Orolia Spectracom VelaSync 1232, Руководство пользователя

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VelaSync’s internal oscillator is normally disciplined to an input reference (such as GNSS,
IRIG input, 1PPS input, etc.) in order to provide the highest degree of oscillator accuracy
and to account for oscillator drift. While disciplining (with a 1PPS input reference input
present and valid), the oscillator’s output frequency is monitored and based on the meas-
ured frequency, the oscillator is steered to maintain a very accurate 10 MHz output. If no
valid 1PPS input references are present (or input references are present but not con-
sidered valid), the oscillator will be in Freerun mode instead.
If no external input reference such as GNSS, IRIG, etc. is available (or is temporarily lost),
VelaSync may become an NTP Stratum 2 or higher reference. If so configured, VelaSync
can use a reference such as an NTP daemon, referred to as a
Host Reference . If the Host
Reference becomes active, it will automatically take over the disciplining of the oscillator.
This built-in functionality is referred to as
Host Disciplining .
Figure 3-2:
Host disciplining
Note: Host disciplining is NOT supported by VelaSync units that are
equipped with a Rubidium oscillator.
The Oscillators Settings page provides the user with some control of the disciplining pro-
cess. This page is also used to configure the length of time VelaSync is allowed to remain in
the Holdover mode when all references are lost.
3.4.1 Configuring the Oscillator
VelaSync is equipped with an internal oscillator. To configure the oscillator settings:
3.4 Managing the Oscillator
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VelaSync 1232 User Manual Rev. 4 153