Files
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
AB Legacy PR 3 — ITagDiscovery + ISubscribable + IHostConnectivityProbe + IPerCallHostResolver. Fills out the AbLegacy capability surface — the driver now implements the same 7-interface set as AbCip (IDriver + IReadable + IWritable + ITagDiscovery + ISubscribable + IHostConnectivityProbe + IPerCallHostResolver). ITagDiscovery emits pre-declared tags under an AbLegacy root folder with a per-device sub-folder keyed on HostAddress (DeviceName fallback to HostAddress when null). Writable tags surface as SecurityClassification.Operate, non-writable as ViewOnly. No controller-side enumeration — PCCC has no @tags equivalent on SLC / MicroLogix / PLC-5 (symbol table isn't exposed the way Logix exposes it), so the pre-declared path is the only discovery mechanism. ISubscribable consumes the shared PollGroupEngine extracted in AB CIP PR 1 — reader delegate points at ReadAsync (already handles lazy runtime init + caching), onChange bridges into the driver's OnDataChange event. 100ms interval floor. Initial-data push on first poll. Makes AbLegacy the third consumer of PollGroupEngine (after Modbus and AbCip). IHostConnectivityProbe — per-device probe loop when ProbeOptions.Enabled + ProbeAddress configured (defaults to S:0 status file word 0). Lazy-init on first tick, re-init on wire failure (destroyed native handle gets recreated rather than silently staying broken). Success transitions device to Running, exception to Stopped, same-state spurious event guard under per-device lock. GetHostStatuses returns one entry per device with current state + last-change timestamp for Admin /hosts surfacing. IPerCallHostResolver maps tag full-ref → DeviceHostAddress for the Phase 6.1 (DriverInstanceId, ResolvedHostName) bulkhead/breaker keying per plan decision #144. Unknown refs fall back to first device's address (invoker handles at capability level as BadNodeIdUnknown); no devices → DriverInstanceId. ShutdownAsync cancels + disposes each probe CTS, disposes PollGroupEngine cancelling active subscriptions, disposes every cached runtime. DeviceState gains ProbeLock / HostState / HostStateChangedUtc / ProbeCts / ProbeInitialized matching AbCip's DeviceState shape. 10 new unit tests in AbLegacyCapabilityTests covering — pre-declared tags emit under AbLegacy/device folder with correct SecurityClassification, subscription initial poll raises OnDataChange with correct value, unsubscribe halts polling (value change post-unsub produces no further events), GetHostStatuses returns one entry per device, probe Running transition on successful read, probe Stopped transition on read exception, probe disabled when ProbeAddress null, ResolveHost returns declared device for known tag, falls back to first device for unknown, falls back to DriverInstanceId when no devices. Total AbLegacy unit tests now 92/92 passing (+10 from PR 2's 82); full solution builds 0 errors; AbCip + Modbus + other drivers untouched. AB Legacy driver now complete end-to-end — SLC 500 / MicroLogix / PLC-5 / LogixPccc all shippable with read / write / discovery / subscribe / probe / host-resolve, feature-parity with AbCip minus IAlarmSource (same deferral per plan).
AB Legacy PR 2 — IReadable + IWritable. IAbLegacyTagRuntime + IAbLegacyTagFactory abstraction mirrors IAbCipTagRuntime from AbCip PR 3. LibplctagLegacyTagRuntime default implementation wraps libplctag.Tag with Protocol=ab_eip + PlcType dispatched from the profile's libplctag attribute (Slc500/MicroLogix/Plc5/LogixPccc) — libplctag routes PCCC-over-EIP internally based on PlcType, so our layer just forwards the atomic type to Get/Set calls. DecodeValue handles Bit (GetBit when bitIndex is set, else GetInt8!=0), Int/AnalogInt (GetInt16 widened to int), Long (GetInt32), Float (GetFloat32), String (GetString), TimerElement/CounterElement/ControlElement (GetInt32 — sub-element selection is in the libplctag tag name like T4:0.ACC, PLC-side decode picks the right slot). EncodeValue handles the same types; bit-within-word writes throw NotSupportedException pointing at follow-up task #181 (same read-modify-write gap as Modbus BitInRegister). AbLegacyDriver implements IReadable + IWritable with the exact same shape as AbCip PR 3-4 — per-tag lazy runtime init via EnsureTagRuntimeAsync cached in DeviceState.Runtimes dict, ordered-snapshot results, health surface updates. Exception table — OperationCanceledException rethrows, NotSupportedException → BadNotSupported, FormatException/InvalidCastException → BadTypeMismatch (guard pattern C# 11 syntax), OverflowException → BadOutOfRange, anything else → BadCommunicationError. ShutdownAsync disposes every cached runtime so the native tag handles get released. 14 new unit tests in AbLegacyReadWriteTests covering unknown ref → BadNodeIdUnknown, successful N-file read with Good status + captured value, repeat-read reuses cached runtime (init count 1 across 2 reads), libplctag non-zero status mapping (-14 → BadNodeIdUnknown), read exception → BadCommunicationError + Degraded health, batched reads preserve order across N/F/ST types, TagCreateParams composition (gateway/port/path/slc500 attribute/tag-name), non-writable tag → BadNotWritable, successful write encodes + flushes, bit-within-word → BadNotSupported (RmwThrowingFake mirrors LibplctagLegacyTagRuntime's runtime check), write exception → BadCommunicationError, batch preserves order across success+fail+unknown, cancellation propagates, ShutdownAsync disposes runtimes. Total AbLegacy unit tests now 82/82 passing (+14 from PR 1's 68). Full solution builds 0 errors; Modbus + AbCip + other drivers untouched.
AB Legacy PR 2 — IReadable + IWritable. IAbLegacyTagRuntime + IAbLegacyTagFactory abstraction mirrors IAbCipTagRuntime from AbCip PR 3. LibplctagLegacyTagRuntime default implementation wraps libplctag.Tag with Protocol=ab_eip + PlcType dispatched from the profile's libplctag attribute (Slc500/MicroLogix/Plc5/LogixPccc) — libplctag routes PCCC-over-EIP internally based on PlcType, so our layer just forwards the atomic type to Get/Set calls. DecodeValue handles Bit (GetBit when bitIndex is set, else GetInt8!=0), Int/AnalogInt (GetInt16 widened to int), Long (GetInt32), Float (GetFloat32), String (GetString), TimerElement/CounterElement/ControlElement (GetInt32 — sub-element selection is in the libplctag tag name like T4:0.ACC, PLC-side decode picks the right slot). EncodeValue handles the same types; bit-within-word writes throw NotSupportedException pointing at follow-up task #181 (same read-modify-write gap as Modbus BitInRegister). AbLegacyDriver implements IReadable + IWritable with the exact same shape as AbCip PR 3-4 — per-tag lazy runtime init via EnsureTagRuntimeAsync cached in DeviceState.Runtimes dict, ordered-snapshot results, health surface updates. Exception table — OperationCanceledException rethrows, NotSupportedException → BadNotSupported, FormatException/InvalidCastException → BadTypeMismatch (guard pattern C# 11 syntax), OverflowException → BadOutOfRange, anything else → BadCommunicationError. ShutdownAsync disposes every cached runtime so the native tag handles get released. 14 new unit tests in AbLegacyReadWriteTests covering unknown ref → BadNodeIdUnknown, successful N-file read with Good status + captured value, repeat-read reuses cached runtime (init count 1 across 2 reads), libplctag non-zero status mapping (-14 → BadNodeIdUnknown), read exception → BadCommunicationError + Degraded health, batched reads preserve order across N/F/ST types, TagCreateParams composition (gateway/port/path/slc500 attribute/tag-name), non-writable tag → BadNotWritable, successful write encodes + flushes, bit-within-word → BadNotSupported (RmwThrowingFake mirrors LibplctagLegacyTagRuntime's runtime check), write exception → BadCommunicationError, batch preserves order across success+fail+unknown, cancellation propagates, ShutdownAsync disposes runtimes. Total AbLegacy unit tests now 82/82 passing (+14 from PR 1's 68). Full solution builds 0 errors; Modbus + AbCip + other drivers untouched.