> For the complete documentation index, see [llms.txt](https://docs.zongsoft.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zongsoft.com/framework/externals/integration.md).

# OPC UA 设备协议

理解 OPC UA 的节点、会话、订阅与证书，并规划工业设备接入。

OPC UA 为工业设备和应用之间的数据交换提供统一协议。本页介绍节点、会话、订阅与证书等基础概念，以及接入前需要准备的运行条件。

## OPC UA 的基本概念

OPC UA 以服务端地址空间组织设备数据。**NodeId** 标识节点，节点的值还伴随类型、状态码和时间戳；仅显示数值会丢失质量及采样时间信息。

**Session** 是与服务器交互的会话；**Subscription** 及监视项用于持续接收变化。订阅不是永久有效对象，断线重连、服务器重启和证书变更后，都需要验证其恢复状态。

`Zongsoft.Externals.Opc` 提供相关客户端、服务端及读写订阅适配。插件让程序集和 SDK 可用，实际端点、证书信任、会话建立和[工作器](https://github.com/Zongsoft/framework/blob/main/Zongsoft.Core/src/Components/IWorker.cs)生命周期由应用组织。

## 从本地示例开始

先阅读[OPC 示例说明](https://github.com/Zongsoft/framework/blob/main/externals/opc/samples/README.zh-Hans.md)，使用其中配套的本地 server/client 项目。建议依次验证连接、浏览、读取一个已知节点、订阅变化，再验证断线后的恢复。

真实设备写入前还要明确数据类型、量纲、允许范围和设备状态。不能因为 SDK 写入方法返回成功，就忽略设备侧联锁和后续状态确认。

## 证书与身份

应用证书用于建立受信任通信，用户身份决定会话能执行哪些操作，两者不能相互替代。证书主题、应用 URI、有效期及信任目录都应与实际部署一致。

{% hint style="warning" %}
🚨 不要把示例自签名证书、自动信任所有证书或写在命令行中的示例密码作为正式部署方案。私钥和信任目录由运行账号保护；信任变更后应验证客户端与服务器双方的连接行为。
{% endhint %}

诊断至少保留节点标识、质量状态、源时间戳和错误阶段，并控制敏感设备信息的访问。退出时应停止订阅分派、关闭会话并释放客户端，避免重启后残留重复订阅。

源码入口：[OPC](https://github.com/Zongsoft/framework/tree/main/externals/opc)。

## 按项目继续阅读

[Opc](/framework/externals/projects/opc.md)


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