Sending signals to ASL eye tracker

1
Hi,

I need some help with the Mac commands to send a signal to the ASL eye
tracking system to start and stop logging.

I use a G4 Mac / OS 9.2.2 / Matlab 5.2.1 / Latest psychtoolbox. I want
to send the signal through the USB port to the ASL device (leg 15). The
command should notify the ASL when an experiment trial has begun and
when its ended.

Thanks in advance,

Rani Bar-On
http://iipdm.haifa.ac.il