RDS system enables digital information broadcast within FM radio program not influencing the audio signal quality .
IMTEL Microwaves produces RDS coder which is a standalone device designed for implementation at emitting site. Input MPX signal is transformed into output MPX signal with RDS signal. Dynamic changing of RDS messages requires additional PC computer and a program that sends the data to RDS coder through a serial port, and which is offered with the RDS coder.

Main characteristics of the RDS coder are:

• digitally generated RDS signal,
  
• the device fully meets international standard CENELEC EN 50067,
  
• new messages reception through RS232 port according to EBU protocol,
  
• monitoring  of the generated messages content through LCD display,
  
• RDS phase adjustment through keyboard,
  
• PC program "Network Center" that sends through serial port RDS messages according to EBU protocol.
  

Operation description:

1) The part that generates RDS messages compirses microcontroller, SRAM which stores data to be emitted, and which comprises Real Time Clock. The data stored in RAM can be arranged through RS232 port, and read at LCD display.

2) The part that performs 57 kHz subcarrier modulation - the signal is digitally generated and then D / A converted and added to MPX signal.

3) The third part consists of 19 kHz filter that filters pilot, and analogue PLL for subcarrier and pilot synchronizatoin. The subcarrier is synchronized to the pilot's third harmonic.

TECHNICAL CHARACTERISTICS