One of the modules that make up the Viola system is the stack fetching module. This part of the systems enables the fetching of books in a ordered fashion. The orders for fetching can come from several different sources like Interlibrary loans, call slip, requests for books to be sent to the reasearchers offices and so on.
The module relies besides the web application on an Android phone with NFC(RFID) capabilities and a via bluetooth communicating Zebra printer.