Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Supported by

[solved] Sending triggers to Nexus Trigger Interface via serial port

edited May 2013 in OpenSesame


My name is Daniel and I'm currently working on an experiment with our new Nexus-32 eeg. As the title reveals, I'm having some problems with the triggers sent to the Nexus Trigger Interface (NTI) via serial port. Even your tutorial didn't help. I'm very new to OpenSesame so I'm probably doing several things wrong.

My first question is: Are there any differences between sending a trigger via parallel port and sending it via serial port (the answer is probably yes)? Do I have to change my python Code according to this setting?

    from ctypes import windll
    global io
    io = windll.dlportio # requires dlportio.dll !!!
    print 'The parallel port couldnt be opened'


global io
trigger = 1
port = 0x378
    io.DlPortWritePortUchar(port, trigger)
    print 'Failed to send trigger!'

Or do I have to use another .dll?

I'm sure, however, that the hardware is working correctly. I was able to send a trigger via HyperTerminal to the NTI and it worked properly. These are the settings I used in HyperTerminal (sorry for the german language version):



There is one last question ... ;-) I checked the port adress of the serial port with a tool called Bios Reader and it showed me the following adress:


So I guess that I have to use the port 0x3F8 instead of 0x378 in the python code, right?

As you see I'm quite confused and any help is appreciated ;-)

Best wishes,



  • edited 3:53AM

    Hi Daniel,

    My first question is: Are there any differences between sending a trigger via parallel port and sending it via serial port (the answer is probably yes)? Do I have to change my python Code according to this setting?

    Yes, the parallel and serial ports require entirely different approaches. Fortunately, the serial port is actually much easier to access, because it doesn't require the use of any external .dll libraries. You can simply rely on the serial module. You can find some examples here:

    In your case, you might open the serial port with a script like this at the start of the experiment:

    import serial
    exp.serial_port = serial.Serial('COM1') # Can also be COM2, COM3, etc.

    And then send a trigger like this (at some moment during a trial):

    exp.serial_port.write(chr(1)) # Send the byte 1 as a character

    At the end of the experiment, you need to close the connection again (otherwise you may experience trouble running the experiment twice without closing OpenSesame):


    Good luck!


    Buy Me A Coffee

  • edited 3:53AM

    Hi Sebastiaan,

    thanks a lot for your support. It works just fine!

    Best wishes,

  • edited 3:53AM

    now could any one help me i am using vspe

  • edited 3:53AM


    Final warning :-t Please resume with the discussion (one of many) that you have started yourself (here). If you continue to open new discussions and/ or randomly post in old discussions, your account will be suspended.

    Buy Me A Coffee

  • Hi, New user... OpenSesame seems to be a great program. Thanks for sharing! I am trying to get the above in-line-scripting to send signals from OpenSesame to Biopac via a USB TTL Module (Black box toolkit).

    I have tried the inlinescripting posted above. However, I am getting an error message:

    TypeError exception message: unicode strings are not supported, please encode to bytes:""x01

    Could someone advise? Many thanks in advance,


  • Update, solved but other problem arisen.

    I tried changing the unicode to bytes, and it seems to have worked as far as the previous particular error message goes. This is the code for triggering now

    1 exp.trig.write(0x31)

    2 exp.trig.write(0x30)

    However, I am not getting a new error message for the inline script controlling the port. I think it is row 3.

    1 from serial import Serial

    2 exp.trig = Serial('COM3', 115200)

    3 exp.cleanup_functions.append(exp.trigger.close)

    "in _getattr_ raise AttributeError(u´%s not found´ % var) AttributeError: trigger not found.

    Any help would be appreciated, thanks in advance

  • Hi @Gunnar

    The variable is called exp.trig, not exp.trigger.

    As an aside, I suspect that this code is based on something that was written a long time ago, when you needed to attach variables as properties to the exp object in order to be able to access them in all scripts. However, this isn't necessary anymore, and you can just use the global variable trig. It won't make any functional difference, but it will make your code a bit cleaner.

    See also:

    — Sebastiaan

    Buy Me A Coffee

  • Hi,

    thank you @sebastiaan

    Appreciate it, I will try this when back in the lab.

  • Hi again and thanks again @sebastiaan .

    I have tested this now and the error message about exp.trigger disappeared so that part is solved.

    However, I still can't seem to activate the USB TTL Module to send triggers from the experiment. I suspect I am still using the wrong trigger numbers in the inline script , the TTL module is asking for two byte hex values (for instance, line 1 on the module uses dpin 2 and hex 01). How would this work with the exp.trig.write() command? I have tried ("01"), ('01'), (0x31) and (0x01). The ("01") asks to convert from unicode to bytes, the (0x31) doesn't return an error message (but nothing happens in terms of triggering)

    Best regards,


Sign In or Register to comment.

agen judi bola , sportbook, casino, togel, number game, singapore, tangkas, basket, slot, poker, dominoqq, agen bola. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 50.000 ,- bonus cashback hingga 10% , diskon togel hingga 66% bisa bermain di android dan IOS kapanpun dan dimana pun. poker , bandarq , aduq, domino qq , dominobet. Semua permainan bisa dimainkan hanya dengan 1 ID. minimal deposit 10.000 ,- bonus turnover 0.5% dan bonus referral 20%. Bonus - bonus yang dihadirkan bisa terbilang cukup tinggi dan memuaskan, anda hanya perlu memasang pada situs yang memberikan bursa pasaran terbaik yaitu Bola168. Situs penyedia segala jenis permainan poker online kini semakin banyak ditemukan di Internet, salah satunya TahunQQ merupakan situs Agen Judi Domino66 Dan BandarQ Terpercaya yang mampu memberikan banyak provit bagi bettornya. Permainan Yang Di Sediakan Dewi365 Juga sangat banyak Dan menarik dan Peluang untuk memenangkan Taruhan Judi online ini juga sangat mudah . Mainkan Segera Taruhan Sportbook anda bersama Agen Judi Bola Bersama Dewi365 Kemenangan Anda Berapa pun akan Terbayarkan. Tersedia 9 macam permainan seru yang bisa kamu mainkan hanya di dalam 1 ID saja. Permainan seru yang tersedia seperti Poker, Domino QQ Dan juga BandarQ Online. Semuanya tersedia lengkap hanya di ABGQQ. Situs ABGQQ sangat mudah dimenangkan, kamu juga akan mendapatkan mega bonus dan setiap pemain berhak mendapatkan cashback mingguan. ABGQQ juga telah diakui sebagai Bandar Domino Online yang menjamin sistem FAIR PLAY disetiap permainan yang bisa dimainkan dengan deposit minimal hanya Rp.25.000. DEWI365 adalah Bandar Judi Bola Terpercaya & resmi dan terpercaya di indonesia. Situs judi bola ini menyediakan fasilitas bagi anda untuk dapat bermain memainkan permainan judi bola. Didalam situs ini memiliki berbagai permainan taruhan bola terlengkap seperti Sbobet, yang membuat DEWI365 menjadi situs judi bola terbaik dan terpercaya di Indonesia. Tentunya sebagai situs yang bertugas sebagai Bandar Poker Online pastinya akan berusaha untuk menjaga semua informasi dan keamanan yang terdapat di POKERQQ13. Kotakqq adalah situs Judi Poker Online Terpercayayang menyediakan 9 jenis permainan sakong online, dominoqq, domino99, bandarq, bandar ceme, aduq, poker online, bandar poker, balak66, perang baccarat, dan capsa susun. Dengan minimal deposit withdraw 15.000 Anda sudah bisa memainkan semua permaina pkv games di situs kami. Jackpot besar,Win rate tinggi, Fair play, PKV Games