Groan. It is tolist() and not to_list().

SDP/SDP/SDP.py

@@ -286,7 +286,7 @@ class SDP(Device):
     @fault_on_error
     def write_fpga_mask_RW(self, value):
         """Return the fpga_mask_RW attribute."""
-        self.attribute_mapping["fpga_mask_RW"].set_value(value.to_list())
+        self.attribute_mapping["fpga_mask_RW"].set_value(value.tolist())
         _fpga_mask_RW = value
         return
 
@@ -307,7 +307,7 @@ class SDP(Device):
     @fault_on_error
     def write_fpga_scrap_RW(self, value):
         """Return the fpga_scrap_RW attribute."""
-        self.attribute_mapping["fpga_scrap_RW"].set_value(value.to_list())
+        self.attribute_mapping["fpga_scrap_RW"].set_value(value.tolist())
         _fpga_scrap_RW = value
         return