Real time aquisition of EEGdata through TCP server
Posted: Mon Jul 23, 2007 5:31 pm
Hello,
We have tried to acquire EEG data with TCP server of ActiveVIEW. We have observed a huge delays more than 100ms (at least 10% of the time) in reading a data of the size of the TCP array. Is it normal?
We have done the above experiment with following conditions.
1) Sampling rate set to 512 Hz.
2) Number of electrodes considered 32+1 or 64+1 (both the cases tested)
3) Reading of the TCP IP data is done with Instrument control toolbox of MATLAB on another computer
3) We tried increasing the input buffer size in the client side
4) The delay in reading is computed using psychtool box(MATLAB)
5) The Laptop connected to BioSemi system is with P4, 2Ghz. And the client is P4, 512RAM, 2Gz.
6) We are using ActiveVIEW Laptop 6.03 version
7) Both the computers are directly connected and isolated from the rest of the network.
Will all the above settings, We have observed a consistent delay in reading the packets.
Apart from the delays, we have observed a flicker in the raster scan-line once as soon as we establish the TCPIP connection, and continues to flicker until the connection is closed. Is it normal?
Can we reduce delays
Thanks in advance,
regards,
Gangadhar, IDIAP Research Institute.
We have tried to acquire EEG data with TCP server of ActiveVIEW. We have observed a huge delays more than 100ms (at least 10% of the time) in reading a data of the size of the TCP array. Is it normal?
We have done the above experiment with following conditions.
1) Sampling rate set to 512 Hz.
2) Number of electrodes considered 32+1 or 64+1 (both the cases tested)
3) Reading of the TCP IP data is done with Instrument control toolbox of MATLAB on another computer
3) We tried increasing the input buffer size in the client side
4) The delay in reading is computed using psychtool box(MATLAB)
5) The Laptop connected to BioSemi system is with P4, 2Ghz. And the client is P4, 512RAM, 2Gz.
6) We are using ActiveVIEW Laptop 6.03 version
7) Both the computers are directly connected and isolated from the rest of the network.
Will all the above settings, We have observed a consistent delay in reading the packets.
Apart from the delays, we have observed a flicker in the raster scan-line once as soon as we establish the TCPIP connection, and continues to flicker until the connection is closed. Is it normal?
Can we reduce delays
Thanks in advance,
regards,
Gangadhar, IDIAP Research Institute.