Get mirror immediate position

finesse/hardware/data_file_writer.py

@@ -68,8 +68,8 @@ def _get_stepper_motor_angle() -> tuple[float, bool]:
     """Get the current angle of the stepper motor.
 
     This function returns a float indicating the angle in degrees and a boolean
-    indicating whether the motor is currently moving. If an error occurs or the motor is
-    moving, the angle returned will be nan.
+    indicating whether the motor is currently moving. If an error occurs, the angle
+    returned will be nan.
     """
     stepper = get_stepper_motor_instance()
 
@@ -79,10 +79,8 @@ def _get_stepper_motor_angle() -> tuple[float, bool]:
 
     try:
         angle = stepper.angle
-        if angle is None:
-            return (float("nan"), True)
-        else:
-            return (angle, False)
+        is_moving = stepper.is_moving
+        return (angle, is_moving)
     except Exception as error:
         stepper.send_error_message(error)
         return (float("nan"), False)

finesse/hardware/plugins/stepper_motor/st10_controller.py

@@ -335,21 +335,19 @@ def is_moving(self) -> bool:
         return self.status_code & 0x0010 == 0x0010
 
     @property
-    def step(self) -> int | None:
+    def step(self) -> int:
         """The current state of the device's step counter.
 
-        As this can only be requested when the motor is stationary, if the motor is
-        moving then None will be returned.
+        This makes use of the "IP" command, which estimates the immediate position of
+        the motor. If the motor is moving, this is an estimated (calculated trajectory)
+        position. If the motor is stationary, this is the actual position.
 
         Raises:
             SerialException: Error communicating with device
             SerialTimeoutException: Timed out waiting for response from device
             ST10ControllerError: Malformed message received from device
         """
-        if self.is_moving:
-            return None
-
-        step = self._request_value("SP")
+        step = self._request_value("IP")
         try:
             return int(step)
         except ValueError:

finesse/hardware/plugins/stepper_motor/stepper_motor_base.py

@@ -41,12 +41,8 @@ def steps_per_rotation(self) -> int:
 
     @property
     @abstractmethod
-    def step(self) -> int | None:
-        """The current state of the device's step counter.
-
-        As this can only be requested when the motor is stationary, if the motor is
-        moving then None will be returned.
-        """
+    def step(self) -> int:
+        """The current state of the device's step counter."""
 
     @step.setter
     @abstractmethod
@@ -67,20 +63,13 @@ def is_moving(self) -> bool:
         """Whether the motor is currently moving."""
 
     @property
-    def angle(self) -> float | None:
+    def angle(self) -> float:
         """The current angle of the motor in degrees.
 
-        As this can only be requested when the motor is stationary, if the motor is
-        moving then None will be returned.
-
         Returns:
-            The current angle or None if the stepper motor is moving
+            The current angle
         """
-        step = self.step
-        if step is None:
-            return None
-
-        return step * 360.0 / self.steps_per_rotation
+        return self.step * 360.0 / self.steps_per_rotation
 
     def move_to(self, target: float | str) -> None:
         """Move the motor to a specified rotation and send message when complete.

tests/hardware/plugins/stepper_motor/test_st10_controller.py

@@ -240,7 +240,7 @@ def test_write_check(dev: ST10Controller) -> None:
             if response.startswith(f"{name}=")
             else pytest.raises(ST10ControllerError),
         )
-        for name in ["hello", "IS", "SP"]
+        for name in ["hello", "IS", "IP"]
         for value in ["", "value", "123"]
         for response in [f"{name}={value}", value, "%", "*", "?4"]
     ],
@@ -357,41 +357,22 @@ def test_is_moving(
 @pytest.mark.parametrize(
     "step,response,raises",
     chain(
-        [(step, f"SP={step}", does_not_raise()) for step in range(0, 250, 50)],
-        [(4, "SP=hello", pytest.raises(ST10ControllerError))],
+        [(step, f"IP={step}", does_not_raise()) for step in range(0, 250, 50)],
+        [(4, "IP=hello", pytest.raises(ST10ControllerError))],
     ),
 )
-@patch(
-    "finesse.hardware.plugins.stepper_motor.st10_controller.ST10Controller.is_moving",
-    new_callable=PropertyMock,
-)
-def test_get_step_not_moving(
-    is_moving_mock: PropertyMock,
+def test_get_step(
     step: int,
     response: str,
     raises: Any,
     dev: ST10Controller,
 ) -> None:
-    """Test getting the step property when the motor is stationary."""
-    is_moving_mock.return_value = False
+    """Test getting the step property."""
     with read_mock(dev, response):
         with raises:
             assert dev.step == step
 
 
-@patch(
-    "finesse.hardware.plugins.stepper_motor.st10_controller.ST10Controller.is_moving",
-    new_callable=PropertyMock,
-)
-def test_get_step_moving(
-    is_moving_mock: PropertyMock,
-    dev: ST10Controller,
-) -> None:
-    """Test getting the step property when the motor is moving."""
-    is_moving_mock.return_value = True
-    assert dev.step is None
-
-
 @pytest.mark.parametrize("step", range(0, 40, 7))
 def test_set_step(dev: ST10Controller, step: int) -> None:
     """Test setting the step property."""

tests/hardware/plugins/stepper_motor/test_stepper_motor_base.py

@@ -22,7 +22,7 @@ def is_moving(self) -> bool:
         return False
 
     @property
-    def step(self) -> int | None:
+    def step(self) -> int:
         return self._step
 
     @step.setter

tests/hardware/test_data_file_writer.py

@@ -129,6 +129,7 @@ def test_write(
     """Test the write() method."""
     get_stepper_mock.return_value = stepper = MagicMock()
     stepper.angle = 90.0
+    stepper.is_moving = False
     get_tc_mock.return_value = hot_bb = MagicMock()
     hot_bb.power = 10
 
@@ -144,6 +145,33 @@ def test_write(
     sendmsg_mock.assert_called_once_with("data_file.writing")
 
 
+@patch("finesse.hardware.data_file_writer.get_temperature_controller_instance")
+@patch("finesse.hardware.data_file_writer.get_stepper_motor_instance")
+def test_write_moving(
+    get_stepper_mock: Mock,
+    get_tc_mock: Mock,
+    writer: DataFileWriter,
+    sendmsg_mock: Mock,
+) -> None:
+    """Test the write() method when the stepper motor is moving."""
+    get_stepper_mock.return_value = stepper = MagicMock()
+    stepper.angle = 95.0
+    stepper.is_moving = True
+    get_tc_mock.return_value = hot_bb = MagicMock()
+    hot_bb.power = 10
+
+    time = datetime(2023, 4, 14, 0, 1, 0)  # one minute past midnight
+    data = [Decimal(i) for i in range(3)]
+
+    writer._writer = MagicMock()
+    writer.write(time, data)
+    writer._writer.writerow.assert_called_once_with(
+        ("20230414", "00:01:00", *data, 60, 95.0, True, 10)
+    )
+
+    sendmsg_mock.assert_called_once_with("data_file.writing")
+
+
 @patch("finesse.hardware.data_file_writer.get_temperature_controller_instance")
 @patch("finesse.hardware.data_file_writer.get_stepper_motor_instance")
 def test_write_error(
@@ -155,6 +183,7 @@ def test_write_error(
     """Test the write() method when an error occurs."""
     get_stepper_mock.return_value = stepper = MagicMock()
     stepper.angle = 90.0
+    stepper.angle = False
     get_tc_mock.return_value = hot_bb = MagicMock()
     hot_bb.power = 10