TRAK MODEL 9100 MODULAR FREQUENCY/TIME SYSTEM
C-2
TM4400013
REV.
D
APPENDIX C
IRIG B CODE FORMAT
The IRIG B time code has a one-second time frame and
contains BCD time information representing seconds,
minutes, hours, days and straight-binary-time-of-day
(SBTOD) in seconds. Provisions are made in the format for
control functions. An 8-millisecond frame reference marker
appears during the first 10 ms of each frame, and 8-
millisecond position identifiers appear during the 90
th
millisecond of each 100 millisecond period. The BCD time
data appear in the
First five 100 millisecond time periods of each one-
second frame, control functions (when used) appear in
the next three 100 millisecond time periods, and the
SBTOD data appear in the last two 100 ms time
periods. Binary ZEROs and fill bits are 2 ms long, and
Binary ONEs are 5 ms long. Modifications to the code
include deletion of the days data, deletion of the
SBTOD data, and deletion of both of these data
groups
