ARStack M3.H.2 RC1 — Windows Engineering Preview (not stable)

ARStack Process Bus Simulator M3.H.2 RC1 — Public Engineering Preview

25 October 2026 — prerelease, NOT Public Stable. This release candidate is intended for isolated, non-production IEC 61850 SV/PTP laboratory experiments. The latest tested stable M3.H.1 continues to be processbus-sim-m3h1-20261024, without any changed assets or firmware.

What's improved

• Current-session SV STOP alarm: board-retained SVLIFE stop_cause=RUNTIME_FAULT history no longer generates a frightening error on ordinary Studio startup. A red unexpected-STOP alarm requires an observed transition from verified RUNNING to STOPPED during the current session. New fault evidence remains diagnosable.
• Compact hardware status LED: DISCONNECTED (grey), CONNECTING (blue), PREPARING (amber), READY/RUNNING (green) and ERROR (red), sourced from the active serial/identity/supervisor state.
• Canonical SV TX diagnostics: first/last ESP-IDF Ethernet transmit errors, link evidence and contiguous-burst/stop history are retained across operator restart. The fail-closed 400 consecutive TX failure threshold has not been bypassed.
• Exact Windows GUI and ESP32-P4 firmware pairing is verified in the source-head CI and installer lifecycle tests.

Exactly which binaries

Evidence	Immutable source
Studio + paired firmware source	PR #328 reviewed head fb81c247fb24cd6b5ac6aad6b3fb27486d620b96
Windows setup + portable build	GitHub Actions run 40145602361, artifact arstack-studio-native-preview-win-x64-328-fb81c247fb24cd6b5ac6aad6b3fb27486d620b96
Firmware built from same head	Run 40145602361, firmware sourceCommit=fb81c247fb24cd6b5ac6aad6b3fb27486d620b96
PR CI	10 success, 1 conditional skip, 0 failures; Windows native, Qt headless/HiDPI, firmware, cleanup and installer migration
Merge to main	c8d351f1fe80ca4cf8f3e58cf6727566bec7d1f6 (packaged runtime is PR head above; subsequent changes are release paperwork)

Download the Windows Setup or Portable ZIP, confirm the included SHA256SUMS.txt, and use the firmware bundled with that package. Do not mix preview and old stable firmware. The executable still reports the internal 0.1.1-preview engineering version; M3.H.2 RC1 is the package/release-candidate label, not a claim of a new stable semantic version or hardware-certified product.

The separate Linux pull-request AppImage artifact was a GUI/test build and did not include a cross-platform release-tag-matched firmware package. It is not promoted as a firmware-paired Linux release in RC1. Public Stable M3.H.1 remains the Linux choice.

Actual user-observed result

Two operator screenshots on COM15 show: connected idle READY, active RUNNING, and a displayed snapshot of approximately 3,999 fps, MISSED 0, TX FAIL 0. These prove useful operator-state UX and that a board claims RUNNING at that moment. They do not establish a 1-hour endurance pass, independent NIC capture, reception by DigSubAnalyzer/ARSAS, authenticated PTP grandmaster synchronization, or error-free long-term Ethernet transmission.

Stable promotion — blocked until these are completed

• Physical 3600 s retained run on this exact candidate, complete start/stop cycling and no missed frames/transport faults; attach test conditions and trustworthy raw logs.
• Recipient NIC unfiltered PCAPNG captures actual 0x88BA packets, VLAN/tag state, APPID, svID and sample-counter continuity; note NIC/offload/switch topology.
• DigSubAnalyzer receives and decodes the live stream with values and sample counter.
• ARSAS receives and decodes the same real stream independently, with filters/NIC identity recorded.
• Verify full package SHA-256, firmware manifest/source pairing, installer migration and Windows/Linux cross-platform distribution for the new stable release tag. Do not relabel these preview binaries stable.
• Activate and independently verify main branch protection under authorized repository administration before calling governance complete.

Field incident: #324. Release gate/runbook: independent SV wire capture and RC2 physical acceptance.

This candidate is strictly prerelease=true. The workflow refuses to overwrite or downgrade the existing Public Stable release, and its artifacts are pinned and checksum-checked before publication.