RDS

"RDS" stands for "Radio Data System" and it allows FM broadcasters to send far more than just an analogue audio signal out over the air waves. Using a 57 kHz "subcarrier," stations can transmit digital RDS data for reception by RDS-equipped FM tuners. This technology opens up a whole new range of features help to the listener with RDS reception capability. Typical information can you expect depends on what the broadcaster transmits and what your device can pick up. There are two categories, Static and Dynamic.

A full description of the system is here.

RDS "Static" services include:

Program Service Name (PS): This is a displays a name instead of frequency. Program Type Code (PTY): This identifies a particular type of broadcast (Rock, Jazz, Sports, Talk, News, Classical, etc.) So far, 24 categories have been defined and assigned in the RDS system. Program Identification Codes (PI): Is a four-digit hexadecimal code. It is allocated on a country basis and usually made up of a Country Identifier followed by 3 ID unique characters. This is one of the rarely-seen "hidden" RDS features . Alternate Frequency (AF): If PI is one of RDS’ "back office" functions, AF is what you’ll see in action all the time. Alternate Frequency Switching (AF) automatically returns your FM tuner to the strongest signal carrying that program. Traffic Program (TP): This symbol alerts you to the fact that the station you’re listening too regularly broadcasts special traffic information. Think of TP as the "indicator " for Traffic Announcement (TA).

RDS "Dynamic" services:

Traffic Announcement (TA): This is the active side of TP capability. This guarantees up-to-the-minute information sent to the driver. Radio Text (RT): This feature allows a broadcaster to send up to a 64-character message that could scroll across your radio’s display, things like sports scores, song titles, artist or album names, even advertisements. Clock Time (CT): An RDS-equipped station broadcasts a time and date synch signal once a minute. Emergency Alert System (EAS): PTY code # 31 If your RDS tuner senses an emergency code, it will flash an ALERT message.

The Function in RDS App

The RDS App has 4 Tabs: Name: Text: Time: Audio:. In the Current App V 1.4.3 only Name: and Text: are implemented. Key Items on each of the App tabs, that can be selected with the cursor and changed with the encoder knob are:

Common to all TAB

• Title bar: The usual items may be changed and displayed.
• Program Type: There are 31 pre-set Program types.
• Program ID: The Program ID is 4-character Hex from 0000 to FFFF.
• TP: This tick box select the sending of a Traffic Program Symbol.

At the Bottom of the App Page are settings related to the RF configuration these being:

• Frequency: At the lower part of the App is the Frequency setting. This is stored in persistent memory.
• Step size: This is next to the frequency, it allows the selection of the standard step sizes.
• Gain: The gain setting are below the frequency and marked (0-47) LNA(IF) and AMP 0=0db or 1=14dB.
• Start: This button starts the transmission, and if pressed again, can stop the transmission.

Name Tab

• Transmit PSN: The program service name can be sent if the tick Box is selected.
• PSN: This is the Program Service Name. This is added by selecting the Set Button. This brings up the text Keypad so the name can be entered. (maximum limit of 8 characters)
• Stereo: A tick box to select this function. (Not known if this works).
• Music: A tick box to select this function. (Not known if this works).
• Traffic Announcement: A tick box to select this function. (Not known if this works).

Text Tab

• Transmit Radiotext: This tick box enables the sending of Radio text.
• Set: The Set button brings up the Text Keypad and allows text to be entered up to 28 characters.

Time Tab

• Transmit Date & Time: This is a tick box to enable, but the page states that it is “Not yet Implemented”.

Audio Tab

• Transmit Audio: This is a tick box to enable, but the page states that it is “Not yet Implemented”.