AbCip IAlarmSource via ALMD projection (#177, feature-flagged) #159

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dohertj2 merged 1 commits from abcip-alarm-source into v2 2026-04-20 04:26:40 -04:00

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Author SHA1 Message Date
Joseph Doherty
4e80db4844 AbCip IAlarmSource via ALMD projection (#177) — feature-flagged OFF by default; when enabled, polls declared ALMD UDT member fields + raises OnAlarmEvent on 0→1 + 1→0 transitions. Closes task #177. The AB CIP driver now implements IAlarmSource so the generic-driver alarm dispatch path (PR 14's sinks + the Server.Security.AuthorizationGate AlarmSubscribe/AlarmAck invoker wrapping) can treat AB-backed alarms uniformly with Galaxy + OpcUaClient + FOCAS. Projection is ALMD-only in this pass: the Logix ALMD (digital alarm) instruction's UDT shape is well-understood (InFaulted + Acked + Severity + In + Cfg_ProgTime at stable member names) so the polled-read + state-diff pattern fits without concessions. ALMA (analog alarm) deferred to a follow-up because its HHLimit/HLimit/LLimit/LLLimit threshold + In value semantics deserve their own design pass — raising on threshold-crossing is not the same shape as raising on InFaulted-edge. AbCipDriverOptions gains two knobs: EnableAlarmProjection (default false) + AlarmPollInterval (default 1s). Explicit opt-in because projection semantics don't exactly mirror Rockwell FT Alarm & Events; shops running FT Live should leave this off + take alarms through the native A&E route. AbCipAlarmProjection is the state machine: per-subscription background loop polls the source-node set via the driver's public ReadAsync — which gains the #194 whole-UDT optimization for free when ALMDs are declared with their standard member set, so one poll tick reads (N alarms × 2 members) = N libplctag round-trips rather than 2N. Per-tick state diff: compare InFaulted + Severity against last-seen, fire raise (0→1) / clear (1→0) with AlarmSeverity bucketed via the 1-1000 Logix severity scale (≤250 Low, ≤500 Medium, ≤750 High, rest Critical — matches OpcUaClient's MapSeverity shape). ConditionId is {sourceNode}#active — matches a single active-branch per alarm which is all ALMD supports; when Cfg_ProgTime-based branch identity becomes interesting (re-raise after ack with new timestamp), a richer ConditionId pass can land. Subscribe-while-disabled returns a handle wrapping id=0 — capability negotiation (the server queries IAlarmSource presence at driver-load time) still succeeds, the alarm surface just never fires. Unsubscribe cancels the sub's CTS + awaits its loop; ShutdownAsync cancels every sub on its way out so a driver reload doesn't leak poll tasks. AcknowledgeAsync routes through the driver's existing WriteAsync path — per-ack writes {SourceNodeId}.Acked = true (the simpler semantic; operators whose ladder watches AckCmd + rising-edge can wire a client-side pulse until a driver-level edge-mode knob lands). Best-effort — per-ack faults are swallowed so one bad ack doesn't poison the whole batch. Six new AbCipAlarmProjectionTests: detector flags ALMD signature + skips non-signature UDTs + atomics; severity mapping matches OPC UA A&C bucket boundaries; feature-flag OFF returns a handle but never touches the fake runtime (proving no background polling happens); feature-flag ON fires a raise event on 0→1; clear event fires on 1→0 after a prior raise; unsubscribe stops the poll loop (ReadCount doesn't grow past cancel + at most one straggler read). Driver builds 0 errors; AbCip.Tests 233/233 (was 227, +6 new). Task #177 closed — the last pending AB CIP follow-up is now #194 (already shipped). Remaining pending fleet-wide: #150 (Galaxy MXAccess failover hardware) + #199 (UnsTab Playwright smoke).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-20 04:24:40 -04:00