English to Russian Tech/Engineering Engineering (general)

Перфоратор

AUXILIARY FUNCTION ON TILE
1) Press ON/OFF switch to see the light is on or off.
Light on indicates the auxiliary function is on, and light off indicate the auxiliary function is turn off.
2) When operating on the tile, press the auxiliary function button on tile (10) first, the green light on means that auxiliary function is on, then half-press switch, begin pulse auxiliary operation.

Не могу понять последнюю фразу: "then half-press switch, begin pulse auxiliary operation"

Спасибо