Files
Joseph Doherty
ece530d133
AB CIP UDT Template Object shape reader. Closes the shape-reader half of task #179. CipTemplateObjectDecoder (pure-managed) parses the Read Template blob per Rockwell CIP Vol 1 + libplctag ab/cip.c handle_read_template_reply — 12-byte header (u16 member_count + u16 struct_handle + u32 instance_size + u32 member_def_size) followed by memberCount × 8-byte member blocks (u16 info with bit-15 struct flag + lower-12-bit type code matching the Symbol Object encoding, u16 array_size, u32 struct_offset) followed by semicolon-terminated strings (UDT name first, then one per member). ParseSemicolonTerminatedStrings handles the observed firmware variations — name;\0 vs name; delimiters, optional null/space padding after the semicolon, trailing-name-without-semicolon corner case. Struct-flag members decode as AbCipDataType.Structure; unknown atomic codes fall back to Structure so the shape remains valid even with unrecognised members. Zero member count + short buffer both return null; missing member names yield <member_N> placeholders. IAbCipTemplateReader + IAbCipTemplateReaderFactory abstraction — one call per template instance id returning the raw blob. LibplctagTemplateReader is the production implementation creating a libplctag Tag with name @udt/{templateId} + handing the buffer to the decoder. AbCipDriver ctor gains optional templateReaderFactory parameter (defaults to LibplctagTemplateReaderFactory) + new internal FetchUdtShapeAsync that — checks AbCipTemplateCache first, misses call the reader + decode + cache, template-read exceptions + decode failures return null so callers can fall back to declaration-driven fan-out without the whole discovery blowing up. OperationCanceledException rethrows for shutdown propagation. Unknown device host returns null without attempting a fetch. FlushOptionalCachesAsync empties the cache so a subsequent fetch re-reads. 16 new decoder tests — simple two-member UDT, struct-member flag → Structure, array member ArrayLength, 6-member mixed-type with correct offsets, unknown type code → Structure, zero member count → null, short buffer → null, missing member name → placeholder, ParseSemicolonTerminatedStrings theory across 5 shapes. 6 new AbCipFetchUdtShapeTests exercising the driver integration via reflection (method is internal) — happy-path decode + cache, different template ids get separate fetches, unknown device → null without reader creation, decode failure returns null + doesn't cache (next call retries), reader exception returns null, FlushOptionalCachesAsync clears the cache. Total AbCip unit tests now 211/211 passing (+19 from the @tags merge's 192); full solution builds 0 errors; other drivers untouched. Whole-UDT read optimization (single libplctag call returning the packed buffer + client-side member decode using the template offsets) is left as a follow-up — requires rethinking the per-tag read path + careful hardware validation; current per-member fan-out still works correctly, just with N round-trips instead of 1.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
AB CIP PR 2 — scaffolding + Core (AbCipDriver skeleton + libplctag binding + host / tag-path / data-type / status-code parsers + per-family profiles + SafeHandle wrapper + test harness). Ships everything needed to stand up the driver project as a compiling assembly with no wire calls yet — PR 3 adds IReadable against ab_server which is the first PR that actually touches the native library. Project reference shape matches Modbus / OpcUaClient / S7 (only Core.Abstractions, no Core / Configuration / Polly) so the driver stays lean and doesn't drag EF Core into every deployment that wants AB support. libplctag 1.5.2 pinned (1.6.x only exists as alpha — stable 1.5 series covers ControlLogix / CompactLogix / Micro800 / SLC500 / PLC-5 / MicroLogix which matches plan decision #11 family coverage). libplctag.NativeImport arrives transitively. AbCipHostAddress parses ab://gateway[:port]/cip-path canonical strings end-to-end: handles hostname or IP gateway, optional explicit port (default 44818 EtherNet-IP reserved), CIP path including bridged routes (1,2,2,10.0.0.10,1,0), empty path for Micro800 / MicroLogix without backplane routing, case-insensitive scheme, default-port stripping in canonical form for round-trip stability. Opaque string survives straight into libplctag's gateway / path attributes so no translation layer at wire time. AbCipTagPath handles the full Logix symbolic tag surface — controller-scope (Motor1_Speed), program-scope (Program:MainProgram.StepIndex), structured member access (Motor1.Speed.Setpoint), multi-dim array subscripts (Matrix[1,2,3]), bit-within-DINT via .N syntax (Flags.3, Motor.Status.12) with valid range 0-31 per Logix 5000 General Instructions Reference. Structural capture so PR 6 UDT work can walk the path against a cached template without reparsing. Rejects malformed shapes (empty scopes, ident starting with digit, spaces, empty/negative/non-numeric subscripts, unbalanced brackets, leading / trailing dots). Round-trips via ToLibplctagName producing the exact string libplctag's name attribute expects. AbCipDataType mirrors ModbusDataType shape — atomic Bool / SInt / Int / DInt / LInt / USInt / UInt / UDInt / ULInt / Real / LReal / String / Dt plus a Structure marker for UDT-typed tags (resolved via CIP Template Object at discovery time in PR 5/6). ToDriverDataType adapter follows the Modbus widening convention for unsigned + 64-bit until DriverDataType picks those up. AbCipStatusMapper covers the CIP general-status values an AB PLC actually returns during normal operation (0x00/0x04/0x05/0x06/0x08/0x0A/0x0B/0x0E/0x10/0x13/0x16) + libplctag PLCTAG_STATUS_* codes (0, >0 pending, negative error families). Mirrors ModbusDriver.MapModbusExceptionToStatus so Admin UI status displays stay uniform across drivers. PlcTagHandle is a SafeHandle around the int32 native tag ID with plc_tag_destroy slot wired as a no-op for PR 2 (P/Invoke DllImport arrives with PR 3 when the wire calls land). Lifetime guaranteed by the SafeHandle finalizer — every leaked handle gets cleaned up even when the owner is GC'd without explicit Dispose. IsInvalid when native ID <= 0 so destroying a negative (error) handle never happens. Critical because driver-specs.md §3 flags libplctag native heap as invisible to GetMemoryFootprint — leaked handles directly feed the Tier-B recycle trigger. AbCipDriverOptions captures the multi-device shape — one driver instance can talk to N PLCs via Devices[] (each with HostAddress + PlcFamily + optional DeviceName); Tags[] references devices by HostAddress as the cross-key; AbCipProbeOptions + driver-wide Timeout. AbCipDriver implements IDriver only — InitializeAsync parses every device's HostAddress and selects its PlcFamilyProfile (fails fast on malformed strings via InvalidOperationException → Faulted health), per-device state cached in a DeviceState record with parsed address + profile + empty TagHandles dict for later PRs. ReinitializeAsync is the Tier-B escape hatch — shuts down every device, disposes every PlcTagHandle via SafeHandle lifetime, reinitializes from options. ShutdownAsync clears the device dict and flips health to Unknown. PlcFamilies/AbCipPlcFamilyProfile gives four baseline profiles — ControlLogix (4002 ConnectionSize, path 1,0, Large Forward Open + request packing + connected messaging, FW20+ baseline), CompactLogix (narrower 504 default for 5069-L3x safety), Micro800 (488 cap, empty path, unconnected-only, no request packing), GuardLogix (shares ControlLogix wire protocol — safety partition is tag-level, surfaced as ViewOnly in PR 12). Tests — 76 new cases across 4 test classes — AbCipHostAddressTests (10 valid shapes, 10 invalid shapes, ToString canonicalization, round-trip stability), AbCipTagPathTests (18 cases including multi-scope / multi-member / multi-subscript / bit-in-DINT / rejected shapes / underscore idents / round-trip), AbCipStatusMapperTests (12 CIP + 8 libplctag codes), AbCipDriverTests (IDriver lifecycle + multi-device init + malformed-address fault + per-family profile lookup + PlcTagHandle invalid/dispose idempotency + AbCipDataType mapping). Full solution builds 0 errors; 254 warnings are pre-existing xUnit1051 CancellationToken hints outside this PR. Solution file updated to include both new projects. Unblocks PR 3 (IReadable against ab_server) which is the first PR to exercise the native library end-to-end.
AB CIP PR 2 — scaffolding + Core (AbCipDriver skeleton + libplctag binding + host / tag-path / data-type / status-code parsers + per-family profiles + SafeHandle wrapper + test harness). Ships everything needed to stand up the driver project as a compiling assembly with no wire calls yet — PR 3 adds IReadable against ab_server which is the first PR that actually touches the native library. Project reference shape matches Modbus / OpcUaClient / S7 (only Core.Abstractions, no Core / Configuration / Polly) so the driver stays lean and doesn't drag EF Core into every deployment that wants AB support. libplctag 1.5.2 pinned (1.6.x only exists as alpha — stable 1.5 series covers ControlLogix / CompactLogix / Micro800 / SLC500 / PLC-5 / MicroLogix which matches plan decision #11 family coverage). libplctag.NativeImport arrives transitively. AbCipHostAddress parses ab://gateway[:port]/cip-path canonical strings end-to-end: handles hostname or IP gateway, optional explicit port (default 44818 EtherNet-IP reserved), CIP path including bridged routes (1,2,2,10.0.0.10,1,0), empty path for Micro800 / MicroLogix without backplane routing, case-insensitive scheme, default-port stripping in canonical form for round-trip stability. Opaque string survives straight into libplctag's gateway / path attributes so no translation layer at wire time. AbCipTagPath handles the full Logix symbolic tag surface — controller-scope (Motor1_Speed), program-scope (Program:MainProgram.StepIndex), structured member access (Motor1.Speed.Setpoint), multi-dim array subscripts (Matrix[1,2,3]), bit-within-DINT via .N syntax (Flags.3, Motor.Status.12) with valid range 0-31 per Logix 5000 General Instructions Reference. Structural capture so PR 6 UDT work can walk the path against a cached template without reparsing. Rejects malformed shapes (empty scopes, ident starting with digit, spaces, empty/negative/non-numeric subscripts, unbalanced brackets, leading / trailing dots). Round-trips via ToLibplctagName producing the exact string libplctag's name attribute expects. AbCipDataType mirrors ModbusDataType shape — atomic Bool / SInt / Int / DInt / LInt / USInt / UInt / UDInt / ULInt / Real / LReal / String / Dt plus a Structure marker for UDT-typed tags (resolved via CIP Template Object at discovery time in PR 5/6). ToDriverDataType adapter follows the Modbus widening convention for unsigned + 64-bit until DriverDataType picks those up. AbCipStatusMapper covers the CIP general-status values an AB PLC actually returns during normal operation (0x00/0x04/0x05/0x06/0x08/0x0A/0x0B/0x0E/0x10/0x13/0x16) + libplctag PLCTAG_STATUS_* codes (0, >0 pending, negative error families). Mirrors ModbusDriver.MapModbusExceptionToStatus so Admin UI status displays stay uniform across drivers. PlcTagHandle is a SafeHandle around the int32 native tag ID with plc_tag_destroy slot wired as a no-op for PR 2 (P/Invoke DllImport arrives with PR 3 when the wire calls land). Lifetime guaranteed by the SafeHandle finalizer — every leaked handle gets cleaned up even when the owner is GC'd without explicit Dispose. IsInvalid when native ID <= 0 so destroying a negative (error) handle never happens. Critical because driver-specs.md §3 flags libplctag native heap as invisible to GetMemoryFootprint — leaked handles directly feed the Tier-B recycle trigger. AbCipDriverOptions captures the multi-device shape — one driver instance can talk to N PLCs via Devices[] (each with HostAddress + PlcFamily + optional DeviceName); Tags[] references devices by HostAddress as the cross-key; AbCipProbeOptions + driver-wide Timeout. AbCipDriver implements IDriver only — InitializeAsync parses every device's HostAddress and selects its PlcFamilyProfile (fails fast on malformed strings via InvalidOperationException → Faulted health), per-device state cached in a DeviceState record with parsed address + profile + empty TagHandles dict for later PRs. ReinitializeAsync is the Tier-B escape hatch — shuts down every device, disposes every PlcTagHandle via SafeHandle lifetime, reinitializes from options. ShutdownAsync clears the device dict and flips health to Unknown. PlcFamilies/AbCipPlcFamilyProfile gives four baseline profiles — ControlLogix (4002 ConnectionSize, path 1,0, Large Forward Open + request packing + connected messaging, FW20+ baseline), CompactLogix (narrower 504 default for 5069-L3x safety), Micro800 (488 cap, empty path, unconnected-only, no request packing), GuardLogix (shares ControlLogix wire protocol — safety partition is tag-level, surfaced as ViewOnly in PR 12). Tests — 76 new cases across 4 test classes — AbCipHostAddressTests (10 valid shapes, 10 invalid shapes, ToString canonicalization, round-trip stability), AbCipTagPathTests (18 cases including multi-scope / multi-member / multi-subscript / bit-in-DINT / rejected shapes / underscore idents / round-trip), AbCipStatusMapperTests (12 CIP + 8 libplctag codes), AbCipDriverTests (IDriver lifecycle + multi-device init + malformed-address fault + per-family profile lookup + PlcTagHandle invalid/dispose idempotency + AbCipDataType mapping). Full solution builds 0 errors; 254 warnings are pre-existing xUnit1051 CancellationToken hints outside this PR. Solution file updated to include both new projects. Unblocks PR 3 (IReadable against ab_server) which is the first PR to exercise the native library end-to-end.
AB CIP UDT Template Object shape reader. Closes the shape-reader half of task #179. CipTemplateObjectDecoder (pure-managed) parses the Read Template blob per Rockwell CIP Vol 1 + libplctag ab/cip.c handle_read_template_reply — 12-byte header (u16 member_count + u16 struct_handle + u32 instance_size + u32 member_def_size) followed by memberCount × 8-byte member blocks (u16 info with bit-15 struct flag + lower-12-bit type code matching the Symbol Object encoding, u16 array_size, u32 struct_offset) followed by semicolon-terminated strings (UDT name first, then one per member). ParseSemicolonTerminatedStrings handles the observed firmware variations — name;\0 vs name; delimiters, optional null/space padding after the semicolon, trailing-name-without-semicolon corner case. Struct-flag members decode as AbCipDataType.Structure; unknown atomic codes fall back to Structure so the shape remains valid even with unrecognised members. Zero member count + short buffer both return null; missing member names yield <member_N> placeholders. IAbCipTemplateReader + IAbCipTemplateReaderFactory abstraction — one call per template instance id returning the raw blob. LibplctagTemplateReader is the production implementation creating a libplctag Tag with name @udt/{templateId} + handing the buffer to the decoder. AbCipDriver ctor gains optional templateReaderFactory parameter (defaults to LibplctagTemplateReaderFactory) + new internal FetchUdtShapeAsync that — checks AbCipTemplateCache first, misses call the reader + decode + cache, template-read exceptions + decode failures return null so callers can fall back to declaration-driven fan-out without the whole discovery blowing up. OperationCanceledException rethrows for shutdown propagation. Unknown device host returns null without attempting a fetch. FlushOptionalCachesAsync empties the cache so a subsequent fetch re-reads. 16 new decoder tests — simple two-member UDT, struct-member flag → Structure, array member ArrayLength, 6-member mixed-type with correct offsets, unknown type code → Structure, zero member count → null, short buffer → null, missing member name → placeholder, ParseSemicolonTerminatedStrings theory across 5 shapes. 6 new AbCipFetchUdtShapeTests exercising the driver integration via reflection (method is internal) — happy-path decode + cache, different template ids get separate fetches, unknown device → null without reader creation, decode failure returns null + doesn't cache (next call retries), reader exception returns null, FlushOptionalCachesAsync clears the cache. Total AbCip unit tests now 211/211 passing (+19 from the @tags merge's 192); full solution builds 0 errors; other drivers untouched. Whole-UDT read optimization (single libplctag call returning the packed buffer + client-side member decode using the template offsets) is left as a follow-up — requires rethinking the per-tag read path + careful hardware validation; current per-member fan-out still works correctly, just with N round-trips instead of 1.
AB CIP @tags walker — CIP Symbol Object decoder + LibplctagTagEnumerator. Closes task #178. CipSymbolObjectDecoder (pure-managed, no libplctag dep) parses the raw Symbol Object (class 0x6B) blob returned by reading the @tags pseudo-tag into an enumerable sequence of AbCipDiscoveredTag records. Entry layout per Rockwell CIP Vol 1 + Logix 5000 CIP Programming Manual 1756-PM019, cross-checked against libplctag's ab/cip.c handle_listed_tags_reply — u32 instance-id + u16 symbol-type + u16 element-length + 3×u32 array-dims + u16 name-length + name[len] + even-pad. Symbol-type lower 12 bits carry the CIP type code (0xC1 BOOL, 0xC2 SINT, …, 0xD0 STRING), bit 12 is the system-tag flag, bit 15 is the struct flag (when set lower 12 bits become the template instance id). Truncated tails stop decoding gracefully — caller keeps whatever parsed cleanly rather than getting an exception mid-walk. Program:-scope names (Program:MainProgram.StepIndex) are split via SplitProgramScope so the enumerator surfaces scope + simple name separately. 12 atomic type codes mapped (BOOL/SINT/INT/DINT/LINT/USINT/UINT/UDINT/ULINT/REAL/LREAL/STRING + DT/DATE_AND_TIME under Dt); unknown codes return null so the caller treats them as opaque Structure. LibplctagTagEnumerator is the real production walker — creates a libplctag Tag with name=@tags against the device's gateway/port/path, InitializeAsync + ReadAsync + GetBuffer, hands bytes to the decoder. Factory LibplctagTagEnumeratorFactory replaces EmptyAbCipTagEnumeratorFactory as the AbCipDriver default. AbCipDriverOptions gains EnableControllerBrowse (default false) matching the TwinCAT pattern — keeps the strict-config path for deployments where only declared tags should appear. When true, DiscoverAsync walks each device's @tags + emits surviving symbols under Discovered/ sub-folder. System-tag filter (AbCipSystemTagFilter shipped in PR 5) runs alongside the wire-layer system-flag hint. Tests — 18 new CipSymbolObjectDecoderTests with crafted byte arrays matching the documented layout — single-entry DInt, theory across 12 atomic type codes, unknown→null, struct flag override, system flag surface, Program:-scope split, multi-entry wire-order with even-pad, truncated-buffer graceful stop, empty buffer, SplitProgramScope theory across 6 shapes. 4 pre-existing AbCipDriverDiscoveryTests that tested controller-enumeration behavior updated with EnableControllerBrowse=true so they continue exercising the walker path (behavior unchanged from their perspective). Total AbCip unit tests now 192/192 passing (+26 from the RMW merge's 166); full solution builds 0 errors; other drivers untouched. Field validation note — the decoder layout matches published Rockwell docs + libplctag C source, but actual @tags responses vary slightly by controller firmware (some ship an older entry format with u16 array dims instead of u32). Any layout drift surfaces as gibberish names in the Discovered/ folder; field testing will flag that for a decoder patch if it occurs.
AB CIP PR 2 — scaffolding + Core (AbCipDriver skeleton + libplctag binding + host / tag-path / data-type / status-code parsers + per-family profiles + SafeHandle wrapper + test harness). Ships everything needed to stand up the driver project as a compiling assembly with no wire calls yet — PR 3 adds IReadable against ab_server which is the first PR that actually touches the native library. Project reference shape matches Modbus / OpcUaClient / S7 (only Core.Abstractions, no Core / Configuration / Polly) so the driver stays lean and doesn't drag EF Core into every deployment that wants AB support. libplctag 1.5.2 pinned (1.6.x only exists as alpha — stable 1.5 series covers ControlLogix / CompactLogix / Micro800 / SLC500 / PLC-5 / MicroLogix which matches plan decision #11 family coverage). libplctag.NativeImport arrives transitively. AbCipHostAddress parses ab://gateway[:port]/cip-path canonical strings end-to-end: handles hostname or IP gateway, optional explicit port (default 44818 EtherNet-IP reserved), CIP path including bridged routes (1,2,2,10.0.0.10,1,0), empty path for Micro800 / MicroLogix without backplane routing, case-insensitive scheme, default-port stripping in canonical form for round-trip stability. Opaque string survives straight into libplctag's gateway / path attributes so no translation layer at wire time. AbCipTagPath handles the full Logix symbolic tag surface — controller-scope (Motor1_Speed), program-scope (Program:MainProgram.StepIndex), structured member access (Motor1.Speed.Setpoint), multi-dim array subscripts (Matrix[1,2,3]), bit-within-DINT via .N syntax (Flags.3, Motor.Status.12) with valid range 0-31 per Logix 5000 General Instructions Reference. Structural capture so PR 6 UDT work can walk the path against a cached template without reparsing. Rejects malformed shapes (empty scopes, ident starting with digit, spaces, empty/negative/non-numeric subscripts, unbalanced brackets, leading / trailing dots). Round-trips via ToLibplctagName producing the exact string libplctag's name attribute expects. AbCipDataType mirrors ModbusDataType shape — atomic Bool / SInt / Int / DInt / LInt / USInt / UInt / UDInt / ULInt / Real / LReal / String / Dt plus a Structure marker for UDT-typed tags (resolved via CIP Template Object at discovery time in PR 5/6). ToDriverDataType adapter follows the Modbus widening convention for unsigned + 64-bit until DriverDataType picks those up. AbCipStatusMapper covers the CIP general-status values an AB PLC actually returns during normal operation (0x00/0x04/0x05/0x06/0x08/0x0A/0x0B/0x0E/0x10/0x13/0x16) + libplctag PLCTAG_STATUS_* codes (0, >0 pending, negative error families). Mirrors ModbusDriver.MapModbusExceptionToStatus so Admin UI status displays stay uniform across drivers. PlcTagHandle is a SafeHandle around the int32 native tag ID with plc_tag_destroy slot wired as a no-op for PR 2 (P/Invoke DllImport arrives with PR 3 when the wire calls land). Lifetime guaranteed by the SafeHandle finalizer — every leaked handle gets cleaned up even when the owner is GC'd without explicit Dispose. IsInvalid when native ID <= 0 so destroying a negative (error) handle never happens. Critical because driver-specs.md §3 flags libplctag native heap as invisible to GetMemoryFootprint — leaked handles directly feed the Tier-B recycle trigger. AbCipDriverOptions captures the multi-device shape — one driver instance can talk to N PLCs via Devices[] (each with HostAddress + PlcFamily + optional DeviceName); Tags[] references devices by HostAddress as the cross-key; AbCipProbeOptions + driver-wide Timeout. AbCipDriver implements IDriver only — InitializeAsync parses every device's HostAddress and selects its PlcFamilyProfile (fails fast on malformed strings via InvalidOperationException → Faulted health), per-device state cached in a DeviceState record with parsed address + profile + empty TagHandles dict for later PRs. ReinitializeAsync is the Tier-B escape hatch — shuts down every device, disposes every PlcTagHandle via SafeHandle lifetime, reinitializes from options. ShutdownAsync clears the device dict and flips health to Unknown. PlcFamilies/AbCipPlcFamilyProfile gives four baseline profiles — ControlLogix (4002 ConnectionSize, path 1,0, Large Forward Open + request packing + connected messaging, FW20+ baseline), CompactLogix (narrower 504 default for 5069-L3x safety), Micro800 (488 cap, empty path, unconnected-only, no request packing), GuardLogix (shares ControlLogix wire protocol — safety partition is tag-level, surfaced as ViewOnly in PR 12). Tests — 76 new cases across 4 test classes — AbCipHostAddressTests (10 valid shapes, 10 invalid shapes, ToString canonicalization, round-trip stability), AbCipTagPathTests (18 cases including multi-scope / multi-member / multi-subscript / bit-in-DINT / rejected shapes / underscore idents / round-trip), AbCipStatusMapperTests (12 CIP + 8 libplctag codes), AbCipDriverTests (IDriver lifecycle + multi-device init + malformed-address fault + per-family profile lookup + PlcTagHandle invalid/dispose idempotency + AbCipDataType mapping). Full solution builds 0 errors; 254 warnings are pre-existing xUnit1051 CancellationToken hints outside this PR. Solution file updated to include both new projects. Unblocks PR 3 (IReadable against ab_server) which is the first PR to exercise the native library end-to-end.
AB CIP PR 4 — IWritable implementation. LibplctagTagRuntime.EncodeValue fills in the switch for every atomic Logix type the driver currently surfaces — Bool (standalone BOOL via SetInt8 0/1), SInt/USInt (SetInt8/SetUInt8), Int/UInt (SetInt16/SetUInt16), DInt/UDInt (SetInt32/SetUInt32), LInt/ULInt (SetInt64/SetUInt64), Real (SetFloat32), LReal (SetFloat64), String (SetString 0), Dt (epoch DINT via SetInt32). BOOL-within-DINT writes throw NotSupportedException with a code comment matching the Modbus BitInRegister pattern at ModbusDriver.cs line 640 — the read-modify-write logic + lock-per-DINT discipline is a follow-up PR rather than squeezing it into the initial wire plumbing. Structure writes throw NotSupportedException pointing at PR 6 when UDT support lands. AbCipDriver now implements IWritable. WriteAsync iterates writes preserving order, short-circuits on unknown reference → BadNodeIdUnknown, on non-writable tag definition → BadNotWritable, on unknown device → BadNodeIdUnknown. Happy path materialises the cached runtime via EnsureTagRuntimeAsync (shares PR 3's lazy-init path so read+write on the same tag hits one native handle), EncodeValue into the tag's buffer, WriteAsync flushes, GetStatus confirms the wire status, maps libplctag error codes via AbCipStatusMapper.MapLibplctagStatus, sets health Healthy on success. Per plan decisions #44, #45, #143 the driver does NOT auto-retry writes — that's a resilience-layer concern (Polly pipeline sitting above) keyed on the tag's WriteIdempotent flag. Exception-mapping table — OperationCanceledException rethrows (honors cancellation), NotSupportedException → BadNotSupported (bit-in-DINT, Structure, future unsupported types), FormatException → BadTypeMismatch (Convert.ToInt32 of a non-numeric string), InvalidCastException → BadTypeMismatch (caller passed an object incompatible with the conversion target), OverflowException → BadOutOfRange (value exceeds target type range, e.g. Int16 write of 1_000_000), any other Exception → BadCommunicationError (wire drop, libplctag-internal failure). Health surface updates Degraded on every non-Cancellation exception path, Healthy on success. Introduces AbCipStatusMapper.BadTypeMismatch (0x80730000). 10 new unit tests in AbCipDriverWriteTests covering — unknown ref → BadNodeIdUnknown, non-writable tag → BadNotWritable, successful DInt write encodes + flushes the value + marks WriteCount=1, BOOL-in-DINT rejected as BadNotSupported (separate ThrowingBoolBitFake mirrors LibplctagTagRuntime's runtime check), non-zero libplctag status after write mapped via AbCipStatusMapper (timeout -5 → BadTimeout), FormatException from non-numeric-string write → BadTypeMismatch (RealConvertFake exercises real Convert.ToInt32), OverflowException from Int16 write of 1_000_000 → BadOutOfRange, generic exception during write → BadCommunicationError + health Degraded, batch with mixed success+failure preserves order across four request types, cancellation propagates as OperationCanceledException. FakeAbCipTag's test-fake base class methods made virtual so override hooks work correctly through the IAbCipTagRuntime interface (new-shadow was silently falling through to the base implementation). Total AbCip unit tests now 98/98 passing; Modbus + other existing tests untouched; full solution builds 0 errors.
AB CIP PR 2 — scaffolding + Core (AbCipDriver skeleton + libplctag binding + host / tag-path / data-type / status-code parsers + per-family profiles + SafeHandle wrapper + test harness). Ships everything needed to stand up the driver project as a compiling assembly with no wire calls yet — PR 3 adds IReadable against ab_server which is the first PR that actually touches the native library. Project reference shape matches Modbus / OpcUaClient / S7 (only Core.Abstractions, no Core / Configuration / Polly) so the driver stays lean and doesn't drag EF Core into every deployment that wants AB support. libplctag 1.5.2 pinned (1.6.x only exists as alpha — stable 1.5 series covers ControlLogix / CompactLogix / Micro800 / SLC500 / PLC-5 / MicroLogix which matches plan decision #11 family coverage). libplctag.NativeImport arrives transitively. AbCipHostAddress parses ab://gateway[:port]/cip-path canonical strings end-to-end: handles hostname or IP gateway, optional explicit port (default 44818 EtherNet-IP reserved), CIP path including bridged routes (1,2,2,10.0.0.10,1,0), empty path for Micro800 / MicroLogix without backplane routing, case-insensitive scheme, default-port stripping in canonical form for round-trip stability. Opaque string survives straight into libplctag's gateway / path attributes so no translation layer at wire time. AbCipTagPath handles the full Logix symbolic tag surface — controller-scope (Motor1_Speed), program-scope (Program:MainProgram.StepIndex), structured member access (Motor1.Speed.Setpoint), multi-dim array subscripts (Matrix[1,2,3]), bit-within-DINT via .N syntax (Flags.3, Motor.Status.12) with valid range 0-31 per Logix 5000 General Instructions Reference. Structural capture so PR 6 UDT work can walk the path against a cached template without reparsing. Rejects malformed shapes (empty scopes, ident starting with digit, spaces, empty/negative/non-numeric subscripts, unbalanced brackets, leading / trailing dots). Round-trips via ToLibplctagName producing the exact string libplctag's name attribute expects. AbCipDataType mirrors ModbusDataType shape — atomic Bool / SInt / Int / DInt / LInt / USInt / UInt / UDInt / ULInt / Real / LReal / String / Dt plus a Structure marker for UDT-typed tags (resolved via CIP Template Object at discovery time in PR 5/6). ToDriverDataType adapter follows the Modbus widening convention for unsigned + 64-bit until DriverDataType picks those up. AbCipStatusMapper covers the CIP general-status values an AB PLC actually returns during normal operation (0x00/0x04/0x05/0x06/0x08/0x0A/0x0B/0x0E/0x10/0x13/0x16) + libplctag PLCTAG_STATUS_* codes (0, >0 pending, negative error families). Mirrors ModbusDriver.MapModbusExceptionToStatus so Admin UI status displays stay uniform across drivers. PlcTagHandle is a SafeHandle around the int32 native tag ID with plc_tag_destroy slot wired as a no-op for PR 2 (P/Invoke DllImport arrives with PR 3 when the wire calls land). Lifetime guaranteed by the SafeHandle finalizer — every leaked handle gets cleaned up even when the owner is GC'd without explicit Dispose. IsInvalid when native ID <= 0 so destroying a negative (error) handle never happens. Critical because driver-specs.md §3 flags libplctag native heap as invisible to GetMemoryFootprint — leaked handles directly feed the Tier-B recycle trigger. AbCipDriverOptions captures the multi-device shape — one driver instance can talk to N PLCs via Devices[] (each with HostAddress + PlcFamily + optional DeviceName); Tags[] references devices by HostAddress as the cross-key; AbCipProbeOptions + driver-wide Timeout. AbCipDriver implements IDriver only — InitializeAsync parses every device's HostAddress and selects its PlcFamilyProfile (fails fast on malformed strings via InvalidOperationException → Faulted health), per-device state cached in a DeviceState record with parsed address + profile + empty TagHandles dict for later PRs. ReinitializeAsync is the Tier-B escape hatch — shuts down every device, disposes every PlcTagHandle via SafeHandle lifetime, reinitializes from options. ShutdownAsync clears the device dict and flips health to Unknown. PlcFamilies/AbCipPlcFamilyProfile gives four baseline profiles — ControlLogix (4002 ConnectionSize, path 1,0, Large Forward Open + request packing + connected messaging, FW20+ baseline), CompactLogix (narrower 504 default for 5069-L3x safety), Micro800 (488 cap, empty path, unconnected-only, no request packing), GuardLogix (shares ControlLogix wire protocol — safety partition is tag-level, surfaced as ViewOnly in PR 12). Tests — 76 new cases across 4 test classes — AbCipHostAddressTests (10 valid shapes, 10 invalid shapes, ToString canonicalization, round-trip stability), AbCipTagPathTests (18 cases including multi-scope / multi-member / multi-subscript / bit-in-DINT / rejected shapes / underscore idents / round-trip), AbCipStatusMapperTests (12 CIP + 8 libplctag codes), AbCipDriverTests (IDriver lifecycle + multi-device init + malformed-address fault + per-family profile lookup + PlcTagHandle invalid/dispose idempotency + AbCipDataType mapping). Full solution builds 0 errors; 254 warnings are pre-existing xUnit1051 CancellationToken hints outside this PR. Solution file updated to include both new projects. Unblocks PR 3 (IReadable against ab_server) which is the first PR to exercise the native library end-to-end.
AB CIP @tags walker — CIP Symbol Object decoder + LibplctagTagEnumerator. Closes task #178. CipSymbolObjectDecoder (pure-managed, no libplctag dep) parses the raw Symbol Object (class 0x6B) blob returned by reading the @tags pseudo-tag into an enumerable sequence of AbCipDiscoveredTag records. Entry layout per Rockwell CIP Vol 1 + Logix 5000 CIP Programming Manual 1756-PM019, cross-checked against libplctag's ab/cip.c handle_listed_tags_reply — u32 instance-id + u16 symbol-type + u16 element-length + 3×u32 array-dims + u16 name-length + name[len] + even-pad. Symbol-type lower 12 bits carry the CIP type code (0xC1 BOOL, 0xC2 SINT, …, 0xD0 STRING), bit 12 is the system-tag flag, bit 15 is the struct flag (when set lower 12 bits become the template instance id). Truncated tails stop decoding gracefully — caller keeps whatever parsed cleanly rather than getting an exception mid-walk. Program:-scope names (Program:MainProgram.StepIndex) are split via SplitProgramScope so the enumerator surfaces scope + simple name separately. 12 atomic type codes mapped (BOOL/SINT/INT/DINT/LINT/USINT/UINT/UDINT/ULINT/REAL/LREAL/STRING + DT/DATE_AND_TIME under Dt); unknown codes return null so the caller treats them as opaque Structure. LibplctagTagEnumerator is the real production walker — creates a libplctag Tag with name=@tags against the device's gateway/port/path, InitializeAsync + ReadAsync + GetBuffer, hands bytes to the decoder. Factory LibplctagTagEnumeratorFactory replaces EmptyAbCipTagEnumeratorFactory as the AbCipDriver default. AbCipDriverOptions gains EnableControllerBrowse (default false) matching the TwinCAT pattern — keeps the strict-config path for deployments where only declared tags should appear. When true, DiscoverAsync walks each device's @tags + emits surviving symbols under Discovered/ sub-folder. System-tag filter (AbCipSystemTagFilter shipped in PR 5) runs alongside the wire-layer system-flag hint. Tests — 18 new CipSymbolObjectDecoderTests with crafted byte arrays matching the documented layout — single-entry DInt, theory across 12 atomic type codes, unknown→null, struct flag override, system flag surface, Program:-scope split, multi-entry wire-order with even-pad, truncated-buffer graceful stop, empty buffer, SplitProgramScope theory across 6 shapes. 4 pre-existing AbCipDriverDiscoveryTests that tested controller-enumeration behavior updated with EnableControllerBrowse=true so they continue exercising the walker path (behavior unchanged from their perspective). Total AbCip unit tests now 192/192 passing (+26 from the RMW merge's 166); full solution builds 0 errors; other drivers untouched. Field validation note — the decoder layout matches published Rockwell docs + libplctag C source, but actual @tags responses vary slightly by controller firmware (some ship an older entry format with u16 array dims instead of u32). Any layout drift surfaces as gibberish names in the Discovered/ folder; field testing will flag that for a decoder patch if it occurs.
AB CIP UDT Template Object shape reader. Closes the shape-reader half of task #179. CipTemplateObjectDecoder (pure-managed) parses the Read Template blob per Rockwell CIP Vol 1 + libplctag ab/cip.c handle_read_template_reply — 12-byte header (u16 member_count + u16 struct_handle + u32 instance_size + u32 member_def_size) followed by memberCount × 8-byte member blocks (u16 info with bit-15 struct flag + lower-12-bit type code matching the Symbol Object encoding, u16 array_size, u32 struct_offset) followed by semicolon-terminated strings (UDT name first, then one per member). ParseSemicolonTerminatedStrings handles the observed firmware variations — name;\0 vs name; delimiters, optional null/space padding after the semicolon, trailing-name-without-semicolon corner case. Struct-flag members decode as AbCipDataType.Structure; unknown atomic codes fall back to Structure so the shape remains valid even with unrecognised members. Zero member count + short buffer both return null; missing member names yield <member_N> placeholders. IAbCipTemplateReader + IAbCipTemplateReaderFactory abstraction — one call per template instance id returning the raw blob. LibplctagTemplateReader is the production implementation creating a libplctag Tag with name @udt/{templateId} + handing the buffer to the decoder. AbCipDriver ctor gains optional templateReaderFactory parameter (defaults to LibplctagTemplateReaderFactory) + new internal FetchUdtShapeAsync that — checks AbCipTemplateCache first, misses call the reader + decode + cache, template-read exceptions + decode failures return null so callers can fall back to declaration-driven fan-out without the whole discovery blowing up. OperationCanceledException rethrows for shutdown propagation. Unknown device host returns null without attempting a fetch. FlushOptionalCachesAsync empties the cache so a subsequent fetch re-reads. 16 new decoder tests — simple two-member UDT, struct-member flag → Structure, array member ArrayLength, 6-member mixed-type with correct offsets, unknown type code → Structure, zero member count → null, short buffer → null, missing member name → placeholder, ParseSemicolonTerminatedStrings theory across 5 shapes. 6 new AbCipFetchUdtShapeTests exercising the driver integration via reflection (method is internal) — happy-path decode + cache, different template ids get separate fetches, unknown device → null without reader creation, decode failure returns null + doesn't cache (next call retries), reader exception returns null, FlushOptionalCachesAsync clears the cache. Total AbCip unit tests now 211/211 passing (+19 from the @tags merge's 192); full solution builds 0 errors; other drivers untouched. Whole-UDT read optimization (single libplctag call returning the packed buffer + client-side member decode using the template offsets) is left as a follow-up — requires rethinking the per-tag read path + careful hardware validation; current per-member fan-out still works correctly, just with N round-trips instead of 1.
AB CIP UDT Template Object shape reader. Closes the shape-reader half of task #179. CipTemplateObjectDecoder (pure-managed) parses the Read Template blob per Rockwell CIP Vol 1 + libplctag ab/cip.c handle_read_template_reply — 12-byte header (u16 member_count + u16 struct_handle + u32 instance_size + u32 member_def_size) followed by memberCount × 8-byte member blocks (u16 info with bit-15 struct flag + lower-12-bit type code matching the Symbol Object encoding, u16 array_size, u32 struct_offset) followed by semicolon-terminated strings (UDT name first, then one per member). ParseSemicolonTerminatedStrings handles the observed firmware variations — name;\0 vs name; delimiters, optional null/space padding after the semicolon, trailing-name-without-semicolon corner case. Struct-flag members decode as AbCipDataType.Structure; unknown atomic codes fall back to Structure so the shape remains valid even with unrecognised members. Zero member count + short buffer both return null; missing member names yield <member_N> placeholders. IAbCipTemplateReader + IAbCipTemplateReaderFactory abstraction — one call per template instance id returning the raw blob. LibplctagTemplateReader is the production implementation creating a libplctag Tag with name @udt/{templateId} + handing the buffer to the decoder. AbCipDriver ctor gains optional templateReaderFactory parameter (defaults to LibplctagTemplateReaderFactory) + new internal FetchUdtShapeAsync that — checks AbCipTemplateCache first, misses call the reader + decode + cache, template-read exceptions + decode failures return null so callers can fall back to declaration-driven fan-out without the whole discovery blowing up. OperationCanceledException rethrows for shutdown propagation. Unknown device host returns null without attempting a fetch. FlushOptionalCachesAsync empties the cache so a subsequent fetch re-reads. 16 new decoder tests — simple two-member UDT, struct-member flag → Structure, array member ArrayLength, 6-member mixed-type with correct offsets, unknown type code → Structure, zero member count → null, short buffer → null, missing member name → placeholder, ParseSemicolonTerminatedStrings theory across 5 shapes. 6 new AbCipFetchUdtShapeTests exercising the driver integration via reflection (method is internal) — happy-path decode + cache, different template ids get separate fetches, unknown device → null without reader creation, decode failure returns null + doesn't cache (next call retries), reader exception returns null, FlushOptionalCachesAsync clears the cache. Total AbCip unit tests now 211/211 passing (+19 from the @tags merge's 192); full solution builds 0 errors; other drivers untouched. Whole-UDT read optimization (single libplctag call returning the packed buffer + client-side member decode using the template offsets) is left as a follow-up — requires rethinking the per-tag read path + careful hardware validation; current per-member fan-out still works correctly, just with N round-trips instead of 1.
AB CIP @tags walker — CIP Symbol Object decoder + LibplctagTagEnumerator. Closes task #178. CipSymbolObjectDecoder (pure-managed, no libplctag dep) parses the raw Symbol Object (class 0x6B) blob returned by reading the @tags pseudo-tag into an enumerable sequence of AbCipDiscoveredTag records. Entry layout per Rockwell CIP Vol 1 + Logix 5000 CIP Programming Manual 1756-PM019, cross-checked against libplctag's ab/cip.c handle_listed_tags_reply — u32 instance-id + u16 symbol-type + u16 element-length + 3×u32 array-dims + u16 name-length + name[len] + even-pad. Symbol-type lower 12 bits carry the CIP type code (0xC1 BOOL, 0xC2 SINT, …, 0xD0 STRING), bit 12 is the system-tag flag, bit 15 is the struct flag (when set lower 12 bits become the template instance id). Truncated tails stop decoding gracefully — caller keeps whatever parsed cleanly rather than getting an exception mid-walk. Program:-scope names (Program:MainProgram.StepIndex) are split via SplitProgramScope so the enumerator surfaces scope + simple name separately. 12 atomic type codes mapped (BOOL/SINT/INT/DINT/LINT/USINT/UINT/UDINT/ULINT/REAL/LREAL/STRING + DT/DATE_AND_TIME under Dt); unknown codes return null so the caller treats them as opaque Structure. LibplctagTagEnumerator is the real production walker — creates a libplctag Tag with name=@tags against the device's gateway/port/path, InitializeAsync + ReadAsync + GetBuffer, hands bytes to the decoder. Factory LibplctagTagEnumeratorFactory replaces EmptyAbCipTagEnumeratorFactory as the AbCipDriver default. AbCipDriverOptions gains EnableControllerBrowse (default false) matching the TwinCAT pattern — keeps the strict-config path for deployments where only declared tags should appear. When true, DiscoverAsync walks each device's @tags + emits surviving symbols under Discovered/ sub-folder. System-tag filter (AbCipSystemTagFilter shipped in PR 5) runs alongside the wire-layer system-flag hint. Tests — 18 new CipSymbolObjectDecoderTests with crafted byte arrays matching the documented layout — single-entry DInt, theory across 12 atomic type codes, unknown→null, struct flag override, system flag surface, Program:-scope split, multi-entry wire-order with even-pad, truncated-buffer graceful stop, empty buffer, SplitProgramScope theory across 6 shapes. 4 pre-existing AbCipDriverDiscoveryTests that tested controller-enumeration behavior updated with EnableControllerBrowse=true so they continue exercising the walker path (behavior unchanged from their perspective). Total AbCip unit tests now 192/192 passing (+26 from the RMW merge's 166); full solution builds 0 errors; other drivers untouched. Field validation note — the decoder layout matches published Rockwell docs + libplctag C source, but actual @tags responses vary slightly by controller firmware (some ship an older entry format with u16 array dims instead of u32). Any layout drift surfaces as gibberish names in the Discovered/ folder; field testing will flag that for a decoder patch if it occurs.
RMW pass 2 — AbCip BOOL-within-DINT + AbLegacy bit-within-word. Closes task #181. AbCip — AbCipDriver.WriteAsync now detects BOOL writes with a bit index + routes them through WriteBitInDIntAsync: strip the .N suffix to form the parent DINT tag path (via AbCipTagPath with BitIndex=null + ToLibplctagName), get/create a cached parent IAbCipTagRuntime via EnsureParentRuntimeAsync (distinct from the bit-selector tag runtime so read + write target the DINT directly), acquire a per-parent-name SemaphoreSlim, Read → Convert.ToInt32 the current DINT → (current | 1<<bit) or (current & ~(1<<bit)) → Write via EncodeValue(DInt, updated). Per-parent lock prevents concurrent writers to the same DINT from losing updates — parallels Modbus + FOCAS pass 1. DeviceState gains ParentRuntimes dict + GetRmwLock helper + _rmwLocks ConcurrentDictionary. DisposeHandles now walks ParentRuntimes too. LibplctagTagRuntime.EncodeValue's BOOL-with-bitIndex branch stays as a defensive throw (message updated to point at the new driver-level dispatch) so an accidental bypass fails loudly rather than silently clobbering the whole DINT. AbLegacy — identical pattern for PCCC N-file bit writes. AbLegacyDriver.WriteAsync detects Bit with bitIndex + PMC letter not in {B, I, O} (B-file + I/O use their own bit-addressable semantics so don't RMW at N-file word level), routes through WriteBitInWordAsync which uses Int16 for the parent word, creates + caches a parent runtime with the suffix-stripped N7:0 address, acquires per-parent lock, RMW. DeviceState extended the same way as AbCip (ParentRuntimes + GetRmwLock). LibplctagLegacyTagRuntime.EncodeValue Bit-with-bitIndex branch points at the driver dispatch. Tests — 5 new AbCipBoolInDIntRmwTests (bit set ORs + preserves, bit clear ANDs + preserves, 8-way concurrent writes to same parent compose to 0xFF, different-parent writes get separate runtimes, repeat bit writes reuse the parent runtime init-count 1 + write-count 2), 4 new AbLegacyBitRmwTests (bit set preserves, bit clear preserves 0xFFF7, 8-way concurrent 0xFF, repeat writes reuse parent). Two pre-existing tests flipped — AbCipDriverWriteTests.Bit_in_dint_write_returns_BadNotSupported + AbLegacyReadWriteTests.Bit_within_word_write_rejected_as_BadNotSupported both now assert Good instead of BadNotSupported, renamed to _now_succeeds_via_RMW. Total tests — AbCip 166/166, AbLegacy 96/96, full solution builds 0 errors; Modbus + FOCAS + TwinCAT + other drivers untouched. Task #181 done across all four libplctag-backed + non-libplctag drivers (Modbus BitInRegister + AbCip BOOL-in-DINT + AbLegacy N-file bit + FOCAS PMC Bit — all with per-parent-word serialisation).
AB CIP UDT Template Object shape reader. Closes the shape-reader half of task #179. CipTemplateObjectDecoder (pure-managed) parses the Read Template blob per Rockwell CIP Vol 1 + libplctag ab/cip.c handle_read_template_reply — 12-byte header (u16 member_count + u16 struct_handle + u32 instance_size + u32 member_def_size) followed by memberCount × 8-byte member blocks (u16 info with bit-15 struct flag + lower-12-bit type code matching the Symbol Object encoding, u16 array_size, u32 struct_offset) followed by semicolon-terminated strings (UDT name first, then one per member). ParseSemicolonTerminatedStrings handles the observed firmware variations — name;\0 vs name; delimiters, optional null/space padding after the semicolon, trailing-name-without-semicolon corner case. Struct-flag members decode as AbCipDataType.Structure; unknown atomic codes fall back to Structure so the shape remains valid even with unrecognised members. Zero member count + short buffer both return null; missing member names yield <member_N> placeholders. IAbCipTemplateReader + IAbCipTemplateReaderFactory abstraction — one call per template instance id returning the raw blob. LibplctagTemplateReader is the production implementation creating a libplctag Tag with name @udt/{templateId} + handing the buffer to the decoder. AbCipDriver ctor gains optional templateReaderFactory parameter (defaults to LibplctagTemplateReaderFactory) + new internal FetchUdtShapeAsync that — checks AbCipTemplateCache first, misses call the reader + decode + cache, template-read exceptions + decode failures return null so callers can fall back to declaration-driven fan-out without the whole discovery blowing up. OperationCanceledException rethrows for shutdown propagation. Unknown device host returns null without attempting a fetch. FlushOptionalCachesAsync empties the cache so a subsequent fetch re-reads. 16 new decoder tests — simple two-member UDT, struct-member flag → Structure, array member ArrayLength, 6-member mixed-type with correct offsets, unknown type code → Structure, zero member count → null, short buffer → null, missing member name → placeholder, ParseSemicolonTerminatedStrings theory across 5 shapes. 6 new AbCipFetchUdtShapeTests exercising the driver integration via reflection (method is internal) — happy-path decode + cache, different template ids get separate fetches, unknown device → null without reader creation, decode failure returns null + doesn't cache (next call retries), reader exception returns null, FlushOptionalCachesAsync clears the cache. Total AbCip unit tests now 211/211 passing (+19 from the @tags merge's 192); full solution builds 0 errors; other drivers untouched. Whole-UDT read optimization (single libplctag call returning the packed buffer + client-side member decode using the template offsets) is left as a follow-up — requires rethinking the per-tag read path + careful hardware validation; current per-member fan-out still works correctly, just with N round-trips instead of 1.
AB CIP PR 2 — scaffolding + Core (AbCipDriver skeleton + libplctag binding + host / tag-path / data-type / status-code parsers + per-family profiles + SafeHandle wrapper + test harness). Ships everything needed to stand up the driver project as a compiling assembly with no wire calls yet — PR 3 adds IReadable against ab_server which is the first PR that actually touches the native library. Project reference shape matches Modbus / OpcUaClient / S7 (only Core.Abstractions, no Core / Configuration / Polly) so the driver stays lean and doesn't drag EF Core into every deployment that wants AB support. libplctag 1.5.2 pinned (1.6.x only exists as alpha — stable 1.5 series covers ControlLogix / CompactLogix / Micro800 / SLC500 / PLC-5 / MicroLogix which matches plan decision #11 family coverage). libplctag.NativeImport arrives transitively. AbCipHostAddress parses ab://gateway[:port]/cip-path canonical strings end-to-end: handles hostname or IP gateway, optional explicit port (default 44818 EtherNet-IP reserved), CIP path including bridged routes (1,2,2,10.0.0.10,1,0), empty path for Micro800 / MicroLogix without backplane routing, case-insensitive scheme, default-port stripping in canonical form for round-trip stability. Opaque string survives straight into libplctag's gateway / path attributes so no translation layer at wire time. AbCipTagPath handles the full Logix symbolic tag surface — controller-scope (Motor1_Speed), program-scope (Program:MainProgram.StepIndex), structured member access (Motor1.Speed.Setpoint), multi-dim array subscripts (Matrix[1,2,3]), bit-within-DINT via .N syntax (Flags.3, Motor.Status.12) with valid range 0-31 per Logix 5000 General Instructions Reference. Structural capture so PR 6 UDT work can walk the path against a cached template without reparsing. Rejects malformed shapes (empty scopes, ident starting with digit, spaces, empty/negative/non-numeric subscripts, unbalanced brackets, leading / trailing dots). Round-trips via ToLibplctagName producing the exact string libplctag's name attribute expects. AbCipDataType mirrors ModbusDataType shape — atomic Bool / SInt / Int / DInt / LInt / USInt / UInt / UDInt / ULInt / Real / LReal / String / Dt plus a Structure marker for UDT-typed tags (resolved via CIP Template Object at discovery time in PR 5/6). ToDriverDataType adapter follows the Modbus widening convention for unsigned + 64-bit until DriverDataType picks those up. AbCipStatusMapper covers the CIP general-status values an AB PLC actually returns during normal operation (0x00/0x04/0x05/0x06/0x08/0x0A/0x0B/0x0E/0x10/0x13/0x16) + libplctag PLCTAG_STATUS_* codes (0, >0 pending, negative error families). Mirrors ModbusDriver.MapModbusExceptionToStatus so Admin UI status displays stay uniform across drivers. PlcTagHandle is a SafeHandle around the int32 native tag ID with plc_tag_destroy slot wired as a no-op for PR 2 (P/Invoke DllImport arrives with PR 3 when the wire calls land). Lifetime guaranteed by the SafeHandle finalizer — every leaked handle gets cleaned up even when the owner is GC'd without explicit Dispose. IsInvalid when native ID <= 0 so destroying a negative (error) handle never happens. Critical because driver-specs.md §3 flags libplctag native heap as invisible to GetMemoryFootprint — leaked handles directly feed the Tier-B recycle trigger. AbCipDriverOptions captures the multi-device shape — one driver instance can talk to N PLCs via Devices[] (each with HostAddress + PlcFamily + optional DeviceName); Tags[] references devices by HostAddress as the cross-key; AbCipProbeOptions + driver-wide Timeout. AbCipDriver implements IDriver only — InitializeAsync parses every device's HostAddress and selects its PlcFamilyProfile (fails fast on malformed strings via InvalidOperationException → Faulted health), per-device state cached in a DeviceState record with parsed address + profile + empty TagHandles dict for later PRs. ReinitializeAsync is the Tier-B escape hatch — shuts down every device, disposes every PlcTagHandle via SafeHandle lifetime, reinitializes from options. ShutdownAsync clears the device dict and flips health to Unknown. PlcFamilies/AbCipPlcFamilyProfile gives four baseline profiles — ControlLogix (4002 ConnectionSize, path 1,0, Large Forward Open + request packing + connected messaging, FW20+ baseline), CompactLogix (narrower 504 default for 5069-L3x safety), Micro800 (488 cap, empty path, unconnected-only, no request packing), GuardLogix (shares ControlLogix wire protocol — safety partition is tag-level, surfaced as ViewOnly in PR 12). Tests — 76 new cases across 4 test classes — AbCipHostAddressTests (10 valid shapes, 10 invalid shapes, ToString canonicalization, round-trip stability), AbCipTagPathTests (18 cases including multi-scope / multi-member / multi-subscript / bit-in-DINT / rejected shapes / underscore idents / round-trip), AbCipStatusMapperTests (12 CIP + 8 libplctag codes), AbCipDriverTests (IDriver lifecycle + multi-device init + malformed-address fault + per-family profile lookup + PlcTagHandle invalid/dispose idempotency + AbCipDataType mapping). Full solution builds 0 errors; 254 warnings are pre-existing xUnit1051 CancellationToken hints outside this PR. Solution file updated to include both new projects. Unblocks PR 3 (IReadable against ab_server) which is the first PR to exercise the native library end-to-end.
AB CIP PR 2 — scaffolding + Core (AbCipDriver skeleton + libplctag binding + host / tag-path / data-type / status-code parsers + per-family profiles + SafeHandle wrapper + test harness). Ships everything needed to stand up the driver project as a compiling assembly with no wire calls yet — PR 3 adds IReadable against ab_server which is the first PR that actually touches the native library. Project reference shape matches Modbus / OpcUaClient / S7 (only Core.Abstractions, no Core / Configuration / Polly) so the driver stays lean and doesn't drag EF Core into every deployment that wants AB support. libplctag 1.5.2 pinned (1.6.x only exists as alpha — stable 1.5 series covers ControlLogix / CompactLogix / Micro800 / SLC500 / PLC-5 / MicroLogix which matches plan decision #11 family coverage). libplctag.NativeImport arrives transitively. AbCipHostAddress parses ab://gateway[:port]/cip-path canonical strings end-to-end: handles hostname or IP gateway, optional explicit port (default 44818 EtherNet-IP reserved), CIP path including bridged routes (1,2,2,10.0.0.10,1,0), empty path for Micro800 / MicroLogix without backplane routing, case-insensitive scheme, default-port stripping in canonical form for round-trip stability. Opaque string survives straight into libplctag's gateway / path attributes so no translation layer at wire time. AbCipTagPath handles the full Logix symbolic tag surface — controller-scope (Motor1_Speed), program-scope (Program:MainProgram.StepIndex), structured member access (Motor1.Speed.Setpoint), multi-dim array subscripts (Matrix[1,2,3]), bit-within-DINT via .N syntax (Flags.3, Motor.Status.12) with valid range 0-31 per Logix 5000 General Instructions Reference. Structural capture so PR 6 UDT work can walk the path against a cached template without reparsing. Rejects malformed shapes (empty scopes, ident starting with digit, spaces, empty/negative/non-numeric subscripts, unbalanced brackets, leading / trailing dots). Round-trips via ToLibplctagName producing the exact string libplctag's name attribute expects. AbCipDataType mirrors ModbusDataType shape — atomic Bool / SInt / Int / DInt / LInt / USInt / UInt / UDInt / ULInt / Real / LReal / String / Dt plus a Structure marker for UDT-typed tags (resolved via CIP Template Object at discovery time in PR 5/6). ToDriverDataType adapter follows the Modbus widening convention for unsigned + 64-bit until DriverDataType picks those up. AbCipStatusMapper covers the CIP general-status values an AB PLC actually returns during normal operation (0x00/0x04/0x05/0x06/0x08/0x0A/0x0B/0x0E/0x10/0x13/0x16) + libplctag PLCTAG_STATUS_* codes (0, >0 pending, negative error families). Mirrors ModbusDriver.MapModbusExceptionToStatus so Admin UI status displays stay uniform across drivers. PlcTagHandle is a SafeHandle around the int32 native tag ID with plc_tag_destroy slot wired as a no-op for PR 2 (P/Invoke DllImport arrives with PR 3 when the wire calls land). Lifetime guaranteed by the SafeHandle finalizer — every leaked handle gets cleaned up even when the owner is GC'd without explicit Dispose. IsInvalid when native ID <= 0 so destroying a negative (error) handle never happens. Critical because driver-specs.md §3 flags libplctag native heap as invisible to GetMemoryFootprint — leaked handles directly feed the Tier-B recycle trigger. AbCipDriverOptions captures the multi-device shape — one driver instance can talk to N PLCs via Devices[] (each with HostAddress + PlcFamily + optional DeviceName); Tags[] references devices by HostAddress as the cross-key; AbCipProbeOptions + driver-wide Timeout. AbCipDriver implements IDriver only — InitializeAsync parses every device's HostAddress and selects its PlcFamilyProfile (fails fast on malformed strings via InvalidOperationException → Faulted health), per-device state cached in a DeviceState record with parsed address + profile + empty TagHandles dict for later PRs. ReinitializeAsync is the Tier-B escape hatch — shuts down every device, disposes every PlcTagHandle via SafeHandle lifetime, reinitializes from options. ShutdownAsync clears the device dict and flips health to Unknown. PlcFamilies/AbCipPlcFamilyProfile gives four baseline profiles — ControlLogix (4002 ConnectionSize, path 1,0, Large Forward Open + request packing + connected messaging, FW20+ baseline), CompactLogix (narrower 504 default for 5069-L3x safety), Micro800 (488 cap, empty path, unconnected-only, no request packing), GuardLogix (shares ControlLogix wire protocol — safety partition is tag-level, surfaced as ViewOnly in PR 12). Tests — 76 new cases across 4 test classes — AbCipHostAddressTests (10 valid shapes, 10 invalid shapes, ToString canonicalization, round-trip stability), AbCipTagPathTests (18 cases including multi-scope / multi-member / multi-subscript / bit-in-DINT / rejected shapes / underscore idents / round-trip), AbCipStatusMapperTests (12 CIP + 8 libplctag codes), AbCipDriverTests (IDriver lifecycle + multi-device init + malformed-address fault + per-family profile lookup + PlcTagHandle invalid/dispose idempotency + AbCipDataType mapping). Full solution builds 0 errors; 254 warnings are pre-existing xUnit1051 CancellationToken hints outside this PR. Solution file updated to include both new projects. Unblocks PR 3 (IReadable against ab_server) which is the first PR to exercise the native library end-to-end.