Channel order on OpenEphys

src/probeinterface/neuropixels_tools.py

@@ -1307,6 +1307,7 @@ def read_openephys(
                 "shank_ids": shank_ids,
                 "elec_ids": elec_ids,
                 "channel_names": channel_names,
+                "channel_order": channel_order,
                 "pt_metadata": pt_metadata,
                 "slot": slot,
                 "port": port,
@@ -1429,6 +1430,9 @@ def read_openephys(
             pt_metadata, probe_part_number, elec_ids, shank_ids=shank_ids, mux_info=mux_info
         )
 
+        if "channel_order" in np_probe_info:
+            probe.set_device_channel_indices(np_probe_info["channel_order"])
+
     if "channel_names" in np_probe_info:
         probe.annotate_contacts(channel_name=np_probe_info["channel_names"])
 

tests/test_io/test_openephys.py

@@ -215,6 +215,28 @@ def test_older_than_06_format():
     assert np.min(ypos) >= 0
 
 
+def test_older_than_06_device_channel_indices():
+    """Test that device_channel_indices correctly map sorted contacts to original XML order."""
+    import xml.etree.ElementTree as ET
+
+    settings_file = data_path / "OE_5_Neuropix-PXI-multi-probe" / "settings.xml"
+    tree = ET.parse(settings_file)
+    root = tree.getroot()
+
+    # Parse the original XML channel order for the first probe
+    np_probe = root.findall(".//NP_PROBE")[0]
+    channels = np_probe.find("CHANNELS")
+    channel_names = list(channels.attrib.keys())
+    channel_ids = np.array([int(ch[2:]) for ch in channel_names])
+    expected_channel_order = np.argsort(channel_ids)
+
+    probe = read_openephys(settings_file, probe_name="100.0")
+
+    # device_channel_indices should map sorted contacts back to original XML positions
+    assert probe.device_channel_indices is not None
+    np.testing.assert_array_equal(probe.device_channel_indices, expected_channel_order)
+
+
 def test_multiple_signal_chains():
     # tests that the probe information can be loaded even if the Neuropix-PXI plugin
     # is not in the first signalchain