MSO/DPO5000/7000 Series and MSO4/5/6 Series Single Acquisition Keep History

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

On the 4/5/6 Series scopes, the measurement system does keep the statistics of consecutive acquisitions (provided no configuration changes were made between acquisitions).  To see the accumulated statistics, simply add a Measurement Results Table.  You can do this by clicking/tapping the "Results Table" on-screen button in the upper right corner of the display, and then selecting Measurements.  On the result table, there will be two sets of statistical data (mean, min, max, stddev, population). The set to the left are the "local" stats, which are updated with each acquisition.  The set to the right are the running accumulated statistics.

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


 

Hi Michael,

I do not believe the 5000/7000 have an equivalent option to "Enable Acquisition History". You can change the acquisition mode to Envelope, Average or WfmDB, but then you won't have measurement statistics.

Instead, I would suggest a workaround: set trigger mode as Normal, when ready to take a measurement press Run/Stop to enable acquisition and press it again after your event was acquired. Repeat as many times as desired.
If you have several possible trigger events within a few seconds but only wish to trigger on the first one, then you can setup A->B sequence triggering to have a delay of up to 8 seconds, giving you enough time to press Run/Stop before the next event.

If this workaround doesn't do what you need to do then probably the next solution to try would be to use remote control programming (SCPI commands) to automate the process of gathering measurement data and generating the statistics on a PC.
TekScope Utility can log this data automatically after a single shot trigger event and save it as a .csv.

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 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 Mike,

I apologize, I was not very clear with my explanation of the workaround.

The AB trigger works by first waiting for the A trigger, then waiting the configured trigger delay period and then acquiring when B trigger conditions are met.

I suggest configuring A trigger to Edge trigger type and Line as source (this generates a trigger event to start the 8 second countdown). Then B trigger should be configured to trigger on your waveform of interest.

This means that, with trigger delay set to 8 s, you will have at least an 8 second delay between hitting Run/Stop and your acquisition. You will also have another 8 seconds before the next acquisition, giving you time to press Run/Stop again to stop acquisition.

This is not the most elegant workaround, if you have more information about your expected waveform then it might be possible to configure the trigger system to not need so much manual input.

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