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iAOP/core/edge-gateway/drivers/s7_driver.py
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# -*- coding: utf-8 -*-
"""西门子 S7-1200 驱动 —— 参数化适配(issue #24 落点)。
连接参数(ip / rack / slot / db / offset 映射)全部来自模板配置,
点位到 DB 地址的映射通过点位字典 CSV 的 opcNode 列携带
(S7 场景下约定格式 `DB{db}.{byte}.{bit}`,如 DB100.0.0)。
依赖 `python-snap7`,未安装时给出明确提示。
"""
from __future__ import annotations
import re
from typing import Dict, List, Optional
from point_dict.loader import Point
from .base import Driver, SampleValue
_S7_NODE_RE = re.compile(r"^DB(\d+)\.(\d+)(?:\.(\d+))?$")
class S7Driver(Driver):
"""西门子 S7-1200 只读采集驱动(参数化适配)。"""
protocol = "s7"
def __init__(self, config: Optional[dict] = None):
super().__init__(config)
self.ip: str = self.config.get("ip", "")
self.rack: int = int(self.config.get("rack", 0))
self.slot: int = int(self.config.get("slot", 1))
self._client = None
def connect(self) -> None:
try:
import snap7 # type: ignore
except ImportError as exc: # pragma: no cover - 依赖缺失路径
raise ConnectionError(
"S7 驱动依赖库未安装:请 `pip install python-snap7`"
) from exc
if not self.ip:
raise ConnectionError("S7 驱动缺少配置: drivers.s7.ip")
self._client = snap7.client.Client()
self._client.connect(self.ip, self.rack, self.slot)
def read_points(self, points: List[Point]) -> Dict[str, SampleValue]:
if self._client is None:
raise ConnectionError("S7 客户端未连接,请先 connect()")
result: Dict[str, SampleValue] = {}
for p in points:
match = _S7_NODE_RE.match(p.opc_node or "")
if not match:
continue # 非 S7 点位由其它驱动采集
db, byte_, bit = int(match.group(1)), int(match.group(2)), match.group(3)
try:
if bit is not None:
result[p.point_id] = self._client.read_area(
0x84, db, byte_ * 8 + int(bit), 1
)[0]
else:
result[p.point_id] = self._client.read_area(0x84, db, byte_, 4)[0]
except Exception:
result[p.point_id] = None # 单点失败不中断整批
return result
def close(self) -> None:
if self._client is not None:
try:
self._client.disconnect()
finally:
self._client = None