Note: The TAI timescale also does not observe leap seconds. The
TAI timescale is fixed to always be 19 seconds ahead of GPS time. As
of 5-March-2024 TAI time is 37 seconds ahead of UTC.
VersaSync's System timescale is configured via the MANAGEMENT > OTHER:
Time Management screen, see "System Time" on page158.
Input timescales
Some of the inputs may not necessarily provide time to VersaSync in the same
timescale selected in the System Time’s timescale field. These inputs have
internal conversions that allow the timescale for the inputs to also be inde-
pendently defined, so that they don’t have to be provided in the same timescale.
For example, the System timescale can be configured as “UTC”, but the IRIG
input data stream can provide VersaSync with “local” time, with no time jumps
occurring when the reference is selected.
If an output reference is using the GPS or TAI timescale, and the System Time is
set to “UTC”, then the GPS Offset box in the Edit GPS Offset window must be
populated with the proper timescale offset value in order for the time on the out-
put reference to be correct. Some references (like GNSS) provide the timescale
offset to the system. In the event that the input reference being used does not
provide this information, it must be set in through the Offsets panel of the Time
Management page.
Since the GPS and TAI offsets have a fixed relationship, only the GPS offset can
be set. If only the TAI offset is known, subtract 19 from it to get the GPS offset.
Note: If the System Time is set to the UTC timescale, and all output
references either use the UTC or “local” timescale, then it is not
necessary to set the GPS and TAI timescale Offsets.
Caution: It is imperative to configure any input reference’s times-
cales appropriately. Otherwise, a System Time error may occur!
Output timescales
Some of the available VersaSync outputs (such as the ASCII data module’s out-
puts, etc.) won’t necessarily output in the same timescale selected in the System
Time’s timescale field. These outputs have internal conversions that allow the
160
CHAPTER 3 • VersaSync User Manual Rev. 12
3.2 System Time
To Next Page
Loading...
