C#Modbus服务器搭建

private TcpListener tcpListener;

static bool isEnable = false;     //是否加载成功
        static bool isSend = false;   //是否发送成功
        static bool isRead = false;   //是否读取成功

启动服务

public void StartServer()
        {
            if (tcpListener == null)
            {
                tcpListener = new TcpListener(IPAddress.Parse("0.0.0.0"), 9003);
                tcpListener.Start();
                Console.WriteLine("启动服务:9003");
                while (true)
                {
                    TcpClient tcpClient = tcpListener.AcceptTcpClient();
                    System.Threading.Tasks.Task.Factory.StartNew(() => DoListener(tcpClient));
                    Thread.Sleep(100);
                }
            }
        }

打开监听

private void DoListener(TcpClient tcpClient)
        {
            tcpClient.SendTimeout = 30000;
            tcpClient.ReceiveTimeout = 30000;
            //編輯地址
            ushort ad = 14288;
            try
            {
                
                while (true)
                {

                    if (!isEnable)
                    {
                        Console.WriteLine("重置状态中...");
                        InitState(tcpClient.Client, 57357, "00000001");
                        Thread.Sleep(50);
                        continue;
                    }
                    if (!isSend)
                    {
                        Console.WriteLine("写...");
                        List<byte> data = new List<byte>(255);
                        data.Add(Convert.ToByte(24));
                        SendInfo(tcpClient.Client, ad, 85, "00000001", 16, data.ToArray());
                        Thread.Sleep(50);
                        continue;
                    }
                    if (!isRead)
                    {
                        Console.WriteLine("读...");
                        ReadInfo(tcpClient.Client, ad, 85, DataType.Ushort);
                        Thread.Sleep(50);
                        continue;
                    }  
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }

停止监听

public void DisposeServer()
        {
            if (tcpListener != null)
            {
                tcpListener.Stop();
                tcpListener = null;
            }
        }

读取数据

public static object[] ReadInfo(Socket socket, ushort add, short len, DataType type)
        {
            //构建发送报文
            byte[] data = BuidReadMessage(add, len);
            socket.Send(data, data.Length, SocketFlags.None);
            int size = len * 2 + 7;
            byte[] rdata = new byte[size];
            socket.Receive(rdata, size, SocketFlags.None);
            Console.WriteLine("从" + add + "获取数据(" + len + "):" + StringUtils.ByteToHex(rdata));
            //判断是否成功。
            if ((rdata[0] == data[0] && rdata[1] == data[1]))
            {
                isRead = true;
                List<object> listData = new List<object>();
                for (int i = 3; i < rdata[2] + 3;)
                {
                    //listData.Add(BitConverter.ToUInt16(rdata, i));
                    //i += 2;
                    if (type == DataType.Ushort)
                    {
                        listData.Add(BitConverter.ToUInt16(new byte[] { rdata[i + 1], rdata[i] }, 0));
                        i += 2;
                    }
                    else if (type == DataType.Int)
                    {
                        listData.Add(BitConverter.ToInt32(new byte[] { rdata[i + 1], rdata[i], rdata[i + 3], rdata[i + 2] }, 0));
                        i += 4;
                    }
                    else if (type == DataType.Binary)
                    {
                        string strBase1 = Convert.ToString(rdata[i], 2).PadLeft(8, '0');
                        string strBase2 = Convert.ToString(rdata[i + 1], 2).PadLeft(8, '0');
                        listData.Add(ReverseString(strBase2) + ReverseString(strBase1));
                        i += 2;
                    }
                    else if (type == DataType.Bit)
                    {
                        string strBase1 = Convert.ToString(rdata[i], 1);
                        listData.Add(rdata[i]);
                        i += 1;
                    }
                    else
                    {
                        listData.Add(System.Text.Encoding.UTF8.GetString(rdata, 3, rdata[2]));
                        i += rdata[2];
                    }
                }
                return listData.ToArray();
            }
            return new object[0];
        }

写入

 public static void SendInfo(Socket socket, ushort add, short len, string type, short fCode, byte[] toValues)
        {
            byte[] data= BuildSendMessage(add, toValues, len,type,fCode);
            socket.Send(data, data.Length, SocketFlags.None);
            byte[] rdata = new byte[10];
            socket.Receive(rdata, 10, SocketFlags.None);
            //判断是否成功
            if (data[0] == rdata[0] && data[1] == rdata[1])
                isSend = true;
        }

构建读取报文

public static byte[] BuidReadMessage(ushort add,short len)
        {
            byte[] addr = StringUtils.DataConvertToBytes(add);
            byte[] length = StringUtils.DataConvertToBytes(len);
            List<byte> data = new List<byte>(255);

            data.Add(Convert.ToByte(1));                                        
            data.Add(Convert.ToByte(3));     //功能码                                      
            data.AddRange(addr);                   
            data.AddRange(length);                        
            byte[] dataBuff = CRC.ToModbusCRC16Byte(data.ToArray(), true);
            data.AddRange(dataBuff);                          
            return data.ToArray();
        }

构建发送报文

 public static byte[] BuildSendMessage(ushort add, byte[] toValues, short len,string type, short fCode)
        {
            short id = 1;
            List<byte> data = new List<byte>(255);
            data.Add(Convert.ToByte(id));                                             
            data.Add(Convert.ToByte(fCode));                                              
            data.AddRange(StringUtils.DataConvertToBytes(add));                          
            data.AddRange(StringUtils.DataConvertToBytes(len));                         
            data.Add(Convert.ToByte(Math.Ceiling(Convert.ToDecimal(len) / 8)));
            byte[] b = new byte[data.Count+ toValues.Length];
            Array.Copy(data.ToArray(), 0, b, 0, data.Count);
            Array.Copy(toValues, 0, b, data.Count, toValues.Length);
            byte[] dataBuff = new byte[2];
            dataBuff = CRC.ToModbusCRC16Byte(b, true);
            data.AddRange(toValues);   
            data.AddRange(dataBuff);                    
            return data.ToArray();
        }

读取到的数值转换

 private static string ReverseString(string value)
        {
            char[] ch = value.ToArray();//把文本框你的内容转换为char类型数组
            Array.Reverse(ch, 0, value.Length);//使用Array类的Reverse方法颠倒数据
            return new StringBuilder().Append(ch).ToString();//获取指定数组的字符串显示到控件
        }

重置状态

public static void InitState(Socket socket,ushort add,string type)
        {
            try
            {
                byte[] data = BuildSendMessage1(add, type, 1);
                socket.Send(data, data.Length, SocketFlags.None);
                byte[] rdata = new byte[10];
                socket.Receive(rdata, rdata.Length, SocketFlags.None);
                //判断是否成功
                if (rdata[0] == data[0] && rdata[1] == data[1])
                    isEnable = true;
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.ToString());
            }
        }

ModBus和PLC进行交互流程是：通过socket 发送报文，然后接收到返回的结果。

报文格式:

读  路由 功能码 地址 长度  校验码

写  路由 功能码 地址 长度 字节数量 写入的数据 校验码

是读是写依靠功能码去区别。线圈和寄存器的区别，线圈存储的是 0/1，只能存储一个Bool；寄存器可以存储数据

常用的功能码

1　　读取线圈

3　　读取寄存器

5　　写单个寄存器

15　　写线圈

16　　写多个寄存器