- Extended Data Services
Extended Data Services (now XDS, previously EDS), is an American standard classified under
Electronic Industries Alliance standardCEA-608-E [http://www.ce.org/Standards/browseByCommittee_2523.asp] for the delivery of any ancillarydata (metadata ) to be sent with ananalog television program, or any otherNTSC video signal .XDS is used by
TV station s,TV network s, andTV program syndicationdistributor s in the USA for several purposes.Here are some of the most common uses of XDS:
* The "autoclock" system delivers
time data via an XDS "Time-of-Day Packet" for automatically setting theclock of newerTV s &VCR s sold in the USA. Most PBS 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 ,
*V-chip content rating s data.XDS is also used by the American TV network ABC for their
Network Alert System (NAS). NAS is a one-way communication system used by ABC to inform and alert their localaffiliate stations across the USA of information regarding ABC's network programming (such as program timings & changes, news special report information, etc.), using a specialdecoder manufactured for ABC byEEG Enterprises [http://www.eegent.com] , a manufacturer of related equipment for the TV broadcast industry such asclosed captioning and general-purpose XDSencoder s.XDS uses the same line in the
VBI as closed captioning (NTSC line 21), but it utilizes the second video field (as opposed to closed captioning's line 21, field 1).External links
* [http://www.csc.uvic.ca/~csc454/notes/fault.vcrtime.html Does anybody really know what time it is?] - Faults & Failures October 2000 IEEE Spectrum - about some failures in the autoclock system in
2000
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