Managing parameters

Introduction to device parameters

Basically every IoT device carries some kind of dynamic state. Typical examples are the On/Off state of electromechanical relays, health indicators, for example the battery level, or the status of the network connection.

In addition, most IoT devices are equipped with some sort of configuration options that control the behavior of the device. Examples here include the control of reporting intervals or domain-specific technical configuration options like Modbus registers.

The device parameters feature of Cumulocity allows you to monitor, inspect, and modify such settings, independent of a particular device implementation.

Viewing and modififying device parameters

The Parameters tab in the device details shows the list of device parameters for a given device.

Each entry in this view can be expanded into a detailed view. This view shows the history of operations used to change this parameter. You can also investigate the parameter event history that shows corresponding value changes. In the depicted example, no recent parameter change event has been recorded.

If the parameter itself is defined as editable and the device supports updating its parameters, the corresponding Edit button sets a new parameter value. This results in a corresponding operation towards the device.

Modeling device parameters

To manipulate a device state via the Parameters tab, first model the parameter as an asset property in the Property Library of the Digital Twin Manager (DTM) application.

The image above depicts the property library with the three example parameters from before.

To model a device parameter, open the Property Library of DTM and create a new assert property.

• To create a device parameter that can only be inspected from the UI, set Applicable To (Context) to “asset” and “event”.
• To create device parameter that can be changed using operations, set Applicable To (Context) to “asset”, “event”, and “operation”.