Files
FOCAS Tier-C PR C — IPC path end-to-end: Proxy IpcFocasClient + Host FwlibFrameHandler + IFocasBackend abstraction. Third of 5 PRs for #220. Ships the wire path from IFocasClient calls in the .NET 10 driver, over a named-pipe (or in-memory stream) to the .NET 4.8 Host's FwlibFrameHandler, dispatched to an IFocasBackend. Keeps the existing IFocasClient DI seam intact so existing unit tests are unaffected (172/172 still pass). Proxy side adds Ipc/FocasIpcClient (owns one pipe stream + call gate so concurrent callers don't interleave frames, supports both real NamedPipeClientStream and arbitrary Stream for in-memory test loopback) and Ipc/IpcFocasClient (implements IFocasClient by forwarding every call as an IPC frame — Connect sends OpenSessionRequest and caches the SessionId; Read sends ReadRequest and decodes the typed value via FocasDataTypeCode; Write sends WriteRequest for non-bit data or PmcBitWriteRequest when it's a PMC bit so the RMW critical section stays on the Host; Probe sends ProbeRequest; Dispose best-effort sends CloseSessionRequest); plus FocasIpcException surfacing Host-side ErrorResponse frames as typed exceptions. Host side adds Backend/IFocasBackend (the Host's view of one FOCAS session — Open/Close/Read/Write/PmcBitWrite/Probe) with two implementations: FakeFocasBackend (in-memory, per-address value store, honors bit-write RMW semantics against the containing byte — used by tests and as an OTOPCUA_FOCAS_BACKEND=fake operational stub) and UnconfiguredFocasBackend (structured failure pointing at docs/v2/focas-deployment.md — the safe default when OTOPCUA_FOCAS_BACKEND is unset or hardware isn't configured). Ipc/FwlibFrameHandler replaces StubFrameHandler: deserializes each request DTO, delegates to the IFocasBackend, re-serializes into the matching response kind. Catches backend exceptions and surfaces them as ErrorResponse{backend-exception} rather than tearing down the pipe. Program.cs now picks the backend from OTOPCUA_FOCAS_BACKEND env var (fake/unconfigured/fwlib32; fwlib32 still maps to Unconfigured because the real Fwlib32 P/Invoke integration is a hardware-dependent follow-up — #220 captures it). Tests: 7 new IPC round-trip tests on the Proxy side (IpcFocasClient vs. an IpcLoopback fake server: connect happy path, connect rejection, read decode, write round-trip, PMC bit write routes to first-class RMW frame, probe, ErrorResponse surfaces as typed exception) + 6 new Host-side tests on FwlibFrameHandler (OpenSession allocates id, read-without-session fails, full open/write/read round-trip preserves value, PmcBitWrite sets the specified bit, Probe reports healthy with open session, UnconfiguredBackend returns pointed-at-docs error with ErrorCode=NoFwlibBackend). Existing 165 FOCAS unit tests + 24 Shared tests + 3 Host handshake tests all unchanged. Total post-PR: 172+24+9 = 205 FOCAS-family tests green. What's NOT in this PR: the actual Fwlib32.dll P/Invoke integration inside the Host (FwlibHostedBackend) lands as a hardware-dependent follow-up since no CNC is available for validation; supervisor + respawn + crash-loop breaker comes in PR D; MMF + NSSM install scripts in PR E.
FOCAS Tier-C PR E — ops glue: ProcessHostLauncher + post-mortem MMF + NSSM install scripts + doc close-out. Final of the 5 PRs for #220. With this landing, the Tier-C architecture is fully shipped; the only remaining FOCAS work is the hardware-dependent FwlibHostedBackend (real Fwlib32.dll P/Invoke, gated on #222 lab rig).
FOCAS version-matrix stabilization (PR 1 of #220 split) — ship the cheap half of the hardware-free stability gap ahead of the Tier-C out-of-process split. Without any CNC or simulator on the bench, the highest-leverage move is to catch operator config errors at init time instead of at steady-state per-read. Adds FocasCncSeries enum (Unknown/16i/0i-D/0i-F family/30i family/PowerMotion-i) + FocasCapabilityMatrix static class that encodes the per-series documented ranges for macro variables (cnc_rdmacro/wrmacro), parameters (cnc_rdparam/wrparam), and PMC letters + byte ceilings (pmc_rdpmcrng/wrpmcrng) straight from the Fanuc FOCAS Developer Kit. FocasDeviceOptions gains a Series knob (defaults Unknown = permissive so pre-matrix configs don't break on upgrade). FocasDriver.InitializeAsync now calls FocasAddress.TryParse on every tag + runs FocasCapabilityMatrix.Validate against the owning device's declared series, throwing InvalidOperationException with a reason string that names both the series and the documented limit ("Parameter #30000 is outside the documented range [0, 29999] for Thirty_i") so an operator can tell whether the mismatch is in the config or in their declared CNC model. Unknown series skips validation entirely. Ships 46 new theory cases in FocasCapabilityMatrixTests.cs — covering every boundary in the matrix (widen 16i->0i-F: macro ceiling 999->9999, param 9999->14999; widen 0i-F->30i: PMC letters +K+T; PMC-number 16i=999/0i-D=1999/0i-F=9999/30i=59999), permissive Unknown-series behavior, rejection-message content, and case-insensitive PMC-letter matching. Widening a range without updating docs/v2/focas-version-matrix.md fails a test because every InlineData cites the row it reflects. Full FOCAS test suite stays at 165/165 passing (119 existing + 46 new). Also authors docs/v2/focas-version-matrix.md as the authoritative range reference with per-function citations, CNC-series era context, error-surface shape, and the link back to the matrix code; docs/v2/implementation/focas-isolation-plan.md as the multi-PR plan for #220 Tier-C isolation (Shared contracts -> Host skeleton -> move Fwlib32 calls -> Supervisor+respawn -> MMF+ops glue, 2200-3200 LOC across 5 PRs mirroring the Galaxy Tier-C topology); and promotes docs/drivers/FOCAS-Test-Fixture.md from "version-matrix coverage = no" to explicit coverage via the new test file + cross-links to the matrix and isolation-plan docs. Leaves task #220 open since isolation itself (the expensive half) is still ahead.