Radio Data System (RDS)

WARNING: This page is about a different car, the 2007 Isuzu i-370, 2007 Isuzu i-290, 2007 GMC Canyon, and 2007 Chevrolet Colorado. However, it is still accessible from the selected car via links, so may be relevant.

All uplevel audio systems are equipped with technology known as the radio data system (RDS). RDS is a system that sends data along with the audio of the FM station you are currently tuned to. RDS is a standard that defines how a FM broadcast station may send digital data along with the audio program. Think of it as a one way wireless modem, allowing the broadcaster to send information about his program to your receiver.

RDS data is carried in what is known as a "sub-carrier". A sub-carrier is a frequency that the FM broadcaster is authorized to use to send data or other audio programs that are not audible in the main audio program. RDS information can be used to display program information and to control the radio.

To receive the RDS signal, all that is needed is an FM receiver with a RDS circuit. A special integrated circuit capable of dealing with the RDS signal is in the RDS circuit and passes it along to the receiver's microprocessor where it is decoded and acted upon.

RDS Basic Information

RDS basic information:

RDS functions are provided in the FM broadcast band only.
RDS functions will only work with FM broadcast stations that are broadcasting RDS data.
Not all FM Broadcast stations broadcast RDS data or offer all of the RDS services.
RDS functions may not work properly when reception is weak, reception is of poor quality, or RDS is not implemented properly by the FM Broadcaster.

In some cases, a radio station broadcasting incorrect information may cause the RDS features of the radio to appear to work improperly.

Broadcast RDS information can be used in a variety of ways by the receiver and listener, but basically falls into 2 categories: Display and Control.

Displaying Program Information

RDS displays textual information such as:

The name of the station
The type of program
General information such as artist and song title, call in phone numbers, etc.

RDS is always on. When tuned to a non-RDS station, your radio will display frequency information as you would normally expect. When tuned to a RDS station, your radio will change from displaying the frequency of the FM station to displaying the call letters of the station or display the nickname of the station. This feature is known as the Program Service Name.

Controlling the Radio

RDS can control the radio when data the receiver can use responds to timely information performing the following:

Interrupt the playback of your cassette or CD for traffic or emergency bulletins.
Search for stations by type of program.
Automatically follow networked programming from transmitter to transmitter as you travel from one listening area to another.
Set your clock to the time that the RDS Broadcast station broadcasts.

Viewing and Selecting RDS Information for Display

Press the TUNE knob once for less then 2 seconds when the radio displays the program service name and the frequency of the station will be displayed. Press the knob again, and the program type (PTY) will be displayed. Pressed again, and the program name will be displayed (if the broadcaster is broadcasting one). The program name is an eight-character name that the broadcaster may use to further identify the type of programming currently being broadcast.

Using the RDS Traffic Feature

Some RDS broadcasters may carry traffic information programming to inform you of current traffic conditions in your listening area and is indicated by the icon in the radio display. RDS enables the broadcaster to get this information to you even when you are listening to a tape or compact disc. This feature can be enabled or disabled by the listener. Press the TRAF button to find a station that claims to carry traffic information. You may do this even when playing a cassette tape or compact disc. This action will operate in the background without interrupting the current playback. If the radio is not currently tuned to an RDS traffic station, the radio will immediately SEEK an RDS traffic station. If the radio finds an RDS traffic station, the TRAF icon will appear in the radio display as will brackets around the (TRAF) icon. If the radio cannot find an RDS traffic station after searching through the entire FM band, the radio will display NO TRAFFIC.

Alternate Frequency (AF) Switching

RDS permits broadcaster's to send information to the radio that allows the radio to automatically switch frequency to the best quality station in that broadcaster network.

Since the radio is displaying the broadcaster call letters or nickname, the listener will not see the frequency during an AF switch unless you have changed the default display to be frequency instead of Program Service name.

To enable or disable AF switching perform the following:

Press and hold the AM/FM button for 2 seconds or more.
The radio will display AF ON or AF OFF depending on the current condition of AF and a confirmation beep will be heard.

When AF is enabled and you recall a RDS station stored on preset, the radio determines if the station stored is of acceptable quality. If not, the radio checks all available AF's for your station. If the radio fails to locate your program, AF SEARCH will be displayed as the radio scans across the band looking for your program or an affiliated network. If the radio cannot find the original station or an acceptable alternate frequency NOT FOUND will be displayed and the radio returns to the original frequency for the preset.

RDS Clock Time

Broadcasters can choose to send clock time information in the RDS data. This information can be used to update the clock time on the radio. RDS clock time is broadcasted once a minute. To set the clock using RDS clock data perform the following:

Press and hold the HR and MIN buttons together for 2 or more seconds to update the time.
The display will show UPDATED after receiving the broadcasted time data.
If the broadcaster is not broadcasting the time data, the radio will display NO UPDATE and the time remains unchanged.