Terms
This topic describes the basic concepts of IoT Platform.
Instances
An instance provides resource management features for products, devices, and rules in IoT Platform.
Term | Description |
Enterprise instance | An Enterprise instance is a purchased instance of IoT Platform that is deployed in an Alibaba Cloud VPC. You can purchase multiple Enterprise instances for one account. |
Public instance | After you activate IoT Platform, a public instance is provided for trial use by default. Public instances are deployed in the Alibaba Cloud classic network. Public instances are classified as earlier-version public instances and later-version public instances. For more information, see Instance overview. |
Device management
Term | Description |
Product | A collection of devices. A product usually refers to a group of devices that have the same features. IoT Platform issues a globally unique ProductKey for each product. |
Device | A specific device that belongs to a product. IoT Platform issues a unique DeviceName within the product for the device. A device can connect directly to IoT Platform, or connect as a sub-device through a gateway. |
Group | IoT Platform lets you create device groups. A group can contain devices from different products. You can use device groups to manage devices across products. |
Gateway | A device that can connect directly to IoT Platform and manage sub-devices. A gateway can act as a proxy for sub-devices to connect to the cloud. |
Sub-device | A type of device. A sub-device cannot connect directly to IoT Platform. It can only connect through a gateway. |
Device certificate | A device certificate is a combination of a ProductKey, a DeviceName, and a DeviceSecret.
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ProductSecret | The product key that IoT Platform issues. It is usually paired with the ProductKey and can be used for one-product-one-secret authentication. This parameter is important. Keep it confidential and do not disclose it. |
Device X.509 certificate | IoT Platform supports X.509 digital certificates for device identity verification. After you create a device that uses X.509 certificate authentication, IoT Platform issues a corresponding X.509 certificate for the device. The certificate information includes the X.509 digital certificate (Certificate), the X.509 certificate ID (CertSN), and the X.509 certificate key (PrivateKey). |
Topic | A topic is a UTF-8 string that acts as a medium for publishing (Pub) and subscribing (Sub) to messages. You can publish messages to or subscribe to messages from a topic. |
Topic category | A collection of topics for different devices under the same product. The ${productkey} and ${deviceName} wildcards are used to represent a unique device. A topic category is applicable to all devices under a ProductKey. |
Publish | A permission type for operating on a topic. The corresponding English name is Pub. This permission lets you publish messages to this type of topic. |
Subscribe | A permission type for operating on a topic. The corresponding English name is Sub. This permission lets you subscribe to messages from this type of topic. |
RRPC | Full name: Revert-RPC. Remote Procedure Call (RPC) uses a client/server model. Users can remotely request services without understanding the underlying protocols. RRPC lets the server-side send requests to devices and enables devices to send responses. |
Tag | Tags are classified into product tags, device tags, and group tags.
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Alink protocol | The communication protocol between devices and the cloud that is defined by Alibaba Cloud. |
Thing Specification Language model | A description of a device's features in the cloud, including its properties, services, and events. IoT Platform uses a Thing Specification Language (TSL) to define TSL models. TSL uses the JSON format. You can assemble the data to be reported by a device based on TSL. |
Property | One of the feature models of a device. It is generally used to describe the runtime status of a device, such as the current environmental temperature read by an environmental monitoring device. Properties support GET and SET requests. An application can initiate requests to read and set properties. |
Desired property value | Use the desired property value feature to set the device property values that you want. If the device is online, the property values are updated in real-time. If the device is offline, the desired property values are cached in the cloud. After the device goes online, it retrieves the desired property values and updates its properties. |
Service | One of the feature models of a device. It is a capability or method of a device that can be called externally. You can set input and output parameters. Compared with properties, services can implement more complex business logic with a single instruction, such as executing a specific task. |
Event | One of the feature models of a device. It is an event that occurs at runtime. An event usually contains notification information that needs to be perceived and processed externally. It can contain multiple output parameters. For example, information about the completion of a task, or the temperature when a device fails or an alert is triggered. Events can be subscribed to and pushed. |
Data parsing script | For devices that use pass-through or custom data formats, you must write a data parsing script in the cloud. The script converts the binary data or custom JSON data reported by the device into the Alink JSON format that IoT Platform supports. The script also converts the Alink JSON data sent from the platform into a format that the device supports. |
Device shadow | A JSON document that stores the current status information of a device or application. Each device has a unique device shadow in the cloud. You can use the device shadow to get and set the device status through Message Queuing Telemetry Transport (MQTT) or HTTP, regardless of whether the device is connected to the internet. |
Device connection
Term | Description |
One device, one secret | Each device is flashed with its unique device certificate (ProductKey, DeviceName, and DeviceSecret). When the device establishes a connection with IoT Platform, IoT Platform authenticates the device certificate. |
One product, one secret | All devices under the same product can be flashed with the same product certificate (ProductKey and ProductSecret). When a device sends an activation request, IoT Platform authenticates the product certificate. If the authentication is successful, IoT Platform sends the information required for the device to connect. The device then uses this information to establish a connection with IoT Platform. |
Message forwarding
Term | Description |
Message forwarding | Create and configure rules to implement server-side subscriptions, data forwarding, and scene orchestration. |
Server-side subscription | The server-side subscribes to all types of messages under a product: device-reported messages, device status notifications, messages about sub-devices discovered by gateways, device lifecycle change messages, and device topology change messages. Two methods are supported for server-side subscriptions:
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Data forwarding | The data forwarding feature of IoT Platform can forward data from a topic to other topics or other Alibaba Cloud services for storage or processing. |
Scene orchestration | Scene orchestration is a visual programming method for developing automated business logic. You can visually define interaction rules between devices and deploy the rules to the cloud or the edge. |
Data services
Term | Description |
Data source | Data services access data from data sources to perform operations such as data synchronization and backup, query and analysis, and data configuration. Data service data sources include device data sources and API data sources. |
Device data source | A device data source contains data from custom topics and TSL model data reported by devices. |
API data source | Using an API data source, you can import local data into IoT Platform for further analysis. |
Data pipeline | A method of data pre-processing. You configure expressions or filters to output specified data tables. |
Data API | Using data APIs, you can obtain required data and achieve system-level integration between your server and IoT Platform. Data APIs include the following:
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Data asset | The general term for all data sources and data information owned by an individual or enterprise. |
Data source | Create data analytics reports from different data sources, such as metrics, domains, and data tables. |
Storage table | A table used to store data. It can be used as a data source for visual data reports or data APIs. It includes the following types:
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SQL analysis job | Write SQL statements to query data in storage tables, configure a policy to execute the queries, and schedule the generation of the required data. |
Device tag | Valuable, measurable, and readable data information for all products in IoT Platform, such as product or device properties and tags. |
Metric | A unit or method used to measure the degree of development of something. It is also often called a measure. Examples include population, GDP, revenue, user count, profit margin, retention rate, and coverage. |
Derived metric | A derived metric is obtained through summary calculations such as sum and average under certain preconditions, such as time, application scope, and business scenarios. The time range for a derived metric (time constraint) is abstracted as a time modifier. Other constraints are abstracted as business modifiers. Therefore, a derived metric consists of three elements: time modifier (required) + business modifier (optional) + atomic word (required). |
Downstream metric | All metrics derived from a specific metric are called its downstream metrics. If the output table of an SQL analysis job is the query object of another analysis job, the latter job is a downstream metric of the former. |
Metric definition | Define the purpose of a metric by setting its elements, business description, subject area, entity, and unit of measurement. |
Metric configuration | Configure the calculation logic for generating data for a defined metric. |
Metric domain | The object to which a metric belongs. It is used to classify and manage metrics. |
Entity | A specific object in a metric domain that has a business relationship, such as a specific product or device. Based on the subordinate relationship between metric domains, a specific object in a subdomain is a sub-entity of a specific object in the domain. For example, a specific device under a specific product is a sub-entity of that product. |
Atomic word | The smallest unit of measurement with business semantics in a metric, such as temperature, humidity, and unique visitors (UV). |
Time modifier | Used to set the time range for metric statistics, such as last 1 day, last 7 days, month-to-date, year-to-date, and all time. |
Business modifier | Used to describe the business data summarized by a metric. |
T+1 scheduling | Calculates stored and backed-up data in T+1 mode. |