Scanning
On the Scanning node in the Policy Properties dialog, you can specify a scanner that should be used when one is required by a published application:
Use. Allows you to select a scanning technology. RAS Universal Scanning uses TWAIN and WIA redirection allowing an application to use either technology depending on the hardware type connected to the local computer. If you select None, scanning will disabled.
Redirect Scanners. Select scanners attached to your computer for redirection. You can select All (all attached scanners will be redirected) or Specific only (only the scanners you select in the provided list will be redirected).