diff --git a/Borepin/Borepin/App.xaml.cs b/Borepin/Borepin/App.xaml.cs
index 3eec22d..238f247 100644
--- a/Borepin/Borepin/App.xaml.cs
+++ b/Borepin/Borepin/App.xaml.cs
@@ -39,6 +39,7 @@ namespace Borepin
                 result = await NavigationService.NavigateAsync("/MainPage/NavigationPage/ServerListPage");
             }
 
+            //result = await NavigationService.NavigateAsync("/NavigationPage/TestPage");
             if (!result.Success)
             {
                 System.Diagnostics.Debugger.Break();
@@ -59,6 +60,7 @@ namespace Borepin
             containerRegistry.RegisterForNavigation<ServerListPage, ServerListPageModel>();
             containerRegistry.RegisterForNavigation<ServerPage, ServerPageModel>();
             containerRegistry.RegisterForNavigation<ListPage, ListPageModel>();
+            containerRegistry.RegisterForNavigation<TestPage, TestPageModel>();
 
             // Register Dialog
             containerRegistry.RegisterDialog<ConfirmDialog, ConfirmDialogModel>();
diff --git a/Borepin/Borepin/Base/PageModelBase.cs b/Borepin/Borepin/Base/PageModelBase.cs
new file mode 100644
index 0000000..4d37cb6
--- /dev/null
+++ b/Borepin/Borepin/Base/PageModelBase.cs
@@ -0,0 +1,48 @@
+using Prism.Mvvm;
+using Prism.Navigation;
+using System.Threading.Tasks;
+
+namespace Borepin.Base
+{
+    /// <summary>
+    /// Base for all BFFH Based PageModels
+    /// </summary>
+    public abstract class PageModelBase : BindableBase, INavigationAware
+    {
+        #region Private Properties
+        protected readonly INavigationService _NavigationService;
+        #endregion
+
+        #region Contructors
+        public PageModelBase(INavigationService navigationService)
+        {
+            _NavigationService = navigationService;
+        }
+        #endregion
+
+        #region Properties
+        /// <summary>
+        /// PageModel is Busy
+        /// </summary>
+        private bool _IsBusy = true;
+        public bool IsBusy
+        {
+            get => _IsBusy;
+            set => SetProperty(ref _IsBusy, value);
+        }
+        #endregion
+
+        #region Data
+        /// <summary>
+        /// Load Data async
+        /// </summary>
+        /// <returns></returns>
+        public abstract Task<bool> LoadData();
+        #endregion
+
+        #region INavigationAware
+        public abstract void OnNavigatedFrom(INavigationParameters parameters);
+        public abstract void OnNavigatedTo(INavigationParameters parameters);
+        #endregion
+    }
+}
\ No newline at end of file
diff --git a/Borepin/Borepin/Borepin.csproj b/Borepin/Borepin/Borepin.csproj
index 7ec38ab..5628c8e 100644
--- a/Borepin/Borepin/Borepin.csproj
+++ b/Borepin/Borepin/Borepin.csproj
@@ -82,6 +82,9 @@
     <EmbeddedResource Update="Page\SettingsPage.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Update="Page\TestPage.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
     <EmbeddedResource Update="Properties\Resources.resx">
       <Generator>ResXFileCodeGenerator</Generator>
       <LastGenOutput>Resources.Designer.cs</LastGenOutput>
@@ -93,6 +96,9 @@
     <EmbeddedResource Update="Styles\LightTheme.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Update="View\IsBusyView.xaml">
+      <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
+    </EmbeddedResource>
     <EmbeddedResource Update="View\ListItemView.xaml">
       <Generator>MSBuild:UpdateDesignTimeXaml</Generator>
     </EmbeddedResource>
@@ -101,7 +107,6 @@
     </EmbeddedResource>
   </ItemGroup>
   <ItemGroup>
-    <Folder Include="Base\" />
     <Folder Include="Behaviour\" />
   </ItemGroup>
   <ItemGroup>
diff --git a/Borepin/Borepin/Page/MachineListPage.xaml b/Borepin/Borepin/Page/MachineListPage.xaml
index 0f10107..bd0e5a4 100644
--- a/Borepin/Borepin/Page/MachineListPage.xaml
+++ b/Borepin/Borepin/Page/MachineListPage.xaml
@@ -2,21 +2,32 @@
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
              xmlns:views="clr-namespace:Borepin.View"
-             x:Class="Borepin.Page.MachineListPage">
+             x:Class="Borepin.Page.MachineListPage"
+             xmlns:converters="clr-namespace:Borepin.Converter">
     <NavigationPage.TitleView>
         <Label Text="Machines" HorizontalOptions="End" Margin="0, 0, 10, 0" VerticalOptions="CenterAndExpand" FontSize="Medium" TextColor="{StaticResource FirstColor}"/>
     </NavigationPage.TitleView>
+    <ContentPage.Resources>
+        <ResourceDictionary>
+            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
+        </ResourceDictionary>
+    </ContentPage.Resources>
     <ContentPage.Content>
-        <StackLayout>
-            <ListView ItemsSource="{Binding MachineListItemViewModel_List}">
-                <ListView.ItemTemplate>
-                    <DataTemplate> 
-                        <ViewCell>
-                            <views:MachineListItemView />
-                        </ViewCell>
-                    </DataTemplate>
-                </ListView.ItemTemplate>
-            </ListView>
+        <StackLayout Padding="20">
+            <StackLayout IsVisible="{Binding IsBusy}">
+                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
+            </StackLayout>
+            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
+                <ListView ItemsSource="{Binding MachineListItemViewModel_List}">
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <views:MachineListItemView />
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
+            </StackLayout>
         </StackLayout>
     </ContentPage.Content>
 </ContentPage>
\ No newline at end of file
diff --git a/Borepin/Borepin/Page/MachinePage.xaml b/Borepin/Borepin/Page/MachinePage.xaml
index 347475f..3e65181 100644
--- a/Borepin/Borepin/Page/MachinePage.xaml
+++ b/Borepin/Borepin/Page/MachinePage.xaml
@@ -10,14 +10,20 @@
         <ResourceDictionary>
             <converters:MachineStateColorConverter x:Key="MachineStateColorConverter"/>
             <converters:IsNotNullBoolConverter x:Key="IsNotNullBoolConverter"/>
+            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
         </ResourceDictionary>
     </ContentPage.Resources>
     <ContentPage.Content>
         <StackLayout Padding="20">
-            <Label Text="{Binding Name}" Style="{StaticResource LabelStyle_Title}"/>
+            <StackLayout IsVisible="{Binding IsBusy}">
+                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
+            </StackLayout>
+            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
+                <Label Text="{Binding Name}" Style="{StaticResource LabelStyle_Title}"/>
 
-            <Button Text="Use" Command="{Binding UseMachineCommand}" IsVisible="{Binding CanUse}" Style="{StaticResource ButtonStyle_Primary}"/>
-            <Button Text="GiveBack" Command="{Binding GiveBackMachineCommand}" IsVisible="{Binding CanGiveBack}" Style="{StaticResource ButtonStyle_Primary}"/>
+                <Button Text="Use" Command="{Binding UseMachineCommand}" IsVisible="{Binding CanUse}" Style="{StaticResource ButtonStyle_Primary}"/>
+                <Button Text="GiveBack" Command="{Binding GiveBackMachineCommand}" IsVisible="{Binding CanGiveBack}" Style="{StaticResource ButtonStyle_Primary}"/>
+            </StackLayout>
         </StackLayout>
     </ContentPage.Content>
 </ContentPage>
\ No newline at end of file
diff --git a/Borepin/Borepin/Page/ServerListPage.xaml b/Borepin/Borepin/Page/ServerListPage.xaml
index 292c178..7d16fa7 100644
--- a/Borepin/Borepin/Page/ServerListPage.xaml
+++ b/Borepin/Borepin/Page/ServerListPage.xaml
@@ -2,33 +2,44 @@
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
              xmlns:views="clr-namespace:Borepin.View"
-             x:Class="Borepin.Page.ServerListPage">
+             x:Class="Borepin.Page.ServerListPage"
+             xmlns:converters="clr-namespace:Borepin.Converter">
     <NavigationPage.TitleView>
         <Label Text="Servers" HorizontalOptions="End" Margin="0, 0, 10, 0" VerticalOptions="CenterAndExpand" FontSize="Medium" TextColor="{StaticResource FirstColor}"/>
     </NavigationPage.TitleView>
+    <ContentPage.Resources>
+        <ResourceDictionary>
+            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
+        </ResourceDictionary>
+    </ContentPage.Resources>
     <ContentPage.Content>
-        <StackLayout>
-            <Label Text="Active Connection" IsVisible="{Binding HasActiveConnection}"/>
-            <ListView ItemsSource="{Binding ActiveConnection}" IsVisible="{Binding HasActiveConnection}">
-                <ListView.ItemTemplate>
-                    <DataTemplate>
-                        <ViewCell>
-                            <views:ServerListItemView />
-                        </ViewCell>
-                    </DataTemplate>
-                </ListView.ItemTemplate>
-            </ListView>
-            <Label Text="Last Connections"/>
-            <ListView ItemsSource="{Binding ServerListItemViewModel_List}">
-                <ListView.ItemTemplate>
-                    <DataTemplate>
-                        <ViewCell>
-                            <views:ServerListItemView />
-                        </ViewCell>
-                    </DataTemplate>
-                </ListView.ItemTemplate>
-            </ListView>
-            <Button Text="Connect to new Server" Command="{Binding AddInstancesCommand}"/>
+        <StackLayout Padding="20">
+            <StackLayout IsVisible="{Binding IsBusy}">
+                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
+            </StackLayout>
+            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
+                <Label Text="Active Connection" IsVisible="{Binding HasActiveConnection}"/>
+                <ListView ItemsSource="{Binding ActiveConnection}" IsVisible="{Binding HasActiveConnection}">
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <views:ServerListItemView />
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
+                <Label Text="Last Connections"/>
+                <ListView ItemsSource="{Binding ServerListItemViewModel_List}">
+                    <ListView.ItemTemplate>
+                        <DataTemplate>
+                            <ViewCell>
+                                <views:ServerListItemView />
+                            </ViewCell>
+                        </DataTemplate>
+                    </ListView.ItemTemplate>
+                </ListView>
+                <Button Text="Connect to new Server" Command="{Binding AddInstancesCommand}"/>
+            </StackLayout>
         </StackLayout>
     </ContentPage.Content>
 </ContentPage>
\ No newline at end of file
diff --git a/Borepin/Borepin/Page/ServerPage.xaml b/Borepin/Borepin/Page/ServerPage.xaml
index 39c6a02..18b5329 100644
--- a/Borepin/Borepin/Page/ServerPage.xaml
+++ b/Borepin/Borepin/Page/ServerPage.xaml
@@ -2,18 +2,23 @@
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              x:Class="Borepin.Page.ServerPage"
-             xmlns:converter="clr-namespace:Borepin.Converter">
+             xmlns:converters="clr-namespace:Borepin.Converter">
     <ContentPage.Resources>
         <ResourceDictionary>
-            <converter:InvertBoolConverter x:Key="invertBool" />
+            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
         </ResourceDictionary>
     </ContentPage.Resources>
     <ContentPage.Content>
-        <StackLayout>
-            <Label Text="{Binding Connection_Item.Address}"/>
-            <Button IsVisible="{Binding IsConnected, Converter={StaticResource invertBool}}" Text="Connect" Command="{Binding ConnectCommand}"/>
-            <Button IsVisible="{Binding IsConnected}" Text="Disconnect" Command="{Binding ConnectCommand}"/>
-            <Button Text="Delete" Command="{Binding DeleteCommand}"/>
+        <StackLayout Padding="20">
+            <StackLayout IsVisible="{Binding IsBusy}">
+                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
+            </StackLayout>
+            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
+                <Label Text="{Binding Connection_Item.Address}"/>
+                <Button IsVisible="{Binding IsConnected, Converter={StaticResource InvertBoolConverter}}" Text="Connect" Command="{Binding ConnectCommand}"/>
+                <Button IsVisible="{Binding IsConnected}" Text="Disconnect" Command="{Binding ConnectCommand}"/>
+                <Button Text="Delete" Command="{Binding DeleteCommand}"/>
+            </StackLayout>
         </StackLayout>
     </ContentPage.Content>
 </ContentPage>
\ No newline at end of file
diff --git a/Borepin/Borepin/Page/TestPage.xaml b/Borepin/Borepin/Page/TestPage.xaml
new file mode 100644
index 0000000..8018b7d
--- /dev/null
+++ b/Borepin/Borepin/Page/TestPage.xaml
@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Borepin.Page.TestPage"
+             xmlns:converters="clr-namespace:Borepin.Converter">
+    <ContentPage.Resources>
+        <ResourceDictionary>
+            <converters:InvertBoolConverter x:Key="InvertBoolConverter"/>
+        </ResourceDictionary>
+    </ContentPage.Resources>
+    <ContentPage.Content>
+        <StackLayout Padding="20">
+            <StackLayout IsVisible="{Binding IsBusy}">
+                <ActivityIndicator IsRunning="{Binding IsBusy}"></ActivityIndicator>
+            </StackLayout>
+            <StackLayout IsVisible="{Binding IsBusy, Converter={StaticResource InvertBoolConverter}}">
+                <Label Text="TestPage"/>
+            </StackLayout>
+        </StackLayout>
+    </ContentPage.Content>
+</ContentPage>
\ No newline at end of file
diff --git a/Borepin/Borepin/Page/TestPage.xaml.cs b/Borepin/Borepin/Page/TestPage.xaml.cs
new file mode 100644
index 0000000..b78f7d1
--- /dev/null
+++ b/Borepin/Borepin/Page/TestPage.xaml.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using Xamarin.Forms;
+using Xamarin.Forms.Xaml;
+
+namespace Borepin.Page
+{
+    [XamlCompilation(XamlCompilationOptions.Compile)]
+    public partial class TestPage : ContentPage
+    {
+        public TestPage()
+        {
+            InitializeComponent();
+        }
+    }
+}
\ No newline at end of file
diff --git a/Borepin/Borepin/PageModel/MachineListPageModel.cs b/Borepin/Borepin/PageModel/MachineListPageModel.cs
index d5e0804..f4e6644 100644
--- a/Borepin/Borepin/PageModel/MachineListPageModel.cs
+++ b/Borepin/Borepin/PageModel/MachineListPageModel.cs
@@ -1,5 +1,4 @@
 using Borepin.ViewModel;
-using Prism.Mvvm;
 using System.Collections.Generic;
 using System.Threading.Tasks;
 using System.Windows.Input;
@@ -8,53 +7,70 @@ using Prism.Navigation;
 using Borepin.Service.Connections;
 using Borepin.Service.BFFH;
 using Borepin.Model;
+using Borepin.Base;
 
 namespace Borepin.PageModel
 {
-    public class MachineListPageModel : BindableBase, INavigationAware
+    public class MachineListPageModel : PageModelBase
     {
-        private readonly INavigationService _NavigationService;
+        #region Private Properties
         private readonly IConnectionService _ConnectionService;
         private readonly IBFFHService _BFFHService;
+        #endregion
 
-        public MachineListPageModel(INavigationService navigationService, IConnectionService connectionService, IBFFHService bffhService)
+        #region Constructors
+        public MachineListPageModel(INavigationService navigationService, IConnectionService connectionService, IBFFHService bFFHService) : base(navigationService)
         {
-            _NavigationService = navigationService;
             _ConnectionService = connectionService;
-            _BFFHService = bffhService;
+            _BFFHService = bFFHService;
 
             SelectInstanceCommand = new DelegateCommand<object>(SelectInstanceCommandExecuted);
         }
+        #endregion
 
-        private async Task<bool> LoadData()
+        #region Data
+        public override async Task<bool> LoadData()
         {
-            if(_BFFHService.ActiveConnection == null)
+            if (_BFFHService.ActiveConnection == null)
             {
                 return await Task.FromResult(true);
             }
+            else
+            {
+                IsConnected = true;
+            }
 
             FabAccessAPI.Machines machineInterface = await _BFFHService.GetMachineInterface();
 
             List<Machine> list = new List<Machine>();
 
             IReadOnlyList<FabAccessAPI.Machine> machine_list = await machineInterface.ListMachines();
-            foreach(FabAccessAPI.Machine machine in machine_list)
+            foreach (FabAccessAPI.Machine machine in machine_list)
             {
                 list.Add(new Machine() { Instance = machine, MInfo = await machine.GetMInfo() });
             }
 
             List<MachineListItemViewModel> viewmodel_list = new List<MachineListItemViewModel>();
-            foreach(Machine machine in list)
+            foreach (Machine machine in list)
             {
                 viewmodel_list.Add(new MachineListItemViewModel(machine));
             }
 
             MachineListItemViewModel_List = viewmodel_list;
 
+            IsBusy = false;
             return await Task.FromResult(true);
         }
+        #endregion
 
         #region Properties
+        private bool _IsConnected = false;
+        public bool IsConnected
+        {
+            get => _IsConnected;
+            set => SetProperty(ref _IsConnected, value);
+        }
+
         private List<MachineListItemViewModel> _MachineListItemViewModel_List;
         public List<MachineListItemViewModel> MachineListItemViewModel_List
         {
@@ -88,13 +104,14 @@ namespace Borepin.PageModel
         #endregion
 
         #region INavigationAware
-        public void OnNavigatedFrom(INavigationParameters parameters)
+        public override void OnNavigatedFrom(INavigationParameters parameters)
         {
             
         }
 
-        public void OnNavigatedTo(INavigationParameters parameters)
+        public override void OnNavigatedTo(INavigationParameters parameters)
         {
+            IsBusy = true;
             Task.Run(LoadData);
         }
         #endregion
diff --git a/Borepin/Borepin/PageModel/MachinePageModel.cs b/Borepin/Borepin/PageModel/MachinePageModel.cs
index 5548a24..9b5f562 100644
--- a/Borepin/Borepin/PageModel/MachinePageModel.cs
+++ b/Borepin/Borepin/PageModel/MachinePageModel.cs
@@ -1,26 +1,43 @@
-using Borepin.Model;
+using Borepin.Base;
+using Borepin.Model;
 using Prism.Commands;
-using Prism.Mvvm;
 using Prism.Navigation;
+using System.Threading.Tasks;
 using System.Windows.Input;
 using static FabAccessAPI.Schema.Machine.WriteInterface;
 
 namespace Borepin.PageModel
 {
-    public class MachinePageModel : BindableBase, INavigationAware
+    public class MachinePageModel : PageModelBase
     {
-        private readonly INavigationService _NavigationService;
-
-        public MachinePageModel(INavigationService navigationService)
+        #region Contructors
+        public MachinePageModel(INavigationService navigationService) : base(navigationService)
         {
-            _NavigationService = navigationService;
-
             UseMachineCommand = new DelegateCommand(UseMachineCommandExecuted);
             GiveBackMachineCommand = new DelegateCommand(GiveBackMachineCommandExecuted);
         }
+        #endregion
+
+        #region Data
+        public override async Task<bool> LoadData()
+        {
+            Name = MachineItem.MInfo.Name;
+
+            CanUse = MachineItem.MInfo.State == FabAccessAPI.Schema.State.free;
+
+            //if (GiveBack == null)
+            //{
+            //    GiveBack = await MachineItem.Instance.GetGiveBack();
+            //}
+
+            CanGiveBack = GiveBack != null;
+
+            IsBusy = false;
+            return await Task.FromResult(true);
+        }
+        #endregion
 
         #region Properties
-
         private Machine _MachineItem;
         public Machine MachineItem
         {
@@ -36,11 +53,11 @@ namespace Borepin.PageModel
         }
 
         private IGiveBack _GiveBack;
-        //public IGiveBack GiveBack
-        //{
-        //    get => _GiveBack;
-        //    set => SetProperty(ref _GiveBack, value);
-        //}
+        public IGiveBack GiveBack
+        {
+            get => _GiveBack;
+            set => SetProperty(ref _GiveBack, value);
+        }
 
         private bool _CanUse;
         public bool CanUse
@@ -55,7 +72,6 @@ namespace Borepin.PageModel
             get => _CanGiveBack;
             set => SetProperty(ref _CanGiveBack, value);
         }
-
         #endregion
 
         #region Commands
@@ -68,8 +84,8 @@ namespace Borepin.PageModel
 
         private async void UseMachineCommandExecuted()
         {
-            _GiveBack = await MachineItem.Instance.Use();
-            CanGiveBack = _GiveBack != null;
+            GiveBack = await MachineItem.Instance.Use();
+            CanGiveBack = GiveBack != null;
 
             MachineItem.MInfo = await MachineItem.Instance.GetMInfo();
 
@@ -85,10 +101,10 @@ namespace Borepin.PageModel
 
         private async void GiveBackMachineCommandExecuted()
         {
-            await _GiveBack.Ret();
+            await GiveBack.Ret();
 
-            _GiveBack = null;
-            CanGiveBack = _GiveBack != null;
+            GiveBack = null;
+            CanGiveBack = GiveBack != null;
 
             MachineItem.MInfo = await MachineItem.Instance.GetMInfo();
 
@@ -97,20 +113,18 @@ namespace Borepin.PageModel
 
         #endregion
 
-        #region INavigationAware
-        public void OnNavigatedFrom(INavigationParameters parameters)
+        #region INavigationService
+        public override void OnNavigatedFrom(INavigationParameters parameters)
         {
             
         }
 
-        public void OnNavigatedTo(INavigationParameters parameters)
+        public override void OnNavigatedTo(INavigationParameters parameters)
         {
             MachineItem = parameters["instance"] as Machine;
-            
-            Name = MachineItem.MInfo.Name;
 
-            CanUse = MachineItem.MInfo.State == FabAccessAPI.Schema.State.free;
-            CanGiveBack = _GiveBack != null;
+            IsBusy = true;
+            Task.Run(LoadData);
         }
         #endregion
     }
diff --git a/Borepin/Borepin/PageModel/ServerListPageModel.cs b/Borepin/Borepin/PageModel/ServerListPageModel.cs
index fe78b1e..e7d5016 100644
--- a/Borepin/Borepin/PageModel/ServerListPageModel.cs
+++ b/Borepin/Borepin/PageModel/ServerListPageModel.cs
@@ -9,26 +9,30 @@ using Prism.Commands;
 using Prism.Navigation;
 using Borepin.Service.Connections;
 using Borepin.Service.BFFH;
+using Borepin.Base;
 
 namespace Borepin.PageModel
 {
-    public class ServerListPageModel : BindableBase, INavigationAware
+    public class ServerListPageModel : PageModelBase
     {
-        private readonly INavigationService _NavigationService;
+        #region Private Properties
         private readonly IConnectionService _ConnectionService;
         private readonly IBFFHService _BFFHService;
+        #endregion
 
-        public ServerListPageModel(INavigationService navigationService, IConnectionService connectionService, IBFFHService bffhService)
+        #region Constructors
+        public ServerListPageModel(INavigationService navigationService, IConnectionService connectionService, IBFFHService bffhService) : base(navigationService)
         {
-            _NavigationService = navigationService;
             _ConnectionService = connectionService;
             _BFFHService = bffhService;
 
             AddInstancesCommand = new DelegateCommand(AddInstancesCommandExecuted);
             SelectInstanceCommand = new DelegateCommand<object>(SelectInstanceCommandExecuted);
         }
+        #endregion
 
-        private async Task<bool> LoadData()
+        #region Data
+        public override async Task<bool> LoadData()
         {
             List<Connection> list = await _ConnectionService.GetConnectionList();
             if (_BFFHService.ActiveConnection != null)
@@ -47,12 +51,12 @@ namespace Borepin.PageModel
                 HasActiveConnection = false;
             }
 
-            //list = (List<Connection>)list.OrderBy(x => x.LastTime);
-
             ServerListItemViewModel_List = list.Select(x => new ServerListItemViewModel(x)).ToList();
 
+            IsBusy = false;
             return await Task.FromResult(true);
         }
+        #endregion
 
         #region Properties
         private List<ServerListItemViewModel> _ServerListItemViewModel_List;
@@ -117,13 +121,14 @@ namespace Borepin.PageModel
         #endregion
 
         #region INavigationAware
-        public void OnNavigatedFrom(INavigationParameters parameters)
+        public override void OnNavigatedFrom(INavigationParameters parameters)
         {
-            
+
         }
 
-        public void OnNavigatedTo(INavigationParameters parameters)
+        public override void OnNavigatedTo(INavigationParameters parameters)
         {
+            IsBusy = true;
             Task.Run(LoadData);
         }
         #endregion
diff --git a/Borepin/Borepin/PageModel/ServerPageModel.cs b/Borepin/Borepin/PageModel/ServerPageModel.cs
index e450157..1956a54 100644
--- a/Borepin/Borepin/PageModel/ServerPageModel.cs
+++ b/Borepin/Borepin/PageModel/ServerPageModel.cs
@@ -1,4 +1,5 @@
-using Borepin.Model;
+using Borepin.Base;
+using Borepin.Model;
 using Borepin.Service.BFFH;
 using Borepin.Service.Connections;
 using Borepin.Service.Credentials;
@@ -11,17 +12,18 @@ using System.Windows.Input;
 
 namespace Borepin.PageModel
 {
-    public class ServerPageModel : BindableBase, INavigationAware
+    public class ServerPageModel : PageModelBase
     {
-        private readonly INavigationService _NavigationService;
+        #region Private Properties
         private readonly IDialogService _DialogService;
         private readonly IConnectionService _ConnectionService;
         private readonly IBFFHService _BFFHService;
         private readonly ICredentialService _CredentialService;
+        #endregion
 
-        public ServerPageModel(INavigationService navigationService, IDialogService dialogService, IConnectionService connectionService, IBFFHService bffhService, ICredentialService credentialService)
+        #region Constructors
+        public ServerPageModel(INavigationService navigationService, IDialogService dialogService, IConnectionService connectionService, IBFFHService bffhService, ICredentialService credentialService) : base(navigationService)
         {
-            _NavigationService = navigationService;
             _DialogService = dialogService;
 
             _ConnectionService = connectionService;
@@ -31,6 +33,14 @@ namespace Borepin.PageModel
             ConnectCommand = new DelegateCommand(async () => await ConnectCommandExecuted());
             DeleteCommand = new DelegateCommand(DeleteCommandExecuted);
         }
+        #endregion
+
+        #region Data
+        public override Task<bool> LoadData()
+        {
+            throw new System.NotImplementedException();
+        }
+        #endregion
 
         #region Properties
         private Connection _Connection_Item;
@@ -58,6 +68,8 @@ namespace Borepin.PageModel
 
         private async Task ConnectCommandExecuted()
         {
+            IsBusy = true;
+
             if(IsConnected)
             {
                 _BFFHService.Disconnect();
@@ -71,6 +83,8 @@ namespace Borepin.PageModel
 
                 IsConnected = true;
             }
+
+            IsBusy = false;
         }
 
         private ICommand _DeleteCommand;
@@ -122,16 +136,16 @@ namespace Borepin.PageModel
         #endregion
 
         #region INavigationAware
-        public void OnNavigatedFrom(INavigationParameters parameters)
+        public override void OnNavigatedFrom(INavigationParameters parameters)
         {
             
         }
 
-        public void OnNavigatedTo(INavigationParameters parameters)
+        public override void OnNavigatedTo(INavigationParameters parameters)
         {
             Connection_Item = parameters["instance"] as Connection;
 
-            if(_BFFHService.ActiveConnection != null && Connection_Item != null)
+            if (_BFFHService.ActiveConnection != null && Connection_Item != null)
             {
                 IsConnected = Connection_Item.Equals(_BFFHService.ActiveConnection);
             }
@@ -139,6 +153,8 @@ namespace Borepin.PageModel
             {
                 IsConnected = false;
             }
+
+            IsBusy = false;
         }
         #endregion
     }
diff --git a/Borepin/Borepin/PageModel/TestPageModel.cs b/Borepin/Borepin/PageModel/TestPageModel.cs
new file mode 100644
index 0000000..5ec16b8
--- /dev/null
+++ b/Borepin/Borepin/PageModel/TestPageModel.cs
@@ -0,0 +1,39 @@
+using Borepin.Base;
+using Prism.Navigation;
+using System.Threading.Tasks;
+
+namespace Borepin.PageModel
+{
+    class TestPageModel : PageModelBase
+    {
+        #region Contructors
+        public TestPageModel(INavigationService navigationService) : base(navigationService)
+        {
+
+        }
+        #endregion
+
+        #region Data
+        public override async Task<bool> LoadData()
+        {
+            await Task.Delay(3000);
+
+            IsBusy = false;
+            return await Task.FromResult(true);
+        }
+        #endregion
+
+        #region INavigationService
+        public override void OnNavigatedFrom(INavigationParameters parameters)
+        {
+
+        }
+
+        public override void OnNavigatedTo(INavigationParameters parameters)
+        {
+            IsBusy = true;
+            Task.Run(LoadData);
+        }
+        #endregion
+    }
+}
diff --git a/Borepin/Borepin/View/IsBusyView.xaml b/Borepin/Borepin/View/IsBusyView.xaml
new file mode 100644
index 0000000..2b7601c
--- /dev/null
+++ b/Borepin/Borepin/View/IsBusyView.xaml
@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ContentView xmlns="http://xamarin.com/schemas/2014/forms" 
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Borepin.View.IsBusyView">
+  <ContentView.Content>
+      <StackLayout>
+          <Label Text="IsBusy" />
+      </StackLayout>
+  </ContentView.Content>
+</ContentView>
\ No newline at end of file
diff --git a/Borepin/Borepin/View/IsBusyView.xaml.cs b/Borepin/Borepin/View/IsBusyView.xaml.cs
new file mode 100644
index 0000000..d9b5abf
--- /dev/null
+++ b/Borepin/Borepin/View/IsBusyView.xaml.cs
@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+using Xamarin.Forms;
+using Xamarin.Forms.Xaml;
+
+namespace Borepin.View
+{
+    [XamlCompilation(XamlCompilationOptions.Compile)]
+    public partial class IsBusyView : ContentView
+    {
+        public IsBusyView()
+        {
+            InitializeComponent();
+        }
+    }
+}
\ No newline at end of file
diff --git a/FabAccessAPI/Machines.cs b/FabAccessAPI/Machines.cs
index 4739a5c..0966b62 100644
--- a/FabAccessAPI/Machines.cs
+++ b/FabAccessAPI/Machines.cs
@@ -113,6 +113,22 @@ namespace FabAccessAPI
             return writeCap.Use();
         }
 
+        /// <summary>
+        /// Try to get a GiveBack capability for a machine.
+        /// </summary>
+        /// <returns>Capability to give back the machine or null</returns>
+        /// <exception cref="UnauthorizedException"></exception>
+        public Task<Schema.Machine.WriteInterface.IGiveBack> GetGiveBack()
+        {
+            var writeCap = _machine.Write;
+            if (writeCap == null)
+            {
+                throw new UnauthorizedException();
+            }
+
+            return writeCap.GetGiveBack();
+        }
+
         /// <summary>
         /// Try to reserve a machine. Throws a UnauthorizedException if the user does not have the required
         /// permissions to use this machine.
diff --git a/FabAccessAPI/schema b/FabAccessAPI/schema
index 4adb053..2dc488d 160000
--- a/FabAccessAPI/schema
+++ b/FabAccessAPI/schema
@@ -1 +1 @@
-Subproject commit 4adb05341763b96a43440a6a96e0d9959ba71e89
+Subproject commit 2dc488d13b2a8eaa743fb759b4929d50843ccb23