maximum input power for the FTB-5240S/S-P/BP Optical Spectrum Analyzer is 4 W for S and S-P modules, and 6 W for BP modules. For more information on equipment ratings, refer to the user documentation for your platform.

8 FTB-5240S/S-P/BP

3 Preparing Your OSA for a Test

IMPORTANT

For optimal test results, you should allow a minimum warm up period of two hours for your OSA before starting your tests.

Cleaning and Connecting Optical Fibers

IMPORTANT

To ensure maximum power and to avoid erroneous readings:

 Always inspect fiber ends and make sure that they are clean as

explained below before inserting them into the port. EXFO is not responsible for damage or errors caused by bad fiber cleaning or handling.

 Ensure that your patchcord has appropriate connectors. Joining

mismatched connectors will damage the ferrules.

To connect the fiber-optic cable to the port:

1. Inspect the fiber using a fiber inspection microscope. If the fiber is

clean, proceed to connecting it to the port. If the fiber is dirty, clean it as explained below.

2. Clean the fiber ends as follows:

2a. Gently wipe the fiber end with a lint-free swab dipped in isopropyl

alcohol.

2b. Use compressed air to dry completely.

2c. Visually inspect the fiber end to ensure its cleanliness.

OSA 9

Preparing Your OSA for a Test

Cleaning and Connecting Optical Fibers

3. Carefully align the connector and port to prevent the fiber end from touching the outside of the port or rubbing against other surfaces.

If your connector features a key, ensure that it is fully fitted into the port’s corresponding notch.

4. Push the connector in so that the fiber-optic cable is firmly in place, thus ensuring adequate contact.

If your connector features a screwsleeve, tighten the connector enough to firmly maintain the fiber in place. Do not overtighten, as this will damage the fiber and the port.

Note: If your fiber-optic cable is not properly aligned and/or connected, you will

notice heavy loss and reflection.

EXFO uses good quality connectors in compliance with EIA-455-21A standards.

To keep connectors clean and in good condition, EXFO strongly recommends inspecting them with a fiber inspection probe before connecting them. Failure to do so will result in permanent damage to the connectors and degradation in measurements.

10 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Bare metal

(or blue border)

indicates UPC

option

Green border indicates APC

option

2 3 4

Installing the EXFO Universal Interface (EUI)

The EUI fixed baseplate is available for connectors with angled (APC) or non-angled (UPC) polishing. A green border around the baseplate indicates that it is for APC-type connectors.

To install an EUI connector adapter onto the EUI baseplate:

1. Hold the EUI connector adapter so the dust cap opens downwards.

2. Close the dust cap in order to hold the connector adapter more firmly.

3. Insert the connector adapter into the baseplate.

4. While pushing firmly, turn the connector adapter clockwise on the

baseplate to lock it in place.

OSA 11

Preparing Your OSA for a Test

Selecting a Test Mode

Your module gives you different ways to test all your DWDM systems:

 WDM: Allows you to analyze an optical link. By default, the WDM test

mode is selected.

 Drift: Allows you to monitor an optical link for a fixed duration.

 DFB: Allows you to characterize a DFB laser source.

 Fabry-Perot (FP): Allows you to characterize a Fabry-Perot laser source.

 Spectral Transmittance: Allows you to characterize the spectral

transmittance of optical components such as filters.

 EDFA: Allows you to characterize the performance of an Erbium Doped

Fiber Amplifier (EDFA) using the OSA module in field deployed systems (NB measurement assumes transmission conditions).

To select a test mode:

1. From the Main Menu, press Mode.

12 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Selecting a Test Mode

2. Select the desired test mode. The DFB and FP sources are under the

Sources item.

Once you select the mode, you will notice a against the selected mode and all the tabs on the main window and the main menu will change accordingly.

After selecting the test mode, you must configure it. You will find specific instructions for your test mode in the corresponding related chapters.

OSA 13

Preparing Your OSA for a Test

Switching Modes While a Trace is Open

If you switch test modes while a trace is already on-screen, the trace will be loaded in the new selected mode and analyzed using the current analysis setup, if the test modes are compatible.

WDM, Spectral Transmittance and EDFA test modes are made to ease the switch between the modes. The table below indicates the equivalencies between the trace types. For example, an active trace in WDM mode becomes an output trace in EDFA mode, and vice-versa.

WDM ST EDFA

Active Output Output

Reference Input Input

14 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Nulling Electrical Offsets

The offset nulling process provides a zero-power reference measurement, thus eliminating the effects of electronic offsets and dark current due to detectors.

Temperature and humidity variations affect the performance of electronic circuits and optical detectors. For this reason, EXFO recommends performing a nulling of the electrical offsets whenever environmental conditions change.

Nulling can be performed for all tests modes. In addition, a nulling is performed automatically each time you start the OSA application, and at regular intervals afterwards.

Note: You cannot perform an offset nulling in the offline version of the

application.

To perform an offset nulling:

1. From the main window, select the Acquisition tab.

OSA 15

Preparing Your OSA for a Test

Nulling Electrical Offsets

2. Disconnect any incoming signal to obtain an optimal accuracy.

3. Press Nulling.

You are notified that the nulling is in progress in the status bar. Nulling should be completed in a few seconds.

Note: Several features, such as the Start button and Discover, are not available

during the nulling process.

16 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Performing User Calibration

Calibrating your module can help you achieve better results. It is particularly important when the measurement accuracy is critical or when your OSA has experienced unusual shock or vibrations. To reach the highest possible accuracy, you can perform a wavelength or power calibration. Your OSA allows you to modify and read the user calibration values, revert to the factory calibration, load and save the modified user calibration file. The user configuration file (*.txt) contains the reference and modified wavelength and power values.

You can perform user calibration in any test mode. Select a test mode as explained in Selecting a Test Mode on page 12, and follow the procedures mentioned below for performing user calibration.

Note: The procedure for performing user calibration is the same for all test

modes. The procedure is explained with WDM mode only in this document.

IMPORTANT

For optimal results, you should allow a minimum warm up period of two hours for your OSA before performing user calibration.

IMPORTANT

You must clear the correction factor list before making new calibration measurements. If calibration measurements are made when user correction factors are inside the module, the latter will affect the measurements and the calibration results become inapplicable.

Note: If you want to keep the correction factor list for a later use, save it under a

different name in the folder.

Note: The user calibration feature is not available in the offline version of the

application.

OSA 17

Preparing Your OSA for a Test

Performing User Calibration

To perform a user calibration:

1. Allow your unit to warm up.

2. From the Main Menu, press Analysis Setup.

18 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Performing User Calibration

3. Select the Calibration tab.

Note: You cannot edit the power or wavelength values directly from the

application. The modifications in the user calibration have to be made in a text file, and then it can be loaded in the application.

OSA 19

Preparing Your OSA for a Test

Performing User Calibration

4. If user correction factors are in the system, press Clear User Correction Factors from Module, then confirm your choice.

5. Take measurements for your test mode.

20 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Performing User Calibration

6. Note the measurements to a .txt file using the following format:

 The first column is the reference wavelengths, in nm.

 The second column is the wavelength read by your module, in nm.

 The third column is the reference power, in dBm.

 The fourth column is the power read by your module, in dBm.

Note: The columns are separated by a semi-colon (;). You can have up to 100

calibration points.

Here is an example of a measurement file:

1310.154; 1310.167; -1.34; -1.55

1490.000; 1490.000; 1.09; 1.15

1551.334; 1551.298; -5.20; -5.45

1625.401; 1625.448; 0.00; 0.00

Note: The decimal separator is a point ( . ). This format is independent of the

regional settings.

7. Save your .txt file in a location of your choice.

OSA 21

Preparing Your OSA for a Test

Performing User Calibration

8. Back in the Calibration tab on your unit, load the file using Load Factors.

9. Select the modified user calibration file and press Open.

22 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Performing User Calibration

The calibration values will replace the Correction factors list in the Analysis setup - Calibration window.

OSA 23

Preparing Your OSA for a Test

Performing User Calibration

10. Press Write to Module to apply the modified calibration values to the module.

24 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Performing User Calibration

11. To verify that the calibration changes are properly applied to the module, press Load from Module.

Note: The OK and Cancel buttons do not have any impact on the calibration

page or the correction factors inside the module.

OSA 25

Preparing Your OSA for a Test

Performing User Calibration

To save a user calibration:

1. From the Main Menu, press Analysis Setup.

26 FTB-5240S/S-P/BP

2. Select the Calibration tab.

Preparing Your OSA for a Test

Performing User Calibration

OSA 27

Preparing Your OSA for a Test

Performing User Calibration

3. Press Save Factors, to save the modified user calibration values.

28 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Using the Autonaming Feature

Defining a file autonaming format will allow you to quickly and automatically name traces in a sequential order. The customized name appears when the file is saved using the Save As option. You can select which fields you want to include in the file name and the order in which they should be displayed.

The Link ID is used by the application to suggest a file name when you want to save the current acquisition. The link parameters are prefix and suffix values (file names) for the link IDs.

Note: The autonaming feature is not available in the offline application.

Note: The procedure below uses the WDM test mode as an example, but the

autonaming feature is available for all test modes.

OSA 29

Preparing Your OSA for a Test

Using the Autonaming Feature

To customize the file name:

1. From the Main Menu, press Preferences.

30 FTB-5240S/S-P/BP

Preparing Your OSA for a Test

Using the Autonaming Feature

2. Select the File Name tab.

3. Select which parameters you want to include in the file name from the

list of available choices:

 Wavelength/frequency range: current wavelength/frequency

acquisition range.

 Acquisition type: current acquisition type.

 Scan count: current number of scans in the acquisition tab.

 Link ID: prefix value for the link ID configured in the

Preferences-Information tab.

 Cable ID: prefix value for the cable ID configured in the

Preferences-General tab.

 Fiber ID: prefix value for the fiber ID configured in the

Preferences-General tab.

 Location description: location description provided in the

Preferences-Information tab.

OSA 31

Preparing Your OSA for a Test

Using the Autonaming Feature

4. Press the up or down arrows to change the order in which the field values will appear in the file name.

Based on your selection, a preview of the file name is displayed under File name preview. The field values are separated with an underscore ( _ ).

5. Press OK to save the changes and close the window, or press Cancel to exit without saving.

Press Restore Defaults to remove all the changes and apply the default settings.

32 FTB-5240S/S-P/BP

4 Setting Up the Instrument in

WDM Mode

Before performing a spectral analysis in the WDM mode, you must set up the test application with the appropriate parameters, as explained in this chapter.

Select the WDM test mode as explained in Selecting a Test Mode on page 12 before setting up the WDM test parameters.

 The preferences are the result displayed in the graph and tables, as

well as the job information and related comments saved with each file.

 The analysis parameters include the channel list details, pass-fail

threshold settings and allows you to select the noise and power calculation methods.

 The acquisition parameters include the type of measurement you want

to perform and the wavelength range.

See Defining Preferences on page 35, Setting Up WDM Analysis Parameters on page 51 and Setting Up Acquisition Parameters on page 78 for more details.

OSA 33

Setting Up the Instrument in WDM Mode

You can set up your unit in different manners, depending on your testing needs.

 The preferred way is to use the complete analysis setup parameters

and complete the information in all tables, as explained in Setting Up WDM Analysis Parameters on page 51. This setup will be used for the

next acquisition.

 The easiest way to set up the instrument, especially when the operator

does not know in advance what to expect at the input of the module is to use the Discover button. After the Discover button has been pressed, a measurement and analysis will be performed according to the best setup determined by the instrument and this setup will be used for the next scan. This is explained in Using the Discover Feature on page 239.

 The most efficient way to set up the instrument is to use one of the

favorites configurations, uploading a pre-customized acquisition and analysis setup configuration. The operator in the field only has to press the button, select the appropriate configuration and press Start. As an example, a pre-customized configuration could be: “32 channels DWDM 50GHz”; “Toronto-Montreal CWDM” or “Vendor ABC DWDM ROADM 40Gb”. This is explained in Managing Favorites on page 250.

 You can also import the setup from the current trace. This method will

take the data and channel information from the current trace and apply them in the corresponding tabs. For more information, see Setting Up WDM Analysis Parameters on page 51.

34 FTB-5240S/S-P/BP

Setting Up the Instrument in WDM Mode

Defining Preferences

The preferences window allows you to set general information and comments on trace, set display parameters and customize the WDM results table.

Note: Only the Display and WDM Results tabs are available in offline mode.

Defining Trace Information

The trace information relates to the description of the job to be done, cable and job IDs, and any relevant information about what is being tested.

To enter general information:

1. From the Main Menu, press Preferences.

OSA 35

Setting Up the Instrument in WDM Mode

Defining Preferences

2. Select the General tab.

3. Define the general parameters as needed.

4. Press OK to save the changes and close the window, or press Cancel to

exit without saving.

Press Clear to clear all the changes made in the General tab.

36 FTB-5240S/S-P/BP

Setting Up the Instrument in WDM Mode

To enter link and location information:

1. From the Main Menu, press Preferences.

2. Select the Information tab.

Defining Preferences

OSA 37

Setting Up the Instrument in WDM Mode

Defining Preferences

3. Under System and link information, define the following parameters as needed:

 Link ID prefix: The prefix value for the link ID. You can enter any

alphanumeric value.

 Starting value: The suffix increment starting value for the link ID.

This value is incremented each time a new file is saved provided the Auto Increment option is selected.

IMPORTANT

If the Auto Increment option is not selected, you have to manually change the file name when saving the trace file, otherwise the application will overwrite the previously saved file.

 Orientation: The orientation of the link.

 System: Information about the system under test.

38 FTB-5240S/S-P/BP

Setting Up the Instrument in WDM Mode

Defining Preferences

4. Under Location Information, define the following parameters as needed:

 Network element: Sets the type of network element.

 Test point: Sets the location where the test is performed on the

link.

 Description: Enter the description of location if required.

5. Press OK to save the changes and close the window, or press Cancel to exit without saving.

Press Restore Defaults to remove all the changes and apply the default values.

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Setting Up the Instrument in WDM Mode

Defining Preferences

To enter comments:

1. From the Main Menu, press Preferences.

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Setting Up the Instrument in WDM Mode

Defining Preferences

2. Select the Comments tab.

3. Enter your comments for the current trace.

4. Press OK to save the changes and close the window, or press Cancel to

exit without saving.

Press Clear to clear all the changes made in the Comments tab.

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Setting Up the Instrument in WDM Mode

Defining Preferences

Defining Display Parameters

The application allows you to set display settings for the acquisition trace. You can set the spectral unit for the trace and the results table. You can also select the label that should appear on the peaks of the trace.

To define display parameters:

1. From the Main Menu, press Preferences.

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Setting Up the Instrument in WDM Mode

Defining Preferences

2. Select the Display tab.

3. Select the spectral unit you want to work with, either nm or THz.

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Setting Up the Instrument in WDM Mode

Defining Preferences

4. Select the label that will appear on the peaks in the graph, either the channel name, its number, or nothing.

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Channel numbers

Defined channel names

Defining Preferences

Note: The channel name and channel number cannot be shown at the same

time.

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Setting Up the Instrument in WDM Mode

Defining Preferences

5. Select whether you want to show or hide the empty channels from the channel list in the Results tab.

Note: When selected, empty channels are shown on screen and in the report files.

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Setting Up the Instrument in WDM Mode

Defining Preferences

6. Select whether you want to show the horizontal markers or the

integrated power and the  trace in the marker toolbar.

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Setting Up the Instrument in WDM Mode

Defining Preferences

7. Select the background color scheme for the graph as desired.

8. Press OK to save the changes and close the window, or press Cancel to

exit without saving.

Press Restore Defaults to remove all the changes and apply the default values.

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Setting Up the Instrument in WDM Mode

Defining Preferences

Customizing WDM Results Table

It is possible to select which results you would like to be displayed in the Results tab of your WDM tests.

To customize the results table:

1. From the Main Menu, press Preferences.

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Setting Up the Instrument in WDM Mode

Defining Preferences

2. Select the WDM Results tab.

3. Select which parameters you want to display in the Results tab from

the list of available choices:

 Name: name of channel.

 (Center wavelength/frequency): spectral center-of-mass for the

peak in that channel.

 Signal Power: signal power for the selected channel (excludes

noise).

 OSNR: optical signal to noise ratio, given by Signal power

(according to the current calculation method, in dBm), minus Noise (according to the current calculation method, in dBm).

 Noise: noise level for the selected channel. The type of noise is

indicated in front of the measurement (IEC, Fit, Inb, Inb nf, IECi, CCSA ).

 BW 3.00 dB: bandwidth measured by taking the width of a signal at

50 % linear power of the peak, or -3 dB from the peak.

 BW at x dB: bandwidth measured by taking the width of a signal at

x dB from the peak.

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Setting Up WDM Analysis Parameters

 /f : deviation of the spectral center of mass for the peak in that

channel.

 /f Peak: spectral peak in that channel.

 /f Peak: deviation of the spectral peak in that channel.

4. Press the up or down arrows to change the order in which the columns will appear in the Results tab.

5. Press OK to save the changes and close the window, or press Cancel to exit without saving.

Press Restore Defaults to remove all the changes and apply the default values.

Setting Up WDM Analysis Parameters

This section presents the various analysis settings for the application, particularly the channel list and settings. You can set the default channel parameters, channel list, global thresholds, default channel thresholds, manage favorite configurations and perform user calibration.

Note: When you change the analysis setup parameters, the new settings are

active as soon as you confirm your choice. The current trace is re-analyzed, and the analysis setup parameters will be applied to the global results and channel results for the following acquisitions.

You can either set each parameter individually, or use parameters from the current trace and import them.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

To import the parameters from the current trace:

1. Make sure that you have a trace on-screen.

2. From the Main Menu, press Analysis Setup.

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Setting Up WDM Analysis Parameters

3. From any tab, press Import from Trace.

4. Press OK to confirm the changes.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

Defining General Settings

The general analysis parameters for WDM acquisitions affect the calculation of the results. Any change you make to the settings affect future traces, or you can apply them to the active trace when reanalyzing it.

IMPORTANT

In the General tab, you can set the default channel parameters. Any channel found during an acquisition that is not defined in the channel list will be analyzed according to the default channel settings.

To define general settings:

1. From the Main Menu, press Analysis Setup.

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2. Select the General tab.

Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

3. Under Default channel settings, define the following parameters as needed:

 Clear the Activate default channel option to use the currently

defined channel list for analysis. This reduces the analysis time by eliminating the peak detection over the complete spectral range. The peaks outside the defined channel list will not be analyzed.

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Setting Up WDM Analysis Parameters

 Channel width (GHz or nm): indicates the limit inside which the

power values will be considered in the channel.

For default channels, the channel width that sets the limits of the channel, should be the same as the channel distance or smaller (channel distance is defined while creating a channel list). If the channel width is not compatible with the channel spacing, either a single peak may be found for two distinct channels and two analysis would be performed and displayed for that peak, or, it is possible that two peaks may be found within the same channel and be considered as one multi-peak signal. With this result, you can use markers to find the spacing between adjacent channels or to find the channel width.

 Snap to ITU Grid: When selected, each detected peak will be

defined by the nearest ITU channel. The ITU grid is based on the selected channel width.

 Signal power calculation: indicates which calculation method to

apply for signal power value.

Integrated signal power: The integrated signal power represents the sum of the power values included between the channel limits of this channel, minus the estimated noise contribution between the same boundaries. In some cases, for instance CATV signals, signals with high-frequency modulation, or signals with an inherent line width similar or larger than the OSA's resolution bandwidth, this calculation becomes a better estimation of the true signal power.

Peak signal power: The peak signal power represents the maximum power value inside the channel. Note that it differs a little from the peak measurement on the spectrum due to the fact that the estimated noise is subtracted to get the peak signal power.

Total channel power: The total channel power represents the sum of the integrated signal power and of the noise within the channel. The OSNR calculation is not performed when the signal power calculation type is the total channel power.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

 Noise for OSNR: indicates which calculation method to use for

OSNR value.

Fixed range IEC based (IEC): The IEC method uses the interpolation of noise measured on both sides of the signal to estimate the noise level. The position at which the noise is estimated from the center wavelength is given by the OSNR distance.

InBand (InB): The InBand method uses a series of scans having different polarization states to calculate the noise level under the peak (InBand).

InBand narrow filter (InB nf): The InBand narrow filter method uses additional processing to provide an accurate OSNR value for the narrow carved noise. This is because with narrow filters, the noise level under the peak is not uniform and the OSNR value depends on the processing width selected.

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Channel width

Noise

region

OSNR

distance

Exclusion

zone

OSNR

distance

Noise

region

Channel center

Setting Up WDM Analysis Parameters

 Fifth order polynomial fit (Fit): The fifth order polyfit method

calculates the noise curve and thus the signal to noise ratio. The OSA will approximate the noise curve using a fifth order polynomial fit. This fit definition relies on fit and exclusion zones. Only the points in the fit zones are used to calculate the fifth order polynomial fit. If you select the fifth order polyfit method, you have to define the fit and exclusion zones for your tests using the OSNR distance and noise region fields. The exclusion zone is indirectly obtained from the OSNR distance.

 OSNR distance (GHz or nm): Except for the fifth order polyfit

selection, the OSNR distance is automatically set at the channel edge, that is, at half of the channel width from the center wavelength.

For the fifth order polyfit, the OSNR distance corresponds to the distance from the channel peak to the center of the fit zone. It is independent of the channel width.

 Noise region: The noise region, or fit zone, defines the region

where the polynomial fit applies. Two identical regions are centered at the OSNR distance.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

4. Under Global analysis parameters, define the following parameters as needed:

 Peak detection level (dBm): indicates the minimum power level

from where the peak can be considered as a signal.

 RBW for OSNR (nm): indicates the resolution bandwidth selected

for the OSNR calculation. This parameter is generally set to 0.1 nm to allow for a common basis of comparison between different OSAs having different effective resolutions. The instrument’s RBW value is written below the graph. This parameter does not actually have an effect on the acquisition, but is only a normalization factor used to provide the OSNR value in a standardized manner.

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Setting Up WDM Analysis Parameters

 Wavelength offset (nm): indicates the offset value applied on the

wavelength. This does not replace a calibration performed at EXFO, but it can help you temporarily sharpen the specifications if you have determined that, for example, your modules are used beyond the normal allowed use. Entering a value in THz is not possible. When an offset is applied, it is indicated at the bottom of the graph ( ).

 Power offset (dB): indicates the offset value applied on the power.

This does not replace a calibration performed at EXFO, but it can help you achieve the specifications if you have determined that, for example, your modules are used beyond the normal allowed use. When an offset is applied, it is indicated at the bottom of the graph (P ).

To edit the power offset as a tap percentage, press the Edit % button.

The percentage value entered in Edit percentage will be converted to a corresponding equivalent value in dB.

 Bandwidth at (dB): Set the power level used, relative to the

channel peak power, to compute the second bandwidth result.

5. Press OK to save the changes and close the window, or press Cancel to exit without saving.

Press Restore Defaults to remove all the changes and apply the default values.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

Defining Global Thresholds

Any change you make to the global threshold settings affect future traces, or you can apply them to the active trace when reanalyzing it.

The application allows you to activate and deactivate the threshold functionality with a single control. When thresholds are globally enabled, the results are displayed with the Pass/Fail status based on various settings (global results, channel results). In addition, a global pass/fail status is also displayed in the Global Results tab (See Global Results Tab on page 270).

When thresholds are globally disabled, results are displayed without a Pass/Fail status and the Global pass/fail status will not be active in the Global Results tab. The P/F column under the results table will not be displayed.

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Setting Up WDM Analysis Parameters

You can set your pass/fail threshold limits in different ways depending on the type of test you are performing.

Threshold Limit Definition

None No threshold limit is set. The results will be displayed without a

Pass/Fail verdict.

Min. only The threshold limit is set for a minimum value only. The

Pass/Fail verdict is declared as Pass (in green), when the value is equal to or greater than the minimum threshold set. The verdict is declared as Fail (in red), when the value is below the minimum threshold set.

Max. only The threshold limit is set for a maximum value only. The

Pass/Fail verdict is declared as Pass (in green), when the value is equal to or less than the maximum threshold set. The verdict is declared as Fail (in red), when the value is above the maximum threshold set.

Min. and Max. The threshold limit is set for the minimum and maximum value.

The Pass/Fail verdict is declared as Pass (in green), when the value is equal to or within the minimum and maximum thresholds set. The Pass/Fail verdict is declared as Fail (in red), when the value is beyond the minimum or maximum thresholds set.

Use Default When this limit is set, the corresponding threshold set for the

default channels in the Analysis Setup tab will be applied to the channel.

Max. Deviation The threshold limit is set for the deviation value. The Pass/Fail

verdict is declared as Pass (in green), when the value is equal to or within the deviation threshold set. The Pass/Fail verdict is declared as Fail (in red), when the value is beyond deviation threshold set.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

To define global thresholds:

1. From the Main Menu, press Analysis Setup.

2. Select the Global Thresholds tab.

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Setting Up WDM Analysis Parameters

3. Select the Activate all thresholds option to manually set the global threshold values. If this option is not selected, all the thresholds will be deactivated, results are displayed without a Pass/Fail status and Global pass/fail status are not active in the Global Results tab.

4. Enter values in the boxes as explained below:

 Average signal power (dBm): the sum of the signal powers of all

the peaks detected in the current acquisition, divided by the total number of peaks.

 Signal power flatness (dB): the difference between the maximum

and minimum signal power values of the detected peaks, in dB.

 Average OSNR (dB): the sum of the entire OSNR of the peaks

detected in the current acquisition, divided by the total number of peaks.

 OSNR flatness (dB): the difference between the maximum and

minimum OSNR values of the detected peaks, in dB.

 Empty channel count: The number of empty channels from the

channel list.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

5. Press OK to save the changes and close the window, or press Cancel to exit without saving.

Press Restore Defaults to remove all the changes and apply the default values.

Defining Default Thresholds

Default thresholds will be applied to any channel found outside the channel list during the acquisition or re-analysis.

Note: The default thresholds settings are enabled only when the Activate all

thresholds option is selected in the Global Thresholds tab. For more

information, see Defining Global Thresholds on page 62.

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Setting Up WDM Analysis Parameters

You can set your pass/fail threshold limits in different ways depending on the type of test you are performing.

Threshold Limit Definition

None No threshold limit is set. The results will be displayed without a

Pass/Fail verdict.

Min. only The threshold limit is set for a minimum value only. The

Max. only The threshold limit is set for a maximum value only. The

Min. and Max. The threshold limit is set for the minimum and maximum value.

Max. Deviation The threshold limit is set for the deviation value. The Pass/Fail

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

To define default Thresholds:

1. From the Main Menu, press Analysis Setup.

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Setting Up WDM Analysis Parameters

2. Select the Default Thresholds tab.

3. Enter values in the boxes as explained below:

 Wavelength/Frequency (nm/GHz): the channel’s central

wavelength/frequency.

 Signal power (dBm): the signal power for the default channel

(excludes noise).

 Noise (dBm): the level of the noise for the selected channel.

 OSNR (dB): the optical signal to noise ratio, given by Signal power

(according to the current calculation method, in dBm) minus Noise (according to the current calculation method, in dBm).

4. Press OK to save the changes and close the window, or press Cancel to exit without saving.

Press Restore Defaults to remove all the changes and apply the default values.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

Managing Channels

Testing DWDM systems involves characterizing multiple signals in a link. The application allows you to define channels using a channel editor or quickly generate them from the current data. You can also rapidly create a list of equally spaced channels. Once a channel list is created, you can modify it as needed. You can edit the analysis parameters for one channel or multiple channels.

While creating the channel list, some channels may overlap. When the channel widths are specified in nm, two channels are considered to be overlapping when more than 1.2 GHz (approximately) of frequency range is common between the two channels.

To add a channel list:

1. From the Main Menu, press Analysis Setup.

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Setting Up WDM Analysis Parameters

2. Select the Channels tab.

3. By default, the channel list is empty. Press Add Channels.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

4. Enter values in the boxes as explained below:

 Start range (nm or THz): starting range of the channel list.

 Stop range (nm or THz): ending range of the channel list.

 Channel center wavelength/frequency: spectral center-of-mass for

the peak in that channel.

Note: When using the custom channel center wavelength option, the first channel

will be centered at the Start Range, and the list will be created using channel distance and channel width.

 Channel distance (nm or GHz): distance between channels. The

value of channel distance will be set depending on the selection made for the channel center wavelength option. The channel distance box will be enabled only when the channel center wavelength option is set to custom.

 Channel width (nm or GHz): limit inside which the power values

will be considered in the channel. Integrated power is calculated on channel width.

 Name prefix: adds a prefix to the channel names.

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Setting Up WDM Analysis Parameters

 Starting value: sets the increment starting value for the channel

name in the channel list.

 Increment value: sets the increment value for the channel name in

the channel list.

5. Press OK to return to the Channels window, which now lists the added channels.

Note: When new channels are added, the Use Default thresholds selection will

be applied to the channel parameters.

Note: A warning message will be displayed if channels are overlapping, but the

analysis can still be performed on overlapping channels. If any duplicate channels are added, a confirmation message will be displayed to overwrite the existing channels with the duplicate channels.

6. Press OK to save the changes and close the window, or press Cancel to exit without saving.

Note: The application displays a message if more than 1000 channels are added.

You ca n ex it the Analysis Setup window only after deleting the extra channels from the channel list. You can delete the channels manually as required.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

To edit the parameters of a specific channel:

1. From the Main Menu, press Analysis Setup.

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Setting Up WDM Analysis Parameters

2. Select the Channels tab.

3. Select the channel or channels to be modified in the channel list.

If you want the changes to be applied to all of your channels, press Select All. Channels can be selected one by one or all together. You can press Unselect All to clear all channel selections. To delete the selected channels, press Delete.

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Setting Up the Instrument in WDM Mode

Setting Up WDM Analysis Parameters

4. Press Edit Selection.

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Setting Up WDM Analysis Parameters

5. Modify the settings as needed. For more information about the settings, see Defining General Settings on page 54 and Defining Default Thresholds on page 66. If you leave a box empty, it will remain as it was before your changes. Modify appropriate settings.

6. Press OK to return to the Channels tab, which now contains the modified settings.

7. Press OK to save the changes and close the window, or press Cancel to exit without saving.

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Setting Up the Instrument in WDM Mode

Setting Up Acquisition Parameters

Before performing your test, you must set the acquisition type and parameters.

There are five types of acquisitions in WDM mode:

 Single: Spectral measurement is performed once. The results are

displayed according to this measurement.

 Averaging: Spectral measurements are performed based on the

number of scans that you have entered for this parameter. The trace will be displayed after each acquisition and averaged with the previous traces.

 Real-Time: In real-time acquisition, spectral measurements are

performed continuously until you press Stop. No averaging is done for spectral measurements. The graph and results are refreshed after each acquisition.

 InBand: The InBand type acquisition will perform a series of scans in

different polarization conditions in order to enable the InBand OSNR calculation.

 i-InBand: The i-InBand acquisition enables an adaptive intelligent

InBand OSNR calculation that takes into account the multiple scans (up to 500) in various polarization conditions to determine the best available InBand analysis parameters for the signals under test on a per channel basis. With this acquisition type, you do not need to make difficult parameter setting choices (the InBand or InBand narrow filter and number of scans are automatically determined), especially when you are faced with complex system configurations.

Note: The InBand and i-InBand option are available only if the module supports it

and you have purchased the corresponding InB software option.

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Setting Up the Instrument in WDM Mode

Setting Up Acquisition Parameters

Before performing measurements on an optical spectrum, you must select the wavelength/frequency range to use. You can perform the scan on the full range, on spectral bands, or select a custom range.

Note: The shorter the wavelength or frequency range, the faster the acquisition.

To set parameters in the Acquisition tab:

1. From the main window, select the Acquisition tab.

2. Select the acquisition type.

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Setting Up the Instrument in WDM Mode

Setting Up Acquisition Parameters

3. If you are performing an averaging type acquisition, enter the number of scans the unit will perform.

If you are performing an InBand type acquisition, either enter the number of scans or select a predefined number of scans the unit will perform.

Note: You cannot modify the number of scans count value if you are performing a

single or real-time or i-InBand acquisition.

Note: In i-InBand mode, the scan count value is always set to 500.

4. Select the wavelength range for your acquisition.

You can select the wavelength range by entering the start and stop values or by selecting a range on the double slider.

To select the wavelength range using the double slider, move the left and right handles on the double slider or simply click on any band.

Note: You can select more than one adjoining ranges to include in your range, for

example, S + C.

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Setting Up Acquisition Parameters

The wavelength range covered within these bands of the spectra are listed below.

 O band (original): 1255 to 1365 nm

 E band (extended): 1355 to 1465 nm

 S band (short wavelengths): 1455 to 1535 nm

 C band (conventional “erbium window”): 1525 to 1570 nm

 L band (long wavelengths): 1560 to 1630 nm

 U band (ultralong wavelengths): 1620 to 1650 nm.

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Setting Up the Instrument in WDM Mode

Pol Mux OSNR 10log10PN–n2=

Using the Commissioning Assistant

If you have purchased the commissioning (Com) option, you can use an assistant to calculate the OSNR of coherent channels.

The assistant lets you select a measurement file where all channels are on, or active, and then compares them to other measurement files on which one of the channels is off while all of the others are still on.

The commissioning assistant automates OSNR measurements of 40 G/100 G coherent signals based on two standards: the China Communications Standards Association (CCSA) YD/T 2147-2010 and the IEC recommendation 61282-10 (draft).

The Chinese CCSA YD/T 2147-2010 standard recommends calculating Pol-Mux OSNR as follows:

where, for a 50 GHz channel:

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 P is the integrated power (Signal + Noise) over the 0.4 nm channel

bandwidth

 N is the integrated power (Noise) over 0.4 nm bandwidth

 n is the integrated power (Noise) inside 0.2 nm, then normalized to

0.1 nm

Setting Up the Instrument in WDM Mode

-----

s 



-----------

d





Using the Commissioning Assistant

The IEC 61282-12 recommendation has not yet reached final approval stage, and therefore the calculation might differ slightly from that presented in this document. The standard defines OSNR as

OSNR (dB) = 10log (R) with

where:

 s(



): is the time-averaged signal spectral power density, not including

ASE, expressed in W/nm.



(

) is the ASE spectral power density, independent of polarization,

expressed in W/nm.

 B

is the reference bandwidth expressed in nm (usually 0.1 nm if not

otherwise stated) and the integration range in nm from 

to 2 is

chosen to include the total signal spectrum.

Note: To be valid, the trace with all channels on, or all of the traces with a

channel off must come from a module onto which the commissioning option was activated.

Note: The units and empty channel display information come from the user

preferences set in your application.

IMPORTANT

When performing OSNR measurements using the Commissioning Assistant, you must make sure that the noise level with the channel shutdown is representative of the real ASE noise level. For instance, ROADM equalization capabilities might change the noise level to compensate for the loss of one channel in the off trace measurement.

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Setting Up the Instrument in WDM Mode

Using the Commissioning Assistant

To use the commissioning assistant:

1. Review the analysis parameters of the trace you want to use with all

channels on. This is the key measurement trace for the rest of the operation.

2. From the main window, select Assistants, then Commissioning.

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Using the Commissioning Assistant

3. When you are ready to proceed, press either the right arrow button, or

On-channel trace.

4. Select the trace that will be used with all channels ON. This trace can be the one presently in memory (active trace only, not the reference trace), or you can select another one that you have previously stored. Once the measurement file is selected, you can see at the bottom of the window whether this measurement is compatible or not for commissioning.

Note: EXFO recommends setting the acquisition type to i-InBand or InBand (with

a minimum of 100 scans) to acquire this trace.

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Setting Up the Instrument in WDM Mode

Using the Commissioning Assistant

5. Once your choice is done, press the arrow button, or OFF-channel traces.

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Using the Commissioning Assistant

6. Using the buttons at the bottom of the window, select all of the applicable measurements traces (files) with one corresponding channel off. An indicator next to the trace shows if the measurement file is compatible or not.

Note: EXFO recommends setting the acquisition to a minimum of 8 scans.

Once the traces are selected, press the arrow button, or Channel matching review.

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Setting Up the Instrument in WDM Mode

Using the Commissioning Assistant

7. When channels can be associated automatically and that there is only one possible choice, the corresponding measurement file appears in the list. If no traces match some of the channels, they will be set to none.

In the case of channels where there is more than one corresponding measurement file, select which measurement you want to use for the commissioning test using the choices in the drop-down lists.

Note: You can go back in the assistant step to select or modify traces. However, if

you do, the matches in the Channel matching review page will not be automatically reassigned and you have to perform a manual assignment (association) for the channels with modified or new measurement files.

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Using the Commissioning Assistant

8. Select the type of analysis used to perform the noise calculation (CCSA or IECi, as explained on page 82).

9. When all channels are matched (or explicitly excluded when marked None), press OK to complete the analysis process and close the Assistant.

The results appear on-screen in the Results table and Channel Results tab. The type of analysis is indicated between parentheses. Non-selected channels will be re-analyzed with their current (trace with all channels on) settings.

Note: To keep the results you have just obtained with the commissioning

assistant, you must save your measurement trace.

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5 Setting Up the Instrument in

Drift Mode

Before performing a spectral analysis in the Drift mode, you must set up the test application with the appropriate parameters, as explained in this chapter.

Select the Drift test mode as explained in Selecting a Test Mode on page 12 before setting up the Drift test parameters.

 The preferences are the result displayed in the graph and tables, as

well as the job information and related comments saved with each file.

 The analysis parameters include the channel list details, pass-fail

threshold settings and allows you to select the noise and power calculation methods.

 The acquisition parameters include the type of measurement you want

to perform and the wavelength range.

See Defining Preferences on page 93, Setting Up Drift Analysis Parameters on page 107 and Setting Up Acquisition Parameters on page 131 for more details.

OSA 91

Setting Up the Instrument in Drift Mode

You can set up your unit in different manners, depending on your testing needs.

 The preferred way is to use the complete analysis setup parameters

and complete the information in all tables, as explained in Setting Up Drift Analysis Parameters on page 107. This setup will be used for the

next acquisition.

 The easiest way to set up the instrument, especially when the operator

 The most efficient way to setup the instrument is to use one of the

 You can also import the setup from the current trace. This method will

take the data and channel information from the current trace and apply them in the corresponding tabs. For more information, see Setting Up Drift Analysis Parameters on page 107.

92 FTB-5240S/S-P/BP

Setting Up the Instrument in Drift Mode

Defining Preferences

The preferences window allows you to set general information and comments on trace, set display parameters and customize the drift results table.

Note: Only the Display and Drift Results tabs are available in offline mode.

Defining Trace Information

The trace information relates to the description of the job to be done, cable and job IDs, and any relevant information about what is being tested.

To enter general information:

1. From the Main Menu, press Preferences.

OSA 93

Setting Up the Instrument in Drift Mode

Defining Preferences

2. Select the General tab.

3. Define the general parameters as needed.

4. Press OK to save the changes and close the window, or press Cancel to

exit without saving.

Press Clear to clear all the changes made in the General tab.

94 FTB-5240S/S-P/BP

EXFO FTB-5240S, FTB-5240BP User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Certification Information

Models

Typical Applications

Optional Software Packages

Post-Processing Application

Conventions

2 Safety Information

3 Preparing Your OSA for a Test

Cleaning and Connecting Optical Fibers

Installing the EXFO Universal Interface (EUI)

Selecting a Test Mode

Switching Modes While a Trace is Open

Nulling Electrical Offsets

Performing User Calibration

Using the Autonaming Feature

Defining Preferences

Setting Up WDM Analysis Parameters

Setting Up Acquisition Parameters

Using the Commissioning Assistant

Defining Preferences