Using OUT parameter in MySQL stored procedure?

[Ness]

How can I get multiple values back from multiple SQL statements in a stored procedure in MySQL?

Stored Procedure:

CREATE DEFINER=`root`@`localhost` PROCEDURE `get_test`(OUT var1 INT, OUT var2 INT )
BEGIN
SELECT Temperature into var1 FROM `interface`.`setpoints` WHERE Area = 1;
SELECT Temperature into var2 FROM `interface`.`setpoints` WHERE Area = 2;
SELECT var1, var2;
END

In MySQL Workbench:

CALL `interface`.`get_test`(@a1,@a2);

Result Grid shows:
var1 | var2
750  | 850

 

In UniLogic my Query is:
 

CALL get_test(:a,:b);

The query executes successfully but doesn't return any values. The two tags tied to the Query Outputs keep their current values and aren't changed.

Do I just need the proper SQL incantation to get this working? Or are out parameters not supported with UniLogic?