Open the Source

Note:  By default, DTWAIN automatically opens the Source once the Source has been selected, however there are cases where the Source must be opened explicitly by the application.  See DTWAIN_OpenSource for more information on when the application must call DTWAIN_OpenSource explicitly.

After selecting the Source, the application should open the Source using DTWAIN_OpenSource.  Opening the Source transitions TWAIN from State3 to State 4.