waveform cursor movement problem

[Mathan]

Hai thanks a lot for all your support.

This is the actual measurement i need to do. So i first need to measure t1. For that, i took the envelope of the signal in the upper part which is in the waveform graph of the attached vi in the last post. I need to find 90% and 5% of it then.. This is the problem.

Any suggestions? Visualization is not required. I need to find/measure the exact values.

Thanks very much.

Mathan

Message Edited by Mathan on 10-30-2009 11:28 AM

[ThHagel]

Hi Mathan,

I guess you don't really want to visualize the measurement by animating the cursor, right?

If I'm right, try the t4_mod.vi

... 

[Mathan]

I can say you are the most brilliant. Thanks a lot. This is what i am expecting. You did it. 

[Edit: Thanks Thomas, today i learnt a lot about the waveform graph properties. Thanks for the timely help. When you have time can you show me a method how to measure the same using cursor movements. If possible you do it. Am not compelling. Thanks a lot again.] 

Mathan

Message Edited by Mathan on 10-30-2009 12:32 PM

[Mathan]

Dear Thomas,

But for a certain waveform obtained from the oscilloscope the 5% of the rising edge is not correct due to the envelope of the waveform. Kindly see the attached file. Any method to solve this problem?

Thanks a lot,

Mathan

[ThHagel · Accepted solution]

Hallo Mathan,

in fact the 5% position is detected correctly at the first rising edge that fits to the used Transition-Search parameters. But it's not the rising edge of your interest, so we need to adjust the parameters (reference level) in your waveform. If you increase the high ref level to 6 (previously 5.01) the search algorithm ignores edges with amplitudes less than 1%. Try this and you'll see it works even if smaller positive slopes are contained in your measurement waveform.

With that kind of measurement results you should adjust those level parameters in general to be less sensitive for small edges (the values we previously used are set up to be very sensitive).

Regards,

Thomas

[Mathan]

Dear Thomas,

Thanks a lot for the input. I'll try this with some other set of waveforms from the oscilloscope tonight and let me know you asap.