diff --git a/ADwinProII/ADwin_utils.py b/ADwinProII/ADwin_utils.py
index 6825e3e86d97113da220af235a725056ce0a2582..fa1d2f41eaf3f9d62313bb05577763dec6f206d9 100644
--- a/ADwinProII/ADwin_utils.py
+++ b/ADwinProII/ADwin_utils.py
@@ -103,7 +103,7 @@ def get_channel_from_BLACS_name(BLACS_name):
     return int(channel)
 
 
-def get_ain_traces(h5file, raw_data_name="ADwinAnalogIn_DATA", convert_data=True, device_name="ADwin"):
+def get_ain_traces(h5file, raw_data_name="ADwinAnalogIn_DATA", convert_data=True, device_name="ADwin", write_hdf5 = True):
     """ 
     Split raw (sorted!) data from ADwin analog inputs into aquisitions
     of channels and store the traces for each channel in the h5 file.
@@ -118,8 +118,11 @@ def get_ain_traces(h5file, raw_data_name="ADwinAnalogIn_DATA", convert_data=True
         Set is the input voltage is stored as row value, or converted to volts.
     device_name : str, optional
         Name of the ADwin device.
+    write_hdf5 : bool, optional
+        Decides if the single traces are written to the hdf5 file or returned. 
     """
-    with h5py.File(h5file, 'r+') as f:
+    return_dict = {}
+    with h5py.File(h5file, 'r'+write_hdf5*'+') as f: # open with(out) write permission depending on argument
         group = f["data/traces"]
         if raw_data_name not in group:
             print(f"No raw acquisition data with name '{raw_data_name}' found!")
@@ -154,8 +157,13 @@ def get_ain_traces(h5file, raw_data_name="ADwinAnalogIn_DATA", convert_data=True
             else:
                 times = np.arange(acquisition_times["start_time"][i],acquisition_times["stop_time"][i]) / clock_rate
             # print(times.size,acquisition.size)
-            data = np.rec.fromarrays([times, acquisition], dtype=dtype)
-            group.create_dataset(label, compression = config.compression, data = data)
+            if write_hdf5:
+                data = np.rec.fromarrays([times, acquisition], dtype=dtype)
+                group.create_dataset(label, compression = config.compression, data = data)
+            else:
+                return_dict[label] = times, acquisition
+    if not write_hdf5:
+        return return_dict