Sending triggers through parallel port to EEG amplifier

Hardware
,
1

Hi!

I am running my experiment in PTB, while EEG is recording in brain vision recorder.
I am having some difficulties in sending triggers through a parallel port. In previous topics I found this possible code:

ioObj = io64;
status = io64(ioObj);
address = hex2dec(‘E010’);

io64(ioObj,address,value);
WaitSecs(0.01);
io64(ioObj,address,0);

But as soon as I run the experiment MATLAB returns an error in “ioObj=io64” as an unrecognized function or variable. I am new to programming so I’m having some trouble in figuring out what the problem might be.
My stimulation computer is 64-bit with the Windows 10 version, and my MATLAB version is 2018. I’m using the actiChamp amplifier.

Can someone help me find the problem?
Thank you.

Maria

2

MATLAB returns an error in “ioObj=io64” as an unrecognized function or variable.

io64 is not (and never was) part of Psychtoolbox. Apparently it is no longer available or supported by the original source. You might possibly be able to download a copy from the Wayback machine:
https://web.archive.org/web/20210211055927/http://apps.usd.edu/coglab/psyc770/IO64.html

Best,
Andreas

1 Like
3

Hi Andreas,

Thank you for your response. It worked!

Thanks!
Maria

4

Hello,
I am currently encountering an issue with sending a trigger to the parallel port using MATLAB.
I am using the following code:
ioObj = io64;
status = io64(ioObj);
address = hex2dec(‘E010’);
io64(ioObj, address, value);

However, I receive the following error message:
inpoutx64 driver is NOT open

As a result, the trigger is not being sent to the parallel port. I would greatly appreciate any guidance or advice you could provide on resolving this issue.
Thank you for your time and assistance.

5

Hello
I did what is told in this link: Mex-File Utility for Fast MATLAB Port I/O (64-bit)

It seems like it is working, and it is recognizing the function ‘outp’ that I need.
But now the program is not running and it says:

"Error using AssertOpenGL
Problems detected in call to AssertOpenGL;

Error in PsychDefaultSetup (line 58)
AssertOpenGL;

Error in Experimento2TRSe (line 3)
PsychDefaultSetup(2);"

What can I do??

6

You’ll need to provide more details than that, like the full error output, the PTB version you use - only 3.0.22 is supported by now, etc., just as we ask for in the instructions on how to use the forum.

7

Hi Mario, I´m using the PTB version 3-3.0.19.14. I just made a test and it is recognizing the function ‘outp’ that I need. I´m using Windows 10 and Matlab version 2022b and I´m using actiChamp amplifier.
But when I was just running my program to test if it was ok, the program did´nt even open and sent that message above.

8

Hi Fernanda. As stated, PTB 3.0.19 is no longer supported, only the paid version 3.0.22 is at the moment. Please install that and buy a software license for it. If the problem persists, please post the full output and also what you have tried according to the instructions contained in those error messages. I’m on vacation atm., so responses are not guaranteed and may take quite a while if the problem doesn’t resolve itself by installing PTB 3.0.22, but no support will be provided by myself for unpaid versions at all.