Specifications

Section-3 Operation
October 17, 2013
3‐32
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3.7.3 PFRUSetup
Figure 3-33 LPU PFRU Setup Screen
Table3‐23XmtrHome>ExciterHome>Setup>PFRU
Field Explanation
Frequency(MH
z) EnterlicensedfrequencyinMHzwithdecimals.
SFNO
ffset(Hz) FieldisavailableifSFNoptionisinstalledandfunctioning.
System
Re
ference
‐Int
ernalGPS(frominternalGPSreceiver)
‐Ext.1PPSref
erenceinput
‐Ext.10MH
zreferenceinput
‐Ma
nual(Controlof10MHzreferenceoscillatorfromtheDisciplineReferencewindow.)
The10MHzOC
XO(OvenControlledcrystal(X)Oscillator)isthereferencesourceforthe1stand2ndlocal
oscillators.Itcanbelocked,viaaPLL(PhaseLockedLoop),toanexternal1PPSsignalfromaGPSreceiver,to
anexternal10MHzreference,ortotheinternalGPSreceiver.
‐Aut
o1PPS.WhenselectedallowsseamlessswitchingbetweentheInternal1PPSandExternal1PPSandvice
versawithoutamute.Forthisfunctiontoworkcorrectlythefollowingconditionsmustbevalid:
‐Back
up1PPSmustbevalidandpresentfor60seconds.
‐Ava
lidsourceisindicatedwhenthe1PPSsignaliswithin+/‐5usoftheinternalsynthesized1PPSfor60
secondsconsecutive.
‐Cu
rrentselected1PPSsignalmustbemissingfor10consecutivesecondsbeforeaswitchtoavalidbackup
1PPSwilloccur.
‐On
ceswitchedtoabackup1PPSsourcetheexciterwillremainuntiltheprimary1PPSinputisre storedand
validfor60consecutiveseconds.
TheLPUprovidesanindicationviatheGUIfaultlogthataseamless1PPSswitchispossible.TheLPU
indicatesviathefaultlogthataseamlessswitchhasoccurred.
ReferenceLoss
Mut
e
‐Nomu
teonloss.
‐O
utputmutesimmediatelyuponref erenceloss.
‐O
utputmuteswhen20%ofGI(guardintervaltime)isexceeded
‐O
utputmutesafterenteredTimeOutvaluehasbeenexceeded
TimeOu
t(hours) ‐Enterintegervaluebetween1and100hours.
Discipline
Re
ference
OCXOman
ualsettingenteredasanumber,range1to100%.
Thispr
ovidesacontrolvoltageforthe10MHzOCXOref erenceoscillatorwhenManualsettingoftheSystem
Referenceisselected.Thisvoltagereplacesthephasedetectoroutputvoltagewhichcontrolsthe10MHz
OCXOreferenceoscillatorwhenanyoftheotherReferenceSourceisselected.TheOCXOfrequency
increasesastheco
ntrolnumberisincreased.
There
lationshipbetweenthenumberenteredandthe10MHzfrequencyisasfollows:
0
≈9.9999914MHz.(Thisisnominal.1%=lower.)
50%
≈10.0000008MHz.(mid,typical)
100%
≈10.0000107MHz.(high)