IoT Core Instance

Resource partitioning unit of the IoT core suit IoT Core. Each instance is a separate namespace, with its own identity, which is the Core ID. Different instances shall be isolated with each other.

Device

A cloud port mapping of the entity world, which is the minimum unit of IoT Core connection, and every device can own its identity (DK/SK) and theme list.

MQTT

MQTT (Message Queuing Telemetry Transport) is a message transmission protocol in Publish/Subscribe mode based on the binary client-server architecture of message, which IBM first proposed, and now has become the prevailing specification of the industry. It is more in line with the machine-to-machine communication (M2M) and IoT environment (IoT).

DK（Device Key）

The key required for device connection is used to generate the username required by MOTT connection.

SK（Device Secret Key）

The key required for device connection is used to generate the password required by MOTT connection.

Shadow

The device shadow reflects one object (device) in the physical world and is the [shadow] of the object on the cloud or [digital twin]. During the operation, the object reports the monitoring value to the shadow, which stores the device's last reported status with a json file, and you can access it directly through MQTT or HTTP. At the same time, the thing shadow also provides counter-control functions.

Template

The device template is used to create a kind of device in batch, and the theme template is available currently. Devices are created with the same theme template and have the same privilege for the theme.

Topic

The topic is available in the MQTT client. Topic rules allow strings to contain wildcard characters "#" or "+".

Operation Privilege

You can customize the topic operation privilege to the device in theme templates. IoT Core supports "Publish" and "Subscribe", two privileges based on the MQTT protocol.

Rule Engine

The rule engine is the message routing center for the IoT core kit, so you can use it to receive the message released through the MQTT topic. You can set the filtering conditions and query statements for message filtering and format conversion in the rule. Afterward, the rule engine forwards the message results to other devices, cloud-based computing, storage, or message queuing products, and user-defined services, connecting the devices, services, and applications in series.

Rule

You can comprehend the rule as the strategy for message routing and forwarding. For each rule, you must set the message source topic and data destination. Meanwhile, you can set the filtering conditions and query statements to filter and convert the messages. You can create several rules under each IoT Core instance to meet different business logic requirements.

Data source

In the rule, you must configure data to configure the data source to indicate the messages to be processed. The data source may be an arbitrary topic under the IoT Core instance and supports the wildcard. After being set as the data source, the rule can subscribe to messages and process the received messages.

Data destination

The data destination is the target product or service to which the rule processes and forwards the messages. In one rule, you can set several data destinations.

Filtering conditions

When the rule engine routes the messages, it first judges the message filtering conditions. Then, it forwards the data meeting the filtering conditions to achieve the subsequent format conversion. Afterward, it forwards the data to the data destination.

Query statement

The rule engine can convert the message format. With a series of query statements defined in the rule engine to operate the JSON, it is easy to configure the format conversion rules meeting the business requirements without the need to program it. For example, it can convert the messages to a data format that meets the TSDB write requirements and a data format that allows you to write the data into the RDS.