Measure long trace using AD2 and WF_SDK

[abedbaltaji]

Hello everybody,

I am working on measuring a quite long signal using AD2 scope with the WF_SDK.

There is no much documentation on some details so I would like to ask how could I do the following:

- change the position of the trace so the trigger would be at the beginning of the trace and not in the center (so I can benefit as much as I can from the record of the buffer)

- apply samples offset (start record after specific number of samples)

- apply continuous recording, when I am calling the record function multiple time (and appending the buffer values to another list each recording) I am observing a lot of samples that are lost. So how can I minimize this lost of samples between a record and another.

 

Thanks in advance

[attila]

Hi @abedbaltaji

With the default device buffered acquisition mode acqmodeSingle the trigger position is set relative to the middle of the capture. The T0 to be at the first sample set this to capture time span/2, like:
dwf.FDwfAnalogInTriggerPositionSet(hdwf, c_double(0.5*cSamples/hzRate)) 
Use other values for different position.

With acqmodeRecord, data streaming for long capture at lower rates, with trigger position 0 the streaming is started at the trigger event.
With AD2 the record should work up to about 2.5MHz, depending on USB, system...

[abedbaltaji]

Would the acqmodeScanShift mode be better for long time acquisition? About 6 micro-seconds.

I want to stream them directly to the PC if possible. And the sampling frequency should be relatively high (20~50 MHz).

If yes, how to synchronize it with the trigger?

[attila]

Hi @abedbaltaji

With AD2 repeated captures up to 8192/16384 are supported at up to 100MHz and longer/continuous data streaming up to about 2.5MHz