Home › Forums › TWAIN Classic › Question-Data source is not listed on some app.
- This topic has 2 replies, 3 voices, and was last updated 9 years, 10 months ago by spike.
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Hi.
I developed TWAIN data source based on TWAIN protocol 2.1.
It works fine almost application except VixWin.I installed Epson printer’s TWAIN driver for the test and it is listed on the VixWin.
(Epson’s TWAIN driver protocol version is 1.8.)Here is my question.
If the TWAIN protocol of the VixWin is 1.x, DS based on protocol version 2.x is not supported?Or is there I missed something?
Please help me.
TWAIN applications, TWAIN Data Source Managers (DSM) and TWAIN Data Sources (drivers) are expected to interoperate regardless of the version of the TWAIN Specification used to create them.
That means that a TWAIN 1.5 driver will run for a TWAIN 2.3 application with a TWAIN 1.7 DSM between them. Or, conversely, a TWAIN 2.2 driver will run for a TWAIN 1.8 application with a TWAIN 2.0 DSM. Any combination is valid.
Having said that it’s possible that some poorly written applications or drivers might not work. That’s a function of their implementation, not the TWAIN standard. They should work.
The other thing that can cause this is a conflict between your DS and the app (VixWin).
The most common conflict I’ve seen is that there is a DLL used by both, but they don’t agree on the version – A DS for example expects to load xyz.dll (version 1.5) and the Application also loads xyz.dll – but expects version 3.2.Have you debugged your .DS inside VixWin, and watched the Output window when your .ds loads, to see if there are any DLLs that load from unexpected places, or don’t load when they usually would – because VixWin already loaded them?
For that matter, what happens when VixWin does enumeration – does your .ds even load?
If it does, then it must be reporting failure at some point. Step into it and find out why.
If it doesn’t even load, then that is most likely a problem with a DLL that is statically-linked to your DS, and for some reason it can’t be found when VixWin loads your .ds. Are you familiar with Dependency-walker?- AuthorPosts