First real FOCAS hardware contact (Makino Pro 5 / 31i-B @ 10.201.31.5). A full
v3 data-PDU capture corrected the initial diagnosis: the v3 block envelope is
identical to v1, so only specific payload structs / request math / one client
robustness gap were wrong — not "framing rewrites".
Fixes (all re-validated live through the fixed driver):
- version gate: accept inbound PDU {1,3}, keep emitting v1 (FocasWireProtocol).
- cnc_rdtimer: 8-byte {minute,msec} payload is little-endian (ParseTimer) — the
only decode with an in-range msec field.
- pmc_rdpmcrng: request range widened to the data-type byte width
(end = start + width - 1) so a Word/Long isn't truncated to 0 values
(was spurious BadOutOfRange); decode extracted to ParsePmcRange.
- cnc_rdsvmeter: per-axis LOADELM is 8 bytes (not 12) and names come from the
0x0089 block — ParseServoMeters fixes the misaligned 655360 garbage. Also the
"hang" was NetworkStream.ReadAsync not aborting a stalled socket: ReadExactlyAsync
now disposes the stream on cancellation so a stalled peer can't wedge a poll loop.
- cnc_rddynamic2: contract guard rejecting axis < 1 (driver poll already 1-based).
- FocasDriverProbe: run a real wire session (initiate + cnc_statinfo) instead of
degrading to Ok=true "TCP reachability only" when FWLIB is absent — a bare TCP
listener no longer reports HEALTHY.
cnc_rdparam (0x000e) is unsupported on this control — EW_FUNC across 14
request-framing variants x 4 known-present params; needs a reference FWLIB trace
or is restricted. Deferred (deployed config uses macros, not parameters).
Tests: FOCAS suite 234 green (+16), full solution builds 0 errors. Raw v3
captures checked in under tests/.../Fixtures/v3/. Capture tools under scripts/focas/.
Docs: docs/plans/2026-06-25-focas-pdu-v3-{30i-b-support,implementation-plan}.md,
docs/drivers/FOCAS.md, docs/v2/focas-version-matrix.md,
docs/deployments/wonder-app-vd03-makino-z-34184.md.
Joseph Doherty
5f0a52864c