Patent ID: 6163261
Filing Date: 2000-12-19
Classification: A01K,Y10S

Abstract:
A method of applying at least one of a stimulus and a warning signal to an animal, said method comprising the steps of:selecting a distance value between the animal and a transmitter;transmitting a radio frequency signal from said transmitter at a first point in time;receiving, at a time substantially equal to said first point in time, said radio frequency signal with a receiver attached to the animal;transmitting an ultrasonic frequency signal from said transmitter at a second point in time, a first time difference between said second point in time and said first point in time varying inversely with said selected distance value;receiving said ultrasonic frequency signal with said receiver at a third point in time;calculating a second time difference between said third point in time and said first point in time;determining whether the animal is beyond the distance value from said transmitter by comparing said second time difference with at least one threshold time difference; andselectively applying said at least one of a stimulus and a warning signal to the animal dependent upon said determining step.