Doctor_Technical said:Depends on what you mean by scroll. RDS works by multiplexing many different types of data (PS, RT, CT, etc.) into one ~1200 bps serial stream. The order and rate-of-repetition of each type of data depends both on RDS standards and the individual station's choice to prioritize one type of data over the other.
This is interesting information. It explains why the RT field on several radio stations will lag behind the PS. Magic 96 comes to mind. The song info would be on both the RT and PS, but the RT might not update until halfway through the next song.
Some stations I've observed seem to have a problem keeping everything running smoothly. Could you shed some light on these situations? The first and most annoying is stations where the RDS seems "weak" even in strong signal areas. The Citadel stations in B'ham come to mind: WZRR, WYSF both have this issue. They use regular, static PS - nothing scrolling. But the RDS indicator on every radio I've had would pop on and off randomly, even right near the transmitter. It usually took anywhere from 10-60 seconds for the PS to display.
Another market of bad RDS that comes to mind is Charlotte. Haven't been there in a while so things may have changed but I remember many stations running RDS but with NO PS or RT, just PTY.
Right now here in Mississippi the Supertalk network seems to be having trouble with their RDS as well. The indicator lights sporadically. It appears they turned off the stereo on these stations, at least around me.