| 摘要 |
<p>Systems for controlling the entrance into a lockable room (3), which may be movable or immovable, are known, for example in cars, whereby a first unit (5) is mounted inside the car and a second unit (7) is mounted in or on the car key, and for example in connection with the opening and closing of garage doors. A drawback is that one unit may change the code without the other unit being made aware of this (being out of range and the like). These problems are avoided by not carrying through the change until an OK signal (A) is received from the other unit. <IMAGE></p> |
