E: Time Code Formats
element and a position identifier or reference marker is 0.8 of the duration of an element. A
reference marker locates the beginning of each frame and a position identifier marks the end
of every ten elements. IRIG-B has ten position identifiers per frame.
The elements prior to position identifier P5 comprise the time of year segment. The first ten
elements encode the seconds, the second ten elements encode the minutes and so on
through days. Each element is a digit in a binary number with a place value sequence 1 2 4 8.
IRIG-B Time Quality Flags
Five flags are encoded in the control function segment of the IRIG-B code. The first flag
encoded at element P5+40ms is the LOCK indicator. It is a binary 1 when the XL-GPS is not
locked to a reference. The second flag encoded at element P5+60ms is a binary 1 when the
worst case time error exceeds threshold 1 (refer to "Function 5 -- Time Quality
Enable/Setup"). Element P5+70ms is a binary 1 when the worst case time error exceeds
threshold 2. Element P5+80ms encodes a binary 1 when the error exceeds threshold 3 and
P5+90ms when the error exceeds threshold 4.
Output
The XL-GPS provides the following IRIG time code outputs (refer to IRIG Standard 200-95):
IRIG-B: B120 1 kHz sine wave amplitude modulated with BCD, CF, SBS
B000 DC level shift, width coded with BCD, CF, SBS
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Summary of Contents for XL-GPS
Page 1: ...XL GPS Time Frequency Receiver User Guide CD Part Number 098 00116 000 Rev A 5 May 2010 ...
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Page 220: ...I Certificate of Volatility See the following document 098 00116 000 Rev A Page 206 of 221 ...
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Page 225: ...J Declaration of Conformity See the following document 098 00116 000 Rev A Page 208 of 221 ...