fix: backup box sensors missing on MIN/TL-XH + diagnostic scanner DTC bypass (#352)

Two bugs preventing backup box sensors from appearing on MIN 4200TL-XH:

1. read_all_data() never populated box_* GrowattData fields
   The 3000-range registers (3281-3342) were read into _register_cache correctly
   by the gap-detection chunker, but there was no code mapping cache -> dataclass.
   All 10 box_* fields stayed at default 0 permanently, so box_connect_flag was
   always 0 and the deferred sensor mechanism never added the 8 conditional sensors.
   Fix: add _read_backup_box_data() method called from read_all_data().

2. Diagnostic scanner overwrote correct DTC result with MOD heuristic
   DTC 5100 correctly identifies TL-XH. When register 30099 = 0 (legacy protocol),
   confidence is downgraded from Very High to High. The early-return guard checked
   confidence == Very High so it fired only on the non-downgraded path, allowing
   register heuristics to re-classify the device as MOD 6000-15000TL3-XH.
   Fix: guard now checks dtc_code + profile_key presence instead of confidence level.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: 0xAHA

README.md

@@ -3,7 +3,7 @@
 # Growatt Modbus Integration for Home Assistant ☀️
 
 ![HACS Badge](https://img.shields.io/badge/HACS-Custom-orange.svg)
-![Version](https://img.shields.io/badge/Version-1.0.12-blue.svg)
+![Version](https://img.shields.io/badge/Version-1.0.13-blue.svg)
 [![GitHub Issues](https://img.shields.io/github/issues/0xAHA/Growatt_ModbusTCP.svg)](https://github.com/0xAHA/Growatt_ModbusTCP/issues)
 [![GitHub Stars](https://img.shields.io/github/stars/0xAHA/Growatt_ModbusTCP.svg?style=social)](https://github.com/0xAHA/Growatt_ModbusTCP)
 

RELEASENOTES.md

@@ -4,6 +4,33 @@
 
 ---
 
+## v1.0.13
+
+Issues: #352
+
+- **Fix: backup box sensors now appear on MIN/TL-XH inverters (#352):**
+  All 9 backup box sensors (`box_bypass_status`, `box_work_mode`, `box_error_code`,
+  `box_warning_code`, `box_temperature`, `box_grid_voltage`, `box_grid_power`,
+  `box_load_power`, `box_relay_status`) were missing from Home Assistant despite the
+  hardware reporting live data. Root cause: `read_all_data()` cached the 3000-range
+  registers correctly but had no code to map them into the `GrowattData` dataclass fields —
+  all 10 `box_*` fields remained permanently at their default value of 0. Adds a new
+  `_read_backup_box_data()` method that populates all backup box fields from the register
+  cache using the existing `_find_register_by_name` / `_get_register_value` pattern.
+  Only `box_connect_flag` must be non-zero for the other 8 conditional sensors to appear;
+  `box_connect_flag` itself is always created so its value is always visible.
+
+- **Fix: diagnostic scanner correctly identifies MIN/TL-XH when DTC confidence is downgraded (#352):**
+  The DTC-based detection correctly identifies a MIN 4200TL-XH as `tl_xh_3000_10000_v201`
+  (DTC 5100 → "Very High" confidence). However, when register 30099 reads 0 (legacy
+  protocol), confidence is downgraded to "High" to indicate the legacy profile variant should
+  be used. The early-return guard checked `confidence == "Very High"` and therefore missed
+  the downgraded case, allowing register heuristics to overwrite the correct DTC result with
+  "MOD 6000-15000TL3-XH (Hybrid)". Fixed by checking `detection.get("dtc_code") and
+  detection.get("profile_key")` instead — any matched DTC always wins over heuristics.
+
+---
+
 ## v1.0.12
 
 Issues: #351

custom_components/growatt_modbus/diagnostic.py

@@ -1517,8 +1517,10 @@ def reg_exists(addr):
             if protocol_ver >= 201:
                 detection["reasoning"].append(f"  → VPP Protocol V{protocol_str} - supports advanced features")
 
-    # If DTC detected model, skip other detection logic
-    if detection["confidence"] == "Very High":
+    # If DTC detected model, skip other detection logic.
+    # Also returns when confidence was downgraded to "High" by proto_ver==0 — a matched DTC
+    # always wins over register heuristics regardless of protocol version confidence.
+    if detection.get("dtc_code") and detection.get("profile_key"):
         return detection
 
     # Check register ranges (only successful reads with non-zero values)

custom_components/growatt_modbus/growatt_modbus.py

@@ -1892,7 +1892,10 @@ def _read_sparse(addr_list: list, fatal: bool = False) -> bool:
 
             # Battery Data (if available - storage/hybrid models)
             self._read_battery_data(data)
-            
+
+            # Backup Box Data (Growatt ARK transfer switch, regs 3281-3342)
+            self._read_backup_box_data(data)
+
             # Temperatures
             inverter_temp_addr = self._find_register_by_name('inverter_temp')
             ipm_temp_addr = self._find_register_by_name('ipm_temp')
@@ -2996,6 +2999,63 @@ def _read_battery_data(self, data: GrowattData) -> None:
         except Exception as e:
             logger.debug(f"Battery data not available: {e}")
 
+    def _read_backup_box_data(self, data: GrowattData) -> None:
+        """Populate backup box (Growatt ARK) fields from cached 3000-range registers."""
+        try:
+            # Connection flag — must be read first so sensors.py deferred mechanism
+            # can gate the remaining 8 conditional sensors on box_connect_flag == 1.
+            addr = self._find_register_by_name('box_connect_flag')
+            if addr is None:
+                return  # Profile has no backup box registers — skip entirely
+            value = self._get_register_value(addr)
+            if value is not None:
+                data.box_connect_flag = int(value)
+
+            for attr, reg_name in (
+                ('box_bypass_status', 'box_bypass_status'),
+                ('box_work_mode',     'box_work_mode'),
+                ('box_error_code',    'box_error_code'),
+                ('box_warning_code',  'box_warning_code'),
+                ('box_relay_status',  'box_relay_status'),
+            ):
+                a = self._find_register_by_name(reg_name)
+                if a is not None:
+                    v = self._get_register_value(a)
+                    if v is not None:
+                        setattr(data, attr, int(v))
+
+            for attr, reg_name in (
+                ('box_temperature',   'box_temperature'),
+                ('box_grid_voltage',  'box_grid_voltage'),
+            ):
+                a = self._find_register_by_name(reg_name)
+                if a is not None:
+                    v = self._get_register_value(a)
+                    if v is not None:
+                        setattr(data, attr, float(v))
+
+            # 32-bit paired: call _get_register_value on the _low address
+            for attr, low_name in (
+                ('box_grid_power', 'box_grid_power_low'),
+                ('box_load_power', 'box_load_power_low'),
+            ):
+                a = self._find_register_by_name(low_name)
+                if a is not None:
+                    v = self._get_register_value(a)
+                    if v is not None:
+                        setattr(data, attr, float(v))
+
+            if data.box_connect_flag:
+                logger.debug(
+                    "Backup box: connect=%d bypass=%d mode=%d temp=%.0f°C "
+                    "grid=%.0fW load=%.0fW relay=%d",
+                    data.box_connect_flag, data.box_bypass_status, data.box_work_mode,
+                    data.box_temperature, data.box_grid_power, data.box_load_power,
+                    data.box_relay_status,
+                )
+        except Exception as e:
+            logger.debug(f"Backup box data not available: {e}")
+
     def _read_device_info(self, data: GrowattData) -> None:
         """Read device info from holding registers"""
 

custom_components/growatt_modbus/manifest.json

@@ -12,5 +12,5 @@
     "pymodbus>=3.0.0",
     "pyserial>=3.4"
   ],
-  "version": "1.0.12"
+  "version": "1.0.13"
 }