| 摘要 |
A device employing multiple local units (U1...Un) each of which controls a plurality of sensors (B), wherein said local units (U1...Un) are connected to one another and to a central processing unit (UC) via a communication network (RT) which includes at least one data transmission line (LD) and a clock signal transmission line (LK). Each of the local units (U1...Un) includes a device (F1, F2, F3) for counting the impulses it receives at its clock input, and two selectors (MU1, MU2) driven by said counting device, namely one selector for allowing clock signal transmission to the next local unit only after a predetermined time interval, and another selector for successively connecting the data transmission line to the abovementioned sensors and then to the local unit located downstream. The device is useful for providing protection against the theft of items which are on display or being demonstrated.
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