Added a function for generating NDAttributeParam objects for an xspre…

…ss3 detector.

docs/topic_guides/fluorescence_detectors.rst

@@ -68,6 +68,28 @@ The device can then be retrieved by its name for use in Bluesky plans.
    detectors = haven.beamline.devices.findall(label="fluorescence_detectors")
 
 
+Adding NDAttributes (Xspress3)
+=============================
+
+The EPICS support for an Xspress3 detector provides several additional
+values besides the spectra, many of them useful for dead-time
+correction. These can be saved using the Ophyd-async NDAttribute
+support. Haven includes a function for generating these parameters so
+they can be set on the IOC in a way that allows Tiled to read the
+resulting values from the HDF5 file. This only needs to be done once
+for each detector IOC.
+
+.code-block:: python
+
+    from haven.devices.detectors.xspress import Xspress3Detector, ndattribute_params
+    from ophyd_async.plan_stubs import setup_ndattributes
+
+    # Assuming a 4-element detector
+    detector = Xspress3Detector(...)
+    params = ndattribute_params(device_name=detector.name, elements=range(4))
+    setup_ndattributes(detector, params)
+
+
 Why can't I…
 ############
 

src/haven/devices/detectors/xspress.py

@@ -11,6 +11,7 @@
     TriggerInfo,
 )
 from ophyd_async.epics import adcore
+from ophyd_async.epics.adcore import NDAttributeParam
 from ophyd_async.epics.adcore._utils import ADBaseDataType, convert_ad_dtype_to_np
 from ophyd_async.epics.core import epics_signal_rw, epics_signal_x
 
@@ -126,3 +127,85 @@ async def stage(self) -> None:
             self.drv.erase_on_start.set(False),
             self.drv.erase.trigger(),
         )
+
+
+def ndattribute_params(
+    device_name: str, elements: Sequence[int]
+) -> Sequence[NDAttributeParam]:
+    """Create a set of ndattribute params that can be written to the AD's
+    HDF5 file.
+
+    These parameters can then be used with something like
+    :py:func:`ophyd_async.plan_stubs.setup_ndattributes` to build the
+    XML.
+
+    """
+    params = []
+    for idx in elements:
+        new_params = [
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-deadtime_factor",
+                param="XSP3_CHAN_DTFACTOR",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} DTC Factor",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-deadtime_percent",
+                param="XSP3_CHAN_DTPERCENT",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} DTC Percent",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-event_width",
+                param="XSP3_EVENT_WIDTH",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} Event Width",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-clock_ticks",
+                param="XSP3_CHAN_SCA0",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} ClockTicks",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-reset_ticks",
+                param="XSP3_CHAN_SCA1",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} ResetTicks",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-reset_counts",
+                param="XSP3_CHAN_SCA2",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} ResetCounts",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-all_event",
+                param="XSP3_CHAN_SCA3",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} AllEvent",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-all_good",
+                param="XSP3_CHAN_SCA4",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} AllGood",
+            ),
+            NDAttributeParam(
+                name=f"{device_name}-element{idx}-pileup",
+                param="XSP3_CHAN_SCA7",
+                datatype="DOUBLE",
+                addr=idx,
+                description=f"Chan {idx} Pileup",
+            ),
+        ]
+        params.extend(new_params)
+    return params

src/haven/tests/test_xspress.py

@@ -5,7 +5,7 @@
 from ophyd_async.core import TriggerInfo
 from ophyd_async.testing import get_mock_put, set_mock_value
 
-from haven.devices.detectors.xspress import Xspress3Detector
+from haven.devices.detectors.xspress import Xspress3Detector, ndattribute_params
 
 this_dir = Path(__file__).parent
 
@@ -73,6 +73,13 @@ async def test_deadtime_correction(detector):
     assert not await detector.drv.deadtime_correction.get_value()
 
 
+async def test_ndattribute_params():
+    n_elem = 8
+    n_params = 9
+    params = ndattribute_params(device_name="xsp3", elements=range(n_elem))
+    assert len(params) == n_elem * n_params
+
+
 # -----------------------------------------------------------------------------
 # :author:    Mark Wolfman
 # :email:     [email protected]