Acquisition server and LSL with 2 different PC

Obtaining data from various hardware devices
Post Reply
Mike_qp
Posts: 5
Joined: Sat Apr 03, 2021 1:38 pm

Acquisition server and LSL with 2 different PC

Post by Mike_qp »

Hi everyone,

I'm new here and with OV, i'm trying to set up P300 experiments with OV for real time BCI.

I'm using a Brain Product EEG device and Psychopy to run a classical oddball task.
Everything is synchronized via LabStreamingLayer (LSL).
I have one computer on which I'm running Psychopy, and the other one the EEG. These 2 PCs are networked by ethernet connection and my LSL .xdf is working perfectly at the end of an experiment.

My problem :
When I try to do real time P300 visualization with OpenVibe, by connecting the LSL driver to the Acquisition Server, i'm not able to see the psychopy stream for markers.
- 1) psychopy markers are int32 data format as required by OV.
- 2) it seems That the problem comes from the fact That i'm using 2 different PCs. When I try to run everything on one PC it is working. But my experiments require two different machines.
- 3) if I run OV on the "EEG" computer, i can't get Psychopy markers. If i run OV on the" Psychopy" computer, i can't receive the eeg stream via LSL. And as i mentionned before, LSL is working fine without OV with my set up.

Is there a way to fix This? Maybe it is linked someway to a port number or something ?

Thanks for tour help

Cheers

Thibaut
Posts: 227
Joined: Wed Oct 31, 2018 9:14 am

Re: Acquisition server and LSL with 2 different PC

Post by Thibaut »

Hi,
My First question is why 2 computer ?
Basically if you need 2 computer because of computes power. One of them can have all acquisition (EEG and Marker) and the second the process.
If it's impossible, To minimize ethernet communication your configuration with EEG and process in one computer and the second with marker only it's better (with p300 the real real time is important. And complex communication can invalidate your protocol.)
For LSL communication in OV, normally if you are in same network it works actually.
Thibaut

Mike_qp
Posts: 5
Joined: Sat Apr 03, 2021 1:38 pm

Re: Acquisition server and LSL with 2 different PC

Post by Mike_qp »

Thanks for your reply !

First, I need 2 pc so that subjects can realize the cognitive task (say Oddball) while experimenters may run real time analysis on another computer without disturbing the cognitive task.

As i said, my 2 computer are linked by a simple ethernet connection.

LSL communication in OV doesn't allow me to get for instance an EEG stream if it comes from a different computer (OV consol says there is no EEG data), although LSL recordings are working perfectly well outside OV. Edit : to precise further, i can see the name of the EEG stream in the driver but it seems that the stream is empty and OV rise an error.

Thanks for your help

Thomas
Posts: 68
Joined: Wed Mar 04, 2020 3:38 pm

Re: Acquisition server and LSL with 2 different PC

Post by Thomas »

Hi,

What OSs are the laptops running ? Are there two windows machine ?

Have you checked your firewall settings ?

I will do some testing on it soon.

Cheers,
Thomas

Mike_qp
Posts: 5
Joined: Sat Apr 03, 2021 1:38 pm

Re: Acquisition server and LSL with 2 different PC

Post by Mike_qp »

Dear Thomas,

I'm running 2 Windows 10 PCs.

For the firewall, all I can say is that lsl communication between the 2 pc is working fine both for writing or reading stream on one or the other.

Thanks for your help !

Post Reply