Radio Data System, or RDS, is a standard for sending small amounts of digital information over conventional FM radio broadcasts. RDS also standardizes a number of types of information transmitted using the system, including time, station identification and similar information. RDS is widely used in Europe. While an almost-identical system is available in North America, known as RBDS, it is not widely used there.

The following information fields are normally contained in the RDS data - See also (PDF) RDS Features Serving as Tuning Aids:

  • AF, Alternate frequencies. This allows a reciever to re-tune to a different frequency providing the same station when the first signal becomes too weak (e.g. when moving out of range)
  • CT, Clock Time. Can synchronise a clock in the receiver or the main clock in a car.
  • EON, Enhanched Other Networks. Allows the reciever to monitor other stations for Traffic broadcasts.
  • PS, Program Service.
  • PTY, Program Type. A number of pre-defined music types (e.g. Classics, Pop, Middle of the Road Music) allowing a user to find a similar station.
  • REG, Regionale links
  • RT, Radio Text, Radiotekst.
  • TA, TP, Travel announcements. The reciever can often be set to pay special attention to this flag and e.g stop the tape or retune to recieve a Traffic bulletin.
  • TMC, Traffic Message Channel. Demands a RDS-TMC decoder.

See also: DirectBand

External links:

Technical RDS-TMC (External addresses)

Technical (External addresses)