Impact detection is deactivated by default. It can be activated in all three modes. i.e. Default mode, FT auto mode and FT manual mode.
How to Activate Impact Detection Mode

If an obstacle is
detected twice in the shade path during downwards movement, the motor lifts the shade up ~ 7.87in. (20cm).
The Impact Detection feature only works in the active zone as above picture during downward movement.
Repeat below sequence to turn on or off as required.
Relevant Documentation