diff --git a/LibNoDaveConnectionLibrary/PLCs/S7_xxx/MC7/CallConverter.cs b/LibNoDaveConnectionLibrary/PLCs/S7_xxx/MC7/CallConverter.cs
index 9123449b..20e50859 100644
--- a/LibNoDaveConnectionLibrary/PLCs/S7_xxx/MC7/CallConverter.cs
+++ b/LibNoDaveConnectionLibrary/PLCs/S7_xxx/MC7/CallConverter.cs
@@ -601,7 +601,7 @@ public static void ConvertUCToCall(S7FunctionBlock myFct, S7ProgrammFolder myFld
                                             if (pRow != null) newPar.Value = ((S7DataRow)pRow).StructuredName.Substring(((S7DataRow)pRow).StructuredName.IndexOf('.') + 1);
 
                                         }
-                                        else
+                                        else if (par != null)
                                         {
                                             switch (((S7DataRow)s7DataRow).DataType)
                                             {