Deborah Norling, January 2000

Try both showing and not showing the TWAIN UI -- in Scan Manager, set "Show TWAIN Settings Before Scan" to either Yes or No. The "Auto" parameter simply asks the TWAIN driver if it wants to show itself or not.

When you try scanning with the TWAIN UI on, be sure to set the UI to black-and-white, 300 DPI and 100% scaling. Pro cannot always command a TWAIN driver (because not all TWAIN drivers are created equal) to do these steps which is why you have to pull up the UI and manually do it. With some drivers, setting these things once makes them "stick" ... with other drivers you have to do it every time. And often, upgrading to a newer driver will make setting stick, or make Pro able to now adjust them without user intervention.

Always suspect the wrong data source. A DATA SOURCE is simply a fancy name for a chunk of program code that controls a scanner through TWAIN. Lots of data sources get installed by lots of applications in the TWAIN and TWAIN32 directories -- files with a .DS extension are data sources. Scan Manager shows you both the Available data sources -- the ones it finds on the system -- and the CURRENT data source. The current one is the important one; make sure you pick the correct current source or you will have no end of trouble.

For example, you'll often see "HP ScanJet Data Source" and Deskscan in Windows 98 systems. Windows 98 installs its own HP Scanjet Data Source which does not work with any OCR application. In this case, Deskscan should be the current data source.

Some TWAIN drivers don't actually save their settings until you return to the calling application and save there. So if a TWAIN driver's flakiness is preventing you from even initiating a scan in Pro, go to a third-party program that will scan through TWAIN, (like Imaging), scan through TWAIN, save the result in the third-party program as a TIFF and make sure Pro will OCR that TIFF.

There are three reasons for making sure Pro can OCR that TIFF. First, you give the user a work-around if you can't get the scanner to work in Pro. Second, you want to be sure the TWAIN settings are correct for pro -- the 300 DPI, B/w, 100% scaling. If those settings aren't correct, you can still have a good image but an image that won't OCR, and you'll know this if you try to OCR the resulting TIFF. and if you can't scan through Pro, this is another way to check. Third, the act of saving the results of the scan as a TIFF forces some recalcitrant TWAIN drivers to finally permanently save the settings you made through the UI.

Remember that many manufacturers give their TWAIN component and the program for controlling the scanner the same name, but you are actually running two different programs. For example, Deskscan has two components, and so does PrecisionScan. When you call up these HP programs through Start-Programs, you ARE NOT running the TWAIN component. You can make changes all day in PrecisionScan and Deskscan and have them not work, because they are not being made through the TWAIN UI. You must call up the TWAIN UI at the time you scan in order for changes you make to the settings to affect the results sent through TWAIN back to the calling application.

If Pro can OCR the sample.TIF fine, but gives invalid page faults or general page faults or crashes when trying to scan, Re-install just the Scan Manager. If that doesn't work, clear out the TWAIN, TWAIN32 and PIXTRAN folders -- all three are found under the Windows folder, so you eliminate any old or corrupted scanner drivers. Leaving the folders on the system, but empty, re-install the manufacturer's drivers. Then set up the scanner again in Scan Manager, making sure you have the correct current data source.

Remember that errors when starting Pro are sometimes the result of scanner trouble, so try starting Pro after you've set it to No Scanner in Scan manager just to test for this.

When you re-install scan manager, you should do an uninstall first, and completely shut down. When you re-install, you should always shut down afterwards because the Scan Manager install doesn't write its registry entries until you actually shut down the computer.

When you go between Scan Manager and Pro, be sure the customer completely closes Pro first, then completely closes Scan Manager after making changes. If your customer simply minimizes one and goes to the other and toggles back and forth between minimized copies of Pro and Scan Manager, adjusting settings won't appear to work. Pro checks the Scan Manager settings when it Starts, which is why if you adjust them, you need to start Pro all over again!

If none of this works, begin to systematically change the scanner properties in scan manager. For example, try troubleshooting with the Close Data Source after Each scan property set first to Yes and then to No. Change one property at a time.

If you are communicating with the customer via email, suspect that he's taking shortcuts and not following your instructions properly. For example, he might be minimizing Pro and not restarting it after adjusting Scan Manager settings -- he might be trying to use Scan Manager after installing, but not completely shutting down and restarting Windows first; he might be forgetting to check what his *CURRENT* data source in Scan manager is set to.

Some TWAIN drivers have a nasty habit of not telling the system they are finished. They don't "close" and so the next program that wants to use the scanner thinks the scanner is busy. To troubleshoot for this, scan in another TWAIN-compliant application and complete the process, including saving the image and properly exiting the application. Then immediately shut down all the way, restart Windows and run Pro first. If Pro works BEFORE you use another scanner app, but not *AFTER* you know the data source isn't properly closing itself.

Don't forget to check our spreadsheet of supported scanners to see which version of the data source we've tested with, whether the ADF worked and whether it scanned in color. Don't forget to read the Scanner Setup Notes which are now IN HTML. If your customer does not have the most current version of Pro, have him download the latest scan manager from our website.