Scan and BCI2000

[kiddnesta]

Hi
I have connected BCI2000 and Scan for online analysis.
In the config Parameters,

SampleBlockSize
The number of samples transmitted at a time. The VisionRecorder appears to send one block each 40ms, so SampleBlockSize should match SamplingRate x 40ms.

So if the SamplingRate is 250Hz, SampleBlockSize is 10.
In the Matlab,the bci_InSignal's size is nx10,n is n channel.

Then my Matlab program must read data per 40ms.

How can increase the SampleBlockSize?
Or How do I write this program?