Wandel & Goltermann OLP-10 User manual

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OLP-10
Optical Power Meter
BN 2229103, All Series
Service
Manual
Wandel&Goltermann
CommunicationsTest Solutions
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Contents
1 lntroduction
....................................
1.1 General Notes 1-1
1.2 MeasurementEquipment
........................... 1-1
Important Notes
2.1 Safety Notes
..................................... 2.1
2.2 Anti-static Measures ...............................2-1
2.3 Repair Guidelinesfor Boardswith SMDs ...............2-2
2.3.1 Introduction
...................................... 2-2
2.3.2 TestTechniquesforSMDBoards ..................... 2-3
2.3.3 SMD Handling Instructions ..........................2-3
2.3.4 SMT Soldering and Repair Procedures
................. 2-4
2.4 Cleaning Instructions
............................... 2-6
2.4.1 Cleaningthe Frontpaneland Enclosure ................2-6
2.4.2 Cleaning Connector
................................ 2-6
3 Mechanical DesignIAssembly lnstructions
3.1 InstrumentCodes
................................. 3.1
3.2 Assembly Instructions .............................. 3.1
3.3 Software Upgrade ................................. 3.1
4 Selftests
4.1 Overview
........................................ 4.1
4.1.1 Power-OnTest
................................... 4.1
4.1.2 Selftest Mode ..................................... 4.1
5 Omitted
6 Fault Localization. Component Level
6.1 Voltage Supply
................................... 6.1
6.2 OnlOff Control .................................... 6.1
.............
6.3 +5 V Power Supply and -5 V Power Supply 6.1
6.4 ReferenceVoltage Generation (U70)
.................. 6-1
.............................
6.5 Battery Monitor (U6.2). 6-1
....................
6.6 Clock Oscillator 1ProcessorClock 6-2
6.7 Processor Function ................................ 6.2
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Service Manual OLP-101-15
I Introduction
1.1 General Notes
Beforestarting repairs, make sure that you are familiar with the safety measures described in
Chapter
2.1.
Chapter 2 containsfurther, irnportantinformationabout measurementtechniquesand repair
methods.
1.2 Measurement Equipment
. -- -
Equipment
1OMS-100 or OMS-200Mainframe
with
OCDlOLS(850 f 2 nm, -20dBm) BN2202192.01
OCDIOLS(131011550
f 2 nm, 0dBm) BN 2202192.06
OCDIOLP (specialcalibr.
at -20 dBm) BN2225192.02
OLP-110BN 2201102
OLA-100BN2206101
1 oscilloscope
Troubleshooting
+ alignment
Chapters
6 - 7
Functioncheck
Chapter
8
1 2 singlemodecable, W&Q type K3lxx 1.. I x
1frequencycounter
1digital multimeter
x
x
1 multimode cable, W&Q type K30xx
x x
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Service Manual
OLP-101-15
2 Important Notes
2.1 Safety Notes
Special safety notes for optical level meters
You shouldalso readthe notes inthe OperatingManual.
Caution!
The levelmeter can be operated with externallaseror LED sources.The laser or LED beam
is invisibleto the human eye but may neverthelesscause permanenteye injuries.
Beforeoperatingthe instrumentfamiliarizeyourself withthe following safety notes and
measures:
Safety notesand measures
Always keeptothe agreedsource safetyprocedures.
Donot turn onthe sourceuntil all the opticalfiber cables have been connected upproperly.
Only properlyqualifiedtechnicians with the appropriate authorizationmaycarry out repairs.
They must befamiliarwiththe relevant safety regulationsandthe associatedrisks.
Areas mustbedesignatedas suchandproperlysecuredas stipulatedbythe relevantsafety
regulations (see Section"WarningSigns").
When opticalequipmentsare beingoperated, safety regulationsto IEC 825, EN60825
(Europe) and 21CFR1040.10 (Japan)must always be observed.
2.2 Anti-static Measures
Electrostaticchargesandfields may damage or destroy semiconductorcomponents.
Itis,therefore,essentialto protect allsemiconductor components inthe instrumentfrom
electrostaticcharges andfields.
When the instrumentis initsenclosure,there are noproblems.Whenthe instrumentisopened,
the DIN40 021warningsymbol on
- boardsand
- assemblies
that are sensitive to STATIC reminds you that specialprotective measures haveto betaken
A warning symbol according to DIN 40021
Special measures
Groundedperson Only grounded personsusingananti-staticworkstationshallwork on
the instrument.
Groundedbracelet Agroundedbraceletisusedto earthtechniciansworkingatanti-static
workstations.
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Service Manual OLP-101-15
Test Techniques for SMD Boards
Never make direct connections (e.g. with a probe) to SMDs when you are checkingthem out.
Instead,use tracks, test padsor vias.
If you are usinga special probe with a sprung prod,only make contact at the foot of the
component (see Figure 2-1).
Fig. 2-1
Makjngmeasurementson SMD boards
SMD HandlingInstructions
As incorrect handlingof SMD components affects their characteristics, specialcare must be
taken. For example, even minor contaminationof the SMD pins,say afingerprint, prevents
effective wetting during soldering and so causes solderingdefects.The separation between
pins isoften so smallthattraces of solder leftby unsuitabletools can cause shortcircuits.
Always observe the following
rules
- Only use special SMD tools and equipment.
- Itisalways bestto use special SMD tweezers.
- HandleSMDs inthe originalcondition(as delivered).
- Only use the originalpackagingto store and transport SMDs (component identification).
- Nevertouch SMDs with your barefingers.
- Do not touch SMD pins (evenwith normaltools, for exampletweezers, etc.). Special SMD
test equipment, liketest tweezers, etc. may however be used.
- SMDsthat havebeen dropped must bethrown away (hairlinecracks, especiallywith larger
components).
- SMD identitycheck (measurementof R and C, etc.) shouldonly be carriedout usingspecial
SMD test tweezers if the components have not beeninsertedina board.
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Service Manual OLP-101-15
Soldering SMDs into position
- SMDs without pins
Use hotgas. The solder must be flowing on both pads simultaneously.
- SMDs with pins
Use a miniaturesoldering ironor hot gas. Diagonallyopposite ICpins must be soldered
alternately.
- Check the joint with a magnifyingglass (see Figure2-3) for bridging,dry joints, cracks and
holes, the solderingsurface (smooth and evenly shiny), solder drops, splashes and the
correctpositioningof the SMD.
\ bad
Fig. 2-3
Examplesshowing soldered SMDs
Repairing torn-off soldering pads
Ifa solderingpad foran SMD componentwith pins (IC, PLCC, SOTetc.) has beentornoff,
solderthe componentto the boardfollowingthe usualguidelines and repairthe defectivepad
inthe followingway:
A varnishedwire (d -- 0.2 mm) is connectedfrom the componentpinto a place of contact near
the pad. Itisbestto useavia. Ifthis is notpossible,thewire canbesolderedto a solderingpad
(as large as possible)of anSMDcomponent.
Inthe case of SMDswithout pins (mini melf
/ melf resistors,diodes tantalurn~multi-layer
capacitors, chip resistors,C trimmers, etc.), measuresmustbetakento ensurethe mechanical
stabilityof the solderedjoint if a soldering padis missing.
1 Solder one sideof the componentto a soldering pad. Connectthe otherside to a via or an
SMDsoldering padwhich shouldbe as large as possiblewith a wire (d
= 0.6 mm, if
necessaryinsulated).The wire should not be longerthan 10 mm.
2 Ifthe methodof repair describedin 1. cannot be used, the componentis held inplacewith
anadhesive.
- Dotthe adhesive onthe board.
- Placecomponenton board.
- Cure adhesive (100 'C, 20 min).
- Solderwire (varnished, 0.2 mm)to SMD pinand connectto suitable contact point.
Ifthere is nosuitablecontact point nearthe repair,or it is essentialto use connections of
minimumlength, any wide tracks can be usedor the solder resist andthe blackoxide can be
scratchedfrom any convenientarea and the wire solderedto
it.
Recommendedsolder:wire solder, SnPb 63 d = 0.6 rnmor d = 0.3 mmwith FSW-32flux.
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Service Manual
OLP-101-15
Mechanical DesignlAssernbly Instructions
instrument Codes
You will find the series number onthe front panel.
Assembly Instructions
Disassembly
1 Removeblack rubber ring <C>.
2
Removethe uppersection <A> of the shockproof casing.
3 Remove battery compartment cover.
4 Removethe OLP from the lower section
<B> of the shockproof casing.
5 Removethe 4 screws at the rear of the instrument (2 inthe batterycompartment).
6 Removethe upper section of the casing.
Fig. 3-1
Front view of the OLP
Software Upgrade
The software is stored inthe EPROM U14.
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Service Manual OLP-101-15
4 Selftests
4.1 Overview
4.1 .I Power-OnTest
After switch-on,the instrument carries out a power-ontest (EEPROMtest).
If a fault isdetected, error message E3 is displayed.
Select the selftestfor more checks.
4.1.2 Selftest Mode
The selftestcomprisesthe RAM test, EPROMtest and EEPROMtest.
Calling the test
. .
The instrument isoff.
Holddownthe [HOLD] key.
Turn onthe instrumentand holddownthe [ONIOFF] keyfor > 1 s.
Then releasebothkeys.
Status indicator onthe display
The course of the test is shown inthe lambdafield (wavelengthfield).
Any error message is also displayedinthe lambdafield.
Table 4-1
Display
2
Test status at port 5.7
Ifthe display is defective or the fautt symptoms are inconclusive,the test status can also be
measuredat port
5.7 onthe microprocessor (U10 pin 60).
Function
RAM-test
- The defautt value for port 5.7 is HIGH.
- Whenthe test is started, the port is LOW.
- Ifthe test is ok, port 5.7 goes HIGH.
- If the test finds a fault, the port stays LOW.
See Chapter
6 "Fault Localization, Component Level"for further fautt localization.
Duration
3 s
Error message
El
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Service Manual OLP-101-15
5 Omitted
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Service Manual OLP-101-15
6 Fault Localization, Component Level
6.1 Voltage Supply
Nominalbatteryvoltage (point H02 to H03):2.2 V to 3.5 V
6.2 OnIOff Control
Switchingthe instrument on
Turn onthe instrumentby pressingthe ONIOFF key.
Point H03: approx. -0.2
V (Q1 andthen U1.2 are turned on)
U11 pin12: Delayedhighafter low (RESET)
Signal CPFF-INIU11 pin 11
: High
Signal INT2/U11pin20: High
Permanentoperation
Pressthe ONIOFF key for >2 s at power-on.
Signal PERM_IN/U11pin 10: <I
V after approx. 2 s.
Switchingoff the instrument
Turn off the instrumentby pressingthe ONIOFFkey.
Signal CPFF-INIU 11 pin 11
:
Low pulses (Q2 on)
SignalINT2/U11pin20: Lowafter high
Referencepoint: Groundconnectionof C2 (analogground)
6.3 +5
V Power Supply and -5 V Power Supply
Measurethe supply voltages. Referencepoint:Groundconnection of C2 (analogground).
U2 pin
5: +5.00 V f 250 mV
U3 pin5: -4.90 V
+ 250 mV
6.4 Reference Voltage Generation (U7)
Checkthe referencevoltage for the A/D converter. Referencepoint: Ground connection of C2
(analogground).
U7 pin6: +2.50 V+ 10 mV
U7 also supplies avoltage VTEMP (at U7pin3) which is proportionalto temperature.
At 25 OC: VTEMP
= 690 mV; TC = +2.3 mV/K (allapproximate values).
6.5 Battery Monitor (U6.2)
The LOW-BAT signal (U6.2 pin 5) goes from highto low if the voltage VBAT goes below2.2 V.
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Service Manual OLP-101-15
-3 dBm input levelat 1310 nm
lnput circuit range
1 active.
Signalat US.1pin 1/U8 pin 14:
-15
dBm input levelat 1310 nm
lnput circuit range
2 active.
Signal
at US.1pin 1/U8 pin 14:
-40 dBm input levelat 1310 nm
lnput circuit range 3 active.
Signal at U5.1 pin5/U8 pin 14:
6.10 ADC
. ...
Carry out checkswith.adigital multimeter and frequency counter.
U8 pin5: 32.768 kHz (clock)
U8pin18: 1.28Vf15mV
U8 pin 13: -4.5 to -5.5 V
U8 pin24: 4.5 to5.5 V
6.11 FrequencyDetectionIFrequency Measurement
Usethe test setup described in Chapter 6.9, but: FMOD = 1000Hz
Signalat U6.1 pin7: 1000 Hz (FMOD)
FAN signalat U16.1 pin 1 :
500 Hz (FMOD12)
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Service Manual OW-101-15
7 Alignment lnstructions
General Notes
The followingdata are stored in EEPROM U13:
- Linearity correctionsfor 1310 nm
- Absolute levelcorrectionsfor 850 nm, 1310 nm and 1550 nm
- Temperaturealignment data
So that these alignmentscan be carriedoutwhenthe instrument isserviced, instrumentsfrom
series C have a special integralalignment routinewhich makes it possibleto recordandstore
the alignment values. This software can be retrofittedto series A and B instruments (EPROM
U14).
7.2 Required Equipment
1OMS-100 or OMS-200Mainframe
1 OCDIOLS (850
f 2 nm, -20 dBm) BN 2202192.01
1 OCDIOLS (131011550 2 nm, 0 dBm) BN2202192.06.
1OCD/OLP (specialcalibratedat -20 dBm) BN 2225B2.02
1 OLP-110 BN 2201102
1OLA-100BN 2206101
2 singlemode cable K3l xx
'.
1 muhimodecable K3Oxx
7.3 Accuracy
Wavelengthdependence
The technicaldataof the OLP-10115are stronglywavelength-dependent.Therefore, sources
withselectedwavelenthsare requiredto
carry out alignments. Ifthewavelengthsof the sources
differ from the nominalwavelengths,the measurementerror of the OLP-lo/-15 may increase.
7.4 Preparations
- Ambient Conditions: Moderate labconditions, 23 'C f 3 'C.
- Beforecarryingout the function test, the opticalconnectors must be carefullycleanedand
inspected.
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Service Manual OW-101-15
Test setup 3, for alignment at -20 dBm 1850nm
u
OCD BN 2202192.01
Instrument settings
OLS: Lambda
= 850 nm, level = -20 dBm, FMOD = CW
OLP: ABS, Lambdacoupledto OLS, DlSPL
= x.xx
. . DUT Alignment routine
7.6 Callingthe Alignment Routine
- Openthe instrument.
- Set DIP switch S1.2 toON.
- Closethe instrumentagain (no stray light mustenter instrument)
- Turnon by pressingthe PERM key (pressONIOFFkey for >2 s)
- Letthe instrumentwarm up for 5 minutes.
Whenthe instrument isturnedon, it counts downfrom 10to 1 (displayedinthe lambdafield)
andthen goes intothe standardsettingsforthe first alignment step:
Level: -2.00 dBm
Lambda: 1310nm
Status: 1-0 (inmodulationfield)
7.7 Function of the Keys
dBmMlatt Steps 1
- 8: Starts an alignment procedureand buffers results.
Step
9: Stores value inEEPROM
dB1REF Selectsthe next alignment step
<- Select leveldigit
t Selected level digit plus 1
1
Selected leveldigit minus 1
ON/OFF Quitsthe alignment routine
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Service Manual OLP-101-15
Step 8: Temperaturealignment
Step 8 is usedto enter the referencetemperature. The current temperature in "C must be
enteredwith an accuracy of
f 3 "C.
- Enterthe current ambienttemperature in "C by usingthe blue STEP keys.
- Press the [dBmMlatt]key. Value is bufferedin RAM
- Press the [dBIREF] key,go on to next step.
Step 9: Storage
Step 9 is usedto store the datathat have been recordedin EEPROM
- When step 9 is reached,"-S-"is displayed.
- Eachalignment step can be repeated by pressingthe appropriateblue STEP key.
- To quit the alignment routinewithout storingthe alignmentvalues, press the ONIOFFkey.
- Whenthe [dBmMlatt] key is pressed,the alignment data recordedfrom steps 1to 8 are
transferredto the EEPROM.
Status messages
in the modulationfield
9-1 Memory routine running.
9-1
: Successfulalignment, EEPROM has beenoverwritten.
9-E
:
Alignment not possibleor only partialalignment carried out.
Errormessages
in the lambda field (if 9-E appears)
El0: Noalignmentstep has beencarried out successfully.
-> Nostorage possible.
Ell: Only some alignmentshavebeencarriedout.
-> Storage of some alignmentspossible(see below)
El
2:
Linearityalignmentwas incorrector incomplete.
-> Nostoragepossible.
E14: Linearityalignmentout-of-tolerance.
E15: Absolute levelalignment at 850 nm out-of-tolerance.
El
6:
Absolute level alignmentat 1310nmout-of-tolerance.
El7: Absolute levelalignmentat 1550 nm out-of-tolerance.
El
8: Temperature alignment out-of-tolerance.
Noteon
Ell (partial alignment)
The alignmentblocks"lineariiofalignment","absolutealignment"and"temperaturealignment"
do not all haveto becarriedout. One or more blocks may be runprovidedeach block is run
correctly.
- Pressthe [dBmMlatt] key again.
Ifthe status message9-E appearsagain, there is an alignmenterror. Repeatthe affected
alignment steps.
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Service Manual
OW-101-15
Function ChecWConfidence Test
Introduction
The technicaldata of the OLP-10115are stronglywavelength-dependent. Ifthe wavelengths of
the sourcesdifferfromthe nominalwavelengths,the measurementerror of the OLP-101-15may
increase.
The function checwconfidencetest is performedat the wavelengths of 1320 nm, 1550nm and
850 nm.
Preparations
- Ambient conditions: Moderatelab environment,23 OC f 3 "C, no direct illumination(e.g
sunlight).
- Carefullyclean and check the opticalconnectors.
- Performthe dark current adjustment (dustcap on the measurementport,then pressand
holddown the dBmMlatt key. For more information see the operating manual).
Important: The datadeterminedduringdark current adjustment isstoredinvolatile memory.
After switchingoff andthen on againthe dark currentadjustment must be repeated.
Measurement Errors at 1310 nm
The check is carried out at 1310 nm f 2 nm.
Note:The reference measurements usingthe OLP-110are onlyvalid
if thewavelengthsof the
OLSandthe OLP-110are coupled (automaticcorrectionof thewavelengthdependencyfor the
referencemeasurement).
Test setup
OCD BN 2202192.06
Settings
OLS: Lambda
= 1310 nm, level = 0dBm, FMOD = CW
OLA-100: Lambdacoupledto OLS, see below for attenuation
OLP-110: ABS, STD, Lambdacoupledto OLS
FMOD
= CW, BW = 2 HZ, AUTORANGE ON,
DlSPL
= x.xx
OLP-110
K31m
OLS
I
I
K31m
I
OLA-100
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Service Manual OLP-101-15
Settings
OLS: Lambda
= 1550 nm, level = 0 dBm, FMOD = CW
OLA-100: Lambda coupledto OLS, see below for attenuation
OLP-110: ABS, STD, Lambdacoupledto OLS
FMOD
= CW, BW = 2 HZ, AUTORANGE ON,
DlSPL
= x.xx
DUT Lambda = 1550 nm
Measurement
- Carry out the referencemeasurement with the OLP-110at 1550 nmand -3 dBm.
Setthe OLS andthe OLA so that the OLP-110indicates-3.00 dBm.
- Carry out measurementwith the DUT.
- Repeatthe measurementsat -30 dBm and-50 dBm. Forfunction check limits see table
below.
Level
-3dBm
-30dBm
8.5 Measurement Error at 850 nm
OLP-15:
The check is carriedout at 850 nm
+ 2 nm.
Specifiedlimits
f 0.70 dB
f 0.70 dB
Level
-3 dBm
Note: The reference measurementusingthe OLP-110 isonly valid if the wavelengthsof the
OLSandthe OLP-110arecoupled(automatic correctionof thewavelengthdependencyfor the
reference measurement).
Uncertaintyof
measurement
f 0.20 dB
f 0.20 dB
Specified limits
f 0.22 dB
Function check
limits
f 0.90 dB
f 0.90 dB
Uncertaintyof
measurement
f 0.20 dB
Function check
limits
f 0.42 dB
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Service Manual OLP-101-15
Settings
OLS: Lambda = 1310nm, level = 0 dBm, FMOD = CW
OLA-100: Lambdacoupledto OLS, see below for attenuation
DUT: Lambda
= 1310 nm
Measurement
- Set the OLA so that the DUT indicates-20 dBm (approx.).
- Switchon the OLS frequency modulationwith FMOD = 270 Hz, 1kHz and 2 kHz one after
the other.
The DUTshould displaythe frequencies.
- Repeatthe check at -47dBm CW.
Note:With modulatedlight the displayedlevel is
3 dB lowerthan in CW.
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Service Manual OD-101-15
9 Circuit Description
Blockdiagram
Modulation Calibration
detection
Photodiode
P hotodiode
ADC
Processor
Inputcircuit
- system
-
Agermanium photodiodeisusedinthe OLP-10. The Ge diode isidealfor the wavelengths 8201
850
nm and l3OOIl3lO nm. The measurementerror increasesat 1550 nm.
. .
An InGaAs-photodiodeis usedfor the OLP-15. The InGaAsdiode is idealfor the wavelengths
130011310 nm and 1550 nm. The measurementerror increases at 850 nm.
lnput circuit
After the photodiode comes athree-stagetransimpedanceamplifierwhich converts the
photodiodecurrent intoa voltage.
The stages (ranges
1 to 3) are drivenvia U5.2.
The most sensitive stage (range 3) comprises U4.1 and R13. Q5 isconnectedtothe relatively
high-impedanceoutput of
U4.1 andacts as an impedanceconverter. Inrange 3, Q7 ison, but
Q3 and Q6 are off.
The middlestage (range
2) isformed by U4.2 plus Q4 and R9. Q6 is onbut Q3 and Q7 are off.
Inthe higheststage (range
I),R8 is connectedinparallelwith R9 (middle stage).
Therefore, inrange
1, Q3 and Q6 are on, Q7 is off.
The followingare selectedvia multiplexer
U5.1:
Pin 1:
Range 1 or 2
Pin 5: Range 3
Pin 2: Ground
Pin
3:
Temperature voltage (generatedby U7)
The multiplexeroutput feeds the signalviaalowpass (R18, C11) tothe AID converter U8. This
is an integrating
ADC (integrationcapacitor C15) with serialoutput. Itsdrive range (pin 14) is
0 v to 1 v.
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Service Manual OP-1 01-15
Onloff control
The "main switch" of the instrument is U1.2. Q1 is an.auxiliaryon-switch.
When the ONIOFF key is pressed,Q1 is turned on, the DCIDC converter U2 receivescurrent
and starts,the
5 V voltage supply builds up andthe gate array U11 and microcontroller U10
receivea reset.When a reset is detected,the gate array causes line INT2 (U11 PIN 20) to go
high, turning on Q10 and Q9 and so also turning on U1.2. The instrumentis now switchedon.
Ifthe ONIOFF key is helddown, capacitorC3chargesvia R7andQ2. Froma certainlevel(ON1
OFF pressed
> approx. 2 seconds), the gate array detects PERM-IN low at its input (U11 pin
10)and the instrumentgoes into permanent mode. This means:the PERM LED is turned on
andthe instrument's power cut-offfacility disabled.
If the PERM-IN input remains.high (ONIOFF
< approx. 2 s), the instrumentwill turn itself off
automaticallyafter 20 minutes to save the batteries.
Turningoff the instrument:Ifthe ONIOFFkey is pressed, the gate array receivesa pulse viaQ2
and
C4 at input CPFF (U11 pin 11). The INT2 line goes LOW, Q10 turns offafter a delay
(providedby C21), so turningoff Q9 and U1.2 too. The delay givesthe microcontrollertime to
storethe current device settings in EEPROMbeforethe instrumentturns off.
Battery monitoring
ComparatorU6.2 is usedfor battery monitoring.The LOW-EAT signal (pin5) goes low if the
battery voltage goes below 2.2
V. BATis displayedas awarning.
+5 V power supply
The DCIDCconverter U2goes intooperationif the batteryvoltage goes above approx. 2
V and
is designedto operate upto about3.5
V. Q8 and U1.l helpthe DCIDCconverterto start.
-5 V powersupply
The DCIDCconverter U3generates tha -5
V supply from the +5 V supply.
Calibration
EEPROM
All alignments are carried out usingcorrections which are stored inEEPROMU13.
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