Files
lmxopcua/src/ZB.MOM.WW.OtOpcUa.Driver.S7/S7Driver.cs
Joseph Doherty 394d126b2e Phase 3 PR 64 -- S7 IReadable + IWritable via S7.Net string-based Plc.ReadAsync/WriteAsync. Adds IReadable + IWritable capability interfaces to S7Driver, routing reads/writes through S7netplus's string-address API (Plc.ReadAsync(string, ct) / Plc.WriteAsync(string, object, ct)). All operations serialize on the class's SemaphoreSlim Gate because S7netplus mandates one Plc connection per PLC with client-side serialization -- parallel reads against a single S7 CPU queue wire-side anyway and just eat connection-resource budget. Supported data types in this PR: Bool, Byte, Int16, UInt16, Int32, UInt32, Float32. S7.Net's string-based read returns UNSIGNED boxed values (DBX=bool, DBB=byte, DBW=ushort, DBD=uint); the driver reinterprets them into the requested S7DataType via the (DataType, Size, raw) switch: unchecked short-cast for Int16, unchecked int-cast for Int32, BitConverter.UInt32BitsToSingle for Float32. Writes inverse the conversion -- Int16 -> unchecked ushort cast, Int32 -> unchecked uint cast, Float32 -> BitConverter.SingleToUInt32Bits -- before handing to S7.Net's WriteAsync. This avoids a second PLC round-trip that a typed ReadAsync(DataType, db, offset, VarType, ...) overload would need. Int64, UInt64, Float64, String, DateTime throw NotSupportedException (-> BadNotSupported StatusCode); S7 STRING has non-trivial header semantics + LReal/DateTime need typed S7.Net API paths, both land in a follow-up PR when scope demands. InitializeAsync now parses every tag's Address string via S7AddressParser at init time. Bad addresses throw FormatException and flip health to Faulted -- callers can't register a broken driver. The parsed form goes into _parsedByName so Read/Write can consult Size/BitOffset without re-parsing per operation. StatusCode mapping in catch chain: unknown tag name -> BadNodeIdUnknown (0x80340000), unsupported data type -> BadNotSupported (0x803D0000), read-only tag write attempt -> BadNotWritable (0x803B0000), S7.Net PlcException (carries PUT/GET-disabled signal on S7-1200/1500) -> BadDeviceFailure (0x80550000) so operators see a TIA-Portal config problem rather than a transient-fault false flag per driver-specs.md \u00A75, any other runtime exception on read -> BadCommunicationError (0x80050000) to distinguish socket/timeout from tag-level faults. Write generic-exception path stays BadInternalError because write failures can legitimately be driver-side value-range problems. Unit tests (S7DriverReadWriteTests, 3 facts): Initialize_rejects_invalid_tag_address_and_fails_fast -- Tags with a malformed address must throw at InitializeAsync rather than producing a half-healthy driver; ReadAsync_without_initialize_throws_InvalidOperationException + WriteAsync_without_initialize_throws_InvalidOperationException -- pre-init calls hit RequirePlc and throw the uniform 'not initialized' message. Wire-level round-trip coverage (integration test against a live S7-1500 or a mock S7 server) is deferred -- S7.Net doesn't ship an in-process fake and a conformant mock is non-trivial. 53/53 Modbus.Driver.S7.Tests pass (50 parser + 3 read/write). dotnet build clean.
2026-04-19 00:10:41 -04:00

308 lines
15 KiB
C#

using S7.Net;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
namespace ZB.MOM.WW.OtOpcUa.Driver.S7;
/// <summary>
/// Siemens S7 native driver — speaks S7comm over ISO-on-TCP (port 102) via the S7netplus
/// library. First implementation of <see cref="IDriver"/> for an in-process .NET Standard
/// PLC protocol that is NOT Modbus, validating that the v2 driver-capability interfaces
/// generalize beyond Modbus + Galaxy.
/// </summary>
/// <remarks>
/// <para>
/// PR 62 ships the scaffold: <see cref="IDriver"/> only (Initialize / Reinitialize /
/// Shutdown / GetHealth). <see cref="ITagDiscovery"/>, <see cref="IReadable"/>,
/// <see cref="IWritable"/>, <see cref="ISubscribable"/>, <see cref="IHostConnectivityProbe"/>
/// land in PRs 63-65 once the address parser (PR 63) is in place.
/// </para>
/// <para>
/// <b>Single-connection policy</b>: S7netplus documented pattern is one
/// <c>Plc</c> instance per PLC, serialized with a <see cref="SemaphoreSlim"/>.
/// Parallelising reads against a single S7 CPU doesn't help — the CPU scans the
/// communication mailbox at most once per cycle (2-10 ms) and queues concurrent
/// requests wire-side anyway. Multiple client-side connections just waste the CPU's
/// 8-64 connection-resource budget.
/// </para>
/// </remarks>
public sealed class S7Driver(S7DriverOptions options, string driverInstanceId)
: IDriver, IReadable, IWritable, IDisposable, IAsyncDisposable
{
/// <summary>OPC UA StatusCode used when the tag name isn't in the driver's tag map.</summary>
private const uint StatusBadNodeIdUnknown = 0x80340000u;
/// <summary>OPC UA StatusCode used when the tag's data type isn't implemented yet.</summary>
private const uint StatusBadNotSupported = 0x803D0000u;
/// <summary>OPC UA StatusCode used when the tag is declared read-only.</summary>
private const uint StatusBadNotWritable = 0x803B0000u;
/// <summary>OPC UA StatusCode used when write fails validation (e.g. out-of-range value).</summary>
private const uint StatusBadInternalError = 0x80020000u;
/// <summary>OPC UA StatusCode used for socket / timeout / protocol-layer faults.</summary>
private const uint StatusBadCommunicationError = 0x80050000u;
/// <summary>OPC UA StatusCode used when S7 returns <c>ErrorCode.WrongCPU</c> / PUT/GET disabled.</summary>
private const uint StatusBadDeviceFailure = 0x80550000u;
private readonly Dictionary<string, S7TagDefinition> _tagsByName = new(StringComparer.OrdinalIgnoreCase);
private readonly Dictionary<string, S7ParsedAddress> _parsedByName = new(StringComparer.OrdinalIgnoreCase);
private readonly S7DriverOptions _options = options;
private readonly SemaphoreSlim _gate = new(1, 1);
/// <summary>
/// Per-connection gate. Internal so PRs 63-65 (read/write/subscribe) can serialize on
/// the same semaphore without exposing it publicly. Single-connection-per-PLC is a
/// hard requirement of S7netplus — see class remarks.
/// </summary>
internal SemaphoreSlim Gate => _gate;
/// <summary>
/// Active S7.Net PLC connection. Null until <see cref="InitializeAsync"/> returns; null
/// after <see cref="ShutdownAsync"/>. Read-only outside this class; PR 64's Read/Write
/// will take the <see cref="_gate"/> before touching it.
/// </summary>
internal Plc? Plc { get; private set; }
private DriverHealth _health = new(DriverState.Unknown, null, null);
private bool _disposed;
public string DriverInstanceId => driverInstanceId;
public string DriverType => "S7";
public async Task InitializeAsync(string driverConfigJson, CancellationToken cancellationToken)
{
_health = new DriverHealth(DriverState.Initializing, null, null);
try
{
var plc = new Plc(_options.CpuType, _options.Host, _options.Rack, _options.Slot);
// S7netplus writes timeouts into the underlying TcpClient via Plc.WriteTimeout /
// Plc.ReadTimeout (milliseconds). Set before OpenAsync so the handshake itself
// honours the bound.
plc.WriteTimeout = (int)_options.Timeout.TotalMilliseconds;
plc.ReadTimeout = (int)_options.Timeout.TotalMilliseconds;
using var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
cts.CancelAfter(_options.Timeout);
await plc.OpenAsync(cts.Token).ConfigureAwait(false);
Plc = plc;
// Parse every tag's address once at init so config typos fail fast here instead
// of surfacing as BadInternalError on every Read against the bad tag. The parser
// also rejects bit-offset > 7, DB 0, unknown area letters, etc.
_tagsByName.Clear();
_parsedByName.Clear();
foreach (var t in _options.Tags)
{
var parsed = S7AddressParser.Parse(t.Address); // throws FormatException
_tagsByName[t.Name] = t;
_parsedByName[t.Name] = parsed;
}
_health = new DriverHealth(DriverState.Healthy, DateTime.UtcNow, null);
}
catch (Exception ex)
{
// Clean up a partially-constructed Plc so a retry from the caller doesn't leak
// the TcpClient. S7netplus's Close() is best-effort and idempotent.
try { Plc?.Close(); } catch { }
Plc = null;
_health = new DriverHealth(DriverState.Faulted, null, ex.Message);
throw;
}
}
public async Task ReinitializeAsync(string driverConfigJson, CancellationToken cancellationToken)
{
await ShutdownAsync(cancellationToken).ConfigureAwait(false);
await InitializeAsync(driverConfigJson, cancellationToken).ConfigureAwait(false);
}
public Task ShutdownAsync(CancellationToken cancellationToken)
{
try { Plc?.Close(); } catch { /* best-effort — tearing down anyway */ }
Plc = null;
_health = new DriverHealth(DriverState.Unknown, _health.LastSuccessfulRead, null);
return Task.CompletedTask;
}
public DriverHealth GetHealth() => _health;
/// <summary>
/// Approximate memory footprint. The Plc instance + one 240-960 byte PDU buffer is
/// under 4 KB; return 0 because the <see cref="IDriver"/> contract asks for a
/// driver-attributable growth number and S7.Net doesn't expose one.
/// </summary>
public long GetMemoryFootprint() => 0;
public Task FlushOptionalCachesAsync(CancellationToken cancellationToken) => Task.CompletedTask;
// ---- IReadable ----
public async Task<IReadOnlyList<DataValueSnapshot>> ReadAsync(
IReadOnlyList<string> fullReferences, CancellationToken cancellationToken)
{
var plc = RequirePlc();
var now = DateTime.UtcNow;
var results = new DataValueSnapshot[fullReferences.Count];
await _gate.WaitAsync(cancellationToken).ConfigureAwait(false);
try
{
for (var i = 0; i < fullReferences.Count; i++)
{
var name = fullReferences[i];
if (!_tagsByName.TryGetValue(name, out var tag))
{
results[i] = new DataValueSnapshot(null, StatusBadNodeIdUnknown, null, now);
continue;
}
try
{
var value = await ReadOneAsync(plc, tag, cancellationToken).ConfigureAwait(false);
results[i] = new DataValueSnapshot(value, 0u, now, now);
_health = new DriverHealth(DriverState.Healthy, now, null);
}
catch (NotSupportedException)
{
results[i] = new DataValueSnapshot(null, StatusBadNotSupported, null, now);
}
catch (global::S7.Net.PlcException pex)
{
// S7.Net's PlcException carries an ErrorCode; PUT/GET-disabled on
// S7-1200/1500 surfaces here. Map to BadDeviceFailure so operators see a
// device-config problem (toggle PUT/GET in TIA Portal) rather than a
// transient fault — per driver-specs.md §5.
results[i] = new DataValueSnapshot(null, StatusBadDeviceFailure, null, now);
_health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, pex.Message);
}
catch (Exception ex)
{
results[i] = new DataValueSnapshot(null, StatusBadCommunicationError, null, now);
_health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, ex.Message);
}
}
}
finally { _gate.Release(); }
return results;
}
private async Task<object> ReadOneAsync(global::S7.Net.Plc plc, S7TagDefinition tag, CancellationToken ct)
{
var addr = _parsedByName[tag.Name];
// S7.Net's string-based ReadAsync returns object where the boxed .NET type depends on
// the size suffix: DBX=bool, DBB=byte, DBW=ushort, DBD=uint. Our S7DataType enum
// specifies the SEMANTIC type (Int16 vs UInt16 vs Float32 etc.); the reinterpret below
// converts the raw unsigned boxed value into the requested type without issuing an
// extra PLC round-trip.
var raw = await plc.ReadAsync(tag.Address, ct).ConfigureAwait(false)
?? throw new System.IO.InvalidDataException($"S7.Net returned null for '{tag.Address}'");
return (tag.DataType, addr.Size, raw) switch
{
(S7DataType.Bool, S7Size.Bit, bool b) => b,
(S7DataType.Byte, S7Size.Byte, byte by) => by,
(S7DataType.UInt16, S7Size.Word, ushort u16) => u16,
(S7DataType.Int16, S7Size.Word, ushort u16) => unchecked((short)u16),
(S7DataType.UInt32, S7Size.DWord, uint u32) => u32,
(S7DataType.Int32, S7Size.DWord, uint u32) => unchecked((int)u32),
(S7DataType.Float32, S7Size.DWord, uint u32) => BitConverter.UInt32BitsToSingle(u32),
(S7DataType.Int64, _, _) => throw new NotSupportedException("S7 Int64 reads land in a follow-up PR"),
(S7DataType.UInt64, _, _) => throw new NotSupportedException("S7 UInt64 reads land in a follow-up PR"),
(S7DataType.Float64, _, _) => throw new NotSupportedException("S7 Float64 (LReal) reads land in a follow-up PR"),
(S7DataType.String, _, _) => throw new NotSupportedException("S7 STRING reads land in a follow-up PR"),
(S7DataType.DateTime, _, _) => throw new NotSupportedException("S7 DateTime reads land in a follow-up PR"),
_ => throw new System.IO.InvalidDataException(
$"S7 Read type-mismatch: tag '{tag.Name}' declared {tag.DataType} but address '{tag.Address}' " +
$"parsed as Size={addr.Size}; S7.Net returned {raw.GetType().Name}"),
};
}
// ---- IWritable ----
public async Task<IReadOnlyList<WriteResult>> WriteAsync(
IReadOnlyList<WriteRequest> writes, CancellationToken cancellationToken)
{
var plc = RequirePlc();
var results = new WriteResult[writes.Count];
await _gate.WaitAsync(cancellationToken).ConfigureAwait(false);
try
{
for (var i = 0; i < writes.Count; i++)
{
var w = writes[i];
if (!_tagsByName.TryGetValue(w.FullReference, out var tag))
{
results[i] = new WriteResult(StatusBadNodeIdUnknown);
continue;
}
if (!tag.Writable)
{
results[i] = new WriteResult(StatusBadNotWritable);
continue;
}
try
{
await WriteOneAsync(plc, tag, w.Value, cancellationToken).ConfigureAwait(false);
results[i] = new WriteResult(0u);
}
catch (NotSupportedException)
{
results[i] = new WriteResult(StatusBadNotSupported);
}
catch (global::S7.Net.PlcException)
{
results[i] = new WriteResult(StatusBadDeviceFailure);
}
catch (Exception)
{
results[i] = new WriteResult(StatusBadInternalError);
}
}
}
finally { _gate.Release(); }
return results;
}
private async Task WriteOneAsync(global::S7.Net.Plc plc, S7TagDefinition tag, object? value, CancellationToken ct)
{
// S7.Net's Plc.WriteAsync(string address, object value) expects the boxed value to
// match the address's size-suffix type: DBX=bool, DBB=byte, DBW=ushort, DBD=uint.
// Our S7DataType lets the caller pass short/int/float; convert to the unsigned
// wire representation before handing off.
var boxed = tag.DataType switch
{
S7DataType.Bool => (object)Convert.ToBoolean(value),
S7DataType.Byte => (object)Convert.ToByte(value),
S7DataType.UInt16 => (object)Convert.ToUInt16(value),
S7DataType.Int16 => (object)unchecked((ushort)Convert.ToInt16(value)),
S7DataType.UInt32 => (object)Convert.ToUInt32(value),
S7DataType.Int32 => (object)unchecked((uint)Convert.ToInt32(value)),
S7DataType.Float32 => (object)BitConverter.SingleToUInt32Bits(Convert.ToSingle(value)),
S7DataType.Int64 => throw new NotSupportedException("S7 Int64 writes land in a follow-up PR"),
S7DataType.UInt64 => throw new NotSupportedException("S7 UInt64 writes land in a follow-up PR"),
S7DataType.Float64 => throw new NotSupportedException("S7 Float64 (LReal) writes land in a follow-up PR"),
S7DataType.String => throw new NotSupportedException("S7 STRING writes land in a follow-up PR"),
S7DataType.DateTime => throw new NotSupportedException("S7 DateTime writes land in a follow-up PR"),
_ => throw new InvalidOperationException($"Unknown S7DataType {tag.DataType}"),
};
await plc.WriteAsync(tag.Address, boxed, ct).ConfigureAwait(false);
}
private global::S7.Net.Plc RequirePlc() =>
Plc ?? throw new InvalidOperationException("S7Driver not initialized");
public void Dispose() => DisposeAsync().AsTask().GetAwaiter().GetResult();
public async ValueTask DisposeAsync()
{
if (_disposed) return;
_disposed = true;
try { await ShutdownAsync(CancellationToken.None).ConfigureAwait(false); }
catch { /* disposal is best-effort */ }
_gate.Dispose();
}
}