Sea Tel Side Exit User manual

Procedure, Field Replacement, Level Cage Kit, Side Exit
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Page1of8
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Document No
135265 Rev B
Copyright © Sea Tel, Inc 2011 - The information contained in this document is proprietary to Sea
Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc. 

1. BriefSummary:
Troubleshootingdocumentfordiagnosingafaultwithandreplacingthelevelcageassembly.
2. Checklist:
VerifyRemoteTilt
VerifyInitialization
VerifySensorOutputsusingDacRemP
AzimuthandRelativeTargeting
DriftandSensorMonitoring
3. TheoryofOperation:
Thelevelcagecontains4sensors,afluidfilledtiltsensorwhichisusedasthesystemshorizonreference(levelposition)
aswellaslongtermstabilizationreference,and3solidstateratesensors;oneforeachaxiswhichactastheantennas
shorttermstabilizationreference.Afaultysensorinsidethelevelcagewillcausetheantennatolosestabilityand
mispointfromthesatelliteunderdynamicconditions.However,thesystemmayappeartobeoperationalintheport
whenthereisnomotiontocounteract.Thisdocumentwillrunthroughtestingthesensorsinsidethelevelcage,
replacingthelevelcageassemblyandcalibratingthesystemsremotetiltsetting.
4. VerifyRemoteTilt:
Ifthepedestalishavingstabilityproblems,firstly,checktheremotetiltsettingbylookingatthelevelbubbleontopof
thelevelcage(note:oldersystemsdidn’thaveabubbleinstalledontopofthelevelcage).Itisonlypossibletodoso
whenthevesselisstationary.Ifthebubbleisn’tasclosetocentralaspossible,theremotetiltsettingisn’tcorrectly
calibratedmeaningtheratesensorswon’tbecorrectlyalignedwiththeiraxis.Thiswillcausetheratesensorstooutput
incorrectfeedbackintothePCU’scontrolloop,potentiallycausingastabilizationissue.Calibratetheremotetiltsetting
aspertheinstructionsattheendofthisdocumentandcontinuetotestthelevelcageusingthefollowprocedures.
5. VerifyInitialization:
Powercyclethepedestal
1. Brakesrelease(ifapplicable)
2. Levelcagedrivestoitsendstopandthenbacksoffexactly45degrees.Elistrackedbasedonstepsissued
bytransistorsinthePCU.
3. Elevationaxisdrivesto45degreesbasedonfeedbackfromthelevelcagestiltsensor.
4. Crosslevelaxisdrivestolevel,againbasedonfeedbackfromthetiltsensor.
5. Unlimitedazimuthsystemsdriveclockwiseuntilthehallaffectsensor/switchseesthehomeflag(magnet
ornotch)ontheAZdrivepulley.
6. Limitedazimuthsystemsdriveclockwiseintotheend‐stopthendrivesCCWawayfromthestop.Ifa
6003A/6004system,theRELwouldatthispointbe580.0degrees.
Ifanyofthesestepsfail,ortheACUreportsmodel"xx03/xx97",theantennasN0parameterneedscalibrating.Once
entered,verifythattheparameterhassavedcorrectlytothePCU’sNVRAM.Amotordriveissueorpedestalerror
requiresfurthertroubleshooting.
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Procedure, Field Replacement, Level Cage Kit, Side Exit
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Document No
135265 Rev B
Copyright © Sea Tel, Inc 2011 - The information contained in this document is proprietary to Sea
Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc. 

6. VerifyStabilization:
Usingthebelowprocedurewewillphysicallymovethesystemsaxisunderstaticconditions,thusintroducinganerror
intothePCU’scontrolloop.Thiswillallowustoverifythatthesystemisabletoreturntoitslevelposition(stabilizeitself)
efficiently.WeareabletomonitorthesensoroutputsonDacRemPtoobservewhatishappening,orwecanjustwatch
thepedestalandobservehowitresponds.
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1. Turndishscanandtrackingoff.SelecttheDISP_VchartofDacRemP;youwillseethecurrentoutputfromthetilt
sensoringraphform.Oncearemotetilthasbeensetandwheninstableconditions,thetraceshouldbestableand
nomorethan+/‐4divisionsfromtheredreferenceline.Ifoutsidethislimitthenre‐checktheremotetiltandthenif
necessary,replaceandre‐calibratethelevelcage.
2. VerifyCrossLevelresponse:
Pushthecrosslevelbeamdowntotheleft(CCW)andholditinposition.VerifythattheCLtraceonDacRemP
movesdownanequalamounttothemovementexertedontheaxis.ReleasetheCLbeamandverifythatthe
DacRemPtracereturnsbacktoitsoriginalposition,withoutdeviatingortakingtimetosettle.Nowpushthecross
levelbeamdowntotherightandholditinposition.ThistimeverifythattheCLtraceonDacRemPmovesupan
equalamounttothemovementexertedontheaxis.ReleasetheAxisandverifytheDacRemPtraceandcrosslevel
beamreturnbacktotheiroriginalpositions,withoutdeviatingortakingtimetosettle.
3. VerifyLevel(Elevation)response:
PushthereflectorupinElevationandholditinposition.VerifythattheLVtraceonDacRemPmovesdownanequal
amounttothemovementexertedontheaxis.ReleasetheaxisandverifytheDacRemPtracereturns(orthe
systemsaxisreturns)backtoitsoriginalposition,withoutdeviatingortakingtimetosettle.Pushthereflectordown
inelevationandholditinposition.VerifythattheLVtraceonDacRemPmovesupanequalamounttothe
movementexertedontheaxis.ReleasetheaxisandverifytheDacRemPtracereturns(orthesystemsaxisreturns)
backtoitsoriginalposition,withoutdeviatingortakingtimetosettle.
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IfusingDacRemPthetraceshouldlooksimilartotheimagetotheleft.Notehowaftereachmovementthesystem
returnstoitslevelpositionefficientlywithouttakingtimetosettle.
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Procedure, Field Replacement, Level Cage Kit, Side Exit

Page3of8

Document No
135265 Rev B
Copyright © Sea Tel, Inc 2011 - The information contained in this document is proprietary to Sea
Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc. 

7. RateSensorMonitoring:
RatesensoroutputscanalsobemonitoredusingtheDISP_WscreenofDacRemPtoverifyanydeviationsunderstatic
conditions.Thetracesshouldremainconsistent.Anydriftingorspikesareanindicationthesensorsvoltageoutputis
changingandthesensorisdefective(providednoforcesarebeingexertedonthesystem).Normaltraceis+/‐1division
fromredline.
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8. AzimuthTargeting:
Shouldtheantennahaveissuestargetinginazimuth,suchasnotaccuratelyfindingthesatelliteorrepeatedlyfindingthe
satelliteindifferentazimuthpositions,thenit’simportanttodiagnoseifthesystemismispointinginazimuthorrelative.
RelativefeedbackfromtheAZencodercanbeverifiedbyinitializingthesystem,verifyingitcalibratesitselfcorrectlyand
thendrivingthepedestalclockwisein90degreeincrementsovera360degreerotation.Makenotethatthesystem
pointscorrectly(bow,starboard,aft,port,bowandstarboard)andthatnoAZreferenceerrorisflaggedbythePCU.A
mechanicalproblemsuchasthebeltslippingonthepulleycouldalsocausethiskindoferror,ascouldsomeother
mechanicalissue.Skewingtheantennainazimuthbyholdingtherightorleftarrowkeytodrivetheantennaslowlymay
alsopresentanissue.
Ifthesystemkeepsfindingthesatelliteatdifferentazimuthpositionsbutatthesamerelative,theencoderisfunctioning
correctlyandoneofthereferenceinputs(Levelcage,gyro)tothePCUiscausingtheantennatomispoint.
9. Drift:
Anotherfailurewhichcanoccurisifaratesensorstartsdrifting;thismeansthesensorsvoltageoutputdeviatesfrom
whatthePCUisexpectingunderstablecondition(2.50VDC).Thisfaultwillintroduceanerrorintothecontrolloop.Itis
morecommontoseethisintheAzimuthaxisastheCLandELaxishavethetiltsensorastheirlongtermreference
(althoughshouldtheratesensorsdriftbelargeenoughtooverpowerthetiltsensoryouwouldseethesystemdriving
intooneoftheCLorELendstops).Thisismorenoticeablewithtrackingturnedoff.
ToverifyifthesystemisdriftinginAzimuth,firstturnofftrackingandthenmonitortherelativeposition.Understatic
conditions(thevesselsheadingisn’tchanging)therelativeshouldremainstill.Iftherelativevaluebeginsto
increase/decreasefromitsnominalpositionthentheazimuthratesensorisdrifting,creatinganerrorintothePCU’s
controlloop.ThiswillcausethePCUtobelievethevesselsheadingischangingandinturndrivetheazimuthaxisinthe
oppositedirectiontocompensate. 

Procedure, Field Replacement, Level Cage Kit, Side Exit
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Document No
135265 Rev B
Copyright © Sea Tel, Inc 2011 - The information contained in this document is proprietary to Sea
Tel, Inc.. This document may not be reproduced or distributed in any form without prior written
consent of Sea Tel, Inc. 

10. Diagnostics:
Anyincorrectreadingsfromtheabovetestswouldrelatetoanerrorintheantennascontrolloopcausingthesystemto
notstabilizecorrectly.Themostlikelycauseofthisisadefectivesensorinthelevelcage.Thenextstepwouldbeto
replaceandre‐calibratethelevelcage.Nowrepeatthefailedtesttoverifythatthesystemisnowfunctioningcorrectly.
Shouldtheproblemremain,anotherpossiblecausemaybeafaultwiththereferenceharnessbetweenthelevelcage
andPCU.ThePCUitselfshouldnotberuledoutasfaultyeither.Evenso,thelevelcageisthemostlikelycomponentto
becausingthisissue,thereforereplacingitisthefirststepwhentroubleshooting.
Oncetheproblemhasbeenrectified,itisgoodpracticetorefittheoriginallevelcageandseeifthefaultreturns.Itis
possiblethatcorrosiononthepinsofthereferenceharnessand/orconnectorsofthePCU/levelcagecausedtheinitial
fault.Byconnectingthereplacementlevelcage,itislikelythatanypincorrosionmayhaverubbedoff,creatingacleaner
electricalcontact.Youmayhavebeenundertheimpressionthatreplacingthelevelcagerectifiedthefaultwhenin
actualfact;theissuewasapoorelectricalcontactcausingvaryingresistance.
11. FurtherInformation:
Shouldthesystemfailtotargetthecorrectelevation(physicallypointingatadifferentpositiontothereadingonthe
DAC),orhaveissuesdrivingpastacertainelevationpositionthenthemostlikelycauseisadefectivelevelcagemotor.
Ifthesystemisdisplayingapedestalerror(error8),thereisadriveissuewiththeantennaandattentionwillneedtobe
paidtothemotorandmotordriver(servoamp)fortherelevantaxis.Thereisnoerrorcodethatdirectlytellsyouifthe
levelcageorlevelcagesteppermotorhasfailed,however,apointingorstabilizationissueisagoodindication.
Anotherpotentialissuewhichcouldcausetheantennatolosethesatelliteisifthevesselsgyrocompassisdrifting.This
accumulatingerroristhenfedintothecontrolloop.ThiscanbeverifiedbyrunningaDacRemPlogfileatseatomonitor
thepedestalsreadingswhentheAGCdrops,orbyputtingthesystemintosatellitereferencemodetouncouplethegyro
feedfromtheazimuthstabilizationloop.


Procedure, Field Replacement, Level Cage Kit, Side Exit
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consent of Sea Tel, Inc. 

12. ReplacingtheLevelCageAssembly:
12.1. Tools.

2mmFlatBlade(Terminal)Screwdriver
#1PhillipsScrewdriver
½”Wrench/Spanner

12.2. Procedure.
Procedureforreplacingthelevelcageassembly,SeaTelkitpartnumber:135344(levelcageassemblypartnumber:
122208‐1)andtensioningthelevelcagebelt.

*CAUTION:Powerdownthepedestalbeforefollowingthis
procedure.
1.Usinga2mmflatbladescrewdriver,loosenthescrews
securingthereferenceharnessD‐Subconnectortolevelcage.


2.Usinga#1Phillipsscrewdriver,loosenthefourscrews
attachinglevelcagemotortotheELpan(donotfully
remove).




3.Usinga½”socketorspanner,removetheNylocknut
securingthelevelcagetothespindle.


Procedure, Field Replacement, Level Cage Kit, Side Exit
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consent of Sea Tel, Inc. 
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
4.Slidethemotortowardsthelevelcagetoallowenoughslack
onthebelttoremoveitwithoutstressingit.
5.Removethedefectivelevelcage,takingcarenottoremove
thestandoffspacerfromthespindle.


6.Installthereplacementlevelcageontothespindle,slipping
thebeltoverthelevelcagepulleyandmakingsureitsend
stopsarealignedcorrectly.
7.Secureitwiththe1/2”Nylocknut.Whentight(sothatthere
isnohorizontalplayalongthespindle)addanadditional½a
turnforagoodground.Rotatethelevelcagebyhandand
verifyithas90degreesofmotionandthatthecagerotates
freely,ensuringthestopsdonotrubagainsttheELpan.


8.Tensionthebeltbyslidingthemotorassemblybyhand
awayfromlevelcageandthentightenthefourscrews.




9.Acorrectlytensionedbeltwillallow¼turnwithyourfingers.
Ifthebelttensionistootight/looseadjustuntilcorrect.
10.Ifthebelttensionisincorrectloosenthescrewsandre‐
tension.NoLoctiteisrequiredaslockwashersareusedonthe
securingscrews.
11.Re‐connectthereferenceharnesstothelevelcageand
tightentheretainingscrews,againnoneedtouseLoctiteas
lockwashersareinstalledontheconnectorshell.



Procedure, Field Replacement, Level Cage Kit, Side Exit
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
13. CalibratingtheRemoteTiltSetting:
Thisprocedureisrequiredtocalibratethelevelcagesothatallthesensorswillbeaccuratelyalignedtotheiraxis.The
fluidfilledtiltsensorprovidesatwodimensionalhorizonreference.Thesystemisnotabletoautomaticallycalculatethe
exactcentervalue,thereforeitisnecessarytoperformthisproceduretomanuallyenteranyoffsetrequiredtomakesure
thePCUreceivesatruehorizonreference.

1. Turndishscanoff:
EnterintotheSetupMenubypressingandholdingthearrowstogetheruntiltheELTrimorAutoTrim
parameterisdisplayed.
Usethearrowkeytoscrollthroughthemenuuntilthedishscanwindowisdisplayed.
Pressthearrowtoactivatethewindowandthenpressthearrow,followedbythebuttontoturn
dishscanfromontooff.
*Note:Whenyoupressthearrowtoturndishscanoffyouwon’tseethedisplaychangeuntilyoupressthe
button.

(Steps2‐7requiresassistancetoobserveandoperateantennasimultaneously)

2. EnterintotheSetupMenubypressingandholdingthearrowstogetheruntiltheELTrimorAutoTrim
parameterisdisplayed.

3. PushthearrowkeyuntiltheRemoteTiltwindowisdisplayed.

4. PushthearrowkeytoactivatetheRemoteTiltsetting.

5. Usethearrowkeystopositionthebubbleasclosetothecenteraspossible.Eachpressofanarrowkeyonthe
directionalpadwillmovetheRemoteTilt½adegree.Itisadvisedthatyouonlypressthebuttononceandwaitfor
theaxistomovebeforepressingitagain.

Whenstandingbehindtheantennalookingatthebubble,ifthebubbleisovertotheright,youneedtopressthe
(right)arrowtobringthebubbleintothecenter.Ifthebubbleisdowntowardsyou,youneedtopressthe
(down)arrowtobringittowardsthecenter.Ifthebubbleistotheleft,youneedtopressthe(left)arrowandif
thebubbleisuptowardsthetop,youneedpressthe(up)arrowtomoveittowardsthecenter.


Procedure, Field Replacement, Level Cage Kit, Side Exit
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consent of Sea Tel, Inc. 

Whencorrectthebubbleshouldbeasclosetothecenterofthefluidaspossible


6. WhenthebubbleisascentralaspossiblepressthebuttontodeactivatetheRemoteTiltsetting.

7. Turndishscanon:
EnterintotheSetupMenubypressingandholdingthearrowsuntileithertheELTrimorAutoTrim
parameterisdisplayed.
Usethearrowkeytoscrollthroughthemenuuntilthedishscanwindowisdisplayed.
Pressthearrowkeytoactivatethewindowandthenpressthearrowkey,followedbythebuttonto
turndishscanfromofftoon.
*Note:Whenyoupressthearrowtoturndishscanonyouwon’tseethedisplaychangeuntilyoupressthe
button.

8. SavetheRemoteTiltsettinginthePCU:
PressthearrowkeyuntiltheRemoteParameterswindowisdisplayed.
Pressthearrowkeytoactivatethewindowfollowedbythebutton(you’llseeaconfirmationonthe
displaysaying“Saved”).

9. AsgoodpracticemakeanoteofyourN4andN5parametersonceyouhavecorrectlysettheremotetilt.TheN4and
N5parametersareanumericreadoftheremotetilt.Todothisgototheremotecommandwindowandkeyin
N4999toreadtheCLsetting,followedbyN5999toreadtheELsetting.

