DAQ: fix to handle automated raster parameters

daq/src/aaredaq/daq.py

@@ -1212,30 +1212,45 @@ class AareDAQ:
 
         params = SimpleScanParameters()
 
-        if (exp := getattr(aaredb_params, 'exposure', 0.04)) is not None:
+        # Exposure
+        exp = getattr(aaredb_params, 'exposure', None)
+        if exp is not None:
             params.exp_time_s = exp
+        else:
+            params.exp_time_s = 0.04  # Default
 
-        if (trans := getattr(aaredb_params, 'transmission', 100)) is not None:
+        # Transmission
+        trans = getattr(aaredb_params, 'transmission', None)
+        if trans is not None:
             logger.debug(f"transmission: {trans}")
             params.transmission = trans / 100.0 if trans > 1.0 else trans
-
-        if (res := getattr(aaredb_params, 'targetresolution', 1.42)) is not None:
-            logger.debug(f"resolution: {res}")
-            logger.debug(f"dtz: {self.diffraction_geometry.calc_dtz_mm(res)}")
-            params.dtz = self.diffraction_geometry.calc_dtz_mm(res)
-
-        if res <= 1.5:
-            params.exp_time_s = 0.02
-        elif 1.5 < res <= 3.0:
-            params.exp_time_s = 0.04
         else:
-            params.exp_time_s = 0.08
+            params.transmission = 1.0  # Default
 
-        logger.debug(f"res expected {res} using {params.exp_time_s} exp time")
+        # Resolution and DTZ
+        res = getattr(aaredb_params, 'targetresolution', None)
+        if res is not None:
+            logger.debug(f"resolution: {res}")
+            try:
+                params.dtz = self.diffraction_geometry.calc_dtz_mm(res)
+                logger.debug(f"dtz: {params.dtz}")
+            except Exception as e:
+                logger.error(f"Failed to calculate dtz for resolution {res}: {e}")
+                params.dtz = 150  # Fallback default
+
+            # Adjust exposure time based on resolution
+            if res <= 1.5:
+                params.exp_time_s = 0.02
+            elif 1.5 < res <= 3.0:
+                params.exp_time_s = 0.04
+            else:
+                params.exp_time_s = 0.08
+        else:
+            params.dtz = 150
+            params.exp_time_s = 0.04
 
         return params
 
-
     def get_collection_params(self, prefer_smart: bool = False) -> tuple[SimpleScanParameters, str]:
         spreadsheet_params = self.spreadsheet_params()
         logger.debug(f"spreadsheet_params: {spreadsheet_params}")