Extended Data Services (now XDS, previously EDS), is an American standard classified under

Electronic Industries Alliance The Electronic Industries Alliance (EIA; until 1997 Electronic Industries Association) was an American standards and trade organization composed as an alliance of trade associations for electronics manufacturers in the United States. They devel ...

standard CEA-608-E

for the delivery of any ancillary

data In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted ...

(

metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

) to be sent with an

analog television Analog television is the original television technology that uses analog signals to transmit video and audio. In an analog television broadcast, the brightness, colors and sound are represented by amplitude, instantaneous phase and frequency, ...

program, or any other

NTSC The first American standard for analog television broadcast was developed by National Television System Committee (NTSC)National Television System Committee (1951–1953), Report and Reports of Panel No. 11, 11-A, 12–19, with Some supplement ...

video signal Video is an electronic medium for the recording, copying, playback, broadcasting, and display of moving visual media. Video was first developed for mechanical television systems, which were quickly replaced by cathode-ray tube (CRT) systems ...

. XDS is used by

TV station A television station is a set of equipment managed by a business, organisation or other entity, such as an amateur television (ATV) operator, that transmits video content and audio content via radio waves directly from a transmitter on the earth ...

TV network A television network or television broadcaster is a telecommunications network for distribution of television program content, where a central operation provides programming to many television stations or pay television providers. Until the mid-1 ...

s, and

TV program Television, sometimes shortened to TV, is a telecommunication Media (communication), medium for transmitting moving images and sound. The term can refer to a television set, or the medium of Transmission (telecommunications), television tra ...

syndication Syndication may refer to: * Broadcast syndication, where individual stations buy programs outside the network system * Print syndication, where individual newspapers or magazines license news articles, columns, or comic strips * Web syndication, ...

distributor A distributor is an enclosed rotating switch used in spark-ignition internal combustion engines that have mechanically timed ignition. The distributor's main function is to route high voltage current from the ignition coil to the spark plugs ...

s in the US for several purposes. Here are some of the most common uses of XDS: * The "autoclock" system delivers

time Time is the continued sequence of existence and events that occurs in an apparently irreversible succession from the past, through the present, into the future. It is a component quantity of various measurements used to sequence events, to ...

data via an XDS "Time-of-Day Packet" for automatically setting the

clock A clock or a timepiece is a device used to measure and indicate time. The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units such as the day, the lunar month and the ...

of newer TVs &

VCR A videocassette recorder (VCR) or video recorder is an electromechanical device that records analog audio and analog video from broadcast television or other source on a removable, magnetic tape videocassette, and can play back the recording. ...

s sold in the US. Most

PBS The Public Broadcasting Service (PBS) is an American public broadcasting, public broadcaster and Non-commercial activity, non-commercial, Terrestrial television, free-to-air television network based in Arlington, Virginia. PBS is a publicly fu ...

stations provide this service. * Rudimentary program information which can be displayed on-screen, such as the name and remaining time of the program, *

Station identification Station identification (ident, network ID or channel ID or bumper) is the practice of radio and television stations and broadcast network, networks identifying themselves on-air, typically by means of a call sign or brand name (sometimes known, ...

, *

V-chip V-chip is a technology used in television set receivers in Canada, Brazil and the United States, that allows the blocking of programs based on their ratings category. It is intended for use by parents to manage their children's television view ...

content rating A content rating (also known as maturity rating) rates the suitability of TV shows, movies, comic books, or video games to this primary targeted audience. A content rating usually places a media source into one of a number of different categories, ...

s data. XDS is also used by the American TV network

ABC ABC are the first three letters of the Latin script known as the alphabet. ABC or abc may also refer to: Arts, entertainment, and media Broadcasting * American Broadcasting Company, a commercial U.S. TV broadcaster ** Disney–ABC Television ...

for their

Network Alert System Network, networking and networked may refer to: Science and technology * Network theory, the study of graphs as a representation of relations between discrete objects * Network science, an academic field that studies complex networks Mathematics ...

(NAS). NAS is a one-way communication system used by ABC to inform and alert their local affiliate stations across the US of information regarding ABC's network programming (such as program timings & changes, news special report information, etc.), using a special decoder manufactured for ABC by

EEG Enterprises Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex ...

br>
a manufacturer of related equipment for the TV broadcast industry such as

closed captioning Closed captioning (CC) and subtitling are both processes of displaying text on a television, video screen, or other visual display to provide additional or interpretive information. Both are typically used as a transcription of the audio por ...

and general-purpose XDS encoders. The

CBS CBS Broadcasting Inc., commonly shortened to CBS, the abbreviation of its former legal name Columbia Broadcasting System, is an American commercial broadcast television and radio network serving as the flagship property of the CBS Entertainmen ...

Television Network uses a similar method to transmit three separate internal messaging services to stations: one for programming departments, one for master control operations, and one for newsrooms. Many standard definition receivers produced by

Dish Network DISH Network Corporation (DISH, an acronym for DIgital Sky Highway) is an American television provider and the owner of the direct-broadcast satellite provider Dish, commonly known as Dish Network, and the over-the-top IPTV service, Sling TV. A ...

encode XDS data into their output signal. Data encoded includes time of day, program name, program description, program time remaining, channel identification, and content rating. This data is obtained from the satellite service's

EPG Electronic programming guides (EPGs) and interactive programming guides (IPGs) are menu-based systems that provide users of television, radio and other media applications with continuously updated menus that display scheduling information for ...

and replaces any data which may have been present when the signal was uplinked. XDS uses the same line in the

vertical blanking interval In a raster scan display, the vertical blanking interval (VBI), also known as the vertical interval or VBLANK, is the time between the end of the final visible line of a frame or field and the beginning of the first visible line of the next fram ...

(NTSC line 21), and shares the available second

video field In video, a field is one of the many still images which are displayed sequentially to create the impression of motion on the screen. Two fields comprise one video Film frame, frame. When the fields are displayed on a video monitor they are "Interl ...

bandwidth with the closed captioning channels CC3 and CC4, and with the text channels TXT3 and TXT4.

External links

Does anybody really know what time it is?
- Faults & Failures October 2000 IEEE Spectrum - about some failures in the autoclock system in 2000 {{Video formats Television technology Standards of the United States