Measure time between two signals.

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Rednecknerd
Newbie
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Joined: Mon Apr 28, 2014 7:48 pm

Measure time between two signals.

Post by Rednecknerd »

I have a 4262 scope.
I need to measure the time between channel a falling to zero and channel b falling to zero.
This is a fairly common measurement in most scopes.
I know i can use the cursors to manually measure between them, but i need to capture and average several test points.
My signal is not stable enough to just move the cursors over the signal and saving and going back is very time consuming.

I was wondering if this math channel formula could be modified to meet my needs?
It was given to someone to measure phase shift in degrees. My measurement is similar to phase shift but is ms time instead.

acos(integral(A*B)/(sqrt(integral(A*A))*sqrt(integral(B*B))))/Pi*180

Karunen
Advanced User
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Posts: 194
Joined: Thu Nov 21, 2013 9:22 am

Re: Measure time between two signals.

Post by Karunen »

Hi,

You could use
(acos(integral(A*B)/(sqrt(integral(A*A))*sqrt(integral(B*B))))/Pi*180)/(freq(A)*360)

to calculate the time interval.

Unfortunately this is only suitable if the signals have the same frequency.

Please note as frequency requires zero crossing you might need to offset the signal,
for example freq(A-0.25).

Another thing to note is at the beginning of capture the phase calculation is incorrect as it does not have enough data
and the frequency has no values at the beginning and the end of capture because it does not have enough data.

Thanks,
Karunen

Technical Specialist
Pico Technology

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