Holdover Mode - Safran SecureSync 2400 User Manual

3.4 Holdover Mode
3. Under
3.4

Holdover Mode

When input references have been supplying input to SecureSync and input from
all the references has been lost, SecureSync will not immediately declare loss of
time synchronization, but first will go into Holdover mode. While the unit is in Hol-
dover mode, the time outputs are derived from the internal 10 MHz oscillator
incrementing the System Time, but the oscillator is not disciplined/steered by the
external reference e.g., GNSS.
Because of the stability of the internal oscillator, accurate time can still be
derived even after all the primary references are no longer valid or present. The
246
Identified Satellite Signal Strengths
the bars: The letter in the tooltip window displayed for each signal bar indic-
ates which constellation the satellite belongs to:
Letter sym- GNSS Con-
bol stellation
G GPS
R GLONASS
E Galileo
J QZSS
C BeiDou
I IRNSS
The number next to the letter indicates the satellite number. The number
below indicates the signal strength (C/N
hover with your cursor over
).
o
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3 SecureSync 2400 User Manual Rev. 5.2