Buffer Overwrite Error -200141

[AirSea]

I am using an extension of the code called "Measure Buffered Semi-Period-Continuous.vi" from the example finder.  Inside the main while loop I have added some additional calculations before I return to DAQmx Read in the next iteration.  I am getting an error -200141 which states that "Data was overwritten before it could be read by the system."  Currently I have the "Number of Samples Per Channel" at 2 for the DAQmx Read input, but I am not sure if what I have done is correct for what I am trying to accomplish.  What I would like to do is pull only the first two points of the buffer each time I come to DAQmx Read.  The remainder of the buffer is not important and could be thrown away if possible.  When the next iteration of the while loop comes to DAQmx Read I would again like to read the first two points and so on.   Also I would like to know if there is a way that I could keep track of the size of the backlog of the data for future reference.
Thanks,
Nick

[falkpl]

See the producer consumer model of programming.  It is best to extend this program by adding a second loop(thread) and after reading your data send it to the analysis loop for processing with a queue.  The buffer overrun is due to the data not being raed from the buffer fast enough.  Your processing is slowing down your DAQ loop.

Paul

[McKala[DE]]

Hello Nick,

You can monitor the number of samples available to read using the DAQmx Read Property Node, under Status >> Available Samples Per Channel.  Also, here's a Tutorial on the Producer/Consumer Model.

Let us know if you are still running into problems after implementing that model.

Regards,
Micaela