ADC control of NI adapter module

[XINGJIAN]

Hi,

For NI adapter module like NI 5751, it have 16 analog input channel and each channel have a individually ADC.

So my question is whether I can control each ADC seperately？

I just would like to let each ADC works with different start time (the first channel starts acquire and followed another)

Thanks!

[JakeA]

Hi XINGJIAN,

It sounds to me like you're interested in starting data aquisition for each channel at different times. You can control the timing for data aqcuisition of each channel independently, this can be done programmatically in LabVIEW.

I will also link you to the manual for the 5751 which should contain all the necessary information about the hardware.

Regards,

[XINGJIAN]

Hi Jake,

Many thanks to your answer! I think it is very useful.

And I still have a follow question: Could I make the difference between start time of each channel (ADC) be very small?

For example, If the sample time interval of each ADC is 10^-6 s(according to the max sampling rat of ADC), Could I make the difference between start time of each channel (ADC) be like 10^-7 s? Would it be limited by the clock in FPGA module or the sampling clock in adapter module?

The picture below is a indication of my question. From the picture, you can see the time offset betwen each ADC is really small (even smaller than sampling time interval).

Thanks!

Xingjian

[JakeA · Accepted solution]

Hi Xingjian, 

I believe that you will be limited by the slowest clock in the hardware system you are using. Because there are multiple clocks involved, if the rate of the slowest clock is slower than the smallest time interval you wish to use, then that will limit you on what you can do. The default clock in the 5751 runs at 50 MHz, or 2*10^-8. Does this answer your question?

Regards,

[XINGJIAN]

Thanks Jake. Your answer is useful and exactly to my question.