refactor(timepix): leave detector setup to the IOC and only check it at stage

superxas_bec/devices/timepix/timepix.py

@@ -213,6 +213,14 @@ TIMEPIX_FLY_BACKEND_DEFAULT_REDIS_TOPIC = "public/timepix_fly_backend/raw_data"
 
 TIMEPIX_SCAN_NAME = "timepix_scan"
 
+# detector setup lives in the IOC (autosave); BEC only checks it at stage
+EXPECTED_DETECTOR_SETUP = {
+    "trigger_mode": TRIGGERMODE.INTERNAL,
+    "trigger_source": TRIGGERSOURCE.HDMI1_1,
+    "exposure_mode": EXPOSUREMODE.TIMED,
+}
+EXPECTED_XES_SETUP = {"tdc1_edge": TDCEdge.RISING, "tdc1_output": TDCOuput.ALL_CHANNELS}
+
 # max wait for the images of a lost acquisition before repeating it
 LOST_ACQUISITION_IMAGE_TIMEOUT = 2.0
 
@@ -721,13 +729,25 @@ class Timepix(PSIDeviceBase, TimePixControl):
         """Enable XES specific settings for the TimePix detector."""
         enabled_value = 1 if enabled else 0
         self.cam.tdc1_enable.set(enabled_value).wait(timeout=self._pv_timeout)
-        self.cam.tdc2_enable.set(enabled_value).wait(timeout=self._pv_timeout)
+        # TDC2 is not cabled; TimePixFly would count its edges as periods too
+        self.cam.tdc2_enable.set(0).wait(timeout=self._pv_timeout)
         self.cam.raw_enable.set(enabled_value).wait(timeout=self._pv_timeout)
-        if enabled:
-            self.cam.tdc1_edge.set(TDCEdge.RISING).wait(timeout=self._pv_timeout)
-            self.cam.tdc1_output.set(TDCOuput.ALL_CHANNELS).wait(timeout=self._pv_timeout)
-            self.cam.tdc2_edge.set(TDCEdge.RISING).wait(timeout=self._pv_timeout)
-            self.cam.tdc2_output.set(TDCOuput.ALL_CHANNELS).wait(timeout=self._pv_timeout)
+
+    def _check_detector_setup(self) -> None:
+        """Warn about detector setup PVs, kept in the IOC, that differ from what BEC expects."""
+        expected = dict(EXPECTED_DETECTOR_SETUP)
+        if self.enable_xes:
+            expected.update(EXPECTED_XES_SETUP)
+        wrong = []
+        for attr, value in expected.items():
+            current = getattr(self.cam, attr).get()
+            if current != value:
+                wrong.append(f"{attr}={current} (expected {value.name})")
+        if wrong:
+            logger.warning(
+                f"{self.name}: detector setup differs from what BEC expects: {', '.join(wrong)}. "
+                "These are set in the IOC, not by BEC."
+            )
 
     def wait_for_connection(
         self, all_signals: bool = False, timeout: float | None = None, **kwargs
@@ -745,9 +765,6 @@ class Timepix(PSIDeviceBase, TimePixControl):
         logger.info(f"On Connected of TimePix detector {self.name}...")
         # Prepare TimePix Detector
         self._enable_xes_settings(self.enable_xes)
-        self.cam.trigger_mode.set(TRIGGERMODE.INTERNAL).wait(timeout=self._pv_timeout)
-        self.cam.trigger_source.set(TRIGGERSOURCE.HDMI1_1).wait(timeout=self._pv_timeout)
-        self.cam.exposure_mode.set(EXPOSUREMODE.TIMED).wait(timeout=self._pv_timeout)
         # Reset array counter on connect
         self.cam.array_counter.set(0).wait(timeout=self._pv_timeout)
         # Set image mode to multiple
@@ -830,6 +847,7 @@ class Timepix(PSIDeviceBase, TimePixControl):
         self.cam.acquire_period.set(exp_time).wait(timeout=self._pv_timeout)
         self.cam.num_images.set(burst_images).wait(timeout=self._pv_timeout)
         self.cam.data_source.set(DATASOURCE.IMAGE).wait(timeout=self._pv_timeout)
+        self._check_detector_setup()
 
         # Setup file writing
         self._full_path = get_full_path(scan_msg, name="timepix")

tests/tests_devices/test_timepix.py

@@ -264,16 +264,12 @@ def pixel_map():
 
 def test_timepix_on_connected_configures_signals_and_registers_callback(timepix):
     """Connected hook should configure camera, file writer, and backend callback."""
+    timepix.cam.tdc2_enable.put(1)
     timepix.on_connected()
 
     assert timepix.cam.tdc1_enable.get() == 1
-    assert timepix.cam.tdc2_enable.get() == 1
+    assert timepix.cam.tdc2_enable.get() == 0
     assert timepix.cam.raw_enable.get() == 1
-    assert timepix.cam.tdc1_edge.get() == TDCEdge.RISING
-    assert timepix.cam.tdc1_output.get() == TDCOuput.ALL_CHANNELS
-    assert timepix.cam.trigger_mode.get() == TRIGGERMODE.INTERNAL
-    assert timepix.cam.trigger_source.get() == TRIGGERSOURCE.HDMI1_1
-    assert timepix.cam.exposure_mode.get() == EXPOSUREMODE.TIMED
     assert timepix.cam.array_counter.get() == 0
     assert timepix.hdf.enable.get() == "1"
     assert timepix.hdf.file_write_mode.get() == FILEWRITEMODE.STREAM.value
@@ -909,3 +905,40 @@ def test_timepix_stop_cancels_repetition_of_lost_acquisition(xes_timepix):
     assert timepix.backend.on_trigger_finished.call_count == 1
     assert not timepix._xes_acquisitions
     assert timepix._images_to_skip == 0
+
+
+def test_timepix_on_connected_leaves_detector_setup_to_the_ioc(timepix):
+    """Trigger and TDC edge/output PVs belong to the IOC setup; connecting must not write them."""
+    timepix.cam.trigger_mode.put(TRIGGERMODE.EXTERNAL)
+    timepix.cam.exposure_mode.put(EXPOSUREMODE.TRIGGER_WIDTH)
+    timepix.cam.tdc1_edge.put(TDCEdge.FALLING)
+    timepix.cam.tdc1_output.put(TDCOuput.CHANNEL_0)
+
+    timepix.on_connected()
+
+    assert timepix.cam.trigger_mode.get() == TRIGGERMODE.EXTERNAL
+    assert timepix.cam.exposure_mode.get() == EXPOSUREMODE.TRIGGER_WIDTH
+    assert timepix.cam.tdc1_edge.get() == TDCEdge.FALLING
+    assert timepix.cam.tdc1_output.get() == TDCOuput.CHANNEL_0
+
+
+def test_timepix_check_detector_setup_warns_about_unexpected_values(timepix):
+    """A setup PV that differs from what BEC expects is reported, not overwritten."""
+    timepix._enable_xes = True
+    timepix.cam.trigger_mode.put(TRIGGERMODE.EXTERNAL)
+    timepix.cam.tdc1_edge.put(TDCEdge.FALLING)
+
+    with mock.patch("superxas_bec.devices.timepix.timepix.logger") as logger:
+        timepix._check_detector_setup()
+
+    message = logger.warning.call_args.args[0]
+    assert "trigger_mode" in message and "tdc1_edge" in message
+    assert timepix.cam.trigger_mode.get() == TRIGGERMODE.EXTERNAL
+
+
+def test_timepix_check_detector_setup_is_quiet_when_setup_matches(timepix):
+    """No warning when the IOC setup matches."""
+    timepix._enable_xes = True
+    with mock.patch("superxas_bec.devices.timepix.timepix.logger") as logger:
+        timepix._check_detector_setup()
+    logger.warning.assert_not_called()