about tcp tagging with g.Nautilus

Obtaining data from various hardware devices
Post Reply
jeonghun
Posts: 4
Joined: Mon Nov 14, 2016 2:12 am

about tcp tagging with g.Nautilus

Post by jeonghun »

I have tested tcp tagging with g.Nautilus, but there exists severe jitterring which makes ERP analysis difficult. When I tested the tagging program with Generic oscillator,there were no problems. Are there anyone who experienced this problem? and who knows how to solve this problem?

Thanks.

jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: about tcp tagging with g.Nautilus

Post by jtlindgren »

Hi Jeonghun,

we don't have gNautilus here at the lab, so we cannot test the driver. Questions,

1) Have you tried contacting gtec about the problem? They contributed the driver.
2) How did you test the tcp tagging? Which component sent the tags?
3) Did you use timestamps for the sent tags or tag them as immediate?

Regarding Q1, the TCP Tagging doesn't happen inside the driver, but it is
possible that there is some interplay between how the driver works (for
example how long it takes to deliver buffers and does that time fluctuate)
and how the tagging works.


Thanks,
Jussi

jeonghun
Posts: 4
Joined: Mon Nov 14, 2016 2:12 am

Re: about tcp tagging with g.Nautilus

Post by jeonghun »

Hi Jussi,

Thank you for your kind reply.
I have also connected to the g.tec members, and I got the simple answer that the driver is extremely recent, so the problem would be occurred.

But, I have one more question regarding the tcp tagging with timestamp.
I actually tried to tag as immediate and it seems that the the stimulation tag would be delayed to the server.
Is it possible to fix if I tag with timestamp?
Then, How could I implement it in c# code?

Regards
Jeonghun Ku

jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: about tcp tagging with g.Nautilus

Post by jtlindgren »

The interpretation of the immediate tagging is that the server should pad the marker to the signal as soon as the marker is received -- the tag is timestamped with the current time on arrival at the server. Are you having all the components on the same computer? If not, there might be additional issues from clock synchronization.

From the page

http://openvibe.inria.fr/tcp-tagging/

you can find pointers to C++, Python and Java implementations of the tcp tagging clients, likely a C# tagger would be very close to these.


Hope this helps,
Jussi

jeonghun
Posts: 4
Joined: Mon Nov 14, 2016 2:12 am

Re: about tcp tagging with g.Nautilus

Post by jeonghun »

Yes, I have all the components on the same computer. But, the delays and jittering were occurred.
Then, the problem seems coming from the nautilus's driver?
Or, If i tagged with time stamp, Could it be corrected though the components are on the same computer.

I did implement my code from the site you mentioned in C#. but, I could not find out how timestamp could be applied.
Could you get me the sample C# code to tag with timestamps?

Thanks
Jeonghun Ku

Post Reply