Packet structure

+---------------------------+
|  RDS Information Word 1   |
|         (2 Octets)        |
+---------------------------+
|  RDS Information Word 2   |
|         (2 Octets)        |
+---------------------------+
|  RDS Information Word 3   |
|         (2 Octets)        |
+---------------------------+
|  RDS Information Word 4   |
|         (2 Octets)        |
+---------------------------+
|    RDS Offset Symbol 1    |
|         (1 Octet)         |
+---------------------------+
|    RDS Offset Symbol 2    |
|         (1 Octet)         |
+---------------------------+
|    RDS Offset Symbol 3    |
|         (1 Octet)         |
+---------------------------+
|    RDS Offset Symbol 4    |
|         (1 Octet)         |
+---------------------------+

Description

Each frame corresponds to a group in the RDS specification. The information words from the four blocks in the group appear first, in big-endian byte order, followed by an encoding of the offset words from the four blocks in the group.

The offset words contain a value that is one of:

• 0, for offset word A;
• 1, for offset word B;
• 2, for offset word C;
• 3, for offset word D;
• 4, for offset word C' (C-TAG);
• 5, for offset word E (MMBS);
• 255, if the offset word has an invalid value.