import serial
import time
import struct


class InovanceMD520:
    def __init__(self, port='COM4', baudrate=9600, timeout=1):
        """
        初始化汇川MD520变频器通信
        :param port: 串口名称，Windows为COMx，Linux为/dev/ttyUSBx
        :param baudrate: 波特率，默认9600
        :param timeout: 超时时间，秒
        """
        self.port = port
        self.baudrate = baudrate
        self.timeout = timeout
        self.ser = None

    def connect(self):
        """连接串口"""
        try:
            self.ser = serial.Serial(
                port=self.port,
                baudrate=self.baudrate,
                bytesize=serial.EIGHTBITS,
                parity=serial.PARITY_NONE,
                stopbits=serial.STOPBITS_ONE,
                timeout=self.timeout
            )
            print(f"成功连接到串口 {self.port}")
            return True
        except serial.SerialException as e:
            print(f"连接串口失败: {e}")
            return False

    def disconnect(self):
        """断开串口连接"""
        if self.ser and self.ser.is_open:
            self.ser.close()
            print("串口连接已关闭")

    def calculate_crc(self, data):
        """
        计算Modbus CRC16校验码
        :param data: 字节数据
        :return: CRC校验码（低位在前，高位在后）
        """
        crc = 0xFFFF
        for byte in data:
            crc ^= byte
            for _ in range(8):
                if crc & 0x0001:
                    crc = (crc >> 1) ^ 0xA001
                else:
                    crc = crc >> 1
        return struct.pack('<H', crc)  # 小端序，低位在前

    def query_frequency(self, slave_addr=0x01):
        """
        查询变频器运行频率
        :param slave_addr: 从站地址，默认1
        :return: 频率值（Hz），如查询失败返回None
        """
        if not self.ser or not self.ser.is_open:
            print("串口未连接")
            return None

        # 构建查询指令：读取运行频率（地址1001H）
        # 01 03 10 01 00 01
        cmd_data = bytes([
            slave_addr,  # 从站地址
            0x03,  # 功能码：读取保持寄存器
            0x10, 0x01,  # 寄存器地址：1001H（运行频率）
            0x00, 0x01  # 读取1个寄存器
        ])

        # 计算CRC
        crc = self.calculate_crc(cmd_data)

        # 完整指令
        full_cmd = cmd_data + crc

        print(f"发送查询指令: {full_cmd.hex().upper()}")

        try:
            # 清空输入缓冲区
            self.ser.reset_input_buffer()

            # 发送指令
            self.ser.write(full_cmd)

            # 等待响应（根据文档需要等待3.5个字节时间）
            time.sleep(0.01)  # 约10ms延迟

            # 读取响应
            # 正常响应格式：地址(1) + 功能码(1) + 字节数(1) + 数据(2) + CRC(2) = 7字节
            response = self.ser.read(7)

            if len(response) < 7:
                print(f"响应数据长度不足: {len(response)} 字节")
                return None

            print(f"收到响应: {response.hex().upper()}")

            # 验证响应
            if response[0] != slave_addr:
                print(f"从站地址不匹配: 期望{slave_addr:02X}, 收到{response[0]:02X}")
                return None

            if response[1] != 0x03:
                print(f"功能码错误: 期望03, 收到{response[1]:02X}")
                return None

            if response[2] != 0x02:
                print(f"数据长度错误: 期望02, 收到{response[2]:02X}")
                return None

            # 验证CRC
            received_crc = response[-2:]
            calculated_crc = self.calculate_crc(response[:-2])
            if received_crc != calculated_crc:
                print("CRC校验失败")
                return None

            # 解析频率数据（高字节在前）
            frequency_raw = (response[3] << 8) | response[4]
            frequency_hz = frequency_raw / 100.0  # 转换为Hz（单位0.01Hz）

            print(f"原始频率值: {frequency_raw} (0x{frequency_raw:04X})")
            print(f"实际频率: {frequency_hz:.2f} Hz")

            return frequency_hz

        except Exception as e:
            print(f"通信错误: {e}")
            return None

    def set_frequency(self, slave_addr=0x01,frequency=210):
        """
        变频器运行频率
        :param slave_addr: 从站地址，默认1
        :return: 频率值（Hz），如查询失败返回None
        """
        if not self.ser or not self.ser.is_open:
            print("串口未连接")
            return None

        # 构建查询指令：读取运行频率（地址1001H）
        # 01 03 10 01 00 01
        cmd_data = bytes([
            slave_addr,  # 从站地址
            0x06,  # 功能码：读取保持寄存器
            0x10, 0x00,  # 寄存器地址：1001H（运行频率）
            0x1B, 0x58  # 读取1个寄存器
        ])

        # 计算CRC
        crc = self.calculate_crc(cmd_data)

        # 完整指令
        full_cmd = cmd_data + crc

        print(f"发送查询指令: {full_cmd.hex().upper()}")

        try:
            # 清空输入缓冲区
            self.ser.reset_input_buffer()

            # 发送指令
            self.ser.write(full_cmd)

            # 等待响应（根据文档需要等待3.5个字节时间）
            time.sleep(0.01)  # 约10ms延迟

            # 读取响应
            # 正常响应格式：地址(1) + 功能码(1) + 字节数(1) + 数据(2) + CRC(2) = 7字节
            response = self.ser.read(7)

            if len(response) < 7:
                print(f"响应数据长度不足: {len(response)} 字节")
                return None

            print(f"收到响应: {response.hex().upper()}")

            # 验证响应
            if response[0] != slave_addr:
                print(f"从站地址不匹配: 期望{slave_addr:02X}, 收到{response[0]:02X}")
                return None

            if response[1] != 0x06:
                print(f"功能码错误: 期望03, 收到{response[1]:02X}")
                return None

            # 验证CRC
            received_crc = response[-2:]
            calculated_crc = self.calculate_crc(response[:-2])
            if received_crc != calculated_crc:
                print("CRC校验失败")
                return None

            return True

        except Exception as e:
            print(f"通信错误: {e}")
            return None



    def read_register(self, slave_addr, register_addr, register_count=1):
        """
        通用读取寄存器方法
        :param slave_addr: 从站地址
        :param register_addr: 寄存器地址（16位）
        :param register_count: 读取的寄存器数量
        :return: 读取的数据列表
        """
        if not self.ser or not self.ser.is_open:
            print("串口未连接")
            return None

        # 构建读取指令
        cmd_data = bytes([
            slave_addr,  # 从站地址
            0x03,  # 功能码：读取保持寄存器
            (register_addr >> 8) & 0xFF,  # 寄存器地址高字节
            register_addr & 0xFF,  # 寄存器地址低字节
            (register_count >> 8) & 0xFF,  # 寄存器数量高字节
            register_count & 0xFF  # 寄存器数量低字节
        ])

        # 计算CRC
        crc = self.calculate_crc(cmd_data)
        full_cmd = cmd_data + crc

        print(f"发送读取指令: {full_cmd.hex().upper()}")

        try:
            self.ser.reset_input_buffer()
            self.ser.write(full_cmd)
            time.sleep(0.01)

            # 计算预期响应长度
            expected_length = 5 + 2 * register_count  # 地址1 + 功能码1 + 字节数1 + 数据2*N + CRC2
            response = self.ser.read(expected_length)

            if len(response) < expected_length:
                print(f"响应数据长度不足: {len(response)} 字节，期望 {expected_length} 字节")
                return None

            print(f"收到响应: {response.hex().upper()}")

            # 验证CRC
            received_crc = response[-2:]
            calculated_crc = self.calculate_crc(response[:-2])
            if received_crc != calculated_crc:
                print("CRC校验失败")
                return None

            # 解析数据
            data_length = response[2]
            data_bytes = response[3:3 + data_length]

            results = []
            for i in range(0, len(data_bytes), 2):
                value = (data_bytes[i] << 8) | data_bytes[i + 1]
                results.append(value)

            return results

        except Exception as e:
            print(f"通信错误: {e}")
            return None


def main():
    # 创建变频器对象
    inverter = InovanceMD520(port='COM3', baudrate=9600)

    # 连接串口
    if not inverter.connect():
        return

    try:
        while True:
            print("\n" + "=" * 50)
            print("汇川MD520变频器频率查询")
            print("=" * 50)

            # 设置允许频率
            frequency = inverter.set_frequency(slave_addr=0x01, frequency=210.0)
            if frequency is not None:
                print(f"✅ 设置成功")
            else:
                print("❌ 频率设置失败")

            # 查询运行频率
            frequency = inverter.query_frequency(slave_addr=0x01)

            if frequency is not None:
                print(f"✅ 当前运行频率: {frequency:.2f} Hz")
            else:
                print("❌ 频率查询失败")



            # 可选：读取其他监控参数
            print("\n--- 其他监控参数 ---")

            # 读取母线电压 (地址1002H)
            voltage_data = inverter.read_register(0x01, 0x1002)
            if voltage_data:
                voltage = voltage_data[0] / 10.0  # 单位0.1V
                print(f"母线电压: {voltage:.1f} V")

            # 读取输出电压 (地址1003H)
            output_voltage_data = inverter.read_register(0x01, 0x1003)
            if output_voltage_data:
                output_voltage = output_voltage_data[0]  # 单位1V
                print(f"输出电压: {output_voltage} V")

            # 读取输出电流 (地址1004H)
            current_data = inverter.read_register(0x01, 0x1004)
            if current_data:
                current = current_data[0] / 100.0  # 单位0.01A
                print(f"输出电流: {current:.2f} A")

            # 等待5秒后再次查询
            print("\n等待5秒后继续查询...")
            time.sleep(5)

    except KeyboardInterrupt:
        print("\n用户中断查询")
    finally:
        # 断开连接
        inverter.disconnect()


if __name__ == "__main__":
    main()