FtVspcCreateTwinPortByNum Function

Creates virtual serial port twin.

BOOL FtVspcCreateTwinPortByNum(
	UINT unPortNo,
	LPCTSTR lpszRealPortAlias 



[in] COM port number (e.g. 5 means COM5).


[in] Alias name for existing COM port. You still will be able to open existing COM port using this alias name. The string is an MS-DOS path (e.g. PORT1, COM100).

Return Value

If the function succeeds, the return value is TRUE. Otherwise, use FtVspcGetLastError to get the error code (FtVspc_ErrorCode).


ftvspcErrorFailed 1 The operation has not been completed.
ftvspcErrorInvalidParameter 2 Invalid parameter.
ftvspcErrorPortAlreadyExists 100 This port already exists.


Port twin is an overlapped virtual serial port created over the physical serial port and existent only when the physical port exists.

Once created, port twin is available for enumeration by FtVspcEnumVirtual function but does not exist in the system (does not visible in the device manager). It appears in the system only if corresponding physical port appears. When physical port is removed from the system, port twin is removed too.

Port twin can be permanent. In this case it will be available for enumeration by FtVspcEnumVirtual function at each system startup and will exist in the system if corresponding physical port exists.

See Also

FtVspcCreateTwinPort, FtVspcCreateTwinPortEx, FtVspcEnumVirtual, FtVspcGetPortType