You can just press and hold the Light button for >1 second for infinite setting, a set time limit, set it for first keypress, or ignore the first keypress.
"Using the display/key backlight
Your PRO-97 features a backlit keypad and display for easy
viewing and use in dark environments. There are three
backlight modes you can choose from to control backlight
activation, Normal mode, Keypress mode, and fi rst keypress
Ignore mode.
With Normal mode, simply press to activate the backlight.
The backlight will activate and remain on for the factory
default setting of 5 seconds. The backlight continues to
remain on while you are operating the keypad. To turn off the
backlight before it automatically turns off, press again.
With Keypress mode, the backlight will light automatically
when you press any key on the keypad, and function as
described above in Normal mode. This mode is useful if
you want the backlight to come on automatically when you
perform an operation using the keypad.
With Ignore mode, the backlight functions as described in
Keypress mode, except that the scanner ignores the fi rst
keypress. This mode is useful when you wish to quickly
illuminate the display and keypad without having to search
for the key. The fi rst keypress is ignored, and the scanner
sounds the low pitched error beep to remind you that the
fi rst key pressed to activate the backlight is ignored by the
scanner.
In any backlight mode, you can press and hold for about 1
second to force the backlight on full time. Press while the
backlight is on to turn it off.
Follow these steps to change the backlight mode and
duration:
1. If the scanner is on, turn it off and back on again. Multi-
System Trunking Scanner appears in the scanner’s display.
2. While Multi-System Trunking Scanner appears, press .
3. Press e or d to select the desired backlight mode and
duration. Selecting 3, 5, 10, or 20 sets the backlight mode
for normal operation for the selected duration. Selecting
K3, K5, K10, or K20 sets the backlight mode for Keypress
operation for the selected duration. Selecting I3, I5, I10,
or I20 sets the backlight mode for Ignore operation for
the selected duration. Press ENT to store your selection."
You can also turn the Keybeep off:
"Turning the key tone on and off
Each time you press any of the scanner’s keys, the scanner
sounds a tone. To turn the scanner’s key tone off or on:
1. If the scanner is on, turn OFF/VOL counterclockwise until it
clicks to turn the scanner off.
2. Turn OFF/VOL clockwise to turn the scanner on. Multi-system
Trunking Scanner appears.
3. While Multi-system Trunking Scanner appears, press 1 to turn
on the key tone or 2 to turn it off."