Question on the waveform generation of NI USB-6211 DAQ device

[XunZou]

Hi,

I want to implement a simple function using the NI USB-6211: using an analogue output to generate a sine wave (0.1Hz to 10Hz) and sample the sine wave using one analogue input. My VI is attached below.

I use the DAQ assistants to generate and acquire signals while using the 'Simulate Signal' function to produce the sine wave. When I set the frequency of the sine wave as an integer, there is no problem with the acquired signal. However, if it is not an integer (1.5Hz, 5.4Hz etc), the acquired signal is not continuous. I have used an oscilloscope to test it and it is AO that generates discontinuous waveforms. Why is it discontinuous and what should I do to solve the problem?

 

[Vineet_A.]

Hello,

This knowledgebase article might be helpful for you:

Using the Simulate Signal Express VI to Generate Waveforms - NI

Based on the screenshots, you might want to play with different signal generation settings, like using continuous generation, generating an integer number of cycles, and simulating acquisition timing.

I didn't open the VI, but you could also put the generation function and the acquisition function into two separate loops, so the different timing doesn't impact each other.

Regards,

Vineet 

[XunZou]

It does solve the problem, thanks!