EEG Triggers from a Mac

[James]

Hi There,

I am trying to set up EEG triggers to be sent from a Mac laptop. Given how difficult this has been, I'm either assuming that no one else has ever done this, or I am missing something REALLY obvious. So, if there is a general solution to this problem, please let me know.

More specifically, the best solution we have found so far is a u6 device from labjack.com, as this is suppose to have low latency.

However, this device doesn't simply have a parallel port, it has multiple single line (screw terminals?) output inputs. Though, it does have a db37 and 15 connection with specific pinouts.

The Labjack web support told me :
"the Biosemi thing is or does, but the link does mention that it has 10k pull-ups. I suggest you take a digital I/O from the U3/U6 and try it. I would try EIO0, so connect EIO0 to one of the trigger inputs. Use the test panel in LJControlPanel (on Windows) to change the state of EIO0 and see if it causes the desired result on your device."

I'm wondering if this is going to be safe for the biosemi usb box? As I am reading it, I'm supposed to connect a wire from one of the EIO's on the labjack to one of the DB37 inputs on the USB device.

Thanks,
~James

[Coen]

The LabJack has standard 0/5 V digital outputs. Connecting these to the trigger inputs on the USB-receiver should work fine. There is no danger of damaging anything.

Make sure that besides the trigger lines, you also make a ground connection between LabJack and USB-receiver (Ground terminal of LabJack to pin 37 of the trigger port). So, for the test you should connect at least 2 wires: EIO0 --> Pin 1 and Ground --> Pin 37.

Best regards, Coen (BioSemi)