You need a program you develop to emulate the null-modem connection with other communication applications and control the data exchange fully.
Virtual Serial Port ActiveX Control allows creating additional virtual serial ports right from your own application. You gain full control over the data that application exchanges with the port. For your utter convenience Virtual COM port ActiveX also features integration samples for Delphi, C++ Builder 6.0, Microsoft VC++ 6.0, Microsoft Visual Basic 6.0, Visual Basic.Net, Visual Studio C# and Visual C.Net.
With Virtual Serial Port ActiveX Control your application is able to create, remove, and fully control virtual COM ports. It makes possible to intercept data sent to virtual serial port and send any custom data in response.
Virtual ports fully emulate the real ones, including connection line break, baud rate, signal lines, pinout (default or custom), etc. Full emulation of baud rate is also available with Virtual Serial Port ActiveX Control.
Virtual Serial Port ActiveX Control offers convenient set of events to control the changes of virtual serial port state.