Unable to Open COM port


I am having a problem with the comport. I have Etherlite realport on a test rack and used for an Ethernet connected power supply. I am writing a program in VB .Net and create a basic comport opening routine that I use for other devices on other comports. I have it set for 11 and I get “unabe to open COM11”. Now when I use Hyperterminal, I am able to open and communicate with the device. Any ideas?

This is more than likely a limitation with your application, if you can open com 11 and it works fine with Hyperterminal, but not with the application you’re trying to use with the Etherlite.

This may also be a limitation of the OS that Realport is being installed on, so what Operating System are you using?

There may be 2 issues.
If you cannot open any port above com 9, then please see the information at this link:
You may also run into a VB issue with the limit of com ports VB will support. In this case, you will need third party programing extensions. One such provider is at this link:

Thanks for the responses.

michaelt - We run Windows2000

async, thanks for the links. I will give the first one a try and then look into the commstudio. And if I get it to work I will post what happened for others with a similar problem.

Got it to work. The solution. I had an older version of RS232.vb, which is from MS themselves. Someone has redid it and called it CRs232.VB. The first Link that async put up led me in the right direction. I tried just the .com# and didn’t work. When I found the better version of CRs232.vb this is what he had. \.\COM#

For VB .NET 2005, it comes with a serial port connection in Framework 2.0.

Unfortnutely I have 2003 and use framework 1.1.