Abstract: An electronic anti-shoplifting system monitors articles of merchandise in a sales outlet to deter shoplifting. The system is provided with transponder tags connected to the articles of merchandise. A tag exciter is positioned at an exit leading from the sales outlet and generates an RF surveillance excitation signal. If a customer carries an article through the exit without removal authorization due to failure to pay for the article, the transponder tag is activated, being powered by the RF surveillance excitation signal as the customer passes the tag exciter. The activated transponder tag generates an RF surveillance response signal that triggers an alarm. If the customer has removal authorization as the result of paying for the article, the transponder tag is reprogrammed to modify the operational data stored therein.

Abstract: A wireless modem employs a radio frequency (RF) transponder system components to remotely access the memory of an electrical or electro-mechanical device by providing an exciter/reader/writer (ERW) circuit free of electrical contact with the electrical or electro-mechanical device and a transponder including a transmit/receive antenna, a reading circuit, a programming circuit, and a transponder memory. The transponder memory is directly connected to the device memory. The ERW circuit initially generates an RF excitation signal powering the transponder. In response to the RF excitation signal, the transponder generates a RF response signal using the reading circuit that is transmitted back to the EWR circuit. The RF response signal includes data from the device memory. The RF response signal is received by the ERW circuit, which in turn generates an RF write signal that is transmitted to the transponder.