Using

Scanner Selection
A default scanner can be specified on the command line of using skanlite -d [device name] in a terminal. If the selected scanner cannot be opened or if no default scanner is provided, a scanner selection dialog is opened.
scanner selection dialog
scanner selection dialog
The user can choose the scanner to be used and press OK to open the scanner. Pressing Cancel will cause to exit.
No scanner found
No scanner found
In case no devices were found, maybe because the scanner is not plugged in or switched off, correct that. Then the Reload device list can be used to reload the list of scanners.
Not all drivers/backends support this feature. In that case quit , connect your scanner and restart the application.