TwinCAT PR 3 � Discovery + Subscribe + Probe + HostResolver #122

Merged
dohertj2 merged 1 commits from twincat-pr3-remaining-capabilities into v2 2026-04-19 18:38:46 -04:00

1 Commits

Author SHA1 Message Date
Joseph Doherty
aeb28cc8e7 TwinCAT PR 3 — ITagDiscovery + ISubscribable + IHostConnectivityProbe + IPerCallHostResolver. Completes the TwinCAT driver — 7-interface capability set matching AbCip / AbLegacy (minus IAlarmSource, same deferral). ITagDiscovery emits pre-declared tags under TwinCAT/device-host folder with DeviceName fallback to HostAddress; Writable→Operate / non-writable→ViewOnly. Symbol-browsing via AdsClient.ReadSymbolsAsync / ReadSymbolInfoAsync deferred to a follow-up (same shape as the @tags deferral for AbCip — needs careful traversal of the TwinCAT symbol table + type graph which the ReadSymbolsAsync API does expose but adds enough scope to warrant its own PR). ISubscribable consumes the shared PollGroupEngine — 4th consumer after Modbus + AbCip + AbLegacy. TwinCAT supports native ADS notifications (AddDeviceNotification) which would be strictly superior to polling, but plumbing through OPC UA semantics + the PollGroupEngine abstraction would require a parallel sampling path; poll-first matches the cross-driver pattern + gets the driver shippable. Follow-up task for native-notification upgrade tracked after merge. IHostConnectivityProbe — per-device probe loop using ITwinCATClient.ProbeAsync which wraps AdsClient.ReadStateAsync (cheap handshake that returns the target's AdsState, succeeds when router + target both respond). Success transitions to Running, any exception or probe-false to Stopped. Same lazy-connect + dispose-on-failure pattern as the read/write path — device state reconnects cleanly after a transient. IPerCallHostResolver maps tag full-ref to DeviceHostAddress for Phase 6.1 (DriverInstanceId, ResolvedHostName) bulkhead/breaker keying per plan decision #144; unknown refs fall back to first device, no devices → DriverInstanceId. ShutdownAsync disposes PollGroupEngine + cancels/disposes every probe CTS + disposes every cached client. DeviceState extended with ProbeLock / HostState / HostStateChangedUtc / ProbeCts matching AbCip/AbLegacy shape. 10 new tests in TwinCATCapabilityTests — discovery tag emission with correct SecurityClassification, subscription initial poll raises OnDataChange, shutdown cancels subscriptions, GetHostStatuses entry-per-device, probe Running transition on ProbeResult=true, probe Stopped on ProbeResult=false, probe disabled when Enabled=false, ResolveHost for known/unknown/no-devices paths. Total TwinCAT unit tests now 85/85 passing (+10 from PR 2's 75); full solution builds 0 errors; other drivers untouched. TwinCAT driver complete end-to-end — any TC2/TC3 AMS target reachable through a router is now shippable with read/write/discover/subscribe/probe/host-resolve, feature-parity with AbCip/AbLegacy.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-19 18:36:55 -04:00