feat(run-hour-meter): add getter to read run time in hours

also added valid tests

Signed-off-by: Milad Makdesi <milad@id8-engineering.io>

Author: MiladMakdesi

src/em511/em511.py

@@ -37,6 +37,7 @@ class Em511:
     EM511_REGISTER_PASSWORD = 0x1000
     EM511_REGISTER_KWH_TOT = 0x10
     EM511_REGISTER_KWH_PARTIAL = 0x14
+    EM511_HOUR_COUNTER = 0x2C
     EM511_REGISTER_DEVICE_ID = 0x2000
 
     SCALE_10 = 10
@@ -250,6 +251,21 @@ def kWh_partial(self) -> Decimal:
         value = Decimal(self._unpack(regs, self.EM511_REGISTER_KWH_PARTIAL)) / self.SCALE_10
         return round(value, 1)
 
+    @property
+    def hour_counter(self) -> Decimal:
+        """Run time in hours (h).
+
+        Returns:
+            Decimal: Run time in hours value.
+
+        Raises:
+            ValueError: If input is at max value or above.
+            ModbusException: If failed to read input register.
+        """
+        regs = self._read_input_registers(self.EM511_HOUR_COUNTER, self.INT32_REG_COUNT)
+        value = Decimal(self._unpack(regs, self.EM511_HOUR_COUNTER)) / self.SCALE_100
+        return round(value, 2)
+
     @property
     def password(self) -> int:
         """Password.

src/em511/test_em511.py

@@ -266,6 +266,38 @@ def test_kWh_partial() -> None:
         _ = meter.kWh_partial
 
 
+def test_get_hour_counter() -> None:
+    """Test Get run_hour_meter."""
+    client = MagicMock()
+    mock_result = MagicMock()
+    mock_result.isError.return_value = False
+    meter = Em511(1, client)
+
+    """Test 1: should pass"""
+    mock_result.registers = [0x2904, 0x0000]
+    client.read_input_registers.return_value = mock_result
+    value = meter.hour_counter
+    assert value == Decimal("105.0")
+
+    """Test 2: Should pass."""
+    mock_result.registers = [0x1860, 0x0023]
+    client.read_input_registers.return_value = mock_result
+    value = meter.hour_counter
+    assert value == Decimal("23000.0")
+
+    """Test 3: Should raise exception due to more registers in use than allowed."""
+    mock_result.registers = [0x1860, 0x0023, 0x4244]
+    client.read_input_registers.return_value = mock_result
+    with pytest.raises(ValueError, match="Unexpected register count:"):
+        _ = meter.hour_counter
+
+    """Test 4: Should raise exception if input value exceeds maximum value, display shows 'EEE', 32-bit register."""
+    mock_result.registers = [0xFFFF, 0x7FFF]
+    client.read_input_registers.return_value = mock_result
+    with pytest.raises(ValueError, match="Input overflow EEE for 32-bit register: "):
+        _ = meter.hour_counter
+
+
 def test_get_password() -> None:
     """Test Get password."""
     client = MagicMock()