Post by thread:Seeking Information

At 10:21 AM 5/06/98 +0100, you wrote: >Hi, > >I am sorry to put my troubles to you, but I saw a previous e-mail that >did the same. > >I have been trying to obtain information on telephone dtmf translation, >in particular ascii character which represent keys such as Recall >button. > >I will be grateful if you can really help me with this. > >Regards >Anthony > > Look at MITEL app note MSAN-108, it ha the conversion of ASCII to 2 character DTMF Dennis -=====================================================================- Dennis Plunkett: Embedded Hardware, Software design NEC Australia DRMASS ph 03 9264-3867 -=====================================================================-

> Van: talkworld <spam_OUTtalkworldTakeThisOuTEASYNET.CO.UK> > Aan: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU > Onderwerp: Seeking Information > Datum: vrijdag 5 juni 1998 11:21 > > Hi, > > I am sorry to put my troubles to you, but I saw a previous e-mail that > did the same. > > I have been trying to obtain information on telephone dtmf translation, > in particular ascii character which represent keys such as Recall > button. > > I will be grateful if you can really help me with this. > > Regards > Anthony Hello Antony, DTMF is a way to send the numbers 0 thru 9, #, * and the special codes A thru D by way of dual tones. One tone represents the Row and one the Line (A 4-by-4 matrix). The intersection between these two represent the pressed key. The Recall button does not generate any DTFM code, but is a direct signal to the chip in your phone to (what else :-) redial the number it stored from the last time. Try disconnecting the phone, reconnect, and pressing the 're-dial' button. Most likely you will hear nothing, because the phone lost it's memory :-) because you took its power (the phone-line) away ... Greetz, Rudy Wieser

[SNIP] > >The Recall button does not generate any DTFM code, but is a direct signal >to the chip in your phone to (what else :-) redial the number it stored >from the last time. > You'll probably find that the Recall button doesn't redial the last number dialled, but presents the exchange with a signal telling it that it's services are required. There are several different types of recall, such as earth recall (Where one of the wires is shorted to earth), timed break recall (Where the circuit is interrupted for a short period of time) and a few others that I can't remember. Graham

At 01:02 PM 8/06/98 +0200, you wrote: {Quote hidden}>> Van: talkworld <talkworldKILLspamEASYNET.CO.UK> >> Aan: .....PICLISTKILLspam.....MITVMA.MIT.EDU >> Onderwerp: Seeking Information >> Datum: vrijdag 5 juni 1998 11:21 >> >> Hi, >> >> I am sorry to put my troubles to you, but I saw a previous e-mail that >> did the same. >> >> I have been trying to obtain information on telephone dtmf translation, >> in particular ascii character which represent keys such as Recall >> button. >> >> I will be grateful if you can really help me with this. >> >> Regards >> Anthony > > >Hello Antony, > >DTMF is a way to send the numbers 0 thru 9, #, * and the special codes A >thru D by way of dual tones. One tone represents the Row and one the Line >(A 4-by-4 matrix). The intersection between these two represent the >pressed key. > >The Recall button does not generate any DTFM code, but is a direct signal >to the chip in your phone to (what else :-) redial the number it stored >from the last time. > >Try disconnecting the phone, reconnect, and pressing the 're-dial' button. >Most >likely you will hear nothing, because the phone lost it's memory :-) >because you took its power (the phone-line) away ... Incorrect! Most phones use EEPROM to store this information, even though it is not required (Phone lines are consisderd as always powered). You will find (If RAM is used) that the time for the phone to disscharge is quite long, as it may not draw more than 50uA on average from the line (Austel TS002, TS003) Also DTMF is used to send information over radio links, and a standard table of DTMF to ASCII also exits. Dennis > >Greetz, > Rudy Wieser > > -=====================================================================- Dennis Plunkett: Embedded Hardware, Software design NEC Australia DRMASS ph 03 9264-3867 -=====================================================================-

At 11:01 AM 9/06/98 -0000, you wrote: >[SNIP] >> >>The Recall button does not generate any DTFM code, but is a direct signal >>to the chip in your phone to (what else :-) redial the number it stored >>from the last time. >> > >You'll probably find that the Recall button doesn't redial the last >number dialled, but presents the exchange with a signal telling it that >it's services are required. There are several different types of recall, >such as earth recall (Where one of the wires is shorted to earth), timed >break recall (Where the circuit is interrupted for a short period of >time) and a few others that I can't remember. > >Graham > > Yes you are right in one way, exchanges con now store phone numbers in Australia this is called "Easy call", however the functions are envoked using digits and the hash key. As for redial, this will be the number in the phone, if you press that key, you will here the number being dialed. Dennis -=====================================================================- Dennis Plunkett: Embedded Hardware, Software design NEC Australia DRMASS ph 03 9264-3867 -=====================================================================-

> Van: Graham Murphy <EraseMEGrahamMspam_OUTTakeThisOuTFCCTI.CO.UK> > Aan: PICLISTspam_OUTMITVMA.MIT.EDU > Onderwerp: Re: Seeking Information > Datum: dinsdag 9 juni 1998 13:01 > > [SNIP] > > > >The Recall button does not generate any DTFM code, but is a direct signal {Quote hidden}> >to the chip in your phone to (what else :-) redial the number it stored > >from the last time. > > You'll probably find that the Recall button doesn't redial the last > number dialled, but presents the exchange with a signal telling it that > it's services are required. There are several different types of recall, > such as earth recall (Where one of the wires is shorted to earth), timed > break recall (Where the circuit is interrupted for a short period of > time) and a few others that I can't remember. > > Graham That's true for older type telephone's (non-electronic one's) and 'phones linked to a local exchange facility. Nowadays the intelligence of the phone has risen somewhat. But you are right, I should have mentioned them also. Greetz, Rudy Wieser

>From: Dennis Plunkett[SMTP:@spam@dennisKILLspamRDD.NECA.NEC.COM.AU] >>>The Recall button does not generate any DTFM code, but is a direct signal >>>to the chip in your phone to (what else :-) redial the number it stored >>>from the last time. >>> >> >>You'll probably find that the Recall button doesn't redial the last >>number dialled, but presents the exchange with a signal telling it that >>it's services are required. There are several different types of recall, >>such as earth recall (Where one of the wires is shorted to earth), timed >>break recall (Where the circuit is interrupted for a short period of >>time) and a few others that I can't remember. > >Yes you are right in one way, exchanges con now store phone numbers in >Australia this is called "Easy call", however the functions are envoked >using digits and the hash key. As for redial, this will be the number in the >phone, if you press that key, you will here the number being dialed. Indeed, this is one of the things the exchange can do. However, if you are stuck with a two wire analog phone (as opposed to a key phone or somesuch!), you often find that the recall button will allow you to do things such as putting the caller on hold, transferring the caller to a different directory number, setting up a three way conference and other specialties you can't do without first letting the exchange know that you want the dial tone back! Graham

Dennis Plunkett wrote: > Yes you are right in one way, exchanges con now store phone numbers in > Australia this is called "Easy call", however the functions are > envoked using digits and the hash key. Pardon if I elaborate/ correct. "Easycall" is a complete *range* of facilities, not just number memories. You use the "hash", "star" *and* the recall key when you want to use the "recall" or similar "call waiting" facilities. Recall or "break" generates about 600mS of break which is a signal to the exchange that although you are on one call, you wish its attention to set up another parallel call or function. Otherwise, once the call is actually set up, all touch tones are simply piped to the other station for voice-mail and other "smart" functions. Cheers, Paul B.