Line synchronized delays for multiple pulsed EAS systems

US5995002A · kind A · utility

Assignee

• Sensormatic Electronics, LLC · US

Inventors

• David B. Fallin · Coral Springs, US
• Brent F. Balch · Fort Lauderdale, US

Key dates

• Filing date: Nov 28, 1997
• Grant date: Nov 30, 1999
• Expiry date: Nov 28, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G08B13/2488
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A method for initializing an electronic article surveillance (EAS) system which transmits pulses into an interrogation zone and receives signals from the interrogation zone in a sequence of multiple successive transmit and receive windows during each line period of an AC mains supply energizing the EAS system, associated with a corresponding apparatus, comprises the steps of: (a.) determining whether a delay value is stored in a nonvolatile memory; (b.)if the delay value is stored in the nonvolatile memory, loading the stored delay value into a delay control register, terminating the initializing and omitting all remaining steps; (c.) if the delay value is not stored in the nonvolatile memory, loading a first delay value into the delay control register; (d.) determining whether noise in a certain receive window is less than a threshold level; (e.) if the noise is less than the threshold level, terminating the initializing and omitting all remaining steps; (f.) if the noise level is not less than the threshold level, loading a second delay value into the delay control register; (g.) determining if the EAS system is operating properly; (h.) if the EAS system is operating properly, te…