For firmware versions 1.02-1.12: Display Options (ON, OFF, OFF1)
Select ON on the display setting to keep the menu unlocked. Backlight will remain on at all times.
For firmware versions 1.13-1.16: Display Options (OFF, ON, ON1)
Select OFF on the display setting to keep the menu unlocked. Backlight will turn off after 30 seconds, but menu will remain unlocked.