Modbus-RTU基本编码的实现

Modbus-RTU基本数据访问包括功能,0x01,0x02，0x03, 0x04, 0x05,0x06,0x0F,0x10，本文介绍Modbus-RTU基本编码的实现。

    namespace TCPClient.Protocol
{
    public class ModbusRTU
    {
        #region Base Read
        /// 

        /// 读输出线圈应用数据单元封装（功能码01）
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] ReadOutputCoilAduRequest(byte address, short startAddress, short coilCount)
        {
            return AduRequest(address, 0x01, startAddress, coilCount);
        }
        /// 

        /// 读输入线圈应用数据单元封装（功能码02）
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] ReadInputCoilAduRequest(byte address, short startAddress, short coilCount)
        {
            return AduRequest(address, 0x02, startAddress, coilCount);
        }
        /// 

        /// 读输出寄存器应用数据单元封装（功能码03）
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] ReadOutputRegisterAduRequest(byte address, short startAddress, short coilCount)
        {
            return AduRequest(address, 0x03, startAddress, coilCount);
        }
        /// 

        /// 读输入寄存器应用数据单元封装（功能码04）
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] ReadInputRegisterAduRequest(byte address, short startAddress, short coilCount)
        {
            return AduRequest(address, 0x04, startAddress, coilCount);
        }
        /// 

        /// 应用数据单元（ADU）封装
        /// 
        /// 
        /// 
        /// 
        private static byte[] AduRequest(byte address,byte functionCode, short startAddress, short coilCount)
        {
            
            List<byte> list= ReadCoil(functionCode, startAddress, coilCount);
            byte[] res = new byte[list.Count+3];
            res[0] = address;
            list.ToArray().CopyTo(res, 1);
            byte[] crc = CRC16(res, (ushort)(list.Count + 1));
            res[list.Count + 1] = crc[1];
            res[list.Count + 2] = crc[0];
            return res;
        }
        /// 

        /// 读线圈协议数据单元封装（功能码01,02,03,04）
        /// 
        /// 
        /// 
        /// 
        /// 
        private static List<byte> ReadCoil(byte functionCode,short startAddress,short coilCount)
        {
            List<byte> res=new List<byte>();
            res.Add(functionCode);
            res.Add(BitConverter.GetBytes(startAddress)[1]);
            res.Add(BitConverter.GetBytes(startAddress)[0]);
            res.Add(BitConverter.GetBytes(coilCount)[1]);
            res.Add(BitConverter.GetBytes(coilCount)[0]);
            return res;
        }
        #endregion

        #region Base Write
        /// 

        /// 写单个线圈（05）
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] WriteSingleCoilAduRequest(byte address, short outputAddress, short value)
        {
            return AduRequest(address, 0x05, outputAddress, value);
        }
        /// 

        /// 写单个寄存器（06）
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] WriteSingleRegisterAduRequest(byte address, short outputAddress, short value)
        {
            return AduRequest(address, 0x06, outputAddress, value);
        }
        /// 

        /// 写多个线圈（0F）
        /// 
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] WriteMutiCoilAduRequest(byte address, short outputAddress, short outputCount, byte[] value)
        {
            return AduWriteRequest(address, 0x0F, outputAddress, outputCount, value);
        }
        /// 

        /// 写多个寄存器(10)
        /// 
        /// 
        /// 
        /// 
        /// 
        /// 
        public static byte[] WriteMutiRegisterAduRequest(byte address, short outputAddress, short outputCount, byte[] value)
        {
            return AduWriteRequest(address, 0x10, outputAddress, outputCount, value);
        }
        /// 

        /// 写请求ADU打包
        /// 
        /// 
        /// 
        /// 
        /// 
        /// 
        /// 
        private static byte[] AduWriteRequest(byte address, byte functionCode, short startAddress, short outputCount, byte[] value)
        {
            List<byte> list = null;
            if (functionCode == 0x0F)
            {
                list = WriteMutiCoil(functionCode, startAddress, outputCount, value);
            }else if(functionCode == 0x10)
            {
                list = WriteMutiRegister(functionCode, startAddress, outputCount, value);
            }
            else
            {
                return null;
            } 
            byte[] res = new byte[list.Count + 3];
            res[0] = address;
            list.ToArray().CopyTo(res, 1);
            byte[] crc = CRC16(res, (ushort)(list.Count + 1));
            res[list.Count + 1] = crc[1];
            res[list.Count + 2] = crc[0];
            return res;
        }
        /// 

        /// 写多个线圈PDU(0x0F)
        /// 
        /// 功能码
        /// 起始地址
        /// 输出数量
        /// 输出值数组（outputCount/8或加1）
        /// 
        private static List<byte> WriteMutiCoil(byte functionCode, short startAddress, short outputCount, byte[] value)
        {
            byte byteCount = (byte)(outputCount / 8);
            if (outputCount % 8 != 0)
            {
                byteCount += 1;
            }
            if(value.Length!= byteCount)
            {
                return null;
            }
            List<byte> res = new List<byte>();
            res.Add(functionCode);
            res.Add(BitConverter.GetBytes(startAddress)[1]);
            res.Add(BitConverter.GetBytes(startAddress)[0]);
            res.Add(BitConverter.GetBytes(outputCount)[1]);
            res.Add(BitConverter.GetBytes(outputCount)[0]);
            res.Add(byteCount);
            foreach (byte b in value)
            {
                res.Add(b);
            }
            return res;
        }
        /// 

        /// 写多个寄存器PDU（0x10）
        /// 
        /// 功能码
        /// 起始地址
        /// 寄存器数量
        /// 寄存器值数组（2*outputCount）
        /// 
        private static List<byte> WriteMutiRegister(byte functionCode, short startAddress, short outputCount, byte[] value)
        {
            byte byteCount = (byte)(outputCount*2);
            if (value.Length != byteCount)
            {
                return null;
            }
            List<byte> res = new List<byte>();
            res.Add(functionCode);
            res.Add(BitConverter.GetBytes(startAddress)[1]);
            res.Add(BitConverter.GetBytes(startAddress)[0]);
            res.Add(BitConverter.GetBytes(outputCount)[1]);
            res.Add(BitConverter.GetBytes(outputCount)[0]);
            res.Add(byteCount);
            foreach (byte b in value)
            {
                res.Add(b);
            }
            return res;
        }
        #endregion

        #region CRC16
        /// 

        /// CRC16校验
        /// 
        /// 
        /// 
        /// 
        private static byte[] CRC16(byte[] data,ushort length)
        {
            int i = 0;
            byte[] res= new byte[2];
            res[1] = 0xFF;
            res[0] = 0xFF;
            int index=0;
            while (length-->0)
            {
                index = res[0] ^ data[i++];
                res[0] = (byte)(res[1] ^ auchCRCHi[index]);
                res[1] = auchCRCLo[index];
            }
            return res;
        }
        /// 

        /// 校验高字节数据表
        /// 
        static byte[] auchCRCHi = {
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
            0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01,
            0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41,
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81,
            0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0,
            0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01,
            0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40,
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
            0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01,
            0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
            0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0,
            0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01,
            0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81, 0x40, 0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41,
            0x00, 0xC1, 0x81, 0x40, 0x01, 0xC0, 0x80, 0x41, 0x01, 0xC0, 0x80, 0x41, 0x00, 0xC1, 0x81,
            0x40
        };
        /// 

        /// 校验低字节数据表
        /// 
        static byte[] auchCRCLo = {
            0x00, 0xC0, 0xC1, 0x01, 0xC3, 0x03, 0x02, 0xC2, 0xC6, 0x06, 0x07, 0xC7, 0x05, 0xC5, 0xC4,
            0x04, 0xCC, 0x0C, 0x0D, 0xCD, 0x0F, 0xCF, 0xCE, 0x0E, 0x0A, 0xCA, 0xCB, 0x0B, 0xC9, 0x09,
            0x08, 0xC8, 0xD8, 0x18, 0x19, 0xD9, 0x1B, 0xDB, 0xDA, 0x1A, 0x1E, 0xDE, 0xDF, 0x1F, 0xDD,
            0x1D, 0x1C, 0xDC, 0x14, 0xD4, 0xD5, 0x15, 0xD7, 0x17, 0x16, 0xD6, 0xD2, 0x12, 0x13, 0xD3,
            0x11, 0xD1, 0xD0, 0x10, 0xF0, 0x30, 0x31, 0xF1, 0x33, 0xF3, 0xF2, 0x32, 0x36, 0xF6, 0xF7,
            0x37, 0xF5, 0x35, 0x34, 0xF4, 0x3C, 0xFC, 0xFD, 0x3D, 0xFF, 0x3F, 0x3E, 0xFE, 0xFA, 0x3A,
            0x3B, 0xFB, 0x39, 0xF9, 0xF8, 0x38, 0x28, 0xE8, 0xE9, 0x29, 0xEB, 0x2B, 0x2A, 0xEA, 0xEE,
            0x2E, 0x2F, 0xEF, 0x2D, 0xED, 0xEC, 0x2C, 0xE4, 0x24, 0x25, 0xE5, 0x27, 0xE7, 0xE6, 0x26,
            0x22, 0xE2, 0xE3, 0x23, 0xE1, 0x21, 0x20, 0xE0, 0xA0, 0x60, 0x61, 0xA1, 0x63, 0xA3, 0xA2,
            0x62, 0x66, 0xA6, 0xA7, 0x67, 0xA5, 0x65, 0x64, 0xA4, 0x6C, 0xAC, 0xAD, 0x6D, 0xAF, 0x6F,
            0x6E, 0xAE, 0xAA, 0x6A, 0x6B, 0xAB, 0x69, 0xA9, 0xA8, 0x68, 0x78, 0xB8, 0xB9, 0x79, 0xBB,
            0x7B, 0x7A, 0xBA, 0xBE, 0x7E, 0x7F, 0xBF, 0x7D, 0xBD, 0xBC, 0x7C, 0xB4, 0x74, 0x75, 0xB5,
            0x77, 0xB7, 0xB6, 0x76, 0x72, 0xB2, 0xB3, 0x73, 0xB1, 0x71, 0x70, 0xB0, 0x50, 0x90, 0x91,
            0x51, 0x93, 0x53, 0x52, 0x92, 0x96, 0x56, 0x57, 0x97, 0x55, 0x95, 0x94, 0x54, 0x9C, 0x5C,
            0x5D, 0x9D, 0x5F, 0x9F, 0x9E, 0x5E, 0x5A, 0x9A, 0x9B, 0x5B, 0x99, 0x59, 0x58, 0x98, 0x88,
            0x48, 0x49, 0x89, 0x4B, 0x8B, 0x8A, 0x4A, 0x4E, 0x8E, 0x8F, 0x4F, 0x8D, 0x4D, 0x4C, 0x8C,
            0x44, 0x84, 0x85, 0x45, 0x87, 0x47, 0x46, 0x86, 0x82, 0x42, 0x43, 0x83, 0x41, 0x81, 0x80,
            0x40
         };
        #endregion
    }
}