Michael Chwang

Hi Afonso,<br> <br> Awesome, let me try this out.<br> <br> Also, I have to apologize, I should have lead with my use case first before diving straight into asking about waveform search results.<br> <br> I hope you have some other suggestions before I try the search table functions...basically, I need to measure time delays for my HDMI signals, but I am noticing the delay function is giving me erroneous readings depending on the waveforms.<br> <br> I have 2 main from sources I am measuring from, HPD and DDC SCL.<br> When I am measuring from HPD Falling , I noticed if I set the 'to' waveforms (SCL, SDA, TMDS) to search backwards, the problem goes away<br> <br> However, if I measure from DDC SCL (should be last output, so look starting from the right) to compare it against the 'to' waveforms, I cannot get a good measurement. I think this is due to multiple edges occurring in both pre and post trigger.<br> <br> I can't seem to get this to work with the existing measurement system and have to use edge search to find the last edges of both 'from' and 'to' waveforms to calculate the timing difference.<br> <br> I am not sure if you have any suggests I can try before dealing with the search table solution? Preferably, if I can get away without setting the HPD measurements to backwards that would be a bonus as I am trying to main interoperability between different scope models and makers and some scopes don't have a backwards 'to' search function.<br> <br> Regards,<br> Mike<br> <br> &#160;

Hello,<br> <br> If I setup a waveform edge search, how can I readback the the result or pin point a particular result?<br> <br> Maybe for example, if I want to read the time location of the last rising edge found from a waveform search?<br> <br> I can't seem to find any SCPI commands that lets me index through a result array or transfer a result array over to the host computer.<br> <br> Regards,<br> Mike

Hi Afonso,

Ah ok, I get it. Unfortunately, that use case will not work. I think I will implement a simple array to keep track of the single acq readings and do the stats in software.

Thanks,
Mike

Hi Afsonso,

The AB Sequence trigger doesn't seem to work? It won't acquire any data if I start trigger with Run or Single then Stop. It must wait the max 8s before data is acquired.

Am I doing something wrong?

Regards,
Mike

Hi Afsonso,

Thank you for the great suggestions. I will try the AB Trigger with a long delay. I think that would be a suitable work around for now. If we run into an issue, then yes, like you suggested, we would need a sw solution to keep tabs on the measurements and do the statistics in code.

Thanks again!
Mike

Hi Alan,

This is not the behavior I am seeing on the 456 scopes. This works if it on auto trigger or continuous trigger, but not single trigger after single trigger.

Randomly testing things out I just saw an option called "Enable Acquisition History" that seems to have solved my problem on the MSO456 at least. This is reflected in the SCPI command "HORizontal:HISTory:STATe" Enabling this option will allow the measurement stats to accumulate as I expected.

Do you know if such an option exists on the 5000/7000 series? I don't have access to one of these models at the moment.

Thanks!
Mike


 

Hello, 

For our lower cost DPO4000 series and our Lecroy scopes, when we do multiple single acquisitions in series, the captured waveform will be logged as part of the measurement statistics. However, with the 5000/7000 and MSO 4/5/6 series scopes, I noticed that each single acquisition will clear the old data and the statistic count is always 1. Is there a way to prevent this from happening in the 5000/7000 and MSO4/5/6 series? I want each multiple single acquisitions to be counted in the measurement statistics. These are with the scopes' acquisition mode in `Sample`.

I tried looking into the user guide and programming manual to see if there were some settings I missed, but didn't find any.

Thanks!
Mike

BTW, this issue still persists in this version of the FW. We can duplicate it consistently in with both Labview and Python (PyVISA)

https://forum.tek.com/viewtopic.php?f=610&t=142995

This have moved onto using the ethernet interface instead of USB.