In the supermarket self-service price check application, consumers just need to put the bar code on the outer package of pre-packaged goods on the commodity information inquiry machine "bar code scanning port", the price check machine screen will automatically display the price and name of the commodity. Since the price inquiry machine is connected to the data of the supermarket's cash register settlement system, it can ensure that the commodity price is the latest adjusted price. And the price tag can also be compared with the price query machine, to prevent the price tag and the latest change of the price is inconsistent and cause trouble to consumers.
