Add Sharp7Plc.ToString()

2.0 Release

.github/workflows/release.yml

@@ -14,7 +14,7 @@ jobs:
 
     runs-on: windows-latest
     env:
-      version: 2.0.${{ github.run_number }}${{ github.ref == 'refs/heads/master' && '' || '-prerelease' }}
+      version: 2.0.${{ github.run_number }}${{ github.ref != 'refs/heads/master' && '-prerelease' || '' }}
 
     steps:
     - uses: actions/checkout@v2
@@ -26,8 +26,6 @@ jobs:
       run: nuget install NUnit.ConsoleRunner -Version 3.17.0 -DirectDownload -OutputDirectory .
     - name: Install dependencies
       run: dotnet restore
-    - name: Install dependencies
-      run: dotnet restore
     - name: Build
       run: dotnet build --configuration Release --no-restore /p:version=${{ env.version }}
     - name: Tests

README.md

@@ -1,6 +1,6 @@
 # Sharp7Reactive
 
-[![.NET Core Build](https://github.com/evopro-ag/Sharp7Reactive/actions/workflows/dotnet-core.yml/badge.svg)](https://github.com/evopro-ag/Sharp7Reactive/actions/workflows/dotnet-core.yml)
+[![Release](https://github.com/evopro-ag/Sharp7Reactive/actions/workflows/release.yml/badge.svg?branch=master)](https://github.com/evopro-ag/Sharp7Reactive/actions/workflows/release.yml)
 ![Licence](https://img.shields.io/github/license/evopro-ag/Sharp7Reactive.svg)
 [![Nuget Version](https://img.shields.io/nuget/v/Sharp7.Rx.svg)](https://www.nuget.org/packages/Sharp7.Rx/)
 

Sharp7.Rx.Tests/Sharp7.Rx.Tests.csproj

@@ -15,9 +15,9 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="DeepEqual" Version="4.2.1" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="NUnit" Version="4.0.1" />
+    <PackageReference Include="DeepEqual" Version="5.1.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
+    <PackageReference Include="NUnit" Version="4.1.0" />
     <PackageReference Include="Shouldly" Version="4.2.1" />
   </ItemGroup>
 

Sharp7.Rx/Enums/CpuType.cs

@@ -1,9 +0,0 @@
-namespace Sharp7.Rx.Enums;
-
-internal enum CpuType
-{
-    S7_300,
-    S7_400,
-    S7_1200,
-    S7_1500
-}

Sharp7.Rx/S7ErrorCodes.cs

@@ -1,7 +1,5 @@
 #nullable enable
 
-using System.Diagnostics.CodeAnalysis;
-
 namespace Sharp7.Rx;
 
 public static class S7ErrorCodes
@@ -22,7 +20,7 @@ public static class S7ErrorCodes
         {0x900000, "This happens when the DB is not long enough."},
         {
             0x40000, """
-                     This error occurs when the DB is "optimized" or "PUT/GET communication" is not enabled.
+                     This can happen when the cpu MPI address or rack is wrong, the DB is "optimized", or "PUT/GET communication" is not enabled.
                      See https://snap7.sourceforge.net/snap7_client.html#target_compatibility.
                      """
         }

Sharp7.Rx/Sharp7.Rx.csproj

@@ -9,7 +9,9 @@
     <AnalysisLevel>latest-Recommended</AnalysisLevel>
 
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <AllowedOutputExtensionsInPackageBuildOutputFolder>$(AllowedOutputExtensionsInPackageBuildOutputFolder);.pdb</AllowedOutputExtensionsInPackageBuildOutputFolder>
+
     <Authors>evopro system engineering AG</Authors>
     <Company>evopro system engineering AG</Company>
     <Description>Reactive framework for Sharp7, the Ethernet S7 PLC communication suite. Handling RFC1006 connections to Siemens S7 300, 1200 and 1500.</Description>
@@ -23,16 +25,17 @@
        CA1848: For improved performance, use the LoggerMessage delegates
        CA2254: The logging message template should not vary between calls
        CA1859: Change type of field 'xxx' from interface to type for performance reasons
+       CS1591: Missing XML comment for publicly visible type or member
     -->
-    <NoWarn>$(NoWarn);CA1848;CA2254;CA1859</NoWarn>
+    <NoWarn>$(NoWarn);CA1848;CA2254;CA1859;CS1591</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="JetBrains.Annotations" Version="2023.3.0" PrivateAssets="All" />
+    <PackageReference Include="JetBrains.Annotations" Version="2024.2.0" PrivateAssets="All" />
     <PackageReference Include="Microsoft.Extensions.Logging" Version="8.0.0" />
     <PackageReference Include="Sharp7" Version="1.1.84" />
     <PackageReference Include="System.Interactive" Version="6.0.1" />
-    <PackageReference Include="System.Reactive" Version="6.0.0" />
+    <PackageReference Include="System.Reactive" Version="6.0.1" />
   </ItemGroup>
 
   <ItemGroup>

Sharp7.Rx/Sharp7Connector.cs

@@ -10,7 +10,7 @@ using Sharp7.Rx.Settings;
 
 namespace Sharp7.Rx;
 
-internal class Sharp7Connector: IDisposable
+internal class Sharp7Connector : IDisposable
 {
     private readonly BehaviorSubject<ConnectionState> connectionStateSubject = new(Enums.ConnectionState.Initial);
     private readonly int cpuSlotNr;
@@ -35,16 +35,21 @@ internal class Sharp7Connector: IDisposable
         rackNr = settings.RackNumber;
 
         ReconnectDelay = TimeSpan.FromSeconds(5);
+
+        ConnectionIdentifier = $"{ipAddress}:{port} Cpu {cpuSlotNr} Rack {rackNr}";
     }
 
     public IObservable<ConnectionState> ConnectionState => connectionStateSubject.DistinctUntilChanged().AsObservable();
+    public ConnectionState CurrentConnectionState => connectionStateSubject.Value;
 
     public ILogger Logger { get; set; }
 
-    public TimeSpan ReconnectDelay { get; set; }
+    private string ConnectionIdentifier { get; }
 
     private bool IsConnected => connectionStateSubject.Value == Enums.ConnectionState.Connected;
 
+    private TimeSpan ReconnectDelay { get; }
+
     public void Dispose()
     {
         Dispose(true);
@@ -67,13 +72,13 @@ internal class Sharp7Connector: IDisposable
             else
             {
                 var errorText = EvaluateErrorCode(errorCode);
-                Logger.LogError("Failed to establish initial connection: {Error}", errorText);
+                Logger.LogError("Failed to establish initial connection to {Connection}: {Error}", ConnectionIdentifier, errorText);
             }
         }
         catch (Exception ex)
         {
             connectionStateSubject.OnNext(Enums.ConnectionState.ConnectionLost);
-            Logger.LogError(ex, "Failed to establish initial connection.");
+            Logger.LogError(ex, "Failed to establish initial connection ro {Connection}.", ConnectionIdentifier);
         }
 
         return false;
@@ -112,12 +117,11 @@ internal class Sharp7Connector: IDisposable
         return buffers.ToDictionary(arg => arg.VariableName, arg => arg.Buffer);
     }
 
-    public Task InitializeAsync()
+    public void InitializeAsync()
     {
         try
         {
-            sharp7 = new S7Client();
-            sharp7.PLCPort = port;
+            sharp7 = new S7Client {PLCPort = port};
 
             var subscription =
                 ConnectionState
@@ -125,17 +129,15 @@ internal class Sharp7Connector: IDisposable
                     .Take(1)
                     .SelectMany(_ => Reconnect())
                     .RepeatAfterDelay(ReconnectDelay)
-                    .LogAndRetry(Logger, "Error while reconnecting to S7.")
+                    .LogAndRetry(Logger, $"Error while reconnecting to {ConnectionIdentifier}.")
                     .Subscribe();
 
             disposables.Add(subscription);
         }
         catch (Exception ex)
         {
-            Logger?.LogError(ex, "S7 driver could not be initialized");
+            Logger?.LogError(ex, "S7 driver for {Connection} could not be initialized", ConnectionIdentifier);
         }
-
-        return Task.FromResult(true);
     }
 
     public async Task<byte[]> ReadBytes(Operand operand, ushort startByteAddress, ushort bytesToRead, ushort dbNo, CancellationToken token)
@@ -149,11 +151,13 @@ internal class Sharp7Connector: IDisposable
             await Task.Factory.StartNew(() => sharp7.ReadArea(operand.ToArea(), dbNo, startByteAddress, bytesToRead, S7WordLength.Byte, buffer), token, TaskCreationOptions.None, scheduler);
         token.ThrowIfCancellationRequested();
 
-        EnsureSuccessOrThrow(result, $"Error reading {operand}{dbNo}:{startByteAddress}->{bytesToRead}");
+        EnsureSuccessOrThrow(result, $"Error reading {operand}{dbNo}:{startByteAddress} ({bytesToRead} bytes)");
 
         return buffer;
     }
 
+    public override string ToString() => ConnectionIdentifier;
+
     public async Task WriteBit(Operand operand, ushort startByteAddress, byte bitAdress, bool value, ushort dbNo, CancellationToken token)
     {
         EnsureConnectionValid();
@@ -175,7 +179,7 @@ internal class Sharp7Connector: IDisposable
         var result = await Task.Factory.StartNew(() => sharp7.WriteArea(operand.ToArea(), dbNo, startByteAddress, bytesToWrite, S7WordLength.Byte, data), token, TaskCreationOptions.None, scheduler);
         token.ThrowIfCancellationRequested();
 
-        EnsureSuccessOrThrow(result, $"Error writing {operand}{dbNo}:{startByteAddress}.{data.Length}");
+        EnsureSuccessOrThrow(result, $"Error writing {operand}{dbNo}:{startByteAddress} ({data.Length} bytes)");
     }
 
 
@@ -222,18 +226,18 @@ internal class Sharp7Connector: IDisposable
             throw new InvalidOperationException("Plc is not connected");
     }
 
-    private void EnsureSuccessOrThrow(int result, string message)
+    private void EnsureSuccessOrThrow(int errorCode, string message)
     {
-        if (result == 0) return;
+        if (errorCode == 0) return;
 
-        var errorText = EvaluateErrorCode(result);
+        var errorText = EvaluateErrorCode(errorCode);
         var completeMessage = $"{message}: {errorText}";
 
-        var additionalErrorText = S7ErrorCodes.GetAdditionalErrorText(result);
+        var additionalErrorText = S7ErrorCodes.GetAdditionalErrorText(errorCode);
         if (additionalErrorText != null)
             completeMessage += Environment.NewLine + additionalErrorText;
 
-        throw new S7CommunicationException(completeMessage, result, errorText);
+        throw new S7CommunicationException(completeMessage, errorCode, errorText);
     }
 
     private string EvaluateErrorCode(int errorCode)
@@ -245,7 +249,6 @@ internal class Sharp7Connector: IDisposable
             throw new InvalidOperationException("S7 driver is not initialized.");
 
         var errorText = $"0x{errorCode:X}, {sharp7.ErrorText(errorCode)}";
-        Logger?.LogError($"S7 Error {errorText}");
 
         if (S7ErrorCodes.AssumeConnectionLost(errorCode))
             SetConnectionLostState();

Sharp7.Rx/Sharp7Plc.cs

@@ -28,7 +28,7 @@ public class Sharp7Plc : IPlc
     private readonly ConcurrentSubjectDictionary<string, byte[]> multiVariableSubscriptions = new(StringComparer.InvariantCultureIgnoreCase);
     private readonly List<long> performanceCounter = new(1000);
     private readonly PlcConnectionSettings plcConnectionSettings;
-    private readonly CacheVariableNameParser variableNameParser = new CacheVariableNameParser(new VariableNameParser());
+    private readonly CacheVariableNameParser variableNameParser = new(new VariableNameParser());
     private bool disposed;
     private int initialized;
 
@@ -37,10 +37,10 @@ public class Sharp7Plc : IPlc
 
     /// <summary>
     /// </summary>
-    /// <param name="ipAddress"></param>
-    /// <param name="rackNumber"></param>
-    /// <param name="cpuMpiAddress"></param>
-    /// <param name="port"></param>
+    /// <param name="ipAddress">IP address of S7.</param>
+    /// <param name="rackNumber">See <see href="https://github.com/fbarresi/Sharp7/wiki/Connection#rack-and-slot">Sharp7 wiki</see></param>
+    /// <param name="cpuMpiAddress">See <see href="https://github.com/fbarresi/Sharp7/wiki/Connection#rack-and-slot">Sharp7 wiki</see></param>
+    /// <param name="port">TCP port for communication</param>
     /// <param name="multiVarRequestCycleTime">
     ///     <para>
     ///         Polling interval for multi variable read from PLC.
@@ -90,10 +90,6 @@ public class Sharp7Plc : IPlc
     ///     Create an Observable for a given variable. Multiple notifications are automatically combined into a multi-variable subscription to
     ///     reduce network trafic and PLC workload.
     /// </summary>
-    /// <typeparam name="TValue"></typeparam>
-    /// <param name="variableName"></param>
-    /// <param name="transmissionMode"></param>
-    /// <returns></returns>
     public IObservable<TValue> CreateNotification<TValue>(string variableName, TransmissionMode transmissionMode)
     {
         return Observable.Create<TValue>(observer =>
@@ -105,9 +101,13 @@ public class Sharp7Plc : IPlc
             disposableContainer.AddDisposableTo(disp);
 
             var observable =
-                // Read variable with GetValue first.
-                // This will propagate any errors due to reading from invalid addresses.
-                Observable.FromAsync(() => GetValue<TValue>(variableName))
+                ConnectionState
+                    // Wait for connection to be established
+                    .FirstAsync(c => c == Enums.ConnectionState.Connected)
+                    // Read variable with GetValue first.
+                    // This will propagate any errors due to reading from invalid addresses.
+                    .SelectMany(_ => GetValue<TValue>(variableName))
+                    // Output results from read loop
                     .Concat(
                         disposableContainer.Observable
                             .Select(bytes => ValueConverter.ReadFromBuffer<TValue>(bytes, address))
@@ -124,12 +124,28 @@ public class Sharp7Plc : IPlc
     }
 
     /// <summary>
-    ///     Read PLC variable as generic variable.
+    ///     Creates an observable of object for a variable.
+    ///     The return type is automatically infered from the variable name.
+    /// </summary>
+    /// <returns>The return type is infered from the variable name.</returns>
+    public IObservable<object> CreateNotification(string variableName, TransmissionMode transmissionMode)
+    {
+        var address = variableNameParser.Parse(variableName);
+        var clrType = address.GetClrType();
+
+        var genericCreateNotification = createNotificationMethod!.MakeGenericMethod(clrType);
+
+        var genericNotification = genericCreateNotification.Invoke(this, [variableName, transmissionMode]);
+
+        return SignatureConverter.ConvertToObjectObservable(genericNotification, clrType);
+    }
+
+    /// <summary>
+    ///     Read PLC variable as generic variable.
+    ///     <para>
+    ///         The method will fail with a <see cref="InvalidOperationException" />, if <see cref="ConnectionState" /> is not <see cref="ConnectionState.Connected" />.
+    ///     </para>
     /// </summary>
-    /// <typeparam name="TValue"></typeparam>
-    /// <param name="variableName"></param>
-    /// <param name="token"></param>
-    /// <returns></returns>
     public async Task<TValue> GetValue<TValue>(string variableName, CancellationToken token = default)
     {
         var address = ParseAndVerify(variableName, typeof(TValue));
@@ -141,9 +157,10 @@ public class Sharp7Plc : IPlc
     /// <summary>
     ///     Read PLC variable as object.
     ///     The return type is automatically infered from the variable name.
+    ///     <para>
+    ///         The method will fail with a <see cref="InvalidOperationException" />, if <see cref="ConnectionState" /> is not <see cref="ConnectionState.Connected" />.
+    ///     </para>
     /// </summary>
-    /// <param name="variableName"></param>
-    /// <param name="token"></param>
     /// <returns>The actual return type is infered from the variable name.</returns>
     public async Task<object> GetValue(string variableName, CancellationToken token = default)
     {
@@ -164,12 +181,10 @@ public class Sharp7Plc : IPlc
 
     /// <summary>
     ///     Write value to the PLC.
+    ///     <para>
+    ///         The method will fail with a <see cref="InvalidOperationException" />, if <see cref="ConnectionState" /> is not <see cref="ConnectionState.Connected" />.
+    ///     </para>
     /// </summary>
-    /// <typeparam name="TValue"></typeparam>
-    /// <param name="variableName"></param>
-    /// <param name="value"></param>
-    /// <param name="token"></param>
-    /// <returns></returns>
     public async Task SetValue<TValue>(string variableName, TValue value, CancellationToken token = default)
     {
         var address = ParseAndVerify(variableName, typeof(TValue));
@@ -192,30 +207,11 @@ public class Sharp7Plc : IPlc
             }
             finally
             {
-                ArrayPool<byte>.Shared.Return(buffer);
+                arrayPool.Return(buffer);
             }
         }
     }
 
-    /// <summary>
-    ///     Creates an observable of object for a variable.
-    ///     The return type is automatically infered from the variable name.
-    /// </summary>
-    /// <param name="variableName"></param>
-    /// <param name="transmissionMode"></param>
-    /// <returns>The return type is infered from the variable name.</returns>
-    public IObservable<object> CreateNotification(string variableName, TransmissionMode transmissionMode)
-    {
-        var address = variableNameParser.Parse(variableName);
-        var clrType = address.GetClrType();
-
-        var genericCreateNotification = createNotificationMethod!.MakeGenericMethod(clrType);
-
-        var genericNotification = genericCreateNotification.Invoke(this, [variableName, transmissionMode]);
-
-        return SignatureConverter.ConvertToObjectObservable(genericNotification, clrType);
-    }
-
     /// <summary>
     ///     Trigger PLC connection and start notification loop.
     ///     <para>
@@ -224,26 +220,37 @@ public class Sharp7Plc : IPlc
     /// </summary>
     /// <returns>Always true</returns>
     [Obsolete($"Use {nameof(InitializeConnection)} or {nameof(TriggerConnection)}.")]
-    public async Task<bool> InitializeAsync()
+    public Task<bool> InitializeAsync()
     {
-        await TriggerConnection();
-        return true;
+        TriggerConnection();
+        return Task.FromResult(true);
     }
 
 
     /// <summary>
-    ///     Initialize PLC connection and wait for connection to be established.
+    ///     Initialize PLC connection and wait for connection to be established (<see cref="ConnectionState" /> is <see cref="ConnectionState.Connected" />).
     /// </summary>
     /// <param name="token"></param>
     /// <returns></returns>
-    public async Task InitializeConnection(CancellationToken token = default) => await DoInitializeConnection(true, token);
+    public async Task InitializeConnection(CancellationToken token = default)
+    {
+        DoInitializeConnection();
+        await s7Connector.ConnectionState
+            .FirstAsync(c => c == Enums.ConnectionState.Connected)
+            .ToTask(token);
+    }
+
+    public override string ToString() => $"S7 {s7Connector} ({s7Connector.CurrentConnectionState})";
 
     /// <summary>
     ///     Initialize PLC and trigger connection. This method will not wait for the connection to be established.
+    ///     <para>
+    ///         Without an established connection, it is safe to call <see cref="CreateNotification" />, but <see cref="GetValue{TValue}" />
+    ///         and <see cref="SetValue{TValue}" /> will fail.
+    ///     </para>
     /// </summary>
-    /// <param name="token"></param>
     /// <returns></returns>
-    public async Task TriggerConnection(CancellationToken token = default) => await DoInitializeConnection(false, token);
+    public void TriggerConnection() => DoInitializeConnection();
 
     protected virtual void Dispose(bool disposing)
     {
@@ -266,11 +273,12 @@ public class Sharp7Plc : IPlc
         }
     }
 
-    private async Task DoInitializeConnection(bool waitForConnection, CancellationToken token)
+    private void DoInitializeConnection()
     {
-        if (Interlocked.Exchange(ref initialized, 1) == 1) return;
+        if (Interlocked.Exchange(ref initialized, 1) == 1)
+            return;
 
-        await s7Connector.InitializeAsync();
+        s7Connector.InitializeAsync();
 
         // Triger connection.
         // The initial connection might fail. In this case a reconnect is initiated.
@@ -281,16 +289,11 @@ public class Sharp7Plc : IPlc
             {
                 await s7Connector.Connect();
             }
-            catch (Exception e)
+            catch (Exception)
             {
-                Logger?.LogError(e, "Intiial PLC connection failed.");
+                // Ignore. Exception is logged in the connector
             }
-        }, token);
-
-        if (waitForConnection)
-            await s7Connector.ConnectionState
-                .FirstAsync(c => c == Enums.ConnectionState.Connected)
-                .ToTask(token);
+        });
 
         StartNotificationLoop();
     }
@@ -329,9 +332,12 @@ public class Sharp7Plc : IPlc
 
     private void PrintAndResetPerformanceStatistik()
     {
-        if (performanceCounter.Count == performanceCounter.Capacity)
+        if (performanceCounter.Count != performanceCounter.Capacity) return;
+
+        if (Logger.IsEnabled(LogLevel.Trace))
         {
             var average = performanceCounter.Average();
+
             var min = performanceCounter.Min();
             var max = performanceCounter.Max();
 
@@ -340,8 +346,9 @@ public class Sharp7Plc : IPlc
                              performanceCounter.Capacity, min, max, average,
                              multiVariableSubscriptions.ExistingKeys.Count(),
                              MultiVarRequestMaxItems);
-            performanceCounter.Clear();
         }
+
+        performanceCounter.Clear();
     }
 
     private void StartNotificationLoop()
@@ -355,16 +362,11 @@ public class Sharp7Plc : IPlc
                 .FirstAsync(states => states == Enums.ConnectionState.Connected)
                 .SelectMany(_ => GetAllValues(s7Connector))
                 .RepeatAfterDelay(MultiVarRequestCycleTime)
-                .LogAndRetryAfterDelay(Logger, MultiVarRequestCycleTime, "Error while getting batch notifications from plc")
+                .LogAndRetryAfterDelay(Logger, MultiVarRequestCycleTime, $"Error while getting batch notifications from {s7Connector}")
                 .Subscribe();
 
         if (Interlocked.CompareExchange(ref notificationSubscription, subscription, null) != null)
             // Subscription has already been created (race condition). Dispose new subscription.
             subscription.Dispose();
     }
-
-    ~Sharp7Plc()
-    {
-        Dispose(false);
-    }
 }

Sharp7.Rx/VariableNameParser.cs

@@ -120,7 +120,7 @@ internal class VariableNameParser : IVariableNameParser
             {
                 if (defaultValue.HasValue)
                     return defaultValue.Value;
-                throw new InvalidS7AddressException($"Variable of type {type} must have a length set \"{input}\"", input);
+                throw new InvalidS7AddressException($"Variable of type {type} must have a length set. Example \"db12.byte10.3\", found \"{input}\"", input);
             }
 
             if (!ushort.TryParse(match.Groups["bitOrLength"].Value, out var result))
@@ -132,7 +132,7 @@ internal class VariableNameParser : IVariableNameParser
         byte GetBit()
         {
             if (!match.Groups["bitOrLength"].Success)
-                throw new InvalidS7AddressException($"Variable of type {type} must have a bit number set \"{input}\"", input);
+                throw new InvalidS7AddressException($"Variable of type {type} must have a bit number set. Example \"db12.bit10.3\", found \"{input}\"", input);
 
             if (!byte.TryParse(match.Groups["bitOrLength"].Value, out var result))
                 throw new InvalidS7AddressException($"\"{match.Groups["bitOrLength"].Value}\" is an invalid bit number in \"{input}\"", input);

Sharp7.Rx/linqpad-samples/Create Notification.linq

@@ -23,7 +23,7 @@ await plc.InitializeConnection();
 // create an IObservable
 var observable = plc.CreateNotification<short>($"DB{db}.Int6", Sharp7.Rx.Enums.TransmissionMode.OnChange);
 
-observable.Dump();
+_ = observable.Dump();
 
 for (int i = 0; i < 10; i++)
 {

Sharp7.Rx/linqpad-samples/Establish connection.linq

@@ -20,10 +20,12 @@ using var plc = new Sharp7Plc(ip, rackNumber, cpuMpiAddress);
 // Initialize connection
 await plc.InitializeConnection();
 
-// wait for connection to be established
-await plc.ConnectionState
-	.FirstAsync(c => c == Sharp7.Rx.Enums.ConnectionState.Connected)
-	.ToTask();
+// // Alternative: Trigger connection and wait for ConnectionState == Connected
+// plc.TriggerConnection();
+// // wait for connection to be established
+//await plc.ConnectionState
+//    .FirstAsync(c => c == Sharp7.Rx.Enums.ConnectionState.Connected)
+//    .ToTask();
 
 "Connection established".Dump();
 

Sharp7.Rx/linqpad-samples/Multiple notifications.linq

@@ -16,13 +16,13 @@ var cpuMpiAddress = 0;
 
 using var plc = new Sharp7Plc(ip, rackNumber, cpuMpiAddress);
 
-plc.ConnectionState.Dump();
+_ = plc.ConnectionState.Dump();
 
 await plc.InitializeConnection();
 
 // create an IObservable
-plc.CreateNotification<short>($"DB{db}.Int6", Sharp7.Rx.Enums.TransmissionMode.OnChange).Dump("Int 6");
-plc.CreateNotification<float>($"DB{db}.Real10", Sharp7.Rx.Enums.TransmissionMode.OnChange).Dump("Real 10");
+_ = plc.CreateNotification<short>($"DB{db}.Int6", Sharp7.Rx.Enums.TransmissionMode.OnChange).Dump("Int 6");
+_ = plc.CreateNotification<float>($"DB{db}.Real10", Sharp7.Rx.Enums.TransmissionMode.OnChange).Dump("Real 10");