Symmetricom XL-GPS, User Manual

Page: 143 / 239

F110 – J1 Input (Time Code, TIET)
• Input Polarity : Positive only
Upon changing the settings, the last display prompt asks:
• Save Changes?: (Yes, No) Yes applies the changes. No cancels the changes.
For J1 specifications, See "Standard I/O" on page 5
• Time Code: The XL-GPS expects time code input that provides UTC in 24-hour
format. If the time code does not provide UTC in 24-hour format (e.g., it uses
standard, local, or GPS time, or is in 12-hour format), the XL-GPS’s internal clock will
be set to the wrong time when it uses the time code reference, and its time outputs
will be similarly affected.
• Time Code: IRIG and NASA 36 time code don’t contain “year” information. Enter the
current year using F3 before using IRIG as a primary or secondary reference source.
Failure to do so can cause the incorrect time information to be distributed. See
“F3 –
Time & Date” on page 52 .
• At the end of the year, the year increments by one (e.g., 2004 -> 2005), provided the
XL-GPS is operating during the transition. If it is not operating during the transition,
the time code reasserts the preceding year when used as a reference source.
• TIET: Put the F110 time code input on STANDBY first before configuring F110 for
TIET.
• TIET: Stray capacitance loading on the J1 input adversely impacts TIET
measurements.
Command Line
F110 can configure the J1 input port to IRIG-A, IRIG-B, NASA 36, TIET Time, TIET Event,
or IRIG 1344. Use F110 to enter or request the J1 Input Configuration.
To request the J1 Input Configuration, enter:
F110<CR>
The function responds with the ASCII character string:
F110<S><Code><S>-
<Source><S><Impedance><S><Type><S><Sign><S><Delay><S><Mode>
<S><Bypass><CR><LF>
Or
F110<S>TIET<S><Impedance><S><Sign><CR><LF>
(when TIET option is enabled and J1 is set to TIET)
Where the F110 entry and request formats are defined as:
098-00116-000 Rev. A ............................... Page 129 of 221