48 XLi IEEE 1588 Clock
997-01510-03, Rev. C, 12/12/2006
SSSSSSSSSSSS SSSSSSSSSS SSSSSSS S SSS S SSSSS S
1
While Synchronizing to a Reference Source
Following startup, the user should avoid using F8 outputs until the XLi has acquired and locked to a
timing reference source such as GPS PRI (when F131 is set to PTP MASTER) or the IEEE 1588 card
(when F131 is set to PTP SLAVE PRIMARY).
F8’s output appears similar to the following example while the XLi locks and synchronizes to a reference:
001:00:13:45*
001:00:13:46?
...
001:00:14:05?
001:00:13:44
001:00:13:59
...
001:00:14:05
322:17:59:34
322:17:59:35
When the time quality characters clear, and the time-of-year synchronizes to the reference source time,
the F8 output string should be considered accurate and reliable.
After Loosing a Reference Source
If the system clock comes unlocked from the reference source (no reference sources available), F8
continues generating time-of-year information based on the synchronized time. Gradually, as the
estimated worst case time error (“F13 – Time Error”, page52) accumulates and exceeds each time
quality threshold (“F5 – Time-Quality Setup”, page43), F8 appends the appropriate time quality
character to the time-of-year string. This progression appears similar to the following example:
322:18:02:31
322:18:02:32.
322:18:02:33*
322:18:02:34*
Command Line
For example, to initiate Continuous Time once-per-second, enter:
F8<CR>
The XLi replies:
199:11:19:30<CR><LF>
199:11:19:31<CR><LF>
199:11:19:32<CR><LF>
To stop F8 Continuous Time Once-Per-Second, press Ctrl-C on your keyboard.