Qbuster function allows you to scan item into the PDE and then recall them at the register at a later time, it could be used for a number of reasons such as
1. packing and selling on line orders, items can be scanned from a pick list then recalled later on the pos to sell them to an account etc
2. to reduce the queue at a register, if your store has a limited number of tills you could also use the Qbuster to pre scan items that the customers have and then recall them at the pos when the customer is ready to be served, this will save time at the pos as the only thing left to do will be to collect their payment for the goods
3.you could setup a self shop and scan system within your store, you could hand customers a PDE and let them scan their own goods as they place them into their trolly, then when they arrive at the checkout their items will already be at the pos thus saving time
