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Group RDS : 4 version A
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PI code group type program type

 

The group 4A is used to transmit the hour and the date.

If this group is used, hours and date have to correspond exactly at the hour " Universal Time Coordinate " UTC + local offset. Otherwise the data must be positioned in 0.

When this group is used, it must be transmitted every minutes. The Clock time group is inserted so that the minute edge will occur within ± 0.1 seconds of the end of the Clock time group.

Hours and date are transmitted by using 34 bits, Assemble available data sets (part1,2 and 3) to form a block of 37 bits, 3 spare bits are used to complet the part 3.

UTC/Date Part 3
UTC/Date Part 2
UTC/Date Part 1
b4 b3 b2 b1 b0 b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0 b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
spare bits
  d16 d15 d14 d13 d12 d11 d10 d9 d8 d7 d6 d5 d4 d3 d2 d1 d0 h4 h3 h2 h1 h0 m5 m4 m3 m2 m1 m0 +/- o4 o3 o2 o1 o0

Modified Julian Date : The date of day is coded on 17 bits to form a number from 0 to 99999 allowing to determine the day, the month and the year, as well as the daytime of the week, the number of the week and the number of the year since 1900. (See secondary G of file rbds1998.pdf for details of conversion funtions).

Hour : The hours are coded by a binary value not signed on 5 bits and being able to vary from 0 to 23.

Minute : The minutes are coded by a binary value not signed on 6 bits and being able to vary from 0 to 59.

Local time offset : the offset is a multiple of half hour to vary of-12h in +12h.
The sign +/-is positioned in "0" for a positive offset and "1" for a negative offset..

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