[FieldTrip] Brainvision recorder RDA

Robert Oostenveld r.oostenveld at donders.ru.nl
Wed Nov 16 16:57:38 CET 2011

Dear Casper,

The message did not sound familiar so I whad to go into the code to look it up. In fieldtrip/realtime/acquisition/brainamp/rda2ft.c there is this section

        switch(header.nType) {
            case RDA_START_MSG:
                handleStartPacket(ftSocket, header.nSize, buf);
            case RDA_INT_MSG:
            case RDA_FLOAT_MSG:
                handleDataPacket(ftSocket, header.nSize, buf);
            case RDA_STOP_MSG:
                printf("\nRemote Data Acquisition stopped\n\n");
                fprintf(stderr, "Unrecognized packet type (%i), has size %i - exiting\n", header.nType, header.nSize);
                keepRunning = 0;

where the last case pertains to your message. So shat seens to happen is that rda2ft receives a packet from Recorder and subsequently has to interpret its content. The expected values are

#define RDA_START_MSG   1
#define RDA_INT_MSG     2
#define RDA_STOP_MSG    3
#define RDA_FLOAT_MSG   4

but apparently your Recorder sends a different package of type "1000". I don't know why that happens. Perhaps it is a different version of the software. My first suggested solution would be to change 
                keepRunning = 0;
                keepRunning = 1;
and then hope that dropping this particular packet does not cause problems later. Better would be to try to identify what the packet contains and actually deal with it, but I would not know where to get accessible documentation for this.

I hope that you are able to make the change and recompile this yourself. If not, please file a request for the code enhancement at http://bugzilla.fcdonders.nl (create account, file new bug, change status in "enhancement") and one of us will look at it.

best regards,

On 16 Nov 2011, at 12:21, Casper van Heck wrote:

> Dear all,
> I'm trying to connect to Brainvision recorder using the built-in RDA system and the rda2ft-files. I've got two computers; one with recorder and the rda2ft-files, and one with the rest of fieldtrip which should connect to the fieldtrip buffer. The goal is to get the secondary computer to show the subject its performance (for example; the rms of a single channel) within the task constraints.
> When running rda2ft.exe (with the parameters localhost and 51244) it does seem to connect; it shows the list of channels (all channels), their resolution, and their names, and some other assorted stuff. However, it then says:
> "Unrecognized packet type (10000), has size 24 - exiting"
> What does this mean, and how can I fix it? I've tried messing with the settings of recorder, but nothing I do seems to make a difference.
> Sincerely,
> Casper van Heck
> _______________________________________________
> fieldtrip mailing list
> fieldtrip at donders.ru.nl
> http://mailman.science.ru.nl/mailman/listinfo/fieldtrip

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