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The VRS TWAIN driver from Kofax is included as part of the VRS (VirtualReScan) product installation. Without the complete product installation is doesn’t work.
There is no requirement to have a Kofax Adrenaline SCSI board in order to use the VRS TWAIN driver. However, some VRS certified scanners are only supported when used with an Adrenaline board. These are, though, larger production scanners that include a hardware VRS board (Fujitsu fi-4860, fi-4990; Bell & Howell 8000 Spectrum to name a few).
In addition, there is no royalty, though, as I first mentioned you can’t include the TWAIN driver as it won’t work without the complete package. In addition, VRS is licensed depending upon the model of scanner being used so you have to purchase a license for each scanner you want to use with VRS. To that same end, VRS works best when used with scanners that have been certified. The reason for this is that VRS is designed to provide superior image quality and it has to be able to control the image being provided by the scanner. You can see a complete list of certified scanners at http://www.kofax.com/products/virtualrescan/specs.asp.
You can, though, use nearly any scanner with VRS but the image quality will not be optimum. There are, though, two criteria a scanner must pass before it can be used with VRS. First, the scanner must have either an ISIS or TWAIN driver. VRS works better with ISIS drivers because of ISIS’s ability to provide easy access to Advanced Features. In addition, as most people on this forum can attest to, TWAIN drivers are not all alike. VRS will do its best to interface with a TWAIN driver, but sometimes there are problems that can’t be overcome. Second, the scanner must output a 256-level (8-bit) Grayscale image as a single bitmap. This is rather important as VRS uses Grayscale data to generate the Black & White image requested by the application.
As for limitations within the VRS TWAIN driver there are, sadly, some. First, it doesn’t support frames. Unfortunately, if you try to set one it doesn’t complain but will return the image of the paper size last set. Second, the CAP_FEEDERLOADED always returns True. This was a design decision made many years ago when not a lot of scanner drivers supported this functionality. It may be supported in the future, but will be limited to what the underlying scanner driver allows. Third, VRS will scan a page before it sends a MSG_XFERREADY. This is different then a lot of other Data Sources in that they send a MSG_XFERREADY before scanning a page. Those are the ones I can think of at this time. Others in this forum may have more indepth experience and may be able to provide additional information.
Finally, the name of the TWAIN data source is always “Kofax Software VRS – TWAIN” regardless of the model of scanner configured. This simplifies those applications who don’t display the standard TWAIN source selection dialog. VRS knows which scanner to communicate with based upon the KSM utility in the Control Panel. This is the Kofax Source Manager and is used to create sources that communicate with either a TWAIN, ISIS, or a Kofax Hardware VRS driver. The “Default” source is the one that the VRS TWAIN driver will use. When VRS is installed and a certified scanner is selected from the list of scanners displayed all of the necessary sources are created automatically and one of them is set as the “Default”. If the user has to configure a compatible scanner they must create these sources automatically.
You can find addition information on VRS from the manuals available on Kofax’s web site at http://www.kofax.com/support/IP/VRS/4.0/manuals.asp.
I hope this helps.