The Gnss Reference - Spectracom SecureSync 1200 User Reference Manual

3.3 Managing References
2.
Confirm that the first reference in the Reference Priority table has "Local System" as the
Time input and "GNSS" as the 1PPS input.
3.
After a power cycle or reboot, as soon as GNSS is declared valid, the System Time will
automatically be used as-is, with no manual intervention required.
3.3.2

The GNSS Reference

With most applications, SecureSync will be setup such that it utilizes a GNSS signal as the
primary (if not the only) timing reference, because the time derived from a GNSS signal is
likely to be by far the most accurate time reference available. GNSS satellites (GNSS = Global
Navigation Satellite System e.g., GPS, GLONASS, Beidou, Galileo, QZSS) transmit a time sig
nal as part of their data stream, because a very precise time is required to accurately determ
ine your position on earth.
SecureSync's GNSS receiver uses the GNSS signal provided by the antenna.
The GNSS receiver analyzes the incoming GNSS data stream and supplies the GNSS time and
1PPS (Pulse-Per-Second) signal to SecureSync's timing system. The timing system uses the data to
control the System Time and discipline the oscillator.
While SecureSync's default GNSS receiver configuration will likely be adequate for most
installations, it is advisable that you familiarize yourself with the basic configuration features so
as to achieve the best possible results. This is particularly true if you have poor GNSS recep
tion.
To access the GNSS Receiver settings:
1.
Navigate to INTERFACES > REFERENCES: GNSS 0 .
2.
The GNSS 0 status window will open. To open the configuration window, click Edit in
the bottom-left corner.
OR:
1.
Navigate to INTERFACES > REFERENCES: GNSS Reference .
2.
Click on the INFO button, or the GEAR button to configure the GNSS settings, or review
GNSS reference status information.
Note that the configurable settings displayed in the configuration window are highly
dependent on superordinate settings, as well as receiver manufacturer and type in your
SecureSync unit:
166
In the Time field, select "Local System".
In the PPS field, select "GPS".
Check the Enabled checkbox.
Note: Typically, there will be only one GNSS reference, numbered "0".
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3 SecureSync User Reference Guide Rev. 23