The ML1200 may have a toggle switch that lets you switch between default and user defined on Chan 0, its shown in the manual in Chapter 4: http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1762-um001_-en-p.pdfYou have to create a program with the Channel configuration set for DH485, download to the ML1200, then (if installed) set the switch to the user defined position.