Spectracom VersaSync - 3.3.3 The GNSS Reference

The User/User reference is provided for the following use cases:
a.
No external references are available (yet), but you need a reference for testing or setup
purposes. This may be the case e.g., while waiting for a GNSS antenna to be installed.
b.
No external references are required e.g., if VersaSync is used solely to synchronize com-
puters on a network, with no need for traceable UTC-based timing.
c.
To utilize a backup reference as soon as possible after a power cycle or reboot of Ver-
saSync, while waiting for the primary reference (e.g., GNSS) to become valid. To this
end, in the Edit System Time window, the checkbox Synchronize to Battery Backed Time on
Startup must be checked, AND the User/User reference is assigned a reference priority
number other than "1". Note that a Time jump and/or 1PPS jump are likely to happen
once the primary reference becomes valid.
Combining a User Time reference with a non-User 1PPS reference or vice versa is not a typical
use case. Use the Local System reference instead, see "The "Local System" Reference" on
page133.
Built-in safety barrier
In order to "validate" (= green status lights) the User/User reference, the hand-set time must be
manually submitted every time after VersaSync reboots or resets, or after the Holdover period
has expired: In the Edit System Time window, the checkbox Manual Time Set must be checked.
The System Time displayed in the field below will become valid the moment the Submit button is
clicked.
See also below, "How long will the User/User reference be valid?": The notion of limiting the
validity of the User/User reference also serves as a safety feature.
How long will the User/User reference be valid?
Since the User/User reference does not qualify as a legitimate, traceable time, it becomes
invalid once VersaSync is reset, or power-cycles, or after the Holdover Time expires (whichever
occurs first). It then needs to be set manually and submitted again (Edit System Time > Manual
Time Set).
3.3 Managing References
CHAPTER 3 • VersaSync User Manual Rev. 6.0
135