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

edited May 2013 in OpenSesame

Hi!

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?

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

and

global io
trigger = 1
port = 0x378
try:
    io.DlPortWritePortUchar(port, trigger)
except:
    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):

image

image

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:

image

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,

Daniel

Comments

  • edited 12:20AM

    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):

    exp.serial_port.close()
    

    Good luck!

    Cheers,
    Sebastiaan

  • edited 12:20AM

    Hi Sebastiaan,

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

    Best wishes,
    Daniel

  • edited 12:20AM

    now could any one help me i am using vspe

  • edited 12:20AM

    @meldiwiny

    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.

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