Function LabVIEW to acquire high-frequence data

[huyc]

Hi,
Actually, in a program created with LV 4.1, we use "AI Sample Channel" in a while loop to acquire data from 3 channels on a PCI-6025E card. But the frequence is limited to about 0.08s. Now, we try to port the program to LV 6.1. My question is what the function in LV we should use to perform acquisions at highest frequence. We found "AI Acquire Waveforms" in LV's standard library, but it implies a lots of modifications and we don't know if it's the fastest method.

Thanks.

[huyc]

In my question above, please, replace "frequence" by "same rate". Thanks.

[PdB]

I would advise you to study the data acquisition examples and the manual of LV.
By using another way of doing DAQ, together with a slight modification of your program, your are able to at least a 10 or 100 times increase in throughput.
The trick is that you don't have to re-initialise all channels, sample-rates,gains, etc, etc. when doing DAQ. This is what happens when you use some of the basic DAQ input vi's, but these are not intented for measuring data in a fast repeating way.
Just let your LabVIEW application sample the 3 channels as a background job.
Reading out buffers will give you the acquired values, one of the powers of NI-DAQ.

Patrick de Boevere