need help triggering BrainVision EEG with LPT port using LabVIEW

[BradF]

Hi all,

I hope someone can help me figure out this issue, which if my experience is any indication, is likely a simple solution that my novice LabVIEW and non-existent engineering skills have caused. Basically, I can't seem to figure out how to send a digital trigger (either directly through the LPT port or indirectly through an NI device) to our BrainVision EEG system adapter. We have some software (i.e., Presentation) that can send digital triggers through the LPT port to the adapter with no problem, but I have designed our experiment in LabVIEW and need a way to trigger the USB2 adapter using a 25pin connector plugged into our LPT port (just like Presentation uses). We weren't able to use the VISA vi's (likely do to my unfamiliarity with those) to trigger the port itself, so we bought an adapter piece (shown in green) to try and send a signal through one of the pins (shown in the second picture). 

Perhaps I am overthinking it or just lack the knowledge to engineer an appropriate solution. Does anyone have experience with sending digital triggers through the LPT port using BrainVision or a similar system? My only experience has been using the DAQmx vi's to send digital triggers within a stream of data output (i.e., raw data --> 5V signal --> raw data), but BrainVision appears to want a single on-off signal to be sent that show up below the EEG channels as a trigger....and this is out of my wheel house. 

Thanks in advance for any help you can offer!!

[Claire.C · Accepted solution]

Hey Brad,

I can't speak to the requirements of the specific hardware you are communicating with, but if all you need to do is send a digital signal to a particular pin for a trigger, you can do this using the DAQmx functions for digital I/O.

In LabVIEW, you can find examples for how to use the digital output in Help>>Find Examples... under Hardware Input/Output>>DAQmx>>Digital Output 

Hope this helps!