Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!mailrus!iuvax!maytag!focsys!brad
From: brad@focsys.uucp (Brad McCloy)
Newsgroups: sci.electronics
Subject: Re: DTMF tones
Summary: Un-documented tones?
Message-ID: <1990Jul25.125339.1665@focsys.uucp>
Date: 25 Jul 90 12:53:39 GMT
References: <44900010@uxa.cso.uiuc.edu> <44900011@uxa.cso.uiuc.edu> <1202@gold.GVG.TEK.COM>
Reply-To: brad@focsys.UUCP (Brad McCloy)
Organization: Focus Automation Systems, Waterloo, Ontario.
Lines: 34

In article <1202@gold.GVG.TEK.COM> grege@gold.GVG.TEK.COM (Greg Ebert) writes:
>In article <44900011@uxa.cso.uiuc.edu> tds32845@uxa.cso.uiuc.edu writes:
>>
>>	What I mean is, I need the tones corresponding to the numbers, 0-9,
>>and the two special characters, * and #.
>
>1=697hz & 1209hz
>2=697hz & 1336hz
>3=697hz & 1477hz
>4=770hz & 1209hz
>5=770hz & 1336hz
>6=770hz & 1477hz
>7=852hz & 1209hz
>8=852hz & 1336hz
>9=852hz & 1477hz
>*=941hz & 1209hz
>0=941hz & 1336hz
>#=941hz & 1477hz
>
>(From National TP5395 / TP53125 data sheet)

There are also some minimum time durations for the tones:
Tone duration (min)     : 50mS
Time between tones (min): 45mS
Max f deviation         : 1.5%

  I also came across some undocumented but supposedly valid tones.
Anyone have an idea or care to guess what they do?
Fo = 697Hz & 1633Hz
F  = 770Hz & 1633Hz
I  = 852Hz & 1633Hz
P  = 941Hz & 1633Hz

watmath!focsys!brad