COM Port Sample

This sample demonstrates how to control a communications port.

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    • On the Help menu, click Samples.

      The Readme displays information about samples.

    • Visit the Visual Studio 2008 Samples Web site. The most recent versions of samples are available there.

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Security noteSecurity Note:

This sample code is intended to illustrate a concept, and it shows only the code that is relevant to that concept. It may not meet the security requirements for a specific environment, and it should not be used exactly as shown. We recommend that you add security and error-handling code to make your projects more secure and robust. Microsoft provides this sample code "AS IS" with no warranties.

To run this sample

  • Press F5.


This application requires a modem installed on one of the COM ports.


  • How to determine which COM ports are available.

  • How to use a COM port to communicate with a modem.

  • How to use Win32 API calls to control communication with the COM port.

See Also


How to: Dial Modems Attached to Serial Ports in Visual Basic

Other Resources

Accessing the Computer's Ports