Abstract: A method for facilitating navigation among software applications and improved screen viewing in a Windows-based environment wherein a security based configurable primary menu is generated in a foreground of a display screen and an application is automatically spawned upon dropping of an object into a graphic element in the primary menu without resorting to additional initializations or spawning steps. Also, the security based configurable primary menu is automatically minimized and the corresponding running application windows are simultaneously removed from the viewing area in addition to the minimization of the primary menu.

Abstract: Transponder signal collision avoidance system incudes a reader and wireless HDX or FDX type transponders (A, B) are disclosed, interrogated by the reader (R) by alternately powering and then reading through cycles corresponding to a number of possible transponders in the interrogation field. The cycles, which include reader power pulses, signify addresses of respective possible transponders, whether in or out of the field. The transponders for this purpose count reader power pulses by end-of-burst detection, increasing a stored count value with each reader power pulse. The transponder responds to the reader by transmission if and only if a stored count value in a read cycle matches a respective transponder address, preventing the transponders from transmitting telegrams interfering with each other.

Abstract: A method is described with the aid of which messages can be transmitted from batteryless transponders to interrogation devices. The interrogation devices are equipped with a receiving section and a transmitting section and as a request to transmit the message stored therein as reaction to an interrogation command rendered effective in the interrogation device said devices transmit an HF interrogation pulse with predetermined carrier frequency and predetermined carrier duration. In the transponder this HF interrogation pulse is utilized to generate a supply voltage. Each interrogation device checks as reaction to an interrogation command whether its receiving section (14) is receiving a signal with the carrier frequency.

Abstract: A transponder arrangement is described having an interrogator unit (10) which transmits at least one RF programming sequence and at least one RF interrogation pulse. The responder unit (12) includes a responder unit receiver (130) for receiving data transmitted by the RF programming sequence from the interrogator unit (10). The responder unit (12) then upon receipt of the RF interrogation pulse transmits data, which may have been modified by the programming sequence from the interrogator unit (10), back to the interrogator unit (10) in the form of a modulated RF carrier. The responder unit (12) further comprises a responder unit energy accumulator (136) which stores energy contained in the RF interrogation pulse and a responder unit end of burst detector (142) which upon detection of a decreasing power level of the RF interrogation pulse sends a RF threshold signal.

Abstract: A Radio Frequency Identification (RFID) system having an interrogator (12) and a transponder (14). The interrogator has a first tuned circuit (28) of a powering frequency for sending a powering burst to a transponder (14), a filter/demodulator (64) for receiving an wireless, modulated RF response from a transponder (14). The interrogator (12) further has a second tuned circuit (29) in electrical communication with a modulator (48), the second tuned circuit (29) having a selected bandwidth about a communication frequency, the selected bandwidth not substantially overlapping the powering frequency and encompassing the bandwidth of the modulated carrier of the RF response.

Abstract: A method of communicating between an interrogator (10) and at least a first and second transponder (12). The transponders (12)are separately located within a first and a second vehicle (20) travelling within a first and a second traffic lane, respectively. The method has the steps of providing a first and a second LF antenna (16) associated with and proximity to a first and a second traffic lane, respectively. From each of the first and second LF antennas (16) a continuous LF subcarrier is transmitted to serve as a clock signal for each antenna's associated transponder (12). Initially, a wake-up signal is sent by each of the LF antennas (16) to its associated transponder (12). Following the wake-up signal, a unique lane code is sent by each of the LF antennas (16) to its associated transponder (12). The transponder (12) stores its unique lane code in its memory (70).

Abstract: A transponder arrangement is described having an interrogator unit (10) which transmits at least one RF programming sequence and at least one RF interrogation pulse. The responder unit (12) includes a responder unit receiver (130) for receiving data transmitted by the RF programming sequence from the interrogator unit (10). The responder unit (12) then upon receipt of the RF interrogation pulse transmits data, which may have been modified by the programming sequence from the interrogator unit (10), back to the interrogator unit (10) in the form of a modulated RF carrier. The responder unit (12) further comprises a responder unit energy accumulator (136) which stores energy contained in the RF interrogation pulse and a responder unit end of burst detector (142) which upon detection of a decreasing power level of the RF interrogation pulse sends a RF threshold signal.

Abstract: A hardware and software solution for providing a tamper-proof, batteryless, remote transponder which will only be programmable by an authorized user is disclosed. This goal is achieved through the use of a hardware Cyclic Redundancy Check (CRC) generator which checks during a WRITE function of the data that is received from the Reading/Writing (R/W) unit and also generates several protection bits (Block Check Character; BCC) which are sent back during the response function (READ). Before the CRC generator checks the data during a WRITE function, however, it must be set to a predetermined start value called a Segment Code, and the Segment Code of the R/W unit must be the same as the Segment Code of the transponder in order for a Write (or a READ) to be performed. Additionally, programming of the Selective Address must be done within a predetermined time window (has a predetermined Time Code).

Abstract: A method of communicating between an interrogator (10) and at least a first and second transponder (12). The transponders (12) are separately located within a first and a second vehicle (20) travelling within a first and a second traffic lane, respectively. The method has the steps of providing a first and a second LF antenna (16) associated with and proximity to a first and a second traffic lane, respectively. From each of the first and second LF antennas (16) a continuous LF subcarrier is transmitted to serve as a clock signal for each antenna's associated transponder (12). Initially, a wake-up signal is sent by each of the LF antennas (16) to its associated transponder (12). Following the wake-up signal, a unique lane code is sent by each of the LF antennas (16) to its associated transponder (12). The transponder (12) stores its unique lane code in its memory (70).

Abstract: A single interrogation device interrogates a plurality of transponders arranged within the range of transmission of the interrogation device and identifies them without any mutual interference.The interference free operation is obtained by the interrogation device sequentially transmitting a plurality of RF interrogation pulses, separated from each other in time and whose energy changes from one pulse to the next one, to transponders which have an energy storage element and which respond to the interrogation pulses with an answer signal in dependence upon the condition that, at the end of each interrogation pulse, the charge voltage present at the energy storage element falls within a predetermined voltage range.

Abstract: A battery-less transponder (12) for transmitting stored measurement data to an interrogation device (10) is described. The interrogation device (10) transmits an HF interrogation pulse for calling up the stored measurement data. The transponder (12) includes a resonant circuit (14) tuned to the frequency of the HF interrogation pulse, an energy storage element (C3) which is chargeable by rectification of the HF interrogation pulse and in the charged state furnishes the supply voltage for the transponder (12), and a voltage limiting means (Z, R) for limiting the voltage at the energy storage element (C3) to a predetermined voltage value. For detuning the resonance frequency thereof, a component (C4) of frequency-dependent impedance can be connected to the resonant circuit (14) via a switching element (T) which establishes the connection in dependence upon the starting of the limiting action by the voltage limiting means (Z, R).

Abstract: A circuit arrangement is described for generating pulses for maintaining the oscillations of a resonance circuit after termination of an outside stimulation of the oscillations by means of an HF carrier oscillation. The circuit arrangement comprises an energy storage element (28) chargeable by the HF carrier oscillation to a supply voltage value. An amplitude detector circuit (44) serves to generate a trigger circuit when the oscillation amplitude of the resonance circuit (12) drops beneath the supply voltage value. A first switching element (T2) supplies the oscillations of the resonance circuit (12) under the control of the trigger signal to a delay circuit (34, 53, 58, 54, 62, 68) which at its output furnishes switching pulses with a predetermined phase position with respect to the oscillations of the resonance circuit (12). A second switching element (T1), for the duration of each switching pulse, enables the supply of energy from the energy storage element (28) to the resonance circuit (12).

Abstract: A circuit arrangement is described with the aid of which a control signal can be indicated in dependence upon reaching a predetermined desired value voltage at an energy-storage element at the end of a charging cycle. In the course of said charging cycle the energy-storage element is charged by rectification of an HF carrier pulse. The circuit arrangement contains a signal-storage element (FF) which in the active state emits a control signal. Furthermore, an envelope detector circuit (DE, CE, RE, T2) is provided which furnishes a switching signal in dependence upon the termination of the HF carrier-oscillation pulse. A voltage comparator (R3, T3, R4, C2, R1, R2, OP) compares a voltage value dependent on the voltage value at the energy-storage element (CC) with a voltage value which is related to the voltage value at the energy-storage element (CC) in such a manner that in the presence of the desired voltage value at the energy-storage element (CC) the compared voltage values are equal.