SCRIPT
 BEGIN
   EXECUTE IMMEDIATE 
    'CREATE FUNCTION "DecimalValue" ()
     RETURNS DECIMAL(20,2)
     BEGIN
       RETURN 1.2;
     END';
  
   EXECUTE IMMEDIATE 
    'CREATE PROCEDURE "ReturnDecimal" (OUT "Value" DECIMAL(20,2))
     BEGIN
       SET Value = 1.3;
     END';   
 END

 Single statement to test the Function:
   SELECT DecimalValue() 
   FROM Configuration.DataTypes 
   WHERE NAME = 'Char';

 Script to test the Stored Procedure:
   SCRIPT
   BEGIN  
     DECLARE DecVal DECIMAL(20,2);
     CALL ReturnDecimal(DecVal);
     SET LOG MESSAGE TO 'Result = ' + CAST(DecVal AS VARCHAR); 
   END

Create a delphi program and setup the engine, session, and database.  Then place both a TEDBQuery and a TEDBStoreProc component on the form. Set the query's SQL value to:

 SELECT DecimalValue() 
 FROM Configuration.DataTypes 
 WHERE NAME = 'Char' --anything to return a row

and point the stored procedure to point accordingly.  (Both should prepare CURRENCY parameters.)  Then set a button's OnClick event to the following:

 var
   FNVal: Currency;
   SPVal: Currency;
 begin
   // get value from function
   EDBQuery.Open;
   FNVal := EDBQuery.FieldByName('Value').AsCurrency;

   // get value from stored procedure
   EDBStoredProc.ExecProc;
   SPVal := EDBStoredProc.ParamByName('Value').AsCurrency;

   // show results
   MessageDlg(Format('Function call returned: %5.2f'#13#10 +
                     'Stored procedure returned: %5.2f',
                     [FNVal, SPVal]), mtInformation, [mbOK], 0);
 end;

 (--ALL CODE CAN BE FOUND IN THE BINARIES NEWSGROUP--)

What you SHOULD get is 1.3 and 1.2, respectively.
Instead, you get 1.0 and 1.2.