ThingsGateway Plugin System Overview

Relevant source files

• Directory.Build.targets
• PackNuget.props
• README.md
• ThingsGateway.Plugin.slnx

Purpose and Scope

This document provides a high-level introduction to the ThingsGateway Plugin repository, explaining its role as an extensible industrial IoT edge gateway system. It covers the plugin-based architecture, plugin categories, build infrastructure, and core design patterns that enable protocol support, data collection, and cloud integration.

For detailed information about specific subsystems:

• Build system and versioning strategy: see Build System and Configuration
• Plugin base classes and lifecycle: see Plugin Base Classes and Lifecycle Management
• Data flow architecture: see Variable Runtime and Data Flow Architecture
• Specific plugin implementations: see Data Collection Plugins and Data Publishing and Distribution Plugins
• Custom plugin development: see Plugin Development Guide

Sources: README.md14-32

What is ThingsGateway Plugin Repository

The ThingsGateway Plugin repository contains protocol and integration plugins for the ThingsGateway industrial IoT edge gateway platform. It is a separate repository from the core gateway platform, allowing independent development and versioning of plugins.

Repository Identity

Property	Value
Repository URL	https://gitee.com/diego2098/ThingsGateway (Gitee primary), https://github.com/ThingsGateway/Plugin (GitHub mirror)
License	Apache-2.0
Core Dependencies	ThingsGateway.Foundation, ThingsGateway.Gateway.Application
Distribution Model	Independent NuGet packages
Target Frameworks	net10.0, net8.0, netstandard2.1, netstandard2.0, net462, net6.0
Package Tags	ThingsGateway, Diego, Blazor, IOT, 设备采集, 边缘网关, 物联网

The repository is organized as a plugin ecosystem where each plugin is packaged independently as a NuGet package (e.g., ThingsGateway.Plugin.Modbus), enabling selective installation based on deployment requirements. The Chinese README describes it as "ThingsGateway 的插件库，包含各种协议功能插件等，用户可以根据需求选择性安装使用" (ThingsGateway's plugin library, containing various protocol function plugins, allowing users to selectively install as needed).

Sources: README.md14-18 README.md22 PackNuget.props13-17

Repository Structure and Plugin Categories

Solution File Structure

The repository is organized as a single solution file ThingsGateway.Plugin.slnx containing 10 plugin projects:

Sources: ThingsGateway.Plugin.slnx1-23

Plugin Categories

The repository contains four main categories of plugins:

Category	Purpose	Base Class Pattern	Example Plugins
Protocol Collection	Read data from industrial devices and external systems	CollectBase	OpcUaMaster, ModbusMaster, MqttClient
Data Publishing	Publish/serve collected data to external systems	BusinessBase, BusinessBaseWithCacheIntervalScriptAll	OpcUaServer, MqttServer, KafkaProducer, RabbitMQProducer
Database Persistence	Store real-time and historical data	BusinessBaseWithCacheIntervalVariable with IDBHistoryValueService	SqlDBProducer, TDengineDBProducer
UI Components	Debug and configuration interfaces	Blazor ComponentBase	OpcUaImportVariable, address debug components

Sources: README.md24-32

Plugin Architecture Pattern

Base Class Hierarchy

All plugins follow a common lifecycle pattern defined by their base classes:

1. InitChannelAsync() - Initialize connections to external systems (e.g., OPC UA sessions, database connections, Kafka producers)
2. ProtectedStartAsync() - Start plugin operations (e.g., begin subscriptions, start listening)
3. ProtectedExecuteAsync() - Continuous execution loop for periodic operations (polling, publishing)
4. DisposeAsync() - Clean up resources and close connections

The base class hierarchy determines plugin behavior:

• CollectBase plugins read from external sources and update VariableRuntime
• BusinessBase plugins consume GlobalData shared state
• BusinessBaseWithCacheIntervalScriptAll adds caching and dynamic C# script support
• BusinessBaseWithCacheIntervalVariable provides variable-level caching for database persistence

Sources: Based on high-level architecture diagrams provided in context

Data Flow Architecture

Hub-and-Spoke Pattern

ThingsGateway uses a hub-and-spoke data flow architecture:

1. Collection plugins read from external sources and update VariableRuntime (the central hub)
2. GlobalData provides shared read access to all plugins via IdVariableRuntimes collections
3. Distribution plugins consume GlobalData state and publish/persist to external systems
4. Bidirectional communication is enabled via GlobalData.RpcService.InvokeDeviceMethodAsync() for write operations

This pattern enables many-to-many data routing: a single Modbus device can simultaneously serve data to an OPC UA server, publish to Kafka, and persist to SQL database, all without direct plugin dependencies.

Sources: Based on high-level architecture diagrams provided in context

Build and Distribution Model

Versioning Strategy

The repository uses independent semantic versioning for different component layers as defined in Directory.Build.props:

Component	Version	MSBuild Property	Purpose
Foundation	12.5.5	$(FoundationVersion)	Protocol implementations and utilities
Gateway	12.5.4	$(GatewayVersion)	Core gateway platform
Plugin	12.5.6	$(Version)	Plugin implementations

This versioning strategy allows core platform updates without forcing plugin upgrades, enabling flexible deployment strategies. The version numbers are referenced throughout project files to maintain consistency across the ecosystem.

Sources: Based on high-level architecture diagrams indicating Version 12.5.6 as current plugin version

Multi-targeting Strategy

The README specifies: "默认支持net10.0/net8.0。驱动库支持netstandard2.1/netstandard2.0/net4.62/net6.0" (Default support for net10.0/net8.0. Driver libraries support netstandard2.1/netstandard2.0/net4.62/net6.0).

This multi-targeting strategy enables:

• Modern runtime support: net10.0, net8.0 for latest language features and performance
• Driver library portability: netstandard2.1, netstandard2.0, net6.0 for reusable protocol implementations
• Legacy industrial PC support: net462 (.NET Framework 4.6.2) for Windows-only OT environments

Sources: README.md22

Conditional Dependency Strategy

The build system supports two development modes controlled by MSBuild property $(SolutionName):

• Monorepo mode (when SolutionName starts with ThingsGatewayAll): Uses <ProjectReference> pointing to ../../../ThingsGateway/... for integrated debugging
• Standalone mode (default): Uses <PackageReference> with versioned NuGet dependencies: ThingsGateway.Gateway.Application version $(GatewayVersion) and ThingsGateway.Foundation version $(FoundationVersion)

This conditional strategy is implemented in Directory.Build.props via MSBuild conditions and enables both core developers (working across multiple repositories) and third-party plugin developers (working on isolated plugins) to use the same project files efficiently.

Sources: Based on high-level architecture diagrams provided in context

NuGet Package Distribution

Package Configuration

Each plugin is distributed as a NuGet package with standardized metadata defined in PackNuget.props:

MSBuild Property	Value/Source
$(PackageId)	ThingsGateway.Plugin.{PluginName} (derived from project name)
$(PackageLicenseExpression)	Apache-2.0
$(PackageProjectUrl)	https://gitee.com/diego2098/ThingsGateway
$(PackageTags)	ThingsGateway;Diego;Blazor;IOT;设备采集;边缘网关;物联网
$(PackageOutputPath)	$(MSBuildThisFileDirectory)..\nupkgs
$(SignAssembly)	True (using ThingsGateway.snk)
$(GenerateDocumentationFile)	True (XML documentation)
$(GeneratePackageOnBuild)	true (automatic packaging)

Sources: PackNuget.props8-29

Package Contents

Each NuGet package includes:

• Compiled assemblies for all target frameworks (net10.0, net8.0, etc.)
• XML documentation files (via <GenerateDocumentationFile>True</GenerateDocumentationFile>)
• Package metadata files: README.md, LICENSE, icon.png, logo.svg (via <None Include=...>)
• Strong-name signature using ThingsGateway.snk (via <AssemblyOriginatorKeyFile>)
• Embedded debug symbols when $(DisableDebugSymbols) != 'true' (via <DebugType>Embedded</DebugType>)

The package output path $(MSBuildThisFileDirectory)..\nupkgs centralizes all plugin packages in a single nupkgs/ directory at the repository root for local testing and distribution.

Additional build-time analyzers are included as development dependencies:

• Roslynator.Analyzers version 4.15.0
• PolySharp version 1.15.0

Sources: PackNuget.props2-6 PackNuget.props10-20 PackNuget.props37-42 PackNuget.props46-54

Key Features and Capabilities

Protocol Support Matrix

The repository contains plugins across multiple protocol categories:

Protocol Category	Plugin Project	Key Implementation Classes	Features
Industrial Protocols	ThingsGateway.Plugin.OpcUa	OpcUaMaster, OpcUaServer	OPC UA client/server, subscription/polling, ThingsGatewayNodeManager
	ThingsGateway.Plugin.OpcDa	OpcDaMaster	OPC DA client (COM-based, Windows only)
	ThingsGateway.Plugin.Modbus	ModbusMaster	Modbus RTU/TCP/ASCII
	ThingsGateway.Plugin.SiemensS7	S7Master	Siemens S7 PLC communication
	ThingsGateway.Plugin.Dlt645	Dlt645Master	DLT645 power meter protocol
Message Brokers	ThingsGateway.Plugin.Mqtt	MqttServer, MqttClient, MqttCollect	MQTT server/client/collector, WebSocket, TLS
	ThingsGateway.Plugin.Kafka	KafkaProducer	Kafka producer, SASL authentication
	ThingsGateway.Plugin.RabbitMQ	RabbitMQProducer	RabbitMQ message publishing
Integration	ThingsGateway.Plugin.Http	HttpWebhookPublisher	HTTP POST webhooks
Persistence	ThingsGateway.Plugin.DB	SqlDBProducer, QuestDBProducer, TDengineDBProducer	Real-time + historical tables, time-series optimization

Sources: ThingsGateway.Plugin.slnx4-14 based on high-level architecture diagrams

Extensibility Mechanisms

1. Dynamic C# Scripts: Database and messaging plugins support runtime-compiled C# scripts via CSharpScriptEngineExtension.Do<DynamicSQLBase>() for custom logic
2. Variable Import: Blazor UI components (OpcUaImportVariable, OpcDaImportVariable) enable browsing external systems and importing variable definitions
3. Historical Data Integration: Database plugins implement IDBHistoryValueService interface, enabling OPC UA Historical Access queries against SQL/TDengine backends
4. Conditional Topic Enablement: Publishing plugins support selective enablement via DevModelEnable, AlarmModelEnable, PluginEventDataModelEnable properties

Debug and Configuration UI

The ThingsGateway.Debug.Razor project provides Blazor components for:

• Protocol-specific address validation (Modbus, Siemens S7, etc.)
• Variable browsing and import from OPC servers
• Real-time debugging of master/slave plugins
• Configuration property editors implementing IPropertyUIBase

Sources: Based on high-level architecture diagrams provided in context

Next Steps

• For build system details: Build System and Configuration
• For architecture patterns: Core Architecture and Design Patterns
• For specific plugin implementations: Data Collection Plugins, Data Publishing and Distribution Plugins, Database Persistence Plugins
• For custom plugin development: Plugin Development Guide