Continuous fetching from multi channels problem

[sonik1428]

I'm trying to acquire data continuously from 8 channels with PXIe-5105, and then save it to file with TDMS. My program is based on the example Fetch Forever. The problem here is that the fetched data is wrong. Only the data of channel 0 is right, the others are all wrong. It has something to do with the timeout of the Fetch VI. If I change the timeout to a positive value, the data is ok, but I cannot use all of 8 channels with NumOfSamples of 1MS and SampleRate of 1MHz. The error is "Data is overwritten and cannot be saved". I attached the program so that you know what I'm talking about. Hope you can help me get out of this problem.

[sonik1428]

Anyone?

[sonik1428]

Sorry, the attachment is failed to be uploaded. Here it is, again.

[Misic@NI]

Hi Sonik,

in my oppinion you have to set a timing in your while loop which should not be smaller then 1/freq.
Look at the screensot i attatched.

Regards

Matijas

[sonik1428]

Thanks for your concern.

But it does not solve the problem.

[sonik1428 · Accepted solution]

Ok, I have found the solution. I have to reduce the number of samples per channel. 1MS x 8 channels + overhead is more than the onboard memory, which is just 16MB.

Thanks for helping me.

[Misic@NI]

Thank you for informing me that you found the solution.