I take guess... in case your text is too long to be shown entirely on your display, you should scroll right in time whenever it's needed. And then again, maybe Audya will remember your pace of scrolling and it will sync it automatically next time... I'll try it myself when I'll get home...
_________________________
Roland RD700 exp., Ketron Audya5, Ketron MIDJPRO, TC Helicon Harmony-M, EV N/D967, Shure Beta58A, Roland FR4X, Yamaha PSR SX900