State data cannot be reported against the device unless the values in the state report have first been defined as attributes. Furthermore, the format of the data per attribute must conform to the data type for the attribute.
A device’s attributes can be viewed, created, and modified by doing the following:
- Navigate to a Device page.
- Select the “Attributes” tab.
Attribute Name: Must contain only uppercase and lowercase letters, numbers, hyphens (-), and underscores (_).
Many applications will use the same attribute name (such as
temperature) across multiple devices. You may perform aggregations on attributes of the same name across devices.
Optionally, you can choose “Include optional description fields” to include an attribute’s description and tag fields when creating new attributes.
For system devices, this checkbox is not present and the optional fields are always visible.
When creating an attribute, you must choose a data type. The type should be determined both by the expected format of the data you will report against the attribute and how you wish to utilize and visualize that data.
Number attributes only accept integers or floating points, positive or negative (or zero).
This is the most commonly used attribute data type within the platform. Number attributes can be used to store, for example, temperature and pressure information, voltage and amperage, and many other types of numerical data common to an IoT application.
Booleans are best used to answer yes (
1) or no (
0) questions, such as whether a machine is running or if a room is occupied.
String attributes are for reporting alphanumeric characters and symbols that cannot be cast as numbers, booleans, or GPS coordinates.
Blob attributes are for reporting large amounts of arbitrary binary or image data. They are reported as base64 encoded strings. You must also provide a content-type to specify a file type for your Blob Data.
GPS attributes are used specifically for tracking the position of resources in the physical world.
While the raw data is reported as a string, it must adhere to one of four strict formats to be accepted as a state report:
Decimal Degrees - (latitude, longitude)
Degrees Minutes Seconds - (also known as Sexagesimal)
Systems are a special device type that allow you to build complex, hierarchical relationships between your application’s devices and to construct a ”digital twin” model of your device.
However, System device attributes don’t report data in the same manner as other device attributes. Attributes for systems are calculated from the attributes of other devices.
After creating an attribute, a device attributes table will be displayed showing the attribute name, data type, last reported value, and last reported time. The attributes last reported value and time will be refreshed every 30 seconds. You may also perform a manual refresh.
Depending on the data type of the attribute, the last reported value may be formatted differently. For example, a boolean attribute will be displayed as either
False. A number attribute will be displayed as a number, and a string attribute will be displayed as a string. A blob attribute will be displayed as a link to the blob. A GPS attribute will be displayed as a link to Google Maps.
In the case that you have a large number of attributes, you may filter the attributes that are displayed by entering the name of the attribute in the text input located above the table.
You will also be able to add, edit, and delete existing attributes from this table as long as you have collaborator or higher permissions.
A System device also displays the current “System Attribute Reporting Behavior” setting shown below.
Click on the attribute name displayed in the table to view the attribute’s details.
You cannot change an attribute’s name or data type once the attribute has been created. However, you can change the attribute’s description or tags.
For system devices, you may change its attribute calculation methods such as aggregation and child attributes.
Warning: Deleting an attribute from a device removes all data that has been reported against that attribute for the device.
To delete an attribute:
- Click the “Remove” (trash can) icon. This will display a confirmation modal.
- Click the “Delete Attribute” button.
Click the “Add” button located above the attributes table over on the righthand side of the screen to add a new attribute.
A new attribute form will be displayed where you can enter the attribute name, data type, description, and attribute tags. For system devices, you can select the aggregation method for the last reported value of each child device attributes. After selecting the aggregation method, you can to choose which child device attributes to include in that calculation.
Clicking on “Add another attribute” checkbox will allow you to add additional attributes without closing the modal after submission.
Each device has a limit of 256 attributes.
For information concerning aggregation methods, see the References: Aggregations Section.
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