Psychopy sending event code to biopac via parallel port

OS (e.g. Win10):
PsychoPy version : v2021.1.2
Standard Standalone:
What are you trying to achieve?:
We want to send a specific event code to biopac via parallel port. We have found the address for our parallel port and set it in the parallel component, as shown below:
This is how we set the condition to start and stop sending the event code to biopac:

What did you try to make it work?:
Using this set up, there is no error message. However, we did not see any change in the biopac portal. What is mystery to us is that the even though we zero out the event code channels using code:
p_port.setData(int(0)) the event channels stayed at 5v, as shown below:

And no change of the the event channel signals ever.

Do any body can help me with figuring out whether the we did not something wrong with sending the event code or it is the biopac event channel that we need to reset to zero? I am very lost in this process.

Thanks in advance!

Hi There,

Please can you show the data tab of your component? what trigger values are you using?

I haven’t communicated with biopac via parallel port before but have via serial port - sharing incase helpful alternative:

Begin exp:

import serial
ser = serial.Serial('COM3', 115200, timeout=1)

Begin routine



Hi Becca,
I’m trying to communicate with biopac via serial port as you’ve mentioned here. I posted a question with some details here.

Would you be able to explain a bit about how the code that you posted here works (either as reply to this thread or the other)? One issue that I encountered is that I only seem to be able to send bytes without error. Thanks!