Agilent Technologies 3A User's Manual
Contents
1. E OD Figure 2 1 An Agilent 83493A installed in an Agilent 83480A mainframe 2 2 WARNING Operation Agilent 83491 2 3A Modules At a Glance Light energy can radiate from the front panel OUTPUT connectors on Agilent 83492A and 83493A modules The light emitted from these connectors is the slightly attenuated light that is input to the front panel INPUT connector Use with Agilent 71603B or 71612B Error Performance Analyzers The front panel Data and Clock outputs provide electrical recovered clock and regenerated data signals for simultaneous testing with other instruments such as the Agilent 71603B or 71612B error performance analyzers Multimode module and single mode reference receivers Agilent Technologies does not recommend using the Agilent 83492A multi mode module with single mode reference receivers such as the Agilent 83481A 83482A or 83485A B modules Connecting multimode to sin gle mode fibers causes large reflections and insertion loss because of the reduction of the optical fiber s core from 62 5 um to 9 um Single mode module and multimode reference receivers It is acceptable to use an Agilent 83493A single mode module with a multi mode reference receiver such as the Agilent 83486A module This is true pro vided that single mode fiber is connected to the Agilent 83493A module s front panel INPUT connector What you wo2. 1 3 Installation Installation AGILENT 83480A AGILENT Optical or Electrical 8349 1 2 3A Module Module settupb cdr Figure 1 2 Position of modules in the mainframe 3 Clean all optical interfaces as described in Cleaning Connections for Accurate Measurements on page 4 10 before making measurements 4 Perform the following steps if you re installing an Agilent 83492 3A module a Unscrew and remove the fiber optic adapter that is located on the optical module s front panel optical input connector b Connect the adapter that was removed in the previous step onto the Agilent 83492 3A module s front panel Input connector On Agilent 83492A module s the input connector used depends on the wavelength of the input signal Refer to To connect cables to an Agilent 83492A on page 1 7 5 Connect the supplied adapter cable as shown in Figure 1 3 WARNING Light energy can radiate from the front panel OUTPUT connectors on Agilent 83492A and 83493A modules The light emitted from these connectors is the slightly attenuated light that is input to the front panel INPUT connector 6 Turn on the Agilent 83480A and connect a modulated signal to the Agilent 83491 2 3A module s Input connector 1 4 CAUTION CAUTION Installation Installation AGILENT 83480A Adapter Cable settupa Figure 1 3 The adapter cable Agilent 83491A Modules Maximum safe signal input level is 5V The inp
3. Installation Agilent 83491 2 3A modules require that firmware revision A 06 25 or later be installed in the Agilent 83480A If you wish to install the module in an Agilent 54750A digitizing oscilloscope you must first install the Agilent 83480K communications firmware upgrade kit To check the Agilent 83480A s firmware revision code Press the Utility key and then the System config softkey The firmware revision number is listed under the Frame section of the display Fiber optic connectors are easily damaged when connected to dirty or damaged cables and accessories The Agilent 83492A and 83493A front panel input connectors are no exception When you use improper cleaning and handling techniques you risk expensive instrument repairs damaged cables and compromised measurements Before you connect any fiber optic cable to an Agilent 83492A or 83493A module refer to Cleaning Connections for Accurate Measurements on page 4 10 The circuits on electrical inputs and outputs can be damaged by electrostatic discharge ESD Therefore avoid applying static discharges to any front or rear panel electrical connector Before connecting any coaxial cable to a front panel connector momentarily short the center and outer conductors of the cable together Avoid touching the front panel connectors without first touching the frame of the instrument Be sure that the instrument is properly earth grounded to prevent buildup of static charge Re
4. CLOCK Auxiliary Output connector 2 5 compensation Agilent 54701A active probe 2 11 insertion loss 2 9 other devices 2 12 passive probe 2 11 compressed dust remover 4 17 connector care 4 10 cotton swabs 4 17 customer assistance iv D damaged shipment 1 3 DATA Auxiliary Output connector 2 5 data rate indicator lights 1 5 data rates 2 2 multiple of 2 8 declaration of conformity 3 8 dust caps 4 18 E electrostatic discharge 1 2 4 8 error messages 4 5 error performance analyzers use with 2 3 ESD reducing damage caused by ESD 4 9 static safe work station 4 9 extender cables 1 3 F fiber adapters 4 2 care of 1 2 connections on Agilent 83492A 1 7 multimode 2 2 reflections 2 6 single mode 2 2 single mode connections 2 6 fiber optics cleaning connections 4 10 connectors covering 4 21 firmware upgrade kit 1 2 version required 1 2 foam swabs 4 17 front panel 2 4 adapters 4 2 features 2 4 fuse values iii G GPIB programming 2 3 green light 1 5 Index 1 Index I IEC Publication 61010 1 iii input connector 4 10 Input connector 1 2 1 7 input connector 2 2 input signal maximum safe 1 5 insertion loss 2 3 2 6 compensation 2 9 instrument returning for service 4 20 ITU T G 957 2 5 M mainframe troubleshooting 4 3 maximum input level 1 5 O Output connector 2 5 P packaging for shipment 4 21 plug in module serial number 1 3 progra
5. out of alignment Also if unkeyed connectors are used the nickel silver can be pushed onto the glass surface Scratches fiber movement or glass contamina tion will cause loss of signal and increased reflections resulting in poor return loss Inspecting Connectors Because fiber optic connectors are susceptible to damage that is not immedi ately obvious to the naked eye poor measurements result without the user being aware Microscopic examination and return loss measurements are the best way to ensure good measurements Good cleaning practices can help ensure that optimum connector performance is maintained With glass to glass interfaces any degradation of a ferrule or the end of the fiber any stray particles or finger oil can have a significant effect on connector performance Where many repeat connections are required use of a connector saver or patch cable is recommended Figure 4 5 shows the end of a clean fiber optic cable The dark circle in the center of the micrograph is the fiber s 125 um core and cladding which carries the light The surrounding area is the soft nickel silver ferrule Figure 4 6 shows a dirty fiber end from neglect or perhaps improper cleaning Material is smeared and ground into the end of the fiber causing light scattering and poor reflection Not only is the precision polish lost but this action can grind off the glass face and destroy the connector Figure 4 7 shows physical damage to the glass f
6. Replacing a dam aged connector can cost thousands of dollars not to mention lost time This expense can be avoided by observing the simple precautions presented in this book This book also contains a brief list of tips for caring for electrical connec tors Choosing the Right Connector A critical but often overlooked factor in making a good lightwave measure ment is the selection of the fiber optic connector The differences in connec tor types are mainly in the mechanical assembly that holds the ferrule in position against another identical ferrule Connectors also vary in the polish curve and concentricity of the core within the cladding Mating one style of cable to another requires an adapter Agilent Technologies offers adapters for most instruments to allow testing with many different cables Figure 4 2 on page 4 11 shows the basic components of a typical connectors The system tolerance for reflection and insertion loss must be known when selecting a connector from the wide variety of currently available connectors Some items to consider when selecting a connector are How much insertion loss can be allowed Will the connector need to make multiple connections Some connectors are better than others and some are very poor for making repeated connections What is the reflection tolerance Can the system take reflection degradation Is an instrument grade connector with a precision core alignment required Is repeatabilit
7. Technologies Service Offices Agilent Technologies Service Offices Before returning an instrument for service call the Agilent Technologies Instrument Support Center at 800 403 0801 visit the Test and Measurement Web Sites by Country page at http www tm agilent com tmo country English index html or call one of the numbers listed below Agilent Technologies Service Numbers Austria 01 25125 7171 Belgium 32 2 778 37 71 Brazil 11 7297 8600 China 86 10 6261 3819 Denmark 45 99 12 88 Finland 358 10 855 2360 France 01 69 82 66 66 Germany 0180 524 6330 India 080 34 35788 Italy 39 02 9212 2701 Ireland 01 615 8222 Japan 81 426 56 7832 Korea 82 2 3770 0419 Mexico 5 258 4826 Netherlands 020 547 6463 Norway 220310759 Russia 7 095 797 3930 Spain 34 91 631 1213 Sweden 08 5064 8700 Switzerland 01 735 7200 United Kingdom United States Canada 01 344 366666 800 403 0801 4 23 Index A adapter cable 1 3 1 4 Agilent 54701A active probe 2 11 Agilent 83492A connections 1 7 maximum input level 1 5 Agilent offices 4 23 B Bellcore GR 253 CORE 2 5 block diagram 2 7 bypass mode 2 4 2 5 C cabinet cleaning iii calibration cycle 3 2 care of cabinet iii care of fiber optics 1 2 channel key 1 2 setup 1 2 Channel key 2 3 characteristics defined 3 2 classification product iii cleaning adapters 4 19 cabinet iii fiber optic connections 4 10 4 18 non lensed connectors 4 18
8. before damage characteristic DATA and CLOCK output amplitude all rates characteristic INPUT electrical return loss DC through 1250 MHz characteristic 1250 MHz through 2500 MHz characteristic DATA and CLOCK electrical return loss 50 MHz through 2000 MHz characteristic 2000 MHz through 2500 MHz characteristic Source extinction ratio gt 8 2 dB when measured per TIA EIA OFSTP 4A Operating power level applies over temperature range 25 C 5 Better than 10 BER when tested with PRBS 221 pattern Measured on an oscilloscope eye diagram with PRBS 27 1 test pattern ao oo 0 1 0 1 0 1 0 1 0 1 0 1 0 1 50 Mb s to 2500 Mb s 10 dBm to 3 dBm 10 dBm to 3 dBm lt 7 dB 0 0125 Ul 1W peak 0 5Vp p gt 20 dB 2 15dB 2 10dB gt 60dB 3 3 Specifications and Regulatory Information Agilent 83492A Specifications Agilent 83492A Specifications Table 3 2 Agilent 83492A Specifications 1 of 2 Wavelength range characteristic Optical INPUT and OUTPUT fiber characteristic Optical insertion loss through path 750 nm to 860 nm 1000 nm to 1600 nm Optical return loss Clock recovery rates NRZ coding 155 52 Mb s 622 08 Mb s 1062 50 Mb s 1250 Mb s 2125 00 Mb s 2488 32 Mb s 2500 00 Mb s Data triggering characteristic Opera ing input power level 750 nm to 860 nm Triggering operation all rates 0 1 BER all rates 1000 nm
9. matching gel or oil must be used apply it to a freshly cleaned connector make the measurement and then immediately clean it off Never use a gel for longer term connections and never use it to improve a damaged connector The gel can mask the extent of damage and continued use of a damaged fiber can transfer damage to the instrument When inserting a fiber optic cable into a connector gently insert it in as straight a line as possible Tipping and inserting at an angle can scrape material off the inside of the connector or even break the inside sleeve of connectors made with ceramic material When inserting a fiber optic connector into a connector make sure that the fi ber end does not touch the outside of the mating connector or adapter Avoid over tightening connections Unlike common electrical connections tighter is not better The purpose of the connector is to bring two fiber ends together Once they touch tightening only causes a greater force to be applied to the delicate fibers With connec tors that have a convex fiber end the end can be pushed off axis resulting in misalignment and excessive return loss Many measurements are actually improved by backing off the connector pressure Also if a piece of grit does happen to get by the cleaning procedure the tighter connection is more likely to damage the glass Tighten the connectors just until the two fibers touch 4 15 Reference Cleaning Connections for Accurate Meas
10. rate green data rate key light is selected is selected 83491A ELECTRICAL 2500 Mb s OCK RECOVER 155 Mb s 2488 Mb s 1062 Mb s O 1250 Mb s m 622 Mb s 2125 Mb s O 2500 Mb s O Clock tls Auxiliary Outputs ay Figure 1 4 Front panel lights 9 Confirm that the Unlocked light is off 10 Observe the Clock and Data outputs on an oscilloscope Waveforms should be present The instrument is now ready for you to begin making measurements 1 6 Installation Installation To connect cables to an Agilent 83492A On Agilent 83492 A modules the front panel fiber optic connectors reverse input and output roles depending on the wavelength of the signal Signals in the 750 nm to 860 nm wavelength range are input to the left connector and output from the right connector Signals in the 1000 nm to 1600 nm wave length range are input to the right connector and output from the left connec tor Input wavelength range 750 nm to 860 nm 83492A 2500 Mb s MULTIMODE CLOCK RECOVERY MODULE SELECT 185 Nos 2488 Nis DO pg vers ome O Tiger OG ber ntaa 21 Nos O 2500 neve OD Data Unlocked Clock U auna outputs Optical 780 50 nm 1310 1550 nm 62 729 um 10 Mw Max 750 nm to 860 nm Figure 1 5 83487A OPTICAL ELECTRICAL MODULE 10631129 Mbis SETUP OPTICAL CHANNEL Input wavelength range 1000 nm to 1600 nm 83492A 200Mmbs MULIMODE CLOCK RECOVERY MODULE SELECT 1581 282
11. to 1600 nm Outpu Triggering operation all rates 0 19 BER all rates jitter all rates 9 Maximum continuous optical power before damage characteristic DATA and CLOCK output amplitude all rates characteristic 750 nm to 860 nm and 1000 nm to 1600 nm 62 5 125 multimode lt 5 0 dB lt 5 0 dB 2 28 dB 0 1 0 1 0 1 0 1 0 1 0 1 0 1 50 Mb s to 2500 Mb s 10 dBm to 3 dBm 10 dBm to 3 dBm 13 dBm to 3 dBm 13 dBm to 3 dBm 0 0125 Ul 10 mW peak 0 5Vp p 3 4 Specifications and Regulatory Information Agilent 83492A Specifications Table 3 2 Agilent 83492A Specifications 2 of 2 DATA and CLOCK electrical return loss 50 MHz through 2000 MHz characteristic gt 10dB 2000 MHz through 2500 MHz characteristic gt 6dB a Minimum loss in 850 nm window b Single mode backreflection tested with FC PC adapter and single mode fiber Optical output terminated with gt 33 dB return loss Return loss with fully filled 62 5 Lim core multimode fiber may be slightly lower Source extinction ratio gt 8 2 dB when measured per TIA EIA OFSTP 4A Operating power level applies over temperature range 25 C 5 Better than 10 BER when tested with PRBS 221 pattern Better than 10 BER when tested with PRBS 23 1 pattern Measured on an oscilloscope eye diagram with PRBS 2 1 test pattern Q 0 0 3 5 Specifications and Regulatory Information Agilent 83493A Sp
12. types to mate with this precision connector See Figure 4 3 Reference Cleaning Connections for Accurate Measurements Figure 4 3 Universal adapters to Diamond HMS 10 The HMS 10 encases the fiber within a soft nickel silver Cu Ni Zn center which is surrounded by a tough tungsten carbide casing as shown in Figure 4 4 Staking Groove Fixing oper Secondary Staking Active Centering Tungsten Carbide Nickel Silver CuNifZn Hard Case Soft center F 125 um Fiber Centered to abou 02 microns Figure 4 4 Cross section of the Diamond HMS 10 connector The nickel silver allows an active centering process that permits the glass fiber to be moved to the desired position This process first stakes the soft nickel silver to fix the fiber in a near center location then uses a post active staking to shift the fiber into the desired position within 0 2 um This process plus the keyed axis allows very precise core to core alignments This connector is found on most Agilent Technologies lightwave instruments 4 12 Reference Cleaning Connections for Accurate Measurements The soft core while allowing precise centering is also the chief liability of the connector The soft material is easily damaged Care must be taken to mini mize excessive scratching and wear While minor wear is not a problem if the glass face is not affected scratches or grit can cause the glass fiber to move
13. 3491 2 3A Operating Specifications Use Temperature Operating Non operating Altitude Operating Non operating Humidity Operating Non operating Net weight Shipping weight Power Requirements Indoor 0 C to 55 C 40 C to 70 C 4600 m 15 000 ft 15 300 m 50 000 ft up to 90 relative humidity at lt 35 C up to 90 relative humidity at lt 35 C approximately 1 2 kg 2 6 Ib approximately 2 1 kg 4 6 Ib Supplied by mainframe 3 7 Specifications and Regulatory Information Declaration of Conformity Declaration of Conformity DECLARATION OF CONFORMITY According to ISO IEC Guide 22 and EN 45014 Hewlett Packard Co Manufacturer s Name Manufacturer s Address 1400 Fountaingrove Parkway Santa Rosa CA 95403 1799 USA Declares that the product Product Name Clock Recovery Trigger Module Model Number HP 83491A HP 83492A HP 83493A Product Options This declaration covers all options of the above product Conforms to the following product specifications Safety IEC 61010 1 1990 EN 61010 1 1993 CAN CSA C22 2 No 1010 1 92 EMC CISPR 11 1990 EN 55011 1991 Group 1 Class A IEC 801 2 1984 EN 50082 1 1992 4 KV CD 8 kV AD IEC 801 3 1984 EN 50082 1 1992 3 V m 27 500 MHz IEC 801 4 1988 EN 50082 1 1992 0 5 KV sig lines 1 kV power lines Supplementary Information The product herewith compl
14. Agilent 83491 2 3A Clock Recovery Modules User s Guide egg Agilent Technologies O Copyright 2000 Agilent Technologies All Rights Reserved Repro duction adaptation or trans lation without prior written permission is prohibited except as allowed under copy right laws Agilent Part No 83491 90013 Printed in USA February 2000 Agilent Technologies Lightwave Division 1400 Fountaingrove Parkway Santa Rosa CA 95408 1799 USA 707 577 1400 Notice The information contained in this document is subject to change without notice Com panies names and data used in examples herein are ficti tious unless otherwise noted Agilent Technologies makes no warranty of any kind with regard to this material includ ing but not limited to the implied warranties of mer chantability and fitness for a particular purpose Agilent Technologies shall not be lia ble for errors contained herein or for incidental or conse quential damages in connec tion with the furnishing performance or use of this material Restricted Rights Legend Use duplication or disclo sure by the U S Government is subject to restrictions as set forth in subparagraph c 1 Gi of the Rights in Technical Data and Computer Software clause at DFARS 252 227 7013 for DOD agencies and sub paragraphs c 1 and c 2 of the Commercial Computer Software Restricted Rights clause at FAR 52 227 19 for other agencies Warranty This A
15. an approximately 23 dBm CLOCK connector This connector provides the recovered clock signal You can use this signal to measure jitter transfer because this output can track and fol low input data with very fast jitter it has a wide bandwidth jitter transfer func tion when compared to the recovered clock signal which is routed through a rear panel connector to the mainframe for triggering Note that the CLOCK Aux iliary Output remains synchronized to input signals several dB below the onset of errors at the DATA Auxiliary Output The input connectors pass the digitally modulated signal to the receiver mod ule The input signal slightly attenuated and available at the OUTPUT connec tor is connected to the input of any of the Agilent 83481 2 3 4 5 6 or 7 modules The connectors on optical modules include adapters which can eas ily be changed to match the type of connectors that are used on your fiber optic cables Refer to Front Panel Optical Adapters on page 4 2 for a description of the available adapters 2 5 Recovered Clock Operation Front Panel Features Multimode and single mode connections Agilent 83492A modules use multimode fiber Connecting the output to the Optical INPUT connector on Agilent 83481 2 5 single mode modules results in large reflections and insertion loss Agilent 83493A modules use 9 125 um single mode fiber Connecting multimode fiber to the Optical Input connector results in large reflect
16. arton They may also cause instrument damage by generating static electricity Pack the instrument in the original shipping containers Original materials are available through any Agilent Technologies office Or use the following guidelines e Wrap the instrument in antistatic plastic to reduce the possibility of damage caused by electrostatic discharge e For instruments weighing less than 54 kg 120 Ib use a double walled cor rugated cardboard carton of 159 kg 850 Ib test strength e The carton must be large enough to allow approximately 7 cm 3 inches on all sides of the instrument for packing material and strong enough to accom modate the weight of the instrument e Surround the equipment with approximately 7 cm 8 inches of packing ma terial to protect the instrument and prevent it from moving in the carton If packing foam is not available the best alternative is S D 240 Air Cap from 4 21 Reference Returning the Instrument for Service Sealed Air Corporation Commerce California 90001 Air Cap looks like a plastic sheet filled with air bubbles Use the pink antistatic Air Cap to reduce static electricity Wrapping the instrument several times in this ma terial will protect the instrument and prevent it from moving in the carton 4 Seal the carton with strong nylon adhesive tape 5 Mark the carton FRAGILE HANDLE WITH CARE 6 Retain copies of all shipping papers 4 22 Reference Agilent
17. cratches and wear if the glass has maintained its polished smoothness the connector can still provide a good low level return loss con nection If you test your cables and accessories for insertion loss and return loss upon receipt and retain the measured data for comparison you will be able to tell in the future if any degradation has occurred Typical values are less than 0 5 dB of loss and sometimes as little as 0 1 dB of loss with high performance con nectors Return loss is a measure of reflection the less reflection the better the larger the return loss the smaller the reflection The best physically contacting connectors have return losses better than 50 dB although 30 to 40 dB is more common 4 16 WARNING CAUTION Reference Cleaning Connections for Accurate Measurements Visual inspection of fiber ends Visual inspection of fiber ends can be helpful Contamination or imperfections on the cable end face can be detected as well as cracks or chips in the fiber itself Use a microscope 100X to 200X magnification to inspect the entire end face for contamination raised metal or dents in the metal as well as any other imperfections Inspect the fiber for cracks and chips Visible imperfec tions not touching the fiber core may not affect performance unless the imperfections keep the fibers from contacting Always remove both ends of fiber optic cables from any instrument system or device before visually
18. cteristics Calibration cycle Specifications and Regulatory Information Specifications and Regulatory Information Specifications and Regulatory Information This chapter lists specifications and characteristics of the Agilent 83491 2 3A Specifications apply over the temperature range 15 C to 35 C unless oth erwise noted after the instrument s temperature has been stabilized after 60 minutes of continuous operation Specifications described warranted performance Characteristics provide useful nonwarranted information about the func tions and performance of the instrument Characteristics are printed in italics Agilent Technologies warrants instrument specifications over the recom mended calibration interval To maintain specifications periodic recalibrations are necessary We recommend that the Agilent 83491 2 3A be calibrated at an Agilent Technologies service facility every 24 months 3 2 Specifications and Regulatory Information Agilent 83491A Specifications Agilent 83491A Specifications Table 3 1 Agilent 83491A Specifications Clock recovery rates NRZ coding 155 52 Mb s 622 08 Mb s 1062 50 Mb s 1250 Mb s 2125 00 Mb s 2488 32 Mb s 2500 00 Mb s Data triggering characteristic Operating input power level 2 Triggering operation all rates 10 BER all rates Insertion loss through path DC through 2500 MHz Output jitter all rates Maximum continuous electrical power
19. curate amplitude mea surements at the input to the clock recovery module Disconnect the cable from the clock recovery module s Input connector Measure the signal using a power meter You can use either the Agilent 83480A s built in power meter or an external power meter 3 Reconnect the cable to the clock recovery module Disconnect the cable from the reference receiver module s input connector 5 Measure the signal using a power meter You can use either the Agilent 83480A s built in power meter or an external power meter Subtract the two measurements to determine the insertion loss of the module On the reference receiver module press the front panel channel SETUP key 8 Press External scale and set the Atten units to decibel Press Attenuation and enter the value calculated in Step 6 2 9 Operation Using Probes with an Agilent 83491A Using Probes with an Agilent 83491A You can use external passive and active probes with the Agilent 83491A elec trical clock recovery module The procedures in this section generate vertical scale factors These factors are applied to the calibration of the reference receiver module s electrical channel When selecting a probe keep in mind that the input impedance of the Agilent 83491A is 50Q If the probe being calibrated has an attenuation factor that allows the instru ment to adjust the gain to produce even steps in the vertical scale factors the instrume
20. e positions of the instru ment power line switch The CE mark is a reg istered trademark of the European Commu nity The CSA mark is a reg istered trademark of the Canadian Stan dards Association The C Tick mark is a registered trademark of the Australian Spec trum Management Agency This text denotes the instrument is an Industrial Scientific and Medical Group 1 Class A product ISM1 A Typographical Conven tions The following conventions are used in this book Key type for keys or text located on the keyboard or instrument Softkey type for key names that are displayed on the instru ment s screen Display type for words or characters displayed on the computer s screen or instru ment s display User type for words or charac ters that you type or enter Emphasis type for words or characters that emphasize some point or that are used as place holders for text that you type il WARNING WARNING WARNING WARNING WARNING WARNING General Safety Considerations General Safety Considerations This product has been designed and tested in accordance with IEC Publica tion 61010 1 Safety Requirements for Electrical Equipment for Measurement Control and Laboratory Use and has been supplied in a safe condition The instruction documentation contains information and warnings that must be followed by the user to ensure safe op
21. e instructions The Agilent 83480A Agilent 54750A mainframes do not accept plug in mod ules designed for use with the Agilent 54710A 54720A Plug in is not supported System firmware upgrade is needed The mainframe may need to have the latest operating system firmware installed Options 001 and 002 provide this firmware on a 3 5 inch diskette To load the new firmware follow the instructions provided with the diskette If you do not have the optional diskette contact your local Agilent Technologies service office 4 7 Reference Electrostatic Discharge Information Electrostatic Discharge Information Electrostatic discharge ESD can damage or destroy electronic components All work on electronic assemblies should be performed at a static safe work station The following figure shows an example of a static safe work station using two types of ESD protection e Conductive table mat and wrist strap combination e Conductive floor mat and heel strap combination IT IE Building Ground 4 NG 1 Meg Ohm Resistor ay s Figure 4 1 Static safe work station 4 8 WARNING Reference Electrostatic Discharge Information Both types when used together provide a significant level of ESD protection Of the two only the table mat and wrist strap combination provides adequate ESD protection when used alone To ensure user safety the static safe accessories must provide at least 1 MQ of iso
22. e signal Green and red data rate lights The data rate indicator lights change color between red and green to show which data rate is selected A red light does not indicate a problem A red light shows that the adja cent red data rate label is selected A green light shows that the adjacent green data rate label is selected Repeatedly pressing the SELEGT key cycles through the selections in one color before switching to the opposite color On Agilent 83491A modules for example the first selection cycle shows 155 Mb s selected The second section cycle shows 1062 Mb s selected e Ifthe UNLOCKED light is on clock recovery cannot be established on the signal e Avoid selecting a data rate that is a multiple of the input signal For example don t select a 622 Mb s data rate if the signal is really at 155 Mb s e Ifyou cannot get the clock recovery module to lock on the signal make sure that you have selected the correct data rate and that the Agilent 83480A or Agilent 54750A mainframe trigger level is adjusted appropriately e Signals displayed using a data trigger are less reliable than using a recovered clock Signals triggered on data can also vary depending upon the trigger level 2 8 Operation To Compensate for Module Insertion Loss To Compensate for Module Insertion Loss The following steps allow you to enter an offset to compensate for the inser tion loss of the clock recovery module This provides ac
23. ecifically dis claims the implied warranties of merchantability and fitness for a particular purpose Exclusive Remedies The remedies provided herein are buyer s sole and exclusive remedies Agilent Technolo gies shall not be liable for any direct indirect special inci dental or consequential dam ages whether based on contract tort or any other legal theory Safety Symbols CAUTION The caution sign denotes a hazard It calls attention to a procedure which if not cor rectly performed or adhered to could result in damage to or destruction of the product Do not proceed beyond a cau tion sign until the indicated conditions are fully under stood and met WARNING The warning sign denotes a hazard It calls attention to a procedure which if not cor rectly performed or adhered to could result in injury or loss of life Do not proceed beyond a warning sign until the indicated conditions are fully understood and met The instruction man A ual symbol The prod uct is marked with this warning symbol when it is necessary for the user to refer to the instructions in the manual The laser radiation symbol This warning symbol is marked on products which have a laser output The AC symbol is used to indicate the required nature of the line module input power The ON symbols are used to mark the posi tions of the instrument power line switch o O The OFF symbols are used to mark th
24. ecifications Agilent 83493A Specifications Table 3 3 Agilent 83493A Specifications Wavelength range characteristic 1000 nm to 1600 nm Optical INPUT fiber characteristic 9 125 single mode Optical insertion loss through path lt 1 5dB Optical return loss gt 28 dB Clock recovery rates NRZ coding 155 52 Mb s 0 1 622 08 Mb s 0 1 1250 Mb s 0 1 2488 32 Mb s 0 1 2500 00 Mb s 0 1 Data triggering characteristic 50 Mb s to 2500 Mb s Operating input power level Triggering operation all rates 20 dBm to 3 dBm 101 BER all rates 17 dBm to 3 dBm Output jitter all rates 0 0125 Ul Maximum continuous optical power before damage characteristic 10 mW peak DATA and CLOCK output amplitude all rates characteristic 0 5Vp p DATA and CLOCK output electrical return loss 50 MHz through 2000 MHz characteristic gt 10dB 2000 MHz through 2500 MHz characteristic gt 6dB Tested with FC PC adapter Optical output terminated without gt 33 dB return loss Source extinction ratio gt 8 2 dB when measured per TIA EIA OFSTP 4A Operating power level applies over temperature range 25 C 5 Better than 10 BER when tested with PRBS 221 pattern Measured on an oscilloscope eye diagram with PRBS 21 test pattern ao rcr oo 3 6 Specifications and Regulatory Information Agilent 83491 2 3A Operating Specifications Agilent 83491 2 3A Operating Specifications Table 3 4 Agilent 8
25. eration and to maintain the product in safe condition Light energy can radiate from the front panel OUTPUT connectors on Agilent 83492A and 83493A modules The light emitted from these connectors is the slightly attenuated light that is input to the front panel INPUT connector If this instrument is not used as specified the protection provided by the equipment could be impaired This instrument must be used in a normal condition in which all means for protection are intact only To prevent electrical shock disconnect the Agilent 83491 2 3A from mains before cleaning Use a dry cloth or one slightly dampened with water to clean the external case parts Do not attempt to clean internally This is a Safety Class 1 product provided with a protective earthing ground incorporated in the power cord The mains plug shall only be inserted in a socket outlet provided with a protective earth contact Any interruption of the protective conductor inside or outside of the product is likely to make the product dangerous Intentional interruption is prohibited No operator serviceable parts inside Refer servicing to qualified personnel To prevent electrical shock do not remove covers For continued protection against fire hazard replace line fuse only with same type and ratings type T 0 315A 250V for 100 120V operation and 0 16A 250V for 220 240V operation The use of other fuses or materials is prohibited Verify that the value of the l
26. failure and error messages along with the instrument being returned Preparing the instrument for shipping Write a complete description of the failure and attach it to the instrument Include any specific performance details related to the problem The following 4 20 CAUTION CAUTION Reference Returning the Instrument for Service information should be returned with the instrument e Type of service required e Date instrument was returned for repair e Description of the problem e Whether problem is constant or intermittent e Whether instrument is temperature sensitive e Whether instrument is vibration sensitive e Instrument settings required to reproduce the problem e Performance data Company name and return address Name and phone number of technical contact person Model number of returned instrument Full serial number of returned instrument List of any accessories returned with instrument Cover all front or rear panel connectors that were originally covered when you first received the instrument Cover electrical connectors to protect sensitive components from electrostatic damage Cover optical connectors to protect them from damage due to physical contact or dust Instrument damage can result from using packaging materials other than the original materials Never use styrene pellets as packaging material They do not adequately cushion the instrument or prevent it from shifting in the c
27. fer to Electrostatic Discharge Information on page 4 8 1 2 0 0 0 o Installation Installation To install the module Verify that all system components ordered have arrived by comparing the shipping forms to the original purchase order Inspect all shipping containers The shipment includes An Agilent 83491 2 3A Clock Recovery Module Fiber optic adapter cable Agilent 83492 3A module only Two RF adapter cables Agilent 88491A module only Agilent 83491 2 3A User s Guide this book If your shipment is damaged or incomplete save the packing materials and notify both the shipping carrier and the nearest Agilent Technologies service office Agilent Technologies will arrange for repair or replacement of damaged or incomplete shipments without waiting for a settlement from the transporta tion company Notify the Agilent Technologies customer engineer of any prob lems Make sure that the serial number listed on the module s rear panel label matches the serial number listed on the shipping document SER US39200000 Agilent Figure 1 1 Serial number label Install the Agilent 83491 2 3A module into the Agilent 83480A mainframe s left slot Finger tighten the knurled screw on the front panel of the plug in module to ensure that the module is securely seated in the mainframe Note Installing the module into the left slot ensures that the supplied adapter cable will fit See Figure 1 2
28. gilent Technologies instrument product is war ranted against defects in material and workmanship for a period of one year from date of shipment During the war ranty period Agilent Technol ogies will at its option either repair or replace products which prove to be defective For warranty service or repair this product must be returned to a service facility desig nated by Agilent Technolo gies Buyer shall prepay shipping charges to Agilent Technologies and Agilent Technologies shall pay ship ping charges to return the product to Buyer However Buyer shall pay all shipping charges duties and taxes for products returned to Agilent Technologies from another country Agilent Technologies war rants that its software and firmware designated by Agi lent Technologies for use with an instrument will execute its programming instructions when properly installed on that instrument Agilent Tech nologies does not warrant that the operation of the instru ment or software or firmware will be uninterrupted or error free Limitation of Warranty The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfac ing unauthorized modifica tion or misuse operation outside of the environmental specifications for the product or improper site preparation or maintenance No other warranty is expressed or implied Agilent Technologies sp
29. he plug in module is firmly seated in the mainframe slot Verify the knurled screws at the bottom of the plug in module are finger tight Install the plug in in a different slot in the mainframe Communications failure exists at slot Service is required An illegal hardware state is detected at the mainframe to plug in module interface of the specified slot If the slot is empty there is a mainframe hardware problem Refer to the Agilent 83480A Agilent 54750A Service Guide If a plug in is installed in the slot there is a plug in module hardware problem Return the plug in module to a qualified service department ID error occurred in plug in Service is required The information read from the memory of the plug in module does not match the hardware in the plug in module This can be caused by a communication problem between the mainframe and the plug in module Make sure there is good connection between the mainframe and the plug in Remove and re install the plug in module Verify the plug in module is firmly seated in the mainframe slot Verify the knurled screws at the bottom of the plug in module are finger tight The standard Agilent 54750A mainframe does not accept the Agilent 83491 2 3A module To use the module a firmware upgrade must first be installed Or 4 6 Reference Plug in is not supported System firmware upgrade is needed der the Agilent 83480K communications firmware kit and install according to th
30. iber end caused by either repeated connections made without removing loose particles or using improper cleaning tools When severe the damage of one connector end can be transferred to another good connector endface that comes in contact with the damaged one Periodic checks of fiber ends and replacing connecting cables after many connections is a wise practice The cure for these problems is disciplined connector care as described in the following list and in Cleaning Connectors on page 4 17 4 13 Reference Cleaning Connections for Accurate Measurements Use the following guidelines to achieve the best possible performance when making measurements on a fiber optic system e Never use metal or sharp objects to clean a connector and never scrape the connector e Avoid matching gel and oils p Figure 4 5 Clean problem free fiber end and ferrule z ra 5 a kt EE Figure 4 6 Dirty fiber end and ferrule from poor cleaning 4 14 Reference Cleaning Connections for Accurate Measurements Figure 4 7 Damage from improper cleaning While these often work well on first insertion they are great dirt magnets The oil or gel grabs and holds grit that is then ground into the end of the fiber Also some early gels were designed for use with the FC non contacting con nectors using small glass spheres When used with contacting connectors these glass balls can scratch and pit the fiber If an index
31. ies with the requirements of the Low Voltage Directive 73 23 EEC and the EMC Directive 89 336 EEC and carries the CE marking accordingly Santa Rosa CA USA June 10 1999 pie Greg Pfeiffer Quality Engineering Manager European Contact Your local Hewlett Packard Sales and Service Office or Hewlett Packard GmbH Department HQ TRE Herreneberger Strasse 130 D71034 Boblingen Germany FAX 49 7031 14 3143 3 8 Front Panel Optical Adapters 4 2 In Case of Difficulty 4 3 Error Messages 4 5 Electrostatic Discharge Information 4 8 Cleaning Connections for Accurate Measurements 4 10 Returning the Instrument for Service 4 20 Agilent Technologies Service Offices 4 23 Reference Reference Front Panel Optical Adapters Front Panel Optical Adapters Front Panel Fiber Optic Description Agilent Part Number Adapter din Diamond HMS 10 81000A 8 FC PC 81000FI IE D4 810006 4 sc 81000KI iZ DIN 810008I og ST 81000VI n Biconic 81000WI Dust Covers FC connector 1005 0594 Diamond HMS 10 connector 1005 0593 DIN connector 1005 0595 ST connector 1005 0596 SC connector 1005 0597 a The FC PC adapter is the standard adapter supplied with the instrument 4 2 w a w ar aoa Od 0 0 Reference In Case of Difficulty In Case of Difficulty This section provides a list of suggestions for you to follow if the plug in mod ule fails to operate A list of messages that may be displa
32. indicator Auxiliary outputs Input and Output connectors Operation Front Panel Features Green and red data rate lights The data rate indicator lights change color between red and green to show which data rate is selected A red light does not indicate a problem A red light shows that the adja cent red data rate label is selected A green light shows that the adjacent green data rate label is selected Repeatedly pressing the SELEGT key cycles through the selections in one color before switching to the opposite color On Agilent 83491A modules for example the first selection cycle shows 155 Mb s selected The second section cycle shows 1062 Mb s selected This light shows when clock recovery cannot be established on the signal If a clock rate is selected the trigger output to the mainframe is disabled to pre vent free run triggering However in bypass mode Trigger On Data selected triggering is not disabled When the UNLOCKED light is on you can establish a trigger on the data input to the reference receiver DATA connector This connector provides a fully regenerated version of the input signal It is intended for monitoring purposes only and not for rigorous eye mask compliance testing The frequency response does not conform to the requirements for eye mask testing as described in ITU T G 957 and Bellcore GR 253 CORE On Agilent 83492A and 83493A modules this port is ampli tude stabilized for input signals greater th
33. ine voltage fuse is correct e For 100 120V operation use an IEC 127 5x20 mm 0 315 A 250 V Agilent iii CAUTION CAUTION CAUTION CAUTION CAUTION CAUTION CAUTION General Safety Considerations Technologies part number 2110 0449 e For 220 240V operation use an IEC 127 5x20 mm 0 16 A 250 V Agilent Technologies part number 2110 0448 Before switching on this instrument make sure that the line voltage selector switch is set to the line voltage of the power supply and the correct fuse is installed Assure the supply voltage is in the specified range This product is designed for use in Installation Category II and Pollution Degree 2 per IEC 1010 and 664 respectively VENTILATION REQUIREMENTS When installing the product in a cabinet the convection into and out of the product must not be restricted The ambient temperature outside the cabinet must be less than the maximum operating temperature of the product by 4 C for every 100 watts dissipated in the cabinet If the total power dissipated in the cabinet is greater than 800 watts then forced convection must be used Always use the three prong ac power cord supplied with this instrument Failure to ensure adequate earth grounding by not using this cord may cause instrument damage Do not connect ac power until you have verified the line voltage is correct Damage to the equipment could result This instrument has autorang
34. ing line voltage input Be sure the supply voltage is within the specified range Electrostatic discharge ESD on or near input connectors can damage circuits inside the instrument Repair of damage due to misuse is not covered under warranty Before connecting any cable to the electrical input momentarily short the center and outer conductors of the cable together Personnel should be properly grounded and should touch the frame of the instrument before touching any connector iv Contents General Safety Considerations iii Installation Installation 1 2 Operation Agilent 83491 2 3A Modules At a Glance 2 2 Front Panel Features 2 4 Block Diagrams 2 7 To Display a Signal 2 8 To Compensate for Module Insertion Loss 2 9 Using Probes with an Agilent 83491A 2 10 Specifications and Regulatory Information Agilent 83491A Specifications 3 3 Agilent 83492A Specifications 3 4 Agilent 83493A Specifications 3 6 Agilent 83491 2 3A Operating Specifications 3 7 Declaration of Conformity 3 8 Reference Front Panel Optical Adapters 4 2 In Case of Difficulty 4 3 Error Messages 4 5 Electrostatic Discharge Information 4 8 Cleaning Connections for Accurate Measurements 4 10 Returning the Instrument for Service 4 20 Agilent Technologies Service Offices 4 23 Contents 1 To install the module 1 3 To connect cables to an Agilent 83492A 1 7 Installation CAUTION CAUTION Installation Installation
35. inspecting the fiber ends Disable all optical sources before disconnecting fiber optic cables Failure to do so may result in permanent injury to your eyes Cleaning Connectors The procedures in this section provide the proper steps for cleaning fiber optic cables and Agilent Technologies universal adapters The initial cleaning using the alcohol as a solvent gently removes any grit and oil If a caked on layer of material is still present this can happen if the beryllium copper sides of the ferrule retainer get scraped and deposited on the end of the fiber during insertion of the cable a second cleaning should be performed It is not uncommon for a cable or connector to require more than one cleaning Agilent Technologies strongly recommends that index matching compounds not be applied to their instruments and accessories Some compounds such as gels may be difficult to remove and can contain damaging particulates If you think the use of such compounds is necessary refer to the compound manufacturer for information on application and cleaning procedures Table 4 2 Cleaning Accessories Item Agilent Part Number Any commercially available denatured alcohol Cotton swabs 8520 0023 Small foam swabs 9300 1223 Compressed dust remover non residue 8500 5262 4 17 CAUTION Reference Cleaning Connections for Accurate Measurements Table 4 3 Dust Caps Provided with Lightwave Instruments Item Agilent Par
36. ions and insertion loss The recovered clock signal is routed directly to the Agilent 83480A mainframe through the module s rear panel This output has a lower jitter modulation bandwidth than the front panel CLOCK Auxiliary Output Because of the reduced jitter modulation bandwidth on the mainframe trigger signal a more complete view of the jitter on the waveform data is obtained 2 6 Operation Block Diagrams Block Diagrams Po gas x lt Clock Data i 2500 MH2 Receiver i gt Trigger Output to Output TRIGGER on i Mainframe 7dB DATA Path i i DATA i Trigger I CLOCK Select h i Control Panel Rear Panel 9ibd Figure 2 3 Agilent 83491A Block Diagram INPUT 50 MHz 2500 MHz modulation a x lt Clock Data i Receiver i a gt rigger Output to i s Output TRIGGER on i Mainframe See Note DATA Path DATA i Trigger CLOCK Select i i i Mainframe Front Microcontroller gt Control Panel Note i AGILENT 83492A 5 dB Rear AGILENT 83493A 2 dB Panel 93bd Figure 2 4 Agilent 83492A and 83493A Block Diagram 2 7 Operation To Display a Signal To Display a Signal Install the module as described in To install the module on page 1 3 Be sure to connect all of the cables as described in the procedure Repeatedly press the SELECT key on the clock recovery module until the front panel light indicates the proper data rate of th
37. lation from ground Refer to Table 4 1 for information on ordering static safe accessories These techniques for a static safe work station should not be used when working on circuitry with a voltage potential greater than 500 volts Reducing ESD Damage The following suggestions may help reduce ESD damage that occurs during testing and servicing operations Personnel should be grounded with a resistor isolated wrist strap before re moving any assembly from the unit Be sure all instruments are properly earth grounded to prevent a buildup of static charge Table 4 1 Static Safe Accessories Agilent Part ae Number Description 9300 0797 Set includes 3M static control mat 0 6 m X 1 2 m 2 ftx 4 ft and 4 6 cm 15 ft ground wire The wrist strap and wrist strap cord are not included They must be ordered separately 9300 0980 Wrist strap cord 1 5 m 5 ft 9300 1383 Wrist strap color black stainless steel without cord has four adjustable links and a 7 mm post type connection 9300 1169 ESD heel strap reusable 6 to 12 months 4 9 Reference Cleaning Connections for Accurate Measurements Cleaning Connections for Accurate Measurements Today advances in measurement capabilities make connectors and connec tion techniques more important than ever Damage to the connectors on cali bration and verification devices test ports cables and other devices can degrade measurement accuracy and damage instruments
38. mming 2 3 R red light 1 5 regulatory information 3 2 responsivity testing 1 4 returning for service 4 20 S safety iii laser classification iii safety information iv 1 3 2 3 sales and service offices 4 23 SELECT key 1 5 2 4 serial number 1 3 service 4 20 returning for 4 20 sales and service offices 4 23 shipping procedure 4 20 single mode fiber 2 6 specifications 3 2 Agilent 83491A 3 3 Agilent 83492A 3 4 Agilent 83493A 3 6 defined 3 2 operating 3 7 temperature range 3 2 swabs 4 17 T technical assistance iv testing responsivity 1 4 trigger bypass mode 2 4 2 5 Trigger On Data light 2 4 troubleshooting 4 3 U Unlocked light 1 6 2 5 2 8 Index 2
39. n t find on these modules Unlike other modules designed to be used with the Agilent 83480A digital communica tions analyzer the Agilent 83491 2 3A modules do not include Channel keys or menus Also there are no GPIB programming commands for these modules 2 3 Operation Front Panel Features Front Panel Features Red light shows Selection to red data rate selected Triggering SELECT directly trigger Auxiliary Green light shows unlocked key on data outputs green data rate selected light 83493A 2500 Mb s SINGLE MODE CLOCK RECOVERY MO E SELECT 155 Mb s 2488 Mb s 155 Mbis 7 2488 Mbis 1062 Mb Oo 1250 Mbis Oo i 1082 oO o o o is Trigger 622 Mbis Oo Trigger 622 Mpls OC 1250 Mbis OC OnData 2125 Mbis 2500 Mbis OnData 2125 Mbis 2500 Mbis On Data 2500 Mbis Data Unlocked Clock da Clock Clock ke Auxiliary Outputs ee Auxiliary Outputs 3 Lo Auxiliary Outputs Electrical Optical Optical Input Output 780850 nm Output 1310 1550 nm 62 5 1 25m 10 Mw Max Data input and output Figure 2 2 Agilent 83491 2 3A front panels SELECT key Pressing this key changes the modulation rate of the input signal The recov ered and retimed clock trigger is sent to the mainframe The Trigger On Data selection is a bypass mode where the data stream directly triggers the main frame Refer to Block Diagrams on page 2 7 to view a schematic of the nor mal and bypass paths 2 4 UNLOCKED
40. nect the probe power cable to the Probe Power connector on the reference receiver module Attach the probe tip to the CAL hook that is located near the floppy disk drive Press the reference receiver module s front panel channel SETUP key Press Calibrate and then Calibrate probe 2 11 Operation Using Probes with an Agilent 83491A To compensate for other devices The information in this section applies to both optical and electrical measure ments Since the mainframe s CAL signal is a voltage source it cannot be used to calibrate to the probe tip when the units are set to Ampere Watt or Unknown Instead set the external gain and external offset to compensate for the actual characteristics of the device If you do not know the actual charac teristics you can refer to the typical specifications that came with the device 1 Press the reference receiver module s front panel channel SETUP key 2 Press External scale 3 Press Atten units Ratio Attenuation 1 1 and then Units Ampere Volt Watt or Unknown 4 Press Ext gain and enter the actual gain characteristics of the device 5 Press Ext offset and enter the offset introduced by the device 2 12 Agilent 83491A Specifications 3 3 Agilent 83492A Specifications 3 4 Agilent 83493A Specifications 3 6 Agilent 83491 2 3A Operating Specifications 3 7 Declaration of Conformity 3 8 Specifications and Regulatory Information Specifications Chara
41. ning the Instrument for Service The instructions in this section show you how to properly return the instru ment for repair or calibration Always call the Agilent Technologies Instrument Support Center first to initiate service before returning your instrument to service office This ensures that the repair or calibration can be properly tracked and that your instrument will be returned to you as quickly as possi ble Call this number regardless of where you are located Refer to Agilent Technologies Service Offices on page 4 23 for a list of service offices Agilent Technologies Instrument Support Center 800 403 0801 If the instrument is still under warranty or is covered by an Agilent Technolo gies maintenance contract it will be repaired under the terms of the warranty or contract the warranty is at the front of this manual If the instrument is no longer under warranty or is not covered by an Agilent Technologies mainte nance plan Agilent Technologies will notify you of the cost of the repair after examining the unit When an instrument is returned to a Agilent Technologies service office for servicing it must be adequately packaged and have a complete description of the failure symptoms attached When describing the failure please be as spe cific as possible about the nature of the problem Include copies of additional failure information such as the instrument failure settings data related to instrument
42. nt will do so Typically probes have standard attenuation factors such as divide by 10 divide by 20 or divide by 100 Because the following procedures include compensation for insertion loss of the clock recovery module do not perform the procedure To Compensate for Module Insertion Loss on page 2 9 The following probes are available for use with Agilent 83491A clock recovery modules Agilent N1020A TDR probe This passive probe 1 1 50Q provides a fixture for positioning and holding the probe tip on the device being tested Agilent 54701A 2 5 GHz active probe This is a 100kQ 10 1 probe Agilent 54006A 6 GHz handheld low impedance probe This passive probe 10 1 500 20 1 1kQ has an input capacitance of 0 25 pf Agilent 1163A 1 GHz resistive divider probe This passive 500Q probe has an input capacitance of 1 5 pf 2 10 Operation Using Probes with an Agilent 83491A To compensate for a passive probe Connect the probe to the Input connector on the Agilent 83491A clock recovery module 2 Attach the probe tip to the CAL hook that is located near the floppy disk drive 3 Press the reference receiver module s front panel channel SETUP key 4 Press Calibrate and then Calibrate probe To compensate an Agilent 54701A active probe Connect the Agilent 83491A output to the electrical measurement channel input Connect the probe to the Input connector on the Agilent 83491A clock recovery module Con
43. partment 4 4 Reference Error Messages Error Messages The following error messages are for the plug in module Typically the error messages indicate there is a problem with either the plug in or the mainframe This section explains what the messages mean and offers a few suggestions that might help resolve the error condition If the suggestions do not eliminate the error message then additional troubleshooting is required that is beyond the scope of this book Additional error messages are listed in the Agilent 83480A Agilent 54750A User s Guide for the mainframe Memory error occurred in plug in_ Try reinstalling plug in The mainframe could not correctly read the contents of the memory in the plug in O Remove and reinstall the plug in module Each time a plug in is installed the mainframe re reads the memory in the plug in module O Verify the plug in module is firmly seated in the mainframe slot O Verify the knurled screws at the bottom of the plug in module are finger tight O Install the plug in in a different slot in the mainframe 4 5 Od 0 0 OI Reference Busy timeout occurred with plug in Try reinstalling plug in Busy timeout occurred with plug in Try reinstalling plug in The mainframe is having trouble communicating with the plug in module Make sure there is a good connection between the mainframe and the plug in module Remove and reinstall the plug in module Verify t
44. ressing Run Find any signals on the channel inputs by pressing Autoscale See if any signals are present at the channel inputs by pressing Trigger Sweep Freerun After viewing the signal press triggered 5 Make sure Channel Display is on by pressing Channel Display on off on Make sure the channel offset is adjusted so the waveform is not clipped off the display Make sure the mainframe identifies the plug in module by pressing Utility then System config The calibration status of the plug in modules is listed near the bottom of the display in the box labeled Plug ins If the model number of the plug in module is listed next to the appropriate slot number then the mainframe has identified the plug in If known is displayed instead of the model number of the plug in module remove and reinsert the plug in module in the same slot If known is still displayed the mainframe may need to have the latest operating system firmware installed Options 001 and 002 provide this firmware on a 3 5 inch diskette To load new firmware follow the instructions provided with this diskette If you do not have the optional diskette contact your local Agilent Technologies service office refer to Agilent Technologies Service Offices on page 4 23 If the mainframe firmware is current and the plug in module is correctly installed then the memory contents of the plug in module are corrupt Contact a qualified service de
45. t Number Laser shutter cap 08145 64521 FC PC dust cap 08154 44102 Biconic dust cap 08154 44105 DIN dust cap 5040 9364 HMS10 dust cap 5040 9361 ST dust cap 5040 9366 To clean a non lensed connector Do not use any type of foam swab to clean optical fiber ends Foam swabs can leave filmy deposits on fiber ends that can degrade performance Apply pure isopropyl alcohol to a clean lint free cotton swab or lens paper Cotton swabs can be used as long as no cotton fibers remain on the fiber end after cleaning Clean the ferrules and other parts of the connector while avoiding the end of the fiber 3 Apply isopropyl alcohol to a new clean lint free cotton swab or lens paper Clean the fiber end with the swab or lens paper Do not scrub during this initial cleaning because grit can be caught in the swab and become a gouging element Immediately dry the fiber end with a clean dry lint free cotton swab or lens paper Blow across the connector end face from a distance of 6 to 8 inches using filtered dry compressed air Aim the compressed air at a shallow angle to the fiber end face Nitrogen gas or compressed dust remover can also be used 4 18 CAUTION Reference Cleaning Connections for Accurate Measurements Do not shake tip or invert compressed air canisters because this releases particles in the can into the air Refer to instructions provided on the compressed air canister As soon as the connector is dr
46. urements Keep connectors covered when not in use Use fusion splices on the more permanent critical nodes Choose the best con nector possible Replace connecting cables regularly Frequently measure the return loss of the connector to check for degradation and clean every connec tor every time All connectors should be treated like the high quality lens of a good camera The weak link in instrument and system reliability is often the inappropriate use and care of the connector Because current connectors are so easy to use there tends to be reduced vigilance in connector care and cleaning It takes only one missed cleaning for a piece of grit to permanently damage the glass and ruin the connector Measuring insertion loss and return loss Consistent measurements with your lightwave equipment are a good indica tion that you have good connections Since return loss and insertion loss are key factors in determining optical connector performance they can be used to determine connector degradation A smooth polished fiber end should pro duce a good return loss measurement The quality of the polish establishes the difference between the PC physical contact and the Super PC con nectors Most connectors today are physical contact which make glass to glass connections therefore it is critical that the area around the glass core be clean and free of scratches Although the major area of a connector excluding the glass may show s
47. ut circuits can also be damaged by electrostatic discharge ESD Before connecting any coaxial cable to the connectors momentarily short the center and outer conductors of the cable together Avoid touching the front panel input connectors without first touching the frame of the instrument Be sure that the instrument is properly earth grounded to prevent buildup of static charge Agilent 83492 3A Modules Maximum safe signal input level is 3 dBm On the Agilent 83480A press the Trigger key and then the Source softkey Then select trigger 2 the Agilent 83491 2 3A module for the trigger source On the Agilent 83491 2 3A module repeatedly press the SELECT key until a front panel light indicates the data rate of the signal See Figure 1 4 on page 1 6 Green and red data rate lights The data rate indicator lights change color between red and green to show which data rate is selected A red light does not indicate a problem A red light shows that the adja cent red data rate label is selected A green light shows that the adjacent green data rate label is selected Repeatedly pressing the SELECT key cycles through the selections in one color before switching to the opposite color On Agilent 83491A modules for example the first selection cycle shows 155 Mb s selected The second section cycle shows 1062 Mb s selected 1 5 Installation Installation Triggering Red light shows Green light shows Select unlocked red data
48. woe O s O ou O Tiger EENE oO onta 2125M O 200 mos Data Uniogied Clock a aust ary outputs Optical Bogsonm 1000 nm to 1600 nm inoutcon cdr Input and output connections versus wavelength 1 7 Agilent 83491 2 3A Modules At a Glance 2 2 Front Panel Features 2 4 Block Diagrams 2 7 To Display a Signal 2 8 To Compensate for Module Insertion Loss 2 9 Using Probes with an Agilent 83491A 2 10 To compensate for a passive probe 2 11 To compensate an Agilent 54701A active probe 2 11 To compensate for other devices 2 12 Operation Operation Agilent 83491 2 3A Modules At a Glance Agilent 83491 2 3A Modules At a Glance The Agilent 83491 2 3A are designed to operate in an Agilent 83480A digital communications analyzer These modules recover clock and data information at standard telecom and datacom rates The resulting trigger signal is made available to the Agilent 83480A mainframe via a connector located on the module s rear panel An external front panel cable passes the data signal with some insertion loss to the receiver module Table 2 1 Module Features Agilent Module Input Connector Selectable Rates Mb s 83491A 83492A 83493A 3G Agilent Boom wear owa woz 37 733 C3 50Q electrical Multimode fiber 62 5 125 um Single mode fiber 9 125 um 155 622 1060 1250 2120 2488 2500 155 622 1060 1250 2120 2488 2500 155 622 1250 2488 2500
49. y connect or cover it for later use If the performance after the initial cleaning seems poor try cleaning the con nector again Often a second cleaning will restore proper performance The second cleaning should be more arduous with a scrubbing action To clean an adapter The fiber optic input and output connectors on many Agilent Technologies instruments employ a universal adapter such as those shown in the following picture These adapters allow you to connect the instrument to different types of fiber optic cables Figure 4 8 Universal adapters Apply isopropyl alcohol to a clean foam swab Cotton swabs can be used as long as no cotton fibers remain after cleaning The foam swabs listed in this section s introduction are small enough to fit into adapters Although foam swabs can leave filmy deposits these deposits are very thin and the risk of other contamination buildup on the inside of adapters greatly out weighs the risk of contamination by foam swabs Clean the adapter with the foam swab 3 Dry the inside of the adapter with a clean dry foam swab 4 Blow through the adapter using filtered dry compressed air Nitrogen gas or compressed dust remover can also be used Do not shake tip or invert compressed air canisters because this releases particles in the can into the air Refer to instructions provided on the compressed air canister 4 19 Reference Returning the Instrument for Service Retur
50. y tolerance for reflection and loss important Do your specifica 4 10 Reference Cleaning Connections for Accurate Measurements tions take repeatability uncertainty into account e Will a connector degrade the return loss too much or will a fusion splice be re quired For example many DFB lasers cannot operate with reflections from connectors Often as much as 90 dB isolation is needed Connecting Body and Ferrule 2 5 mm Mechanical Retainer Fiber 125 um actual fiber s diameter is smaller than a human hair Alignment Key Figure 4 2 Basic components of a connector Over the last few years the FC PC style connector has emerged as the most popular connector for fiber optic applications While not the highest perform ing connector it represents a good compromise between performance reli ability and cost If properly maintained and cleaned this connector can withstand many repeated connections However many instrument specifications require tighter tolerances than most connectors including the FC PC style can deliver These instruments cannot tolerate connectors with the large non concentricities of the fiber common with ceramic style ferrules When tighter alignment is required Agilent Technologies instruments typically use a connector such as the Diamond HMS 10 which has concentric tolerances within a few tenths of a micron Agi lent Technologies then uses a special universal adapter which allows other cable
51. yed is also included in this chapter Before calling Agilent Technologies or returning the unit for ser vice a few minutes spent performing some simple checks may save waiting for your instrument to be repaired If the mainframe does not operate Is the line fuse good Does the line socket have power Is the unit plugged in to the proper ac power source Is the mainframe turned on Is the rear panel line switch set to on Will the mainframe power up without the plug in module installed If the mainframe still does not power up refer to the optional Agilent 83480A Agilent 54750A Service Guide or return the mainframe to a qualified service department If the plug in does not operate Is the plug in module firmly seated in the mainframe slot Are the knurled screws at the bottom of the plug in module finger tight Is the clock recovery module set to the modulation rate of the input signal If other equipment cables and connectors are being used with the plug in module are they connected properly and operating correctly Review the procedure for the test being performed when the problem ap 4 3 AN Reference In Case of Difficulty peared Are all the settings correct Can the problem be reproduced Are the connectors clean See Cleaning Connections for Accurate Measure ments on page 4 10 for more information Perform the following procedures Make sure that the instrument is ready to acquire data by p
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