Unable to detect trigger in a Siemens scanner

Builder
1

Hi everyone,

We are trying to set up an fMRI experiment with Psychopy in a Siemens 3T scanner. The trigger box is connected via parallel port, and it seems to be working, but for some reason Psychopy won’t recognise it.

We set up a code routine to wait for the scanner before starting the experiment:

from psychopy import parallel

port = parallel.ParallelPort(address = 0x6EFC)

We also tried to add the parallel out component without success.

Any suggestions would be highly appreciated on how to proceed.

Many thanks!

But it never starts the experiment.

OS: Win 11 Pro
PsychoPy version: 2024.2.4

2

Hi-

Which trigger box do you have? We’ve generally found it more reliable to use the trigger as a keyboard emulation.

But if you’re really set on reading from the parallel port you might find these threads helpful:

  1. Reading from parallel port
  2. Reading parallel port pin (for acquiring response from response pad) for MEG experiment - #12 by jtseng

I believe you’ll need a line of code to read data from the port and do something with it.

-PM