ni usrp 6351. Acquire/generate analog voltage

[tucoi98]

Hi all,I am trying to acquire the analog voltage of a signal and I'm wondering how I can use the source input of the DAQmx Timing (Sample clock) VI to get a high sample rate considering that the maximum sampling rate of the NI-USRP 6351 is 1.25 MHz. In my application I need to have more samples/bit

I'm also wondering how (if possible) I can generate a differential signal using this DAQ. I know it is possible to acquire a differential signal but not sure if the generation can also be done.

Thanks a lot in advance

[Dennis_Knutson]

It is the PCIe 6351. I don't know where you are getting USRP as that is completely different hardware and software.

What sample rate do you need? If the 6351 is not fast enough, why was it purchased?

No, it does not have differential outputs. You would have to do this with external circuitry.

[tucoi98]

Hi Dennis_Knutson

Sorry, I meant USB instead of USRP.

It was purchased for another application

How could I do it with external circuitry? Could you give me some ideas or references in which I can read how to do it?

Thank you

[Dennis_Knutson]

I know that there is the ability to provide an external clock but I don't know what the maximum rate is for that or whether you can exceed the internal clock rate. Have you looked at the manual and specs?

[John_P1]

With regards to your sample rate question, the spec is only 1.25 MHz.  In practice you might be able to go a little faster than this (even using the internal sample clock), though if you're looking for a significant increase in sample rate you'll need to select a different product that meets your specifications.

When the rate exceeds a certain threshold you will encounter an ADC conversion error (-200019), which happens if the sample clock edge occurs before the previous ADC conversion has completed.  You'll have to experiment to find the absolute max rate, I don't know off the top of my head.

Best Regards,

[tucoi98]

Hi Dennis_Knutson and Dennis_Knutson,

Thanks for your responses.

I'd also like to know how I can generate a differential signal from the DAQ. Do you have any idea? Dennis_Knutson you suggested using external circuitry. Could you elaborate a little bit more your answer, please?

Thank you!

[Dennis_Knutson]

Google 'single ended to differential'. Numerous devices from several vendors.