Spectracom VelaSync 1225, Руководство пользователя

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Note: You will need to repeat this procedure each time VelaSync is
power-cycled (with no other references available), unless you enabled
the feature Synchronize to Battery Backed Time on Startup.
Example 5—Time at power-up ("Local System Time") to be considered
"Valid". GNSS input to serve as 1PPS reference
The objective of this use case is to allow VelaSync to use itself as a valid reference. This
is referred to as “Local System” time.
In order for this to happen, VelaSync requires an external Time, or 1PPS reference. In
other words, "Local System" cannot be both Time,
and 1PPS. This makes "Local Sys-
tem" a legitimate, traceable reference.
Therefore the "Local System" does not have to be manually set ("validated") by the
User after VelaSync was power cycled (as would be the case with a “User/User” ref-
erence).
Since “Local System” cannot be both Time , and 1PPS input together, in this example
the GNSS input will be set as the 1PPS reference (other use cases may require using dif-
ferent references, e.g. IRIG.)
As there is no default entry for “Local System” and “GPS”, a new entry needs to be
added to the
Reference Priorities table in order to use this combination of references.
Step-by-step procedure:
1.
Add a reference to the Reference Priority by clicking the PLUS icon. Use the fol-
lowing settings, then click
Submit :
In the Priority Level text box, enter 1 . This will give this reference the
highest priority.
In the Time field, select “Local System”.
In the PPS field, select “GPS”.
Check the Enabled checkbox.
2.
Confirm that the first reference in the Reference Priority table has “Local Sys-
tem” 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 Managing References
CHAPTER
3
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