The Device Access defines abstraction that allows configuration of devices and device items. This abstraction allows to configure the device name, device tags, device attribute as well as device item name, device item tags, device item attributes and functional properties of the device items. Also the configurations allow to invoke operations on the device items. Every configuration has unique identifier that contains the UID of the configuration and its version.

In every configuration it can be specified for which device or set of devices, as well for which device item or set of device items the configuration should be applied to. This is achieved by defining the filtering mechanism. If set of configurations matches a device, then the configuration priority is considered. The one with the highest priority is applied. If there is no defined filter, the configuration must be applied on every device and device item. There is also a way to set how the configuration will be re-applied in a case of a failure.

For example if there is a failure in the network connection or the device is not available, the information to be specified is:

• the count of attempts the configuration is tried to be applied;
• the interval between each retry;
• if the whole configuration should be re-applied over again.

The different configurations are provided by a DeviceConfigAdminSpi service. The DeviceConfigAdminSpi (com.prosyst.mbs.services.da.spi.config.DeviceConfigAdminSpi) is an OSGi service that provides functionality for communication between Device Access and third part bundle which manage the device configurations. The Device Access gets available configurations through DeviceConfigAdminSpi. The Device Access is notified when new configuration is provided or any of the provided configurations are updated, through DeviceConfigAdminCallback (com.prosyt.mbs.services.da.spi.config.DeviceConfigAdminCallback). Only one implementation of this OSGi service can be active in the system.

The DeviceConfigAdmin (com.prosyst.mbs.services.da.config.DeviceConfigAdmin) is an OSGi service that provides information about the available DeviceConfigurations (com.prosyst.mbs.services.da.config.DeviceConfiguration) and ConfigurationInfos (com.prosyst.mbs.services.da.config.ConfigurationInfo) in the Device Access. This service is register by Device Access when there is a DeviceConfigAdminSpi service registered in the system.

The Device Access provides default implementation of the device configuration – Device Access Config Bundle.