How to Restore the Initial Password of ACC?

Step 1 Disconnect the main power supply of the device.
Step 2 Set bits 1 and 3 of the DIP switch S2 to ON, and other bits to non ON.

Step 3 Connect the main power supply of the device.
Wait about 30s. All user passwords are restored to the initial ones.
Step 4 Disconnect the main power supply of the device.
Step 5 Set all bits of the DIP switch S2 to non ON.
Step 6 Connect the main power supply of the device.