We have a project for which I must collect at a 50kHz sample rate on several channels. This is higher than we have ever attempted before. I am running into some issues with dropped samples in my data files; I'm not getting as much data back as I expect.
The data is being collected on an RT system (PXI-1052 chassis with a PXI-8109 controller). I am using a PXI-6259 M-Series card connected to a set of SCXI-1143 filters. I am sampling below the maximum bandwidth of the filters (333 kS/s is their maximum, whereas I am sampling at an aggregate of up to 250 kS/s).
I'm doing a finite acquisition. My task is started and then I am running a timed loop inside of which I read all available samples, push them to an RT FIFO (for viewing purposes) and then write them to an ASCII file on disk. The loop iterates every 100ms. Since it's a finite acquisition my understanding is that my data should be buffered fully and nothing should be lost. The loop ends when the DAQmx task says that it is finished.
I don't get any errors back from NI-DAQmx, so it's hard for me to figure out where the data loss is happening.
