Abstract: A motor driven turnstile for providing cyclic access to a passage (16) to which a monitoring system or the like is allocated. The turnstile is controlled in such a way that, after a satisfactory monitoring result, each blocking arm (4) is first taken from the blocking position to a stopping position located at a small angle (alpha) from the blocking position, in which, after external pressure applied by the user, the arm is once again driven by the drive motor (6) and turned further until the next arm is in the blocking position.

Abstract: To permit visual monitoring of the owner of a data carrier in the form of a wrist-watch, a photo of the owner is incorporated in the clasp attached to the strap of the data carrier.

Abstract: For automated communication in a limited acquisition space, for example in order to identify or check an access authorization, use is made of active data supports which comprise a transmitter (15), a receiver (16), a read-write memory, an electric clock, a computer, a display and a power source (7). The checking station is also provided with a transmitter-receiver to check and possibly modify the data. Each transmitter-receiver has a limited communication space, of which the maximum extent is less than the minimum extent of the acquisition space. In this way it is not necessary to plug in the data support, of which a precise point must, however, be deliberately brought close to the checking station. In this way a definite coordination between the checking station and a further data support is prevented.

Abstract: An autonomous device that can be carried in one hand is used for checking and at least partially obliterating machine-readable data carriers. The device contains all components necessary to read and modify data and is provided with a card conveyor and a line-by-line printing device for processing data carriers having the form of card tokens.

Abstract: In order to control or identify an authorization of access, use is made of a control station which has two different read-write systems. The first unit is designed in particular for remote control of active date carriers comprising a microcomputer. The second read-write system is designed for the control of passive data carriers, on which the data are stored in a magnetic or optical form. Preferably both read-write systems are provided with parallel outputs, to which a switching system is connected, which passes to the peripheral systems the output signals produced by means of the desired data carrier.

Abstract: Methods and apparatuses for forgery security, issuing and monitoring or reducing the value of data carriers such as value cards, entitlement cards, travel tickets, etc., are described, the data being written into a magnetic layer. According to the method, physical authenticating features of the data carrier are evaluated as inhomogeneities in the magnetic layers which carry the data. Suitable data carriers comprise an individual and characteristic inhomogeneity produced, for example, by fluctuations in thickness, discontinuities (13) etc. The second side of the data carrier (1) is provided with an absorbent coating (15) which serves to receive ink sprayed on by an ink jet printer. For reading and/or coding the data carriers which are provided with two magnetic strips (12, 12') independently of the position of the data carriers, there are in an apparatus two reading-writing heads (60, 60') and two pressure applying rollers (61, 61.degree.