- Device Networks and Locations
- Types and Templates
- Gateways, Devices, Smart Objects, and Resources
DDM represents physical IoT hardware as virtual twin devices organized in a conceptual hierarchy:
Device Networks and Locations
Device Networks are the top element under which other objects such as Locations, Gateways and so on are organized. A Device Network can represent a Customer, a Site, or some other high level concept.
Locations are where Gateways and Devices are placed in a loose sense: a Location can be a specific geographical place such as Building 13 Main Entrance, but it can also be movable entities like Truck. In addition, Locations can be entire classes of units such as Desks or Recycling Units.
Types and Templates
When registering a Gateway, Device, Smart Object, or Resource, you must choose a Hardware Type that determines what properties it should have, and optionally a Hardware Template.
Hardware Types is an umbrella term for Gateway Types, Device Types, and so on. You can create and use Hardware Types in the DDM interface. It is also important to distinguish between a type (for example, a Device Type) and an actual, instantiated entity of that type (for example, a Device).
Once an entity has been registered with a given type, you cannot choose a different type for it. If you edit the type itself, all entities of that type—including those created before the editing—will receive the new settings. This is useful when you need to roll out changes to an entire class of entities.
Hardware Templates can be added to specific Hardware Types to provide additional “sub-types” that share the same basic properties but with some differences. All Hardware Types have a default template that is used if you do not select a custom one.
Changes to a template also affect the instances that use the template. However, if a specific instance has been changed by editing one or more setting values inherited from the template, the link to the template is broken, and an icon is displayed in the Dashboard at the right of the changed setting. In this case, this instance will not be impacted by changes to the template.
Note: The link between an instance and the template link can be re-established by clicking the icon. The values inherited from the template are then restored to the instance.
The following example shows a Device instance where the settings identity and preSharedKey have been manually changed.
Clicking the icon at the right of the respective setting replaces the current value with the default value stored in the Template, and re-links the instance to the Template.
Gateways, Devices, Smart Objects, and Resources
These entities are where telemetry data is collected, stored, and transmitted.
Gateways facilitate communication from Devices to DDM. Devices transmit data through various technologies such as Wi-Fi, Bluetooth etc. Gateways receive this data and communicate it to DDM using the necessary protocol.
Devices are representations of IoT hardware devices, which in many cases are equipped with multiple sensors. Sensors, in turn, are represented by Smart Objects (see below). Devices belong to a Location and a Gateway, and contain Smart Objects.
Smart Objects represent hardware sensors that measure things like temperature, pressure, motion etc., but they can also be abstract constructions such as Firmware Update. Smart Objects contain Resources.
Resources belong to Smart Objects. They store data from measurements, for example 23, and units such as Celsius.