diff --git a/IoTSharp.Gateway.Modbus.csproj b/IoTSharp.Gateway.Modbus.csproj
index df2e324..ccbcb6f 100644
--- a/IoTSharp.Gateway.Modbus.csproj
+++ b/IoTSharp.Gateway.Modbus.csproj
@@ -2,11 +2,15 @@
 
   <PropertyGroup>
     <TargetFramework>net6.0</TargetFramework>
-    <Nullable>enable</Nullable>
+    <Nullable>annotations</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
     <UserSecretsId>aspnet-IoTSharp.Gateway.Modbus-554A6128-AB47-40BC-8BC3-40D3123C6BFF</UserSecretsId>
     <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>
     <DockerfileContext>.</DockerfileContext>
+	  <RestoreAdditionalProjectSources>
+		  https://api.nuget.org/v3/index.json;
+		  https://www.myget.org/F/iotsharp/api/v3/index.json;
+	  </RestoreAdditionalProjectSources>
   </PropertyGroup>
 
   <ItemGroup>
@@ -14,19 +18,20 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="AMWD.Modbus.Common" Version="1.2.0" />
+    <PackageReference Include="AMWD.Modbus.Common" Version="1.2.1-1" />
     <PackageReference Include="AMWD.Modbus.Proxy" Version="1.2.0" />
     <PackageReference Include="AMWD.Modbus.Serial" Version="1.2.0" />
     <PackageReference Include="AMWD.Modbus.Tcp" Version="1.2.0" />
+	  <PackageReference Include="Modbus.SerialOverTCP" Version="1.2.1-1" />
     <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="6.0.*" />
     <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="6.0.*" />
     <PackageReference Include="Microsoft.AspNetCore.Identity.UI" Version="6.0.*" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="6.0.*" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="6.0.*" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="6.0.*" />
     <PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.16.1" />
     <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="6.0.*" />
     <PackageReference Include="MQTTnet" Version="4.0.2.221" />
+    <PackageReference Include="System.Text.Encoding.CodePages" Version="6.0.0" />
   </ItemGroup>
 
 </Project>
diff --git a/Pages/PointMapAdmin/Index.cshtml.cs b/Pages/PointMapAdmin/Index.cshtml.cs
index 82d5084..da83283 100644
--- a/Pages/PointMapAdmin/Index.cshtml.cs
+++ b/Pages/PointMapAdmin/Index.cshtml.cs
@@ -23,7 +23,7 @@ namespace IoTSharp.Gateway.Modbus.Pages.PointMapAdmin
         public async Task OnGetAsync(Guid id)
         {
             SlaveId = id;
-            if (_context.PointMappings != null && id!=null)
+            if (_context.PointMappings != null && id!=Guid.Empty)
             {
                 PointMapping = await _context.PointMappings.Include(pt => pt.Owner).Where(fm => fm.Owner!=null &&  fm.Owner.Id == id).ToListAsync();
             }
diff --git a/Program.cs b/Program.cs
index 862a33a..a9d9267 100644
--- a/Program.cs
+++ b/Program.cs
@@ -9,6 +9,7 @@ namespace IoTSharp.Gateway.Modbus
     {
         public static void Main(string[] args)
         {
+            System.Text.Encoding.RegisterProvider(System.Text.CodePagesEncodingProvider.Instance);
             var builder = WebApplication.CreateBuilder(args);
             // Add services to the container.
             var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? throw new InvalidOperationException("Connection string 'DefaultConnection' not found.");
diff --git a/Services/ModbusMaster.cs b/Services/ModbusMaster.cs
index 7deae3c..16eae3e 100644
--- a/Services/ModbusMaster.cs
+++ b/Services/ModbusMaster.cs
@@ -74,7 +74,7 @@ namespace IoTSharp.Gateway.Modbus.Services
             } while (!stoppingToken.IsCancellationRequested);
         }
 
-        private async Task ReadDatas(ModbusSlave slave, IModbusClient? client, CancellationToken stoppingToken)
+        private async Task ReadDatas(ModbusSlave slave, IModbusClient client, CancellationToken stoppingToken)
         {
             var points = _dbContext.PointMappings.Include(p => p.Owner).Where(p => p.Owner == slave).ToList();
             foreach (var point in points)
@@ -259,14 +259,12 @@ namespace IoTSharp.Gateway.Modbus.Services
                     ParseDtuParam(url, dtu);
                     client = dtu;
                     break;
-
                 case "tcp":
                     client = new AMWD.Modbus.Tcp.Client.ModbusClient(url.Host, url.Port, mlog);
                     break;
-
                 case "d2t":
-                  //  client = new AMWD.Modbus.Tcp.Client.ModbusClient(url.Host, url.Port, mlog);
-             
+                    client = new AMWD.Modbus.SerialOverTCP.Client.ModbusClient(url.Host, url.Port, mlog);
+                    break;
                 default:
                     break;
             }