Symmetricom Z3801A, User Manual

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Chapter 3 Using the Receiver Status Screen
Receiver Status Screen Data
3-16 User Guide
Time
When you first power up the unit the time and date that is stored in
the internal GPS Engine may not be the actual date. The actual time
and date will be valid after one satellite has been tracked by the
Receiver.
NOTE
There are two accurate ways to express time (GPS or UTC). GPS time
is offset from UTC time by the number of accumulated leap seconds
since midnight of January 6, 1980 UTC.
The Time area of the status screen provides three types of information:
Time , 1PPS CLK , and ANT DLY .
Time has four possible modes: GPS , UTC , LOCL GPS , and LOCAL .
GPS
indicates current time and date collected from a satellite in GPS
Time.
LOCL GPS indicates GPS Time, offset for the local time zone.
UTC indicates current time and date collected from a satellite in UTC
time.
LOCAL indicates current time and date collected from a satellite offset
from UTC for the local time zone.
1PPS CLK can indicate several possible advisory messages.
These messages are:
ANT DLY (antenna delay) displays the user-entered value that is used
to compensate for the propagation delay of the antenna cable.
Synchronized to
GPS Time
1 PPS locked to GPS, referenced to GPS Time.
Synchronized To
UTC
1 PPS locked to GPS, referenced to UTC.
Assessing
stability ...
applying hysteresis to locked 1 PPS signal.
Inaccurate,
not tracking
not tracking satellites.
Inaccurate,
inacc position
in survey mode, but has not yet calculated a position.
Absent or
freq incorrect
no 1 PPS signal; or the internal GPS Engine is idle.