CHANGELOG.md

@@ -17,6 +17,27 @@ backfill**: a report regenerated for an existing event simply gains the new
 panels.
 
 ### Added
+- **Rescue-on-connect for `bridges/ach_server.py`** — `--stop-monitoring`
+  (SUB 0x97), `--disable-ach` (SUB 0x2C read → 0x7E write → 0x7F confirm) and
+  `--rescue` (both).  They fire immediately after the startup handshake and
+  **before** the event walk, so a unit that is recording back-to-back on a
+  stuck-triggered geophone is quieted as early in the session as possible.
+  Each action is independently guarded — a failure does not abort the download
+  — and the outcome is written to `rescue.json` in the session directory.
+
+  This inverts the `docs/runbooks/wedged_unit_recovery.md` approach.  That
+  runbook reaches the unit *inbound* and clears the modem's Destination Address
+  to stop it dialing.  When the device is instead wedged mid-modem-init — ALEOS
+  logs `tcpmode trying to send to invalid socket` and re-runs `Initialize Auto
+  answer` every ~75 s, orphaning any held inbound session — inbound cannot win.
+  Pointing the modem's Destination at an `ach_server` and letting the unit call
+  *us* gives a device-initiated session the modem bridges properly.
+
+  ⚠ Prefer `--stop-monitoring` alone on first contact.  `--disable-ach` stops
+  the unit calling, which is the only channel to a unit in this state; stopping
+  the recording ends the call-home loop on its own when ACH is
+  "after event recorded".
+
 - **Blastware-compatible channel FFT (`waveform_fft`).** Reproduces Blastware's
   FFT Report: DC-removed, no window, zero-padded to 4096 (0.25 Hz bins at
   1024 sps), single-sided `2/N` amplitude. Matches Blastware's dominant

bridges/ach_server.py

@@ -177,6 +177,8 @@ class AchSession:
         store: "WaveformStore",
         clear_after_download: bool = False,
         restart_monitoring: bool = False,
+        rescue_stop_monitoring: bool = False,
+        rescue_disable_ach: bool = False,
         force_redownload: bool = False,
     ) -> None:
         self.sock                 = sock
@@ -190,6 +192,9 @@ class AchSession:
         self.store                = store
         self.clear_after_download = clear_after_download
         self.restart_monitoring   = restart_monitoring
+        # Rescue actions for a runaway unit — fired before the event walk.
+        self.rescue_stop_monitoring = rescue_stop_monitoring
+        self.rescue_disable_ach     = rescue_disable_ach
         # `force_redownload` tells this session to ignore ach_state and
         # re-download every event currently on the device, regardless of any
         # (key, timestamp) match.  Useful as a manual override when state has
@@ -290,6 +295,41 @@ class AchSession:
         root_logger.addHandler(fh)
 
         try:
+            # ── Step 1.5: rescue actions ──────────────────────────────────────
+            # Fired BEFORE the event walk so a runaway unit is quieted as early
+            # in the session as possible.  A unit whose geophone sits above the
+            # trigger threshold records back-to-back and, with ACH set to "after
+            # event recorded", re-dials every time — saturating its own firmware
+            # so it never services inbound requests.  See
+            # docs/runbooks/wedged_unit_recovery.md.
+            #
+            # Each action is independently guarded: a failure here must not
+            # abort the download that follows.
+            if self.rescue_stop_monitoring or self.rescue_disable_ach:
+                rescue: dict = {"peer": self.peer, "ts": ts}
+
+                if self.rescue_stop_monitoring:
+                    log.info("Step 1.5: RESCUE — stop monitoring (SUB 0x97)")
+                    try:
+                        client.stop_monitoring()
+                        rescue["stop_monitoring"] = "ok"
+                        log.info("  stop monitoring OK — device should stop recording")
+                    except Exception as exc:
+                        rescue["stop_monitoring"] = f"failed: {exc}"
+                        log.error("  stop monitoring FAILED: %s", exc)
+
+                if self.rescue_disable_ach:
+                    log.info("Step 1.5: RESCUE — disable auto call home (SUB 0x2C/0x7E/0x7F)")
+                    try:
+                        client.set_call_home_config(auto_call_home_enabled=False)
+                        rescue["disable_ach"] = "ok"
+                        log.info("  disable ACH OK — unit should stop calling home")
+                    except Exception as exc:
+                        rescue["disable_ach"] = f"failed: {exc}"
+                        log.error("  disable ACH FAILED: %s", exc)
+
+                _save_json(session_dir / "rescue.json", rescue)
+
             # ── Step 2: device info ───────────────────────────────────────────
             device_info = None
             if not self.events_only:
@@ -747,6 +787,13 @@ def serve(args: argparse.Namespace) -> None:
     print(f"  Max events per session: {max_ev if max_ev else 'unlimited'}")
     print(f"  Clear device after download: {'YES' if args.clear_after_download else 'no'}")
     print(f"  Restart monitoring after download: {'YES' if args.restart_monitoring else 'no'}")
+    _stop_mon = args.stop_monitoring or args.rescue
+    _dis_ach  = args.disable_ach or args.rescue
+    print(f"  RESCUE stop monitoring on connect:  {'YES' if _stop_mon else 'no'}")
+    print(f"  RESCUE disable auto call home:      {'YES' if _dis_ach else 'no'}")
+    if _stop_mon and args.restart_monitoring:
+        print("  !! --restart-monitoring will re-start the unit after download,")
+        print("     undoing --stop-monitoring.  Drop one of them.")
     print(f"  Force re-download all (ignore state): {'YES' if args.force_redownload_all else 'no'}")
     print(f"{'='*60}")
     print(f"\n  Point your test unit's ACEmanager call-home settings to:")
@@ -788,6 +835,8 @@ def serve(args: argparse.Namespace) -> None:
                     store=store,
                     clear_after_download=args.clear_after_download,
                     restart_monitoring=args.restart_monitoring,
+                    rescue_stop_monitoring=args.stop_monitoring or args.rescue,
+                    rescue_disable_ach=args.disable_ach or args.rescue,
                     force_redownload=args.force_redownload_all,
                 )
                 t = threading.Thread(target=session.run, daemon=True, name=f"ach-{peer}")
@@ -862,6 +911,32 @@ def parse_args() -> argparse.Namespace:
             "DCD on disconnect — without this the unit stays idle after a call-home."
         ),
     )
+    p.add_argument(
+        "--stop-monitoring",
+        action="store_true",
+        default=False,
+        help=(
+            "RESCUE: send SUB 0x97 (stop monitoring) immediately after the "
+            "handshake, before any event download. Use on a unit that is "
+            "recording back-to-back because of a stuck-triggered geophone."
+        ),
+    )
+    p.add_argument(
+        "--disable-ach",
+        action="store_true",
+        default=False,
+        help=(
+            "RESCUE: disable Auto Call Home on the device (SUB 0x2C read → "
+            "0x7E write → 0x7F confirm) immediately after the handshake. The "
+            "unit stops dialing out until ACH is explicitly re-enabled."
+        ),
+    )
+    p.add_argument(
+        "--rescue",
+        action="store_true",
+        default=False,
+        help="Shorthand for --stop-monitoring --disable-ach.",
+    )
     p.add_argument(
         "--clear-after-download",
         action="store_true",