Spectracom VelaSync 1225, User Manual

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1.
Navigate to MANAGEMENT > OTHER: Disciplining .
2.
Click the GEAR icon at the top of the Status panel. The Oscillators Settings win-
dow will display:
3.
Populate the fields:
Maximum TFOM for Sync : When TFOM (Time Figure of Merit, see also
"Time Figure of Merit (TFOM)" on the facing page ) is greater than Max
TFOM, disciplining will still be attempted against the selected reference to
improve the TFOM. If the condition persists, the system will transition to
holdover, and eventually out of sync. When disciplining is performed such
that TFOM is no longer greater than max TFOM, the system will transition
back into sync.
Holdover Timeout(s) : The default is 7200 s (= 2 hours).
For more information on holdover timeouts, see "Typical Holdover lengths
in seconds" on page 151 . For additional information on holdover, see "What
is "Holdover Timeout"?" on page 149 .
Phase Error Limit : [Default=0 (disables this feature)]. Setting a Limit
(valid for +/-) for the Phase Error between an external 1PPS reference and
the System 1PPS will cause the disciplining tracking to restart auto-
matically (after a few minutes delay) if that limit is exceeded. This will help
to quickly re-align the System 1PPS with a reference.
When using a Host Reference as a primary or backup reference, for
improved performance it is recommended to set the phase error limit for
NTP to a suggested value of 100000 ns (= 1 µ second). Adjust this value as
needed, based on your accuracy requirements.
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CHAPTER
3
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VelaSync User's Manual Rev. 3
3.4 Managing the Oscillator