DA API System Architecture Diagram

The following diagram shows the main components in the Device Access module from the perspective of the DA API implementation.

Functional Item Management

The Functional Item Management is the main external module in the DA API implementation. The whole implementation is based on the Functional Item specification. The DA API implementation uses the following Functional Item components:

• Functional Item Management Web Admin
• Functional Item Management JSON-RPC
• Functional Item Management Commands
• Functional Item Management RESTful Web Services

The DeviceAdmin, Device and DeviceItems are Functional Items.

Device Admin

The DeviceAdmin is used for:

• Obtaining information abut protocol adapters.
• Creating new devices if the protocol adapter supports it. The Device is created and registered with a set of functionalities (Device Items).
• Removing existing devices if the protocol adapter supports it. The specific Device and its Device Item will be removed based on their Device UID.

The DeviceAdmin extends the FunctionalItemFactory. The interface (com.prosyst.mbs.services.da.DeviceAdmin) will be registered only when the DA API implementation is enabled. The DA API implementation is available by default.

The DeviceAdmin has a specific UID and it is possible to assign a name or tags. The default value for name is "Device Admin".

The DeviceAdmin has a single property named adapterInfos and the following operations:

• create
• createDevice
• remove
• removeDevice
• reCreateDevice
• getAdapterInfos
• cancelRemove

Device

One Device is a representation of one physical device. The Device abstracts its physical device and provides the following common information related to the specific device:

• UID
• name
• tags
• status
• error
• time stamp when a device is created
• adapter name
• adapter version
• firmware vendor
• firmware version
• hardware vendor
• hardware version
• model
• secure
• serial number

The unified device representation in Device Access is achieved with the help of the information above. The Device functionality is represented by a Device Item. Each Device may have zero or more Device Items.

The Device and its Device Items extend the Functional Item.

Device Item

The Device Item represents the Device functionality. Each Device Item object has to implement a specific Functional Item element. It will be registered only when there is a SPI adapter object. This means that if the adapter is not registered, the Device will be registered with offline status and thus its Device Item will not be registered.

Every Device Item has specific:

• UID
• name
• tags
• attributes

Every Device Item attribute contains an additional attribute which is the Device UID of the Device Item. Every Device Item has specific functional properties and operations that define its functionality.

Device Configuration

Device Configuration represents the mechanism to configure the device and its device item. The Device Access defines an internal configuration Java API and defines a XML format for applying the configuration mechanism. The Device Configuration supports device configuring by: name, tags and attributes, and item configuring by: name, tags and attributes. Also supports a set of device item properties and invoking device item operations.

Device Item Mapping

Device Item Mapping introduces the way for item representation into another item. The general mapping idea is: when an adapter provides a device with some functionality (Device Item in the context of Device Access) and the user wants to change its functionality in a similar way to meet his desired needs, the Device Item Mapping takes care of this use case and makes it possible. In the Device Item Mapping context there is a Source Item (this is the item which comes from the adapter) and a Target Item (this is the user's item) and both of them are Functional Items.

Device Item Mapping defines an XML format that describes how the mapping will be done between them. The mapping consists of:

• property to property mapping
• property to operation mapping
• operation to property mapping
• operation to operation mapping

During their whole lifecycle, the Source Item and Target Item are part of one Device. Their behavior depends on the content in the XML file.

Device Management RESTful services

Device Management RESTful services are used for remote management of devices that are available in the system. They define a set of resources that are used to represent devices, protocol adapters and their capabilities, valid procedures that can be performed over those resources and relevant events that may be generated if a change in the state of the resources is detected.

The main resource in the Device Management RESTful services is the DeviceResource. This is the representation of a Device used for remote communication. The DeviceResource contains the following common resources - AdapterResource and ItemCollectionResoure. The ItemCollectionResource is provided by the Functional Item Management RESTful service.

The Device Management RESTful services support creation of devices via appropriate CRUD operations over device resources. The device resource representation is transferred in JSON serialization format.