Update

Modbus.Net/Modbus.Net.Modbus/ModbusRtuProtocolReceiver.cs

@@ -17,16 +17,49 @@ namespace Modbus.Net.Modbus
                 return receiveBytes =>
                 {
                     var writeContent = receiveBytes.Length > 6 ? new byte[receiveBytes.Length - 7] : null;
-                    if (receiveBytes.Length > 6) Array.Copy(receiveBytes, 7, writeContent, 0, receiveBytes.Length - 7);
+                    if (receiveBytes.Length > 6)
-                    return new ReceiveDataDef()
                     {
-                        SlaveAddress = receiveBytes[0],
+                        Array.Copy(receiveBytes, 7, writeContent, 0, receiveBytes.Length - 7);
-                        FunctionCode = receiveBytes[1],
+                        return new ReceiveDataDef()
-                        StartAddress = (ushort)(receiveBytes[2] * 256 + receiveBytes[3]),
+                        {
-                        Count = (ushort)(receiveBytes[4] * 256 + receiveBytes[5]),
+                            SlaveAddress = receiveBytes[0],
-                        WriteByteCount = (byte)(receiveBytes.Length > 6 ? receiveBytes[6] : 0),
+                            FunctionCode = receiveBytes[1],
-                        WriteContent = writeContent
+                            StartAddress = (ushort)(receiveBytes[2] * 256 + receiveBytes[3]),
-                    };
+                            Count = (ushort)(receiveBytes[4] * 256 + receiveBytes[5]),
+                            WriteByteCount = (byte)(receiveBytes.Length > 6 ? receiveBytes[6] : 0),
+                            WriteContent = writeContent
+                        };
+                    }
+                    else if (receiveBytes.Length == 6)
+                    {
+                        if (receiveBytes[1] == 1 || receiveBytes[1] == 2)
+                        {
+                            writeContent = null;
+                            return new ReceiveDataDef()
+                            {
+                                SlaveAddress = receiveBytes[0],
+                                FunctionCode = receiveBytes[1],
+                                StartAddress = (ushort)(receiveBytes[2] * 256 + receiveBytes[3]),
+                                Count = (ushort)(receiveBytes[4] * 256 + receiveBytes[5]),
+                                WriteByteCount = 2,
+                                WriteContent = writeContent
+                            };
+                        }
+                        else
+                        {
+                            writeContent = new byte[2] { receiveBytes[4], receiveBytes[5] };
+                            return new ReceiveDataDef()
+                            {
+                                SlaveAddress = receiveBytes[0],
+                                FunctionCode = receiveBytes[1],
+                                StartAddress = (ushort)(receiveBytes[2] * 256 + receiveBytes[3]),
+                                Count = 1,
+                                WriteByteCount = 2,
+                                WriteContent = writeContent
+                            };
+                        }
+                    }
+                    else return null;
                 };
             }
         }

Samples/ModbusTcpToRtu/ModbusTcpToRtu.csproj

@@ -7,6 +7,16 @@
     <UserSecretsId>dotnet-ModbusTcpToRtu-b7b7d9ed-80ce-4790-86de-5c3cf21e0a2e</UserSecretsId>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Remove="service.bat" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Content Include="service.bat">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+
 	<ItemGroup>
 		<PackageReference Include="Microsoft.Extensions.Hosting" Version="7.0.1" />
 		<PackageReference Include="Microsoft.Extensions.Hosting.WindowsServices" Version="7.0.1" />

Samples/ModbusTcpToRtu/appsettings.Production.json

@@ -0,0 +1,21 @@
+{
+  "Serilog": {
+    "MinimumLevel": {
+      "Default": "Error",
+      "Override": {
+        "Microsoft": "Error",
+        "Microsoft.Hosting.Lifetime": "Error"
+      }
+    }
+  },
+  "Logging": {
+    "LogLevel": {
+      "Default": "Error",
+      "Microsoft": "Error",
+      "Microsoft.Hosting.Lifetime": "Error"
+    }
+  },
+  "Quartz": {
+    "LogLevel": "Error"
+  }
+}

Samples/ModbusTcpToRtu/service.bat

@@ -0,0 +1,4 @@
+sc delete ModbusTcpToRtu 
+sc create ModbusTcpToRtu "binPath=%~dp0ModbusTcpToRtu.exe" start= delayed-auto
+sc start ModbusTcpToRtu
+pause