>>Uisng MScomm activex control I can control up to 16 ports. How can I control more then that? The control simply does not accept anything greater then 16. > >In order to access more than 16 ports you've to use 3rd party controls. For example, http://www.jspayne.com/io/home.html or http://www.eltima.com/download/serial-activex. They both have a demo version. I am trying http://www.jspayne.com/io/home.html but can't get it work. Scan from a scanner is not complete sometimes. Any idea?