VB3 Program Example for COM Port Support in Visual Basic

 Last reviewed: September 17, 1997
Article ID: Q75856
1.00 2.00 3.00 WINDOWS kbprg kbfile

The information in this article applies to:

- Microsoft Visual Basic programming system for Windows, 

  versions 1.0, 2.0, and 3.0

SUMMARY

A sample program (VBCOMDEM) is available to show you how a Visual Basic program can use Windows API functions for serial port communications. This program may not be necessary in Visual Basic versions 2.0 and 3.0 for Windows because COM support is already built into the Communications Control, which comes with the Professional Edition. 

You can find VBCOMDEM.EXE (size: 28549 bytes) 
                         , a self-extracting file, on these services:
  • Microsoft's World Wide Web site on the Internet 

          On the www.microsoft.com home page, click the Support icon
      Click Knowledge Base, and select the product

          Enter kbfile VBCOMDEM.EXE (size: 28549 bytes) 
                               , and click GO!
      Open the article, and click the button to download the file


  • Internet (anonymous FTP)

          ftp ftp.microsoft.com
      Change to the Softlib/Mslfiles folder
      Get VBCOMDEM.EXE (size: 28549 bytes) 

    

  • The Microsoft Network

          On the Edit menu, click Go To, and then click Other Location
      Type "mssupport" (without the quotation marks)
      Double-click the MS Software Library icon
      Find the appropriate product area
      Locate and Download VBCOMDEM.EXE

    

  • Microsoft Download Service (MSDL)

          Dial (206) 936-6735 to connect to MSDL
      Download VBCOMDEM.EXE (size: 28549 bytes) 

    
For additional information about downloading, please see the following
article in the Microsoft Knowledge Base:

    

       ARTICLE-ID: Q119591
   TITLE     : How to Obtain Microsoft Support Files from Online Services


    When you run VBCOMDEM.EXE, you will have the following four files:

    

       SIMPCOMM.EXE, SIMPCOMM.FRM, SIMPCOMM.GLB, SIMPCOMM.MAK


    MORE INFORMATION
    
 

    
In the Visual Basic environment (VB.EXE), you can load the files in
this sample program by choosing Open Project from the File menu and
selecting the SIMPCOMM.MAK file.

    
You can also run SIMPCOMM.EXE in Windows as a separate program that
requires the Visual Basic run-time file VBRUN100.DLL.

    
This sample program is only a starting point. It does not use all of the
serial communications API functions available through Windows. This simple
example uses Windows API Comm functions, such as OpenComm, CloseComm,
ReadComm, and WriteComm. You are free to modify and extend the program to
suit your specific needs.

    
The SIMPCOMM program has no error trapping, and makes no allowances for
noisy communication lines or handshaking errors. Should an error occur,
Windows will suspend all reading from the communications port until
you clear the error by calling the Windows API function GetCommError.

    
To modify or understand this program example, you must have a reference
manual for the Windows API routines.

    

    REFERENCES
    
 

    
"Microsoft Windows Programmer's Reference," Microsoft Press, 1990
Microsoft Windows 3.0 Software Development Kit

    

	
	
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Additional reference words: 1.00 2.00 3.00 COM1 COM2 asynchronous softlib
    
KBCategory: kbprg kbfile
    
KBSubcategory: PrgCtrlsStd
    
Keywords          : PrgCtrlsStd kbfile kbprg
    
Version           : 1.00 2.00 3.00
    
Platform          : WINDOWS
    

    
    

    

    
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	Last reviewed:  September 17, 1997
	
    
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