This topic contains 7 replies, has 4 voices, and was last updated by gabe 10 years, 11 months ago.
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Tuggie,
I accidentally deleted your user while cleaning the *pammers.
I’m really sorry!
Hilary – TWAIN Admin
Still having problems with this. Please can anyone help.
does this happen with only your program or do other (Ui-less) programs exhibit the same behavior?
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The test program provided with delphitwain does the same thing.
lets try this another way, do programs not using that library work exhibit the same behavior?
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Sorry, being dense!
I’ve downloaded a couple of other programs and tested these. One of them cannot be made to do this at all, but it always unloads the source after scanning, which I can tell because loading the source causes its splash screen to display. The other program can be made to do this as it only unloads the source when told to do so.
What I don’t understand is that if I send the command enable source to the scanner using the WIA-HP Scanjet 4800 driver, a scan is produced and the source’s status is set to disabled. If I then set the source to enabled again, a second scan is produced. Using the same procedure with the HP 4800 Series Twain driver, the first scan is produced as before, but setting the scanner to enabled a secod time, does not cause the scanning process to take place with the previous scan simply being downloaded again. With this driver, the scanner must be unloaded and re-loaded between scans. I assum this is a solution, but I’d like to know why this happens. The HP UI does not unload the scanner between scans, as the splash screen does not display between scans.
but the Hp Ui doesn’t have to play by the rules – it could be using Custom triplets or even non-twain functions.
The twain.log in %temp% should tell you what it happening, look thru the %temp%twain.log when you control the device and look at it when the Hp Ui does. What is different?
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