| 摘要 |
<p>An access-permitting system wherein all variable information relating to the authorization of the card within the access-permitting system, such as, for instance, with regard to the entrance(s) for which the card is valid and with regard to the point of time at or the period in which the card is valid, is provided on the card. Each time again, this information is rendered valid for a limited period of time, by means of a special card reader/writer which, unlike the other card readers belonging to the system, is connected to a central processing unit. Also, at the same moment, all information about access already permitted can be transferred from the card wherein this information is stored to the central processing unit. An access-permitting system according to the invention requires hardly any costly connections between the central processing unit and the decentral systems. <IMAGE></p> |
