bci2000.org BBS

Hi, all

we now use: Neuroscan + P3SignalProcess + P3Speller as we did before,

Launch --> Config --> Set Config , everything worked pretty well...... except......when I clicked Start, nothing happened.

There is no flash of the letter matrix at all.

We meet with this problem couple days before, I fixed it by changing the "SampleBlock Size" from 16 to 8. But now we are already working with 8 sample per block, I don't know what else to do...

the only difference between current system and the system we used couple days before is that, signal source for Neuroscan now comes from a Linux PC instead of a windows one (we get rid of windows because its low efficiency). But I don't think that matters.

Any suggestion/idea/guess is appreciated.

Thank you very much.

Smile,
Lin

Lynn,

The Scan 4.3 program spits out data in specific block sizes, i.e., 40 at 1000 Hz and (I believe) 20 at 512 Hz. The SampleBlockSize parameter in BCI2000 needs to be set to the same block size.

Please post if this does not fix the problem. Clearly, this problem seems to be related to the data acquisition.

Gerv

gschalk wrote:Lynn,

The Scan 4.3 program spits out data in specific block sizes, i.e., 40 at 1000 Hz and (I believe) 20 at 512 Hz. The SampleBlockSize parameter in BCI2000 needs to be set to the same block size.

Please post if this does not fix the problem. Clearly, this problem seems to be related to the data acquisition.

Gerv

The original input is 1000HZ, but we down_sample it to 256 inside the Linux box, and send it the BCI2000. So in this case, we should set SampleBlockSize to 8, right? 8 is the default setting under 256HZ, and we didn't change it

Lynn,

I see. It is usually best to determine as much as possible where the problem comes from. I would start by running Scan 4.3 on the same computer as BCI2000 (i.e., on Windows) using 1000 Hz and a SampleBlockSize of 40. If this is not working, then your BCI2000 configuration has a problem (we have seen many groups use Neuroscan and it usually works for them, though), and we would be glad to help to fix it. Then, you can use your Linux box instead of direct connection to Scan 4.3. If this does not work correctly, then the Linux box does not properly simulate the Scan software. Thus, in this case, there is not that much we could do since we did not write the Linux software, and thus the problem would have to be fixed by whoever wrote the Linux software.

Gerv

Hi, Gerv

Thank you for your reply.

It's running now.

I make BCI2000 output something in the System Log window to see whether it's working well . P3Speller runs when I turned the my additional output off.

Thank you

Smile,
Lin