Get the correct order of the tones for DTMF Decoder

Question

I am trying to decoder the DTMF stream signal (contains mutiple tones, delay, noise), however, I have the problem to seperate each tone in the stream signal in order to input into the Goertzel for further analysis. 
The phone number is 534-343-3436. At the input decoder, I do not know what is the phone number yet. However, I want to seperate 5 then 3 then 4 then 3....tone so I can put do the analysis on individual tone to know which tone is coresponding to what phone number.
Anyway I can archieve in LabView?
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Answer 1

There should always be an interval of no signal between tone pairs - otherwise you could not detect repeated values. For phone number 534-343-3333 you cannot just look for a change of frequency. Your signalling protocol must specify the minimum duration of a tone pair to be considered a valid signal and a minimum duration of no tone to be a valid separator between numerals. Maximum times are useful but not as important, except to determine how long the system will wait for a valid number.  The time settings may be dependent on the minimum tolerable signal to noise ratio.
So the algorithm would be something like this: Use amplitude discrimination to find the gaps between tone pairs. It does not need to be too good - it only needs to find approximate segments.It will use the timing specifications to set ranges of times to examine. Within each segment above threshold use the FFT to identify the tone pair. You could also use an FFT on the gap segments to verify that they do not contain a tone pair.
Also consider various errors. On Western Electric tone pads pressing two or more keys in one row or one column simultaneously results in a single tone. I have not looked at DTMF generators for some years so I do not know how how some of the IC-based generators handle that situation.
Lynn