EEG, MAC parallel port


I’m doing an task and I want my computer to send triggers to my eeg computer.

I have a mac air. I plugged a usb-parallel port. It seems like my computer does not recognize my parallel port

I get this error:

if t >= 0.0 and p_port.status == NOT_STARTED:
AttributeError: 'ParallelPort' object has no attribute 'status'

I dont know about the port address either.

Someone can help please ?


This is probably not helpful to you, but in my experience parallel port converters are difficult to get to work for these applications (in fact, I never got one to work how I wanted) . So far I’ve either built my own hardware for TTL signals, or used a “real” lpt port…

Did you install the drivers? Do you have any other way to test the port on the machine?

I talked to mac support and they told me I don’t need any drivers…It should work well he said.

We dont understand why psychopy don’t see it.

Was psychopy built to work in mac with the parallel port ?


I have used psychopy with USB parallel port adapters on a mac, but they probably all differ. Since buying a labjack I haven’t used parallel ports though - the labjack offers the same functionality and more

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I’ll order a USB/parallel adapter to see if the code generally works. But let’s also try and find out about your system.

Can you tell us what the device is (brand and model if possible)?
Possibly PsychoPy isn’t finding the right address for it. You can find this out in the mac terminal window by entering these command before and after inserting the usb cable and seeing which addresses change (when you plug in the usb cable a new address should appear):

ls /dev/tty*
ls /dev/cu*

Thanks for your help. Unfortunately I’m not at my lab right now, I will get the answer about the cable monday.
I will give you feedback then.

Hi again

We are using a Macbook air, mac OS Sierra, version 10.12.5.
We bought a Redlink USB male to DB25 female cable, which is supposed to be compatible with MacOS/Linux.

I looked at the list of tty* and cu* files before and after inserting the USB-parallel port cable, but it didn’t show any new file.

Any additional insight would be greatly appreciated. Does it work properly on your side? Thank you very much for your help.

Hi there!

Im getting a similar error as this : "AttributeError: ‘ParallelPort’ object has no attribute ‘status’ " when I try to run my builder-based MEG experiment on my Mac Mojave 10.14.

Were you able to solve this issue?

@Gol what version of PsychoPy are you using and were there any other lines in the error message?

Hi Jon,

Im using the most recent standalone Psychopy3.

The only error message is the following:
if t >= 0.0 and p_port.status == NOT_STARTED:
AttributeError: ‘ParallelPort’ object has no attribute ‘status’

Thanks for the help!

I think that is because the attribute status is missing in the dummy constructor for parallel.ParallelPort on Mac.
If you go into the source code, there is no self.status = None as there should be.

However, I think even if you add the status attribute, the ParallelPort object still won’t do anything. I think it won’t throw an error but it won’t send triggers either because it is just a placeholder for Mac users. I might be mistaken though.

I was struggling with this for a while, but this works for me:

1-Check the correct port in mi Mac (fall 2020 M1 chip) in the terminal as Jon said.
2-Run an example script as a SERIAL port, not as parallel. For this, you need to use a code object rather than a parallel object from the builder.

Hope it helps.

@Sebastian_Espinoza Hello, can you share which USB-parallel adaptor you used?
Also, didn’t you experience voltage issue? (as far as I know, some serial device is over voltage issue when directly connect to the most biosignal amplifiers (i.e. Biopac)).

I’m using the biosemi USB trigger adapter (BioSemi EEG ECG EMG BSPM NEURO amplifiers systems) which avoids the voltage issue.