6320 slow ADC read

[mwalczak5603]

Hello,

I am using a PCIe-6320 that I am polling the ADC, in a very simple while loop.  The time per iteration of the while loop is approx. 9 millisec. While the interation time of the while loop without reading the DAC is 10 microseconds. That is huge difference.  Any thoughts, I am trying to poll at about 4 kilohertz which I would think would not be a problem.  BTW I am only reading one channel.

Regards,

Mike

[Mcdan]

Mike,

Are you calling DAQmx Start prior to the loop which performs your read?

Dan

[Dennis_Knutson]

Besides reading only one channel, how are you reading it. If you doing something like 1 sample mode, then you are doing software timed acquisition and that is very slow. If you are doing continuous acquisition, then your loop rate is a function of your sample rate and the number of samples. It's simple arithmetic.

[mwalczak5603]

Yes

[mwalczak5603 · Accepted solution]

Software, let me give harware timed a try.  Thanks.  It just seems so odd that just doing a simple read would take so long.

[Mcdan]

One other thing that you may want to try for your software timed task.  In the DAQmx Channel Property Node, navigate to Analog Input->General Properties->Advanced->Data Transfer And Memory->Memory Mapping for Programmed IO Enable.  Set this property to true.

Dan

[mwalczak5603]

That's cool I will try that too.