private void AcceptCallback(IAsyncResult ar)
{
m_clientSocket = null;
try
{
AcceptStateObject stateObj = (AcceptStateObject)ar.AsyncState;
m_clientSocket = stateObj.ServerSocket.EndAccept(ar);
}
catch (Exception ex)
{
}
finally
{
m_timeoutObject.Set();
}
}
/// <summary>
/// 请求Modbus RTU 数据，发生错误会抛出异常
/// </summary>
/// <param name="devAddr">设备地址</param>
/// <param name="funcCode">功能代码</param>
/// <param name="startAddr">起始地址</param>
/// <param name="regCount">读取寄存器数</param>
/// <returns>请求结果数据内容</returns>
public string RequestModbusRTUData(byte devAddr, byte funcCode,
ushort startAddr, ushort regCount)
{
string mbRtuData = string.Empty;
Socket serverSocket = null;
try
{
try
{
ushort port = 6008;
IPAddress address = IPAddress.Parse("172.16.1.2");
IPEndPoint endPoint = new IPEndPoint(address, port);
serverSocket = new Socket(AddressFamily.InterNetwork,
SocketType.Stream,
ProtocolType.Tcp);
serverSocket.Bind(endPoint);
serverSocket.Listen(10);
}
catch (Exception e)
{
throw new Exception(e.Message);
}
m_timeoutObject.Reset();
AcceptStateObject stateObj = new AcceptStateObject();
stateObj.ServerSocket = serverSocket;
serverSocket.BeginAccept(new AsyncCallback(AcceptCallback), stateObj);
if (m_timeoutObject.WaitOne(1000, false) && m_clientSocket != null)
{
//m_clientSocket = serverSocket.Accept();
if (m_clientSocket != null)
{
byte[] temp = new byte[6];
temp[0] = devAddr;
temp[1] = funcCode;
byte[] bStartAddr = BitConverter.GetBytes(startAddr);
temp[2] = bStartAddr[1];
temp[3] = bStartAddr[0];
byte[] bRegCount = BitConverter.GetBytes(regCount);
temp[4] = bRegCount[1];
temp[5] = bRegCount[0];
uint iCRC16 = ModbusCRC16(temp, temp.Length);
byte[] bCrc16 = BitConverter.GetBytes(iCRC16);
byte[] modbusRtuReq = new byte[8];
modbusRtuReq[0] = temp[0];
modbusRtuReq[1] = temp[1];
modbusRtuReq[2] = temp[2];
modbusRtuReq[3] = temp[3];
modbusRtuReq[4] = temp[4];
modbusRtuReq[5] = temp[5];
//CRC16 低位在前，高位在后
modbusRtuReq[6] = bCrc16[0];
modbusRtuReq[7] = bCrc16[1];
m_clientSocket.Send(modbusRtuReq);
Thread.Sleep(500);
byte[] modbusRtuResponse = new byte[5 + regCount * 2];
try
{
m_clientSocket.Receive(modbusRtuResponse, modbusRtuResponse.Length, SocketFlags.None);
mbRtuData = BitConverter.ToString(modbusRtuResponse);
}
catch (Exception ex)
{
throw new Exception(ex.Message);
}
m_clientSocket.Close();
}
}
else
{
throw new Exception("未与数据源建立连接");
}
}
finally
{
serverSocket.Close();
serverSocket = null;
}
return(mbRtuData);
}
