Thread: matlab parallel port interfacing?

hi. I want to know how to interface matlab with parallel port. I should probably mention that i'm using a laptop which does not have a parallel port so i'm using USB to parallel port converter cable. This is the code i used

parport = digitalio('parallel','LPT1');
line = addline(parport,0:3,'out')
putvalue(parport.Pin2,0)

i'm actually creating a GUI based traffic signal which needs to be interfaced by parallel port. I tried and checked the GUI using simple text boxes to see it's working perfectly but the interfacing isn't happening and it keeps giving errors.
Thanks in advance