Symmetricom XL-GPS - Manual (Page 47)

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F3 – Time & Date
When an optional oscillator is used because a GPS signal is unavailable, use function F3 to manually
set the XL-GPS system clock’s time and date. When the XL-GPS is using GPS as timing reference,
setting F3 manually is unnecessary. At startup, the XL-GPS synchronizes its time and date to GPS.
F3 prompts the user for the Time Mode, the Date in mm/dd/yyyy format, and the Time in hh:mm:ss
format. The hours in hh:mm:ss should be given using 24-hour notation (e.g., 6 pm = 18:00).
TIME MODE selects which type of time (Local/Standard/GPS/UTC) is being entered by the user. The
XL-GPS, translates the user entry into its equivalents in other types of time. For example, entering
LOCAL - 07/14/2002 - 15:47:10 in F3 shows up on the front keypad display as UTC 198:10:47:10, with
F1 set to –8:00. TIME MODE in F3 defines only the entry of time in F3; it does not control the type of
time displayed or output by the XL-GPS. F3’s Time Mode should not be confused with F69 (see
“F69 –
Time Mode” on page 61 ). F69 controls the type of time displayed/output on the front panel display, F8 –
Continuous Time Once-per-Second , F9 – Time On Request , and F90 – Code Output Configuration .
Notes:
• Don’t manually set the time using F3 settings while the XL-GPS is locked to a reference source
and distributing time information. Doing so allows the XL-GPS to distribute the potentially incorrect
time set by F3 for up to 8 seconds until the XL-GPS re-synchronizes to the reference source’s
time. The XL-GPS will make this switch to and from F3’s time without generating an alarm. In NTP,
for example, this means that incorrect time information could be distributed in NTP packets that
are marked as having the valid time.
Command Line
To display the time and date, send:
F3<CR>
XL-GPS responds:
F3<S><MM>/<DD>/<YYYY><SEP><hh>:<mm>:<ss><CR><LF>
where:
F3
= ASCII string for function F3.
<S>
= ASCII space character (one or more).
<TIME MODE>
= the time mode the entered time refers to; LOCAL/STANDARD/GPS/UTC
<SEP>
= one or more separator characters: either space, comma or tab
<MM>
= two-digit month
<DD>
= two-digit day of month
<YYYY>
= four-digit year
/
= ASCII character for slash delimiter