For example, Ningbo Shenling Longmen Crane (Panasonic) mostly adopts four-switch mode, which has simple maintenance and low failure rate and is adopted by more manufacturers. If the above faults occur, most of them are switch position deviation or switch signal error (the controller has not received the signal).
Zhan Peng portal crane is also widely used, which uses encoder signal as input, and the error of opening and closing the door is also caused by the error of encoder signal.
What else is easy to rise, Amway, etc. Because there are too many kinds, it is impossible to tell them all.