As far as I can recall - yes. I used the DB25 port on the side panel of MP150 to connect with the computer running psychopy. Then on the data acquisition computer, I set several digital channels in AcqKnowledge (when creating template files) to pick up markers (one channel for each type of marker). No coding is needed on Biopac’s end as far as I can recall.
Here are some information about the DB25 port and digital channels (page 7-8) https://www.biopac.com/wp-content/uploads/MP150-Systems.pdf
PS: Unlike U12, U3 has a DB15 port, so we had to wire digital lines by ourselves.
(see also EEG Triggers via Labjack: How to do the Parallel Port DB25 connection)