[Test-Equipment] Re: How to do Time interval on freq. Counter

[Gollum]

"Paul Cianciolo" <Paulc at snet.net> wrote:

>Do I not understand what is going on?   tThe assumption here is that if both
>signals are same freq. the diff should be zero??
>  
>
No. What you are measuring is the phase difference between the two. If 
they are on the same frequency,
the time interval  between the points where your counter triggers on 
each sinewave is just the phase difference
between the two, and it should generally change if you power cycle one 
or both oscillators.
If the frequencies are different, that value should continuously change, 
as the phase is the time-integral of
the frequency, and what you are really doing is to compute the 
difference between the two integrals, which
now are increasing at different rates.

Al