How to collect a sine wave using PCIe-6363?

[cainiao]

The board is an amplifier. It ouputs sine wave, I already measure the output with oscilloscope, it's correct.

[santo_13]

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@cainiao wrote:

Thank you sir, I connected BNC ground to the power supply, the wave appears. But here's another question: It seems that the wave is a bit distorted. How can I solve it?

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Your sampling rate may be low, trying increasing it to the max supported

[GerdW]

Hi cainiao,

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@cainiao wrote:

It seems that the wave is a bit distorted. How can I solve it?

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Did you notice my previous message?

What is your sample rate and what is the frequency of that sine wave?

[cainiao]

Hi, GerdW

The frequency of sine wave is 1kHz. Sample rate 9kHz. I think it obeys Nyquist theorem.

Cainiao

[santo_13]

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@cainiao wrote:

Hi, GerdW

The frequency of sine wave is 1kHz. Sample rate 9kHz. I think it obeys Nyquist theorem.

Cainiao

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Please keep in mind that Nyquist criteria preserve only the frequency and not the quality (i.e., shape). A 1kHz sine wave sampled at 2kHz will show up as a triangle wave after sampling.

You need to sample at 10x or more the frequency to acquire or generate a reasonable quality sine wave.

[GerdW]

Hi cainiao,

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@cainiao wrote:

The frequency of sine wave is 1kHz. Sample rate 9kHz. I think it obeys Nyquist theorem.

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Your first message told very different numbers!

Now you get just 9 samples per sine wave: what do you expect?

[cainiao]

Thanks for your reply. I will try later