Terry,

Go to http://www.sysinternals.com/ntw2k/freeware/portmon.shtml and download PortMon. Run it to capture the port in question prior to starting your app. It may shed some light...

>Need some help! How can I determine if a command is really being sent via an mscomm object to an external device, without having the device connected. I don't know if the problem is the device or the 'sending' of the command.