feat(modbus): resolve equipment-tag refs (read + write) via EquipmentTagRefResolver

2026-06-13 11:12:01 -04:00
parent eaa335d779
commit 232c557985
3 changed files with 128 additions and 4 deletions
@@ -0,0 +1,54 @@
+using System.Text.Json;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus;
+
+/// <summary>Parses an equipment tag's <c>TagConfig</c> JSON (the shape authored by the AdminUI
+/// <c>ModbusTagConfigModel</c>) into a transient <see cref="ModbusTagDefinition"/> whose
+/// <see cref="ModbusTagDefinition.Name"/> equals the reference string itself, so a value the
+/// driver publishes back keys the runtime's forward router correctly.</summary>
+public static class ModbusEquipmentTagParser
+{
+    /// <summary>Attempts to parse an equipment-tag reference into a transient definition.</summary>
+    /// <param name="reference">The equipment tag's TagConfig JSON (also used as the def identity).</param>
+    /// <param name="def">The transient definition when parsing succeeds.</param>
+    /// <returns><see langword="true"/> when <paramref name="reference"/> is a Modbus address object.</returns>
+    public static bool TryParse(string reference, out ModbusTagDefinition def)
+    {
+        def = null!;
+        // Authored tag names never start with '{' (AdminUI name validation), so a leading brace marks an equipment-tag TagConfig blob.
+        if (string.IsNullOrWhiteSpace(reference) || reference[0] != '{') return false;
+        try
+        {
+            using var doc = JsonDocument.Parse(reference);
+            var root = doc.RootElement;
+            if (root.ValueKind != JsonValueKind.Object
+                || !root.TryGetProperty("region", out _)
+                || !root.TryGetProperty("address", out var addr))
+                return false;
+            if (addr.ValueKind != JsonValueKind.Number
+                || !addr.TryGetInt32(out var address)
+                || address < 0 || address > ushort.MaxValue)
+                return false;
+            var region = ReadEnum(root, "region", ModbusRegion.HoldingRegisters);
+            var dataType = ReadEnum(root, "dataType", ModbusDataType.Int16);
+            var byteOrder = ReadEnum(root, "byteOrder", ModbusByteOrder.BigEndian);
+            var bitIndex = (byte)ReadInt(root, "bitIndex");
+            var stringLength = (ushort)ReadInt(root, "stringLength");
+            def = new ModbusTagDefinition(
+                Name: reference, Region: region, Address: (ushort)address, DataType: dataType,
+                Writable: true, ByteOrder: byteOrder, BitIndex: bitIndex, StringLength: stringLength);
+            return true;
+        }
+        catch (JsonException) { return false; }
+        catch (FormatException) { return false; }
+        catch (InvalidOperationException) { return false; }
+    }
+
+    private static TEnum ReadEnum<TEnum>(JsonElement o, string name, TEnum fallback) where TEnum : struct, Enum
+        => o.TryGetProperty(name, out var e) && e.ValueKind == JsonValueKind.String
+           && Enum.TryParse<TEnum>(e.GetString(), ignoreCase: true, out var v) ? v : fallback;
+
+    private static int ReadInt(JsonElement o, string name)
+        => o.TryGetProperty(name, out var e) && e.ValueKind == JsonValueKind.Number
+           && e.TryGetInt32(out var v) ? v : 0;
+}
@@ -34,6 +34,11 @@ public sealed class ModbusDriver

    private readonly Dictionary<string, ModbusTagDefinition> _tagsByName = new(StringComparer.OrdinalIgnoreCase);

+    // Resolves a read/write/subscribe fullReference to a tag definition, bridging the two
+    // authoring models: an authored tag-table entry (by name) OR an equipment tag whose
+    // reference is its raw TagConfig JSON (parsed once via ModbusEquipmentTagParser, cached).
+    private readonly EquipmentTagRefResolver<ModbusTagDefinition> _resolver;
+
    // Last-published value per tag, keyed by FullReference. Used by ShouldPublish to apply
    // the deadband filter. Stored as object so all numeric types share one map; the comparison
    // does a typed cast inside.
@@ -111,6 +116,9 @@ public sealed class ModbusDriver
        _options = options;
        _driverInstanceId = driverInstanceId;
        _logger = logger ?? NullLogger<ModbusDriver>.Instance;
+        _resolver = new EquipmentTagRefResolver<ModbusTagDefinition>(
+            r => _tagsByName.TryGetValue(r, out var t) ? t : null,
+            r => ModbusEquipmentTagParser.TryParse(r, out var d) ? d : null);
        _transportFactory = transportFactory
            ?? (o => new ModbusTcpTransport(
                o.Host, o.Port, o.Timeout, o.AutoReconnect,
@@ -148,7 +156,7 @@ public sealed class ModbusDriver

    private bool ShouldPublish(string tagRef, DataValueSnapshot snapshot)
    {
-        if (!_tagsByName.TryGetValue(tagRef, out var tag) || tag.Deadband is null) return true;
+        if (!_resolver.TryResolve(tagRef, out var tag) || tag.Deadband is null) return true;
        if (snapshot.Value is null) return true;
        // Deadband only applies to numeric scalar types — array / Bool / String publishes
        // unconditionally. Easier to special-case skip than to enumerate the supported types.
@@ -297,7 +305,7 @@ public sealed class ModbusDriver
        for (var i = 0; i < fullReferences.Count; i++)
        {
            if (coalesced.Contains(i)) continue;
-            if (!_tagsByName.TryGetValue(fullReferences[i], out var tag))
+            if (!_resolver.TryResolve(fullReferences[i], out var tag))
            {
                results[i] = new DataValueSnapshot(null, StatusBadNodeIdUnknown, null, now);
                continue;
@@ -711,7 +719,7 @@ public sealed class ModbusDriver
        var eligible = new List<(int Index, string Ref, ModbusTagDefinition Tag)>();
        for (var i = 0; i < fullReferences.Count; i++)
        {
-            if (!_tagsByName.TryGetValue(fullReferences[i], out var tag)) continue;
+            if (!_resolver.TryResolve(fullReferences[i], out var tag)) continue;
            if (tag.CoalesceProhibited) continue;
            if (tag.ArrayCount.HasValue) continue;
            if (tag.Region is not (ModbusRegion.HoldingRegisters or ModbusRegion.InputRegisters)) continue;
@@ -931,7 +939,7 @@ public sealed class ModbusDriver
        for (var i = 0; i < writes.Count; i++)
        {
            var w = writes[i];
-            if (!_tagsByName.TryGetValue(w.FullReference, out var tag))
+            if (!_resolver.TryResolve(w.FullReference, out var tag))
            {
                results[i] = new WriteResult(StatusBadNodeIdUnknown);
                continue;
@@ -1617,6 +1625,7 @@ public sealed class ModbusDriver
        _reprobeCts = null;

        _tagsByName.Clear();
+        _resolver.Clear(); // drop transient equipment-tag parses so a config change re-parses
        _lastPublishedByRef.Clear();
        lock (_lastWrittenLock) _lastWrittenByRef.Clear();
        lock (_autoProhibitedLock) _autoProhibited.Clear();
@@ -0,0 +1,61 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Driver.Modbus;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.Modbus.Tests;
+
+[Trait("Category", "Unit")]
+public class ModbusEquipmentTagTests
+{
+    [Fact]
+    public void Parses_equipment_tagconfig_into_a_transient_definition()
+    {
+        var json = """{"region":"HoldingRegisters","address":40001,"dataType":"UInt16","byteOrder":"BigEndian","bitIndex":0,"stringLength":0}""";
+        ModbusEquipmentTagParser.TryParse(json, out var def).ShouldBeTrue();
+        def!.Name.ShouldBe(json);
+        def.Region.ShouldBe(ModbusRegion.HoldingRegisters);
+        def.Address.ShouldBe((ushort)40001);
+        def.DataType.ShouldBe(ModbusDataType.UInt16);
+    }
+
+    [Fact]
+    public void Rejects_a_non_address_blob()
+        => ModbusEquipmentTagParser.TryParse("""{"FullName":"x"}""", out _).ShouldBeFalse();
+
+    [Fact]
+    public void Rejects_garbage()
+        => ModbusEquipmentTagParser.TryParse("not json", out _).ShouldBeFalse();
+
+    [Fact]
+    public void Rejects_address_as_a_json_string()
+        => ModbusEquipmentTagParser.TryParse(
+            """{"region":"HoldingRegisters","address":"40001","dataType":"UInt16"}""", out _).ShouldBeFalse();
+
+    [Fact]
+    public void Rejects_address_out_of_ushort_range()
+        => ModbusEquipmentTagParser.TryParse(
+            """{"region":"HoldingRegisters","address":70000,"dataType":"UInt16"}""", out _).ShouldBeFalse();
+
+    /// <summary>
+    ///     End-to-end driver-level proof: a Modbus driver with NO authored tags can still read an
+    ///     equipment-tag ref (the raw TagConfig JSON) — the resolver parses it into a transient
+    ///     definition and the read goes to the wire instead of returning BadNodeIdUnknown.
+    /// </summary>
+    [Fact]
+    public async Task Driver_resolves_an_equipment_ref_and_reads_instead_of_BadNodeIdUnknown()
+    {
+        // Address 10 fits the fake transport's 256-register bank (40001 would overflow it).
+        var json = """{"region":"HoldingRegisters","address":10,"dataType":"UInt16","byteOrder":"BigEndian","bitIndex":0,"stringLength":0}""";
+        var fake = new ModbusDriverTests.FakeTransport();
+        var opts = new ModbusDriverOptions { Host = "fake", Tags = [] };
+        var drv = new ModbusDriver(opts, "modbus-eq", _ => fake);
+        await drv.InitializeAsync("{}", CancellationToken.None);
+        fake.HoldingRegisters[10] = 4242;
+
+        var r = await drv.ReadAsync([json], CancellationToken.None);
+
+        r[0].StatusCode.ShouldBe(0u);
+        r[0].StatusCode.ShouldNotBe(0x80340000u); // not BadNodeIdUnknown
+        r[0].Value.ShouldBe((ushort)4242);
+    }
+}