SERTEL T-GPS-300 User Manual - page 15
IRIG TIME CODE FORMAT
IRIG-B standard time format by telecommunication working group. Inter range
instrumentation group range commanders council describes IRIG-B it is available by writing
secretly range commanders council. White sand missile range New Mexico 880022. The
standard time formats of IRIG-B Code were designed for us in missile, satellite and space
research programmers. Use of these code facilities efficient interchange of test data. Those
formats are suitable for recording on magnetic tape oscillo graphics film and for real time
transmission in both automatic manual data reduction. IRIG-B from the SERTEL GPS /
MASTER CLOCK system is suitable for remote display driving magnetic tape recording and may
other use.
IRIG-B codes in the strip sense encode Universal Co-ordinate Time (UTC) in 24 Hours
format only, not local time. Nonetheless this instrument can encode UTC and IST time in 24
hours format.
The frame length of IRIG-B is 1 second long and contains 100 elements (pulse) each of
which starts every 10 millisecond (un modulated) and 1 millisecond (modulated). SERTEL
GPS/MASTER CLOCK provides output of IRIG-B in amplitude modulated signal (1 KHz) output at
rear panel of BNC Connectors. This will help us long distance communication.
The term IRIG signals is frequently used to refer to a whole group of serial time codes,
which use a continuous stream of binary data to transmit information on date and time. The
individual time code formats can be distinguished by the signal characteristics, e.g. modulated
versus unmodulated, which require different ways of signal transmission, by the data rate, and
by the kind of information included in the transmitted data.
Inter-range instrumentation group time codes, commonly known as IRIG time codes.
As per IRIG Standard 200-04,
IRIG time code
Code Bit rate
Bit time
Bits per frame
Frame time
Frame rate
B
100 Hz
10 ms
100
1000 ms
1 Hz
E
10 Hz
100 ms
100
10 s
0.1 Hz