Data synchronisation between cash registries and servers

Base data for the sales activity are downloaded on cash registries inside an embedded database. This database is created on the central server and received by file transfer from the cash registry. La creation of the database and the transfer are carried out asynchronically while the operator works at the cash registry.
The file transfer is produced through a method of an object released .NET remoting or with a WebService. This transfer can be set at pre-set times during the day or forced manually by the operator.
The update of the local database is possible at any moment. The new configuration is immediately applied if a sales transaction is not running, otherwise ore when finished. if wished the cash registry can access to the articles and the customers directly on the central server in real time.
Sales data are available in real time on the central server. If not available, they are stored on the cash registry disk and transferred in asynchronous mode as soon the link with the server is restored.