Measuring high frequency with NI 9411

[EETDer]

Hello,

I would like to measure the frequency of a TTL signal with the NI 9411 in a cDAQ NI-9178 chassis.  The frequency ranges from 1.6-48kHz.

With the digital frequency counter examples in Labview, it's not picking up on the signal.  Any advice?

Anna

[Eden_S]

Hi Anna,

Could you tell me the name of the example VI that you are using? Also, you say that it is not picking up on the signal. Are you getting no data from the device at all? If this is the case, have you tested the device in MAX to make sure that this is not a hardware issue?

Thank you,

[EETDer · Accepted solution]

Hello!

After speaking to an NI applications engineer, I realized that the signal input has to be less than 5V.  In particular, the low is between 0-0.8V and the high is between 2-5V.

Once I restricted the input signal to that range, the counter frequency module picks up on the signal very well.

Thanks,

Anna