primary locking mechanism 3 which lifts the blocking action in order to ensure these marginal conditions a logic alignment takes place between the locking states of the primary and secondary locking mechanisms 3 5 namely preferably after a setting command has been released through one of the door openers 1 a 1 b 1 c or the locking button and after implementation of a setting movement produced by the motorized drive 2 the logic described above of releasing or blocking the access on the part of a door opener 1 a 1 b 1 c to the primary locking mechanism in dependence on its locking state can advantageously be reproduced by a mechanical scanning system whose function is not impaired by a current failure thus an emergency operation of the locking system is possible without impairing the security functions of the locking system the mechanical scanning can be undertaken by a scanner 52 which is connected to the secondary locking mechanism 5 b 5 c and is guided from a curved path 100 a 100 b 100 c or slide guide into the access position or into the blocking position fig2 a and 2 b show sections through the base body 10 a 10 b which support a curved path 100 a 100 b and are provided with a.