Dear all, I am using the 6602 board and the DAQmx "count_digital_events_buffered_continuously_Ext_clk.vi" to realize the photo counting. I have set up two counters, one is for input signal, another is for sample clock use. the data could be displayed either in a Graph or written to a file. (Graphic display/file store) The input signal has a frequence around 1MHz, I would like to set my sample Clock frequence as high as 1MHz. following are my problems: 1. I always encounter an error called: " Data was over written before it could be read by system". I have tried to give it a large sampling rate and a large "# samples to read" but the error could not be avoided. this happens when the Sample clock frequence exceeds 100KHz in Graph display and exceeds 10KHz in file store mode. 2. sometimes another similar error happens: "Attempted to read sample that are no longer available. they are previously available but have been overwritten". I am not sure what is the difference, but still, whatever I do, I was not able to get rid of that. My goal is to sample my signal at a frequence of 1MHZ. any suggestion would be welcomed.:) Qi

Counter/Timer

Counting Problem: How to avoid data overwritten?

Hi all,

I'm also working on my counter recently. The last tip (#7) sounds very interesting to me since I have been using CIDupCountPrevent all the time as told by a previous collegue. I'm using DAQmx and 0 count is a possible value for my measurement. Could anyone tell me why I'm not supposed to use CIDupCountPrevent in this case? Or could anyone show me a documentation for CIDupCountPrevent function which I have failed to find?

Thank you!

Yan

Message 21 of 21

(2,137 Views)

Counter/Timer

Counting Problem: How to avoid data overwritten?

Re: Counting Problem: How to avoid data overwritten?