From 0659543a156edb8b114284b702202c97e05be0eb Mon Sep 17 00:00:00 2001 From: serversdown Date: Fri, 25 Sep 2026 23:27:21 -0400 Subject: [PATCH] docs(series4): the 2026-09-22 failure is accounted for -- the timeline was wrong An earlier draft said the Prolific-cable finding did not fit the timeline, since the unit was described as working and then degrading, which a cable that never enumerates cannot do. The timeline was what needed correcting. From the operator: the initial setup was ONE modem and ONE cable, and it worked. Two Micromates then had to be deployed, so a second cable was fetched to run both at once -- and only one of the two ever worked. The other never talked over its modem at any point, was never deployed, and a MiniMate Plus went out in its place. That Micromate came back to the bench, and the cable on it is a Benfei (Prolific PL2303). So nothing degraded. The "worked at first" was the single-cable setup before the split. One unit working and one not, configured side by side, is the signature of a mixed cable supply rather than a unit fault. Still worth confirming whether that cable travelled home with the unit or was picked up at the bench; if it travelled with it there is no inference left. The FTDI cable arriving 2026-09-26 settles it either way -- same unit, same modem, one variable. Records a corollary: "just deploy a Series III instead" works partly because a MiniMate Plus has a DB-9 port directly on the unit, with no USB-to-serial adapter in the path and therefore no chipset to get wrong. That workaround has been routing around this exact failure mode. Co-Authored-By: Claude Opus 5 Claude-Session: https://claude.ai/code/session_01Ru8Lg9HkkYvX9VWWo65SmL --- docs/micromate_protocol_reference.md | 42 ++++++++++++++++++++-------- 1 file changed, 31 insertions(+), 11 deletions(-) diff --git a/docs/micromate_protocol_reference.md b/docs/micromate_protocol_reference.md index b9e8610..396dd70 100644 --- a/docs/micromate_protocol_reference.md +++ b/docs/micromate_protocol_reference.md @@ -2119,20 +2119,40 @@ FTDI is VID `0403`, Prolific is `067b`. Note also that counterfeit FTDI chips are common in cheap cables — they carry FTDI's VID but may not behave like one, and an embedded host with a single driver is far less forgiving than Linux. -### Does this explain the 2026-09-22 field outage? +### ✅ This accounts for the 2026-09-22 failure -⚠ **Not on the timeline as reported.** A Prolific cable does not fail -*gradually* — it never enumerates, so the modem port never works at all. The -unit was described as working at first and degrading. +An earlier draft of this section said the timeline did not fit, because the unit +was described as *working at first and then degrading* — which a Prolific cable +cannot do, since it never enumerates at all. -There is one story where it fits: if the initial success was over a **different -path** — the USB **PC** port, or a bench test before deployment — that would work -regardless of which serial cable was attached. The modem path would then have -been broken from the moment it was deployed, and "it worked and then stopped" -would be a recollection conflating two connection types days after the fact. +**The timeline was the thing that needed correcting, not the finding.** From the +operator, 2026-09-25: -Plausible, unverified, and recorded as such. Identifying that unit's cable would -settle it. +1. Initial setup — **one** modem, **one** cable. Worked: configs sent, status + read, no trouble. +2. Two Micromates then had to be deployed, so a **second cable** was fetched to + run both at once. +3. **Only one of the two ever worked.** The other would not talk over its modem + at any point. +4. That unit was never deployed — a **MiniMate Plus was put out in its place**, + and the Micromate came back to the bench. +5. The cable on that bench unit is a **Benfei (Prolific PL2303)**. + +So nothing degraded. The "worked at first" was the original single-cable setup; +the failure began when the pair was split across two cables and one of them was +the wrong chipset. **One working and one not, set up side by side, is the +signature of a mixed cable supply** — not of a unit fault. + +⚠ Still worth confirming: whether that cable travelled home *with* the unit, or +was picked up separately at the bench. If it travelled with it, there is no +inference left. Either way the FTDI cable arriving 2026-09-26 settles it — same +unit, same modem, one variable. + +**Corollary worth knowing.** The standing workaround — *"just deploy a Series III +instead"* — works partly because a **MiniMate Plus has a DB-9 port directly on the +unit.** No USB-to-serial adapter anywhere in the path, so there is no chipset to +get wrong. That workaround has been quietly routing around this exact failure +mode. ### How this was isolated — the method is reusable