CLAUDE.md

@@ -307,10 +307,16 @@ producing only ~1071 bytes instead of ~2126.
 
 ### SUB 1A — anchor search range
 
-`_decode_compliance_config_into()` locates sample_rate and record_time via the anchor
-`b'\x01\x2c\x00\x00\xbe\x80\x00\x00\x00\x00'`. Search range is `cfg[0:150]`.
+`_decode_compliance_config_into()` locates fields via the **6-byte stable anchor**
+`b'\xbe\x80\x00\x00\x00\x00'`. Search range is `cfg[0:150]`.
 
-Do not narrow this to `cfg[40:100]` — the old range was only accidentally correct because
+**IMPORTANT — the "10-byte anchor" `\x01\x2c\x00\x00\xbe\x80\x00\x00\x00\x00` is NOT fully constant.**
+The first 2 bytes (`\x01\x2c` = 300) are the `histogram_interval_sec` field (uint16 BE, seconds) —
+the value 300 is just the 5-minute default. When histogram interval is set to a different value
+(e.g. 15min = 0x0384 = `\x03\x84`), those bytes change. Only the 6-byte suffix
+`\xbe\x80\x00\x00\x00\x00` is truly constant. The code already uses the 6-byte anchor.
+
+Do not narrow the search range to `cfg[40:100]` — the old range was only accidentally correct because
 the orphaned-send bug was prepending a 44-byte spurious header, pushing the anchor from
 its real position (cfg[11]) into the 40–100 window.
 
@@ -360,8 +366,9 @@ Do NOT use fixed absolute offsets for sample_rate or record_time.
 
 | Field | How to find it |
 |---|---|
-| **recording_mode** | **uint8 at anchor − 3 (write payload) / anchor − 4 (read response)** ✅ confirmed 2026-04-20 |
+| **recording_mode** | **uint8 at anchor − 3 (write) / anchor − 4 (read)** ✅ confirmed 2026-04-20 |
 | sample_rate | uint16 BE at anchor − 2 |
+| **histogram_interval_sec** | **uint16 BE at anchor − 4 (seconds); same offset in read & write** ✅ confirmed 2026-04-20 |
 | record_time | float32 BE at anchor + 10 |
 | trigger_level_geo | float32 BE, located in channel block |
 | alarm_level_geo | float32 BE, adjacent to trigger_level_geo |
@@ -370,7 +377,20 @@ Do NOT use fixed absolute offsets for sample_rate or record_time.
 | setup_name | ASCII, null-padded, in cfg body |
 | project / client / operator / sensor_location | ASCII, label-value pairs |
 
-Anchor: `b'\x01\x2c\x00\x00\xbe\x80\x00\x00\x00\x00'`, search `cfg[0:150]`
+**True stable anchor: `b'\xbe\x80\x00\x00\x00\x00'` (6-byte suffix), search `cfg[0:150]`.**
+The old "10-byte anchor" `b'\x01\x2c\x00\x00\xbe\x80\x00\x00\x00\x00'` is partially variable:
+bytes `\x01\x2c` = 300 (5-minute default histogram interval); changes when interval changes.
+
+**Field layout relative to the 6-byte anchor (write payload / E5 read — noted where different):**
+
+| Offset | Field | Format | Notes |
+|---|---|---|---|
+| anchor − 7 (write) / anchor − 8 (read) | recording_mode | uint8 | E5 read has extra `0x10` at anchor−7 |
+| anchor − 6 | sample_rate | uint16 BE | same in read & write |
+| anchor − 4 | histogram_interval_sec | uint16 BE | seconds; same in read & write ✅ 2026-04-20 |
+| anchor − 2 | `0x00 0x00` | padding | |
+| anchor | `\xbe\x80\x00\x00\x00\x00` | anchor | |
+| anchor + 6 | record_time | float32 BE | same in read & write |
 
 **recording_mode enum** (confirmed 2026-04-20 from 4-20-26 captures):
 
@@ -382,7 +402,7 @@ Anchor: `b'\x01\x2c\x00\x00\xbe\x80\x00\x00\x00\x00'`, search `cfg[0:150]`
 | `0x03` | Histogram |
 | `0x04` | Histogram + Continuous |
 
-**Offset note:** The write payload (SUB 71 cfg) has recording_mode 3 bytes before the anchor (`anchor_pos − 3`). The E5 read response has it 4 bytes before (`anchor_pos − 4`), with an extra `0x10` byte sitting between recording_mode and sample_rate in the read format. Use `anchor_pos − 3` when encoding writes; use `anchor_pos − 4` when decoding reads.
+**DLE escaping in write frames — CONFIRMED 2026-04-20:** Write frame data payloads DO escape `0x03` (ETX) bytes with a `0x10` DLE prefix. For histogram_interval = 900 (0x0384), the wire carries `10 03 84` — the `0x03` high byte is preceded by a DLE escape. After DLE destuffing (`10 XX → XX`), the logical field value is correctly `03 84` = 900. The CLAUDE.md claim that write frame data is "written RAW" was incorrect; at minimum ETX (0x03) bytes are escaped. S3FrameParser handles this transparently so the decoded `compliance_raw` always contains logical (destuffed) bytes.
 
 ### SUB 0C — Waveform Record (210 bytes = data[11:11+0xD2])
 
@@ -721,7 +741,7 @@ offsets in the raw 1A/E5 payload.  Only fields with `✅` have confirmed offsets
 - Record Stop Mode: Fixed Record Time / Auto / Manual Stop (enum) ❓ (byte near recording_mode; data[40] in E5 sf1 changed 0x01→0x00 alongside Continuous→Single Shot — may be this field)
 - Sample Rate: Standard 1024 / Fast 2048 / Faster 4096 sps ✅ (anchor−2)
 - Record Time: float, seconds ✅ (anchor+10)
-- Histogram Interval: 5 / 15 / 30 / 60 minutes (enum, mode-gated)
+- Histogram Interval: 2s / 5s / 15s / 1m / 5m / 15m ✅ (uint16 BE seconds at anchor−4, same in read & write; mode-gated to Histogram/Histogram+Continuous) — confirmed 2026-04-20
 - Storage Mode: Save All Data / Save Triggered (enum)
 - Geophone Type: Standard Triaxial / 4.5 Hz (bool/enum)
 - Geophone Channels: Enable all geophones (bool), Trigger Source (bool)

minimateplus/client.py

@@ -850,6 +850,7 @@ class MiniMateClient:
         recording_mode:         Optional[int]   = None,
         sample_rate:            Optional[int]   = None,
         record_time:            Optional[float] = None,
+        histogram_interval_sec: Optional[int]   = None,
         # Threshold parameters (geo channels, in/s)
         trigger_level_geo: Optional[float] = None,
         alarm_level_geo:   Optional[float] = None,
@@ -919,6 +920,7 @@ class MiniMateClient:
             recording_mode=recording_mode,
             sample_rate=sample_rate,
             record_time=record_time,
+            histogram_interval_sec=histogram_interval_sec,
             trigger_level_geo=trigger_level_geo,
             alarm_level_geo=alarm_level_geo,
             project=project,
@@ -1658,6 +1660,7 @@ def _encode_compliance_config(
     record_time:       Optional[float] = None,
     trigger_level_geo: Optional[float] = None,
     alarm_level_geo:      Optional[float] = None,
+    histogram_interval_sec: Optional[int] = None,
     project:              Optional[str]   = None,
     client_name:          Optional[str]   = None,
     operator:             Optional[str]   = None,
@@ -1674,12 +1677,13 @@ def _encode_compliance_config(
     DLE-jitter shifts):
 
       Anchor: b'\\xbe\\x80\\x00\\x00\\x00\\x00'  (confirmed stable, both BE11529 and BE18189)
-        recording_mode → uint8 at anchor_pos - 7  (write payload; one byte earlier than read format)
+        recording_mode       → uint8 at anchor_pos - 7  (write payload)
                                Values: 0x00=Single Shot, 0x01=Continuous, 0x03=Histogram, 0x04=Histogram+Continuous
-                         NOTE: In the E5 read response the field is at anchor_pos - 8 due to an extra
-                         0x10 byte at anchor_pos - 7 present only in the read format.  The write
-                         payload does NOT have this extra byte — use anchor_pos - 7 here.
+                               NOTE: In the E5 read response (decode) field is at anchor_pos - 8 due to an
+                               extra 0x10 byte at read anchor_pos - 7.  Write payload has no extra byte.
         sample_rate          → uint16 BE at anchor_pos - 6
+        histogram_interval_sec → uint16 BE at anchor_pos - 4  (seconds; mode-gated to Histogram/Histogram+Continuous)
+                               Valid values: 2, 5, 15, 60, 300, 900 (= 2s, 5s, 15s, 1m, 5m, 15m)
         record_time          → float32 BE at anchor_pos + 6
 
       Channel block (anchored on b"Tran" with unit-string guard):
@@ -1730,6 +1734,14 @@ def _encode_compliance_config(
             struct.pack_into(">H", buf, _anc - 6, sample_rate)
             log.debug("_encode_compliance_config: sample_rate=%d -> offset %d", sample_rate, _anc - 6)
 
+    if histogram_interval_sec is not None:
+        if _anc < 4:
+            log.warning("_encode_compliance_config: anchor not found — cannot write histogram_interval")
+        else:
+            struct.pack_into(">H", buf, _anc - 4, histogram_interval_sec)
+            log.debug("_encode_compliance_config: histogram_interval=%ds -> offset %d",
+                      histogram_interval_sec, _anc - 4)
+
     if record_time is not None:
         if _anc < 0 or _anc + 10 > len(buf):
             log.warning("_encode_compliance_config: anchor not found — cannot write record_time")
@@ -1841,29 +1853,27 @@ def _decode_compliance_config_into(data: bytes, info: DeviceInfo) -> None:
     except Exception as exc:
         log.warning("compliance_config: setup_name extraction failed: %s", exc)
 
-    # ── Record time + sample rate — anchor-relative ───────────────────────────
-    # The 10-byte anchor sits between sample_rate and record_time in the cfg.
-    # Absolute offsets are NOT reliable because sample_rate = 4096 (0x1000) is
-    # DLE-escaped in the raw S3 frame (10 10 00 → 10 00 after unstuffing),
-    # making frame C 1 byte shorter than for 1024/2048 and shifting everything.
-    #   sample_rate: uint16_BE at anchor - 2
-    #   record_time: float32_BE at anchor + 10
-    # 6-byte suffix anchor — confirmed stable across BE11529 and bench unit (BE18189).
-    # The preceding 4 bytes (old anchor prefix 01 2c / 00 3c) vary by unit config;
-    # only be 80 00 00 00 00 is constant.
-    #   sample_rate : uint16 BE at anchor_pos - 6
-    #   record_time : float32 BE at anchor_pos + 6
+    # ── recording_mode / sample_rate / histogram_interval / record_time ─────────
+    # 6-byte stable anchor: b'\xbe\x80\x00\x00\x00\x00' — confirmed across BE11529
+    # and BE18189. The 4 bytes immediately before the anchor are NOT constant:
+    # bytes -4:-2 are the histogram_interval (uint16 BE, seconds), and bytes -2:0
+    # are zero padding.  The old "10-byte anchor" (\x01\x2c\x00\x00 prefix) was
+    # only constant when the histogram interval happened to be 5 min (0x012C = 300).
+    #
+    # E5 read format layout relative to 6-byte anchor:
+    #   _anchor - 8 : recording_mode     (uint8)
+    #   _anchor - 7 : 0x10               (extra byte E5 read only; absent in SUB 71 write)
+    #   _anchor - 6 : sample_rate_hi     (uint16 BE, MSB)
+    #   _anchor - 5 : sample_rate_lo     (uint16 BE, LSB)
+    #   _anchor - 4 : histogram_interval_hi  (uint16 BE, seconds, MSB)
+    #   _anchor - 3 : histogram_interval_lo  (uint16 BE, seconds, LSB)
+    #   _anchor - 2 : 0x00               (padding)
+    #   _anchor - 1 : 0x00               (padding)
+    #   _anchor     : \xbe\x80\x00\x00\x00\x00  (6-byte anchor)
+    #   _anchor + 6 : record_time        (float32 BE)
     _ANCHOR = b'\xbe\x80\x00\x00\x00\x00'
     _anchor = data.find(_ANCHOR, 0, 150)
     if _anchor >= 8 and _anchor + 10 <= len(data):
-        # Layout (E5 read format, relative to 6-byte anchor suffix):
-        #   _anchor - 8 : recording_mode  (uint8)
-        #   _anchor - 7 : 0x10            (extra byte present in E5 read only; absent in SUB 71 write)
-        #   _anchor - 6 : sample_rate_hi  (uint8, MSB of uint16 BE)
-        #   _anchor - 5 : sample_rate_lo  (uint8, LSB of uint16 BE)
-        #   _anchor - 4 : \x01\x2c\x00\x00  (10-byte anchor prefix)
-        #   _anchor     : \xbe\x80\x00\x00\x00\x00  (6-byte anchor suffix)
-        #   _anchor + 6 : record_time     (float32 BE)
         try:
             config.recording_mode = data[_anchor - 8]
             log.debug(
@@ -1878,6 +1888,14 @@ def _decode_compliance_config_into(data: bytes, info: DeviceInfo) -> None:
             )
         except Exception as exc:
             log.warning("compliance_config: sample_rate extraction failed: %s", exc)
+        try:
+            config.histogram_interval_sec = struct.unpack_from(">H", data, _anchor - 4)[0]
+            log.debug(
+                "compliance_config: histogram_interval = %d s (anchor@%d)",
+                config.histogram_interval_sec, _anchor
+            )
+        except Exception as exc:
+            log.warning("compliance_config: histogram_interval extraction failed: %s", exc)
         try:
             config.record_time = struct.unpack_from(">f", data, _anchor + 6)[0]
             log.debug(

minimateplus/models.py

@@ -340,10 +340,14 @@ class ComplianceConfig:
     # Recording parameters (✅ CONFIRMED from §7.6)
     recording_mode: Optional[int] = None  # uint8: 0x00=Single Shot, 0x01=Continuous,
                                            # 0x03=Histogram, 0x04=Histogram+Continuous ✅ confirmed 2026-04-20
-                                           # Read (E5 sf1): data[anchor_pos - 4]
-                                           # Write (SUB 71 payload): cfg[anchor_pos - 3]
-    record_time: Optional[float] = None   # seconds (7.0, 10.0, 13.0, etc.)
-    sample_rate: Optional[int] = None     # sps (1024, 2048, 4096, etc.)
+                                           # Read (E5): data[anchor_pos - 8] (6-byte anchor)
+                                           # Write (SUB 71): data[anchor_pos - 7]
+    sample_rate: Optional[int] = None     # sps (1024, 2048, 4096)
+    histogram_interval_sec: Optional[int] = None  # uint16 BE, seconds ✅ confirmed 2026-04-20
+                                                   # anchor_pos - 4 (same offset in read & write)
+                                                   # Valid values: 2, 5, 15, 60, 300, 900
+                                                   # Mode-gated: only active in Histogram/Histogram+Continuous
+    record_time: Optional[float] = None   # seconds (e.g. 3.0, 5.0, 8.0, 10.0)
 
     # Trigger/alarm levels (✅ CONFIRMED per-channel at §7.6)
     # For now we store the first geo channel (Transverse) as representatives;

sfm/server.py

@@ -286,8 +286,9 @@ def _serialise_compliance_config(cc: Optional["ComplianceConfig"]) -> Optional[d
         return None
     return {
         "recording_mode":        cc.recording_mode,  # 0x00=Single Shot, 0x01=Continuous, 0x03=Histogram, 0x04=Histogram+Continuous
-        "record_time":        cc.record_time,
         "sample_rate":           cc.sample_rate,
+        "histogram_interval_sec": cc.histogram_interval_sec,  # seconds; None if not Histogram mode
+        "record_time":           cc.record_time,
         "trigger_level_geo":  cc.trigger_level_geo,
         "alarm_level_geo":    cc.alarm_level_geo,
         "geo_adc_scale": cc.geo_adc_scale,  # hw scale factor (in/s)/V — informational only, do not write
@@ -857,6 +858,7 @@ class DeviceConfigBody(BaseModel):
     recording_mode:         Optional[int]   = None
     sample_rate:            Optional[int]   = None
     record_time:            Optional[float] = None
+    histogram_interval_sec: Optional[int]   = None  # seconds: 2, 5, 15, 60, 300, 900 (mode-gated)
     # Threshold parameters
     trigger_level_geo: Optional[float] = None
     alarm_level_geo:   Optional[float] = None
@@ -918,6 +920,7 @@ def device_config(
                     recording_mode=body.recording_mode,
                     sample_rate=body.sample_rate,
                     record_time=body.record_time,
+                    histogram_interval_sec=body.histogram_interval_sec,
                     trigger_level_geo=body.trigger_level_geo,
                     alarm_level_geo=body.alarm_level_geo,
                     project=body.project,

sfm/sfm_webapp.html

@@ -824,6 +824,20 @@
         </select>
       </div>
 
+      <div class="cfg-field">
+        <label>Histogram Interval</label>
+        <select id="cfg-histogram-interval">
+          <option value="">— unchanged —</option>
+          <option value="2">2 seconds</option>
+          <option value="5">5 seconds</option>
+          <option value="15">15 seconds</option>
+          <option value="60">1 minute</option>
+          <option value="300">5 minutes</option>
+          <option value="900">15 minutes</option>
+        </select>
+        <div class="hint">Only active in Histogram / Histogram + Continuous mode</div>
+      </div>
+
       <div class="cfg-field">
         <label>Record Time (seconds)</label>
         <input type="number" id="cfg-record-time" step="0.5" min="0.5" max="60" placeholder="e.g. 3.0" />
@@ -1336,6 +1350,7 @@ function populateDeviceTab() {
   const complianceRows = [
     ['Recording Mode',        cc.recording_mode != null ? (RECORDING_MODE_LABELS[cc.recording_mode] || `0x${cc.recording_mode.toString(16).padStart(2,'0')}`) : '—'],
     ['Sample Rate',           cc.sample_rate != null ? `${cc.sample_rate} sps` : '—'],
+    ['Histogram Interval',    cc.histogram_interval_sec != null ? (() => { const s = cc.histogram_interval_sec; return s < 60 ? `${s}s` : `${s/60}m`; })() : '—'],
     ['Record Time',           cc.record_time != null ? `${cc.record_time.toFixed(2)} s` : '—'],
     ['Trigger Level (geo)',   cc.trigger_level_geo != null ? `${cc.trigger_level_geo.toFixed(4)} in/s` : '—'],
     ['Alarm Level (geo)',     cc.alarm_level_geo != null   ? `${cc.alarm_level_geo.toFixed(4)} in/s` : '—'],
@@ -1372,6 +1387,7 @@ function populateConfigFromDeviceInfo() {
   const cc = unitInfo.compliance_config || {};
   if (cc.recording_mode != null)        qs('cfg-recording-mode', String(cc.recording_mode));
   if (cc.sample_rate)                   qs('cfg-sample-rate', String(cc.sample_rate));
+  if (cc.histogram_interval_sec != null) qs('cfg-histogram-interval', String(cc.histogram_interval_sec));
   if (cc.record_time != null)           qs('cfg-record-time', cc.record_time.toFixed(1));
   if (cc.trigger_level_geo != null) qs('cfg-trigger',  cc.trigger_level_geo.toFixed(4));
   if (cc.alarm_level_geo   != null) qs('cfg-alarm',    cc.alarm_level_geo.toFixed(4));
@@ -1417,6 +1433,8 @@ async function writeConfig() {
   if (rm !== '') body.recording_mode = parseInt(rm, 10);
   const sr = qs('cfg-sample-rate').value;
   if (sr) body.sample_rate = parseInt(sr, 10);
+  const hi = qs('cfg-histogram-interval').value;
+  if (hi !== '') body.histogram_interval_sec = parseInt(hi, 10);
   const rt = qs('cfg-record-time').value;
   if (rt) body.record_time = parseFloat(rt);
   const trig = qs('cfg-trigger').value;