I've currently setup a Cedrus StimTracker to send TTL signals from my stimulus presentation computer to a Neuroscan NuAmps EEG amplifier to mark events. The Cedrus Stimtracker has a USB connection, but emulates a serial port connection (for more information, see here: http://cedrus.com/support/stimtracke...ll_usb_win.htm). I've verified the Stimtracker device is working properly by sending signals using RealTerm (similar to Hyperterminal) from the stimulus machine to the EEG recording software. Markers are showing up perfectly. However, I'm having difficulty sending TTL signals from within DirectRT (i.e., the IOtest utility). The problem is that DirectRT seems to require a decimal port address to send the TTL. Since the Cedrus box creates a virtual serial port (COM 3 on my system), there is no hardware port address (there is no resources tab for the port in device manager, per these instructions: http://www.empirisoft.com/support/sh...r-(case-17709). I have tried using port 1000 (which to my knowledge would be the decimal address of COM3), but this doesn't work. I'm wondering if you know of a way to find the appropriate port address for the virtual serial port, or if there is an alternative workaround that will allow me to send TTL triggers using DirectRT. Thank you.
Robert Goodman