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IoT Platform:Overview

Last Updated:Mar 07, 2023

If you use the C programming language to develop products, you can use Link SDK for C provided by IoT Platform to simplify the development process. The SDK allows you to connect devices to IoT Platform with ease. This topic describes the usage notes, features, and versions of Link SDK for C.

Usage notes

  • You can use Link SDK for C to connect devices to IoT Platform over the Internet.

  • You can configure Link SDK for C to implement multiple features to manage and monitor your devices. For more information, see Features.

  • You can customize Link SDK for C based on your business requirements. For more information, see Obtain Link SDK for C.

  • You can port Link SDK for C based on operating systems or hardware platforms. For more information, see Examples.

    Link SDK for C may not support devices that use a microcontroller unit (MCU) and a module for communication. In this case, you can develop the SDK based on the protocol. For more information, see the following topics:

Benefits

Category

Feature

Description

References

Device connection

Connection over MQTT

Establishes a Message Queuing Telemetry Transport (MQTT) connection between a device and IoT Platform to achieve communication.

Important

If you want IoT Platform to push messages to a device, connect the device to IoT Platform over MQTT.

Connection over MQTT

Connection over HTTPS

Establishes an HTTPS connection between a device and IoT Platform. Then, the device can submit data to IoT Platform.

Connection over HTTPS

Device verification

  • Supports DeviceSecrets-based device verification and dynamic registration over HTTPS or MQTT.

  • Supports X.509 certificates-based device verification.

Connection over MQTT

Connection over HTTPS

Connection by using X.509 certificates

Messaging

RRPC

Sends messages from IoT Platform to devices by using remote synchronous calls.

RRPC

Broadcast communication

Broadcasts messages from the IoT Platform server to devices. The devices do not need to subscribe to broadcast topics.

Broadcast communication

Device management

File management

Uploads files to the IoT Platform server for storage.

None

Device management

TSL model

Manages devices based on Thing Specification Language (TSL) models. You do not need to convert data formats during interaction between devices and IoT Platform. This way, development costs are reduced.

TSL model

Device tags

Manages devices by using custom device tags.

device tags

Device jobs

Initiates jobs on multiple devices at the same time. The jobs are categorized into the following types: jobs to set properties, jobs to asynchronously call services, and custom jobs.

Device jobs

Device shadows

Caches device status. An online device can receive commands from IoT Platform. If the device is offline, the device can request the cached commands after the device goes online.

Device shadow

NTP service

Synchronizes the time in IoT Platform to devices.

NTP service

Gateways and sub-devices

Connects the devices that do not have IP addresses to IoT Platform by using a gateway.

Gateways and sub-devices

Distribute devices

Allows you to burn information on devices that reside in different regions. This facilitates business migration.

device distribution

File upload

Uploads files to the IoT Platform server for storage.

File upload

Monitoring and O&M

Log reporting

Uploads device logs in real time.

Log reporting

OTA update

Updates devices by using IoT Platform.

  1. A device can obtain the update information that is pushed by IoT Platform and download the update package.

  2. The downloaded update package is written to the flash memory or ROM of the device and takes effect. Then, an OTA update is performed.

OTA update

Remote configuration

Remotely updates the system parameters and network parameters of the device without the need to stop or restart the device.

Remote configuration

Device diagnostics

Checks whether the device connection and communication latency are normal. If a high latency or packet loss occurs, the device can send an alert notification to IoT Platform.

None

Device attestation

Monitors the security statuses of devices.

Important

If you use the preregistration-free unique-certificate-per-product verification method, you must configure the device attestation feature.

None

Description

Version number

Description

Usage notes

References

4.x

  • Reduces the requirements for RAM.

  • Reduces the dependencies between features.

  • Optimizes user experience of developing the SDK on different operating systems.

  • Supports SDK customization.

  • This SDK version is not compatible with the previous version of the API operations of specific features.

  • You cannot connect devices to Link Living.

Important

This version of the SDK is regularly maintained and updated. We recommend that you use this version of the SDK.

3.x

Provides a tool to extract code and modify features.

  • You can extract code based on your business requirements. This facilitates code porting.

  • This version of the SDK is no longer updated and does not provide specific advanced features.

2.x

  • Adds specific IoT Platform features.

  • Requires the Linux compilation environment.

  • When you compile the SDK, you must use the method that is defined by Alibaba Cloud. Code extraction and porting are complicated.

  • We recommend that you do not use this version of the SDK.

Download a Link SDK

1.x

None.

We recommend that you do not use this version of the SDK.

None.