In order to add Tango DLL functionality to your Visual C++ project, you have to follow this steps: -------------------------------------------------------------------------------------------------- 1) Copy "Tango.cpp", "Tango.h" and "Tango.dll" into your project's folder 2) In your "[projectname]Dlg.h", please insert: a) #include "Tango.h" b) under "public:" or "protected:" CTango *pTango 3) In your "[projectname]Dlg.cpp" under "OnInitDialog()", please insert: pTango = new CTango(); 4) When closing your dialog, please don't forget to do some clean up in "OnClose()": pTango->Disconnect(); delete pTango; 5) Now you're ready to use the DLL, simply call any DLL function like pTango->ConnectSimple(1,"COM1",57600,false);