It will be listed under rate programming. I haven't got the table for this model since it is over ten years old and I haven't seen one for quite a while. If you haven't got the rate programming, one of the users has the programming manual for the NX5400 here:
http://the-checkout-tech.com/manuals/cashregisters/Uniwell_NX-5400_type_01_programming_manual.html
Registerman, April 2013