Moved the default timeout calculation earlier to re-enable multiple t…

…riggers.

src/haven/devices/ion_chamber.py

@@ -303,15 +303,15 @@ async def trigger(self, record_dark_current=False):
         if record_dark_current:
             await self.record_dark_current()
             return
+        # Calculate expected timeout value
+        timeout = await self.default_timeout()
         # Check if we've seen this signal before
         signal = self.mcs.scaler.count
         last_status = self._trigger_statuses.get(signal.source)
         # Previous trigger is still going, so wait for that instead
         if last_status is not None and not last_status.done:
             await last_status
             return
-        # Calculate expected timeout value
-        timeout = await self.default_timeout()
         # Nothing to wait on yet, so trigger the scaler and stash the result
         st = signal.set(True, timeout=timeout)
         self._trigger_statuses[signal.source] = st