76 lines
3.1 KiB
Python
76 lines
3.1 KiB
Python
# -*- coding: utf-8 -*-
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"""OPC UA 驱动 —— 和利时 DCS 等 OPC UA 接口参数化适配（issue #25 落点）。
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连接参数全部来自模板配置（gateway.yaml 的 drivers.opcua 段），不硬编码。
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实际设备接入依赖第三方库 `asyncua`（异步）或 `opcua`（同步）；
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未安装时给出明确提示，不会静默失败。
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"""
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from __future__ import annotations
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from typing import Dict, List, Optional
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from point_dict.loader import Point
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from .base import Driver, SampleValue
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class OpcUaDriver(Driver):
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"""OPC UA 只读采集驱动（参数化适配）。"""
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protocol = "opcua"
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def __init__(self, config: Optional[dict] = None):
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super().__init__(config)
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self.endpoint: str = self.config.get("endpoint", "")
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self.security: str = self.config.get("security", "None")
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self.username: str = self.config.get("username", "")
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self.password: str = self.config.get("password", "")
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self._client = None
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def connect(self) -> None:
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try:
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from opcua import Client # type: ignore
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except ImportError as exc: # pragma: no cover - 依赖缺失路径
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raise ConnectionError(
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"OPC UA 驱动依赖库未安装：请 `pip install opcua`（或 asyncua）"
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) from exc
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if not self.endpoint:
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raise ConnectionError("OPC UA 驱动缺少配置: drivers.opcua.endpoint")
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self._client = Client(self.endpoint, timeout=self.config.get("timeout", 10))
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# 安全策略参数化（如 Basic256Sha256；证书/密钥由现场安全通道提供）
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if self.security and self.security != "None":
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self._client.set_security_string(self.security)
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# 用户认证参数化（和利时 DCS 的 OPC UA 服务常启用用户名/密码认证）
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if self.username:
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self._client.set_user(self.username)
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self._client.connect()
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if self.username and self.password:
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try:
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self._client.activate_session(self.username, self.password)
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except Exception:
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# 部分服务端在 connect 时已完成认证；激活失败不阻断读取
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pass
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self._client.session_timeout = self.config.get("session_timeout", 60000)
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def read_points(self, points: List[Point]) -> Dict[str, SampleValue]:
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if self._client is None:
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raise ConnectionError("OPC UA 客户端未连接，请先 connect()")
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result: Dict[str, SampleValue] = {}
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for p in points:
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node_path = p.opc_node
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if not node_path:
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continue # 无 OPC 节点的点由其它驱动采集
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try:
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node = self._client.get_node(node_path)
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result[p.point_id] = node.get_value()
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except Exception:
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# 单点读取失败不中断整批：记为未读到（计入丢失率）
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result[p.point_id] = None
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return result
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def close(self) -> None:
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if self._client is not None:
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try:
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self._client.disconnect()
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finally:
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self._client = None
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