SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS

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”, page 52) accumulates and exceeds each time quality threshold (“F5 Time-Quality Setup”, page 43), 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.

48

XLi IEEE 1588 Clock

997-01510-03, Rev. C, 12/12/2006

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Image 56
Symmetricom XLi IEEE 1588 While Synchronizing to a Reference Source, After Loosing a Reference Source, XLi replies, F8CR