Safran VersaSync - Page 397

the "on time" reference point for the succeeding time code. 1PPS position iden-
tifiers P
0
, P
1
… P
9
(80ms duration) occur 0.1s before 1PPS "on time" and refer to
the leading edge of the succeeding element.
The time code word and the control functions presented during the time frame
are pulse-width coded. The binary "zero" and index markers have a duration of
20ms, and the binary "one" has a duration of 50ms. The leading edge is the 10
pps "on time" reference point for all elements.
The binary coded decimal (BCD) time-of-year code word consists of 26digits
beginning at index count 6. The binary coded subword elements occur between
position identifiers P
0
and P
5
(3 for seconds; 7 for minutes; 6 for hours; 10 for
days) until the code word is complete. An index marker occurs between the
decimal digits in each subword to provide separation for visual resolution. The
least significant digit occurs first. The BCD code recycles yearly.
Forty-five control functions occur between position identifiers P
5
and P
0
. Any
control function element for combination of control function elements can be pro-
grammed to read a binary "one" during any specified number of time frames.
Each control element is identified on the Control Function Field Table.
Table 5-34:
IRIG E control function field
BIT No. CF ELEMENT No. FUNCTION
50 1 SPACE
51 2 SPACE
52 3 SPACE
53 4 SPACE
54 5 SPACE
55 6 TIME SYNC_STATUS
56 7 SPACE
57 8 SPACE
58 9 SPACE
59 PID P6 POSITION IDENTIFIER
60 10 YEAR UNITS Y1
61 11 YEAR UNITS Y2
62 12 YEAR UNITS Y4
VersaSync User Manual 383
APPENDIX