Radio Data System (RDS) through Technical Information For the MP3/CD Radios (US8, US9)
RADIO/AUDIO SYSTEM DESCRIPTION AND OPERATIONCONTENTS
- RPO Options
- Features
- Circuit Description
- Component Description
- Customer Tips
- On Board Diagnostics
- Theft Deterrent Feature
Radio Data System (RDS)
The CD/MP3 audio systems are equipped with technology known as the Radio Data System (RDS). The RDS is a system that sends data along with the audio of the FM station you are currently tuned to. The 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 the program to your receiver.
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 the FM Broadcaster does not implement RDS properly.
In some cases, a radio station broadcasting incorrect information may cause the RDS features of the radio to appear to work improperly.
Displaying RDS Information
The RDS feature is always ON. When tuned to a non-RDS station, the radio will display frequency information as you would normally expect. When tuned to an RDS station, the radio can operate as follows:
- The 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.
- Display the type of program.
- Display general information such as artist and song title, call in phone numbers, etc.
Viewing and Selecting RDS Information for Display
Press the RCL button once for less than 2 seconds when the radio displays the program service (PS) name and the frequency of the station will be displayed. Press the button again, and the program type (P-Type) will be displayed. Pressed again, and the program type (PTY) name will be displayed, if the broadcaster is broadcasting one. The PTY name is an eight-character name that the broadcaster may use to further identify the type of programming currently being broadcast. Should you decide that Frequency, P-Type or PTY name is more desirable to display when tuned to an RDS station than the PS name, press the RCL button until the desired information is displayed, then press and hold for more than 2 seconds. A beep should be heard and the radio will now display the selected information whenever tuned to an RDS broadcaster. The radio will display frequency for all non-RDS broadcast stations.
Using RDS Program Types to Tune Radio
Listed are several ways on how to tune your radio using RDS program types. The radio will now be configured to tune based on RDS data rather than frequency
Finding a RDS Station By Specific Program Type
1. Press the PROG TYPE or P-TYPE button, the radio will display the current P-Type to search for.
2. Press the CAT rocker button until the desired program type is shown in the display.
3. Press the SEEK button and the radio will now seek the first RDS Broadcaster of the selected P-Type.
If the radio cannot find the desired P-Type, the radio displays NOT FOUND and will return to the last station you were listening to.
Using the INFO Feature
When the INFO icon appears in the radio display, a new text message is available for viewing. These text messages are from the RDS broadcaster to the listening public and may be general information such as artist and song title, call in phone numbers, etc.
How to View the INFO Message
- To view the message when the INFO icon appears, press the INFO button to display the text message. If you do not press the INFO button again, the text message will automatically be displayed 8 characters at a time, 3 seconds between updates.
- To view the text message faster, press the INFO button for less than 1 second to scroll through the message at your own speed.
- The INFO icon disappears as soon as you press the INFO button. The INFO icon will appear when a new different message is received.
- To view the most recent received message, press the INFO icon at any time, even if the icon does not appear in the display.
Controlling the Radio
The user can activate RDS to control the radio by using the data received to do the following:
- Interrupt the playback of your CD for traffic or emergency bulletins.
- Search for stations by type of program.
- Set your clock to the time that the RDS broadcast station broadcasts.
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 TA icon in the radio display. Not all FM broadcasters will use this RDS feature. 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 "TA" icon will appear on the radio display, as will brackets around the [TA] icon. If the radio cannot find an RDS traffic station after searching through the entire FM band, the radio will display NO TRAFFIC.
Traffic Interrupt Feature
Whenever the TA icon is displayed, the current FM station may also broadcast traffic announcements. Traffic announcements are reports of the current traffic conditions in the listening area of the tuned FM broadcasters.
Your radio can interrupt the playback of a compact disc by use of the traffic interrupt feature. The traffic interrupt feature is enabled when the TRAF icon is displayed.
If the broadcaster sends out a traffic announcement while you are listening to FM or in the playback mode, TRAFFIC will be displayed on the radio and the audio from the broadcaster will be heard. At the conclusion of the traffic announcement, the radio will return to the previous playback mode.
During the time the radio displays TRAFFIC, you can adjust the volume of the traffic announcement. This will be the volume at which all future traffic announcements will be heard until the volume during another traffic announcement is adjusted.
You can also interrupt a traffic announcement interrupt by pressing the TRAF button.
During a national or local emergency, a special program type interrupt message ALERT! is displayed. This special announcement will cancel all other RDS features that are in progress, such as a traffic announcement.
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 RCL and RDS buttons together for two or more seconds to update the time.
- The display will show SET RDS TIME after receiving the broadcasted time data.
- If the broadcaster is not broadcasting the time data, the radio will display NO RDS TIME SET and the time remains unchanged.
AM/FM RECEPTION
Radio Signal
The radio signal is sent from a broadcast station and is then received by an antenna. The strength of the signal received depends on the following:
- The power output, or wattage, of the broadcasting station
- The location of the vehicle, or receiver, relative to the broadcast tower.
- Obstacles between the tower and the receiver
- Atmospheric conditions
- Which band, AM or FM, the station is broadcasting
- Type of antenna and the ground plane
AM Reception
The AM band has a lower frequency range than the FM band. These longer wavelengths:
- Bend around obstacles
- Follow the curvature of the earth
- May reflect, or skip, off of the ionosphere
The AM frequencies have longer range due to the ground wave. The ground wave follows the curvature of the earth and is affected by its conductivity. Greater conductivity equates to less signal loss, thus transmission over water is better than over land. The AM band has a range of 80-320 km (50-200 mi).
FM Reception
The shorter wavelengths of the higher frequency FM band:
- Reflect off obstacles
- Are absorbed by the ground
- Penetrate the ionosphere
Broadcasts in the FM band are limited to "line of sight" reception which is typically 40 km (25 mi). Even when out of a direct line of sight, the signal may be reflected into areas that would be in a "shadow" otherwise. Factors which affect the line of sight include:
- Height of the broadcast antenna
- Height of the receiving antenna
- Terrain and buildings in the broadcast path
XM Reception
XM satellite radio provides digital radio reception. The XM signal is broadcast from two satellites and, where necessary, terrestrial repeaters. The high power satellites allow the antenna to receive the XM signal even when foliage and other partial obstructions block the antennas view of the satellite. Terrestrial repeaters are used in dense urban areas. These repeaters will receive the satellite signal and re-broadcast them at much higher power levels in order to ensure reception in areas with densely packed tall buildings.
XM Satellite Radio
XM is a national satellite radio service that offers up to 100 coast to coast channels including music, news, sports, talk and children's programming. XM provides digital quality audio and text information, including song title and artist name. A service fee is required in order to receive the XM service. For more information, contact XM at www.xmradio.com or call 1-800-852-9696.
Digital Radio Receiver
The radio controls communicate with the digital radio receiver via the class 2 communication circuit. The digital radio receiver sends remote radio audio signals to the radio.
Viewing Messages
Press the DISP or RCL button while in XM mode to view various pieces of information related to the current song or channel. By pressing and releasing the DISP or RCL button, you may view four different categories of information: Artist Name/Feature, Song/Program Title, Channel Category, and other Additional Information that may be broadcast on that channel. Additional Information messages may not always be available. If an Additional Information message is being broadcast on the tuned channel, the INFO icon will appear on the display. Each of the four information types may have multiple pages of text. To reach a category, press and release the DISP or RCL button consecutively until the desired type is displayed. If there are multiple pages of text for the selected information type, the radio will automatically display all the pages for that type at a rate of approximately one page every three seconds before timing out and returning to the default display. You may override this feature by pressing the DISP or RCL button to review all of the pages at your own pace.
TECHNICAL INFORMATION FOR THE MP3/CD RADIOS (US8, US9)
The US8 and US9 radios will play both standard audio CDs and CD-Rs or CD-RWs. The CD-R/RWs may contain either standard audio (*.cda) or compressed audio (*.mp3).
Customers who record their own music CD-R/RWs should be aware of the following:
- The files can be recorded on a CD-R/RW disc with a maximum capacity of 700 MB.
- The radio will play only compressed audio files recorded in the *.mp3 format. It also supports playlists that can be made and saved with popular MP3 software (in the *.m3u format). A playlist name must be no more than 32 characters in length. If the name of a playlist is longer than 32 characters, the radio will ignore the playlist.
- The radio will only play audio from a CD-R/RW, it cannot record audio.
- The radio will play a mixed mode CD-R/RW (one recorded with both *.cda and *.mp3 files). If a mixed mode CD is inserted in the radio,, the radio will assign the standard CD audio to a directory which is listed as ROM audio directory.
- The radio supports multi-session discs, but only the files from the last session will be played.
- There are a total of 20 directories (folders) allowed on a disc. The file structure can be 0-4 directories deep (a folder within a folder, within a folder, etc). Anything more than 20 directories will be ignored. Each directory may have up to 99 files contained within it. Files not having the *.mp3 extension will not be played, but still count toward the maximum. Anything more than the first 99 files within a directory will be ignored. A single disc may have up to 254 files and directories. Anything beyond the 254 limit will be ignored.
- MP3 files must be written to a CD-R/RW in one of the following industry-standard formats:
- ISO 9660 Level 1
- ISO 9660 Level 2
- Joliet
- Romeo
- ID3 tag information is displayed by the radio, if available. The ID3 tag information can either be version 1 or 2. The radio will display the filename, song name, artist name, album name, directory name, and playlist name..
If the customer does not follow these guidelines when recording a CD-R/RW, the disc may not play in the US8 or US9 radio.