LG G Pad 7.0 V400 Guide De L'utilisateur page 273

To activate Knock Code feature
1
From the Home screen, tap Apps
screen > Select screen lock > Knock Code.
2 This opens a screen that will guide you through how to select the unlock
sequence. You have to create a backup PIN as a safety measure in case
you forget your unlock sequence.
NOTE: KnockON is disabled when Knock Code is in use.
> Settings > Display > Lock
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