Load capture buffer that was previously saved by the Nano


Just wondering if it would be possible to load a capture buffer that was previously saved by the Nano? If that is possible, could one then use the XA “Trig Pos” to scroll through the buffer and examine much more information than is provided in an IMG or REF file? The loading time would not be a concern while using this feature. It would allow users to exchange capture files that are more useful and you could also post examine your own files on the Nano in a more comfortable environment .

Yes there is an end to my suggestions! :slight_smile: I only have one more left to post.

Thanks for all your great improvements.

No need to be candid about posting requests – you may not get it all (from me at least), but that shouldn’t stop anyone from wanting! :slight_smile:

Short, yes - I think this is doable.

If this was (is) a hot request one might also consider alternatives.

  1. Create a PC viewer application (based on the current XML export format). Pros include bigger screen, no Nano resources required. Cons here are that requests may come from Windows, Mac, Unix and what not.
  2. Scrap the current reference format and replace with a full waveform. Pros include a much improved reference. Cons are we will have to reduce the sampling buffer on the Nano (e.g. from 4098 points to 2048).

Personally I use Excel for viewing the XML file. Point and click is all it takes to see a waveform graph. I have no idea if this is possible using the likes of OpenDoc.

I was looking at the Rigol DS1052 today ($400) and it reloads the buffer files. Basically it stops the acquisitions, changes the T/Div and V/Div to match the file and loads the file. As long as you don’t press the run key, you can scroll through the buffer, change the T/Div and use the measurement functions.

On the Nano ($89); as you well know, if I STOP the acquisitions or use a properly triggered Sing trigger mode, then all functions (except for 3) still work including cursor movement, measurements, trigger position, trigger level, and trigger sensitivity.

  1. Change of V/Div clears the screen but upon a new RUN the change is in effect.
  2. Change of T/Div clears the screen but upon a new RUN the change is in effect.
  3. Change of Probe Att clears the screen but still takes effect, probably for the same reason as V/Div above.

So maybe this function is not that far away from BenF reality.


  1. As you pointed out, the file viewer would require no changes nor Nano resources. Maybe someone on this forum can provide such an application for cross platform OS, or provide OpenDoc macro or equivalent. Another disadvantage is spontaneity. During my career of troubleshooting complex systems, it is often required to re-examine previous waveforms based upon new waveform findings.

If the buffer was saved to the SD card and then reloadable, you could easily back up to previous waveforms without reconnecting to those test points. You would just take snapshots along the way and review those as required. The REF wave limits you to the screen viewing area and offers none of the flexibility described above.

  1. I am not quite sure what you mean here. Are you talking about saving/loading the viewing area or the entire buffer?

I just used Excel for the first time, but haven’t figured out the graphing part yet. Thanks for the tip. I noticed 12 columns of repeating data and two columns of varying data. Does Excel cause this duplication or is that data in the file? Maybe you could include the sample time interval for those lazy folks amongst us that don’t want to do the math as described in your Manual. :unamused:

This would be as per your request, but rather than loading the buffer as the primary channel, we would load it as the secondary/reference channel. Panning the buffer would then move and display both channels. With this approach, imported data would survive past a new acquisition.

The data exported is exactly as the example in the user guide shows (you can also view the XML files in notepad to see the raw data). All relevant settings at the time of export (such as T/Div), are included so that a viewer application (or Excel) can display these as information fields. Numeric fields include everything a PC application would need for measurements (such as calculate Vavg, Frequency etc.) or to provide additional measurements/analysis not available directly on the Nano. The file however does not (and I think should not) include computed fields. This is what the viewer application should give us from the raw data.

OK now I get it, very interesting approach. If both are doable, then why not offer both options? Those users examining serial data could reload the primary buffer while in STOP mode, and those users examining limited waveform cycles could use the dual buffer approach for convenience. I really like that. :smiley: Once the user options for the split buffer, then all new acquisitions would use the 2049 byte portion of the split buffer. Otherwise all new acquisitions would continue to overwrite the 4098 byte buffer.

I guess these options would be best found in the XA pop-up menu; something like “Buf Load”, with choices of “Normal/Split” or some other words to that effect.

I must agree that you are absolutely correct in not wanting unnecessary info (such as sample interval) in the buffer file.