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Optical Break Locator
Table 4-1. Keypad functions.
Number Key
Function
1
Power:
Press this key to power on the unit. The unit will turn
off automatically if no keys are pressed for ten minutes. The
unit will turn on with the auto-off function deactivated when
you press the key for longer than two seconds. If you press
the key for longer than two seconds when the unit is pow-
ered on, the unit will shut down.
2
Cancel:
Press this key to exit the current working states.
3
Test:
Press this key to start a test.
4
Backlight:
Press this key and release it in less than two sec-
onds, and the backlight will turn on. But if you don’t press
another key within 30 seconds, the backlight will automati-
cally turn off. To deactivate the auto-off function
for backlight, press the key for longer than three seconds.
5
OK:
Press to confirm the current function and make sure the
data is saved to the correct position.
6
Up, Down arrow key.
7
Press these keys to switch between the storage function and
the refactive rate setting function. These keys also function as
left and right arrow keys.