5: Function Reference
F8 – Continuous Time Once-per-Second
Note: This function is available through the command line interface only – it is not available
through the keypad.
F8 generates time-of-year information (e.g., 199:10:41:08) once-per-second over the XL-
GPS’s command line interface, which is available from the standard network port or the
serial port. The format and type of time can be modified using F2, F11, and F69.
If F8 is used following startup, while the XL-GPS is acquiring a reference source, F8’s
displays time-of-year information from the XL-GPS’s unsynchronized system clock. When
the system clock acquires a reference source and synchronizes with it, F8 displays the new
time-of-year information. The transition looks like this:
365:16:00:14?
365:16:00:15?
365:16:00:16
365:16:00:17
199:13:56:03
199:13:56:04
In the first two lines above, the unsynchronized time is followed by a “?” time quality
character. In this case, the “?” indicates that the XL-GPS is unlocked to a reference source.
As the XL-GPS locks to the reference source, the “?” disappears, and after a couple
seconds, the new synchronized time-of-year information appears.
If the reference source becomes unavailable again, F8 continues generating time-of-year
information based on the synchronized time, and the unlock “?” appears.
199:11:19:31
199:11:19:32
199:11:19:33?
199:11:19:34?
The format of time output can be changed using “F11 – Time Output Format” on page64.
The default output string format is:
<SOH>DDD:HH:MM:SSQ<CR><LF>
where:
<SOH>
= ASCII Start-of-Heading character (e.g., in decimal ASCII code: 001)
<CR>
= ASCII Carriage Return character; is output at the 1 PPS mark +/- 1 mS
<LF>
= ASCII Line Feed character
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