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Send TTL via serial port to external computer (case 31130)

  1. #1

    Send TTL via serial port to external computer (case 31130)

    Hi all,

    I am running DirectRT on a newer Dell machine with a serial port in an EEG experiment (run with EGI's Netstation software). I am looking to send TTLs to the Netstation software. I have conducted the IO test utility and it seems that DirectRT is sending 0-255 values to the serial port.

    Online in and these forums, I am unclear about whether I need a comport file. I have tried running an experiment without one, and it does not seem that TTLs are reaching the Netstation software. When I run it with the comport file, it seems that Netstation registers a 126 value when the program initializes and finishes, but then registers a 46 at periodic points in the experiment (and it seems that sometimes these are registered at the point in the trial I have requested a TTL but other times it misses them). Note that I am only trying to send values 1-6.

    Note that the port that works in the IO utilities is 1023 and I have determined that the other options (Rate, parity etc) match up to the parameters in the port. Also note that the serial cable is attached not to the Netstation computer directly, but to the EEG amp (which is then connected to the computer).

    I have been in touch with EGI as well, so I am trying to determine on what side of this serial port the issue is arising (is it in what DirectRT is sending or is it how Netstation is registering what is being sent). The other thing that I am unclear on is that, at least with media lab, a comport file is necessary only for receiving TTLs, whereas the manual for DirectRT seems to suggest it is for sending and receiving. Is this correct?

    Any thoughts/tips you might have would be greatly appreciated as I try to troubleshoot this.

    Thank you!

    Heath

    ### comport file

    comPort, baudRate, parity, dataBit, stopBit
    1023,19200,n,8,1
    input code (1-255), response value (1-12)
    1,1
    2,2
    3,3
    4,4
    5,5
    6,6

  2. #2
    What version of DirectRT are you running?

  3. #3
    Thanks for the reply!

    I am running v2016.

    Heath

  4. #4
    Hello again!

    I just wanted to follow up on this. I only have a serial port on the machine that is running DirectRT(v2016). Could this be part of the problem?

    Heath

    What version of DirectRT are you running?

  5. #5
    Have you tried hooking the computer with DirectRT directly to the computer with Netstation to see what happens with the signals?

    Please also send me a copy of the .csv file you are using with DirectRT to send the signals.