Files
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 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 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 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.