Where is the Dio elevator safety circuit diode installed?

the small board below the board, the leftmost plug-in below is sealed to the rightmost plug-in below the board with the first thread. The elevator will not run when the safety circuit of the elevator is out of order. Because the safety circuit is connected in series with the power supply line of the main relay, some repairmen shorten the whole circuit and then reduce it again, depending on the operation of the elevator. This is a dangerous habit. In fact, each contact on the safety circuit is an on-off problem. As long as you measure it with a multimeter, you can determine that the contact in the safety circuit is broken, and it is much more convenient to repair it (note that a repair card must be erected when repairing).