PXI-7831R analog input max sampling rate?

[plf]

I'm using 5 of the analog inputs on the 7831R and seem to only be able to get a max sampling rate of 10K per channel. Looking at the specs it should do at least 10 times this per channel, also the time for the A/D loop is 228 ticks of the 40MHz clock so this would suggest a higher sampling rate than just 10K. I'm missing something here... Any ideas as to what the deal is?

pete

[Prashanth]

Hi Pete,

You are right in saying that the 7831R boards should acquire data much faster than 10KHz. Infact you can take a look at the actual specs from the data sheet https://www.ni.com/en-us/support/model.pxi-7831.html as well as the product manual. However, I am concerned that you may be measuring the rate of acquisition on the RT VI (or any host vi) you are running as opposed measuring it in the FPGA VI.

Your time critical loop may be running at 228 ticks of the 40 MHz clock but the data is buffered (at that rate) and has to be then transferred to the communication loop which then sends the data to the host vi (which may be your RT vi). Hence, the rate at which host VI receives the data will be much slower than the FPGA VI is acquiring data.

Hope this helps!

Prashanth