AD3 Maximum Buffer Size limited to 16K in Waveforms SDK

[Sam S.]

Hi all,

In the "AD3 Specifications" Document, the maximum sample buffer size is listed as 32K for two channels, or 64K for one. However, in the C SDK, FDwfAnalogInBufferSizeInfo returns 16384 as the maximum buffer size. Am I missing something? How can I capture 32K samples instead?

Thanks,

Sam

[JColvin]

Hi @Sam S.,

I'm guessing you're opening the Analog Discovery 3 in it's default configuration which assigns 16384 as the default configuration size for each of the analog input channels.

To open the second configuration (configuration 1 with the zero based index) you'll want to use the function "FDwfDeviceConfigOpen" instead of just "FDwfDeviceOpen".

So for opening the first available device in the second available configuration, you'll want

FDwfDeviceConfigOpen(-1, 1, &hdwf);

The built in device_enumeration.cpp example will list out all of the configurations for you.

Here's a forum thread on the same topic:

What I'm not certain on how to do is how you might allocate extra buffer that is associated with disabled analog channels to the remaining channel like you can in the application for the AD3.
Simply disabling the channels, reconfiguring the device, and then checking the available analog buffer size didn't seem to yield the 64k I was looking for when I tested it out in python..

I'm hoping the developer will offer some insight on how this might be done once it is regular work hours in his timezone.

Let me know if you have any questions.

Thanks,
JColvin