| 摘要 |
<p>In a data transmission system comprising at least a data bank, data may be called from a subscriber station. In order that first data may be called by a first circle of authorized subscribers and that other data may be called only by a second circle of authorized subscriber, the subscriber station has a read out apparatus which authorizes the data call only when the data which may be read out from an authorization card to be inserted in the apparatus fulfil predetermined testing criteria. </p> |
