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Bug 1172 - No events for BrainAmp acquisition

Reported 2011-11-21 09:31:00 +0100
Modified 2012-06-20 15:03:25 +0200
Product: FieldTrip
Component: realtime
Version: unspecified
Hardware: All
Operating System: All
Importance: P2 critical
Assigned to: Boris Reuderink
Depends on:
See also:

Boris Reuderink - 2011-11-21 09:31:22 +0100

I am using Fieldtrip for realtime P300 classification. i am facing one problem that i am unable to read Events (stimulus markers from Vision recorder) my flashing program is in Visual c, that communicates with vision recorder and markers are displayed correctly in VisionRec. while reading from buffer i get data correctly but it doesn't gives me events. the command event = read_event(cfg.dataset, 'minsample', prevSample+1); gives me an empty vector. I am using FT_REALTIME_BRAINAMPPROXY to read from Vision recorder. with default setting i.e cfg.port=51244; = 'buffer://localhost:1972' = 'buffer://localhost:1972' after that if i use ft_realtime_signalviewer it displays data correctly but it shows no event.

Boris Reuderink - 2011-11-21 09:36:18 +0100

Dear Abdullah Khalid, Could you provide some extra info needed for reproduction of this bug: - What platform(s) do you run the acquistion on? - Which version of FieldTrip do you use? - What version of Matlab do you use? - Could you list specifics of you amplifier? Further, could you describe a series of minimal steps to reproduce your problem? For example 1) start this program on this computer, 2) start start attached script on this computer. Best regards, Boris Reuderink

Abdullah khalid - 2011-11-21 11:16:00 +0100

Created attachment 189 Flashing program that gives markers to Vision recorder

Abdullah khalid - 2011-11-21 11:30:38 +0100

(In reply to comment #1) - What platform(s) do you run the acquistion on? - Which version of FieldTrip do you use? - What version of Matlab do you use? --> Using Windows XP, service pack 3, 32-bit --> Fieldtrip-20111004 --> MATLAb 7.11(R2010b) - Could you list specifics of you amplifier? I am using brain vision's BRAINAMP MR amplifier with brain vision recorder software. Steps to reproduce problem 1) Start brainVision recorder and P300.exe(flashing program that will give markers to vision recorder) 2) use this code to write data to buffer cfg=[];'EEG'; cfg.port=51244;'all';'buffer://localhost:1972';'buffer://localhost:1972'; ft_realtime_brainampproxy(cfg) 3) Open another Matlab instance to read data from buffer and plot it using this code cfg=[]; cfg.blocksize=1; cfg.readevent='yes'; cfg.dataset='buffer://localhost:1972'; cfg.eventfile='buffer://localhost:1972'; ft_realtime_signalviewer(cfg) you will notice that ft_realtime_signalviewer() works fine if there are no markers(events). but when there are Events, it fails to read them.

Boris Reuderink - 2011-11-28 15:43:35 +0100

The content of attachment 189 has been deleted by Boris Reuderink <> who provided the following reason: We do not debug with executables from unknown source. Please provide source if needed. The token used to delete this attachment was generated at 2011-11-28 15:42:52 CET.

Boris Reuderink - 2011-11-28 15:58:33 +0100

Dear Abdulla Khalid, Thank you for this clear explanation. Bug 1164 seems related to your problem, and we are working hard to resolve this issue. You sent a stimulation program (P300.exe). Unfortunately, we cannot debug with executables that are not included with FieldTrip. Would you be so kind to record the network stream that is created by BrainVision Recorder during your experiment? We could then replay it locally to simulate your issue. You can record such a stream with the tool "netcat". On a linux/unix computer, you can use a command like: $ netcat 51244 > bug1182-tcpdump.dat where is the ip address of the computer that runs BrainVision Recorder. A version of netcat is available for Windows at --- note that your virus scanner might complain that it is a hacking tool since it can be used to setup a server as well. If this is unclear, please don't hesitate to ask for help. Best regards, Boris Reuderink </p>

Boris Reuderink - 2011-11-28 16:01:17 +0100

(In reply to comment #5) The netcat command looks garbled, and refers to an unrelated bug. It should be: $ netcat IPADDRESS 51244 > bug1172-tcpdump.dat where IPADDRESS is the ip address of the computer running BrainVision Recorder.

Boris Reuderink - 2012-01-17 12:15:48 +0100

Changed status to RESOLVED:INVALID, since no further communication was received.

Boris Reuderink - 2012-06-20 15:03:25 +0200

Changed my resolved bugs to closed.