Safran CORTEX Series - Absolute Time Reference

HIGH DATA RATE RECEIVER
HDR-4G+ USER’S MANUAL
Ref. DTU 100782
Is.Rev 3.5
Date: June 1, 2021
© Safran Data Systems – IMP000074 e14r1
This document is the property of Safran Data Systems.
It cannot be duplicated or distributed without expressed written consent.
Page 242
Absolute Time Reference 4.5.3.3.3
The IRIG-B and NASA-36 time codes are serial time format with the time-of-year coded in Binary
Coded Decimal (BCD) notation as days, hours, minutes and seconds. Years are not coded and the day
counter is reset every January 1
st
, 00 h, 00 mn, 00 s. Time parameters can be programmed so that the
day counter will not be restarted every year.
Example:
 The absolute time reference is January 1
st
, 1998 at 0 AM.
 The CORTEX is started in the course of 1998 with Current Offset = 0.
The procedure is as follows:
1. Enter: Date of Next Offset 1 = Date of Next Offset 2 = 0
Next Offset 1 = 31 536 000 (year 1998 = 365 days = 31 536 000 seconds)
2. On January 1
st
, 1999 at 0 AM, check that the Current Offset is set to 31 536 000 and that the
time-tags are updated accordingly (365 days are automatically added to the time-tags). The day
counter is equal to 366.
3. In the course of 1999, enter Next Offset 1 = 63 072 000 (year 1999 = 365 days = 31 536 000
seconds).
4. On January 1
st
, 2000 at 0 AM, check that the Current Offset is set to 63 072 000 and that the
time-tags are updated accordingly. The day counter is now equal to 731.
5. Each following year, increment parameter Next Offset 1 by the number of seconds of the
current year.