Xinshida AS380S reports fault code 20. What does this mean and how to solve it?

Fault explanation: During operation (except maintenance), the leveling switch will not operate (non-emergency leveling) after the time set in F62 (anti-skid time).

Field investigation:

1、? Check the elevator shaft data to see if there are any floors above 8 meters high and install magnetic isolation plates.

2、? Check whether the flat floor signal changes when the elevator runs to the door area.

3、? Check whether the value setting of F62 is too small, up to 45 seconds.

4、? Check whether the main board does not output the running speed when the elevator is running.