Hi, A VB application can activate DTR or RTS. Does anybody knows how can be measured the delay between DTR or RTS enabling and the real 1 or 0 in the data line? Regards, Dennis Crawley www.geocities.com/proyectosenpic -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist