Agilent Technologies 2 manuale d’uso

A g il en t 8 3 4 9 1 / 2 / 3 A C l o c k R eco v e r y M o d u l e s U s e r ’ s G u i de[...]

ii © Cop yright 20 00 Agilent T echnolo gies All Rights Reserved. Repro- duction, adaptation, or trans- lation without prior writ ten permi ssion is prohibit ed, except as allowed under copy- right laws. Agilent P art No. 8349 1-90013 Printed in USA Februar y 2000 Agilent T echnolo gies Lightwave Division 1400 Fountaingrove Parkway Sant a Rosa, CA[...]

iii General Sa fety Considera tions General Safety Considerat ions This product has been desig n e d and test ed i n accord ance wi th IE C P ublica- tion 61010-1 , Safe ty Req uirements for Electri cal Equi pment for Measurem e n t, Control an d Laboratory Use, and has been suppli ed in a safe condition. T he instruction d ocumentation contains i [...]

iv Gener al Safet y Consider ations Technolo g i e s part n umber 2110-0449. • For 220/240V ope ration, use an IEC 127 5 × 20 mm, 0.16 A, 250 V, Agilent Technolo g i e s part n umber 2110-0448. CAUTIO N Before sw itching o n this instrum ent, make su re that the li ne voltage selecto r switch is set to the line voltage of the power supply and th[...]

Contents Contents-1 General Saf ety Consider ations iii 1 Installat ion Inst alla tion 1-2 2O p e r a t i o n Agilent 83491/2 /3A Modules—At a Glance 2-2 Front-Panel Features 2-4 Block Diagrams 2-7 T o Dis play a Sig nal 2-8 T o Comp ensate fo r Module Insert ion Loss 2-9 Using Prob e s w ith an Agilent 8 3491A 2-10 3 Speci fication s and Regula [...]

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1 To insta ll the module 1-3 To connect cable s to an Agilent 83492A 1-7 Installa tion[...]

1-2 Instal lation Instal lation Installat ion Agilent 834 91/2/3A modu l e s require th at firmware re vision A.06.25 o r later be install e d in the Agilent 83480A. If you wis h to ins tall the module in an Agile nt 54750A digitizi ng oscill oscope, you must first inst all the Agilent 83480K communi cations firmware upgrad e kit. T o check the Agi[...]

1-3 Insta llation Installatio n To install the module 1 Verify t hat all system components ordere d have arrived by co mparing the shipping f orms to the original purchase order. In s pec t all shipping cont ai n e r s. The sh ipment include s: ❒ An Agil e n t 83491/2/3A Clock Recovery Module ❒ Fiber-optic adapter cable (Agilent 83492 /3A modul[...]

1-4 Instal lation Instal lation Figure 1-2. Position of m o dul es in the mainframe 3 Clean all o ptical interfaces as described in “Cleaning Connections for Accura te Measurem e nt s” on page 4- 10 , bef ore making measurem ents . 4 Perform the foll owing steps if you’re inst alling an Agilent 83492/3 A module: a Unscrew and re move th e fib[...]

1-5 Insta llation Installatio n Figure 1-3. The adapt er cable CAUTIO N Agil ent 83491A Modules: Maximum safe s ignal i nput level is ±5V . The inp ut circuits can also be damaged by el e ct r os tatic discharge (ESD). Be fore connecting any coaxial cable to th e connectors, mome ntarily short the ce nter and outer condu ctors of the cable tog e t[...]

1-6 Instal lation Instal lation Figure 1-4. Front-panel lights 9 Confir m that the Unlo cked light is of f. 10 Obser ve the Clo ck and Data outp uts on an oscilloscope. Waveforms should be presen t. The instrum ent is now ready for you to b egin making meas urements.[...]

1-7 Insta llation Installatio n To connect cables t o a n Agilent 83492A On Ag ilent 83492A modules, the front-panel fiber -opti c connectors reverse input an d output roles dependi ng on the wavelength of the signa l. Signals in the 750 nm to 860 nm wavelength ra nge are input to the left connector an d output fr om the right conne ctor . Sig nals[...]

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2 Agilent 83491/2 /3A Modules—At a Glance 2-2 Front-Panel Features 2-4 Bloc k Diagra ms 2-7 To Display a Signal 2-8 To Compens ate for Module Ins ertion Loss 2-9 Using Prob e s w ith an Agilent 8 3491A 2-10 To comp ensate for a pa ssive prob e 2-11 To compen sate an Agilent 54701A active p robe 2-11 To compen sate for other dev ices 2-12 Operatio[...]

2-2 Operatio n Agilen t 83491/2/3A Modules—At a Glance Agilent 83491/2/3A Modules—At a Glance The Agile nt 83491/2/3A are desi g n ed to operate in an Agilent 83 480A digital communications anal y ze r . These modules recove r clock and data information at stand ard teleco m a nd datacom rat es. The resu lting trigge r signal is mad e available[...]

2-3 Operatio n Agilen t 83491 / 2 /3A Modules—At a Gla nce WAR NIN G Light ener gy can radiate from the fron t panel OUTPUT connector s on Agilent 83492A and 83493A modules. The light emitted from these conn ectors is th e slightl y attenuate d light th at is inpu t to the fro nt- panel INPU T connector . Use with Ag ilent 71603B or 71612B Error [...]

2-4 Operatio n Front -Panel Feat ures Front-Panel Feat ures Figure 2-2. Agilent 83491/2/3A front panels SELECT key Press ing this key cha nges the modulatio n rate o f the in put sign al. The recov- ered an d retimed cl ock trigger is sent to the main frame. Th e T rigger On Data select ion is a bypass mode wher e the da ta strea m directl y trigge[...]

2-5 Operatio n Front-P anel Featur es UNLOCKED indica tor This light shows when clock r ecovery cannot be established on the s i gnal . If a clock rate is selec ted, the trig ger output to the mainfram e is disabled to pre - vent free-r un triggering. Howe ver in bypass mod e ( T rigger On Data sele cted), trigge ring is not di sabled. When t he UN[...]

2-6 Operatio n Front -Panel Feat ures Reco vered Clo ck The recovered clock signal is route d d irectly to the Agilent 834 80A mainframe through th e module’ s rear pane l. This output has a lowe r jitter modulat ion bandwidt h t han the front-panel CLOCK Auxili ary Output . Becau se of th e reduced jitter modulati on bandwi dth on the mainframe [...]

2-7 Operatio n Bloc k Diagrams Block Diagrams Figure 2-3. Agilent 83491A Block Diagram Figure 2-4. Agilent 83492A and 83493A Block Diagram[...]

2-8 Operatio n To Displa y a Signal To Display a Signal 1 Install the module as described in “ To install the modu le” on page 1-3. Be sur e to conn ect all of the c ables as de scribed in t he proced ure. 2 Repea tedly press t he SELECT key on the cloc k recovery m odule until th e front- panel lig ht indicates the proper data rate of the sign[...]

2-9 Operatio n T o Compensa te for Module I nsertion Lo ss To Compensate for Module Insertion Loss The fol lowing step s allow yo u to enter an offs et to compe nsate for the in ser- tion loss of the clock recover y modu l e. Th i s provide s accurate amplitude mea- surements at the in put to the clock recovery module. 1 Disconnect th e cable from [...]

2-10 Operatio n Using Pr obes with an Agile nt 83491A Using Probes with an Agilent 83491A Y ou can use exter nal p assive and active probes with t he Agi lent 83491A elec- trical clock recover y module. The procedures in this secti on generate vertical scale fac tors. These factor s are applied to the calib ration of the re ference rece iver modu l[...]

2-11 Operatio n Using Pro bes with an Agilent 83491 A To compensate for a passive probe 1 Connec t the probe to the Input connecto r on the Agilent 83491A clock reco ve r y modu le. 2 Atta ch the prob e tip to the CAL hook that is located ne ar the floppy di sk drive. 3 Press th e reference r eceiver module ’ s front-pane l channel SET UP key. 4 [...]

2-12 Operatio n Using Pr obes with an Agile nt 83491A To compensate for other devi ces The informatio n in th i s sectio n appl ies to both optical and electrical measure- ments. Since the mainframe’ s CAL signal is a vol tage source, it cannot be used to calibrat e to the probe tip whe n the u nits are set to Amper e, W att, or Unknow n. Instead[...]

3 Agilent 834 91A Specification s 3-3 Agilent 834 92A Specification s 3-4 Agilent 834 93A Specification s 3-6 Agilent 834 91/2/3A Operating Specif i cat ions 3-7 Declaration of Conformity 3-8 Specifications and Re gulatory Inform ation[...]

3-2 Specific ations and R egulatory I nformation Specifica tions and R egulatory Info rmation Specifications and Regulatory Information This ch apter lists sp ecifications a nd characteristics of the Agilent 8 3491/2/3A. Speci fication s apply over th e temperat ure range +15 ° C to +35 ° C (unless oth- erwise noted) afte r the instrument’ s te[...]

3-3 Specifi cations and Regulator y Information Agilen t 83491A Spec ifications Agilent 83491A Specif ications Table 3-1. Agilent 83491A Specifications Clock recove r y rates (NRZ cod i ng ) 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 ±0.1% ±0.1% ±0.1% ±0.1% ±0.1% ±0.1% ±0.1% Data trigger ing (char[...]

3-4 Specific ations and R egulatory I nformation Agilen t 83492A Spec ifications Agilent 83492A Specif ications Table 3-2. Agilent 83492A Specifications (1 of 2) Wavelength range (c haracteristic ) 750 nm to 860 nm and 1000 nm to 1600 nm Optical IN PUT and OUTPUT fiber (c haracteristic ) 62.5/125 mult imode Optical ins ertion loss (thr ough path) a[...]

3-5 Specifi cations and Regulator y Information Agilen t 83492A Spec ifications DA T A and C LOCK electr ical return lo ss 50 MHz throug h 2000 MHz (characteri stic) 2000 MHz thro ugh 2500 MHz (characteristi c) ≥ 10 dB ≥ 6 dB a. Minimu m loss in 850 nm window . b. Single-m ode backr eflecti on tested with F C/PC adapt er and si ngle-mod e fiber[...]

3-6 Specific ations and R egulatory I nformation Agilen t 83493A Spec ifications Agilent 83493A Specif ications Table 3-3. Agilent 83493A Specifications Wavelength range (c haracteristic ) 1000 nm to 1600 nm Optical IN PUT fiber (characte ristic) 9/125 single mode Optical ins ertion loss (through pa th) ≤ 1.5 dB Opti cal re turn los s a a. Tested[...]

3-7 Specifi cations and Regulator y Information Agilent 8349 1/2/3A Operatin g S p ecification s Agilent 8 3491/2/3A Operating Specifications Table 3-4. Agilent 83491/ 2/3A Operating Specifications Use Indoo r Temperature Operatin g Non-opera t ing 0 ° C to +55 ° C –40 ° C t o +70 ° C Alti tude Operatin g Non-opera t ing 4600 m (15,000 ft ) 1[...]

3-8 Specific ations and R egulatory I nformation Declara tion of Conform ity Declaration of Conformity[...]

4 Front-P anel Optical Ad apters 4-2 In Case of Difficul ty 4-3 Erro r Messages 4-5 Electro static Discharge Inform ation 4-8 Cleaning Connections f or Accurate Measurements 4-10 Return ing the Instru ment for Servic e 4-20 Agilen t Techno logies Ser vice Off ices 4-23 Reference[...]

4-2 Refe rence Front -Panel Opt ical Adapt ers Front-Pan el Optical Ada pters Front Pan el Fiber-Optic Adapt er Desc ript ion Agilent Part Numb er Diamond HMS -10 81000AI FC/PC a a. The FC/PC adapter is the sta ndard ad apter supp lied wi th the ins trument. 81000FI D4 81000GI SC 81000KI DIN 81000SI ST 81000VI Biconic 81 000WI Dust C overs FC conne[...]

4-3 Reference In Case of Difficu lty In Case of Difficulty This section p rovides a list of suggest ions for y ou to fo llow if th e plug-in mod- ule fa ils to ope rate. A li st of mess ages th at may be displayed is also inc luded in this chap ter . Before ca lling Agi lent T echn ologies or re turning the un it for ser- vice, a few mi nutes spent[...]

4-4 Refe rence In Case of Difficu lty peare d. Are a ll the s ettings c orrect ? Can th e proble m be rep roduced? ❒ Are th e connectors cl ean? See “Cl eaning Conn ections fo r Accurate M easure- ments” o n page 4-10 for more informati on. ❒ Perfor m the foll owing proce dures: 1 Make s ure t hat the instrument is re ady to a cquire data b[...]

4-5 Reference Error Messages Error Me ssages The following error me ssages a re for the plug-i n module. T ypicall y , the err or messa ges indica te there is a p roblem wi th either th e plug-in o r the mainfra me. This section expl ai n s what th e message s me an and offe rs a few sugg estions that mi ght help r esolve the e rror cond ition. If [...]

4-6 Refe rence Busy ti meout occurr ed with plu g-in_:Tr y reinstal ling plug-i n Busy timeout occurred with pl ug-in_:Try re installing plug-in The mainframe is having tro ubl e commu n i cating with the plug-in module. Make sur e there is a goo d connecti on between the mainframe an d t he plug-in modu le. ❒ Remove and re install the plu g-in m[...]

4-7 Reference Plug- in is not supp orted:Sy stem firm ware upgrade is needed der the Agile nt 83480K communications firmwa re k i t and ins tall according to the instr uctions. ❒ The Agilent 83480A , A gi lent 54750A mainframes do not accept plug-in mod- ules des i gne d for use with the Agilent 5 4710A, 54720A. Plug-in is no t supported:System f[...]

4-8 Refe rence Electro static Discharge In formation Electrostatic Discharge Information Electr ostatic d ischarge (ES D) can damage or des troy elect ronic compon ents. All work on electronic assemblies shou l d be performe d at a static-saf e wor k station. T he following f i gure shows an exampl e of a static - safe work station using two type s[...]

4-9 Reference Electro static Discharg e Information Both ty pes, when us ed toget her , pr ovide a si gnificant level of ESD protectio n. Of the tw o, only the ta ble-mat an d wrist-str ap combinat ion provide s adequat e ESD prote ction when used alone. T o ensu re user safety , the static-safe access ories must provi de at least 1 M Ω of isolat[...]

4-10 Refe rence Clea ning Con nections for Accu rate Meas urements Cleaning Connections for Accurate Measurements T oday , advances in measuremen t capabi lit i es make conne ctors and connec- tion techniques more imp ortant th an ever . Damage to the connecto rs on cal i- bration and verifi cation devices, test ports, cables, and ot he r device s [...]

4-11 Reference Clea ning Con nections for Accu rate Me asurements tions take repeata bility uncertainty into accou nt? • Will a connect or degrade the return lo s s too much , or will a fusion splice be re- quired ? For e xample, m any DFB lasers ca nnot oper ate with reflecti ons from connectors . Ofte n as much as 90 dB isolati on is needed. Fi[...]

4-12 Refe rence Clea ning Con nections for Accu rate Meas urements Figure 4-3. Universal ada pters to Diamond HMS-10. The HMS-10 encases th e fiber wi thin a soft nickel silver (Cu/Ni/Zn) center which is surrounde d b y a toug h tungsten carbide casing, as shown in Figure 4-4. Figure 4-4. Cross- section of the Diamond HM S-10 connector . The nickel[...]

4-13 Reference Clea ning Con nections for Accu rate Me asurements The so ft core, wh ile allowing p recise cen tering, i s also the ch ief liabilit y of the conne ctor . The soft material is easi ly damaged. Care mus t be taken to mini- mize excessive s cratching and wear . Whi l e mi nor wear is not a problem if the glass face is not affected, scr[...]

4-14 Refe rence Clea ning Con nections for Accu rate Meas urements Use the follow ing gui delines to achie ve the b est poss ible per formanc e when making measur ements on a fiber -op tic system: • Never use meta l or sharp object s to cl e an a connect or and never scrape the connector. • Avoi d matching g el and oils. Figure 4-5. Clean, pro [...]

4-15 Reference Clea ning Con nections for Accu rate Me asurements Figure 4-7. Damage from i mproper cleaning . While t hese often w ork well on first inse rtion, they are great di rt magnet s. The oil o r gel gr abs and h olds grit that is then gro und into the en d of the fiber . Also , some early ge ls were desi gned for us e with the FC, no n-co[...]

4-16 Refe rence Clea ning Con nections for Accu rate Meas urements • Keep con nectors covered when not in use. • Use fusion spli ces on the m ore perma nent criti cal nodes. Choose th e best con- nector possible . Replace connecti ng cables r egularly . Frequent ly measur e the return los s of the c onnector to check for de gradation, and clean[...]

4-17 Reference Clea ning Con nections for Accu rate Me asurements V isual inspection of f iber en ds Visual inspection of fiber ends can be helpful. Contami nation or imperfecti ons on the cable end face can be detected as well as cracks or chips in the fiber itself. Use a micros cope (100X to 200X magnifi cation) to inspect the entire end face fo [...]

4-18 Refe rence Clea ning Con nections for Accu rate Meas urements T o clean a non-lense d conne ctor CAUTIO N Do not use any type of foam swab to clean optical fiber e nds. Foam swabs can leave film y deposits on fiber ends that can de grade performa nce. 1 Apply pur e isopropyl alcoh ol to a clean lint-fre e cotton swab or lens pape r. Cotto n sw[...]

4-19 Reference Clea ning Con nections for Accu rate Me asurements CAUTIO N Do not shake , tip, or inver t compre ssed air c anister s, becaus e this rel eases partic les in t he can i nto the air . Refer to instructio ns provi ded on the compressed air canister . 7 As soo n as the connect or is dry, con nect or cove r it for later u se. If t he per[...]

4-20 Refe rence Returni ng the Instrument for Servi ce Returning the Instrument for Service The instruct ions in t his sec tion show you how to prop erly re turn the i nstru- ment for repair or calibration . Always call the Agi lent T echno logies Ins trument Suppor t Center first to initiate s ervice before r eturnin g your i nstrument to a serv i[...]

4-21 Reference Returning the In strument for Service infor mation sh ould be returned with th e instrum ent. • Type of service requir ed. • Date instrument was return ed for re pair. • Descripti on of the problem: • Whet her probl em is c onstant or intermi ttent. • Whet her ins trument is tempe rature-se nsitive . • Whe ther inst rumen[...]

4-22 Refe rence Returni ng the Instrument for Servi ce Sealed Air Corpor ation (Commerce, California 900 01). Air Cap look s l ike a plast ic sheet fill ed with air bubb les. Use the pink (antist atic) Air Cap ™ to reduc e static electr icity. Wr apping the ins trument sev eral times in this ma- teria l will pro tect the instrume nt and p revent [...]

4-23 Reference Agilen t T echnologie s Service O ffices Agilent Technologies Service Offices Befor e returni ng an ins trument f or service , call the Agile nt T echno logies Instrumen t Support Center at (80 0) 403-0801, visit th e T es t and Measurement W eb Sites by Country page at http : / /www .tm.agi l ent. com/tmo/country/English / index .ht[...]

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Index Index- 1 A adapter cable, 1-3 , 1- 4 Agil ent 54701A a ctive p robe, 2-11 Agil ent 83492A connections, 1-7 maximum input level, 1-5 Agilent o ffices, 4-23 B Bellcore G R-253-CORE, 2-5 block diagram, 2-7 bypass mode, 2- 4 , 2-5 C cabinet , cleaning, ii i calibration cycle, 3-2 care of cab inet, iii care of fiber optics, 1-2 channel key, 1- 2 s[...]

Index -2 Index I IEC P ublicat ion 610 10-1, iii input connector, 4-10 Input connector, 1- 2 , 1-7 input connector, 2-2 input signal, maximum safe, 1-5 insertio n loss, 2-3 , 2-6 compensation, 2- 9 instrume nt returning for service, 4-20 ITU- T G.957, 2- 5 M mainframe troub leshooting, 4- 3 maximum inpu t level, 1-5 O Output connector, 2-5 P packag[...]