diff --git a/apps/autocal/config/locales/en_US.json b/apps/autocal/config/locales/en_US.json
index aac4235..3193ff4 100644
--- a/apps/autocal/config/locales/en_US.json
+++ b/apps/autocal/config/locales/en_US.json
@@ -51,7 +51,8 @@
     "press_set": "Calibrated: press target = zero ± contact height.",
     "press_unset": "Not calibrated: Execute holds the press axis.",
     "close": "Close",
-    "chip_hint": "Open device setup — {name}"
+    "chip_hint": "Open device setup — {name}",
+    "tab_units": "Units"
   },
   "move": {
     "execute": "Execute",
@@ -164,7 +165,25 @@
     "home": "Home",
     "controls": "Actions",
     "mm_derived_tip": "Millimetres are derived from the pulse equivalent: a display value, not a calibrated length.",
-    "enabled_count": "{on}/{total} axes enabled"
+    "enabled_count": "{on}/{total} axes enabled",
+    "units_open": "Units…",
+    "units_locked_tip": "Units are locked and read-only here. Use Device setup → Units and press Modify to change them.",
+    "events_title": "Alarms and events",
+    "events_clear": "Clear log",
+    "events_empty": "No events yet. Changes in alarms, enable, homing, read failures and unit mismatches are logged here.",
+    "ev_connected": "Controller connected",
+    "ev_disconnected": "Controller disconnected",
+    "ev_alarm_on": "Axis {axis} alarm",
+    "ev_alarm_off": "Axis {axis} alarm cleared",
+    "ev_enabled": "Axis {axis} enabled",
+    "ev_disabled": "Axis {axis} disabled",
+    "ev_read_failed": "Axis {axis} read failed: {detail}",
+    "ev_read_ok": "Axis {axis} readable again",
+    "ev_home_started": "Axis {axis} homing started",
+    "ev_home_done": "Axis {axis} homing complete",
+    "ev_home_incomplete": "Axis {axis} homing ended without reporting complete",
+    "ev_units_mismatch": "Axis {axis} UNITS mismatch: configured {expected}, read {observed}",
+    "ev_units_ok": "Axis {axis} UNITS agree again"
   },
   "busdata": {
     "title": "Bus data exchange",
@@ -911,5 +930,49 @@
       "close": "Close",
       "max_required": "Required; the program does not assume a value"
     }
+  },
+  "units": {
+    "hint": "One place to check each direction's drive, its pulse equivalent (UNITS) and the resulting scale. Locked and read-only by default; press Modify to change a value, and the change is listed for confirmation before anything is written.",
+    "col_role": "Direction",
+    "col_axis": "Drive",
+    "col_kind": "Type",
+    "col_configured": "Configured UNITS",
+    "col_observed": "Controller read-back",
+    "col_scale": "Scale",
+    "col_check": "Check",
+    "kind_linear": "Linear (mm)",
+    "kind_rotary": "Rotary (°)",
+    "scale_linear": "1 unit = {mm} mm; {per} units/mm",
+    "scale_rotary": "1 unit = {deg}°; {per} units/°",
+    "status_ok": "Agree",
+    "status_unread": "Not read",
+    "status_mismatch": "Mismatch",
+    "status_uncalibrated": "No angle scale",
+    "status_invalid": "Invalid",
+    "status_unmapped": "Unmapped",
+    "tip_unread": "Not connected, or this axis's UNITS has not been read back yet.",
+    "tip_mismatch": "The controller reads a different UNITS from the configured one: pose moves are refused and targets are not rescaled.",
+    "tip_uncalibrated": "The rotary angle scale was only measured at the calibration equivalent; any other value needs a new calibration.",
+    "tip_invalid": "UNITS must be a finite number above 0.",
+    "tip_unmapped": "No drive is assigned to this direction; see Axis mapping.",
+    "summary_ok": "Unit check: all {total} directions agree",
+    "summary_bad": "Unit check: {bad} of {total} directions need attention",
+    "summary_unread": "Unit check: not read yet (not connected)",
+    "constants": "Fixed calibration constants (measured on the bench, not editable here): linear axes {ppm} pulses/mm; rotary axes {rotary}; all measured at UNITS={cal}. Millimetres and degrees are displayed values derived from these constants, not new measurements.",
+    "rotary_item": "axis {axis}: {units} user units = 90°",
+    "modify": "Modify",
+    "apply": "Apply to controller",
+    "cancel": "Cancel",
+    "modify_offline": "Not connected to a controller; nothing can be modified.",
+    "locked_note": "Locked: read-only.",
+    "unlocked_note": "Unlocked: enter new values in the Configured UNITS column, then press Apply to controller.",
+    "mapping_changed": "The axis mapping changed; unapplied edits were dropped and the page is locked again.",
+    "invalid": "UNITS for {role} is not valid: enter a number above 0.",
+    "no_change": "No change; locked again.",
+    "applied": "Submitted UNITS for {count} drive(s); the read-back will show after the next refresh.",
+    "change_line": "{role} · axis {axis}: {old} → {new}",
+    "confirm_title": "Write UNITS",
+    "confirm_body": "The following UNITS will be written to the controller:\n{changes}\n\nAfterwards every millimetre and degree reading, and every pose-move target, is recomputed with the new equivalent. Confirm that the platform is stopped and the mechanical ratio has been checked.",
+    "confirm_rotary": "Note: UNITS for {roles} is not the calibration equivalent {cal}; the rotary axis has no angle scale at that value, so pose moves are refused until it is recalibrated."
   }
 }
diff --git a/apps/autocal/config/locales/zh_CN.json b/apps/autocal/config/locales/zh_CN.json
index 159158c..8f9c95d 100644
--- a/apps/autocal/config/locales/zh_CN.json
+++ b/apps/autocal/config/locales/zh_CN.json
@@ -51,7 +51,8 @@
     "press_set": "已标定：压轴目标 = 零点 ± 接触高度。",
     "press_unset": "未标定：执行动作会保持压轴不动。",
     "close": "关闭",
-    "chip_hint": "点击打开设备设置 — {name}"
+    "chip_hint": "点击打开设备设置 — {name}",
+    "tab_units": "单位与换算"
   },
   "move": {
     "execute": "执行动作",
@@ -164,7 +165,25 @@
     "home": "启动回零",
     "controls": "操作",
     "mm_derived_tip": "毫米值由脉冲当量换算得出，是显示值，不是标定长度。",
-    "enabled_count": "已使能 {on}/{total} 轴"
+    "enabled_count": "已使能 {on}/{total} 轴",
+    "units_open": "单位与换算…",
+    "units_locked_tip": "单位已锁定，这里只读。到“设备设置 → 单位与换算”点“修改”才能更改。",
+    "events_title": "报警与事件",
+    "events_clear": "清空记录",
+    "events_empty": "暂无事件。报警、使能、回零、读取失败和单位不一致发生变化时，会记录在这里。",
+    "ev_connected": "控制器已连接",
+    "ev_disconnected": "控制器已断开",
+    "ev_alarm_on": "轴 {axis} 报警",
+    "ev_alarm_off": "轴 {axis} 报警已解除",
+    "ev_enabled": "轴 {axis} 已使能",
+    "ev_disabled": "轴 {axis} 已关闭使能",
+    "ev_read_failed": "轴 {axis} 读取失败：{detail}",
+    "ev_read_ok": "轴 {axis} 读取恢复",
+    "ev_home_started": "轴 {axis} 开始回零",
+    "ev_home_done": "轴 {axis} 回零完成",
+    "ev_home_incomplete": "轴 {axis} 回零结束，但未报告完成",
+    "ev_units_mismatch": "轴 {axis} UNITS 不一致：配置 {expected}，读回 {observed}",
+    "ev_units_ok": "轴 {axis} UNITS 已一致"
   },
   "busdata": {
     "title": "总线数据交互",
@@ -911,5 +930,49 @@
       "close": "关闭",
       "max_required": "必须填写，程序不预设"
     }
+  },
+  "units": {
+    "hint": "集中检查每个方向用的驱动器、脉冲当量（UNITS）和换算。默认锁定为只读；需要改动时点“修改”，写入前会列出改动并要求确认。",
+    "col_role": "方向",
+    "col_axis": "驱动器",
+    "col_kind": "类型",
+    "col_configured": "配置 UNITS",
+    "col_observed": "控制器读回",
+    "col_scale": "换算",
+    "col_check": "检查",
+    "kind_linear": "线性 (mm)",
+    "kind_rotary": "旋转 (°)",
+    "scale_linear": "1 单位 = {mm} mm；{per} 单位/mm",
+    "scale_rotary": "1 单位 = {deg}°；{per} 单位/°",
+    "status_ok": "一致",
+    "status_unread": "未读回",
+    "status_mismatch": "不一致",
+    "status_uncalibrated": "无角度标定",
+    "status_invalid": "配置无效",
+    "status_unmapped": "未映射",
+    "tip_unread": "未连接，或该轴的 UNITS 尚未成功读回。",
+    "tip_mismatch": "控制器读回的 UNITS 与配置不同：姿态移动会被拒绝，不会重新换算目标。",
+    "tip_uncalibrated": "旋转轴的角度比例只在标定当量下测量过；其他值需要重新标定。",
+    "tip_invalid": "UNITS 必须是大于 0 的有限数。",
+    "tip_unmapped": "该方向没有分配驱动器，见“轴映射”。",
+    "summary_ok": "单位检查：{total} 个方向全部一致",
+    "summary_bad": "单位检查：{bad}/{total} 个方向需要处理",
+    "summary_unread": "单位检查：尚未读回（未连接）",
+    "constants": "固定标定常数（来自实机测量，不能在此修改）：线性轴 {ppm} 脉冲/mm；旋转轴 {rotary}；以上在 UNITS={cal} 下测得。毫米与角度都是由这些常数换算的显示值，不是新的测量。",
+    "rotary_item": "轴 {axis}：{units} 用户单位 = 90°",
+    "modify": "修改",
+    "apply": "应用到控制器",
+    "cancel": "取消",
+    "modify_offline": "未连接控制器，无法修改。",
+    "locked_note": "已锁定：只读显示。",
+    "unlocked_note": "已解锁：在“配置 UNITS”列输入新值，然后点“应用到控制器”。",
+    "mapping_changed": "轴映射已改变，未应用的修改已放弃并重新锁定。",
+    "invalid": "{role} 的 UNITS 无效：需要大于 0 的数字。",
+    "no_change": "没有改动，已重新锁定。",
+    "applied": "已提交 {count} 个驱动器的 UNITS；读回结果将在下一次刷新后显示。",
+    "change_line": "{role} · 轴 {axis}：{old} → {new}",
+    "confirm_title": "写入 UNITS",
+    "confirm_body": "将向控制器写入以下 UNITS：\n{changes}\n\n写入后，全部毫米和角度读数以及姿态移动的目标都按新当量重新计算。请确认平台已停止，并已核对机械传动比。",
+    "confirm_rotary": "注意：{roles} 的 UNITS 不是标定当量 {cal}，旋转轴在该当量下没有角度标定，姿态移动会被拒绝，直到重新标定。"
   }
 }
diff --git a/apps/autocal/src/orisys_autocal/motion/events.py b/apps/autocal/src/orisys_autocal/motion/events.py
new file mode 100644
index 0000000..f431a68
--- /dev/null
+++ b/apps/autocal/src/orisys_autocal/motion/events.py
@@ -0,0 +1,205 @@
+"""Edges worth remembering from the controller's poll stream (Qt-free).
+
+The axis table shows *now*. An alarm that came and went between two glances, a
+drive that stopped answering for a second, or a homing run that ended without
+completing leaves nothing on screen, and the operator is left with a machine that
+"did something". The tracker turns the poll stream into a short list of dated
+events: only changes, never one line per poll.
+
+Nothing here talks to the controller; it reads :class:`~.models.Snapshot` values.
+"""
+
+from __future__ import annotations
+
+import math
+import time
+from collections.abc import Callable, Mapping
+from dataclasses import dataclass, field
+
+from .models import AxisState, Snapshot
+
+#: Event kinds. The page maps each one to a locale string.
+CONNECTED = "connected"
+DISCONNECTED = "disconnected"
+ALARM_ON = "alarm_on"
+ALARM_OFF = "alarm_off"
+ENABLED = "enabled"
+DISABLED = "disabled"
+READ_FAILED = "read_failed"
+READ_OK = "read_ok"
+HOME_STARTED = "home_started"
+HOME_DONE = "home_done"
+HOME_INCOMPLETE = "home_incomplete"
+UNITS_MISMATCH = "units_mismatch"
+UNITS_OK = "units_ok"
+
+#: How serious each kind is, for the colour the page gives the line.
+SEVERITY = {
+    CONNECTED: "info",
+    DISCONNECTED: "warning",
+    ALARM_ON: "error",
+    ALARM_OFF: "info",
+    ENABLED: "info",
+    DISABLED: "info",
+    READ_FAILED: "warning",
+    READ_OK: "info",
+    HOME_STARTED: "info",
+    HOME_DONE: "info",
+    HOME_INCOMPLETE: "warning",
+    UNITS_MISMATCH: "error",
+    UNITS_OK: "info",
+}
+
+#: Platform-wide events carry this instead of an axis number.
+NO_AXIS = -1
+
+
+@dataclass(frozen=True)
+class AxisEvent:
+    """One dated change. ``detail`` is raw data (a reason, a number), not prose."""
+
+    time: float
+    axis: int
+    kind: str
+    detail: str = ""
+
+    @property
+    def severity(self) -> str:
+        return SEVERITY.get(self.kind, "info")
+
+
+@dataclass
+class _AxisMemory:
+    alarm: bool
+    enabled: bool
+    read_ok: bool
+    homing: bool
+    units_ok: bool | None
+
+
+@dataclass
+class AxisEventTracker:
+    """Remember the last state of each axis and report what changed."""
+
+    limit: int = 200
+    clock: Callable[[], float] = time.time
+    _events: list[AxisEvent] = field(default_factory=list)
+    _connected: bool | None = None
+    _axes: dict[int, _AxisMemory] = field(default_factory=dict)
+
+    @property
+    def events(self) -> list[AxisEvent]:
+        """Oldest first."""
+        return list(self._events)
+
+    def clear(self) -> None:
+        self._events.clear()
+
+    def update(
+        self,
+        snapshot: Snapshot,
+        expected_units: Mapping[int, float] | None = None,
+    ) -> list[AxisEvent]:
+        """Compare one poll with the previous one; return and keep the new events."""
+        fresh: list[AxisEvent] = []
+        now = float(self.clock())
+
+        def emit(axis: int, kind: str, detail: str = "") -> None:
+            fresh.append(AxisEvent(now, axis, kind, detail))
+
+        if self._connected is not None and snapshot.connected != self._connected:
+            emit(NO_AXIS, CONNECTED if snapshot.connected else DISCONNECTED)
+        self._connected = snapshot.connected
+
+        if not snapshot.connected:
+            # Whatever the axes did while the link was down is unknown: forget them,
+            # so the first poll after a reconnect is a baseline and not a flood.
+            self._axes.clear()
+        else:
+            for state in snapshot.axes:
+                self._update_axis(state, expected_units, emit)
+
+        self._events.extend(fresh)
+        if len(self._events) > self.limit:
+            del self._events[: len(self._events) - self.limit]
+        return fresh
+
+    def _update_axis(self, state: AxisState, expected_units, emit) -> None:
+        axis = state.axis
+        memory = self._axes.get(axis)
+        units_ok = self._units_ok(state, expected_units)
+        current = _AxisMemory(
+            alarm=bool(state.read_ok and state.status.alarm),
+            enabled=bool(state.read_ok and state.enabled),
+            read_ok=bool(state.read_ok),
+            homing=bool(state.read_ok and state.status.home_in_progress),
+            units_ok=units_ok,
+        )
+        if memory is None:
+            # The first sight of an axis is a baseline, except for the two facts that
+            # matter whenever they are true: an alarm already raised, and a drive that
+            # cannot be read.
+            if current.alarm:
+                emit(axis, ALARM_ON)
+            if not current.read_ok:
+                emit(axis, READ_FAILED, state.error)
+            if units_ok is False:
+                emit(axis, UNITS_MISMATCH, _units_detail(state, expected_units))
+            self._axes[axis] = current
+            return
+
+        if current.read_ok != memory.read_ok:
+            if current.read_ok:
+                emit(axis, READ_OK)
+            else:
+                emit(axis, READ_FAILED, state.error)
+        if current.read_ok and memory.read_ok:
+            if current.alarm != memory.alarm:
+                emit(axis, ALARM_ON if current.alarm else ALARM_OFF)
+            if current.enabled != memory.enabled:
+                emit(axis, ENABLED if current.enabled else DISABLED)
+            if current.homing != memory.homing:
+                if current.homing:
+                    emit(axis, HOME_STARTED)
+                else:
+                    emit(axis, HOME_DONE if state.home_status == 1 else HOME_INCOMPLETE)
+        if units_ok is not None and units_ok != memory.units_ok:
+            if units_ok:
+                if memory.units_ok is False:
+                    emit(axis, UNITS_OK)
+            else:
+                emit(axis, UNITS_MISMATCH, _units_detail(state, expected_units))
+        self._axes[axis] = current
+
+    @staticmethod
+    def _units_ok(state: AxisState, expected_units) -> bool | None:
+        """``None`` when there is nothing to compare, else whether the two agree."""
+        if expected_units is None or not state.read_ok:
+            return None
+        expected = expected_units.get(state.axis)
+        if expected is None:
+            return None
+        try:
+            expected = float(expected)
+        except (TypeError, ValueError):
+            return None
+        if not math.isfinite(expected) or expected <= 0:
+            return None
+        observed = float(state.units)
+        return bool(
+            math.isfinite(observed)
+            and observed > 0
+            and math.isclose(expected, observed, rel_tol=1e-7, abs_tol=0.0)
+        )
+
+
+def _units_detail(state: AxisState, expected_units) -> str:
+    expected = (expected_units or {}).get(state.axis)
+    return f"{_g(expected)}|{_g(state.units)}"
+
+
+def _g(value: object) -> str:
+    try:
+        return f"{float(value):g}"
+    except (TypeError, ValueError):
+        return "—"
diff --git a/apps/autocal/src/orisys_autocal/motion/unit_report.py b/apps/autocal/src/orisys_autocal/motion/unit_report.py
new file mode 100644
index 0000000..697e9ad
--- /dev/null
+++ b/apps/autocal/src/orisys_autocal/motion/unit_report.py
@@ -0,0 +1,128 @@
+"""What the platform's unit settings say, one row per direction (Qt-free).
+
+The motion guards already refuse a move when the configured pulse equivalent
+(``UNITS``) and the one the controller reports disagree. This module answers the
+operator's question *before* a move is refused: which direction uses which drive,
+what ``UNITS`` is configured, what the controller reads back, what one user unit
+means in millimetres or degrees, and whether all of it holds together.
+
+The verdicts follow :meth:`MotionService.units_problem` in the same order, so the
+page and the guard cannot disagree about what is wrong. Nothing here writes to a
+controller or changes a setting.
+"""
+
+from __future__ import annotations
+
+import math
+from collections.abc import Callable, Mapping
+from dataclasses import dataclass
+
+from .models import Snapshot
+from .service import AXIS_ROLES, LINEAR_ROLES
+from .units import PULSES_PER_MM, units_per_degree
+
+#: Relative tolerance of the expected-versus-read-back comparison. The guard uses
+#: the same number; a different one here would show "ok" for a move it refuses.
+UNITS_TOLERANCE = 1e-7
+
+OK = "ok"
+UNREAD = "unread"
+MISMATCH = "mismatch"
+UNCALIBRATED = "uncalibrated"
+INVALID = "invalid"
+UNMAPPED = "unmapped"
+
+
+@dataclass(frozen=True)
+class UnitRow:
+    """One direction's unit facts.
+
+    ``per_unit`` is millimetres (linear) or degrees (rotary) per controller user
+    unit, ``per_mm`` the inverse (user units per millimetre or per degree). Both
+    are NaN when the setting does not define them.
+    """
+
+    role: str
+    axis: int
+    kind: str
+    expected: float
+    observed: float | None
+    status: str
+    per_unit: float
+    per_mm: float
+
+    @property
+    def ok(self) -> bool:
+        return self.status == OK
+
+
+def build_unit_rows(
+    roles: Mapping[str, int],
+    expected_of: Callable[[int], float],
+    snapshot: Snapshot | None,
+) -> list[UnitRow]:
+    """One row per platform direction, in the order the machine is described."""
+    rows: list[UnitRow] = []
+    for role in AXIS_ROLES:
+        kind = "linear" if role in LINEAR_ROLES else "rotary"
+        axis = roles.get(role)
+        if axis is None:
+            rows.append(UnitRow(role, -1, kind, math.nan, None, UNMAPPED, math.nan, math.nan))
+            continue
+        axis = int(axis)
+        expected = _number(expected_of(axis))
+        observed = _observed(snapshot, axis)
+        per_unit, per_mm = _scale(kind, axis, expected)
+        status = _status(kind, axis, expected, observed)
+        rows.append(UnitRow(role, axis, kind, expected, observed, status, per_unit, per_mm))
+    return rows
+
+
+def summarise(rows: list[UnitRow]) -> tuple[int, int, list[UnitRow]]:
+    """``(rows that are fine, rows in all, the rows that are not)``."""
+    problems = [row for row in rows if not row.ok]
+    return len(rows) - len(problems), len(rows), problems
+
+
+def _number(value: object) -> float:
+    try:
+        return float(value)
+    except (TypeError, ValueError):
+        return math.nan
+
+
+def _observed(snapshot: Snapshot | None, axis: int) -> float | None:
+    if snapshot is None or not snapshot.connected:
+        return None
+    state = snapshot.axis(axis)
+    if state is None or not state.read_ok:
+        return None
+    return float(state.units)
+
+
+def _scale(kind: str, axis: int, expected: float) -> tuple[float, float]:
+    """Per-unit and per-millimetre (or per-degree) factors for the configured value."""
+    if not math.isfinite(expected) or expected <= 0:
+        return math.nan, math.nan
+    if kind == "linear":
+        return expected / PULSES_PER_MM, PULSES_PER_MM / expected
+    per_degree = units_per_degree(axis, units=expected)
+    if not math.isfinite(per_degree) or per_degree <= 0:
+        return math.nan, math.nan
+    return 1.0 / per_degree, per_degree
+
+
+def _status(kind: str, axis: int, expected: float, observed: float | None) -> str:
+    if not math.isfinite(expected) or expected <= 0:
+        return INVALID
+    if kind == "rotary" and not math.isfinite(units_per_degree(axis, units=expected)):
+        return UNCALIBRATED
+    if observed is None:
+        return UNREAD
+    if (
+        not math.isfinite(observed)
+        or observed <= 0
+        or not math.isclose(expected, observed, rel_tol=UNITS_TOLERANCE, abs_tol=0.0)
+    ):
+        return MISMATCH
+    return OK
diff --git a/apps/autocal/src/orisys_autocal/ui/axis_panel.py b/apps/autocal/src/orisys_autocal/ui/axis_panel.py
index dfbd5ff..0638b5f 100644
--- a/apps/autocal/src/orisys_autocal/ui/axis_panel.py
+++ b/apps/autocal/src/orisys_autocal/ui/axis_panel.py
@@ -15,6 +15,9 @@ five-axis platform, acting on the wrong axis is the expensive mistake.
 from __future__ import annotations
 
 import math
+import time
+from collections.abc import Iterable, Mapping
+from dataclasses import replace
 
 from orisys_app_shared.i18n import t
 from PySide6.QtCore import Qt, Signal
@@ -25,6 +28,8 @@ from PySide6.QtWidgets import (
     QHBoxLayout,
     QLabel,
     QLineEdit,
+    QListWidget,
+    QListWidgetItem,
     QPushButton,
     QTableWidget,
     QTableWidgetItem,
@@ -42,6 +47,8 @@ from ..motion import (
     safe_float,
     user_units_to_mm,
 )
+from ..motion.events import UNITS_MISMATCH, AxisEvent, AxisEventTracker
+from ..motion.unit_report import UNREAD, UnitRow, summarise
 
 #: Data columns in the state table, in display order.
 #:
@@ -113,6 +120,8 @@ class AxisPanel(QGroupBox):
     moveRelRequested = Signal(int, float)
     homeRequested = Signal(int)
     clearAlarmRequested = Signal(int)
+    #: The operator wants the unit settings (shown and changed in the device setup).
+    unitsRequested = Signal()
 
     def __init__(
         self,
@@ -133,6 +142,8 @@ class AxisPanel(QGroupBox):
         self._selected_axis = 0
         self._snapshot = Snapshot()
         self._rows: list[dict] = []
+        self._tracker = AxisEventTracker()
+        self._unit_rows: list[UnitRow] = []
 
         outer = QVBoxLayout(self)
         outer.setContentsMargins(10, 8, 10, 10)
@@ -140,11 +151,12 @@ class AxisPanel(QGroupBox):
 
         outer.addWidget(self._build_params())
         outer.addWidget(self._build_target_row())
-        # Stretch factor 1: the table is the only part of this panel that may
-        # grow, so every spare pixel goes to a further axis row rather than to
-        # padding around the parameter form.
-        outer.addWidget(self._build_table(), 1)
+        # The table is exactly as tall as its axis rows: the spare height belongs to
+        # the event log below, which is where an operator looks after something went
+        # wrong, and not to blank rows nobody can use.
+        outer.addWidget(self._build_table())
         outer.addWidget(self._build_actions())
+        outer.addWidget(self._build_events(), 1)
 
         self.retranslate()
         self._reread_params()
@@ -181,6 +193,10 @@ class AxisPanel(QGroupBox):
 
         self.units_label = label("axes.units")
         self.units_edit = edit(80)
+        # Units are shown here and changed in the device setup, where they are locked
+        # until the operator asks to modify them: a pulse equivalent typed into a form
+        # that is always live rescales every position the machine is told about.
+        self.units_edit.setReadOnly(True)
         self.speed_label = label("axes.speed")
         self.speed_edit = edit(80)
         self.accel_label = label("axes.accel")
@@ -211,6 +227,12 @@ class AxisPanel(QGroupBox):
             lambda: self.clearAlarmRequested.emit(self.selected_axis)
         )
 
+        self.units_button = QPushButton(box)
+        self.units_button.setObjectName("axisUnitsOpen")
+        self.units_button.setProperty("rail", True)
+        self.units_button.setFixedHeight(FIELD_HEIGHT)
+        self.units_button.clicked.connect(self.unitsRequested)
+
         grid.addWidget(self.axis_label, 0, 0)
         grid.addWidget(self.axis_index_label, 0, 1)
         grid.addWidget(self.units_label, 0, 2)
@@ -232,6 +254,7 @@ class AxisPanel(QGroupBox):
         grid.addWidget(self.apply_button, 2, 0, 1, 2)
         grid.addWidget(self.home_button, 2, 2, 1, 2)
         grid.addWidget(self.clear_alarm_button, 2, 4, 1, 2)
+        grid.addWidget(self.units_button, 2, 6, 1, 2)
         return box
 
     def _build_target_row(self) -> QWidget:
@@ -275,6 +298,7 @@ class AxisPanel(QGroupBox):
         # and the splitter then clips the last drive — which reads as a missing
         # axis. The table scrolls if it is ever squeezed below this.
         self.table.setMinimumHeight(40 + ROW_HEIGHT * MIN_VISIBLE_ROWS)
+        self.table.setMaximumHeight(40 + ROW_HEIGHT * max(self.axis_count, MIN_VISIBLE_ROWS) + 4)
         self.table.cellClicked.connect(self._on_cell_clicked)
 
         for row in range(self.axis_count):
@@ -347,6 +371,97 @@ class AxisPanel(QGroupBox):
         column.addLayout(row)
         return box
 
+    def _build_events(self) -> QWidget:
+        box = QWidget(self)
+        column = QVBoxLayout(box)
+        column.setContentsMargins(0, 0, 0, 0)
+        column.setSpacing(4)
+        header = QHBoxLayout()
+        header.setSpacing(8)
+        self.events_title = QLabel(box)
+        self.events_title.setObjectName("statusValue")
+        self.units_chip = QLabel(box)
+        self.units_chip.setObjectName("hintLabel")
+        self.units_chip.setWordWrap(True)
+        self.clear_events_button = QPushButton(box)
+        self.clear_events_button.setObjectName("axisEventsClear")
+        self.clear_events_button.setProperty("rail", True)
+        self.clear_events_button.setFixedHeight(FIELD_HEIGHT)
+        self.clear_events_button.clicked.connect(self._on_clear_events)
+        header.addWidget(self.events_title)
+        header.addWidget(self.units_chip, 1)
+        header.addWidget(self.clear_events_button)
+        column.addLayout(header)
+        self.event_log = QListWidget(box)
+        self.event_log.setObjectName("axisEventLog")
+        self.event_log.setSelectionMode(QListWidget.SelectionMode.NoSelection)
+        self.event_log.setAlternatingRowColors(True)
+        self.event_log.setMinimumHeight(90)
+        column.addWidget(self.event_log, 1)
+        self.events_empty = QLabel(box)
+        self.events_empty.setObjectName("hintLabel")
+        self.events_empty.setWordWrap(True)
+        column.addWidget(self.events_empty)
+        return box
+
+    # ------------------------------------------------------------------ events
+
+    def _append_event(self, event: AxisEvent) -> None:
+        stamp = time.strftime("%H:%M:%S", time.localtime(event.time))
+        item = QListWidgetItem(f"{stamp}  {event_text(event)}")
+        colour = _EVENT_COLOURS.get(event.severity)
+        if colour:
+            item.setForeground(QBrush(QColor(colour)))
+        self.event_log.insertItem(0, item)
+        while self.event_log.count() > self._tracker.limit:
+            self.event_log.takeItem(self.event_log.count() - 1)
+
+    def _render_events(self) -> None:
+        """Rebuild the list from the tracker (language change, clear)."""
+        self.event_log.clear()
+        for event in self._tracker.events:
+            self._append_event(event)
+        self.events_empty.setVisible(self.event_log.count() == 0)
+
+    def _on_clear_events(self) -> None:
+        self._tracker.clear()
+        self._render_events()
+
+    def set_unit_rows(self, rows: Iterable[UnitRow], connected: bool) -> None:
+        """One line about the unit check; the full table lives in the device setup."""
+        self._unit_rows = list(rows)
+        if not self._unit_rows:
+            self.units_chip.setText("")
+            return
+        _good, total, problems = summarise(self._unit_rows)
+        if not problems:
+            self.units_chip.setText(t("units.summary_ok", total=total))
+        elif all(row.status == UNREAD for row in problems):
+            self.units_chip.setText(t("units.summary_unread"))
+        else:
+            self.units_chip.setText(
+                t("units.summary_bad", bad=len(problems), total=total)
+            )
+
+    def apply_units(self, changes: Mapping[int, float]) -> None:
+        """Send confirmed unit changes through the ordinary axis-parameter path."""
+        for axis, value in sorted(changes.items()):
+            if not 0 <= int(axis) < self.axis_count:
+                continue
+            params = replace(self._params.get(int(axis), AxisParams()), units=float(value))
+            self._params[int(axis)] = params
+            self.paramsApplied.emit(int(axis), params)
+        self._reread_params()
+
+    def expected_units(self, axis: int) -> float:
+        """The pulse equivalent configured for a drive."""
+        return self._params.get(int(axis), AxisParams()).units
+
+    @property
+    def snapshot(self) -> Snapshot:
+        """The last poll the panel rendered."""
+        return self._snapshot
+
     # ------------------------------------------------------------------- state
 
     @property
@@ -473,6 +588,10 @@ class AxisPanel(QGroupBox):
         )
         self._refresh_availability()
         self._recolour_rows()
+        expected = {axis: self.expected_units(axis) for axis in range(self.axis_count)}
+        for event in self._tracker.update(snapshot, expected):
+            self._append_event(event)
+        self.events_empty.setVisible(self.event_log.count() == 0)
 
     def _detail_text(self) -> str:
         """Everything about the selected axis that the seven columns cannot hold.
@@ -571,6 +690,12 @@ class AxisPanel(QGroupBox):
         self.move_rel_button.setText(t("axes.move_rel"))
         self.stop_all_button.setText(t("axes.stop_all"))
         self.mm_hint.setText(t("axes.mm_derived_tip"))
+        self.units_button.setText(t("axes.units_open"))
+        self.units_edit.setToolTip(t("axes.units_locked_tip"))
+        self.events_title.setText(t("axes.events_title"))
+        self.clear_events_button.setText(t("axes.events_clear"))
+        self.events_empty.setText(t("axes.events_empty"))
+        self._render_events()
         if hasattr(self, "_detail_label"):
             self._detail_label.setText(self._detail_text())
         self.table.setHorizontalHeaderLabels(
@@ -584,6 +709,19 @@ class AxisPanel(QGroupBox):
             self._rows[row]["stop_button"].setText(t("axes.stop"))
 
 
+#: Line colours for the event log. Info lines keep the theme's own text colour.
+_EVENT_COLOURS = {"error": "#c62828", "warning": "#b26a00"}
+
+
+def event_text(event: AxisEvent) -> str:
+    """One event as a sentence in the current language."""
+    fields: dict[str, object] = {"axis": event.axis, "detail": event.detail}
+    if event.kind == UNITS_MISMATCH:
+        expected, _, observed = event.detail.partition("|")
+        fields.update(expected=expected or "—", observed=observed or "—")
+    return t(f"axes.ev_{event.kind}", **fields)
+
+
 def _number(value: float, places: int) -> str:
     try:
         return f"{float(value):.{places}f}"
diff --git a/apps/autocal/src/orisys_autocal/ui/device_setup.py b/apps/autocal/src/orisys_autocal/ui/device_setup.py
index 34df33b..8c58e62 100644
--- a/apps/autocal/src/orisys_autocal/ui/device_setup.py
+++ b/apps/autocal/src/orisys_autocal/ui/device_setup.py
@@ -43,6 +43,7 @@ from ..motion import ConnectionSpec
 from ..motion.service import AXIS_ROLES, DEFAULT_AXIS_ROLES, PLATFORM_AXES
 from .bus_panel import BusPanel
 from .connection_panel import ConnectionPanel
+from .units_page import UnitsPage
 
 #: Tab identity -> locale key, in the order they are shown. The order is the work:
 #: reach the machine, bring its bus up, then say what each drive moves and how the
@@ -52,6 +53,7 @@ TABS: tuple[tuple[str, str], ...] = (
     ("bus", "setup.tab_bus"),
     ("axes", "setup.tab_axes"),
     ("press", "setup.tab_press"),
+    ("units", "setup.tab_units"),
 )
 
 #: Role -> locale key for the mapping rows.
@@ -311,6 +313,7 @@ class DeviceSetupDialog(QDialog):
         self.bus_panel = BusPanel(bas_path, self.tabs)
         self.roles_page = AxisRolesPage(roles, self.tabs)
         self.press_page = PressAxisPage(press, self.tabs)
+        self.units_page = UnitsPage(self.tabs)
         for key, locale_key in TABS:
             self.tabs.addTab(self.panel(key), "")
         column.addWidget(self.tabs, 1)
@@ -331,11 +334,13 @@ class DeviceSetupDialog(QDialog):
     # ----------------------------------------------------------------- content
 
     def panel(self, key: str) -> QWidget:
-        """One of the four pages, by tab key."""
+        """One of the five pages, by tab key."""
         if key == "connection":
             return self.connection_panel
         if key == "bus":
             return self.bus_panel
+        if key == "units":
+            return self.units_page
         return self.roles_page if key == "axes" else self.press_page
 
     def open_for(self, tab: str | None = None) -> None:
@@ -402,3 +407,4 @@ class DeviceSetupDialog(QDialog):
         self.bus_panel.retranslate()
         self.roles_page.retranslate()
         self.press_page.retranslate()
+        self.units_page.retranslate()
diff --git a/apps/autocal/src/orisys_autocal/ui/units_page.py b/apps/autocal/src/orisys_autocal/ui/units_page.py
new file mode 100644
index 0000000..2e1b4a4
--- /dev/null
+++ b/apps/autocal/src/orisys_autocal/ui/units_page.py
@@ -0,0 +1,405 @@
+"""The units page of the device setup: what the platform's scales are, and whether they hold.
+
+Every millimetre and degree the app shows or commands is *derived* from a drive's
+pulse equivalent (``UNITS``) and a measured constant. If the equivalent configured here
+and the one the controller reports differ, the motion guards refuse the move; this page
+puts the same facts in front of the operator one step earlier, so a wrong scale is seen
+at start-up and not as a refused move.
+
+It is **locked by default**. Changing ``UNITS`` rescales every position the machine is
+told about, so the cells are read-only until the operator presses *Modify*, and a change
+is written only after a confirmation that lists what will change. The page itself
+writes nothing: it emits :attr:`UnitsPage.unitsApplied` and the window sends the values
+through the same axis-parameter path the axis page uses.
+"""
+
+from __future__ import annotations
+
+import math
+from collections.abc import Iterable
+
+from orisys_app_shared.i18n import t
+from PySide6.QtCore import Qt, Signal
+from PySide6.QtGui import QBrush, QColor
+from PySide6.QtWidgets import (
+    QHBoxLayout,
+    QLabel,
+    QLineEdit,
+    QMessageBox,
+    QPushButton,
+    QTableWidget,
+    QTableWidgetItem,
+    QVBoxLayout,
+    QWidget,
+)
+
+from ..motion.unit_report import (
+    INVALID,
+    MISMATCH,
+    OK,
+    UNCALIBRATED,
+    UNMAPPED,
+    UNREAD,
+    UnitRow,
+    summarise,
+)
+from ..motion.units import (
+    PULSES_PER_MM,
+    ROTARY_CALIBRATION_UNITS,
+    ROTARY_UNITS_PER_90_DEG,
+)
+
+#: Table columns, in display order.
+COLUMNS = (
+    "units.col_role",
+    "units.col_axis",
+    "units.col_kind",
+    "units.col_configured",
+    "units.col_observed",
+    "units.col_scale",
+    "units.col_check",
+)
+CONFIGURED_COLUMN = 3
+ROW_HEIGHT = 34
+
+_ROLE_KEYS = {
+    "x": "setup.role_x",
+    "y": "setup.role_y",
+    "z": "setup.role_z",
+    "yaw": "setup.role_yaw",
+    "pitch": "setup.role_pitch",
+}
+_STATUS_KEYS = {
+    OK: "units.status_ok",
+    UNREAD: "units.status_unread",
+    MISMATCH: "units.status_mismatch",
+    UNCALIBRATED: "units.status_uncalibrated",
+    INVALID: "units.status_invalid",
+    UNMAPPED: "units.status_unmapped",
+}
+_TIP_KEYS = {
+    UNREAD: "units.tip_unread",
+    MISMATCH: "units.tip_mismatch",
+    UNCALIBRATED: "units.tip_uncalibrated",
+    INVALID: "units.tip_invalid",
+    UNMAPPED: "units.tip_unmapped",
+}
+_GOOD = "#2e7d32"
+_BAD = "#c62828"
+_QUIET = "#7a7a7a"
+
+
+def _g(value: float | None, places: int = 6) -> str:
+    """A number as the operator would write it, or a dash when there is none."""
+    if value is None:
+        return "—"
+    try:
+        number = float(value)
+    except (TypeError, ValueError):
+        return "—"
+    return f"{number:.{places}g}" if math.isfinite(number) else "—"
+
+
+class UnitsPage(QWidget):
+    """Read-only unit table with a guarded way to change it."""
+
+    #: ``{drive: new UNITS}`` for the drives the operator changed and confirmed.
+    unitsApplied = Signal(object)
+
+    def __init__(self, parent: QWidget | None = None) -> None:
+        super().__init__(parent)
+        self._rows: list[UnitRow] = []
+        self._connected = False
+        self._locked = True
+        self._unlocked_axes: dict[str, int] = {}
+        self._edits: dict[str, QLineEdit] = {}
+
+        column = QVBoxLayout(self)
+        column.setContentsMargins(8, 8, 8, 8)
+        column.setSpacing(8)
+
+        self.hint_label = QLabel(self)
+        self.hint_label.setObjectName("hintLabel")
+        self.hint_label.setWordWrap(True)
+        column.addWidget(self.hint_label)
+
+        top = QHBoxLayout()
+        top.setSpacing(8)
+        self.summary_label = QLabel(self)
+        self.summary_label.setObjectName("statusValue")
+        self.summary_label.setWordWrap(True)
+        self.modify_button = QPushButton(self)
+        self.modify_button.setObjectName("unitsModify")
+        self.modify_button.setProperty("rail", True)
+        self.modify_button.clicked.connect(self._unlock)
+        self.apply_button = QPushButton(self)
+        self.apply_button.setObjectName("unitsApply")
+        self.apply_button.setProperty("rail", True)
+        self.apply_button.clicked.connect(self._on_apply)
+        self.cancel_button = QPushButton(self)
+        self.cancel_button.setObjectName("unitsCancel")
+        self.cancel_button.setProperty("rail", True)
+        self.cancel_button.clicked.connect(self._on_cancel)
+        top.addWidget(self.summary_label, 1)
+        top.addWidget(self.modify_button)
+        top.addWidget(self.apply_button)
+        top.addWidget(self.cancel_button)
+        column.addLayout(top)
+
+        self.table = QTableWidget(5, len(COLUMNS), self)
+        self.table.setObjectName("unitsTable")
+        self.table.verticalHeader().setVisible(False)
+        self.table.setSelectionMode(QTableWidget.SelectionMode.NoSelection)
+        self.table.setEditTriggers(QTableWidget.EditTrigger.NoEditTriggers)
+        self.table.setAlternatingRowColors(True)
+        self.table.verticalHeader().setDefaultSectionSize(ROW_HEIGHT)
+        self.table.horizontalHeader().setStretchLastSection(True)
+        for index, width in enumerate((110, 60, 90, 110, 100, 230)):
+            self.table.setColumnWidth(index, width)
+        self.table.setMinimumHeight(40 + ROW_HEIGHT * 5 + 4)
+        for row in range(5):
+            for col in range(len(COLUMNS)):
+                if col != CONFIGURED_COLUMN:
+                    item = QTableWidgetItem("")
+                    if col in (1, 3, 4):
+                        item.setTextAlignment(Qt.AlignmentFlag.AlignCenter)
+                    self.table.setItem(row, col, item)
+        column.addWidget(self.table)
+
+        self.constants_label = QLabel(self)
+        self.constants_label.setObjectName("hintLabel")
+        self.constants_label.setWordWrap(True)
+        column.addWidget(self.constants_label)
+
+        self.message_label = QLabel(self)
+        self.message_label.setObjectName("hintLabel")
+        self.message_label.setWordWrap(True)
+        column.addWidget(self.message_label)
+        column.addStretch(1)
+
+        self._apply_lock()
+        self.retranslate()
+
+    # ------------------------------------------------------------------ data
+
+    @property
+    def locked(self) -> bool:
+        return self._locked
+
+    def set_rows(self, rows: Iterable[UnitRow], connected: bool) -> None:
+        """Show one poll's worth of unit facts.
+
+        While the page is unlocked the configured column belongs to the operator and
+        is not overwritten by a refresh; if the drive mapping changes underneath an
+        unlocked edit, the edit is abandoned instead of being applied to another drive.
+        """
+        self._rows = list(rows)
+        self._connected = bool(connected)
+        if not self._locked and {r.role: r.axis for r in self._rows} != self._unlocked_axes:
+            self._lock()
+            self.message_label.setText(t("units.mapping_changed"))
+        for index, row in enumerate(self._rows[: self.table.rowCount()]):
+            self._render_row(index, row)
+        self._render_summary()
+        self._apply_lock()
+
+    def _render_row(self, index: int, row: UnitRow) -> None:
+        def put(column: int, text: str, *, colour: str | None = None, tip: str = "") -> None:
+            item = self.table.item(index, column)
+            if item is None:
+                return
+            item.setText(text)
+            item.setToolTip(tip)
+            if colour:
+                item.setForeground(QBrush(QColor(colour)))
+            else:
+                item.setData(Qt.ItemDataRole.ForegroundRole, None)
+
+        put(0, t(_ROLE_KEYS.get(row.role, row.role)))
+        put(1, "—" if row.axis < 0 else str(row.axis))
+        put(2, t("units.kind_linear" if row.kind == "linear" else "units.kind_rotary"))
+        put(4, _g(row.observed, 6))
+        put(5, self._scale_text(row))
+        colour = _GOOD if row.ok else (_QUIET if row.status in {UNREAD, UNMAPPED} else _BAD)
+        put(
+            6,
+            t(_STATUS_KEYS[row.status]),
+            colour=colour,
+            tip=t(_TIP_KEYS[row.status]) if row.status in _TIP_KEYS else "",
+        )
+        edit = self._edit_for(index, row)
+        if edit is not None and (self._locked or not edit.isModified()):
+            edit.setText(_g(row.expected, 9))
+            edit.setModified(False)
+
+    def _edit_for(self, index: int, row: UnitRow) -> QLineEdit | None:
+        """The configured-UNITS cell of one direction, created on first use."""
+        if row.axis < 0:
+            if self._edits.pop(row.role, None) is not None:
+                self.table.removeCellWidget(index, CONFIGURED_COLUMN)
+            return None
+        edit = self._edits.get(row.role)
+        if edit is None:
+            edit = QLineEdit(self.table)
+            edit.setObjectName(f"unitsEdit_{row.role}")
+            edit.setAlignment(Qt.AlignmentFlag.AlignCenter)
+            edit.setFixedHeight(28)
+            self._edits[row.role] = edit
+            self.table.setCellWidget(index, CONFIGURED_COLUMN, edit)
+        edit.setReadOnly(self._locked)
+        return edit
+
+    @staticmethod
+    def _scale_text(row: UnitRow) -> str:
+        if not math.isfinite(row.per_unit) or not math.isfinite(row.per_mm):
+            return "—"
+        if row.kind == "linear":
+            return t("units.scale_linear", mm=_g(row.per_unit), per=_g(row.per_mm))
+        return t("units.scale_rotary", deg=_g(row.per_unit), per=_g(row.per_mm))
+
+    def _render_summary(self) -> None:
+        if not self._rows:
+            self.summary_label.setText("")
+            return
+        good, total, problems = summarise(self._rows)
+        only_unread = bool(problems) and all(row.status == UNREAD for row in problems)
+        if not problems:
+            self.summary_label.setText(t("units.summary_ok", total=total))
+            colour = _GOOD
+        elif only_unread:
+            self.summary_label.setText(t("units.summary_unread"))
+            colour = _QUIET
+        else:
+            self.summary_label.setText(
+                t("units.summary_bad", bad=len(problems), total=total)
+            )
+            colour = _BAD
+        self.summary_label.setStyleSheet(f"color: {colour};")
+
+    # ---------------------------------------------------------------- locking
+
+    def _apply_lock(self) -> None:
+        for edit in self._edits.values():
+            edit.setReadOnly(self._locked)
+        self.modify_button.setVisible(self._locked)
+        self.modify_button.setEnabled(self._connected)
+        self.modify_button.setToolTip("" if self._connected else t("units.modify_offline"))
+        self.apply_button.setVisible(not self._locked)
+        self.apply_button.setEnabled(self._connected)
+        self.cancel_button.setVisible(not self._locked)
+
+    def _unlock(self) -> None:
+        if not self._connected:
+            return
+        self._locked = False
+        self._unlocked_axes = {row.role: row.axis for row in self._rows}
+        self.message_label.setText(t("units.unlocked_note"))
+        self._apply_lock()
+
+    def _lock(self) -> None:
+        self._locked = True
+        self._unlocked_axes = {}
+        for row in self._rows:
+            edit = self._edits.get(row.role)
+            if edit is not None:
+                edit.setText(_g(row.expected, 9))
+                edit.setModified(False)
+        self._apply_lock()
+
+    def _on_cancel(self) -> None:
+        self._lock()
+        self.message_label.setText(t("units.locked_note"))
+
+    # ------------------------------------------------------------------ apply
+
+    def collect_changes(self) -> tuple[dict[int, float], str]:
+        """``(changes, problem)`` from the typed values; a problem means nothing is applied."""
+        changes: dict[int, float] = {}
+        for row in self._rows:
+            edit = self._edits.get(row.role)
+            if edit is None or row.axis < 0:
+                continue
+            try:
+                value = float(edit.text().strip())
+            except ValueError:
+                return {}, t("units.invalid", role=t(_ROLE_KEYS.get(row.role, row.role)))
+            if not math.isfinite(value) or value <= 0:
+                return {}, t("units.invalid", role=t(_ROLE_KEYS.get(row.role, row.role)))
+            if not math.isclose(value, row.expected, rel_tol=1e-9, abs_tol=0.0):
+                changes[row.axis] = value
+        return changes, ""
+
+    def _on_apply(self) -> None:
+        changes, problem = self.collect_changes()
+        if problem:
+            self.message_label.setText(problem)
+            return
+        if not changes:
+            self._lock()
+            self.message_label.setText(t("units.no_change"))
+            return
+        if not self._confirm(changes):
+            return
+        self._lock()
+        self.message_label.setText(t("units.applied", count=len(changes)))
+        self.unitsApplied.emit(dict(changes))
+
+    def _confirm(self, changes: dict[int, float]) -> bool:
+        by_axis = {row.axis: row for row in self._rows if row.axis >= 0}
+        lines = []
+        off_calibration = []
+        for axis, value in sorted(changes.items()):
+            row = by_axis.get(axis)
+            role = t(_ROLE_KEYS.get(row.role, row.role)) if row else "?"
+            lines.append(
+                t("units.change_line", role=role, axis=axis, old=_g(row.expected if row else None, 9), new=_g(value, 9))
+            )
+            if (
+                row is not None
+                and row.kind == "rotary"
+                and axis in ROTARY_UNITS_PER_90_DEG
+                and not math.isclose(value, ROTARY_CALIBRATION_UNITS, rel_tol=1e-7, abs_tol=0.0)
+            ):
+                off_calibration.append(role)
+        body = t("units.confirm_body", changes="\n".join(lines))
+        if off_calibration:
+            body += "\n\n" + t(
+                "units.confirm_rotary",
+                roles=", ".join(off_calibration),
+                cal=_g(ROTARY_CALIBRATION_UNITS),
+            )
+        answer = QMessageBox.question(
+            self,
+            t("units.confirm_title"),
+            body,
+            QMessageBox.StandardButton.Yes | QMessageBox.StandardButton.No,
+            QMessageBox.StandardButton.No,
+        )
+        return answer == QMessageBox.StandardButton.Yes
+
+    # ----------------------------------------------------------- translations
+
+    def retranslate(self) -> None:
+        self.hint_label.setText(t("units.hint"))
+        self.modify_button.setText(t("units.modify"))
+        self.apply_button.setText(t("units.apply"))
+        self.cancel_button.setText(t("units.cancel"))
+        self.table.setHorizontalHeaderLabels([t(key) for key in COLUMNS])
+        rotary = "；".join(
+            t("units.rotary_item", axis=axis, units=_g(value, 9))
+            for axis, value in sorted(ROTARY_UNITS_PER_90_DEG.items())
+        )
+        self.constants_label.setText(
+            t(
+                "units.constants",
+                ppm=_g(PULSES_PER_MM, 9),
+                rotary=rotary,
+                cal=_g(ROTARY_CALIBRATION_UNITS),
+            )
+        )
+        if not self.message_label.text():
+            self.message_label.setText(t("units.locked_note"))
+        for index, row in enumerate(self._rows[: self.table.rowCount()]):
+            self._render_row(index, row)
+        self._render_summary()
+        self._apply_lock()
diff --git a/apps/autocal/src/orisys_autocal/ui/window.py b/apps/autocal/src/orisys_autocal/ui/window.py
index 9113777..6d1203a 100644
--- a/apps/autocal/src/orisys_autocal/ui/window.py
+++ b/apps/autocal/src/orisys_autocal/ui/window.py
@@ -46,6 +46,7 @@ from ..motion.pose_move import (
     press_targets,
 )
 from ..motion.service import clamp_bas_task
+from ..motion.unit_report import build_unit_rows
 from ..motion.units import DEFAULT_UNITS, user_units_to_deg, user_units_to_mm
 from ..preferences import load_preferences, save_preferences
 from ..sensor import (
@@ -367,6 +368,8 @@ class AutoCalMainWindow(QMainWindow):
         self.axis_panel.moveRelRequested.connect(self._on_move_rel)
         self.axis_panel.homeRequested.connect(self._on_home)
         self.axis_panel.clearAlarmRequested.connect(self._on_clear_alarm)
+        self.axis_panel.unitsRequested.connect(lambda: self._show_device_setup("units"))
+        self.device_setup.units_page.unitsApplied.connect(self._on_units_applied)
         self.bus_data_panel.sdoReadRequested.connect(self._on_sdo_read)
         self.bus_data_panel.sdoWriteRequested.connect(self._on_sdo_write)
         self.bus_data_panel.rtexReadRequested.connect(self._on_rtex_read)
@@ -423,6 +426,28 @@ class AutoCalMainWindow(QMainWindow):
         problem = self.poller.service.roles_problem()
         if problem:
             self.finger_panel.set_move_status(f"✗ {problem}")
+        self._refresh_unit_report()
+
+    def _refresh_unit_report(self) -> None:
+        """Feed the unit table and the axis page's one-line check from one computation.
+
+        Both read the same rows, so the line on the axis page and the table in the
+        device setup cannot disagree. Nothing here writes to the controller.
+        """
+        panel = getattr(self, "axis_panel", None)
+        if panel is None:
+            return
+        snapshot = panel.snapshot
+        rows = build_unit_rows(
+            self.device_setup.roles_page.roles(), panel.expected_units, snapshot
+        )
+        self.device_setup.units_page.set_rows(rows, snapshot.connected)
+        panel.set_unit_rows(rows, snapshot.connected)
+
+    def _on_units_applied(self, changes: dict) -> None:
+        """Confirmed unit changes go out through the ordinary axis-parameter path."""
+        self.axis_panel.apply_units(changes)
+        self._refresh_unit_report()
 
     def _capture_bus_problem(self) -> str:
         """Why the capture page's bus check fails, or ``""`` when it passes.
@@ -942,6 +967,7 @@ class AutoCalMainWindow(QMainWindow):
         self.bus_data_panel.set_connected(snapshot.connected)
         self.bus_data_panel.set_bus_type(snapshot.bus.bus_type)
         self.axis_panel.update_snapshot(snapshot)
+        self._refresh_unit_report()
         self.axis_readout.update_snapshot(snapshot)
         # Progress the pose move. It waits on the axis readings in this same
         # snapshot, so it costs the poll nothing extra and cannot run ahead of the
diff --git a/apps/autocal/tests/test_axis_events.py b/apps/autocal/tests/test_axis_events.py
new file mode 100644
index 0000000..d93a2cf
--- /dev/null
+++ b/apps/autocal/tests/test_axis_events.py
@@ -0,0 +1,95 @@
+"""The axis event log: only changes, a baseline on first sight, nothing across a gap."""
+
+from __future__ import annotations
+
+from orisys_autocal.motion import AxisState, Snapshot
+from orisys_autocal.motion import events as ev
+from orisys_autocal.motion.models import AxisStatusBits
+from orisys_autocal.motion.events import AxisEventTracker
+
+
+def _axis(axis=0, *, alarm=False, enabled=True, read_ok=True, homing=False, home_status=0, units=10.0, error=""):
+    raw = (512 if alarm else 0) | (64 if homing else 0)
+    return AxisState(
+        axis=axis,
+        enabled=enabled,
+        units=units,
+        status=AxisStatusBits(raw),
+        home_status=home_status,
+        read_ok=read_ok,
+        error=error,
+    )
+
+
+def _snap(*axes, connected=True) -> Snapshot:
+    return Snapshot(connected=connected, axes=tuple(axes))
+
+
+def _kinds(events):
+    return [(event.axis, event.kind) for event in events]
+
+
+def test_the_first_poll_is_a_baseline_and_a_steady_state_is_silent():
+    tracker = AxisEventTracker(clock=lambda: 1.0)
+    assert tracker.update(_snap(_axis(0), _axis(1))) == []
+    assert tracker.update(_snap(_axis(0), _axis(1))) == []
+    assert tracker.events == []
+
+
+def test_an_alarm_that_is_already_up_when_first_seen_is_reported():
+    tracker = AxisEventTracker()
+    assert _kinds(tracker.update(_snap(_axis(2, alarm=True)))) == [(2, ev.ALARM_ON)]
+
+
+def test_alarm_enable_and_homing_edges_are_reported_once():
+    tracker = AxisEventTracker()
+    tracker.update(_snap(_axis(0, enabled=False)))
+    assert _kinds(tracker.update(_snap(_axis(0, enabled=True)))) == [(0, ev.ENABLED)]
+    assert _kinds(tracker.update(_snap(_axis(0, alarm=True)))) == [(0, ev.ALARM_ON)]
+    assert tracker.update(_snap(_axis(0, alarm=True))) == []
+    assert _kinds(tracker.update(_snap(_axis(0)))) == [(0, ev.ALARM_OFF)]
+    assert _kinds(tracker.update(_snap(_axis(0, homing=True)))) == [(0, ev.HOME_STARTED)]
+    assert _kinds(tracker.update(_snap(_axis(0, home_status=1)))) == [(0, ev.HOME_DONE)]
+    tracker.update(_snap(_axis(0, homing=True)))
+    assert _kinds(tracker.update(_snap(_axis(0, home_status=0)))) == [(0, ev.HOME_INCOMPLETE)]
+
+
+def test_a_read_failure_and_its_recovery_are_reported():
+    tracker = AxisEventTracker()
+    tracker.update(_snap(_axis(1)))
+    failed = tracker.update(_snap(_axis(1, read_ok=False, error="timeout")))
+    assert [(e.axis, e.kind, e.detail) for e in failed] == [(1, ev.READ_FAILED, "timeout")]
+    assert tracker.update(_snap(_axis(1, read_ok=False, error="timeout"))) == []
+    assert _kinds(tracker.update(_snap(_axis(1)))) == [(1, ev.READ_OK)]
+
+
+def test_a_gap_in_the_connection_resets_the_baseline():
+    tracker = AxisEventTracker()
+    tracker.update(_snap(_axis(0)))
+    assert _kinds(tracker.update(_snap(connected=False))) == [(ev.NO_AXIS, ev.DISCONNECTED)]
+    # Back again with the axis alarmed: the connection edge, then the alarm as a
+    # first sight; nothing is compared with a state from before the gap.
+    back = tracker.update(_snap(_axis(0, alarm=True)))
+    assert _kinds(back) == [(ev.NO_AXIS, ev.CONNECTED), (0, ev.ALARM_ON)]
+
+
+def test_units_disagreeing_with_the_configuration_is_an_event_both_ways():
+    tracker = AxisEventTracker()
+    expected = {0: 10.0}
+    assert tracker.update(_snap(_axis(0, units=10.0)), expected) == []
+    mismatch = tracker.update(_snap(_axis(0, units=5.0)), expected)
+    assert [(e.kind, e.detail) for e in mismatch] == [(ev.UNITS_MISMATCH, "10|5")]
+    assert tracker.update(_snap(_axis(0, units=5.0)), expected) == []
+    assert _kinds(tracker.update(_snap(_axis(0, units=10.0)), expected)) == [(0, ev.UNITS_OK)]
+    # With nothing to compare against no verdict is invented.
+    assert AxisEventTracker().update(_snap(_axis(0, units=5.0))) == []
+
+
+def test_the_log_is_bounded_and_can_be_cleared():
+    tracker = AxisEventTracker(limit=3)
+    tracker.update(_snap(_axis(0)))
+    for index in range(10):
+        tracker.update(_snap(_axis(0, alarm=bool(index % 2 == 0))))
+    assert len(tracker.events) == 3
+    tracker.clear()
+    assert tracker.events == []
diff --git a/apps/autocal/tests/test_device_setup.py b/apps/autocal/tests/test_device_setup.py
index ceff032..340ba69 100644
--- a/apps/autocal/tests/test_device_setup.py
+++ b/apps/autocal/tests/test_device_setup.py
@@ -180,7 +180,7 @@ def test_the_axis_mapping_page_holds_the_mapping_and_refuses_duplicates(make_win
     window = make_window()
     try:
         dialog = window.device_setup
-        assert dialog.tabs.count() == 4
+        assert dialog.tabs.count() == 5
         page = dialog.roles_page
         assert page.roles() == DEFAULT_AXIS_ROLES
         assert page.problem() == ""
diff --git a/apps/autocal/tests/test_unit_report.py b/apps/autocal/tests/test_unit_report.py
new file mode 100644
index 0000000..88921ac
--- /dev/null
+++ b/apps/autocal/tests/test_unit_report.py
@@ -0,0 +1,110 @@
+"""The unit table: what is configured, what the controller reads, and the verdict."""
+
+from __future__ import annotations
+
+import math
+
+import pytest
+from orisys_autocal.motion import AxisState, Snapshot
+from orisys_autocal.motion.models import AxisStatusBits
+from orisys_autocal.motion.service import DEFAULT_AXIS_ROLES
+from orisys_autocal.motion.unit_report import (
+    INVALID,
+    MISMATCH,
+    OK,
+    UNCALIBRATED,
+    UNMAPPED,
+    UNREAD,
+    build_unit_rows,
+    summarise,
+)
+
+ROLES = dict(DEFAULT_AXIS_ROLES)  # x0 y1 yaw2 pitch3 z4
+
+
+def _snapshot(units: dict[int, float], *, connected: bool = True) -> Snapshot:
+    axes = tuple(
+        AxisState(axis=axis, units=value, status=AxisStatusBits(0), read_ok=True)
+        for axis, value in units.items()
+    )
+    return Snapshot(connected=connected, axes=axes)
+
+
+def _rows(expected: float | dict[int, float], observed: dict[int, float] | None, **kw):
+    def expected_of(axis: int) -> float:
+        return expected[axis] if isinstance(expected, dict) else expected
+
+    snapshot = None if observed is None else _snapshot(observed, **kw)
+    return {row.role: row for row in build_unit_rows(ROLES, expected_of, snapshot)}
+
+
+def test_a_matching_platform_is_all_ok_with_the_bench_scales():
+    rows = _rows(10.0, {axis: 10.0 for axis in range(5)})
+    assert [row.status for row in rows.values()] == [OK] * 5
+    # Linear: 5000 pulses per millimetre and a pulse equivalent of 10.
+    assert rows["x"].per_unit == pytest.approx(10.0 / 5000.0)
+    assert rows["x"].per_mm == pytest.approx(500.0)
+    assert rows["z"].kind == "linear"
+    # Rotary: 12500 and 29500 user units per quarter turn.
+    assert rows["yaw"].axis == 2
+    assert rows["yaw"].per_mm == pytest.approx(12500.0 / 90.0)
+    assert rows["pitch"].per_mm == pytest.approx(29500.0 / 90.0)
+    assert rows["yaw"].per_unit == pytest.approx(90.0 / 12500.0)
+    assert [row.role for row in rows.values()] == ["x", "y", "z", "yaw", "pitch"]
+
+
+def test_no_connection_or_no_readback_is_unread_not_fine():
+    assert {row.status for row in _rows(10.0, None).values()} == {UNREAD}
+    offline = _rows(10.0, {axis: 10.0 for axis in range(5)}, connected=False)
+    assert {row.status for row in offline.values()} == {UNREAD}
+    assert all(row.observed is None for row in offline.values())
+
+
+def test_a_controller_that_disagrees_is_a_mismatch_for_that_axis_only():
+    observed = {axis: 10.0 for axis in range(5)}
+    observed[1] = 5.0
+    rows = _rows(10.0, observed)
+    assert rows["y"].status == MISMATCH
+    assert rows["y"].observed == 5.0
+    assert [row.status for role, row in rows.items() if role != "y"] == [OK] * 4
+    good, total, problems = summarise(list(rows.values()))
+    assert (good, total, [row.role for row in problems]) == (4, 5, ["y"])
+
+
+def test_rotary_axes_are_not_calibrated_away_from_the_bench_equivalent():
+    # Same on both sides, so the controller agrees, but there is no angle scale.
+    rows = _rows({0: 10.0, 1: 10.0, 2: 5.0, 3: 10.0, 4: 10.0}, {0: 10.0, 1: 10.0, 2: 5.0, 3: 10.0, 4: 10.0})
+    assert rows["yaw"].status == UNCALIBRATED
+    assert math.isnan(rows["yaw"].per_unit) and math.isnan(rows["yaw"].per_mm)
+    # A linear axis rescales freely: the scale follows the equivalent.
+    linear = _rows({0: 5.0, 1: 10.0, 2: 10.0, 3: 10.0, 4: 10.0}, {0: 5.0, 1: 10.0, 2: 10.0, 3: 10.0, 4: 10.0})
+    assert linear["x"].status == OK
+    assert linear["x"].per_mm == pytest.approx(1000.0)
+
+
+@pytest.mark.parametrize("bad", [0.0, -1.0, math.nan, math.inf])
+def test_an_unusable_configured_value_is_invalid(bad):
+    rows = _rows(bad, {axis: 10.0 for axis in range(5)})
+    # inf is not finite either; every row is refused, none shows a made-up scale.
+    assert {row.status for row in rows.values()} == {INVALID}
+    assert all(math.isnan(row.per_unit) for row in rows.values())
+
+
+def test_a_role_without_a_drive_is_unmapped():
+    roles = {key: value for key, value in ROLES.items() if key != "z"}
+    rows = {r.role: r for r in build_unit_rows(roles, lambda axis: 10.0, _snapshot({0: 10.0}))}
+    assert rows["z"].status == UNMAPPED
+    assert rows["z"].axis == -1
+
+
+def test_the_verdict_agrees_with_the_motion_guard():
+    """The page must never say fine where :meth:`MotionService.units_problem` refuses."""
+    from orisys_autocal.motion.service import MotionService
+
+    service = MotionService()
+    observed = {axis: 10.0 for axis in range(5)}
+    snapshot = _snapshot(observed)
+    service._last_axes = {state.axis: state for state in snapshot.axes}  # noqa: SLF001
+    rows = {r.role: r for r in build_unit_rows(service.axis_roles, lambda a: service.params(a).units, snapshot)}
+    for role, row in rows.items():
+        assert (service.units_problem(role, row.axis) == "") == row.ok, role
diff --git a/apps/autocal/tests/test_units_page.py b/apps/autocal/tests/test_units_page.py
new file mode 100644
index 0000000..cd7cea1
--- /dev/null
+++ b/apps/autocal/tests/test_units_page.py
@@ -0,0 +1,213 @@
+"""The units page (locked by default) and the axis page's alarm and event log.
+
+Interface tests: they drive the widgets an operator uses. The controller is never
+reached; snapshots are built by hand, and ``QMessageBox.question`` is answered by the
+test, so nothing here opens a dialog.
+"""
+
+from __future__ import annotations
+
+import pytest
+from orisys_app_shared.i18n import t
+from orisys_autocal.motion import AxisState, Snapshot
+from orisys_autocal.motion.models import AxisStatusBits
+from orisys_autocal.motion.service import DEFAULT_AXIS_ROLES
+from orisys_autocal.motion.unit_report import build_unit_rows
+from PySide6.QtWidgets import QMessageBox
+
+ROLES = dict(DEFAULT_AXIS_ROLES)
+
+
+def _snapshot(*, connected: bool = True, alarm_axis: int | None = None, units: float = 10.0):
+    axes = tuple(
+        AxisState(
+            axis=axis,
+            enabled=True,
+            units=units,
+            status=AxisStatusBits(512 if axis == alarm_axis else 0),
+            read_ok=True,
+        )
+        for axis in range(5)
+    )
+    return Snapshot(connected=connected, axes=axes)
+
+
+def _rows(connected: bool = True, expected: float = 10.0):
+    return build_unit_rows(ROLES, lambda axis: expected, _snapshot(connected=connected))
+
+
+def _answer(monkeypatch, button) -> list[str]:
+    """Answer the confirmation with ``button`` and record what it asked."""
+    asked: list[str] = []
+
+    def question(parent, title, body, *args, **kwargs):
+        asked.append(body)
+        return button
+
+    monkeypatch.setattr(QMessageBox, "question", question)
+    return asked
+
+
+def test_the_page_is_locked_until_the_operator_presses_modify(make_window):
+    window = make_window()
+    page = window.device_setup.units_page
+    page.set_rows(_rows(connected=False), False)
+    assert page.locked
+    assert all(edit.isReadOnly() for edit in page._edits.values())  # noqa: SLF001
+    # Nothing to change on a machine that is not connected.
+    assert not page.modify_button.isEnabled()
+
+    page.set_rows(_rows(), True)
+    assert page.modify_button.isEnabled()
+    page.modify_button.click()
+    assert not page.locked
+    assert not any(edit.isReadOnly() for edit in page._edits.values())  # noqa: SLF001
+    assert page.apply_button.isEnabled()
+    window.close()
+
+
+def test_a_confirmed_change_is_emitted_and_the_page_locks_again(make_window, monkeypatch):
+    window = make_window()
+    page = window.device_setup.units_page
+    page.set_rows(_rows(), True)
+    emitted: list[dict] = []
+    page.unitsApplied.connect(emitted.append)
+    asked = _answer(monkeypatch, QMessageBox.StandardButton.Yes)
+
+    page.modify_button.click()
+    page._edits["x"].setText("5")  # noqa: SLF001
+    page.apply_button.click()
+
+    assert emitted == [{0: 5.0}]
+    assert page.locked
+    assert "5" in asked[0] and "10" in asked[0]
+    window.close()
+
+
+def test_declining_the_confirmation_changes_nothing(make_window, monkeypatch):
+    window = make_window()
+    page = window.device_setup.units_page
+    page.set_rows(_rows(), True)
+    emitted: list[dict] = []
+    page.unitsApplied.connect(emitted.append)
+    _answer(monkeypatch, QMessageBox.StandardButton.No)
+
+    page.modify_button.click()
+    page._edits["y"].setText("20")  # noqa: SLF001
+    page.apply_button.click()
+
+    assert emitted == []
+    assert not page.locked  # still the operator's to finish or cancel
+    page.cancel_button.click()
+    assert page.locked
+    assert page._edits["y"].text() == "10"  # noqa: SLF001
+    window.close()
+
+
+def test_a_rotary_value_off_the_calibration_is_warned_about(make_window, monkeypatch):
+    window = make_window()
+    page = window.device_setup.units_page
+    page.set_rows(_rows(), True)
+    asked = _answer(monkeypatch, QMessageBox.StandardButton.No)
+
+    page.modify_button.click()
+    page._edits["yaw"].setText("5")  # noqa: SLF001
+    page.apply_button.click()
+
+    assert t("units.confirm_rotary", roles=t("setup.role_yaw"), cal="10") in asked[0]
+    window.close()
+
+
+@pytest.mark.parametrize("bad", ["", "abc", "0", "-3", "nan", "inf"])
+def test_an_unusable_value_is_refused_before_any_question(make_window, monkeypatch, bad):
+    window = make_window()
+    page = window.device_setup.units_page
+    page.set_rows(_rows(), True)
+    emitted: list[dict] = []
+    page.unitsApplied.connect(emitted.append)
+    asked = _answer(monkeypatch, QMessageBox.StandardButton.Yes)
+
+    page.modify_button.click()
+    page._edits["z"].setText(bad)  # noqa: SLF001
+    page.apply_button.click()
+
+    assert emitted == [] and asked == []
+    assert t("units.invalid", role=t("setup.role_z")) == page.message_label.text()
+    window.close()
+
+
+def test_applying_without_a_change_just_locks(make_window, monkeypatch):
+    window = make_window()
+    page = window.device_setup.units_page
+    page.set_rows(_rows(), True)
+    emitted: list[dict] = []
+    page.unitsApplied.connect(emitted.append)
+    asked = _answer(monkeypatch, QMessageBox.StandardButton.Yes)
+
+    page.modify_button.click()
+    page.apply_button.click()
+
+    assert emitted == [] and asked == []
+    assert page.locked
+    window.close()
+
+
+def test_a_changed_axis_mapping_drops_an_open_edit(make_window):
+    window = make_window()
+    page = window.device_setup.units_page
+    page.set_rows(_rows(), True)
+    page.modify_button.click()
+    page._edits["x"].setText("5")  # noqa: SLF001
+
+    swapped = dict(ROLES, x=1, y=0)
+    page.set_rows(build_unit_rows(swapped, lambda axis: 10.0, _snapshot()), True)
+
+    assert page.locked
+    assert page._edits["x"].text() == "10"  # noqa: SLF001
+    window.close()
+
+
+def test_the_units_tab_and_the_axis_page_are_wired(make_window, monkeypatch):
+    window = make_window()
+    monkeypatch.setattr(window.poller, "submit", lambda *args, **kwargs: 0)
+    panel = window.axis_panel
+    # The always-live form no longer takes a pulse equivalent.
+    assert panel.units_edit.isReadOnly()
+    # The button on the axis page opens the units tab.
+    panel.unitsRequested.emit()
+    assert window.device_setup.current_tab() == "units"
+    # A confirmed change goes out as an ordinary axis-parameter apply.
+    applied: list[tuple] = []
+    panel.paramsApplied.connect(lambda axis, params: applied.append((axis, params.units)))
+    window.device_setup.units_page.unitsApplied.emit({1: 5.0})
+    assert applied == [(1, 5.0)]
+    assert panel.expected_units(1) == 5.0
+    window.close()
+
+
+def test_the_axis_page_logs_alarms_and_can_clear_the_log(make_window):
+    window = make_window()
+    panel = window.axis_panel
+    panel.update_snapshot(_snapshot())
+    assert panel.event_log.count() == 0
+    assert not panel.events_empty.isHidden()
+
+    panel.update_snapshot(_snapshot(alarm_axis=2))
+    assert panel.event_log.count() == 1
+    assert t("axes.ev_alarm_on", axis=2) in panel.event_log.item(0).text()
+    assert panel.events_empty.isHidden()
+
+    panel.clear_events_button.click()
+    assert panel.event_log.count() == 0
+    window.close()
+
+
+def test_a_unit_mismatch_reaches_the_axis_page_summary(make_window):
+    window = make_window()
+    window.axis_panel.update_snapshot(_snapshot(units=5.0))
+    window._refresh_unit_report()  # noqa: SLF001 - the window does this on every poll
+    assert t("units.summary_bad", bad=5, total=5) == window.axis_panel.units_chip.text()
+    window.axis_panel.update_snapshot(_snapshot(units=10.0))
+    window._refresh_unit_report()  # noqa: SLF001
+    assert t("units.summary_ok", total=5) == window.axis_panel.units_chip.text()
+    window.close()