Setting Which TWAIN Specification Version to Use

LEADTOOLS Twain toolkits support both the TWAIN 1.9 and the TWAIN 2.x specifications. By default LEADTOOLS Twain starts TWAIN 2.x. If that fails it will try to start TWAIN 1.9. It is also possible to specify which version to use. To do so, call the TwainSession.SetVersion method and pass “Version1” to use version 1.9, and “Version2” to use version 2.x. More information about the different specifications follows.

TWAIN 1.9 specification - Version 1.9 uses the twain_32.dll, located in the c:\Windows directory. Use this DLL in 32-bit applications. TWAIN 2.x specification - Version 2.x supports both 32-bit and 64-bit operating systems and uses the twaindsm.dll. On machines running 32-bit operating systems, the DLL is in the Windows\System32 directory. On machines running 64-bit operating systems, the 32-bit version of this DLL is in the Windows\SysWOW64 directory, while the 64-bit version of this DLL is in the Windows\System32 directory. The 64-bit version is a “true” 64-bit DLL rather than a 32-bit DLL modified to run on a 64-bit operating system.