APPENDIX
SecureSync can provide various IRIG code in amplitude modulated (AM) or pulse
width coded (TTL) formats, depending on your unit configuration and additional
options. A signature control feature may be enabled for any IRIG output. Sig-
nature control removes the modulation code when a Time Sync Alarm is asser-
ted.
5.5.3
IRIG B Output
The IRIG B Time Code description follows.
Figure 5-67:
IRIG B time code description
The IRIG B code contains the Binary Coded Decimal (BCD) time of year, Control
Function (CF) field and the Straight Binary Seconds time of day. The following fig-
ure illustrates the IRIG B data structure. The BCD time of year provides the day of
the year, 1-366, and the time of day including seconds. The hour of the day is
expressed in 24 hour format. The SBS time is the number of seconds elapsed
since midnight. The Control Function field contains year information and a time
synchronization status bit.
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