If I need to measure 15mhz sine and 10mhz square wave, how to choose DAQ board?

[AAA888]

If I need to measure 15mhz sine and 10mhz  square wave, how to choose DAQ board?

[Online_Courses]

Hello AAA888,

In order to choose a card that can acquire both a 15MHz sine wave and 10MHz square wave, you will need to choose a card that has at least twice the sampling rate of the signals. The reason for this is the Nyquist Theorem. This value will only allow you to acquire the signal frequency but if you want to get a clear signal than you will need to acquire around 5 to 10 times faster than your signal. Knowing this, here are the devices I would suggest.

From here, you will need to choose the resolution, bandwidth, form factor (PCI, PXI, USB), etc you need for your application.

[AnalogKid2DigitalMan]

Are we talking milli (mHz) or Mega (MHz) hertz?

-AK2DM

[Henrik_Volkers]

10 -15mHz frequency measurement:

You didn't talk about the needed resolution and update speed 😉

For the analog sine: sample about 1 period with 10 SPS and use the tone detection vi.  More tricky things can be done to get a higher update rate ...  a sine approximation can give good results with only half a period , however more details are needed (pure sine? Offset? Stable amplitude?)

For the digital signal and low frequency you usually use a counter . Counter size (usually 32 bit) and counter frequency (here quite low) must fit for such low f .