AnalogInRecord regression when recording small number of samples (on 3.23.3)

[positron]

Hello. Last week I've upgraded from WaveForms 3.18.1 to 3.23.3 and noticed a problem with SDK.

When I do oscilloscope record with a small number of samples (on AnalogDiscovery2 the threshold size is 8190), the recording loop reports all the available data on first iteration and the library immediately returns all the requested data, but filled with garbage. If duration of recording is measured, it is 0 seconds instead of n_samples/freq. Larger number of samples (8191+) perform correctly. I could reproduce it on Windows x64 and Debian x64.

The same program records perfectly well on version 3.18.1.

Here is a minimal example. It is a modified AnalogIn_Record.py program with added time measurement and number of samples set to 8190.(and frequency set to 4000, so it should take ~2s to record).

On 2.23.3 it takes 0s to collect data, on 3.18.1 it takes 2s correctly.

The pictures show how same code runs on 3.18 and 3.23 with capture duration and plot.

 

PS On Linux, 3.18 works correctly with both Adept runtimes I've tried, 2.26.1 and 2.27.7. 

 

digilent.py

[attila]

Hi @positron

Will be corrected in the next version, probably tomorrow.

For short captures better, up to device buffer size, use the default acqmodeSingle.
The acqmodeRecord uses data streaming and it is intended for longer and lower rate captures.

[attila]

Hi @positron

 

[positron]

Hi. I confirm it's fixed in the new version!