bci2000.org BBS

Hi everybody,

I'm trying to build a source module for my NI board (NI-9215, it's a usb board). I'm using NIDAQ_mx signal source. After setting correctly my terminal configuration and other parameters like the data format, my BCI2000 system seemed to work fine, at least my data was displayed right while performing an acquisition. But then I realized that I had an issue with saved data, in fact even if I use the original version of NIDAQ_mx code, when I open my saved data using the BCI2000 Viewer, this data is not correct, it looks like it is composed only of noise and the duration of acquisition doesn't match the actual acquisition time.

Why is this happening? Why can I perfectly visualize my signals during an acquisition and then when these signals are saved they are probably stored in the wrong way (or using a wrong data format)?
How could I fix this?

Thanks for your help
Alessandro

Hi,
after some time spent debugging the code I realized that all my problems were related to data type conversion issues.
Specifically, my A/D board digital output is a 16 bit unsigned integer and so all the acquisition part of the code must manage my data as unsigned integer. Then I converted this data to int 16 before passing it to the rest of BCI2000 structure.
Now everything works fine.

Alessandro

Hi
I am using NI Elvis II for data acquisition in BCI2000, please tell me how could I use it?, should I have to build a module for its interface with BCI2000 ?


Muhsin