diff --git a/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiInTcpProtocol.cs b/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiInTcpProtocol.cs
index b365e52..8a9f9ee 100644
--- a/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiInTcpProtocol.cs
+++ b/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiInTcpProtocol.cs
@@ -12,9 +12,8 @@ namespace Modbus.Net.Modbus
         /// </summary>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusAsciiInTcpProtocol(byte slaveAddress, byte masterAddress, Endian endian)
-            : this(ConfigurationManager.AppSettings["IP"], slaveAddress, masterAddress, endian)
+        public ModbusAsciiInTcpProtocal(byte slaveAddress, byte masterAddress)
+            : this(ConfigurationManager.AppSettings["IP"], slaveAddress, masterAddress)
         {
         }
 
@@ -24,9 +23,8 @@ namespace Modbus.Net.Modbus
         /// <param name="ip">ip地址</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusAsciiInTcpProtocol(string ip, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusAsciiInTcpProtocal(string ip, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusAsciiInTcpProtocolLinker(ip, slaveAddress);
         }
@@ -38,9 +36,8 @@ namespace Modbus.Net.Modbus
         /// <param name="port">端口</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusAsciiInTcpProtocol(string ip, int port, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusAsciiInTcpProtocal(string ip, int port, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusTcpProtocolLinker(ip, port);
         }
diff --git a/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiProtocol.cs b/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiProtocol.cs
index 18d5fff..f3a4408 100644
--- a/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiProtocol.cs
+++ b/Modbus.Net/Modbus.Net.Modbus/ModbusAsciiProtocol.cs
@@ -12,9 +12,8 @@ namespace Modbus.Net.Modbus
         /// </summary>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusAsciiProtocol(byte slaveAddress, byte masterAddress, Endian endian)
-            : this(ConfigurationManager.AppSettings["COM"], slaveAddress, masterAddress, endian)
+        public ModbusAsciiProtocal(byte slaveAddress, byte masterAddress)
+            : this(ConfigurationManager.AppSettings["COM"], slaveAddress, masterAddress)
         {
         }
 
@@ -24,9 +23,8 @@ namespace Modbus.Net.Modbus
         /// <param name="com">串口地址</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusAsciiProtocol(string com, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusAsciiProtocal(string com, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusAsciiProtocolLinker(com, slaveAddress);
         }
diff --git a/Modbus.Net/Modbus.Net.Modbus/ModbusProtocol.cs b/Modbus.Net/Modbus.Net.Modbus/ModbusProtocol.cs
index 0a52249..0bae45e 100644
--- a/Modbus.Net/Modbus.Net.Modbus/ModbusProtocol.cs
+++ b/Modbus.Net/Modbus.Net.Modbus/ModbusProtocol.cs
@@ -98,9 +98,8 @@ namespace Modbus.Net.Modbus
         /// </summary>
         /// <param name="slaveAddress">从站地址</param>
         /// <param name="masterAddress">主站地址</param>
-        /// <param name="endian">端格式</param>
-        protected ModbusProtocol(byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        protected ModbusProtocal(byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress, Endian.BigEndianLsb)
         {
         }
 
diff --git a/Modbus.Net/Modbus.Net.Modbus/ModbusRtuInTcpProtocol.cs b/Modbus.Net/Modbus.Net.Modbus/ModbusRtuInTcpProtocol.cs
index e5d8102..dd7c023 100644
--- a/Modbus.Net/Modbus.Net.Modbus/ModbusRtuInTcpProtocol.cs
+++ b/Modbus.Net/Modbus.Net.Modbus/ModbusRtuInTcpProtocol.cs
@@ -13,9 +13,8 @@ namespace Modbus.Net.Modbus
         /// </summary>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusRtuInTcpProtocol(byte slaveAddress, byte masterAddress, Endian endian)
-            : this(ConfigurationManager.AppSettings["IP"], slaveAddress, masterAddress, endian)
+        public ModbusRtuInTcpProtocal(byte slaveAddress, byte masterAddress)
+            : this(ConfigurationManager.AppSettings["IP"], slaveAddress, masterAddress)
         {
         }
 
@@ -25,9 +24,8 @@ namespace Modbus.Net.Modbus
         /// <param name="ip">ip地址</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusRtuInTcpProtocol(string ip, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusRtuInTcpProtocal(string ip, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusTcpProtocolLinker(ip);
         }
@@ -39,9 +37,8 @@ namespace Modbus.Net.Modbus
         /// <param name="port">端口号</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusRtuInTcpProtocol(string ip, int port, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusRtuInTcpProtocal(string ip, int port, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusRtuInTcpProtocolLinker(ip, port);
         }
diff --git a/Modbus.Net/Modbus.Net.Modbus/ModbusRtuProtocol.cs b/Modbus.Net/Modbus.Net.Modbus/ModbusRtuProtocol.cs
index 6227e43..88035bc 100644
--- a/Modbus.Net/Modbus.Net.Modbus/ModbusRtuProtocol.cs
+++ b/Modbus.Net/Modbus.Net.Modbus/ModbusRtuProtocol.cs
@@ -12,9 +12,8 @@ namespace Modbus.Net.Modbus
         /// </summary>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusRtuProtocol(byte slaveAddress, byte masterAddress, Endian endian)
-            : this(ConfigurationManager.AppSettings["COM"], slaveAddress, masterAddress, endian)
+        public ModbusRtuProtocal(byte slaveAddress, byte masterAddress)
+            : this(ConfigurationManager.AppSettings["COM"], slaveAddress, masterAddress)
         {
         }
 
@@ -24,9 +23,8 @@ namespace Modbus.Net.Modbus
         /// <param name="com">串口</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusRtuProtocol(string com, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusRtuProtocal(string com, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusRtuProtocolLinker(com, slaveAddress);
         }
diff --git a/Modbus.Net/Modbus.Net.Modbus/ModbusTcpProtocol.cs b/Modbus.Net/Modbus.Net.Modbus/ModbusTcpProtocol.cs
index 0ae1ce1..d859433 100644
--- a/Modbus.Net/Modbus.Net.Modbus/ModbusTcpProtocol.cs
+++ b/Modbus.Net/Modbus.Net.Modbus/ModbusTcpProtocol.cs
@@ -12,9 +12,8 @@ namespace Modbus.Net.Modbus
         /// </summary>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusTcpProtocol(byte slaveAddress, byte masterAddress, Endian endian)
-            : this(ConfigurationManager.AppSettings["IP"], slaveAddress, masterAddress, endian)
+        public ModbusTcpProtocal(byte slaveAddress, byte masterAddress)
+            : this(ConfigurationManager.AppSettings["IP"], slaveAddress, masterAddress)
         {
         }
 
@@ -24,9 +23,8 @@ namespace Modbus.Net.Modbus
         /// <param name="ip">ip地址</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusTcpProtocol(string ip, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusTcpProtocal(string ip, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusTcpProtocolLinker(ip);
         }
@@ -38,9 +36,8 @@ namespace Modbus.Net.Modbus
         /// <param name="port">端口</param>
         /// <param name="slaveAddress">从站号</param>
         /// <param name="masterAddress">主站号</param>
-        /// <param name="endian">端格式</param>
-        public ModbusTcpProtocol(string ip, int port, byte slaveAddress, byte masterAddress, Endian endian)
-            : base(slaveAddress, masterAddress, endian)
+        public ModbusTcpProtocal(string ip, int port, byte slaveAddress, byte masterAddress)
+            : base(slaveAddress, masterAddress)
         {
             ProtocolLinker = new ModbusTcpProtocolLinker(ip, port);
         }
diff --git a/Modbus.Net/Modbus.Net.Modbus/ModbusUtility.cs b/Modbus.Net/Modbus.Net.Modbus/ModbusUtility.cs
index d2eed40..c665e15 100644
--- a/Modbus.Net/Modbus.Net.Modbus/ModbusUtility.cs
+++ b/Modbus.Net/Modbus.Net.Modbus/ModbusUtility.cs
@@ -36,7 +36,7 @@ namespace Modbus.Net.Modbus
     }
 
     /// <summary>
-    ///     写单个单元的方法接口
+    ///     写单个数据方法接口
     /// </summary>
     public interface IUtilityMethodWriteSingle : IUtilityMethod
     {
@@ -148,18 +148,18 @@ namespace Modbus.Net.Modbus
                     case ModbusType.Rtu:
                     {
                         Wrapper = ConnectionString == null
-                            ? new ModbusRtuProtocol(SlaveAddress, MasterAddress, Endian)
-                            : new ModbusRtuProtocol(ConnectionString, SlaveAddress, MasterAddress, Endian);
+                            ? new ModbusRtuProtocal(SlaveAddress, MasterAddress, Endian)
+                            : new ModbusRtuProtocal(ConnectionString, SlaveAddress, MasterAddress, Endian);
                         break;
                     }
                     //Tcp协议
                     case ModbusType.Tcp:
                     {
                         Wrapper = ConnectionString == null
-                            ? new ModbusTcpProtocol(SlaveAddress, MasterAddress, Endian)
+                            ? new ModbusTcpProtocal(SlaveAddress, MasterAddress, Endian)
                             : (ConnectionStringPort == null
-                                ? new ModbusTcpProtocol(ConnectionString, SlaveAddress, MasterAddress, Endian)
-                                : new ModbusTcpProtocol(ConnectionStringIp, ConnectionStringPort.Value, SlaveAddress,
+                                ? new ModbusTcpProtocal(ConnectionString, SlaveAddress, MasterAddress, Endian)
+                                : new ModbusTcpProtocal(ConnectionStringIp, ConnectionStringPort.Value, SlaveAddress,
                                     MasterAddress, Endian));
                         break;
                     }
@@ -167,18 +167,18 @@ namespace Modbus.Net.Modbus
                     case ModbusType.Ascii:
                     {
                         Wrapper = ConnectionString == null
-                            ? new ModbusAsciiProtocol(SlaveAddress, MasterAddress, Endian)
-                            : new ModbusAsciiProtocol(ConnectionString, SlaveAddress, MasterAddress, Endian);
+                            ? new ModbusAsciiProtocal(SlaveAddress, MasterAddress, Endian)
+                            : new ModbusAsciiProtocal(ConnectionString, SlaveAddress, MasterAddress, Endian);
                         break;
                     }
                     //Rtu协议
                     case ModbusType.RtuInTcp:
                     {
                         Wrapper = ConnectionString == null
-                            ? new ModbusRtuInTcpProtocol(SlaveAddress, MasterAddress, Endian)
+                            ? new ModbusRtuInTcpProtocal(SlaveAddress, MasterAddress, Endian)
                             : (ConnectionStringPort == null
-                                ? new ModbusRtuInTcpProtocol(ConnectionString, SlaveAddress, MasterAddress, Endian)
-                                : new ModbusRtuInTcpProtocol(ConnectionStringIp, ConnectionStringPort.Value, SlaveAddress,
+                                ? new ModbusRtuInTcpProtocal(ConnectionString, SlaveAddress, MasterAddress, Endian)
+                                : new ModbusRtuInTcpProtocal(ConnectionStringIp, ConnectionStringPort.Value, SlaveAddress,
                                     MasterAddress, Endian));
                         break;
                     }
@@ -186,10 +186,10 @@ namespace Modbus.Net.Modbus
                     case ModbusType.AsciiInTcp:
                     {
                         Wrapper = ConnectionString == null
-                            ? new ModbusAsciiInTcpProtocol(SlaveAddress, MasterAddress, Endian)
+                            ? new ModbusAsciiInTcpProtocal(SlaveAddress, MasterAddress, Endian)
                             : (ConnectionStringPort == null
-                                ? new ModbusAsciiInTcpProtocol(ConnectionString, SlaveAddress, MasterAddress, Endian)
-                                : new ModbusAsciiInTcpProtocol(ConnectionStringIp, ConnectionStringPort.Value, SlaveAddress,
+                                ? new ModbusAsciiInTcpProtocal(ConnectionString, SlaveAddress, MasterAddress, Endian)
+                                : new ModbusAsciiInTcpProtocal(ConnectionStringIp, ConnectionStringPort.Value, SlaveAddress,
                                     MasterAddress, Endian));
                         break;
                     }
diff --git a/Tests/Modbus.Net.Tests/EndianTest.cs b/Tests/Modbus.Net.Tests/EndianTest.cs
new file mode 100644
index 0000000..e026cf6
--- /dev/null
+++ b/Tests/Modbus.Net.Tests/EndianTest.cs
@@ -0,0 +1,60 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Modbus.Net.Modbus;
+
+namespace Modbus.Net.Tests
+{
+    [TestClass]
+    public class EndianTest
+    {
+        private BaseMachine _modbusTcpMachine;
+
+        private BaseMachine _modbusTcpMachine2;
+
+        [TestInitialize]
+        public void Init()
+        {
+            _modbusTcpMachine = new ModbusMachine(ModbusType.Tcp, "127.0.0.1", null, true, 1, 0);
+
+            _modbusTcpMachine2 = new ModbusMachine(ModbusType.Tcp, "127.0.0.1", null, true, 1, 0, Endian.LittleEndianLsb);
+        }
+
+        [TestMethod]
+        public async Task ModbusEndianSingle()
+        {
+            Random r = new Random();
+
+            var addresses = new List<AddressUnit>
+            {
+                new AddressUnit
+                {
+                    Id = "0",
+                    Area = "4X",
+                    Address = 1,
+                    SubAddress = 0,
+                    CommunicationTag = "A1",
+                    DataType = typeof(ushort)
+                }
+            };
+
+            var dic1 = new Dictionary<string, double>()
+            {
+                {
+                    "4X 1", r.Next(0, UInt16.MaxValue)
+                }
+            };
+
+            _modbusTcpMachine.GetAddresses = addresses;
+            _modbusTcpMachine2.GetAddresses = addresses;
+            await _modbusTcpMachine.SetDatasAsync(MachineSetDataType.Address, dic1);
+            var ans = await _modbusTcpMachine.GetDatasAsync(MachineGetDataType.Address);
+            var ans2 = await _modbusTcpMachine2.GetDatasAsync(MachineGetDataType.Address);
+            Assert.AreEqual(ans["4X 1.0"].PlcValue, dic1["4X 1"]);
+            Assert.AreEqual(ans2["4X 1.0"].PlcValue, (ushort)dic1["4X 1"] % 256 * 256 + (ushort)dic1["4X 1"] / 256);
+        }
+    }
+}
diff --git a/Tests/Modbus.Net.Tests/Modbus.Net.Tests.csproj b/Tests/Modbus.Net.Tests/Modbus.Net.Tests.csproj
index 0d888dc..a10ed78 100644
--- a/Tests/Modbus.Net.Tests/Modbus.Net.Tests.csproj
+++ b/Tests/Modbus.Net.Tests/Modbus.Net.Tests.csproj
@@ -52,6 +52,7 @@
     </Otherwise>
   </Choose>
   <ItemGroup>
+    <Compile Include="EndianTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ModbusTest.cs" />
     <Compile Include="SiemensTest.cs" />