diff --git a/SDP/SDP/SDP.py b/SDP/SDP/SDP.py
index 76e6616ff8ba70603ca869d75b42ecd10cb56736..1a2fed41d07085346d9f6114917259c009be90ba 100644
--- a/SDP/SDP/SDP.py
+++ b/SDP/SDP/SDP.py
@@ -303,7 +303,7 @@ class SDP(Device):
     def write_fpga_mask_RW(self, value):
         """Return the fpga_mask_RW attribute."""
         self.attribute_mapping["fpga_mask_RW"].set_value(value.tolist())
-        _fpga_mask_RW = value
+        self._fpga_mask_RW = value
         return
 
     @only_when_on
@@ -366,7 +366,7 @@ class SDP(Device):
     def write_fpga_weights_RW(self, value):
         """Return the fpga_weights_RW attribute."""
         self.attribute_mapping["fpga_weights_RW"].set_data_value(opcua.ua.uatypes.Variant(value = value.flatten().tolist(), varianttype=opcua.ua.VariantType.Int16))
-        _fpga_weights_RW = value
+        self._fpga_weights_RW = value
 
     @only_when_on
     @fault_on_error