C#实现数据采集系统-数据反写（3）ModbusTcp写入数据模块开发

写入报文分析

ModbusTcp报文详细解析见 ModbusTCP协议报文解析
写入常用的四个功能码，线圈 05,15（0x0F）,寄存器06,16（0x10）

详细报文如下：

//00 01 00 00 00 06 FF 05 00 01 FF 00  写单个线圈
//00 01 00 00 00 06 FF 06 00 05 00 23  写单个寄存器

//写多个寄存器
//00 06 00 00 00 0B FF 10 00 02 00 02 04 00 21 00 2A


//前7位相同，第八位功能码不同，九、十位写入地址，这是格式一样部分

线圈基本都是单个写入，这里就使用05功能码

寄存器写入可能多个同时写入，如int32，float等，需要四个字节，则需要2个寄存器，并且数据的两个寄存器是连续的，，其他的如Int64，double，则需要4个寄存器，我们可以一起写入调高效率。

跟读报文一样，定义一个写入报文的头，前10个报文，再接收到写入数据是再在后面接上对应的数据字段

//读报文
byte[] _writebytes = new byte[]{0x00,0x01,0x00,0x00,0x00,0x06,0xFF,0x01,0x00,0x01};

然后再初始化的时候修改从站地址

写入实现

增加写入功能码关系

public readonly Dictionary<string, byte> WriteFuncCodes = new Dictionary<string, byte>();


        void Init()
        {
            //...

            WriteFuncCodes.Add("Coil", 5);
            WriteFuncCodes.Add("HoldingRegister", 16);
            
            //...

        }

实现写入报文处理方法

定义一个写入方法WriteData用于写入报文发送和返回处理

/// 

/// modbustcp写入方法
/// 
/// 
private void WriteData(RegisterPoint point)
{

}

然后再监控方法中，将等待周期拆分成10份，循环十次等待，每次查询写入队列是否有值，如果有就执行写入

        /// 

        /// 启动主采集线程，循环采集
        /// 
        public void DoMonitor()
        {
            Task.Run(() =>
            {
                //防止重复启动
                if (IsMonitored)
                    return;
                IsMonitored = true;

                while (true)
                {
                    //。。。。原逻辑
                    
                    //循环10次间隔，如果写入队列不为空，则执行写入
                    for (int i = 0; i < 10; i++)
                    {
                        while (_writeQueue.Count > 0)
                        {
                            var point = _writeQueue.Dequeue();
                            WriteData(point);
                        }
                        Task.Delay(_timeSpan).Wait();
                    }
                }
            });
        }
         

写入发送报文处理

修改相同格式的报文部分，功能码和地址

 //修改功能码
  _writebytes[7] = WriteFuncCodes[point.RegisterType];
  //修改写入地址
  var addressBytes = BitConverter.GetBytes(point.Address);
  _writebytes[8] = addressBytes[1];
  _writebytes[9] = addressBytes[0];

然后再根据不同类型功能码处理数据部分

var writebuffer = _writebytes.ToList();
if (point.RegisterType == "Coil")
{
    writebuffer[5] = 0x06;
    if (point.WriteValue.Equals(true))
    {
        writebuffer.Add(0xFF);
    }
    else
    {
        writebuffer.Add(0x00);
    }
    writebuffer.Add(0x00);
}
else if (point.RegisterType == "HoldingRegister")
{
    byte dataLen = (byte)(point.Length * 2);
    writebuffer[5] = Convert.ToByte(7 + dataLen);

    //修改读寄存器数量
    var LengthBytes = BitConverter.GetBytes(point.Length);
    writebuffer.Add(LengthBytes[1]);
    writebuffer.Add(LengthBytes[0]);
    //添加数据长度
    writebuffer.Add(dataLen);

    //转换成字节数组
    var converterMothed = typeof(BitConverter).GetMethod(
        "GetBytes",
        BindingFlags.Public | BindingFlags.Static,
        new[] { point.Type }
    );
    var valueBytes = (byte[])
        converterMothed.Invoke(null, new object[] { point.WriteValue });

    //转字节序
    byte[] newbytes = new byte[point.Length * 2];
    for (int i = 0; i < point.Length; i++)
    {
        newbytes[2 * i] = valueBytes[2 * i + 1];
        newbytes[2 * i + 1] = valueBytes[2 * i];
    }
    writebuffer.AddRange(newbytes);
}

处理完报文就执行发送接收操作

 var client = _tcpClient.Client;
 client.Send(writebuffer.ToArray());

 //接收报文，正常接收说明写入成功
 byte[] recvBytes = Recevice(12, 9);

补充：

接收报文通信过程，跟读报文发送之后的接收报文操作基本一致，同样进行粘包处理，然后异常判断，所以将接收进行封装，只需要传入正常报文长度和异常报文长度，自行

byte[] Recevice(int receiveLen, int errLen)
{
    //接收报文
    byte[] recvBytes = new byte[receiveLen];

    //报文总长
    int recevTotalLength = 0;

    while (recevTotalLength < receiveLen && recevTotalLength != errLen)
    {
        try
        {
            int needLength = receiveLen - recevTotalLength;
            var recvLen = _client.Receive(
                recvBytes,
                recevTotalLength,
                needLength,
                SocketFlags.None
            );
            if (recvLen == 0)
            {
                throw new Exception("未接收到响应数据");
            }
            recevTotalLength += recvLen;
        }
        catch (Exception ex)
        {
            throw new Exception("接收响应数据异常!" + ex.Message);
        }
    }
    if (recvBytes.Length == errLen)
    {
        throw new Exception("返回异常报文");
    }
    return recvBytes;
}

响应报文分析

根据下面不同功能码响应报文可以看出，正常响应报文长度就是12，异常是9，所以前面接收传入的参数就是 Recevice(12, 9)

响应
00 01 00 00 00 06 FF 05 00 01 FF 00 -05
00 01 00 00 00 06 01 0F 00 05 00 0A -15
00 05 00 00 00 06 FF 06 00 05 00 23 -06
00 06 00 00 00 06 FF 10 00 02 00 02 -16

长度12

错误响应
00 01 00 00 00 03 01 8F 02 

长度 9

实现效果

完整代码

  public class ModbusTcp
  {
      /// 

      /// 功能码映射关系
      /// 
      public readonly Dictionary<string, byte> ReadFuncCodes = new Dictionary<string, byte>();
      public readonly Dictionary<string, byte> WriteFuncCodes = new Dictionary<string, byte>();

      //读报文
      byte[] _readbytes = new byte[]
      {
          0x00,
          0x01,
          0x00,
          0x00,
          0x00,
          0x06,
          0xFF,
          0x01,
          0x00,
          0x01,
          0x00,
          0x10
      };

      //写报文（前10位）
      byte[] _writebytes = new byte[]
      {
          0x00,
          0x01,
          0x00,
          0x00,
          0x00,
          0x06,
          0xFF,
          0x01,
          0x00,
          0x01,
      };

      private DeviceLink _link;

      private List<RegisterPoint> _registers;

      private TcpClient _tcpClient;

      private int _timeSpan = 100; // 1000/10 ms  1s==1000ms,然后切成10个片段循环，插空进行写入

      /// 

      /// 连接状态
      /// 
      public bool IsConnected => _tcpClient != null && _tcpClient.Connected;

      private bool IsMonitored = false;

      public event Action<RegisterPoint, object> ValueUpdated;

      /// 

      /// 写入队列
      /// 
      private Queue<RegisterPoint> _writeQueue = new Queue<RegisterPoint>();

      private Socket _client;

      public ModbusTcp(DeviceLink link)
      {
          if (link == null)
          {
              throw new ArgumentNullException("传入配置为空，无法初始化");
          }
          _link = link;
          _timeSpan = (int)(link.AcqTimeSpan * 100);
          _registers = link.Points;
          _tcpClient = new TcpClient();
          Init();
      }

      void Init()
      {
          ReadFuncCodes.Add("Coil", 1);
          ReadFuncCodes.Add("DiscreteInput", 2);
          ReadFuncCodes.Add("HoldingRegister", 3);
          ReadFuncCodes.Add("InputRegister", 4);

          WriteFuncCodes.Add("Coil", 5);
          WriteFuncCodes.Add("HoldingRegister", 16);
          //修改从站地址
          _readbytes[6] = Convert.ToByte(_link.SlaveID);
          _writebytes[6] = Convert.ToByte(_link.SlaveID);
      }

      /// 

      /// 连接
      /// 
      private void Connect()
      {
          try
          {
              _tcpClient.Connect(IPAddress.Parse(_link.Ip), _link.Port);
              _client = _tcpClient.Client;
          }
          catch (Exception ex) { }
      }

      /// 

      /// 启动主采集线程，循环采集
      /// 
      public void DoMonitor()
      {
          Task.Run(() =>
          {
              //防止重复启动
              if (IsMonitored)
                  return;
              IsMonitored = true;

              while (true)
              {
                  if (!_tcpClient.Connected)
                  {
                      Connect();
                  }
                  else
                  {
                      try
                      {
                          foreach (RegisterPoint point in _registers)
                          {
                              SetSendBytes(point);

                              //发送读报文
                              _client.Send(_readbytes);

                              int len = ReceviceDataLength(point.Length);

                              var errLen = 9;
                              var normalLen = 9 + len;
                              //接收报文
                              byte[] recvBytes = Recevice(normalLen, errLen);

                              //提取数据部分
                              byte[] dataBytes = new byte[len];
                              Array.Copy(recvBytes, 9, dataBytes, 0, len);
                              //数据处理
                              DealData(point, dataBytes);
                          }
                      }
                      catch (Exception ex)
                      {
                          Console.WriteLine(ex.Message);
                      }
                  }
                  //循环10次间隔，如果写入队列不为空，则执行写入
                  for (int i = 0; i < 10; i++)
                  {
                      while (_writeQueue.Count > 0)
                      {
                          var point = _writeQueue.Dequeue();
                          WriteData(point);
                      }
                      Task.Delay(_timeSpan).Wait();
                  }
              }
          });
      }

      /// 

      /// 返回报文数据长度
      /// 
      /// 
      /// 
      private int ReceviceDataLength(int pointLength)
      {
          int len;
          if (_readbytes[7] <= 2)
          {
              len = pointLength / 8 + 1;
          }
          else
          {
              len = pointLength * 2;
          }
          return len;
      }

      /// 

      /// 设置查询发送报文
      /// 
      /// 
      private void SetSendBytes(RegisterPoint point)
      {
          //修改功能码
          _readbytes[7] = ReadFuncCodes[point.RegisterType];

          //修改起始地址
          var addressBytes = BitConverter.GetBytes(point.Address);
          _readbytes[8] = addressBytes[1];
          _readbytes[9] = addressBytes[0];

          //修改读寄存器数量
          var LengthBytes = BitConverter.GetBytes(point.Length);
          _readbytes[10] = LengthBytes[1];
          _readbytes[11] = LengthBytes[0];
      }

      /// 

      /// 数据处理方法
      /// 
      /// 
      /// 
      void DealData(RegisterPoint point, byte[] bytes)
      {
          //处理返回数据
          var funcCode = ReadFuncCodes[point.RegisterType];
          object value;

          if (funcCode <= 2)
          {
              //单点查询，线圈只查询一个，byte中不等于0，就是true
              value = bytes[0] != 0;
          }
          else
          {
              if (point.Type == typeof(byte))
              {
                  value = bytes[1];
              }
              else
              {
                  //字节序处理
                  byte[] newbytes = new byte[point.Length * 2];

                  //优化
                  for (int i = 0; i < point.Length; i++)
                  {
                      newbytes[2 * i] = bytes[2 * i + 1];
                      newbytes[2 * i + 1] = bytes[2 * i];
                  }

                  // 优化
                  var converterMothed = typeof(BitConverter).GetMethod(
                      "To" + point.Type.Name,
                      BindingFlags.Public | BindingFlags.Static,
                      new[] { typeof(byte[]), typeof(int) }
                  );
                  value = converterMothed.Invoke(null, new object[] { newbytes, 0 });
              }
          }
          //赋值
          if (!value.Equals(point.Value))
          {
              point.Value = value;
              ValueUpdated?.Invoke(point, value);
          }
      }

      /// 

      /// modbustcp写入方法
      /// 
      /// 
      private void WriteData(RegisterPoint point)
      {
          try
          {
              //00 01 00 00 00 06 FF 05 00 01 FF 00
              //00 05 00 00 00 06 FF 06 00 05 00 23
              //发送长度都一样，格式完全一样
              //前7位相同，第八位功能码不同，九、十位写入地址
              _writebytes[7] = WriteFuncCodes[point.RegisterType];
              //修改写入地址
              var addressBytes = BitConverter.GetBytes(point.Address);
              _writebytes[8] = addressBytes[1];
              _writebytes[9] = addressBytes[0];

              var writebuffer = _writebytes.ToList();
              if (point.RegisterType == "Coil")
              {
                  writebuffer[5] = 0x06;
                  if (point.WriteValue.Equals(true))
                  {
                      writebuffer.Add(0xFF);
                  }
                  else
                  {
                      writebuffer.Add(0x00);
                  }
                  writebuffer.Add(0x00);
              }
              else if (point.RegisterType == "HoldingRegister")
              {
                  byte dataLen = (byte)(point.Length * 2);
                  writebuffer[5] = Convert.ToByte(7 + dataLen);

                  //修改读寄存器数量
                  var LengthBytes = BitConverter.GetBytes(point.Length);
                  writebuffer.Add(LengthBytes[1]);
                  writebuffer.Add(LengthBytes[0]);
                  //添加数据长度
                  writebuffer.Add(dataLen);

                  //转换成字节数组
                  var converterMothed = typeof(BitConverter).GetMethod(
                      "GetBytes",
                      BindingFlags.Public | BindingFlags.Static,
                      new[] { point.Type }
                  );
                  var valueBytes = (byte[])
                      converterMothed.Invoke(null, new object[] { point.WriteValue });

                  //转字节序
                  byte[] newbytes = new byte[point.Length * 2];
                  for (int i = 0; i < point.Length; i++)
                  {
                      newbytes[2 * i] = valueBytes[2 * i + 1];
                      newbytes[2 * i + 1] = valueBytes[2 * i];
                  }
                  writebuffer.AddRange(newbytes);
              }
              var client = _tcpClient.Client;
              client.Send(writebuffer.ToArray());

              //接收报文，正常接收说明写入成功
              byte[] recvBytes = Recevice(12, 9);
          }
          catch (Exception ex)
          {
              Console.WriteLine(ex.Message);
          }
      }

      //写入值先加入一个队列
      public void Write(RegisterPoint point)
      {
          _writeQueue.Enqueue(point);
      }

      byte[] Recevice(int receiveLen, int errLen)
      {
          //接收报文
          byte[] recvBytes = new byte[receiveLen];

          //报文总长
          int recevTotalLength = 0;

          while (recevTotalLength < receiveLen && recevTotalLength != errLen)
          {
              try
              {
                  int needLength = receiveLen - recevTotalLength;
                  var recvLen = _client.Receive(
                      recvBytes,
                      recevTotalLength,
                      needLength,
                      SocketFlags.None
                  );
                  if (recvLen == 0)
                  {
                      throw new Exception("未接收到响应数据");
                  }
                  recevTotalLength += recvLen;
              }
              catch (Exception ex)
              {
                  throw new Exception("接收响应数据异常!" + ex.Message);
              }
          }
          if (recvBytes.Length == errLen)
          {
              throw new Exception("返回异常报文");
          }
          return recvBytes;
      }
  }

源码

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