Are you using direct API calls in real-world solution to communicate with COM port ?

>When the port is open you must call ReadFile & WriteFile for read and write data the in COM port.
>
>---------------------------------------
>Declare Long ReadFile in "kernel32" Long hFile , STRING @lpBuffer, Long nNumberOfBytesToRead, Long @lpNumberOfBytesRead, long lpOverlapped
>
>LOCAL hPort,lpNumberOfBytesRead, lpBuffer
>lpNumberOfBytesRead = 50
>lpBuffer = SPACE(50)
>hPort = CreateFile (lcPort, GENERIC_READ, 0,0,;
> OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0)
>
>ReadFile( hPort, @lpBuffer, 50, @lpNumberOfBytesRead, 0 )
>
>IDEM for WriteFile function.