diff --git a/code-reviews/Driver.S7/findings.md b/code-reviews/Driver.S7/findings.md
index c10bcb88..ed9d00d7 100644
--- a/code-reviews/Driver.S7/findings.md
+++ b/code-reviews/Driver.S7/findings.md
@@ -495,3 +495,5 @@ open-ended deferral.
**Recommendation:** Add `int? ArrayCount` and `bool? IsArray` to `S7TagDto` and propagate them through `BuildTag`. Mirror the `S7EquipmentTagParser` semantics (honour `arrayLength` only when `isArray` is true and the value is positive).
**Resolution:** Deferred — requires an AdminUI page/DTO change and a corresponding config-form field addition. Tracked as a follow-up to the array-read Phase 4d work. No code change in this review; the existing init guard-(e) correctly rejects any programmatically-constructed writable array reaching the driver until the DTO is wired.
+
+**Update (2026-10-08, #610 item 2):** the DTO half was already stale — `S7TagDto` is gone and `S7TagDefinitionFactory` reads `isArray`/`arrayLength` from TagConfig. Remaining pieces now done: the driver write path (`EncodeArrayBlock` + one contiguous `WriteBytesAsync`; guard-(e) narrowed to writable **Bool** arrays, which would clobber neighbouring bits), and AdminUI author-time validation in `S7TagConfigModel` (the isArray/arrayLength controls live in the TagModal's generic `TagArrayConfig`, not the S7 editor). Server-side exposure of array writes stays with #610 item 1.
diff --git a/docs/Uns.md b/docs/Uns.md
index b900f3d9..c053afab 100644
--- a/docs/Uns.md
+++ b/docs/Uns.md
@@ -314,7 +314,7 @@ Combined with historization (values are arrays — history of the whole array sn
### Out of scope (named deferrals)
-- **Array writes** (inbound client→device write of an array value) — tagged for a follow-up phase.
+- **Array writes** (inbound client→device write of an array value) — tagged for a follow-up phase. The S7 driver's array write path exists (`Byte`/`Int16`/`UInt16`/`Int32`/`UInt32`/`Float32`, not `Bool`; see [S7.md](drivers/S7.md)) but the applier still forces array nodes read-only (#610 item 1).
- **Multi-dimensional arrays** (`ValueRank > 1`) — not supported; all arrays are 1-D.
- **Array historization** — a historized array tag materialises with the correct `Historizing` flag, but the historian backend treats the value as an opaque blob; per-element history is out of scope. (Continuous historization is numeric-analog only — array / non-numeric values are not recorded.)
diff --git a/docs/drivers/S7.md b/docs/drivers/S7.md
index 492f2faa..fea36579 100644
--- a/docs/drivers/S7.md
+++ b/docs/drivers/S7.md
@@ -195,6 +195,21 @@ Portal under *Protection & Security* for the CPU.
| PUT/GET denied | `BadNotSupported` | `Faulted` (config alert) |
| CPU / hardware fault | `BadDeviceFailure` | `Degraded` |
| Socket / timeout | `BadCommunicationError` | `Degraded` |
+| Reconnect suppressed (backoff window) | `BadCommunicationError` | `Degraded` |
+| Array write of the wrong shape / length / element type | `BadTypeMismatch` | unchanged |
+| Bool / wide-type array write | `BadNotSupported` | unchanged |
+
+**Health is decided once per pass, worst state wins.** A read pass and a write batch each
+accumulate their outcomes and write health once (`Healthy < Degraded < Faulted`), so a PUT/GET-denied
+`Faulted` item is not erased by a later `Degraded` or successful sibling. The write-side `Faulted` is
+**sticky against reads**: a clean read pass (reads often work against a write-protected CPU) leaves
+`Faulted` in place and only advances `LastSuccessfulRead`; the next write that succeeds clears it. A
+transient `Degraded` write failure is still cleared by a clean read, as before.
+
+**Connect backoff.** A dead PLC costs one connect attempt per backoff window (1 s doubling to a 30 s
+cap), not one per read / poll tick / probe tick: inside the window `EnsureConnectedAsync` fails fast
+(`BadCommunicationError`, `Degraded`) without a connect. A successful connect clears the window, so a
+fresh drop after a healthy period reconnects immediately; worst-case recovery lag is the 30 s cap.
## Testing
@@ -228,7 +243,18 @@ normal dev (the S7 sim is on the shared Docker host but currently offline).
**Live-verify** — integration-fixture-gated (not Mac-verifiable without the S7 sim up).
-**Deferrals** — array *writes*, multi-dimensional arrays, per-element historization,
+**Array writes (S7-016)** — a writable `Byte` / `Int16` / `UInt16` / `Int32` / `UInt32` / `Float32` array
+is written as ONE contiguous `WriteBytesAsync` of `count x element-bytes` (the inverse of the read
+decode), and the value must be an array of exactly `arrayLength` elements (else `BadTypeMismatch`, no
+health impact). **Writable `Bool` arrays are refused at init** (`NotSupportedException`): the array
+read is byte-granular, so a matching write would overwrite the 7 neighbouring bits of every byte it
+touches, and a safe bit-packed write needs read-modify-write. Mark Bool arrays `writable: false`.
+Note the *server* still presents every array node read-only to OPC UA clients ([Uns.md §Array
+tags](../Uns.md#array-tags-1-d), #610 item 1) — the driver path is reachable today through the Client
+CLI / driver-level callers and is proven by the unit suite plus the snap7 fixture test
+(`S7_1500ArrayWriteTests`); the AdminUI tag editor rejects wide-type and writable-Bool arrays at author time.
+
+**Deferrals** — server-side exposure of array writes, multi-dimensional arrays, per-element historization,
wide-type array elements (`Int64`, `UInt64`, `Float64`, `String`, `DateTime`), and
Timer/Counter array elements.
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7Driver.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7Driver.cs
index bed5e1bc..8aa78144 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7Driver.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7Driver.cs
@@ -115,6 +115,8 @@ public sealed class S7Driver
private const uint StatusBadNodeIdUnknown = 0x80340000u;
/// OPC UA StatusCode used when the tag's data type isn't implemented yet.
private const uint StatusBadNotSupported = 0x803D0000u;
+ /// OPC UA StatusCode used when a written value has the wrong shape / length / element type.
+ private const uint StatusBadTypeMismatch = 0x80740000u;
/// OPC UA StatusCode used when the tag is declared read-only.
private const uint StatusBadNotWritable = 0x803B0000u;
/// OPC UA StatusCode used when write fails validation (e.g. out-of-range value).
@@ -179,6 +181,38 @@ public sealed class S7Driver
private bool _plcDead;
private DriverHealth _health = new(DriverState.Unknown, null, null);
+
+ ///
+ /// The health snapshot, accessed with volatile semantics: it is written from the gate-holding
+ /// read/write passes, the poll engine's error sink and the lifecycle methods, and read lock-free
+ /// by (the health tick) — the same Volatile idiom ModbusDriver uses.
+ /// is an immutable record, so a reference swap is a complete update.
+ ///
+ private DriverHealth Health
+ {
+ get => Volatile.Read(ref _health);
+ set => Volatile.Write(ref _health, value);
+ }
+
+ ///
+ /// Per-device connect-attempt throttle (STAB-21): a dead PLC costs one connect attempt per
+ /// backoff window (1 s doubling to 30 s) instead of one per data call / poll tick / probe tick.
+ /// Not internally synchronized — only touched from (under
+ /// ) and from init/shutdown, which run with every loop drained.
+ ///
+ private readonly ConnectionBackoff _connectBackoff =
+ new(TimeSpan.FromSeconds(1), TimeSpan.FromSeconds(30));
+
+ /// Clock the connect backoff is measured on. Internal so tests step it deterministically.
+ internal Func BackoffClock { get; set; } = static () => DateTime.UtcNow;
+
+ ///
+ /// The sticky write-side config fault (access denied / PUT-GET disabled), or null. A read
+ /// pass that finds everything readable must NOT erase it (reads can succeed while writes are
+ /// protected); it is cleared by the next write pass that writes something successfully.
+ /// Guarded by .
+ ///
+ private (DriverState State, string Message)? _writeFault;
private bool _disposed;
///
@@ -189,7 +223,7 @@ public sealed class S7Driver
///
public async Task InitializeAsync(string driverConfigJson, CancellationToken cancellationToken)
{
- _health = new DriverHealth(DriverState.Initializing, null, null);
+ Health = new DriverHealth(DriverState.Initializing, null, null);
try
{
// Re-parse the supplied DriverConfig JSON so a config change delivered through the
@@ -263,6 +297,7 @@ public sealed class S7Driver
Plc = plc;
_plcDead = false;
+ _connectBackoff.RecordSuccess();
// 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
@@ -274,7 +309,7 @@ public sealed class S7Driver
}
_initialized = true;
- _health = new DriverHealth(DriverState.Healthy, DateTime.UtcNow, null);
+ Health = new DriverHealth(DriverState.Healthy, DateTime.UtcNow, null);
_logger.LogInformation("S7Driver connected. Driver={DriverInstanceId} Host={Host} CPU={CpuType} Tags={TagCount}",
_driverInstanceId, _options.Host, _options.CpuType, _tagsByRawPath.Count);
@@ -299,7 +334,7 @@ public sealed class S7Driver
Plc = null;
_initialized = false;
_plcDead = false;
- _health = new DriverHealth(DriverState.Faulted, null, ex.Message);
+ Health = new DriverHealth(DriverState.Faulted, null, ex.Message);
_logger.LogError(ex, "S7Driver connect failed. Driver={DriverInstanceId} Host={Host}", _driverInstanceId, _options.Host);
throw;
}
@@ -346,13 +381,15 @@ public sealed class S7Driver
_initialized = false;
_plcDead = false;
+ _writeFault = null;
+ _connectBackoff.RecordSuccess();
try { Plc?.Dispose(); } catch { /* best-effort — tearing down anyway */ }
Plc = null;
- _health = new DriverHealth(DriverState.Unknown, _health.LastSuccessfulRead, null);
+ Health = new DriverHealth(DriverState.Unknown, Health.LastSuccessfulRead, null);
}
///
- public DriverHealth GetHealth() => _health;
+ public DriverHealth GetHealth() => Health;
///
/// True when carries a real config body. The
@@ -453,19 +490,18 @@ public sealed class S7Driver
"Timer/Counter are read-only this phase; set Writable=false.");
}
- // (e) Array tag declared Writable — WriteOneAsync has no WriteArrayAsync path yet.
- // Without this guard a writable array node is discovered and
- // accepted, then every write returns BadCommunicationError (InvalidCastException from
- // BoxValueForWrite receiving a typed array) instead of the informative BadNotSupported
- // the caller could act on. Wide-type arrays are already rejected above (guard-a); this
- // targets non-wide types (Int16[], Byte[], Float32[], etc.) that ARE supported for
- // reading but not yet for writing.
- if (t.ArrayCount is >= 1 && t.Writable)
+ // (e) Bool array declared Writable — element writes are byte-granular (one byte per
+ // element, mirroring the read), so a write would overwrite the 7 neighbouring bits of
+ // every byte it touches; a safe bit-packed write needs read-modify-write and is not
+ // implemented. Every other supported element type (Byte/Int16/UInt16/Int32/UInt32/
+ // Float32) writes as ONE contiguous block (EncodeArrayBlock) — S7-016. Wide-type arrays
+ // are already rejected above (guard-a).
+ if (t.ArrayCount is >= 1 && t.Writable && t.DataType == S7DataType.Bool)
{
throw new NotSupportedException(
- $"S7 tag '{t.Name}' is a {t.DataType} array (ArrayCount={t.ArrayCount}) declared Writable — " +
- "array writes are not yet supported by the S7 driver. Set Writable=false for read-only array tags, " +
- "or split into individual scalar tags until array-write support lands.");
+ $"S7 tag '{t.Name}' is a Bool array (ArrayCount={t.ArrayCount}) declared Writable — " +
+ "Bool array writes are not supported (a byte-granular write would clobber the neighbouring " +
+ "bits). Set Writable=false, or write the bits as individual scalar Bool tags.");
}
}
}
@@ -567,7 +603,7 @@ public sealed class S7Driver
{
for (var i = 0; i < fullReferences.Count; i++)
results[i] = new DataValueSnapshot(null, StatusBadCommunicationError, null, now);
- _health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, ex.Message);
+ Health = new DriverHealth(DriverState.Degraded, Health.LastSuccessfulRead, ex.Message);
return results;
}
@@ -683,12 +719,23 @@ public sealed class S7Driver
//
// LastSuccessfulRead advances whenever ANYTHING read, even into a Degraded/Faulted
// state — see ReadPassOutcome for why that is load-bearing.
+ //
+ // A sticky write-side Faulted (PUT/GET denied) outranks a read pass that found less
+ // wrong: reads can succeed against a CPU whose writes are protected, and a clean read
+ // must not erase the config alert. The write pass clears it on its next success.
if (outcome.HasObservations)
{
- _health = new DriverHealth(
- outcome.WorstFailure,
- outcome.AnySuccess ? now : _health.LastSuccessfulRead,
- outcome.WorstFailure == DriverState.Healthy ? null : outcome.WorstError);
+ var state = outcome.WorstFailure;
+ var error = state == DriverState.Healthy ? null : outcome.WorstError;
+ if (_writeFault is { } wf && ReadPassOutcome.Rank(wf.State) > ReadPassOutcome.Rank(state))
+ {
+ state = wf.State;
+ error = wf.Message;
+ }
+ Health = new DriverHealth(
+ state,
+ outcome.AnySuccess ? now : Health.LastSuccessfulRead,
+ error);
}
_gate.Release();
@@ -698,7 +745,7 @@ public sealed class S7Driver
///
/// The outcomes ONE pass observed, accumulated so the pass writes
- /// exactly once — worst state wins.
+ /// exactly once — worst state wins.
///
///
///
@@ -780,7 +827,7 @@ public sealed class S7Driver
/// Severity order the pass ranks by: Healthy (none) < Degraded < Faulted.
/// The state to rank.
/// Its severity, higher being worse.
- private static int Rank(DriverState state) => state switch
+ internal static int Rank(DriverState state) => state switch
{
DriverState.Faulted => 2,
DriverState.Degraded => 1,
@@ -1129,7 +1176,7 @@ public sealed class S7Driver
///
///
/// The health state is recorded, not applied. It goes into
- /// so the pass can write once at the
+ /// so the pass can write once at the
/// end, worst-state-wins — writing it here is what let a later good tag erase this
/// failure. The _plcDead / side effects
/// stay IMMEDIATE: they govern whether the very next read reopens the handle, which
@@ -1691,6 +1738,8 @@ public sealed class S7Driver
ArgumentNullException.ThrowIfNull(writes);
RequireInitialized();
var results = new WriteResult[writes.Count];
+ // Health is decided ONCE, at the end of the batch, worst-state-wins — see WritePassOutcome.
+ var outcome = new WritePassOutcome();
await _gate.WaitAsync(cancellationToken).ConfigureAwait(false);
try
@@ -1709,7 +1758,7 @@ public sealed class S7Driver
{
for (var i = 0; i < writes.Count; i++)
results[i] = new WriteResult(StatusBadCommunicationError);
- _health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, ex.Message);
+ outcome.RecordFailure(DriverState.Degraded, ex.Message);
return results;
}
@@ -1746,6 +1795,7 @@ public sealed class S7Driver
{
await WriteOneAsync(plc, tag, w.Value, cancellationToken).ConfigureAwait(false);
results[i] = new WriteResult(0u);
+ outcome.RecordSuccess();
}
catch (OperationCanceledException)
{
@@ -1761,13 +1811,18 @@ public sealed class S7Driver
{
results[i] = new WriteResult(StatusBadNotSupported);
}
+ catch (S7WriteValueException)
+ {
+ // Client-supplied value of the wrong shape — not a device or comms fault.
+ results[i] = new WriteResult(StatusBadTypeMismatch);
+ }
catch (PlcException pex) when (IsAccessDenied(pex))
{
// PUT/GET-disabled / access-protection on write — same permanent
// configuration fault as on read. BadNotSupported +
// a config-alert health state, not a transient device failure.
results[i] = new WriteResult(StatusBadNotSupported);
- _health = new DriverHealth(DriverState.Faulted, _health.LastSuccessfulRead,
+ outcome.RecordFailure(DriverState.Faulted,
"S7 access denied — enable PUT/GET communication in TIA Portal " +
$"(Protection & Security) for this CPU. PLC reported: {pex.Message}");
}
@@ -1779,7 +1834,7 @@ public sealed class S7Driver
// dead so the next call reopens.
MarkConnectionDeadIfFatal(pex);
results[i] = new WriteResult(StatusBadDeviceFailure);
- _health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, pex.Message);
+ outcome.RecordFailure(DriverState.Degraded, pex.Message);
}
catch (Exception ex)
{
@@ -1788,25 +1843,84 @@ public sealed class S7Driver
// dead when it's a connection loss.
MarkConnectionDeadIfFatal(ex);
results[i] = new WriteResult(StatusBadCommunicationError);
- _health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, ex.Message);
+ outcome.RecordFailure(DriverState.Degraded, ex.Message);
}
}
}
- finally { _gate.Release(); }
+ finally
+ {
+ // THE single health write of the batch (a finally, so an OCE mid-batch still flushes the
+ // evidence gathered so far — a pass that observed nothing writes nothing).
+ ApplyWritePassHealth(outcome);
+ _gate.Release();
+ }
return results;
}
+ ///
+ /// Publishes one write batch's verdict (STAB-22): worst state wins over every outcome the
+ /// batch recorded, so a Faulted access-denied item is not erased by a later Degraded or
+ /// successful sibling. Maintains , the sticky Faulted a read pass
+ /// must not erase. Caller holds .
+ ///
+ /// The batch's accumulated outcomes.
+ private void ApplyWritePassHealth(WritePassOutcome outcome)
+ {
+ if (!outcome.HasObservations) return;
+
+ var worst = outcome.WorstFailure;
+ if (worst == DriverState.Faulted)
+ _writeFault = (DriverState.Faulted, outcome.WorstError!);
+ else if (outcome.AnySuccess)
+ _writeFault = null; // a write got through — the protection fault is gone
+
+ if (worst == DriverState.Healthy)
+ {
+ // Success-only batch: no health write, except to retire a Faulted that WE (the write
+ // side) were holding — a clean write is the only evidence the alert has cleared.
+ if (outcome.AnySuccess && _writeFault is null && Health.State == DriverState.Faulted)
+ Health = new DriverHealth(DriverState.Healthy, Health.LastSuccessfulRead, null);
+ return;
+ }
+
+ var state = worst;
+ var error = outcome.WorstError;
+ // A Degraded-only batch must not downgrade a still-sticky Faulted.
+ if (_writeFault is { } wf && ReadPassOutcome.Rank(wf.State) > ReadPassOutcome.Rank(state))
+ {
+ state = wf.State;
+ error = wf.Message;
+ }
+ Health = new DriverHealth(state, Health.LastSuccessfulRead, error);
+ }
+
+ ///
+ /// The outcomes ONE batch observed — the write-side sibling of
+ /// (same worst-state-wins ranking and severity-pinned message),
+ /// accumulated so the batch writes once instead of per item.
+ ///
+ private sealed class WritePassOutcome
+ {
+ private readonly ReadPassOutcome _inner = new();
+
+ /// True once any item in the batch wrote successfully.
+ public bool AnySuccess => _inner.AnySuccess;
+ /// The worst failure recorded; Healthy means none.
+ public DriverState WorstFailure => _inner.WorstFailure;
+ /// The message explaining .
+ public string? WorstError => _inner.WorstError;
+ /// True once the batch observed a success or a failure.
+ public bool HasObservations => _inner.HasObservations;
+ /// Records one successful write.
+ public void RecordSuccess() => _inner.RecordSuccess();
+ /// Records one failed write.
+ /// The state the failure would have stamped alone.
+ /// The operator-facing message.
+ public void RecordFailure(DriverState state, string message) => _inner.RecordFailure(state, message);
+ }
+
private async Task WriteOneAsync(IS7Plc plc, S7TagDefinition tag, object? value, CancellationToken ct)
{
- // Defence-in-depth guard: authored array tags are rejected at init
- // (RejectUnsupportedTagConfigs guard-e), but a transient equipment-tag ref resolved by
- // _resolver bypasses that path. Both should fail with NotSupportedException → BadNotSupported,
- // not InvalidCastException → BadCommunicationError from BoxValueForWrite receiving an array.
- if (tag.ArrayCount is >= 1)
- throw new NotSupportedException(
- $"S7 array writes are not yet supported (tag '{tag.Name}'). " +
- "Use individual scalar tags or set Writable=false for read-only arrays.");
-
// Parse the address the same way ReadOneAsync does: every tag pre-parses at init
// (_parsedByRawPath), with an on-demand parse as a defensive fallback. Needed here so the
// wide-type write can byte-address the block (the narrow path below addresses by the raw
@@ -1815,6 +1929,17 @@ public sealed class S7Driver
? parsed
: S7AddressParser.Parse(tag.Address);
+ // Array path (S7-016): ONE contiguous WriteBytesAsync of count × element-bytes — the inverse
+ // of ReadArrayAsync. Bool / wide-type arrays throw NotSupportedException (→ BadNotSupported);
+ // a wrong-shaped value throws S7WriteValueException (→ BadTypeMismatch, no health impact).
+ if (tag.ArrayCount is >= 1)
+ {
+ var arrayBytes = EncodeArrayBlock(tag, addr, value);
+ await plc.WriteBytesAsync(ToS7NetArea(addr.Area), addr.DbNumber, addr.ByteOffset, arrayBytes, ct)
+ .ConfigureAwait(false);
+ return;
+ }
+
// Wide/structured scalar path: encode the value to a big-endian byte block and write it
// at the start byte via S7.Net's buffer-based WriteBytesAsync. Mirrors the read seam;
// the narrow string-based write below stays unchanged for 1/2/4-byte types.
@@ -1832,6 +1957,90 @@ public sealed class S7Driver
await plc.WriteAsync(tag.Address, boxed, ct).ConfigureAwait(false);
}
+ ///
+ /// Pure encode loop — the inverse of : turns the caller's array
+ /// into the contiguous big-endian block for a single WriteBytesAsync. No network I/O.
+ /// Accepts any non-string (OPC UA hands the server
+ /// a typed array, but a boxed object[] is equally fine); each element is coerced with
+ /// Convert.To* like the scalar path.
+ ///
+ /// Tag definition carrying the element type and declared array length.
+ /// Parsed address carrying the access .
+ /// The array to encode; must hold exactly ArrayCount elements.
+ /// The big-endian block, count × element-bytes long.
+ /// Bool or wide-type element arrays.
+ /// The value is not an array, has the wrong length, or an
+ /// element does not convert to the element type.
+ internal static byte[] EncodeArrayBlock(S7TagDefinition tag, S7ParsedAddress addr, object? value)
+ {
+ var count = tag.ArrayCount!.Value;
+
+ switch (tag.DataType, addr.Size)
+ {
+ case (S7DataType.Bool, _):
+ throw new NotSupportedException(
+ $"S7 Bool array writes are not supported (tag '{tag.Name}'): a byte-granular write would clobber neighbouring bits.");
+ case (S7DataType.Int64, _):
+ case (S7DataType.UInt64, _):
+ case (S7DataType.Float64, _):
+ case (S7DataType.String, _):
+ case (S7DataType.DateTime, _):
+ throw new NotSupportedException($"S7 array writes of {tag.DataType} are not supported (tag '{tag.Name}').");
+ case (S7DataType.Byte, S7Size.Byte):
+ case (S7DataType.UInt16, S7Size.Word):
+ case (S7DataType.Int16, S7Size.Word):
+ case (S7DataType.UInt32, S7Size.DWord):
+ case (S7DataType.Int32, S7Size.DWord):
+ case (S7DataType.Float32, S7Size.DWord):
+ break;
+ default:
+ throw new System.IO.InvalidDataException(
+ $"S7 array Write type-mismatch: tag '{tag.Name}' declared {tag.DataType} but address " +
+ $"'{tag.Address}' parsed as Size={addr.Size}");
+ }
+
+ if (value is string || value is not System.Collections.IEnumerable items)
+ throw new S7WriteValueException($"S7 array tag '{tag.Name}' requires an array value.");
+
+ var elements = new List
/// Cancellation token for the (re)connect attempt.
@@ -1922,6 +2128,12 @@ public sealed class S7Driver
}
_plcDead = false;
+ // STAB-21: inside the backoff window fail fast WITHOUT a connect attempt. A plain
+ // InvalidOperationException (not an OCE) so the read/write/probe catch ladders degrade on it.
+ if (!_connectBackoff.ShouldAttempt(BackoffClock()))
+ throw new InvalidOperationException(
+ $"S7 reconnect to {_options.Host}:{_options.Port} suppressed — backing off after a failed connect attempt.");
+
var plc = _plcFactory.Create(
_options.CpuType, _options.Host, _options.Port, _options.Rack, _options.Slot, _options.Timeout);
try
@@ -1932,6 +2144,7 @@ public sealed class S7Driver
}
catch (OperationCanceledException) when (!ct.IsCancellationRequested)
{
+ _connectBackoff.RecordFailure(BackoffClock());
// The linked CancelAfter fired — a connect TIMEOUT, not a caller cancellation.
// Surface it as a connection FAILURE (TimeoutException) so callers route it through
// their degrade paths: an escaping OCE reads as teardown and permanently killed the
@@ -1941,12 +2154,16 @@ public sealed class S7Driver
$"S7 connect to {_options.Host}:{_options.Port} timed out after " +
$"{(int)_options.Timeout.TotalMilliseconds} ms.");
}
- catch
+ catch (Exception ex)
{
+ // Caller cancellation is teardown, not a dead PLC — it must not open a window.
+ if (!(ex is OperationCanceledException && ct.IsCancellationRequested))
+ _connectBackoff.RecordFailure(BackoffClock());
try { plc.Dispose(); } catch { /* best-effort */ }
throw;
}
+ _connectBackoff.RecordSuccess();
Plc = plc;
_logger.LogInformation("S7Driver reconnected. Driver={DriverInstanceId} Host={Host} CPU={CpuType}",
_driverInstanceId, _options.Host, _options.CpuType);
@@ -2114,8 +2331,8 @@ public sealed class S7Driver
private void HandlePollError(Exception ex)
{
_logger.LogWarning(ex, "S7 poll reader failed. Driver={DriverInstanceId}", _driverInstanceId);
- if (_health.State != DriverState.Faulted)
- _health = new DriverHealth(DriverState.Degraded, _health.LastSuccessfulRead, ex.Message);
+ if (Health.State != DriverState.Faulted)
+ Health = new DriverHealth(DriverState.Degraded, Health.LastSuccessfulRead, ex.Message);
}
// ---- IHostConnectivityProbe ----
@@ -2257,8 +2474,10 @@ public sealed class S7Driver
_initialized = false;
_plcDead = false;
+ _writeFault = null;
+ _connectBackoff.RecordSuccess();
try { Plc?.Dispose(); } catch { /* best-effort — tearing down anyway */ }
Plc = null;
- _health = new DriverHealth(DriverState.Unknown, _health.LastSuccessfulRead, null);
+ Health = new DriverHealth(DriverState.Unknown, Health.LastSuccessfulRead, null);
}
}
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7DriverFactoryExtensions.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7DriverFactoryExtensions.cs
index 36d754c0..8fa880aa 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7DriverFactoryExtensions.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7/S7DriverFactoryExtensions.cs
@@ -1,5 +1,6 @@
using System.Text.Json;
using System.Text.Json.Serialization;
+using Microsoft.Extensions.Logging;
using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
using ZB.MOM.WW.OtOpcUa.Core.Hosting;
@@ -16,22 +17,32 @@ public static class S7DriverFactoryExtensions
public const string DriverTypeName = "S7";
/// Registers the S7 driver factory with the registry.
+ ///
+ /// The optional is captured at registration time and used to
+ /// build an per driver instance — without it the driver runs on
+ /// the null logger and none of its diagnostics (connect/reconnect, skipped tags, poll faults)
+ /// reach the node log (CONV-3).
+ ///
/// The driver factory registry.
- public static void Register(DriverFactoryRegistry registry)
+ /// Optional logger factory for driver instances.
+ public static void Register(DriverFactoryRegistry registry, ILoggerFactory? loggerFactory = null)
{
ArgumentNullException.ThrowIfNull(registry);
- registry.Register(DriverTypeName, CreateInstance);
+ registry.Register(DriverTypeName, (id, json) => CreateInstance(id, json, loggerFactory));
}
/// Creates a new S7 driver instance from configuration.
/// The unique identifier for the driver instance.
/// The JSON configuration for the driver.
/// A newly created S7 driver instance.
- internal static S7Driver CreateInstance(string driverInstanceId, string driverConfigJson)
+ /// Optional logger factory for the driver instance.
+ internal static S7Driver CreateInstance(
+ string driverInstanceId, string driverConfigJson, ILoggerFactory? loggerFactory = null)
{
ArgumentException.ThrowIfNullOrWhiteSpace(driverInstanceId);
ArgumentException.ThrowIfNullOrWhiteSpace(driverConfigJson);
- return new S7Driver(ParseOptions(driverInstanceId, driverConfigJson), driverInstanceId);
+ return new S7Driver(ParseOptions(driverInstanceId, driverConfigJson), driverInstanceId,
+ logger: loggerFactory?.CreateLogger());
}
///
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/S7TagConfigModel.cs b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/S7TagConfigModel.cs
index 1692f39a..3e944d4a 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/S7TagConfigModel.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/S7TagConfigModel.cs
@@ -112,6 +112,26 @@ public sealed class S7TagConfigModel
+ string.Join(", ", Enum.GetNames()) + ".";
}
+ // S7-016: array shape is judged against the driver's INIT guards, which THROW (failing the whole
+ // driver's init, not just this tag) for a wide-type array and for a writable Bool array. The
+ // isArray / arrayLength keys themselves belong to the TagModal's generic array controls
+ // (TagArrayConfig) and are intentionally not fields of this model, so read them off the key bag.
+ if (TagConfigJson.GetBool(_bag, "isArray"))
+ {
+ var dt = DataType;
+ if (dt is S7DataType.Int64 or S7DataType.UInt64 or S7DataType.Float64
+ or S7DataType.String or S7DataType.DateTime)
+ {
+ return $"S7 does not support {dt} arrays — use Bool (read-only), Byte, Int16, UInt16, Int32, "
+ + "UInt32 or Float32 for an array tag, or a scalar tag.";
+ }
+ if (dt == S7DataType.Bool && (Writable ?? true))
+ {
+ return "A Bool array cannot be writable (a byte-granular write would clobber neighbouring bits) — "
+ + "uncheck Writable, or use scalar Bool tags.";
+ }
+ }
+
// Gitea #554: the reader's remaining, non-enum refusal — a String tag whose 'stringLength' is
// negative or above 254 (S7 REJECTS it rather than clamping) — is not restated here. The verdict and
// the wording both come from the driver's own reader, via TagConfigParseGate.
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.Host/Drivers/DriverFactoryBootstrap.cs b/src/Server/ZB.MOM.WW.OtOpcUa.Host/Drivers/DriverFactoryBootstrap.cs
index 49794a36..df643ba0 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.Host/Drivers/DriverFactoryBootstrap.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.Host/Drivers/DriverFactoryBootstrap.cs
@@ -226,7 +226,7 @@ public static class DriverFactoryBootstrap
// task, so the Tier A 5s Subscribe budget never covers the stream's lifetime.
Driver.MTConnect.MTConnectDriverFactoryExtensions.Register(registry, loggerFactory);
Driver.OpcUaClient.OpcUaClientDriverFactoryExtensions.Register(registry, loggerFactory, secretResolver);
- Driver.S7.S7DriverFactoryExtensions.Register(registry);
+ Driver.S7.S7DriverFactoryExtensions.Register(registry, loggerFactory);
Driver.Sql.SqlDriverFactoryExtensions.Register(registry, loggerFactory);
Driver.TwinCAT.TwinCATDriverFactoryExtensions.Register(registry, loggerFactory);
}
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.IntegrationTests/S7_1500/S7_1500ArrayWriteTests.cs b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.IntegrationTests/S7_1500/S7_1500ArrayWriteTests.cs
new file mode 100644
index 00000000..90d9e13f
--- /dev/null
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.IntegrationTests/S7_1500/S7_1500ArrayWriteTests.cs
@@ -0,0 +1,52 @@
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.S7.IntegrationTests.S7_1500;
+
+///
+/// #610 item 2 (S7-016): array write round trip against the python-snap7 S7-1500 profile. Skips
+/// cleanly when the sim is absent. Uses DB1 bytes 700+ (the profile's 1024-byte DB1 has no seed
+/// there), so the writes cannot disturb another test's seeds.
+///
+[Collection(Snap7ServerCollection.Name)]
+[Trait("Category", "Integration")]
+[Trait("Device", "S7_1500")]
+public sealed class S7_1500ArrayWriteTests(Snap7ServerFixture sim)
+{
+ private static S7DriverOptions Options(string host, int port) => new()
+ {
+ Host = host,
+ Port = port,
+ CpuType = S7CpuType.S71500,
+ Rack = 0,
+ Slot = 0,
+ Timeout = TimeSpan.FromSeconds(5),
+ Probe = new S7ProbeOptions { Enabled = false },
+ RawTags = S7RawTags.Entries(
+ new S7TagDefinition("I16Arr", "DB1.DBW700", S7DataType.Int16, Writable: true, ArrayCount: 4),
+ new S7TagDefinition("F32Arr", "DB1.DBD720", S7DataType.Float32, Writable: true, ArrayCount: 3)),
+ };
+
+ /// Writes a non-trivial Int16[4] and Float32[3], then reads each back element-for-element.
+ [Fact]
+ public async Task Array_write_then_read_round_trips_through_real_S7comm()
+ {
+ if (sim.SkipReason is not null) Assert.Skip(sim.SkipReason);
+
+ await using var drv = new S7Driver(Options(sim.Host, sim.Port), "s7-arr-write");
+ await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
+
+ var i16 = new short[] { 111, -222, 3333, -4444 };
+ var f32 = new[] { 1.5f, -2.25f, 1234.5f };
+ var res = await drv.WriteAsync(
+ [new WriteRequest("I16Arr", i16), new WriteRequest("F32Arr", f32)],
+ TestContext.Current.CancellationToken);
+ res.Select(r => r.StatusCode).ShouldAllBe(c => c == 0u);
+
+ var read = await drv.ReadAsync(["I16Arr", "F32Arr"], TestContext.Current.CancellationToken);
+ read.Select(r => r.StatusCode).ShouldAllBe(c => c == 0u);
+ ((short[])read[0].Value!).ShouldBe(i16);
+ ((float[])read[1].Value!).ShouldBe(f32);
+ }
+}
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.Tests/S7ArrayWriteAndHealthTests.cs b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.Tests/S7ArrayWriteAndHealthTests.cs
new file mode 100644
index 00000000..5049ae7b
--- /dev/null
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.S7.Tests/S7ArrayWriteAndHealthTests.cs
@@ -0,0 +1,382 @@
+using Microsoft.Extensions.Logging;
+using S7.Net;
+using Shouldly;
+using Xunit;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.Hosting;
+using S7NetDataType = global::S7.Net.DataType;
+using S7DataItem = global::S7.Net.Types.DataItem;
+
+namespace ZB.MOM.WW.OtOpcUa.Driver.S7.Tests;
+
+///
+/// #602 / #610 S7 items: array write path (S7-016), connect backoff (STAB-21), the write-pass
+/// worst-state-wins accumulator (STAB-22) and the factory logger (CONV-3). All against an
+/// in-memory — no live PLC, no fixture.
+///
+[Trait("Category", "Unit")]
+public sealed class S7ArrayWriteAndHealthTests
+{
+ private const uint BadTypeMismatch = 0x80740000u;
+ private const uint BadNotSupported = 0x803D0000u;
+
+ private static S7TagDefinition Arr(S7DataType dt, string addr, int count, bool writable = true) =>
+ new("Arr", addr, dt, Writable: writable, ArrayCount: count);
+
+ private static S7DriverOptions Options(params S7TagDefinition[] tags) => new()
+ {
+ Host = "192.0.2.1",
+ Timeout = TimeSpan.FromMilliseconds(250),
+ Probe = new S7ProbeOptions { Enabled = false },
+ RawTags = S7RawTags.Entries(tags),
+ };
+
+ // ---- pure codec ----
+
+ /// Encode is the exact inverse of for every supported element type.
+ [Theory]
+ [InlineData(S7DataType.Byte, "DB1.DBB0")]
+ [InlineData(S7DataType.Int16, "DB1.DBW0")]
+ [InlineData(S7DataType.UInt16, "DB1.DBW0")]
+ [InlineData(S7DataType.Int32, "DB1.DBD0")]
+ [InlineData(S7DataType.UInt32, "DB1.DBD0")]
+ [InlineData(S7DataType.Float32, "DB1.DBD0")]
+ public void EncodeArrayBlock_round_trips_through_DecodeArrayBlock(S7DataType dt, string addrText)
+ {
+ var tag = Arr(dt, addrText, 3);
+ var addr = S7AddressParser.Parse(addrText);
+ object source = dt switch
+ {
+ S7DataType.Byte => new byte[] { 1, 200, 255 },
+ S7DataType.Int16 => new short[] { -1, 0, 32000 },
+ S7DataType.UInt16 => new ushort[] { 1, 0, 65535 },
+ S7DataType.Int32 => new[] { -5, 0, int.MaxValue },
+ S7DataType.UInt32 => new uint[] { 1, 0, uint.MaxValue },
+ _ => new[] { -1.5f, 0f, 3.25f },
+ };
+
+ var block = S7Driver.EncodeArrayBlock(tag, addr, source);
+
+ block.Length.ShouldBe(3 * S7Driver.ElementByteSize(addr.Size));
+ S7Driver.DecodeArrayBlock(tag, addr, block).ShouldBe(source);
+ }
+
+ /// Big-endian layout is pinned byte-for-byte for Int16.
+ [Fact]
+ public void EncodeArrayBlock_is_big_endian()
+ {
+ var tag = Arr(S7DataType.Int16, "DB1.DBW0", 2);
+ S7Driver.EncodeArrayBlock(tag, S7AddressParser.Parse("DB1.DBW0"), new short[] { 0x0102, -2 })
+ .ShouldBe(new byte[] { 0x01, 0x02, 0xFF, 0xFE });
+ }
+
+ /// A non-array, a string, a wrong length and an unconvertible element are client errors, not comms faults.
+ [Fact]
+ public void EncodeArrayBlock_rejects_wrongly_shaped_values()
+ {
+ var tag = Arr(S7DataType.Int16, "DB1.DBW0", 2);
+ var addr = S7AddressParser.Parse("DB1.DBW0");
+
+ Should.Throw(() => S7Driver.EncodeArrayBlock(tag, addr, (short)1));
+ Should.Throw(() => S7Driver.EncodeArrayBlock(tag, addr, "ab"));
+ Should.Throw(() => S7Driver.EncodeArrayBlock(tag, addr, new short[] { 1 }));
+ Should.Throw(() => S7Driver.EncodeArrayBlock(tag, addr, new[] { 1, 2, 3 }));
+ Should.Throw(() => S7Driver.EncodeArrayBlock(tag, addr, new object[] { 1, 70000 })); // overflow
+ Should.Throw(() => S7Driver.EncodeArrayBlock(tag, addr, new object[] { 1, "x" })); // format
+ }
+
+ /// Bool and wide-type arrays are refused with NotSupported (BadNotSupported on the wire).
+ [Theory]
+ [InlineData(S7DataType.Bool, "DB1.DBX0.0")]
+ [InlineData(S7DataType.Int64, "DB1.DBB0")]
+ [InlineData(S7DataType.String, "DB1.DBB0")]
+ public void EncodeArrayBlock_refuses_bool_and_wide_arrays(S7DataType dt, string addrText)
+ {
+ Should.Throw(() => S7Driver.EncodeArrayBlock(
+ Arr(dt, addrText, 2), S7AddressParser.Parse(addrText), new object[] { 1, 2 }));
+ }
+
+ // ---- WriteAsync array path ----
+
+ ///
+ /// A valid array write issues exactly ONE contiguous WriteBytes at the tag's DB/offset
+ /// (S7-016) and reports Good. The bytes are the decode inverse, so a following read returns the value.
+ ///
+ [Fact]
+ public async Task Write_array_issues_one_contiguous_block_write()
+ {
+ var factory = new RecordingFactory();
+ using var drv = new S7Driver(Options(Arr(S7DataType.Int16, "DB5.DBW10", 3)), "s7-arr-write", factory);
+ await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
+
+ var res = await drv.WriteAsync([new WriteRequest("Arr", new short[] { 1, 2, 3 })], TestContext.Current.CancellationToken);
+
+ res[0].StatusCode.ShouldBe(0u);
+ var w = factory.Created[0].BlockWrites.ShouldHaveSingleItem();
+ w.Area.ShouldBe(S7NetDataType.DataBlock);
+ w.Db.ShouldBe(5);
+ w.Start.ShouldBe(10);
+ w.Bytes.ShouldBe(new byte[] { 0, 1, 0, 2, 0, 3 });
+ factory.Created[0].ScalarWrites.ShouldBe(0);
+ drv.GetHealth().State.ShouldBe(DriverState.Healthy);
+ }
+
+ ///
+ /// A wrong-length array is BadTypeMismatch, writes nothing and leaves health untouched; the
+ /// positive control is the valid write in the same batch landing.
+ ///
+ [Fact]
+ public async Task Write_array_with_wrong_length_is_BadTypeMismatch_and_not_a_health_event()
+ {
+ var factory = new RecordingFactory();
+ using var drv = new S7Driver(Options(Arr(S7DataType.Int16, "DB1.DBW0", 3)), "s7-arr-len", factory);
+ await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
+
+ var res = await drv.WriteAsync(
+ [new WriteRequest("Arr", new short[] { 1, 2 }), new WriteRequest("Arr", new short[] { 7, 8, 9 })],
+ TestContext.Current.CancellationToken);
+
+ res[0].StatusCode.ShouldBe(BadTypeMismatch);
+ res[1].StatusCode.ShouldBe(0u);
+ factory.Created[0].BlockWrites.Count.ShouldBe(1); // only the valid one reached the wire
+ drv.GetHealth().State.ShouldBe(DriverState.Healthy);
+ }
+
+ // ---- STAB-21 connect backoff ----
+
+ ///
+ /// A dead PLC costs ONE connect attempt per backoff window, not one per read; the window grows
+ /// (1 s then 2 s), and a successful connect clears it so recovery is immediate.
+ ///
+ [Fact]
+ public async Task Dead_plc_costs_one_connect_attempt_per_backoff_window()
+ {
+ var factory = new RecordingFactory();
+ using var drv = new S7Driver(Options(new S7TagDefinition("W0", "DB1.DBW0", S7DataType.UInt16)), "s7-backoff", factory);
+ var now = new DateTime(2026, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+ drv.BackoffClock = () => now;
+ await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
+ factory.Created.Count.ShouldBe(1);
+
+ // Drop the link; every subsequent open is refused.
+ factory.Created[0].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "dropped");
+ factory.OpenThrows = new PlcException(ErrorCode.ConnectionError, "down");
+ await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken); // marks dead
+
+ // First attempt after the drop: really tries (and fails), opening a 1 s window.
+ (await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken))[0].StatusCode.ShouldNotBe(0u);
+ factory.Created.Count.ShouldBe(2);
+
+ // Ten more reads inside the window: no further connect attempt, still a Bad result.
+ for (var i = 0; i < 10; i++)
+ (await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken))[0].StatusCode.ShouldNotBe(0u);
+ factory.Created.Count.ShouldBe(2);
+ drv.GetHealth().State.ShouldBe(DriverState.Degraded);
+
+ // Window elapses -> exactly one more attempt (fails -> 2 s window).
+ now += TimeSpan.FromSeconds(1.1);
+ await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
+ factory.Created.Count.ShouldBe(3);
+ now += TimeSpan.FromSeconds(1.1); // inside the doubled window
+ await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
+ factory.Created.Count.ShouldBe(3);
+
+ // PLC returns; once the window passes the next read reconnects and the window is cleared.
+ factory.OpenThrows = null;
+ now += TimeSpan.FromSeconds(5);
+ (await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);
+ factory.Created.Count.ShouldBe(4);
+ drv.GetHealth().State.ShouldBe(DriverState.Healthy);
+
+ // A fresh drop reconnects immediately (no residual window).
+ factory.Created[3].NextReadThrows = new PlcException(ErrorCode.ConnectionError, "dropped again");
+ await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken);
+ (await drv.ReadAsync(["W0"], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);
+ factory.Created.Count.ShouldBe(5);
+ }
+
+ // ---- STAB-22 write-pass worst-state-wins ----
+
+ private static async Task<(S7Driver Drv, RecordingFactory Factory)> TwoTagDriver()
+ {
+ var factory = new RecordingFactory();
+ var drv = new S7Driver(Options(
+ new S7TagDefinition("A", "DB1.DBW0", S7DataType.UInt16, Writable: true),
+ new S7TagDefinition("B", "DB1.DBW2", S7DataType.UInt16, Writable: true),
+ new S7TagDefinition("C", "DB1.DBW4", S7DataType.UInt16, Writable: true)), "s7-writepass", factory);
+ await drv.InitializeAsync("{}", TestContext.Current.CancellationToken);
+ return (drv, factory);
+ }
+
+ ///
+ /// Access-denied (Faulted) followed by a generic failure (Degraded) and a success in ONE batch
+ /// must report Faulted with the access-denied message - not whichever item came last.
+ ///
+ [Fact]
+ public async Task Write_batch_reports_worst_state_not_last_item()
+ {
+ var (drv, factory) = await TwoTagDriver();
+ using var _ = drv;
+ factory.Created[0].WriteFaults["DB1.DBW0"] = new PlcException(ErrorCode.WriteData, "Accessing object not allowed");
+ factory.Created[0].WriteFaults["DB1.DBW2"] = new IOException("socket glitch");
+
+ var res = await drv.WriteAsync(
+ [new WriteRequest("A", (ushort)1), new WriteRequest("B", (ushort)2), new WriteRequest("C", (ushort)3)],
+ TestContext.Current.CancellationToken);
+
+ res[2].StatusCode.ShouldBe(0u);
+ var h = drv.GetHealth();
+ h.State.ShouldBe(DriverState.Faulted);
+ h.LastError.ShouldNotBeNull().ShouldContain("PUT/GET");
+ }
+
+ ///
+ /// A clean READ pass must not erase the write-side Faulted; the next write that succeeds clears
+ /// it, after which a read pass reports Healthy again.
+ ///
+ [Fact]
+ public async Task Read_pass_does_not_erase_write_fault_until_a_write_succeeds()
+ {
+ var (drv, factory) = await TwoTagDriver();
+ using var _ = drv;
+ var plc = factory.Created[0];
+ plc.WriteFaults["DB1.DBW0"] = new PlcException(ErrorCode.WriteData, "Accessing object not allowed");
+ await drv.WriteAsync([new WriteRequest("A", (ushort)1)], TestContext.Current.CancellationToken);
+ drv.GetHealth().State.ShouldBe(DriverState.Faulted);
+
+ // Clean read of a different tag - reads work against a write-protected CPU.
+ var read = await drv.ReadAsync(["B"], TestContext.Current.CancellationToken);
+ read[0].StatusCode.ShouldBe(0u);
+ var h = drv.GetHealth();
+ h.State.ShouldBe(DriverState.Faulted); // not erased
+ h.LastSuccessfulRead.ShouldNotBeNull(); // but the read still advanced the watchdog evidence
+
+ // A write that gets through retires the fault ...
+ await drv.WriteAsync([new WriteRequest("B", (ushort)2)], TestContext.Current.CancellationToken);
+ drv.GetHealth().State.ShouldBe(DriverState.Healthy);
+
+ // ... and the next read pass stays Healthy (the sticky state is really gone).
+ (await drv.ReadAsync(["B"], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);
+ drv.GetHealth().State.ShouldBe(DriverState.Healthy);
+ }
+
+ /// A transient (Degraded) write failure is still erased by a clean read, as before.
+ [Fact]
+ public async Task Degraded_write_failure_is_still_cleared_by_a_clean_read()
+ {
+ var (drv, factory) = await TwoTagDriver();
+ using var _ = drv;
+ factory.Created[0].WriteFaults["DB1.DBW0"] = new IOException("glitch");
+ await drv.WriteAsync([new WriteRequest("A", (ushort)1)], TestContext.Current.CancellationToken);
+ drv.GetHealth().State.ShouldBe(DriverState.Degraded);
+
+ (await drv.ReadAsync(["B"], TestContext.Current.CancellationToken))[0].StatusCode.ShouldBe(0u);
+ drv.GetHealth().State.ShouldBe(DriverState.Healthy);
+ }
+
+ // ---- CONV-3 ----
+
+ ///
+ /// The registered factory builds drivers on the host logger: a failed connect reaches the
+ /// supplied . Before CONV-3 the factory took no logger and the driver ran on the null logger.
+ ///
+ [Fact]
+ public async Task Factory_threads_the_logger_factory_into_the_driver()
+ {
+ const string Json = """{"host":"192.0.2.1","timeoutMs":200}""";
+
+ var withLogger = new CapturingLoggerFactory();
+ var registry = new DriverFactoryRegistry();
+ S7DriverFactoryExtensions.Register(registry, withLogger);
+ var drv = registry.TryGet(S7DriverFactoryExtensions.DriverTypeName)!("s7-logs", Json);
+ try { await drv.InitializeAsync(Json, TestContext.Current.CancellationToken); } catch { /* unreachable host by design */ }
+ withLogger.Messages.ShouldContain(m => m.Contains("connect failed", StringComparison.OrdinalIgnoreCase));
+ }
+
+ private sealed class CapturingLoggerFactory : ILoggerFactory
+ {
+ public List Messages { get; } = [];
+ public void AddProvider(ILoggerProvider provider) { }
+ public ILogger CreateLogger(string categoryName) => new Capture(this);
+ public void Dispose() { }
+
+ private sealed class Capture(CapturingLoggerFactory owner) : ILogger
+ {
+ public IDisposable? BeginScope(TState state) where TState : notnull => null;
+ public bool IsEnabled(LogLevel logLevel) => true;
+ public void Log(LogLevel logLevel, EventId eventId, TState state, Exception? exception,
+ Func formatter)
+ {
+ lock (owner.Messages) owner.Messages.Add(formatter(state, exception));
+ }
+ }
+ }
+
+ // ---- in-memory PLC ----
+
+ private sealed class RecordingFactory : IS7PlcFactory
+ {
+ public List Created { get; } = [];
+
+ /// When set, every connection created from now on throws this from OpenAsync.
+ public Exception? OpenThrows { get; set; }
+
+ public IS7Plc Create(S7CpuType cpuType, string host, int port, short rack, short slot, TimeSpan timeout)
+ {
+ var plc = new RecordingPlc { OpenThrowsAlways = OpenThrows };
+ Created.Add(plc);
+ return plc;
+ }
+ }
+
+ private sealed class RecordingPlc : IS7Plc
+ {
+ public bool IsConnected { get; private set; }
+ public Exception? OpenThrowsAlways { get; init; }
+ public Exception? NextReadThrows { get; set; }
+ public Dictionary WriteFaults { get; } = new(StringComparer.Ordinal);
+ public List<(S7NetDataType Area, int Db, int Start, byte[] Bytes)> BlockWrites { get; } = [];
+ public int ScalarWrites { get; private set; }
+
+ public Task OpenAsync(CancellationToken cancellationToken)
+ {
+ if (OpenThrowsAlways is { } ex) throw ex;
+ IsConnected = true;
+ return Task.CompletedTask;
+ }
+
+ public void Close() => IsConnected = false;
+
+ public Task