301 lines
12 KiB
Python
301 lines
12 KiB
Python
#!/usr/bin/env python
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# -*- coding: utf-8 -*-
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"""
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RS485 总线管理器实现
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此模块实现了 IBusManager 接口，用于管理 RS485 总线通信。
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"""
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from ..logs.logger import log
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# 导入 MicroPython 的 UART 和 Pin 库
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from machine import UART, Pin
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import time # 用于添加延时，确保RS485方向切换
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import _thread # 用于线程同步
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import struct # 用于浮点数转换
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class RS485Manager:
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"""
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RS485 总线管理器。
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负责 RS485 设备的指令发送、响应接收和数据解析。
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"""
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def __init__(self, bus_config, default_timeouts):
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"""
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构造函数，注入配置。
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根据传入的配置初始化 RS485 总线对应的 UART 管理器。
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Args:
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bus_config: 包含所有总线配置的字典。
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键是总线ID，值是该总线的详细配置。
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default_timeouts: 包含各种默认超时设置的字典。
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"""
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self.bus_config = bus_config
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self.default_timeouts = default_timeouts
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# 存储以总线号为key的UART管理器实例、RTS引脚和锁
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self.bus_ports = {}
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log("RS485Manager 已使用配置初始化。")
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log(f"总线配置: {self.bus_config}")
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log(f"默认超时设置: {self.default_timeouts}")
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# 遍历 bus_config，初始化 RS485 端口
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for bus_id, config in bus_config.items():
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if config.get('protocol') == 'RS485':
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try:
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uart_id = config['uart_id']
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baudrate = config['baudrate']
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pins = config['pins']
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tx_pin_num = pins['tx']
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rx_pin_num = pins['rx']
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rts_pin_num = pins['rts'] # RS485 的 DE/RE 方向控制引脚
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# 初始化 Pin 对象
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rts_pin = Pin(rts_pin_num, Pin.OUT) # RTS 引脚设置为输出模式
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rts_pin.value(0) # 默认设置为接收模式
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# 初始化 UART 对象
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# 注意：MicroPython 的 UART 构造函数可能不支持直接传入 Pin 对象，而是 Pin 编号
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# 并且 rts 参数通常用于硬件流控制，RS485 的 DE/RE 需要手动控制
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uart = UART(uart_id, baudrate=baudrate, tx=tx_pin_num, rx=rx_pin_num,
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timeout=self.default_timeouts.get('rs485_response', 500))
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self.bus_ports[bus_id] = {
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'uart': uart,
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'rts_pin': rts_pin,
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'lock': _thread.allocate_lock()
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}
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log(f"总线 {bus_id} (RS485) 的 UART 管理器初始化成功。UART ID: {uart_id}, 波特率: {baudrate}, TX: {tx_pin_num}, RX: {rx_pin_num}, RTS(DE/RE): {rts_pin_num}")
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except KeyError as e:
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log(f"错误: 总线 {bus_id} 的 RS485 配置缺少关键参数: {e}")
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except Exception as e:
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log(f"错误: 初始化总线 {bus_id} 的 RS485 管理器失败: {e}")
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else:
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log(f"总线 {bus_id} 的协议不是 RS485，跳过初始化。")
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@staticmethod
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def _calculate_crc16_modbus(data):
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"""
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计算 Modbus RTU 的 CRC16 校验码。
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"""
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crc = 0xFFFF
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for byte in data:
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crc ^= byte
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for _ in range(8):
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if crc & 0x0001:
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crc >>= 1
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crc ^= 0xA001
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else:
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crc >>= 1
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return crc
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def execute_raw_command(self, bus_id, command):
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"""
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【契约】执行一个“发后不理”的原始指令。
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Args:
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bus_id (int): 目标总线的编号。
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command (bytes): 要发送的原始命令字节。
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"""
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if bus_id not in self.bus_ports:
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log(f"错误: 未找到总线 {bus_id} 的 RS485 配置。")
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return
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port_info = self.bus_ports[bus_id]
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uart = port_info['uart']
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rts_pin = port_info['rts_pin']
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lock = port_info['lock']
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with lock:
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try:
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rts_pin.value(1) # 设置为发送模式 (DE/RE = HIGH)
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time.sleep_us(100) # 短暂延时，确保方向切换完成
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uart.write(command)
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# 等待所有数据发送完毕
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uart.flush()
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time.sleep_us(100) # 短暂延时，确保数据完全发出
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rts_pin.value(0) # 切换回接收模式 (DE/RE = LOW)
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log(f"总线 {bus_id} 原始命令发送成功: {command.hex()}")
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except Exception as e:
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log(f"错误: 在总线 {bus_id} 上执行原始命令失败: {e}")
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def execute_collect_task(self, task):
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"""
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【契约】执行一个完整的采集任务，并直接返回最终的数值。
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一个符合本接口的实现必须自己处理所有细节：
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- 从task字典中解析出 bus_id, command, parser_type。
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- 发送指令。
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- 接收响应。
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- 根据parser_type选择正确的内部解析器进行解析。
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- 返回最终的float数值，或在任何失败情况下返回None。
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Args:
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task: 从Protobuf解码出的单个CollectTask消息字典。
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期望结构: {"command": {"bus_number": int, "command_bytes": bytes}}
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Returns:
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成功解析则返回数值，否则返回None。
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"""
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# I. 任务参数解析与初步验证
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try:
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command_info = task.get("command")
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if not command_info:
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log("错误: CollectTask 缺少 'command' 字段。")
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return None
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bus_id = command_info.get("bus_number")
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command_bytes = command_info.get("command_bytes")
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# 增加对命令有效性的检查
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if bus_id is None or not command_bytes or len(command_bytes) < 2:
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log(f"错误: CollectTask 的 'command' 字段无效。bus_id: {bus_id}, command_bytes: {command_bytes}")
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return None
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except Exception as e:
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log(f"错误: 解析CollectTask失败: {e}. 任务: {task}")
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return None
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if bus_id not in self.bus_ports:
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log(f"错误: 未找到总线 {bus_id} 的 RS485 配置。")
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return None
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port_info = self.bus_ports[bus_id]
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uart = port_info['uart']
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rts_pin = port_info['rts_pin']
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lock = port_info['lock']
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response_bytes = None # 在锁外部初始化，确保其作用域
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response_buffer = bytearray()
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with lock:
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try:
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# II. 线程安全与指令发送
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rts_pin.value(1)
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time.sleep_us(100)
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uart.write(command_bytes)
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uart.flush()
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time.sleep_us(100)
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rts_pin.value(0)
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log(f"总线 {bus_id} 原始命令发送成功: {command_bytes.hex()}")
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# III. 接收响应
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start_time = time.ticks_ms()
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response_timeout = self.default_timeouts.get('rs485_response', 500)
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while time.ticks_diff(time.ticks_ms(), start_time) < response_timeout:
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if uart.any():
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chunk = uart.read(32)
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if chunk:
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response_buffer.extend(chunk)
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start_time = time.ticks_ms() # 收到数据就重置超时
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time.sleep_ms(5)
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if response_buffer:
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# 动态地从请求命令中获取预期的从站ID和功能码
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expected_slave_id = command_bytes[0]
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expected_func_code = command_bytes[1]
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found_frame = self._find_modbus_frame(response_buffer, expected_slave_id, expected_func_code)
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if found_frame:
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log(f"总线 {bus_id} 收到有效响应: {found_frame.hex()}")
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response_bytes = found_frame # 将找到的帧赋值给外部变量
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else:
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log(f"警告: 总线 {bus_id} 响应中无有效帧。收到响应: {response_buffer.hex()}")
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else:
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log(f"警告: 总线 {bus_id} 未收到响应。")
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except Exception as e:
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log(f"错误: 在总线 {bus_id} 上执行采集命令失败: {e}")
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# IV. 统一处理和解析
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# 无论是因为超时、未找到有效帧还是发生异常，只要 response_bytes 仍为 None，就任务失败
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if response_bytes is None:
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return None
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# 使用找到的有效帧进行解析
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parsed_value = RS485Manager._parse_modbus_rtu_default(response_bytes)
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return parsed_value
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def _find_modbus_frame(self, buffer: bytearray, expected_slave: int, func_code: int) -> bytes | None:
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"""
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修复版：加调试；优先头检查；CRC 字节序标准 Modbus (低字节在前)。
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"""
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log(f"搜索帧: buffer 长度 {len(buffer)}, hex {buffer.hex()}")
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i = 0
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while i < len(buffer) - 6: # 最小 7 字节，-6 安全
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if buffer[i] == expected_slave and buffer[i + 1] == func_code:
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byte_count = buffer[i + 2]
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frame_len = 3 + byte_count + 2
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if len(buffer) - i >= frame_len:
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frame = bytes(buffer[i:i + frame_len])
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# CRC 预校验（标准 Modbus：CRC 低字节在前）
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core = frame[:-2]
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calc_crc = self._calculate_crc16_modbus(core)
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low_crc = frame[-2]
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high_crc = frame[-1]
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recv_crc = (high_crc << 8) | low_crc # 高<<8 | 低
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log(f"候选帧 at {i}: {frame.hex()}, calc CRC {calc_crc:04X}, recv {recv_crc:04X}")
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if calc_crc == recv_crc:
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log(f"找到有效帧: {frame.hex()}")
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return frame
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else:
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log(f"CRC 不匹配，跳过 (calc {calc_crc:04X} != recv {recv_crc:04X})")
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i += 1
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log("无有效帧")
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return None
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@staticmethod
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def _parse_modbus_rtu_default(response_bytes): # 改名，支持整数/浮点
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"""
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修复版：动态数据长；CRC 只用核心。
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"""
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if not response_bytes or len(response_bytes) < 7:
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log(f"警告: 响应过短。响应: {response_bytes.hex() if response_bytes else 'None'}")
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return None
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# CRC 校验（只核心）
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data_for_crc = response_bytes[:-2]
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received_crc = (response_bytes[-1] << 8) | response_bytes[-2]
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calculated_crc = RS485Manager._calculate_crc16_modbus(data_for_crc)
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if calculated_crc != received_crc:
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log(f"错误: CRC失败。接收: {received_crc:04X}, 计算: {calculated_crc:04X}. 响应: {response_bytes.hex()}")
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return None
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function_code = response_bytes[1]
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byte_count = response_bytes[2]
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data_bytes = response_bytes[3:3 + byte_count]
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if function_code not in [0x03, 0x04]:
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log(f"警告: 功能码 {function_code:02X} 不符。")
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return None
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if len(data_bytes) != byte_count:
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log(f"错误: 数据长 {len(data_bytes)} != {byte_count}")
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return None
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# 动态解析
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if byte_count == 2:
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# 整数 (e.g., 温度)
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try:
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value = int.from_bytes(data_bytes, 'big') # 或 signed '>h'
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parsed_value = value
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log(f"成功解析整数: {parsed_value}")
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return parsed_value
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except Exception as e:
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log(f"整数解析失败: {e}")
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return None
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elif byte_count == 4:
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# 浮点
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try:
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parsed_value = struct.unpack('>f', data_bytes)[0]
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log(f"成功解析浮点: {parsed_value}")
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return parsed_value
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except Exception as e:
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log(f"浮点失败: {e}")
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return None
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else:
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log(f"警告: 未知字节数 {byte_count}")
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return None
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