Safran SecureSync 2400 - Page 618

Figure 5-69: IRIG E time code description
Additional information
The beginning of each 10 second time frame is identified by two consecutive 80
ms elements (P
0
and P
R
). The leading edge of the second 80 ms element (P
R
) is
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-
602 SecureSync 2400 User Manual
APPENDIX