GlobalTime Electronic GTT-030 User manual

GlobalTimeNTPProducts
UsermanualofGTT-030
1
Catalog
Catalog 1
Chapter1Basicinformationandpackaging 02
1.1Keyfeatures 02
1.2Packaging 02
1.3Outline 02
1.4Thedevicedescription 03
Chapter2Hardwareinstallationandcommissioning 04
2.1Thedevicestructure 04
2.2Outdoorinstallation 04
2.3Indoorinstallation 06
Chapter3EquipmentMaintenance 07
3.1Indicatorstate 07
3.2ServerConfigurationDebugging 07
3.2.1UserLogin 08
3.2.2Viewthenetworkstatus 09
3.2.3Changenetworksetting 09
3.2.4Displaythestatus 10
3.2.5Chagethepassword 10
3.2.6Exit 11
3.2.7Timeserverlogonthroughthenetwork 11
3.3Remotedial-upmaintenance 11
3.4ClientConfiguration 12
3.5Troubleshooting 13
3.5.1Allindicatorlightsareoffwhenpowerison 13
3.5.2Receivingnosatellitesignalsforalongterm 13
3.5.3Cannotpingthetimeserverafterconfiguration 14
3.5.4Instabilitystateofreceivingsatellitesignal/theequipmentisinholdmode 14
3.5.5Theclientcannotreceivetimingservice 14
3.5.6Howtoconfigurethenetworkequipmenttoreceivetimeservice 15
Chapter4Detailedperformanceindexoftheequipment 16
Chapter5Appendix 17

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Chapter1Basicinformationandpackaging
GTT-030networktimeserveristheprofessionalnetworkequipment,providinghighly-stabletimesource.
GTT-030networktimeserverreceivesGPSsatellitesignalsandextractsthetiminginformationtoadjust
theserver'slocaltime.ItdistributesstandardtimeviaNTPprotocol(NetworkTimeProtocol).Uponthe
PCorserverwhichneedtimesynchronizationservices,aclientprogramwillreadtheNTPprotocol,
derivetimeinformation,andmodifythetimeofrelatedequipment.Thenetworktimeserveriswidely
usedintelecommunications,finance,taxation,publicsecurityandotherspecialnetworkaswellas
commoncorporatenetworktounifythenetworktime.
1.1 Keyfeatures
lReceiveGPSsatellitesignalsorthedual-satellitesignalofGPSandGLONASS(optional)
lAdoptRFC1119/1305NTPprotocol(NetworkTimeProtocol)todeliverytime
lSupportRFC1769/2030SNTPprotocol(SimpleNetworkTimeProtocol)
lDifferentclientprogramssupportWindows98/2000/NT/XP,Linux,Unix,FreeBSDandother
operatingsystems,toadapttodifferentapplications
l10/100MBaseTadaptivenetworkinterface
lWaysofmaintenance:thelocalmaintenanceserialport;remotelogin;remotedial-up.
l2lampsdisplaythedeviceworkingstatus
1.2 Packaging
Pleasechecktheshippingpackagewhichshouldcontainthefollowingitems:
(1)GTT-030networktimeserver
(2)Powercable
(3)1metercable
(4)racksetscrews
(5)GPSsatellitereceivingantenna
(6)Antennacable
(7)Antennafixedaccessories
(8)Theusermanual
(9)ThesoftwareCD
(10)ThepackingList
1.3 Outline
Withtherapiddevelopmentofmodernsociety,higherdemandonthetimeprecisionandfrequencyis
putontheagenda.Nowadayswiththedevelopmentofmoderndigitalcommunicationnetworksandthe
informationsuperhighwayconstruction,thepolitical,cultural,technologicalandsocialinformation
coordinationisbasedonastrictsystemoftimesynchronization,especiallyinthecommunications,
electricity,financialsecurities,computernetworks,productionlineoperation,administrationandnational
defenseandotherfieldsurgentlyneedthetimesynchronizationequipment.

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GlobalPositioningSatellite(GPS)signalsactasthereferencesourceofGTT-030networktimeserver.
ThetimereferencecontainedintheGPSsatellitesignalssynchronizeswiththeuniversaltime
coordinated(UTC).Thelong-termfrequencystabilityhasachievedthe10-13levelofmagnitudeof
cesiumatomicclock,whichisequivalenttobeonly1secondslowerduring30years.Toadjustlocaltime
withthisreferencesignalcaneliminatetheaccumulationofdeviationresultedfromthelowaccuracyof
localclocktimeandalsocangreatlyimprovethetimingprecisionoftheserver.GTT-030networktime
serveruseaprofessional12-channelGPSreceiver.Itcanreceiveandlockthesatellitesignalfastand
reliably.
NTPprotocol(NetworkTimeProtocol)isacommoninternationalnetworktimingprotocol.Itsprincipleis
throughtheclienttolaunchatimepollingtotheserverafteranintervaloftime.Accordingtoacertain
filteringalgorithmitcancalculatethetimedeviationbetweentheserverandtheclientaswellasthe
propagationdelaycausedbynetworktransmission.Thenaccordingtothesetwoparameterstoadjust
theclient'slocaltimeandmakeitconsistentwiththeserver.Comparedtoothertimecalibration
prorocols,NTPprotocolcaneliminatetheimpactcausedbynetworktransmissiondelay,soitcan
providehigh-precisiontimingservices.Detaileddescriptioncanbereferredtothelatestprotocol
standardsdocumentsRFC1305andRFC2030.GTT-030networktimeservercanbecompatiblewith
NTPv2/v3/v4invariousversions.
1.4 Thedevicedescription
Figure1-1Thefrontpaneldescription
lThefrontpanelisasshownabove.Theinterfacefunctionsareasfollows:
lmonitoring:localmonitoringserialport,DB9publicoutlet,RS232electricallevel
lNetwork:10/100MBase-Tadaptivenetworkport,RJ45connector
l2Indicatorlights:oneindicatesthepowerwhiletheotherindicatesthestatus,bothofthem
indicatethedeviceworkingstate
Figure1-2Thebackpaneldescription

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Thebackpanelisasshownabove.Thereisapowersocketwithafuseonthebackpanel.Afteropening
thefusebase,thereareaprimaryandareversefusewithspecificationof0.5Aoneachsidetofacilitate
users replacement.Inaddition,thereisalsoanantennaplugaswellas50ohmBNCSocket.
Chapter2Hardwareinstallationandcommissioning
2.1 Thedevicestructure
Figure2-1DeviceStructure
GTT-030networktimeserverconsistsoftheoutdoorpartandinteriorpart.Theoutdoorpartis
composedoftheGPSsatellitereceivingantenna,surgearresterandantennaamplifier(optional).The
functionistocompletethereceptionofsatellitesignals.
TheinteriorpartisthemasterdeviceofGTT-030networktimeservertocompletethefunctionsofthe
satellitesignaldemodulation,thelocalclockcalibration,achievingNTPprotocolandsoon.Itprovides
NTPtimingservicetoothernetworkequipmentbymeansof10/100MBase-Tadaptivenetworkports.
Thefollowingarethedetailinstallationdescriptionoftheoutdoorpartandtheinteriorpart.
2.2O
utdoorinstallation
TheoutdoorpartconsistsoftheGPSsatellitereceivingantenna,surgearresters,transmissioncables
andantennaamplifier.Theinstallationattentionsareasfollows:
Atfirst,theantennainstallationlocationneedstobecarefullyselected,whichwillsignigicantlyinfluence
theequipmentworking.Theantennashouldbeinstalledinhighplacesandcannotbeblocked,suchas
theroof,opentop,etc.Ifyouwanttoachievebetterresults,you dbetterkeeptheelevationangleof15
degreesnotblocked.ItisuselesstoinstalltheantennainsidetheroombecauseGPSsatellitesignalis
veryweakandcannotbereceivedindoors.Itisnomatteriftherearetreesorplasticrainshelterblocked
abovetheantenna,butotherblockwillinfluencethesignalsignificantly.Infact,onlyabookabovethe
antennacancompletelyblockoutthesatellitesignal.
GPSreceiving
antenna
Antennaamplifier
Lightingarrester
GTT-030

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Antennainstallationshouldbelowerthanthelightningrodorotherconstructionsthatcanattract
thunderstrokeandtheinstallationlocationshouldbetterbe10-15metersawayfromthem.GPSantenna
itselfisrarelystruckbythunderblotbutisoftendamagedbythestonginducedelectricfieldresultedfrom
thestuckbuildings(thelightningrod,tower,etc)around.Inthiscircumstance,weshouldinstallthe
arresterinthecable.Normallythearresterwillbeinstalledneartheequipment.Tomakesurethatthe
arrestercanbewellearthed,thearrestershouldbeinstalledbetweenthefeederandtheequipment.
Thenleadthegroundingwirefromthearresterandconnectittotheearth.Theearthresistanceshould
beunder4ohmandmustbefirmlyconnectedtoensurethereliabledischargebylightning.
Sometimestheantennacanbeinstalledoutsidethewindow,butthebuildingmustbelocatedinthe
openfieldswithnocorner.Inthisway,itcanreceiveatleasthalfofthesatellitesignal.Butasa
long-termusingequipment,itisrecommendedthattheantennaisinstalledinhighplaces,whilethe
outsideinstallationcanbeonlyadoptedasatemporarytest.
Thehigh-powermicrowavetransmittingofthesamebandcannotbearoundwheretheGPSantennais
installed.Inaddition,weshouldtrytoavoidtheGPSantennafromthedirectirradiationofhigh-power
electromagneticradiation.
Ifthelengthofthefeederislessthan100meters,theantennaandequipmentcanbedirectlyconnected;
between100metersto200meters,onemorelineamplifierisneeded;rangingfrom200metersto300
meters,twomoreamplifiersareneeded.Ifyouneedlongerfeederlinks,pleasecontactus,GlobalTime
ElectronicCo.,Ltd.Wewillprovidethespecialprogramtoyou.Thefeederusuallyadopt1/2inchRF
cablewhoselossis12.8dB/100mfromtheUnitedStatesAndrew's.
Theprimaryconsiderationswhensettingupthefeeder:
1.Donotbendtoomuch,becauseitwillresultinabrokenfeederconductor.
2.Whenweconnectthefeederintotheinterior,itshouldbebentintoU-shapetopreventInthe
feedershouldbebentintotheinteriorU-,topreventwaterfromflowingbackward.
YoucanuseGPSsignaltranspondertoleadthesignaltotheinterior.Generallyspeaking,GPSsignals
canbewellreceivedwithin5mofthetransponderantenna.Becauseofthewayofforwarding,itismuch
effectiveforthepreventionoflightningandtheprotectionofthehost.Problemscausedbythelightning
isthetransponderdamaged.Duetoacertaintransmittingpower,itissuitableforsomeoccasions.

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Table2-1AntennaSpecifications
Frequencyrange1575±5MHz;RFconnectorN-typeconnectors
Polarization Right-hand
circularpolarization Installation Thread(M24 ×1.5) connection
Antennagain ≥3.5dB；Volume φ96×126mm；
Amplifiergain ≥37dB；Operating
temperature -45 ～85 ；
Noisecoefficient ≤1.5dB；Storage
temperature -50 ～90 ；
Interference
suppression 25dB(f0±100MHz)；Humidity 0～100%
Powerconsumption 3V×20mA；
2.3Indoorinstallation
Afterconnecting220VACtothemasterdevice,theindicatorlight"Power"onthefrontpanelshouldbe
litandindicatethattherunningofpowersupplyisnormal.Thenthestatuslightstartstobeyellow(red
andgreen)andestinguishesin1minute.IfGPSreceiverisingoodrunning,itwillturngreenabout15
minuteslaterandthesystemstartstoworknormally.TomeasuretheBNCantennasocketwitha
mutimeter,thefeedvoltageshouldbeupto5V.Thenconnecttheantennacablewiththeantennasocket.
Next,useacomputertopassthroughtheIPaddressandnetworksettingsoftheserialportconfiguration
timeserver,saveandexit,thenrestartGTT-030Networktimeservertomakethenetworksettingstake
effect.Afterreboot,inputtheIPaddressofthePINGserverinanothercomputertocheckthenetwork
settingscorrectornot.ThenlogonthenetworktimeserverfromSSHclienttoobservethesatellite
receivingstate,theinformationontimetrackingstateoftheserverandsoon.Whentheserverlocksthe
satellitetime(Theindicatorlightonthepanelturnsgreen),GTT-030startstoprovidetimeinformation
tootherclientswithinthenetwork.Thespecificprocessofsoftwareconfigurationcanrefertothe
followingchapter.

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Chapter3EquipmentMaintenance
3.1Indicatorstate
Table3-2IndicatorStatus
IndicatorStatusDescription
Powersupply onThepowersupplyisnormal
offThepowersupplyisabnormal
State
offTheserverisunlock
orange Theserverisinthemaintainingstateandcannot trackthesatellite,buttheoutputtimeoftheserver
isstillavailable
greenTheserverisinthenormaltrackingstate
3.2Serverconfigurationdebugging
GTT-030networktimeservercanconductmaintenanceandmanagementthroughthelocalserialcable
connectionortheremotetelnetconnection.Thelocalconnectionneedstouseacrossserialcablewith
connectorsonbothsides(thatis,2,3feetofthetwosidesarecrossconnected).Themanagementis
carriedoutonthesuperterminal.Theserialportconfigurationparametersofthesuperterminalareas
showninFigure3-1.Undertheremotetelnetconnection,youonlyneedtoenter:telnet<IPaddressof
theserver>underthecommand-line.Thefollowingexampledescribesthemaintenancemethodswith
localconnection,sodoesremotemaintenance.

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Figure3-1TerminalserialportDebuggingsettings
3.2.1UserLogin
Afterconnectingthehyperterminal,pressENTERandyouwillseetheloginscreenjustlike0.Then
entertheusername"ntpuser"andthepassword"Users.".
Note:Payattentiontothelast".".Whenyouhaveloginin,youcansetyourownpassword.
Loginwindow
Afterloggingin,therewillbeainterface,suchas0configurationinterface.Therearetotally5choices:
viewthenetworkstatus,changenetworksetting,displaythestatus,changethepasswordandexit.The
detaileddescriptionofeachfunctionisintroducedasfollow.

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themainconfigurationwindow
3.2.2Viewthenetworkstatus
networkconfigurationwindow
Press"2ENTER"andthepresentnetworksettingwillbedisplayed,includingIPaddress,subnetmask
andgateway.Ifyouenter"y",itwillreturntothepreviousmenu.
3.2.3Changenetworksetting
Whenyoupress"2ENTER"inthemainconfigurationinterface,initiallyitwillaskwhethertouseDHCP
protocoltoassignIPaddress.IfyouwouldliketouseDHCPprotocoltoassignIPaddress,thenselect
"Y".Otherwise,select"N".GTT-030supportgettingIPaddressthroughDHCP,butitalwaysneeda
staticIPaddressbecausetheserverneedstosupplythenetworktimingservicetootherdevices.Asa
result,inDHCPnetworksystem,therecommendedconfigurationistoassignastaticIPaddressfrom
theIPPoolofDHCPservertoGTT-030.OtherdevicescanusethestaticIPtoaccessGTT-030.
WhenitaskswhethertouseDHCP,Ifyouselect"N",itwillprompttoentertheserverIPaddress,subnet
maskandgatewayIPaddress.Finallyitwillpromptwhethertomodifythenetworkconfigurationin
accordancewithsettingsentered,thenselect"Y"anditwillchangetheequipmentconfiguration.This
configurationcannottakeeffectuntilrebootingtheserver.Soweneedtorestarttheserver.Wecan
modifythenetworkconfigurationformanytimesbeforerestartingtheequipment,butonlythelastone
cantakeeffect.TheconfigurationinterfaceisshowninFigure4.
Figure3-2Thenetworkparametersconfigurationinterface

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Note:Whenitdisplays"Pleaserestartthemachinetomakethechangeactive.",press"ENTER"to
returntothepreviousinterface.Thenselect"4Exit",thesettingcantakeeffect.Ifdirectlyturnoffthe
computer,itwillresultintheconfigurationfailed.
3.2.4Displaythestatus
Byentering"3"inthemainconfigurationinterface,youwillenterthe"checktheworkstatus"interface
showninFigure3-3.Thefigureshowsthatthecurrenttimeofthetimeserverisoflevel1.Thetimeroot
deviationis19.487msandthecurrentUTCtimeis1:38:40.Thereare10satelliteswhichcanbetracked
inthesky.Note:thetimeshownisUTCtime,whichdiffersby8hoursfromChinaStandardTime(China
timezoneis+8).Entering"Q"willreturntothemainconfigurationscreenwhileenteringotherkeyswill
continuetothenextstep.WhenGTT-030networktimeserverworkproperly,thetimelevelis1,orelseit
is16.
Figure3-3Checktheworkstatus
3.2.5Chagethepassword
Iftype"4"inthemainconfigurationinterface,itwillenterintothe"changepassword"screen,shownas0.
Atfirst,youneedtotypetheoriginalpassword.Ifcorrect,itwillprompttotypeanewpassword.Theuser
passwordcontains5-8characters.Note:thepasswordcannotbetoosimple.Iftakesomemeaningful
wordsasthepassword,itwillprobablyberefusedbythesystem.Sothepasswordwithcombinationsof
upper-andlower-casestringsisappropriate.
Changethepassword