Method for synchronization between systems
AssigneeSensormatic Electronics Corporation
InventorsStanley Strzelec, Brent Balch, Robert Lynch
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Abstract
An apparatus for synchronized operation of a plurality of EAS systems. The system includes two or more EAS systems. Each EAS system has a receiver for receiving the same RF synchronization signal sent from a remote source, a transmitter for transmitting a marker exciter pulse and an exciter pulse receiver. The transmitter and exciter pulse receiver of each of the EAS systems are selectively enabled a predetermined time after receiving the RF synchronization signal so that all EAS systems in a localized area can be synchronized with one another.
Claims20
A method for synchronizing the operation of a plurality of EAS systems, comprising:
- receiving in said plurality of EAS systems an single RF synchronization signal from a remote source;
- detecting a time difference between said RF syncyronization signal and zero crossing of at least one of a power line current and voltage and storing said difference in a memory;
- in response to receiving said RF synchronization signal, transmitting in each of said EAS systems a synchronized exciter pulse for exciting a remotely located identification marker;
- and
- a predetermined time after transmitting said exciter pulse, enabling in each of said EAS systems a receiver for detecting a characteristic response of said indentification marker.
An apparatus for synchronized operation of a plurality of EAS systems, comprising:
- a plurality of EAS system, each having a receiver for receiving a same RF synchronization signal sent from a remote source, a transmitter for transmitting an exciter pulse for exciting an indentification marker in response to said receiver receiving said RF synchronization signal, an exciter pulse receiver enable a predetermined time after transmitter transmits said exciter pulse receiver enabled a predetermined time after said transmitter transmits said exciter pulse, for detecting a characteristic response of said indentification marker, and a local power line zero crossing detector and a difference detector for detecting a time difference between said RF synchronization signal and a zero crossing of at least one of a power line current and voltage.
A method for synchronized operation of a plurality of EAS systems comprising:
- receiving in each said plurality of EAS systems a same RF synchronization signal;
- processing said RF synchronization signal in each of said plurality of EAS systems to determine a time offset relative to a predetermined angle of at least one of a power line voltage and current for each said EAS systems;
- storing in each said EAS system a time offset in a memory location;
- and
- transmitting in each of said EAS systems an exciter pulse for exciting a remotely located identification marker in accordance with said time offset.
Dependencies are inferred from the claim text.