Masterclock GMR5000 User Manual

MasterclockGMRUse
rManualv2–2016.12
57
DelayMechanism
DelayMechanismisthemethodusedtocalculatethenetworkpathdelays.Alldevicesonthenetworkmustuse
thesamedelaymechanism(eveniftheyareindifferentPTPdomains).EndToEnd(E2E)onlyrequiresthemaster
andslavetosupportPTP.ItdoesnotrequirethenetworkinfrastructuretosupportPTP
.Iftheintervening
infrastructureofthelocalnetworkdoesnotsupportPTP,accuraciesof20‐100microsecondscantypicallybe
achieved.IftheinterveningnetworkdevicesdoessupportE2EPTP(i.e.atransparentclock)sub‐microsecond
accuraciescanbeachieved.PeerToPeer(P2P)reducestheoverallnetworktrafficandcanim
provetheaccuracy
comparedtheE2E,butallofthenetworkinfrastructuremustsupporttheP2Pdelaymechanism.
Synchronizationmode
Twomethodsareavailableforsendingtimestampsacrossthenetwork,OneStepandTwoStep.Assumingall
networkdevicesdotheirtimestampinginhardware(ingen
eralthisshouldbetrue,andistrueforallMasterclock
equipment)bothmethodswillgiveanaccuratetime.IftherearealargenumberofPTPdevices,OneStepis
preferredbecauseitrequiresfewerpackets.
AnnounceInterval
AnnounceintervalspecifiesthetimeintervalbetweensuccessiveAnnouncemessages.TheAnnouncemessageis
usedbythedevicesonthenetworktodeterminewhichdeviceshouldbethegrandmaster.Typically,avalueof1
or2secondsisrecommended.
SyncInterval
SyncIntervalspecifieshowoftenthegrandmastersendsaSyncmessagewhichstartstheprocessofupdatingthe
timeinaPTPslave.Typically,avalueof1or2secondsisrecommended.
TosetPTPbacktodefaults,clickthe“SetPTPtodefaultsandrebootbutton”.Answering‘yes’willperf
ormthe
actionandtheGMR1000/GMR5000willautomaticallyreboot.Afterrebooting,itwilltakeapproximately30
secondsbeforetherebootprocessiscompleted.Ifthisdeviceisthegrandmaster,itwilltypicallyanother30
secondsbeforedevicesonthenetworkwillsynchronizeto
it.After30seconds,closethe“DeviceSettings”dialo
gand
re‐openittorefreshthePTPsettings.
Ifneeded,theusercanselectthe“Advanced(datasets)”
button.ThisgivestheuseraccesstothelowlevelPTPdata
setsdefinedinthePTP–IEEE1588standard. 
ItisbeyondthescopeofthisdocumenttodiscussthePTP
datasets.Pleaserefertoonlinesour
cesforhelpwiththese
values.Seethedetaileddescriptionofthetelnet/SSHPTP
interfacetogetadditionalinformationforsettingsinthe
datasets.
PTPCONFIGURATIONUSINGTELNET/SSH
TologinviatelnetorSSH,firstdeterminetheIPaddressofthedevice.Thiscanbeaccomplishedbyusing
WinDiscoveryormomentarilypressingtheResetbutton.WhentheresetbuttonispressedforamomenttheIPv4
andIPv6addresswillbeshownonthefrontpaneldisplay.NOTE:pressingtheRese
tbuttonformorethanone
secondwillcausethedevicetosetitselfbacktodefaults.
Thedefaulttelnetpasswordis“public”.Thereisnousername.
ThedefaultusernameforSSHis“public”andthepasswordis“publicpass”.ExampleSSHsettingsforTeratermare
showntotheleft.

Masterclock GMR5000 Specifications

General

Brand	Masterclock
Model	GMR5000
Category	Control Unit
Language	English