RDS是Radio data system。
作者: 发布:2012/6/3 浏览:972
RDS是Radio data system。 是一种可以显示电台名称的功能。
一般用户最常遇到的是AF（在欧洲非常普通， 是指相同电台节目在不同环境下用不同的频率广播）， 相同的电台会用一样的PI来辨识。比如同样的BBC news， 在德国， 瑞士都有广播， 但是用的频率不同， 但是PI相同， 当行者（驾车人）从德国到瑞士的时候， 如果你的收音机AF功能开启， BBC会从德国的频率跳到瑞士的频率， 而保证你收听的BBC不受干扰， 不间断。
同样的， 在不同的环境下， AF也会有别的用途， 比如汽车进入隧道， 随到外的信号接收不到， 隧道内会有AF 广播。
PS是指特殊广播服务， 比如，News， Weather， TA（traffice announcement）， 如果你收音机以上功能开启， 你的收音机会自动跳到此类广播。 这些广播通常是时间短暂， 周期性广播的。 比如新闻会每个正点头五分钟播放新闻头条。
Alternative Frequencies. This allows a receiver to re-tune to a different frequency providing the same station when the first signal becomes too weak (e.g. when moving out of range). This is often utilised in car stereo systems.
Clock Time. Can synchronise a clock in the receiver or the main clock in a car. Due to transmission vagaries, CT can only be accurate to within 100ms of UTC.
Enhanced Other Networks. Allows the receiver to monitor other stations for traffic broadcasts.
Programme Identification. This is the unique code that identifies the station. Every station receives a specific code with a country prefix. In the US, PI is determined by applying a formula to the station's call sign.
Programme Service. This is simply an eight-character static display that represents the call letters or station identity name. Most RDS capable receivers display this information and, if the station is stored in the receiver's presets, will cache this information with the frequency and other details associated with that preset.
Programme Type. This coding of up to 31 pre-defined programme types – e.g. (in Europe): PTY1 News, PTY6 Drama, PTY11 Rock music, – allows users to find similar programming by genre. PTY31 seems to be reserved for emergency announcements in the event of natural disasters or other major calamities.
Regional links. This is mainly used in countries where national broadcasters run "region-specific" programming such as regional opt-outs on some of their transmitters. This functionality allows the user to "lock-down" the set to their current region or let the radio tune into other region-specific programming as they move into the other region.
Radio Text. This function allows a radio station to transmit a 64-character free-form textual information that can be either static e.g. station slogans or in sync with the programming such as the title and artist of the currently-playing song.
Travel Announcements, Traffic Programme. The receiver can often be set to pay special attention to this flag and e.g stop the tape or retune to receive a Traffic bulletin. The TP flag is used to allow the user to find only those stations that regularly broadcast traffic bulletins whereas the TA flag is used to stop the tape or raise the volume during a traffic bulletin.
Traffic Message Channel. Requires an RDS-TMC decoder.