Unable to open COM port on client machine

[rws]

Using VB in VStudio.NET Pro.

 

The app needs to talk through the serial port (COM1).

 

I have added Interop.MSCommlib as a reference (derived from mscomm32.ocx) and have written a class which inherits from MSComm. It works just fine on my XP machine, both in the development environment, and installed.

 

For deployment, I have selected these properties for the mscomm32.ocx file on the target machine: selfReg, application folder, non-permanent. Install and uninstall both work, but the program won't run.

 

I get:

 

System.Runtime.InteropServices.COM Exception 80040112

 

I'm pretty sure it has to do with licensing ActiveX controls, a subject I know nothing about. The Help isn't helpful, since it seems to focus on licensing custom controls, not Microsoft controls.

 

I know I should be using the mscomm32.ocx file registered on the target machine, rather than deploying another copy to the application folder, but I don't know how to do this, and I am especially worried about losing it during an uninstall.

 

Has anyone else run into this problem? Any help would be appreciated. Thanks.

[Derek Stone]

There are plenty of .NET classes available online for accessing the serial port. I'd avoid COM problems and dump the MSComm32 control altogether.

 

COM Exception 80040112 is a licensing problem, just to confirm that statement.

[rws]

Thanks, Derek.

I am about ready to give up on MSComm32.

 

I have found this alternative.

 

Can you suggest any others?

 

Also, thanks for confirming the error message.

[Derek Stone]

I'd use that code example. It's straight from Microsoft, which usually is a good thing.

 

Others can be found on Google:

http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=serial+OR+comm+port+vb.net