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From: mbutts@mentor.com (Mike Butts)
Newsgroups: sci.electronics
Subject: Re: automatic commercial deletion
Message-ID: <1989Sep20.161222.2230@mentor.com>
Date: 20 Sep 89 16:12:22 GMT
References: <1680@ns.network.com>
Distribution: usa
Organization: engr
Lines: 25

From article <1680@ns.network.com>, by logajan@ns.network.com (John Logajan):
> inc@tc.fluke.COM (Gary Benson) writes:
>> I mean, every station in the nation doesn't have a
>> dedicated engineer sitting there watching a clock count down and then
>> pressing his "goto local" button!
> 
> But that doesn't necessarily mean that such automatic signaling is
> available on the outgoing video/audio signal.  It could either be
> stripped off, or come over a completely independent channel.
> 
> I've often noticed, however, some touch-tone like sounds on cable
> tv broadcasts, such as from WTBS Atlanta, CNN etc.  I don't know what
> sort of information is being sent -- but it doesn't coorelated with
> the time commercials appear.
> 
> -- 
> - John M. Logajan @ Network Systems;  7600 Boone Ave; Brooklyn Park, MN 55428 -
> - logajan@ns.network.com, john@logajan.mn.org, Phn 612-424-4888, Fax 424-2853 -
I'm pretty sure the tones are used to signal the local cable distributor when a
time for inserting a local commercial is upcoming.
-- 
Michael Butts, Research Engineer       KC7IT           503-626-1302
Mentor Graphics Corp., 8500 SW Creekside Place, Beaverton, OR 97005
!{sequent,tessi,apollo}!mntgfx!mbutts         mbutts@pdx.MENTOR.COM
Opinions are my own, not necessarily those of Mentor Graphics Corp.