diff --git a/csaxs_bec/devices/omny/galil/galil_rio.py b/csaxs_bec/devices/omny/galil/galil_rio.py
index c196b72..ec32564 100644
--- a/csaxs_bec/devices/omny/galil/galil_rio.py
+++ b/csaxs_bec/devices/omny/galil/galil_rio.py
@@ -115,10 +115,10 @@ 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])
-                if 0 <= channel_index < len(values):
+                idx = int(walk.item.attr_name[-1])
+                if 0 <= idx < len(values):
                     old_val = walk.item._readback
-                    new_val = values[channel_index]
+                    new_val = values[idx]
                     timestamp = time.time()
                     walk.item._metadata["timestamp"] = timestamp
                     walk.item._readback = new_val