Specifications

Masterclock, Inc.

phone(USAandCanada):1‐800‐940‐2248|phone(international):+1‐636‐724‐3666
email:[e-mail]|online:www.masterclock.com











1.1SCOPE
ThisdocumentspecifiesawiredclocksystemthatreliesontheaccuracyoftheGlobalPositioningSatellite(GPS)system
forsynchronizingthetimeprovidedtoclocksandnetworkdevicesusingtheNetworkTimeProtocol(NTP).Suchaclock
systemreliesononeormoreNTPtimeserverswithan
integratedGPSreceiver,toactasmasterclocksandvirtuallyan
unlimitednumberofnetworkclockdisplaysactingasclientdevices.Inaddition,othernetworkclientdevicescanbenefit
fromtheavailabilityoftheNTPtimeservers.DataandlowvoltageDCpowercanbedistributedoverthesamenetwork
cableusing
PoweroverEthernettechnology,resultinginsignificantcostsavings.Thelimitationsareprimarilynetwork
configurationandimplementationbased,asthesystemcanbeaddedtoanexistingnetworkorconfiguredasan
independentnetworktosimplyprovideasynchronizedclockdisplaysystem.

1.2GENERAL
NTP(NetworkTimeProtocol)serversallowclients
tosynchronizeclocks,bells,computerclocks,othercomputertiming
devicesandotherkindsofnetworkequipmentusingastandardreferenceoftimeacceptedworldwide,knownasUTC
(UniversalTimeCoordinated).NTPserverswithanintegratedGPSreceiverlocatedonaLAN(LocalAreaNetwork)can
providethehighaccuracyof
theGPSsatellitesystemtoprovidetheUTCreferencetime,eliminatingtheneedtoreceive
timefromaNTPserverlocatedontheInternet.PlacingoneormoreNTPonyourlocalnetworkbehindafacilityfirewall
enhancesreliability,redundancy,accuracy,andsecurity.

UsingNTPisclearlyanadvantagesince
itpermitsautomaticsynchronizationofalltheequipmenthookeduptothe
network,thusreducingtheneedandassociatedcostforpersonneltotraveltoremoteclocklocationstosetthetime
manually.Ingeneral,ithasbeenobservedthatsincetherecentintroductionofNTPasastandardfornetwork
synchronization,
clockinstallationshavebecomeeasier,bettersynchronized,morereliable,andprovideatraceablesource
oftimeforcriticalnetworkfunctions,resultinginloweroverallcost.

NTPprovidesasimplifiedprotocolcalledSNTP(SimplifiedNetworkTimeProtocol),whichclientscanutilizetosetthetime
totrustedNTPtimeservers.SNTPV4
isasubsetofthefullNTPV3versionandiswidelyacceptedforclientdevices.

InformationForaGPSSynchronizedClockSystemusingNetworkTimeProtocolandPoweroverEthernet

POE(PoweroverEthernet)isarecognizedandagrowingmethodofsignificantlyreducinginstallationcostsandproviding
low
voltageDCpowertonetworkdevicesbydistributingpowerovertheunusedpairofstandardnetworkcables.The
modestincrementalcostofpurchasingPOEequipmentthatiscomplianttotheIEEE802.3afstandard,dramaticallyoffsets
theinstallationcostsandsafetyissuesassociatedwithutilizinganddistributingACpower.AGPS
Synchronizedclock
systemusingNTPandPOEoffersignificantinstallationandmaintenancecostbenefitsovertraditionalclocksystems.

2.1GENERALSYSTEMREQUIRMENTS
Thesynchronizedclocksystemshallmeetorexceedtherequirementsofthisspecificationinallaspects.

2.2OPERATIONALREQUIREMENTSANDENVIRONMENTALSPECIFICATIONS
Theclocksystemshallbelocated
andoperatedinanindoorenvironment,withintheparametersofastandardnetwork
configuration,andutilizingstandardindustryprovidednetworkequipmentanddistributionmethods,including
standardizedPOEdistributiontechnology.Theclocksystemshalloperateautonomouslyandprovidesoftware
configurationoptionsfortimezoneoffsets,automaticdaylightsavingtimecorrectionswithout
scheduledoperator
interventionormaintenance.Theclocksystemshallbeconfiguredviasoftwarecontrolandshallallowforremote
monitoringandconfigurationchangeswhileprovidingpasswordprotection.

Environmentalspecifications
Thesystemshalloperateunderthefollowingenvironmentalconditions:
•OperatingRange:32°Fto122°F(0°Cto50°
C)
•StorageRange:‐40°Fto70°F(‐40°Cto70°C)
•RelativeHumidity:0‐90%,non‐condensing

Compliancespecifications
Allequipmentshallbetested,labeledandcertifiedbyanationallyrecognizedandapprovedtestinglaboratorytomeetthe
followinglowvoltagesafetyandelectromagneticcompliancerequirements
oftheUnitedStatesandEuropeanUnion.
•FCC,part15,ClassBlimitsforradiatedandlineconductedemissions
•ElectromagneticCompatibility89/336/EEC;92/31/EC;93/68/EEC;2004/108/EC
•Lowvoltagedirective2006/95/EC

2.3CLOCKENGINEERINGREQUIRMENTSANDPERFORMANCE
Thenetworkclocksshallmeetthefollowingengineeringandperformancerequirements.


10.2
Information
Suggested Functional Specs