Hi all, currently i am trying to use a java app to read from my usb to serial port on my PC. i research and found that Windows COM ports are not directly supported by Sun anymore. thus there is another package called rxtx. http://www.captain.at/howto-java-ser...-comm-rxtx.php i tried the above link with my app, however it return me portId=null; from the link belowNew Windows Java Serial Com Port driver with proper handling of Timeouts) http://www.engidea.com/blog/informat...m/winjcom.html it stated that the usb to serial maybe a problem when using the rxtx package, and this winjcom maybe a good substitute. however, is there any expertises can share their advice on how to use this winjcom. thanks in advance. any help will be greatly appreaciated.