Fix triggering order

tomcat_bec/devices/gigafrost/gigafrostcamera.py

@@ -554,6 +554,8 @@ class GigaFrostCamera(PSIDeviceBase, GigaFrostBase):
             d["image_height"] = scan_args["image_height"]
         if "exp_time" in scan_args and scan_args["exp_time"] is not None:
             d["exposure_time_ms"] = scan_args["exp_time"]
+        if "exp_period" in scan_args and scan_args["exp_period"] is not None:
+            d["exposure_period_ms"] = scan_args["exp_period"]
         if "acq_time" in scan_args and scan_args["acq_time"] is not None:
             d["exposure_time_ms"] = scan_args["acq_time"]
         if "acq_period" in scan_args and scan_args["acq_period"] is not None:
@@ -588,14 +590,15 @@ class GigaFrostCamera(PSIDeviceBase, GigaFrostBase):
 
     def on_pre_scan(self) -> DeviceStatus | None:
         """Called right before the scan starts on all devices automatically."""
-        # Switch to acquiring
-        self.arm()
+        # First start the stdDAQ
         if self.backend is not None:
             self.backend.start(
                 file_path=self.file_path.get(),
                 file_prefix=self.file_prefix.get(),
                 num_images=self.num_images.get(),
             )
+        # Then start the camera
+        self.arm()
 
     def on_trigger(self) -> DeviceStatus | None:
         """Called when the device is triggered."""
@@ -618,7 +621,7 @@ class GigaFrostCamera(PSIDeviceBase, GigaFrostBase):
                 wait_time = 0.2 + 0.001 * self.num_exposures.value * max(
                     self.acquire_time.value, self.acquire_period.value
                 )
-                logger.info(f"[{self.name}] Triggering blocks for {wait_time} seconds")
+                logger.info(f"[{self.name}] Triggering set to block for {wait_time} seconds")
                 return DeviceStatus(self, done=True, success=True, settle_time=wait_time)
         else:
             self.soft_trig.set(1).wait()