diff --git a/csaxs_bec/devices/omny/galil/galil_rio.py b/csaxs_bec/devices/omny/galil/galil_rio.py
index cc97005..c196b72 100644
--- a/csaxs_bec/devices/omny/galil/galil_rio.py
+++ b/csaxs_bec/devices/omny/galil/galil_rio.py
@@ -115,7 +115,7 @@ class GalilRIOSignalRO(GalilSignalRO):
         """
         for walk in self.parent.walk_signals():
             if walk.item.attr_name.startswith("an_ch"):
-                channel_index = int(walk.item.attr_name.split("_")[-1])
+                channel_index = int(walk.item.attr_name.split[-1])
                 if 0 <= channel_index < len(values):
                     old_val = walk.item._readback
                     new_val = values[channel_index]