Introducing device twins
Device twins are a way of storing state data of your devices. They are JSON documents that contain desired properties, reported properties, and tags. Device twins are extensively used in IoT to store device metadata in the cloud, report the current state of your devices, synchronize the state of long-running processes, and query device metadata.
For example, you can use a device twin to store configuration settings for each device. This can include things such as sampling intervals, alert thresholds, and communication settings—for instance:
Sampling interval: 10 minutes
High temperature alert threshold: 30°C
Low humidity alert threshold: 20%
The following screenshot shows a sample device twin for a device:
Figure 4.1: Sample device twin
The preceding code is also available on the GitHub repo in the Chapter04 folder.
Tags are set by a backend application or through IoT Hub. They are used to organize and...
