| 摘要 |
An electronic article surveillance system of type employing alarm tags releasably attachable to articles to be monitored, eg in a shop, comprises a transmitter unit (36) which radiates signals containing diverse message contents and tags (20). Each tag includes a pin type attachment device for releasably securing the tag to an article and incorporating switches 84, 86, 87 responsive to the state of the tag, a receiver (104) for receiving such radiated signals, a message decoder (120) for decoding the messages therein, a controller (90), an audio sequencer (128) and driver (132) having a piezo-electric output component and constituting an audible alarm unit, a switch monitor (82) for monitoring the switches 84, 86, 87, a retransmit sequencer (106) and tag antenna driver (144). The system is responsive to the state of the attachment device and to decoded messages for selectively operating the alarm unit to provide sensible output alarm indication. The messages may further be indicative of article identification and pricing, and the tags may effect display of price. An inventory store may be decremented upon check out of a tag carrying article, also an article price totalizer may be incremented. <IMAGE> |
