analysis of signals acquired by oscilloscope

[lolob]

Dear all,

I would like to know if it's possible to analyze 2 signals (CH1 and CH2) acquired by an oscilloscope on LabWindows/CVI. The 2 signals are a sequence of square pulse.

The analysis I would like to be able to do is:

-Begin the acquisition on the first pulse of CH1

-Measure the delay between the first pulse on CH1 and CH2

-Measure the rise time, the fall time, the time high, the time low and the levels of each pulse on each channel

-Count the number of pulse on each channel

I would like to automate all those measurements. Is it possible?

How could I do it with the driver of the oscilloscope?

Thanks,

Laurent

[MJF]

Of course this sort of thing can be done. Now the question is, where do you wish to do this processing? Most digitizing scopes on the market today (including the low-cost ones) can do most of this internally so you can just query the scope for a measurement. (Rise-time, fall-time, pulse-width, etc. are common measurements, delay and pulse count may or may not be there).

The alternative is to capture the waveforms and then analyze them yourself.

None of what you want to do is particularly difficult. It's all just a matter of going through the waveform buffer and identifying the signal features you wish to measure.

[lolob]

Thanks a lot Martin.

But I still have a question.

It's possible to measure the rising time, falling time, high level, low level on a periodic square pulse or on a sequence with one square pulse.

But is it possible to measure all those parameters on a sequence of several different square pulse (different levels and timings) in an automated way?

I believe it's possible to do it manually by selecting each pulse with cursors, but is there an automated way to do it on LabWindows?

I explain the situation:

I have a sequence of 3 different square pulses and I triggered the scope to begin on the rising edge of the first pulse. So I have a scope window with the 3 square pulses.

Then I would like to automatically measure all the parameters of the 3 square pulses. Is it possible on the scope (Tektronix TDS640A)? Or is it possible on LabWindows by acquiring the waveform?

Thanks,

Laurent

[MJF]

Possible? Sure. I am certain the code to discriminate the individual pulses could be written. I doubt that the scope has that capability directly

I could certainly write this code if I had time to do it, it isn't a trivial task but it is also not too difficult.

What you can do is analyze the buffer to discriminate when each pulse begins and ends and then you can use that window into the buffer to do the measurements.