G
PHYSICS
G07
CHECKING-DEVICES
G07C
TIME OR ATTENDANCE REGISTERS; REGISTERING OR INDICATING THE WORKING OF MACHINES; GENERATING RANDOM NUMBERS; VOTING OR LOTTERY APPARATUS; ARRANGEMENTS, SYSTEMS OR APPARATUS FOR CHECKING NOT PROVIDED FOR ELSEWHERE
9/00
Individual registration on entry or exit
G07C9/00174
Electronically operated locks; Circuits therefor; Nonmechanical keys therefor, e.g. passive or active electrical keys or other data carriers without mechanical keys
G07C9/00182
operated with unidirectional data transmission between data carrier and locks
G07C2009/00238
the transmittted data signal containing a code which is changed
G07C2009/00253
dynamically, e.g. variable code - rolling code