MainWindow.xaml

<Window x:Class="SimpleHmi.Views.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Converters="clr-namespace:SimpleHmi.Converters"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:vm="clr-namespace:SimpleHmi.ViewModels"
        Title="MainWindow"
        Width="525"
        Height="350"
        mc:Ignorable="d">
    <Window.Resources>
        <Converters:BooleanToBrushConverter x:Key="BooleanToBrushConverter" />
    </Window.Resources>
    <Window.DataContext>
        <vm:MainWindowViewModel />
    </Window.DataContext>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*" />
            <RowDefinition Height="auto" />
        </Grid.RowDefinitions>
        <TextBlock Width="117"
                   Height="17"
                   Margin="11,13,0,0"
                   HorizontalAlignment="Left"
                   VerticalAlignment="Top"
                   Text="Ip address"
                   TextWrapping="Wrap" />
        <TextBox Width="117"
                 Height="28"
                 Margin="11,35,0,0"
                 HorizontalAlignment="Left"
                 VerticalAlignment="Top"
                 Text="{Binding IpAddress}"
                 TextWrapping="Wrap" />
        <Button Width="90"
                Height="28"
                Margin="144,35,0,0"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                Command="{Binding ConnectCommand,
                                  Mode=OneWay}"
                Content="Connect" />
        <Button Width="90"
                Height="28"
                Margin="249,35,0,0"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                Command="{Binding DisconnectCommand,
                                  Mode=OneWay}"
                Content="Disconnect" />
        <Ellipse Width="19"
                 Height="18"
                 Margin="29,107,0,0"
                 HorizontalAlignment="Left"
                 VerticalAlignment="Top"
                 Fill="{Binding HighLimit,
                                Converter={StaticResource BooleanToBrushConverter}}"
                 Stroke="Black" />
        <TextBlock Width="117"
                   Height="17"
                   Margin="53,108,0,0"
                   HorizontalAlignment="Left"
                   VerticalAlignment="Top"
                   Text="High limit"
                   TextWrapping="Wrap" />
        <Ellipse Width="19"
                 Height="18"
                 Margin="29,136,0,0"
                 HorizontalAlignment="Left"
                 VerticalAlignment="Top"
                 Fill="{Binding LowLimit,
                                Converter={StaticResource BooleanToBrushConverter}}"
                 Stroke="Black" />
        <TextBlock Width="117"
                   Height="17"
                   Margin="53,137,0,0"
                   HorizontalAlignment="Left"
                   VerticalAlignment="Top"
                   Text="Low limit"
                   TextWrapping="Wrap" />
        <ProgressBar Width="145"
                     Height="18"
                     Margin="27,200,0,0"
                     HorizontalAlignment="Left"
                     VerticalAlignment="Top"
                     Value="{Binding TankLevel}" />
        <TextBlock Width="69"
                   Height="17"
                   Margin="27,183,0,0"
                   HorizontalAlignment="Left"
                   VerticalAlignment="Top"
                   Text="Filling level:"
                   TextWrapping="Wrap" />
        <TextBlock Width="61"
                   Height="17"
                   Margin="96,183,0,0"
                   HorizontalAlignment="Left"
                   VerticalAlignment="Top"
                   Text="{Binding TankLevel,
                                  StringFormat={}{0}%}"
                   TextWrapping="Wrap" />
        <Ellipse Width="19"
                 Height="18"
                 Margin="183,200,0,0"
                 HorizontalAlignment="Left"
                 VerticalAlignment="Top"
                 Fill="{Binding PumpState,
                                Converter={StaticResource BooleanToBrushConverter}}"
                 Stroke="Black" />
        <TextBlock Width="117"
                   Height="17"
                   Margin="207,201,0,0"
                   HorizontalAlignment="Left"
                   VerticalAlignment="Top"
                   Text="Pump state"
                   TextWrapping="Wrap" />
        <Button Width="110"
                Height="31"
                Margin="339,94,0,0"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                Command="{Binding StartCommand,
                                  Mode=OneWay}"
                Content="Start" />
        <Button Width="110"
                Height="31"
                Margin="339,133,0,0"
                HorizontalAlignment="Left"
                VerticalAlignment="Top"
                Command="{Binding StopCommand,
                                  Mode=OneWay}"
                Content="Stop" />
        <StatusBar Grid.Row="1">
            <TextBlock Text="{Binding ConnectionState, StringFormat=Connection state: {0}}" />
            <Separator />
            <TextBlock Text="{Binding ScanTime, StringFormat=ScanTime {0}}" />
        </StatusBar>
    </Grid>
</Window>