(#1517) Make output pulse width equal to exposure time to ensure pcap…

… capture correctly triggered

src/hyperion/device_setup_plans/setup_panda.py

@@ -21,7 +21,6 @@
 
 MM_TO_ENCODER_COUNTS = 200000
 GENERAL_TIMEOUT = 60
-DETECTOR_TRIGGER_WIDTH = 1e-4
 TICKS_PER_MS = 1000  # Panda sequencer prescaler will be set to us
 
 
@@ -165,9 +164,7 @@ def setup_panda_for_flyscan(
         wait=True,
     )
 
-    yield from bps.abs_set(
-        panda.pulse[1].width, DETECTOR_TRIGGER_WIDTH, group="panda-config"
-    )
+    yield from bps.abs_set(panda.pulse[1].width, exposure_time_s, group="panda-config")
 
     exposure_distance_mm = sample_velocity_mm_per_s * exposure_time_s
 

tests/unit_tests/device_setup_plans/test_setup_panda.py

@@ -6,7 +6,7 @@
 import pytest
 from bluesky.plan_stubs import null
 from bluesky.run_engine import RunEngine
-from bluesky.simulators import RunEngineSimulator
+from bluesky.simulators import RunEngineSimulator, assert_message_and_return_remaining
 from dodal.common.types import UpdatingDirectoryProvider
 from dodal.devices.fast_grid_scan import PandAGridScanParams
 from ophyd_async.panda import SeqTrigger
@@ -125,6 +125,13 @@ def test_setup_panda_correctly_configures_table(
         msg for msg in msgs if not msg.kwargs.get("group", "").startswith("load-phase")
     ]
 
+    assert_message_and_return_remaining(
+        msgs,
+        lambda msg: msg.command == "set"
+        and msg.obj.name == "panda-pulse-1-width"
+        and msg.args[0] == exposure_time_s,
+    )
+
     table_msg = [
         msg
         for msg in msgs