fix(s7): numeric TSAP loads in form, shared TSAP conflict error, Test Connect read detects PUT/GET disabled, pin Int32 ms rounding (#632 #638)

Claude-Session: https://claude.ai/code/session_01Ef2ozxS7QPanGT8uoATbTe

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.Contracts/S7DriverOptions.cs

@@ -56,6 +56,7 @@ public sealed class S7DriverOptions
     ///     <c>"0100"</c>, <c>"0x0100"</c>). Null/blank keeps S7.Net's per-CPU default (<c>01.00</c>).
     ///     Needed for CPUs / gateways that reserve connection resources by TSAP (S7-400H, CP343, LOGO!).
     /// </summary>
+    [System.Text.Json.Serialization.JsonConverter(typeof(S7TsapJsonConverter))]
     public string? LocalTsap { get; init; }
 
     /// <summary>
@@ -63,6 +64,7 @@ public sealed class S7DriverOptions
     ///     (e.g. <c>"03.01"</c> = S7-basic resource, rack 0 slot 1). Null/blank keeps the slot-derived default.
     ///     Mutually exclusive with <see cref="ConnectionType"/>.
     /// </summary>
+    [System.Text.Json.Serialization.JsonConverter(typeof(S7TsapJsonConverter))]
     public string? RemoteTsap { get; init; }
 
     /// <summary>
@@ -72,6 +74,11 @@ public sealed class S7DriverOptions
     /// </summary>
     public S7ConnectionType? ConnectionType { get; init; }
 
+    /// <summary>The authoring/load error for setting both <see cref="RemoteTsap"/> and <see cref="ConnectionType"/>; shared by the factory and the AdminUI form so they never disagree.</summary>
+    public const string TsapConflictDetail =
+        "sets both RemoteTsap and ConnectionType; ConnectionType only fills the first byte of the " +
+        "slot-derived remote TSAP, so choose one.";
+
     /// <summary>Connect + per-operation timeout.</summary>
     public TimeSpan Timeout { get; init; } = TimeSpan.FromSeconds(5);
 
@@ -160,6 +167,31 @@ public sealed class S7DriverOptions
     public const int DefaultSpanReadMaxSpanBytes = 220;
 }
 
+/// <summary>
+///     Reads a TSAP as either hex text (<c>"03.01"</c>) or a JSON number (<c>769</c>, the form the driver
+///     factory also accepts) and always writes the hex text. Without it a numeric TSAP would fail to bind to
+///     the string property, and a typed consumer (the AdminUI form, the Test Connect probe) would fall back
+///     to defaults — a form Save would then silently erase the authored config.
+/// </summary>
+public sealed class S7TsapJsonConverter : System.Text.Json.Serialization.JsonConverter<string?>
+{
+    /// <inheritdoc />
+    public override string? Read(ref System.Text.Json.Utf8JsonReader reader, Type typeToConvert, System.Text.Json.JsonSerializerOptions options)
+    {
+        if (reader.TokenType == System.Text.Json.JsonTokenType.Null) return null;
+        if (reader.TokenType == System.Text.Json.JsonTokenType.Number && reader.TryGetUInt16(out var n))
+            return $"{n >> 8:X2}.{n & 0xFF:X2}";
+        if (reader.TokenType == System.Text.Json.JsonTokenType.String) return reader.GetString();
+        throw new System.Text.Json.JsonException("S7 TSAP must be hex text such as \"03.01\" or a 16-bit number.");
+    }
+
+    /// <inheritdoc />
+    public override void Write(System.Text.Json.Utf8JsonWriter writer, string? value, System.Text.Json.JsonSerializerOptions options)
+    {
+        if (value is null) writer.WriteNullValue(); else writer.WriteStringValue(value);
+    }
+}
+
 public sealed class S7ProbeOptions
 {
     /// <summary>Gets or sets a value indicating whether probing is enabled.</summary>

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7Driver.cs

@@ -2335,7 +2335,7 @@ public sealed class S7Driver
     ///     no typed error code for it, so the inner message is the only discriminator
     ///     S7.Net exposes.
     /// </summary>
-    private static bool IsAccessDenied(PlcException pex)
+    internal static bool IsAccessDenied(PlcException pex)
     {
         for (Exception? e = pex; e is not null; e = e.InnerException)
         {

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7DriverFactoryExtensions.cs

@@ -96,8 +96,7 @@ public static class S7DriverFactoryExtensions
             : ParseEnum<S7ConnectionType>(dto.ConnectionType, driverInstanceId, "ConnectionType");
         if (remoteTsap is not null && connectionType is not null)
             throw new InvalidOperationException(
-                $"S7 driver config for '{driverInstanceId}' sets both RemoteTsap and ConnectionType; " +
-                "ConnectionType only fills the first byte of the slot-derived remote TSAP, so choose one.");
+                $"S7 driver config for '{driverInstanceId}' {S7DriverOptions.TsapConflictDetail}");
 
         return new S7DriverOptions
         {

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7DriverProbe.cs

@@ -80,7 +80,15 @@ public sealed class S7DriverProbe : IDriverProbe
             sw.Stop();
 
             if (plc.IsConnected)
+            {
+                // A handshake alone passes on a CPU with PUT/GET disabled (S7-1200/1500 default) — every
+                // later read would fail. One minimal read proves data access.
+                if (await CheckDataAccessAsync(
+                        t => plc.ReadBytesAsync(global::S7.Net.DataType.Memory, 0, 0, 2, t), handshakeCts.Token)
+                    is { } denied)
+                    return denied;
                 return new(true, $"S7 connected (CPU {opts.CpuType}, PDU {plc.MaxPDUSize} bytes)", sw.Elapsed);
+            }
 
             return new(false, $"Reachable at {host}:{port} but S7 handshake failed: not connected", null);
         }
@@ -104,6 +112,38 @@ public sealed class S7DriverProbe : IDriverProbe
         }
     }
 
+    /// <summary>
+    ///     Runs one minimal read after the handshake. Returns null when data access works — including when the
+    ///     CPU merely rejects that particular address (MB0 not present / out of range: the connection is fine).
+    ///     PUT/GET-disabled yields the actionable message; any other fault is a probe failure with its message.
+    /// </summary>
+    /// <param name="read">The minimal read.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>A failure result, or null on success.</returns>
+    internal static async Task<DriverProbeResult?> CheckDataAccessAsync(Func<CancellationToken, Task<byte[]>> read, CancellationToken ct)
+    {
+        try
+        {
+            await read(ct).ConfigureAwait(false);
+            return null;
+        }
+        catch (OperationCanceledException) { throw; }
+        catch (PlcException pex) when (S7Driver.IsAccessDenied(pex))
+        {
+            return new(false,
+                "S7 connected but data access is denied — enable PUT/GET communication in TIA Portal " +
+                $"(Protection & Security) for this CPU. PLC reported: {pex.Message}", null);
+        }
+        catch (PlcException pex) when (pex.ErrorCode == ErrorCode.ReadData)
+        {
+            return null; // address not available on this CPU — not a connection problem
+        }
+        catch (Exception ex)
+        {
+            return new(false, $"S7 connected but a test read failed: {ex.Message}", null);
+        }
+    }
+
     private static (string host, int port) ExtractTarget(S7DriverOptions opts)
         => (opts.Host, opts.Port);
 }

src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7ValueCodecs.cs

@@ -287,6 +287,8 @@ internal static class S7ValueCodecs
         }
     }
 
+    // Fractional input is rounded (Convert.ToInt64, banker's), matching the driver's existing Int32 write
+    // path (BoxValueForWrite → Convert.ToInt32). "Refused, not rounded" applies to S5TIME's time-base grid.
     private static long ToMilliseconds(object? value, string type)
     {
         try { return value is TimeSpan ts ? (long)ts.TotalMilliseconds : Convert.ToInt64(value, System.Globalization.CultureInfo.InvariantCulture); }