Rolling shutters with external bottom ground locks
1 . Open door protection, after the bottom beam is locked the controller is locked synchronously
2 . B grade blade lock core: will not have the same password in two different Bottom Ground Lock lock, strong enough that can not be forced open manually
3 . Delay opening: avoid miss receiving a signal by a fast unlock.
4 . Bottom Ground Lock After unlocking, if the rolling shutter door did not go up then lock again, the motor will stop work also